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- /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
- /* ***** BEGIN LICENSE BLOCK *****
- * Version: MPL 1.1/GPL 2.0/LGPL 2.1
- *
- * The contents of this file are subject to the Mozilla Public License Version
- * 1.1 (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- * http://www.mozilla.org/MPL/
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- *
- * The Original Code is mozilla.org code.
- *
- * The Initial Developer of the Original Code is
- * Netscape Communications Corporation.
- * Portions created by the Initial Developer are Copyright (C) 1999
- * the Initial Developer. All Rights Reserved.
- *
- * Contributor(s):
- * Blake Ross (blake@blakeross.com)
- *
- * Alternatively, the contents of this file may be used under the terms of
- * either of the GNU General Public License Version 2 or later (the "GPL"),
- * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- * in which case the provisions of the GPL or the LGPL are applicable instead
- * of those above. If you wish to allow use of your version of this file only
- * under the terms of either the GPL or the LGPL, and not to allow others to
- * use your version of this file under the terms of the MPL, indicate your
- * decision by deleting the provisions above and replace them with the notice
- * and other provisions required by the GPL or the LGPL. If you do not delete
- * the provisions above, a recipient may use your version of this file under
- * the terms of any one of the MPL, the GPL or the LGPL.
- *
- * ***** END LICENSE BLOCK ***** */
-
- #ifndef _MDB_
- #define _MDB_ 1
-
- #include "nscore.h"
- #include "nsISupports.h"
- //3456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789
-
- // { %%%%% begin scalar typedefs %%%%%
- typedef unsigned char mdb_u1; // make sure this is one byte
- typedef unsigned short mdb_u2; // make sure this is two bytes
- typedef short mdb_i2; // make sure this is two bytes
- typedef PRUint32 mdb_u4; // make sure this is four bytes
- typedef PRInt32 mdb_i4; // make sure this is four bytes
- typedef PRWord mdb_ip; // make sure sizeof(mdb_ip) == sizeof(void*)
-
- typedef mdb_u1 mdb_bool; // unsigned byte with zero=false, nonzero=true
-
- /* canonical boolean constants provided only for code clarity: */
- #define mdbBool_kTrue ((mdb_bool) 1) /* actually any nonzero means true */
- #define mdbBool_kFalse ((mdb_bool) 0) /* only zero means false */
-
- typedef mdb_u4 mdb_id; // unsigned object identity in a scope
- typedef mdb_id mdb_rid; // unsigned row identity inside scope
- typedef mdb_id mdb_tid; // unsigned table identity inside scope
- typedef mdb_u4 mdb_token; // unsigned token for atomized string
- typedef mdb_token mdb_scope; // token used to id scope for rows
- typedef mdb_token mdb_kind; // token used to id kind for tables
- typedef mdb_token mdb_column; // token used to id columns for rows
- typedef mdb_token mdb_cscode; // token used to id charset names
- typedef mdb_u4 mdb_seed; // unsigned collection change counter
- typedef mdb_u4 mdb_count; // unsigned collection member count
- typedef mdb_u4 mdb_size; // unsigned physical media size
- typedef mdb_u4 mdb_fill; // unsigned logical content size
- typedef mdb_u4 mdb_more; // more available bytes for larger buffer
-
- #define mdbId_kNone ((mdb_id) -1) /* never a valid Mork object ID */
-
- typedef mdb_u4 mdb_percent; // 0..100, with values >100 same as 100
-
- typedef mdb_u1 mdb_priority; // 0..9, for a total of ten different values
-
- // temporary substitute for NS_RESULT, for mdb.h standalone compilation:
- typedef nsresult mdb_err; // equivalent to NS_RESULT
-
- // sequence position is signed; negative is useful to mean "before first":
- typedef mdb_i4 mdb_pos; // signed zero-based ordinal collection position
-
- #define mdbPos_kBeforeFirst ((mdb_pos) -1) /* any negative is before zero */
-
- // order is also signed, so we can use three states for comparison order:
- typedef mdb_i4 mdb_order; // neg:lessthan, zero:equalto, pos:greaterthan
-
- typedef mdb_order (* mdbAny_Order)(const void* inA, const void* inB,
- const void* inClosure);
-
- // } %%%%% end scalar typedefs %%%%%
-
- // { %%%%% begin C structs %%%%%
-
- #ifndef mdbScopeStringSet_typedef
- typedef struct mdbScopeStringSet mdbScopeStringSet;
- #define mdbScopeStringSet_typedef 1
- #endif
-
- /*| mdbScopeStringSet: a set of null-terminated C strings that enumerate some
- **| names of row scopes, so that row scopes intended for use by an application
- **| can be declared by an app when trying to open or create a database file.
- **| (We use strings and not tokens because we cannot know the tokens for any
- **| particular db without having first opened the db.) The goal is to inform
- **| a db runtime that scopes not appearing in this list can be given relatively
- **| short shrift in runtime representation, with the expectation that other
- **| scopes will not actually be used. However, a db should still be prepared
- **| to handle accessing row scopes not in this list, rather than raising errors.
- **| But it could be quite expensive to access a row scope not on the list.
- **| Note a zero count for the string set means no such string set is being
- **| specified, and that a db should handle all row scopes efficiently.
- **| (It does NOT mean an app plans to use no content whatsoever.)
- |*/
- #ifndef mdbScopeStringSet_struct
- #define mdbScopeStringSet_struct 1
- struct mdbScopeStringSet { // vector of scopes for use in db opening policy
- // when mScopeStringSet_Count is zero, this means no scope constraints
- mdb_count mScopeStringSet_Count; // number of strings in vector below
- const char** mScopeStringSet_Strings; // null-ended ascii scope strings
- };
- #endif /*mdbScopeStringSet_struct*/
-
- #ifndef mdbOpenPolicy_typedef
- typedef struct mdbOpenPolicy mdbOpenPolicy;
- #define mdbOpenPolicy_typedef 1
- #endif
-
- #ifndef mdbOpenPolicy_struct
- #define mdbOpenPolicy_struct 1
- struct mdbOpenPolicy { // policies affecting db usage for ports and stores
- mdbScopeStringSet mOpenPolicy_ScopePlan; // predeclare scope usage plan
- mdb_bool mOpenPolicy_MaxLazy; // nonzero: do least work
- mdb_bool mOpenPolicy_MinMemory; // nonzero: use least memory
- };
- #endif /*mdbOpenPolicy_struct*/
-
- #ifndef mdbTokenSet_typedef
- typedef struct mdbTokenSet mdbTokenSet;
- #define mdbTokenSet_typedef 1
- #endif
-
- #ifndef mdbTokenSet_struct
- #define mdbTokenSet_struct 1
- struct mdbTokenSet { // array for a set of tokens, and actual slots used
- mdb_count mTokenSet_Count; // number of token slots in the array
- mdb_fill mTokenSet_Fill; // the subset of count slots actually used
- mdb_more mTokenSet_More; // more tokens available for bigger array
- mdb_token* mTokenSet_Tokens; // array of count mdb_token instances
- };
- #endif /*mdbTokenSet_struct*/
-
- #ifndef mdbUsagePolicy_typedef
- typedef struct mdbUsagePolicy mdbUsagePolicy;
- #define mdbUsagePolicy_typedef 1
- #endif
-
- /*| mdbUsagePolicy: another version of mdbOpenPolicy which uses tokens instead
- **| of scope strings, because usage policies can be constructed for use with a
- **| db that is already open, while an open policy must be constructed before a
- **| db has yet been opened.
- |*/
- #ifndef mdbUsagePolicy_struct
- #define mdbUsagePolicy_struct 1
- struct mdbUsagePolicy { // policies affecting db usage for ports and stores
- mdbTokenSet mUsagePolicy_ScopePlan; // current scope usage plan
- mdb_bool mUsagePolicy_MaxLazy; // nonzero: do least work
- mdb_bool mUsagePolicy_MinMemory; // nonzero: use least memory
- };
- #endif /*mdbUsagePolicy_struct*/
-
- #ifndef mdbOid_typedef
- typedef struct mdbOid mdbOid;
- #define mdbOid_typedef 1
- #endif
-
- #ifndef mdbOid_struct
- #define mdbOid_struct 1
- struct mdbOid { // identity of some row or table inside a database
- mdb_scope mOid_Scope; // scope token for an id's namespace
- mdb_id mOid_Id; // identity of object inside scope namespace
- };
- #endif /*mdbOid_struct*/
-
- #ifndef mdbRange_typedef
- typedef struct mdbRange mdbRange;
- #define mdbRange_typedef 1
- #endif
-
- #ifndef mdbRange_struct
- #define mdbRange_struct 1
- struct mdbRange { // range of row positions in a table
- mdb_pos mRange_FirstPos; // position of first row
- mdb_pos mRange_LastPos; // position of last row
- };
- #endif /*mdbRange_struct*/
-
- #ifndef mdbColumnSet_typedef
- typedef struct mdbColumnSet mdbColumnSet;
- #define mdbColumnSet_typedef 1
- #endif
-
- #ifndef mdbColumnSet_struct
- #define mdbColumnSet_struct 1
- struct mdbColumnSet { // array of column tokens (just the same as mdbTokenSet)
- mdb_count mColumnSet_Count; // number of columns
- mdb_column* mColumnSet_Columns; // count mdb_column instances
- };
- #endif /*mdbColumnSet_struct*/
-
- #ifndef mdbYarn_typedef
- typedef struct mdbYarn mdbYarn;
- #define mdbYarn_typedef 1
- #endif
-
- #ifdef MDB_BEGIN_C_LINKAGE_define
- #define MDB_BEGIN_C_LINKAGE_define 1
- #define MDB_BEGIN_C_LINKAGE extern "C" {
- #define MDB_END_C_LINKAGE }
- #endif /*MDB_BEGIN_C_LINKAGE_define*/
-
- /*| mdbYarn_mGrow: an abstract API for growing the size of a mdbYarn
- **| instance. With respect to a specific API that requires a caller
- **| to supply a string (mdbYarn) that a callee fills with content
- **| that might exceed the specified size, mdbYarn_mGrow is a caller-
- **| supplied means of letting a callee attempt to increase the string
- **| size to become large enough to receive all content available.
- **|
- **|| Grow(): a method for requesting that a yarn instance be made
- **| larger in size. Note that such requests need not be honored, and
- **| need not be honored in full if only partial size growth is desired.
- **| (Note that no nsIMdbEnv instance is passed as argument, although one
- **| might be needed in some circumstances. So if an nsIMdbEnv is needed,
- **| a reference to one might be held inside a mdbYarn member slot.)
- **|
- **|| self: a yarn instance to be grown. Presumably this yarn is
- **| the instance which holds the mYarn_Grow method pointer. Yarn
- **| instancesshould only be passed to grow methods which they were
- **| specifically designed to fit, as indicated by the mYarn_Grow slot.
- **|
- **|| inNewSize: the new desired value for slot mYarn_Size in self.
- **| If mYarn_Size is already this big, then nothing should be done.
- **| If inNewSize is larger than seems feasible or desirable to honor,
- **| then any size restriction policy can be used to grow to some size
- **| greater than mYarn_Size. (Grow() might even grow to a size
- **| greater than inNewSize in order to make the increase in size seem
- **| worthwhile, rather than growing in many smaller steps over time.)
- |*/
- typedef void (* mdbYarn_mGrow)(mdbYarn* self, mdb_size inNewSize);
- // mdbYarn_mGrow methods must be declared with C linkage in C++
-
- /*| mdbYarn: a variable length "string" of arbitrary binary bytes,
- **| whose length is mYarn_Fill, inside a buffer mYarn_Buf that has
- **| at most mYarn_Size byte of physical space.
- **|
- **|| mYarn_Buf: a pointer to space containing content. This slot
- **| might never be nil when mYarn_Size is nonzero, but checks for nil
- **| are recommended anyway.
- **| (Implementations of mdbYarn_mGrow methods should take care to
- **| ensure the existence of a replacement before dropping old Bufs.)
- **| Content in Buf can be anything in any format, but the mYarn_Form
- **| implies the actual format by some caller-to-callee convention.
- **| mYarn_Form==0 implies US-ASCII iso-8859-1 Latin1 string content.
- **|
- **|| mYarn_Size: the physical size of Buf in bytes. Note that if one
- **| intends to terminate a string with a null byte, that it must not
- **| be written at or after mYarn_Buf[mYarn_Size] because this is after
- **| the last byte in the physical buffer space. Size can be zero,
- **| which means the string has no content whatsoever; note that when
- **| Size is zero, this is a suitable reason for Buf==nil as well.
- **|
- **|| mYarn_Fill: the logical content in Buf in bytes, where Fill must
- **| never exceed mYarn_Size. Note that yarn strings might not have a
- **| terminating null byte (since they might not even be C strings), but
- **| when they do, such terminating nulls are considered part of content
- **| and therefore Fill will count such null bytes. So an "empty" C
- **| string will have Fill==1, because content includes one null byte.
- **| Fill does not mean "length" when applied to C strings for this
- **| reason. However, clients using yarns to hold C strings can infer
- **| that length is equal to Fill-1 (but should take care to handle the
- **| case where Fill==0). To be paranoid, one can always copy to a
- **| destination with size exceeding Fill, and place a redundant null
- **| byte in the Fill position when this simplifies matters.
- **|
- **|| mYarn_Form: a designation of content format within mYarn_Buf.
- **| The semantics of this slot are the least well defined, since the
- **| actual meaning is context dependent, to the extent that callers
- **| and callees must agree on format encoding conventions when such
- **| are not standardized in many computing contexts. However, in the
- **| context of a specific mdb database, mYarn_Form is a token for an
- **| atomized string in that database that typically names a preferred
- **| mime type charset designation. If and when mdbYarn is used for
- **| other purposes away from the mdb interface, folks can use another
- **| convention system for encoding content formats. However, in all
- **| contexts is it useful to maintain the convention that Form==0
- **| implies Buf contains US-ASCII iso-8859-1 Latin1 string content.
- **|
- **|| mYarn_Grow: either a mdbYarn_mGrow method, or else nil. When
- **| a mdbYarn_mGrow method is provided, this method can be used to
- **| request a yarn buf size increase. A caller who constructs the
- **| original mdbYarn instance decides whether a grow method is necessary
- **| or desirable, and uses only grow methods suitable for the buffering
- **| nature of a specific mdbYarn instance. (For example, Buf might be a
- **| staticly allocated string space which switches to something heap-based
- **| when grown, and subsequent calls to grow the yarn must distinguish the
- **| original static string from heap allocated space, etc.) Note that the
- **| method stored in mYarn_Grow can change, and this might be a common way
- **| to track memory managent changes in policy for mYarn_Buf.
- |*/
- #ifndef mdbYarn_struct
- #define mdbYarn_struct 1
- struct mdbYarn { // buffer with caller space allocation semantics
- void* mYarn_Buf; // space for holding any binary content
- mdb_fill mYarn_Fill; // logical content in Buf in bytes
- mdb_size mYarn_Size; // physical size of Buf in bytes
- mdb_more mYarn_More; // more available bytes if Buf is bigger
- mdb_cscode mYarn_Form; // charset format encoding
- mdbYarn_mGrow mYarn_Grow; // optional method to grow mYarn_Buf
-
- // Subclasses might add further slots after mYarn_Grow in order to
- // maintain bookkeeping needs, such as state info about mYarn_Buf.
- };
- #endif /*mdbYarn_struct*/
-
- // } %%%%% end C structs %%%%%
-
- // { %%%%% begin class forward defines %%%%%
- class nsIMdbEnv;
- class nsIMdbObject;
- class nsIMdbErrorHook;
- class nsIMdbCompare;
- class nsIMdbThumb;
- class nsIMdbFactory;
- class nsIMdbFile;
- class nsIMdbPort;
- class nsIMdbStore;
- class nsIMdbCursor;
- class nsIMdbPortTableCursor;
- class nsIMdbCollection;
- class nsIMdbTable;
- class nsIMdbTableRowCursor;
- class nsIMdbRow;
- class nsIMdbRowCellCursor;
- class nsIMdbBlob;
- class nsIMdbCell;
- class nsIMdbSorting;
- // } %%%%% end class forward defines %%%%%
-
-
- // { %%%%% begin C++ abstract class interfaces %%%%%
-
- /*| nsIMdbObject: base class for all message db class interfaces
- **|
- **|| factory: all nsIMdbObjects from the same code suite have the same factory
- **|
- **|| refcounting: both strong and weak references, to ensure strong refs are
- **| acyclic, while weak refs can cause cycles. CloseMdbObject() is
- **| called when (strong) use counts hit zero, but clients can call this close
- **| method early for some reason, if absolutely necessary even though it will
- **| thwart the other uses of the same object. Note that implementations must
- **| cope with close methods being called arbitrary numbers of times. The COM
- **| calls to AddRef() and release ref map directly to strong use ref calls,
- **| but the total ref count for COM objects is the sum of weak & strong refs.
- |*/
-
- #define NS_IMDBOBJECT_IID_STR "5533ea4b-14c3-4bef-ac60-22f9e9a49084"
-
- #define NS_IMDBOBJECT_IID \
- {0x5533ea4b, 0x14c3, 0x4bef, \
- { 0xac, 0x60, 0x22, 0xf9, 0xe9, 0xa4, 0x90, 0x84}}
-
- class nsIMdbObject : public nsISupports { // msg db base class
- public:
-
- NS_DEFINE_STATIC_IID_ACCESSOR(NS_IMDBOBJECT_IID)
- // { ===== begin nsIMdbObject methods =====
-
- // { ----- begin attribute methods -----
- NS_IMETHOD IsFrozenMdbObject(nsIMdbEnv* ev, mdb_bool* outIsReadonly) = 0;
- // same as nsIMdbPort::GetIsPortReadonly() when this object is inside a port.
- // } ----- end attribute methods -----
-
- // { ----- begin factory methods -----
- NS_IMETHOD GetMdbFactory(nsIMdbEnv* ev, nsIMdbFactory** acqFactory) = 0;
- // } ----- end factory methods -----
-
- // { ----- begin ref counting for well-behaved cyclic graphs -----
- NS_IMETHOD GetWeakRefCount(nsIMdbEnv* ev, // weak refs
- mdb_count* outCount) = 0;
- NS_IMETHOD GetStrongRefCount(nsIMdbEnv* ev, // strong refs
- mdb_count* outCount) = 0;
-
- NS_IMETHOD AddWeakRef(nsIMdbEnv* ev) = 0;
- NS_IMETHOD AddStrongRef(nsIMdbEnv* ev) = 0;
-
- NS_IMETHOD CutWeakRef(nsIMdbEnv* ev) = 0;
- NS_IMETHOD CutStrongRef(nsIMdbEnv* ev) = 0;
-
- NS_IMETHOD CloseMdbObject(nsIMdbEnv* ev) = 0; // called at strong refs zero
- NS_IMETHOD IsOpenMdbObject(nsIMdbEnv* ev, mdb_bool* outOpen) = 0;
- // } ----- end ref counting -----
-
- // } ===== end nsIMdbObject methods =====
- };
-
- /*| nsIMdbErrorHook: a base class for clients of this API to subclass, in order
- **| to provide a callback installable in nsIMdbEnv for error notifications. If
- **| apps that subclass nsIMdbErrorHook wish to maintain a reference to the env
- **| that contains the hook, then this should be a weak ref to avoid cycles.
- **|
- **|| OnError: when nsIMdbEnv has an error condition that causes the total count
- **| of errors to increase, then nsIMdbEnv should call OnError() to report the
- **| error in some fashion when an instance of nsIMdbErrorHook is installed. The
- **| variety of string flavors is currently due to the uncertainty here in the
- **| nsIMdbBlob and nsIMdbCell interfaces. (Note that overloading by using the
- **| same method name is not necessary here, and potentially less clear.)
- |*/
- class nsIMdbErrorHook : public nsISupports{ // env callback handler to report errors
- public:
-
- // { ===== begin error methods =====
- NS_IMETHOD OnErrorString(nsIMdbEnv* ev, const char* inAscii) = 0;
- NS_IMETHOD OnErrorYarn(nsIMdbEnv* ev, const mdbYarn* inYarn) = 0;
- // } ===== end error methods =====
-
- // { ===== begin warning methods =====
- NS_IMETHOD OnWarningString(nsIMdbEnv* ev, const char* inAscii) = 0;
- NS_IMETHOD OnWarningYarn(nsIMdbEnv* ev, const mdbYarn* inYarn) = 0;
- // } ===== end warning methods =====
-
- // { ===== begin abort hint methods =====
- NS_IMETHOD OnAbortHintString(nsIMdbEnv* ev, const char* inAscii) = 0;
- NS_IMETHOD OnAbortHintYarn(nsIMdbEnv* ev, const mdbYarn* inYarn) = 0;
- // } ===== end abort hint methods =====
- };
-
- /*| nsIMdbCompare: a caller-supplied yarn comparison interface. When two yarns
- **| are compared to each other with Order(), this method should return a signed
- **| long integer denoting relation R between the 1st and 2nd yarn instances
- **| such that (First R Second), where negative is less than, zero is equal to,
- **| and positive is greater than. Note that both yarns are readonly, and the
- **| Order() method should make no attempt to modify the yarn content.
- |*/
- class nsIMdbCompare { // caller-supplied yarn comparison
- public:
-
- // { ===== begin nsIMdbCompare methods =====
- NS_IMETHOD Order(nsIMdbEnv* ev, // compare first to second yarn
- const mdbYarn* inFirst, // first yarn in comparison
- const mdbYarn* inSecond, // second yarn in comparison
- mdb_order* outOrder) = 0; // negative="<", zero="=", positive=">"
-
- NS_IMETHOD AddStrongRef(nsIMdbEnv* ev) = 0; // does nothing
- NS_IMETHOD CutStrongRef(nsIMdbEnv* ev) = 0; // does nothing
- // } ===== end nsIMdbCompare methods =====
-
- };
-
- /*| nsIMdbHeap: abstract memory allocation interface.
- **|
- **|| Alloc: return a block at least inSize bytes in size with alignment
- **| suitable for any native type (such as long integers). When no such
- **| block can be allocated, failure is indicated by a null address in
- **| addition to reporting an error in the environment.
- **|
- **|| Free: deallocate a block allocated or resized earlier by the same
- **| heap instance. If the inBlock parameter is nil, the heap should do
- **| nothing (and crashing is strongly discouraged).
- |*/
- class nsIMdbHeap { // caller-supplied memory management interface
- public:
- // { ===== begin nsIMdbHeap methods =====
- NS_IMETHOD Alloc(nsIMdbEnv* ev, // allocate a piece of memory
- mdb_size inSize, // requested byte size of new memory block
- void** outBlock) = 0; // memory block of inSize bytes, or nil
-
- NS_IMETHOD Free(nsIMdbEnv* ev, // free block from Alloc or Resize()
- void* ioBlock) = 0; // block to be destroyed/deallocated
-
- NS_IMETHOD HeapAddStrongRef(nsIMdbEnv* ev) = 0;
- NS_IMETHOD HeapCutStrongRef(nsIMdbEnv* ev) = 0;
-
- // } ===== end nsIMdbHeap methods =====
- };
-
- /*| nsIMdbCPlusHeap: Alloc() with global ::new(), Free() with global ::delete().
- **| Resize() is done by ::new() followed by ::delete().
- |*/
- class nsIMdbCPlusHeap { // caller-supplied memory management interface
- public:
- // { ===== begin nsIMdbHeap methods =====
- NS_IMETHOD Alloc(nsIMdbEnv* ev, // allocate a piece of memory
- mdb_size inSize, // requested size of new memory block
- void** outBlock); // memory block of inSize bytes, or nil
-
- NS_IMETHOD Free(nsIMdbEnv* ev, // free block allocated earlier by Alloc()
- void* inBlock);
-
- NS_IMETHOD HeapAddStrongRef(nsIMdbEnv* ev);
- NS_IMETHOD HeapCutStrongRef(nsIMdbEnv* ev);
- // } ===== end nsIMdbHeap methods =====
- };
-
- /*| nsIMdbThumb:
- |*/
-
-
- #define NS_IMDBTHUMB_IID_STR "6d3ad7c1-a809-4e74-8577-49fa9a4562fa"
-
- #define NS_IMDBTHUMB_IID \
- {0x6d3ad7c1, 0xa809, 0x4e74, \
- { 0x85, 0x77, 0x49, 0xfa, 0x9a, 0x45, 0x62, 0xfa}}
-
-
- class nsIMdbThumb : public nsISupports { // closure for repeating incremental method
- public:
- NS_DEFINE_STATIC_IID_ACCESSOR(NS_IMDBTHUMB_IID)
-
- // { ===== begin nsIMdbThumb methods =====
- NS_IMETHOD GetProgress(nsIMdbEnv* ev,
- mdb_count* outTotal, // total somethings to do in operation
- mdb_count* outCurrent, // subportion of total completed so far
- mdb_bool* outDone, // is operation finished?
- mdb_bool* outBroken // is operation irreparably dead and broken?
- ) = 0;
-
- NS_IMETHOD DoMore(nsIMdbEnv* ev,
- mdb_count* outTotal, // total somethings to do in operation
- mdb_count* outCurrent, // subportion of total completed so far
- mdb_bool* outDone, // is operation finished?
- mdb_bool* outBroken // is operation irreparably dead and broken?
- ) = 0;
-
- NS_IMETHOD CancelAndBreakThumb( // cancel pending operation
- nsIMdbEnv* ev) = 0;
- // } ===== end nsIMdbThumb methods =====
- };
-
- /*| nsIMdbEnv: a context parameter used when calling most abstract db methods.
- **| The main purpose of such an object is to permit a database implementation
- **| to avoid the use of globals to share information between various parts of
- **| the implementation behind the abstract db interface. An environment acts
- **| like a session object for a given calling thread, and callers should use
- **| at least one different nsIMdbEnv instance for each thread calling the API.
- **| While the database implementation might not be threaded, it is highly
- **| desirable that the db be thread-safe if calling threads use distinct
- **| instances of nsIMdbEnv. Callers can stop at one nsIMdbEnv per thread, or they
- **| might decide to make on nsIMdbEnv instance for every nsIMdbPort opened, so that
- **| error information is segregated by database instance. Callers create
- **| instances of nsIMdbEnv by calling the MakeEnv() method in nsIMdbFactory.
- **|
- **|| tracing: an environment might support some kind of tracing, and this
- **| boolean attribute permits such activity to be enabled or disabled.
- **|
- **|| errors: when a call to the abstract db interface returns, a caller might
- **| check the number of outstanding errors to see whether the operation did
- **| actually succeed. Each nsIMdbEnv should have all its errors cleared by a
- **| call to ClearErrors() before making each call to the abstract db API,
- **| because outstanding errors might disable further database actions. (This
- **| is not done inside the db interface, because the db cannot in general know
- **| when a call originates from inside or outside -- only the app knows this.)
- **|
- **|| error hook: callers can install an instance of nsIMdbErrorHook to receive
- **| error notifications whenever the error count increases. The hook can
- **| be uninstalled by passing a null pointer.
- **|
- |*/
-
- #define NS_IMDBENV_IID_STR "a765e46b-efb6-41e6-b75b-c5d6bd710594"
-
- #define NS_IMDBENV_IID \
- {0xa765e46b, 0xefb6, 0x41e6, \
- { 0xb7, 0x5b, 0xc5, 0xd6, 0xbd, 0x71, 0x05, 0x94}}
-
- class nsIMdbEnv : public nsISupports { // db specific context parameter
- public:
-
- NS_DEFINE_STATIC_IID_ACCESSOR(NS_IMDBENV_IID)
- // { ===== begin nsIMdbEnv methods =====
-
- // { ----- begin attribute methods -----
- NS_IMETHOD GetErrorCount(mdb_count* outCount,
- mdb_bool* outShouldAbort) = 0;
- NS_IMETHOD GetWarningCount(mdb_count* outCount,
- mdb_bool* outShouldAbort) = 0;
-
- NS_IMETHOD GetEnvBeVerbose(mdb_bool* outBeVerbose) = 0;
- NS_IMETHOD SetEnvBeVerbose(mdb_bool inBeVerbose) = 0;
-
- NS_IMETHOD GetDoTrace(mdb_bool* outDoTrace) = 0;
- NS_IMETHOD SetDoTrace(mdb_bool inDoTrace) = 0;
-
- NS_IMETHOD GetAutoClear(mdb_bool* outAutoClear) = 0;
- NS_IMETHOD SetAutoClear(mdb_bool inAutoClear) = 0;
-
- NS_IMETHOD GetErrorHook(nsIMdbErrorHook** acqErrorHook) = 0;
- NS_IMETHOD SetErrorHook(
- nsIMdbErrorHook* ioErrorHook) = 0; // becomes referenced
-
- NS_IMETHOD GetHeap(nsIMdbHeap** acqHeap) = 0;
- NS_IMETHOD SetHeap(
- nsIMdbHeap* ioHeap) = 0; // becomes referenced
- // } ----- end attribute methods -----
-
- NS_IMETHOD ClearErrors() = 0; // clear errors beore re-entering db API
- NS_IMETHOD ClearWarnings() = 0; // clear warnings
- NS_IMETHOD ClearErrorsAndWarnings() = 0; // clear both errors & warnings
- // } ===== end nsIMdbEnv methods =====
- };
-
- /*| nsIMdbFactory: the main entry points to the abstract db interface. A DLL
- **| that supports this mdb interface need only have a single exported method
- **| that will return an instance of nsIMdbFactory, so that further methods in
- **| the suite can be accessed from objects returned by nsIMdbFactory methods.
- **|
- **|| mdbYarn: note all nsIMdbFactory subclasses must guarantee null
- **| termination of all strings written into mdbYarn instances, as long as
- **| mYarn_Size and mYarn_Buf are nonzero. Even truncated string values must
- **| be null terminated. This is more strict behavior than mdbYarn requires,
- **| but it is part of the nsIMdbFactory interface.
- **|
- **|| envs: an environment instance is required as per-thread context for
- **| most of the db method calls, so nsIMdbFactory creates such instances.
- **|
- **|| rows: callers must be able to create row instances that are independent
- **| of storage space that is part of the db content graph. Many interfaces
- **| for data exchange have strictly copy semantics, so that a row instance
- **| has no specific identity inside the db content model, and the text in
- **| cells are an independenty copy of unexposed content inside the db model.
- **| Callers are expected to maintain one or more row instances as a buffer
- **| for staging cell content copied into or out of a table inside the db.
- **| Callers are urged to use an instance of nsIMdbRow created by the nsIMdbFactory
- **| code suite, because reading and writing might be much more efficient than
- **| when using a hand-rolled nsIMdbRow subclass with no relation to the suite.
- **|
- **|| ports: a port is a readonly interface to a specific database file. Most
- **| of the methods to access a db file are suitable for a readonly interface,
- **| so a port is the basic minimum for accessing content. This makes it
- **| possible to read other external formats for import purposes, without
- **| needing the code or competence necessary to write every such format. So
- **| we can write generic import code just once, as long as every format can
- **| show a face based on nsIMdbPort. (However, same suite import can be faster.)
- **| Given a file name and the first 512 bytes of a file, a factory can say if
- **| a port can be opened by this factory. Presumably an app maintains chains
- **| of factories for different suites, and asks each in turn about opening a
- **| a prospective file for reading (as a port) or writing (as a store). I'm
- **| not ready to tackle issues of format fidelity and factory chain ordering.
- **|
- **|| stores: a store is a mutable interface to a specific database file, and
- **| includes the port interface plus any methods particular to writing, which
- **| are few in number. Presumably the set of files that can be opened as
- **| stores is a subset of the set of files that can be opened as ports. A
- **| new store can be created with CreateNewFileStore() by supplying a new
- **| file name which does not yet exist (callers are always responsible for
- **| destroying any existing files before calling this method).
- |*/
-
- #define NS_IMDBFACTORY_IID_STR "2b80395c-b91e-4990-b1a7-023e99ab14e9"
-
- #define NS_IMDBFACTORY_IID \
- {0xf04aa4ab, 0x1fe, 0x4115, \
- { 0xa4, 0xa5, 0x68, 0x19, 0xdf, 0xf1, 0x10, 0x3d}}
-
-
- class nsIMdbFactory : public nsISupports { // suite entry points
- public:
-
- NS_DEFINE_STATIC_IID_ACCESSOR(NS_IMDBFACTORY_IID)
- // { ===== begin nsIMdbFactory methods =====
-
- // { ----- begin file methods -----
- NS_IMETHOD OpenOldFile(nsIMdbEnv* ev, nsIMdbHeap* ioHeap,
- const char* inFilePath,
- mdb_bool inFrozen, nsIMdbFile** acqFile) = 0;
- // Choose some subclass of nsIMdbFile to instantiate, in order to read
- // (and write if not frozen) the file known by inFilePath. The file
- // returned should be open and ready for use, and presumably positioned
- // at the first byte position of the file. The exact manner in which
- // files must be opened is considered a subclass specific detail, and
- // other portions or Mork source code don't want to know how it's done.
-
- NS_IMETHOD CreateNewFile(nsIMdbEnv* ev, nsIMdbHeap* ioHeap,
- const char* inFilePath,
- nsIMdbFile** acqFile) = 0;
- // Choose some subclass of nsIMdbFile to instantiate, in order to read
- // (and write if not frozen) the file known by inFilePath. The file
- // returned should be created and ready for use, and presumably positioned
- // at the first byte position of the file. The exact manner in which
- // files must be opened is considered a subclass specific detail, and
- // other portions or Mork source code don't want to know how it's done.
- // } ----- end file methods -----
-
- // { ----- begin env methods -----
- NS_IMETHOD MakeEnv(nsIMdbHeap* ioHeap, nsIMdbEnv** acqEnv) = 0; // acquire new env
- // ioHeap can be nil, causing a MakeHeap() style heap instance to be used
- // } ----- end env methods -----
-
- // { ----- begin heap methods -----
- NS_IMETHOD MakeHeap(nsIMdbEnv* ev, nsIMdbHeap** acqHeap) = 0; // acquire new heap
- // } ----- end heap methods -----
-
- // { ----- begin compare methods -----
- NS_IMETHOD MakeCompare(nsIMdbEnv* ev, nsIMdbCompare** acqCompare) = 0; // ASCII
- // } ----- end compare methods -----
-
- // { ----- begin row methods -----
- NS_IMETHOD MakeRow(nsIMdbEnv* ev, nsIMdbHeap* ioHeap, nsIMdbRow** acqRow) = 0; // new row
- // ioHeap can be nil, causing the heap associated with ev to be used
- // } ----- end row methods -----
-
- // { ----- begin port methods -----
- NS_IMETHOD CanOpenFilePort(
- nsIMdbEnv* ev, // context
- // const char* inFilePath, // the file to investigate
- // const mdbYarn* inFirst512Bytes,
- nsIMdbFile* ioFile, // db abstract file interface
- mdb_bool* outCanOpen, // whether OpenFilePort() might succeed
- mdbYarn* outFormatVersion) = 0; // informal file format description
-
- NS_IMETHOD OpenFilePort(
- nsIMdbEnv* ev, // context
- nsIMdbHeap* ioHeap, // can be nil to cause ev's heap attribute to be used
- // const char* inFilePath, // the file to open for readonly import
- nsIMdbFile* ioFile, // db abstract file interface
- const mdbOpenPolicy* inOpenPolicy, // runtime policies for using db
- nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental port open
- // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
- // then call nsIMdbFactory::ThumbToOpenPort() to get the port instance.
-
- NS_IMETHOD ThumbToOpenPort( // redeeming a completed thumb from OpenFilePort()
- nsIMdbEnv* ev, // context
- nsIMdbThumb* ioThumb, // thumb from OpenFilePort() with done status
- nsIMdbPort** acqPort) = 0; // acquire new port object
- // } ----- end port methods -----
-
- // { ----- begin store methods -----
- NS_IMETHOD CanOpenFileStore(
- nsIMdbEnv* ev, // context
- // const char* inFilePath, // the file to investigate
- // const mdbYarn* inFirst512Bytes,
- nsIMdbFile* ioFile, // db abstract file interface
- mdb_bool* outCanOpenAsStore, // whether OpenFileStore() might succeed
- mdb_bool* outCanOpenAsPort, // whether OpenFilePort() might succeed
- mdbYarn* outFormatVersion) = 0; // informal file format description
-
- NS_IMETHOD OpenFileStore( // open an existing database
- nsIMdbEnv* ev, // context
- nsIMdbHeap* ioHeap, // can be nil to cause ev's heap attribute to be used
- // const char* inFilePath, // the file to open for general db usage
- nsIMdbFile* ioFile, // db abstract file interface
- const mdbOpenPolicy* inOpenPolicy, // runtime policies for using db
- nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental store open
- // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
- // then call nsIMdbFactory::ThumbToOpenStore() to get the store instance.
-
- NS_IMETHOD
- ThumbToOpenStore( // redeem completed thumb from OpenFileStore()
- nsIMdbEnv* ev, // context
- nsIMdbThumb* ioThumb, // thumb from OpenFileStore() with done status
- nsIMdbStore** acqStore) = 0; // acquire new db store object
-
- NS_IMETHOD CreateNewFileStore( // create a new db with minimal content
- nsIMdbEnv* ev, // context
- nsIMdbHeap* ioHeap, // can be nil to cause ev's heap attribute to be used
- // const char* inFilePath, // name of file which should not yet exist
- nsIMdbFile* ioFile, // db abstract file interface
- const mdbOpenPolicy* inOpenPolicy, // runtime policies for using db
- nsIMdbStore** acqStore) = 0; // acquire new db store object
- // } ----- end store methods -----
-
- // } ===== end nsIMdbFactory methods =====
- };
-
- extern "C" nsIMdbFactory* MakeMdbFactory();
-
- /*| nsIMdbFile: abstract file interface resembling the original morkFile
- **| abstract interface (which was in turn modeled on the file interface
- **| from public domain IronDoc). The design of this file interface is
- **| complicated by the fact that some DB's will not find this interface
- **| adequate for all runtime requirements (even though this file API is
- **| enough to implement text-based DB's like Mork). For this reason,
- **| more methods have been added to let a DB library force the file to
- **| become closed so the DB can reopen the file in some other manner.
- **| Folks are encouraged to suggest ways to tune this interface to suit
- **| DB's that cannot manage to pull their maneuvers even given this API.
- **|
- **|| Tell: get the current i/o position in file
- **|
- **|| Seek: change the current i/o position in file
- **|
- **|| Eof: return file's total length in bytes
- **|
- **|| Read: input inSize bytes into outBuf, returning actual transfer size
- **|
- **|| Get: read starting at specific file offset (e.g. Seek(); Read();)
- **|
- **|| Write: output inSize bytes from inBuf, returning actual transfer size
- **|
- **|| Put: write starting at specific file offset (e.g. Seek(); Write();)
- **|
- **|| Flush: if written bytes are buffered, push them to final destination
- **|
- **|| Path: get file path in some string representation. This is intended
- **| either to support the display of file name in a user presentation, or
- **| to support the closing and reopening of the file when the DB needs more
- **| exotic file access than is presented by the nsIMdbFile interface.
- **|
- **|| Steal: tell this file to close any associated i/o stream in the file
- **| system, because the file ioThief intends to reopen the file in order
- **| to provide the MDB implementation with more exotic file access than is
- **| offered by the nsIMdbFile alone. Presumably the thief knows enough
- **| from Path() in order to know which file to reopen. If Steal() is
- **| successful, this file should probably delegate all future calls to
- **| the nsIMdbFile interface down to the thief files, so that even after
- **| the file has been stolen, it can still be read, written, or forcibly
- **| closed (by a call to CloseMdbObject()).
- **|
- **|| Thief: acquire and return thief passed to an earlier call to Steal().
- |*/
-
- #define NS_IMDBFILE_IID_STR "f04aa4ab-1fe7-4115-a4a5-6819dff1103d"
-
- #define NS_IMDBFILE_IID \
- {0xf04aa4ab, 0x1fe, 0x4115, \
- { 0xa4, 0xa5, 0x68, 0x19, 0xdf, 0xf1, 0x10, 0x3d}}
-
- class nsIMdbFile : public nsISupports { // minimal file interface
- public:
-
- NS_DEFINE_STATIC_IID_ACCESSOR(NS_IMDBFILE_IID)
- // { ===== begin nsIMdbFile methods =====
-
- // { ----- begin pos methods -----
- NS_IMETHOD Tell(nsIMdbEnv* ev, mdb_pos* outPos) const = 0;
- NS_IMETHOD Seek(nsIMdbEnv* ev, mdb_pos inPos, mdb_pos *outPos) = 0;
- NS_IMETHOD Eof(nsIMdbEnv* ev, mdb_pos* outPos) = 0;
- // } ----- end pos methods -----
-
- // { ----- begin read methods -----
- NS_IMETHOD Read(nsIMdbEnv* ev, void* outBuf, mdb_size inSize,
- mdb_size* outActualSize) = 0;
- NS_IMETHOD Get(nsIMdbEnv* ev, void* outBuf, mdb_size inSize,
- mdb_pos inPos, mdb_size* outActualSize) = 0;
- // } ----- end read methods -----
-
- // { ----- begin write methods -----
- NS_IMETHOD Write(nsIMdbEnv* ev, const void* inBuf, mdb_size inSize,
- mdb_size* outActualSize) = 0;
- NS_IMETHOD Put(nsIMdbEnv* ev, const void* inBuf, mdb_size inSize,
- mdb_pos inPos, mdb_size* outActualSize) = 0;
- NS_IMETHOD Flush(nsIMdbEnv* ev) = 0;
- // } ----- end attribute methods -----
-
- // { ----- begin path methods -----
- NS_IMETHOD Path(nsIMdbEnv* ev, mdbYarn* outFilePath) = 0;
- // } ----- end path methods -----
-
- // { ----- begin replacement methods -----
- NS_IMETHOD Steal(nsIMdbEnv* ev, nsIMdbFile* ioThief) = 0;
- NS_IMETHOD Thief(nsIMdbEnv* ev, nsIMdbFile** acqThief) = 0;
- // } ----- end replacement methods -----
-
- // { ----- begin versioning methods -----
- NS_IMETHOD BecomeTrunk(nsIMdbEnv* ev) = 0;
- // If this file is a file version branch created by calling AcquireBud(),
- // BecomeTrunk() causes this file's content to replace the original
- // file's content, typically by assuming the original file's identity.
- // This default implementation of BecomeTrunk() does nothing, and this
- // is appropriate behavior for files which are not branches, and is
- // also the right behavior for files returned from AcquireBud() which are
- // in fact the original file that has been truncated down to zero length.
-
- NS_IMETHOD AcquireBud(nsIMdbEnv* ev, nsIMdbHeap* ioHeap,
- nsIMdbFile** acqBud) = 0; // acquired file for new version of content
- // AcquireBud() starts a new "branch" version of the file, empty of content,
- // so that a new version of the file can be written. This new file
- // can later be told to BecomeTrunk() the original file, so the branch
- // created by budding the file will replace the original file. Some
- // file subclasses might initially take the unsafe but expedient
- // approach of simply truncating this file down to zero length, and
- // then returning the same morkFile pointer as this, with an extra
- // reference count increment. Note that the caller of AcquireBud() is
- // expected to eventually call CutStrongRef() on the returned file
- // in order to release the strong reference. High quality versions
- // of morkFile subclasses will create entirely new files which later
- // are renamed to become the old file, so that better transactional
- // behavior is exhibited by the file, so crashes protect old files.
- // Note that AcquireBud() is an illegal operation on readonly files.
- // } ----- end versioning methods -----
-
- // } ===== end nsIMdbFile methods =====
- };
-
- /*| nsIMdbPort: a readonly interface to a specific database file. The mutable
- **| nsIMdbStore interface is a subclass that includes writing behavior, but
- **| most of the needed db methods appear in the readonly nsIMdbPort interface.
- **|
- **|| mdbYarn: note all nsIMdbPort and nsIMdbStore subclasses must guarantee null
- **| termination of all strings written into mdbYarn instances, as long as
- **| mYarn_Size and mYarn_Buf are nonzero. Even truncated string values must
- **| be null terminated. This is more strict behavior than mdbYarn requires,
- **| but it is part of the nsIMdbPort and nsIMdbStore interface.
- **|
- **|| attributes: methods are provided to distinguish a readonly port from a
- **| mutable store, and whether a mutable store actually has any dirty content.
- **|
- **|| filepath: the file path used to open the port from the nsIMdbFactory can be
- **| queried and discovered by GetPortFilePath(), which includes format info.
- **|
- **|| export: a port can write itself in other formats, with perhaps a typical
- **| emphasis on text interchange formats used by other systems. A port can be
- **| queried to determine its preferred export interchange format, and a port
- **| can be queried to see whether a specific export format is supported. And
- **| actually exporting a port requires a new destination file name and format.
- **|
- **|| tokens: a port supports queries about atomized strings to map tokens to
- **| strings or strings to token integers. (All atomized strings must be in
- **| US-ASCII iso-8859-1 Latin1 charset encoding.) When a port is actually a
- **| mutable store and a string has not yet been atomized, then StringToToken()
- **| will actually do so and modify the store. The QueryToken() method will not
- **| atomize a string if it has not already been atomized yet, even in stores.
- **|
- **|| tables: other than string tokens, all port content is presented through
- **| tables, which are ordered collections of rows. Tables are identified by
- **| row scope and table kind, which might or might not be unique in a port,
- **| depending on app convention. When tables are effectively unique, then
- **| queries for specific scope and kind pairs will find those tables. To see
- **| all tables that match specific row scope and table kind patterns, even in
- **| the presence of duplicates, every port supports a GetPortTableCursor()
- **| method that returns an iterator over all matching tables. Table kind is
- **| considered scoped inside row scope, so passing a zero for table kind will
- **| find all table kinds for some nonzero row scope. Passing a zero for row
- **| scope will iterate over all tables in the port, in some undefined order.
- **| (A new table can be added to a port using nsIMdbStore::NewTable(), even when
- **| the requested scope and kind combination is already used by other tables.)
- **|
- **|| memory: callers can request that a database use less memory footprint in
- **| several flavors, from an inconsequential idle flavor to a rather drastic
- **| panic flavor. Callers might perform an idle purge very frequently if desired
- **| with very little cost, since only normally scheduled memory management will
- **| be conducted, such as freeing resources for objects scheduled to be dropped.
- **| Callers should perform session memory purges infrequently because they might
- **| involve costly scanning of data structures to removed cached content, and
- **| session purges are recommended only when a caller experiences memory crunch.
- **| Callers should only rarely perform a panic purge, in response to dire memory
- **| straits, since this is likely to make db operations much more expensive
- **| than they would be otherwise. A panic purge asks a database to free as much
- **| memory as possible while staying effective and operational, because a caller
- **| thinks application failure might otherwise occur. (Apps might better close
- **| an open db, so panic purges only make sense when a db is urgently needed.)
- |*/
- class nsIMdbPort : public nsISupports {
- public:
-
- // { ===== begin nsIMdbPort methods =====
-
- // { ----- begin attribute methods -----
- NS_IMETHOD GetIsPortReadonly(nsIMdbEnv* ev, mdb_bool* outBool) = 0;
- NS_IMETHOD GetIsStore(nsIMdbEnv* ev, mdb_bool* outBool) = 0;
- NS_IMETHOD GetIsStoreAndDirty(nsIMdbEnv* ev, mdb_bool* outBool) = 0;
-
- NS_IMETHOD GetUsagePolicy(nsIMdbEnv* ev,
- mdbUsagePolicy* ioUsagePolicy) = 0;
-
- NS_IMETHOD SetUsagePolicy(nsIMdbEnv* ev,
- const mdbUsagePolicy* inUsagePolicy) = 0;
- // } ----- end attribute methods -----
-
- // { ----- begin memory policy methods -----
- NS_IMETHOD IdleMemoryPurge( // do memory management already scheduled
- nsIMdbEnv* ev, // context
- mdb_size* outEstimatedBytesFreed) = 0; // approximate bytes actually freed
-
- NS_IMETHOD SessionMemoryPurge( // request specific footprint decrease
- nsIMdbEnv* ev, // context
- mdb_size inDesiredBytesFreed, // approximate number of bytes wanted
- mdb_size* outEstimatedBytesFreed) = 0; // approximate bytes actually freed
-
- NS_IMETHOD PanicMemoryPurge( // desperately free all possible memory
- nsIMdbEnv* ev, // context
- mdb_size* outEstimatedBytesFreed) = 0; // approximate bytes actually freed
- // } ----- end memory policy methods -----
-
- // { ----- begin filepath methods -----
- NS_IMETHOD GetPortFilePath(
- nsIMdbEnv* ev, // context
- mdbYarn* outFilePath, // name of file holding port content
- mdbYarn* outFormatVersion) = 0; // file format description
-
- NS_IMETHOD GetPortFile(
- nsIMdbEnv* ev, // context
- nsIMdbFile** acqFile) = 0; // acquire file used by port or store
- // } ----- end filepath methods -----
-
- // { ----- begin export methods -----
- NS_IMETHOD BestExportFormat( // determine preferred export format
- nsIMdbEnv* ev, // context
- mdbYarn* outFormatVersion) = 0; // file format description
-
- // some tentative suggested import/export formats
- // "ns:msg:db:port:format:ldif:ns4.0:passthrough" // necessary
- // "ns:msg:db:port:format:ldif:ns4.5:utf8" // necessary
- // "ns:msg:db:port:format:ldif:ns4.5:tabbed"
- // "ns:msg:db:port:format:ldif:ns4.5:binary" // necessary
- // "ns:msg:db:port:format:html:ns3.0:addressbook" // necessary
- // "ns:msg:db:port:format:html:display:verbose"
- // "ns:msg:db:port:format:html:display:concise"
- // "ns:msg:db:port:format:mork:zany:verbose" // necessary
- // "ns:msg:db:port:format:mork:zany:atomized" // necessary
- // "ns:msg:db:port:format:rdf:xml"
- // "ns:msg:db:port:format:xml:mork"
- // "ns:msg:db:port:format:xml:display:verbose"
- // "ns:msg:db:port:format:xml:display:concise"
- // "ns:msg:db:port:format:xml:print:verbose" // recommended
- // "ns:msg:db:port:format:xml:print:concise"
-
- NS_IMETHOD
- CanExportToFormat( // can export content in given specific format?
- nsIMdbEnv* ev, // context
- const char* inFormatVersion, // file format description
- mdb_bool* outCanExport) = 0; // whether ExportSource() might succeed
-
- NS_IMETHOD ExportToFormat( // export content in given specific format
- nsIMdbEnv* ev, // context
- // const char* inFilePath, // the file to receive exported content
- nsIMdbFile* ioFile, // destination abstract file interface
- const char* inFormatVersion, // file format description
- nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental export
- // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
- // then the export will be finished.
-
- // } ----- end export methods -----
-
- // { ----- begin token methods -----
- NS_IMETHOD TokenToString( // return a string name for an integer token
- nsIMdbEnv* ev, // context
- mdb_token inToken, // token for inTokenName inside this port
- mdbYarn* outTokenName) = 0; // the type of table to access
-
- NS_IMETHOD StringToToken( // return an integer token for scope name
- nsIMdbEnv* ev, // context
- const char* inTokenName, // Latin1 string to tokenize if possible
- mdb_token* outToken) = 0; // token for inTokenName inside this port
-
- // String token zero is never used and never supported. If the port
- // is a mutable store, then StringToToken() to create a new
- // association of inTokenName with a new integer token if possible.
- // But a readonly port will return zero for an unknown scope name.
-
- NS_IMETHOD QueryToken( // like StringToToken(), but without adding
- nsIMdbEnv* ev, // context
- const char* inTokenName, // Latin1 string to tokenize if possible
- mdb_token* outToken) = 0; // token for inTokenName inside this port
-
- // QueryToken() will return a string token if one already exists,
- // but unlike StringToToken(), will not assign a new token if not
- // already in use.
-
- // } ----- end token methods -----
-
- // { ----- begin row methods -----
- NS_IMETHOD HasRow( // contains a row with the specified oid?
- nsIMdbEnv* ev, // context
- const mdbOid* inOid, // hypothetical row oid
- mdb_bool* outHasRow) = 0; // whether GetRow() might succeed
-
- NS_IMETHOD GetRowRefCount( // get number of tables that contain a row
- nsIMdbEnv* ev, // context
- const mdbOid* inOid, // hypothetical row oid
- mdb_count* outRefCount) = 0; // number of tables containing inRowKey
-
- NS_IMETHOD GetRow( // access one row with specific oid
- nsIMdbEnv* ev, // context
- const mdbOid* inOid, // hypothetical row oid
- nsIMdbRow** acqRow) = 0; // acquire specific row (or null)
-
- // NS_IMETHOD
- // GetPortRowCursor( // get cursor for all rows in specific scope
- // nsIMdbEnv* ev, // context
- // mdb_scope inRowScope, // row scope for row ids
- // nsIMdbPortRowCursor** acqCursor) = 0; // all such rows in the port
-
- NS_IMETHOD FindRow(nsIMdbEnv* ev, // search for row with matching cell
- mdb_scope inRowScope, // row scope for row ids
- mdb_column inColumn, // the column to search (and maintain an index)
- const mdbYarn* inTargetCellValue, // cell value for which to search
- mdbOid* outRowOid, // out row oid on match (or {0,-1} for no match)
- nsIMdbRow** acqRow) = 0; // acquire matching row (or nil for no match)
- // can be null if you only want the oid
- // FindRow() searches for one row that has a cell in column inColumn with
- // a contained value with the same form (i.e. charset) and is byte-wise
- // identical to the blob described by yarn inTargetCellValue. Both content
- // and form of the yarn must be an exact match to find a matching row.
- //
- // (In other words, both a yarn's blob bytes and form are significant. The
- // form is not expected to vary in columns used for identity anyway. This
- // is intended to make the cost of FindRow() cheaper for MDB implementors,
- // since any cell value atomization performed internally must necessarily
- // make yarn form significant in order to avoid data loss in atomization.)
- //
- // FindRow() can lazily create an index on attribute inColumn for all rows
- // with that attribute in row space scope inRowScope, so that subsequent
- // calls to FindRow() will perform faster. Such an index might or might
- // not be persistent (but this seems desirable if it is cheap to do so).
- // Note that lazy index creation in readonly DBs is not very feasible.
- //
- // This FindRow() interface assumes that attribute inColumn is effectively
- // an alternative means of unique identification for a row in a rowspace,
- // so correct behavior is only guaranteed when no duplicates for this col
- // appear in the given set of rows. (If more than one row has the same cell
- // value in this column, no more than one will be found; and cutting one of
- // two duplicate rows can cause the index to assume no other such row lives
- // in the row space, so future calls return nil for negative search results
- // even though some duplicate row might still live within the rowspace.)
- //
- // In other words, the FindRow() implementation is allowed to assume simple
- // hash tables mapping unqiue column keys to associated row values will be
- // sufficient, where any duplication is not recorded because only one copy
- // of a given key need be remembered. Implementors are not required to sort
- // all rows by the specified column.
- // } ----- end row methods -----
-
- // { ----- begin table methods -----
- NS_IMETHOD HasTable( // supports a table with the specified oid?
- nsIMdbEnv* ev, // context
- const mdbOid* inOid, // hypothetical table oid
- mdb_bool* outHasTable) = 0; // whether GetTable() might succeed
-
- NS_IMETHOD GetTable( // access one table with specific oid
- nsIMdbEnv* ev, // context
- const mdbOid* inOid, // hypothetical table oid
- nsIMdbTable** acqTable) = 0; // acquire specific table (or null)
-
- NS_IMETHOD HasTableKind( // supports a table of the specified type?
- nsIMdbEnv* ev, // context
- mdb_scope inRowScope, // rid scope for row ids
- mdb_kind inTableKind, // the type of table to access
- mdb_count* outTableCount, // current number of such tables
- mdb_bool* outSupportsTable) = 0; // whether GetTableKind() might succeed
-
- // row scopes to be supported include the following suggestions:
- // "ns:msg:db:row:scope:address:cards:all"
- // "ns:msg:db:row:scope:mail:messages:all"
- // "ns:msg:db:row:scope:news:articles:all"
-
- // table kinds to be supported include the following suggestions:
- // "ns:msg:db:table:kind:address:cards:main"
- // "ns:msg:db:table:kind:address:lists:all"
- // "ns:msg:db:table:kind:address:list"
- // "ns:msg:db:table:kind:news:threads:all"
- // "ns:msg:db:table:kind:news:thread"
- // "ns:msg:db:table:kind:mail:threads:all"
- // "ns:msg:db:table:kind:mail:thread"
-
- NS_IMETHOD GetTableKind( // access one (random) table of specific type
- nsIMdbEnv* ev, // context
- mdb_scope inRowScope, // row scope for row ids
- mdb_kind inTableKind, // the type of table to access
- mdb_count* outTableCount, // current number of such tables
- mdb_bool* outMustBeUnique, // whether port can hold only one of these
- nsIMdbTable** acqTable) = 0; // acquire scoped collection of rows
-
- NS_IMETHOD
- GetPortTableCursor( // get cursor for all tables of specific type
- nsIMdbEnv* ev, // context
- mdb_scope inRowScope, // row scope for row ids
- mdb_kind inTableKind, // the type of table to access
- nsIMdbPortTableCursor** acqCursor) = 0; // all such tables in the port
- // } ----- end table methods -----
-
-
- // { ----- begin commit methods -----
-
- NS_IMETHOD ShouldCompress( // store wastes at least inPercentWaste?
- nsIMdbEnv* ev, // context
- mdb_percent inPercentWaste, // 0..100 percent file size waste threshold
- mdb_percent* outActualWaste, // 0..100 percent of file actually wasted
- mdb_bool* outShould) = 0; // true when about inPercentWaste% is wasted
- // ShouldCompress() returns true if the store can determine that the file
- // will shrink by an estimated percentage of inPercentWaste% (or more) if
- // CompressCommit() is called, because that percentage of the file seems
- // to be recoverable free space. The granularity is only in terms of
- // percentage points, and any value over 100 is considered equal to 100.
- //
- // If a store only has an approximate idea how much space might be saved
- // during a compress, then a best guess should be made. For example, the
- // Mork implementation might keep track of how much file space began with
- // text content before the first updating transaction, and then consider
- // all content following the start of the first transaction as potentially
- // wasted space if it is all updates and not just new content. (This is
- // a safe assumption in the sense that behavior will stabilize on a low
- // estimate of wastage after a commit removes all transaction updates.)
- //
- // Some db formats might attempt to keep a very accurate reckoning of free
- // space size, so a very accurate determination can be made. But other db
- // formats might have difficulty determining size of free space, and might
- // require some lengthy calculation to answer. This is the reason for
- // passing in the percentage threshold of interest, so that such lengthy
- // computations can terminate early as soon as at least inPercentWaste is
- // found, so that the entire file need not be groveled when unnecessary.
- // However, we hope implementations will always favor fast but imprecise
- // heuristic answers instead of extremely slow but very precise answers.
- //
- // If the outActualWaste parameter is non-nil, it will be used to return
- // the actual estimated space wasted as a percentage of file size. (This
- // parameter is provided so callers need not call repeatedly with altered
- // inPercentWaste values to isolate the actual wastage figure.) Note the
- // actual wastage figure returned can exactly equal inPercentWaste even
- // when this grossly underestimates the real figure involved, if the db
- // finds it very expensive to determine the extent of wastage after it is
- // known to at least exceed inPercentWaste. Note we expect that whenever
- // outShould returns true, that outActualWaste returns >= inPercentWaste.
- //
- // The effect of different inPercentWaste values is not very uniform over
- // the permitted range. For example, 50 represents 50% wastage, or a file
- // that is about double what it should be ideally. But 99 represents 99%
- // wastage, or a file that is about ninety-nine times as big as it should
- // be ideally. In the smaller direction, 25 represents 25% wastage, or
- // a file that is only 33% larger than it should be ideally.
- //
- // Callers can determine what policy they want to use for considering when
- // a file holds too much wasted space, and express this as a percentage
- // of total file size to pass as in the inPercentWaste parameter. A zero
- // likely returns always trivially true, and 100 always trivially false.
- // The great majority of callers are expected to use values from 25 to 75,
- // since most plausible thresholds for compressing might fall between the
- // extremes of 133% of ideal size and 400% of ideal size. (Presumably the
- // larger a file gets, the more important the percentage waste involved, so
- // a sliding scale for compress thresholds might use smaller numbers for
- // much bigger file sizes.)
-
- // } ----- end commit methods -----
-
- // } ===== end nsIMdbPort methods =====
- };
-
- /*| nsIMdbStore: a mutable interface to a specific database file.
- **|
- **|| tables: one can force a new table to exist in a store with NewTable()
- **| and nonzero values for both row scope and table kind. (If one wishes only
- **| one table of a certain kind, then one might look for it first using the
- **| GetTableKind() method). One can pass inMustBeUnique to force future
- **| users of this store to be unable to create other tables with the same pair
- **| of scope and kind attributes. When inMustBeUnique is true, and the table
- **| with the given scope and kind pair already exists, then the existing one
- **| is returned instead of making a new table. Similarly, if one passes false
- **| for inMustBeUnique, but the table kind has already been marked unique by a
- **| previous user of the store, then the existing unique table is returned.
- **|
- **|| import: all or some of another port's content can be imported by calling
- **| AddPortContent() with a row scope identifying the extent of content to
- **| be imported. A zero row scope will import everything. A nonzero row
- **| scope will only import tables with a matching row scope. Note that one
- **| must somehow find a way to negotiate possible conflicts between existing
- **| row content and imported row content, and this involves a specific kind of
- **| definition for row identity involving either row IDs or unique attributes,
- **| or some combination of these two. At the moment I am just going to wave
- **| my hands, and say the default behavior is to assign all new row identities
- **| to all imported content, which will result in no merging of content; this
- **| must change later because it is unacceptable in some contexts.
- **|
- **|| commits: to manage modifications in a mutable store, very few methods are
- **| really needed to indicate global policy choices that are independent of
- **| the actual modifications that happen in objects at the level of tables,
- **| rows, and cells, etc. The most important policy to specify is which sets
- **| of changes are considered associated in a manner such that they should be
- **| applied together atomically to a given store. We call each such group of
- **| changes a transaction. We handle three different grades of transaction,
- **| but they differ only in semantic significance to the application, and are
- **| not intended to nest. (If small transactions were nested inside large
- **| transactions, that would imply that a single large transaction must be
- **| atomic over all the contained small transactions; but actually we intend
- **| smalls transaction never be undone once commited due to, say, aborting a
- **| transaction of greater significance.) The small, large, and session level
- **| commits have equal granularity, and differ only in risk of loss from the
- **| perspective of an application. Small commits characterize changes that
- **| can be lost with relatively small risk, so small transactions can delay
- **| until later if they are expensive or impractical to commit. Large commits
- **| involve changes that would probably inconvenience users if lost, so the
- **| need to pay costs of writing is rather greater than with small commits.
- **| Session commits are last ditch attempts to save outstanding changes before
- **| stopping the use of a particular database, so there will be no later point
- **| in time to save changes that have been delayed due to possible high cost.
- **| If large commits are never delayed, then a session commit has about the
- **| same performance effect as another large commit; but if small and large
- **| commits are always delayed, then a session commit is likely to be rather
- **| expensive as a runtime cost compared to any earlier database usage.
- **|
- **|| aborts: the only way to abort changes to a store is by closing the store.
- **| So there is no specific method for causing any abort. Stores must discard
- **| all changes made that are uncommited when a store is closed. This design
- **| choice makes the implementations of tables, rows, and cells much less
- **| complex because they need not maintain a record of undobable changes. When
- **| a store is closed, presumably this precipitates the closure of all tables,
- **| rows, and cells in the store as well. So an application can revert the
- **| state of a store in the user interface by quietly closing and reopening a
- **| store, because this will discard uncommited changes and show old content.
- **| This implies an app that closes a store will need to send a "scramble"
- **| event notification to any views that depend on old discarded content.
- |*/
-
- #define NS_IMDBSTORE_IID_STR "726618d3-f15b-49b9-9f4a-efcc9db53d0d"
-
- #define NS_IMDBSTORE_IID \
- {0x726618d3, 0xf15b, 0x49b9, \
- {0x9f, 0x4a, 0xef, 0xcc, 0x9d, 0xb5, 0x3d, 0x0d}}
-
- class nsIMdbStore : public nsIMdbPort {
- public:
- NS_DEFINE_STATIC_IID_ACCESSOR(NS_IMDBSTORE_IID)
-
- // { ===== begin nsIMdbStore methods =====
-
- // { ----- begin table methods -----
- NS_IMETHOD NewTable( // make one new table of specific type
- nsIMdbEnv* ev, // context
- mdb_scope inRowScope, // row scope for row ids
- mdb_kind inTableKind, // the type of table to access
- mdb_bool inMustBeUnique, // whether store can hold only one of these
- const mdbOid* inOptionalMetaRowOid, // can be nil to avoid specifying
- nsIMdbTable** acqTable) = 0; // acquire scoped collection of rows
-
- NS_IMETHOD NewTableWithOid( // make one new table of specific type
- nsIMdbEnv* ev, // context
- const mdbOid* inOid, // caller assigned oid
- mdb_kind inTableKind, // the type of table to access
- mdb_bool inMustBeUnique, // whether store can hold only one of these
- const mdbOid* inOptionalMetaRowOid, // can be nil to avoid specifying
- nsIMdbTable** acqTable) = 0; // acquire scoped collection of rows
- // } ----- end table methods -----
-
- // { ----- begin row scope methods -----
- NS_IMETHOD RowScopeHasAssignedIds(nsIMdbEnv* ev,
- mdb_scope inRowScope, // row scope for row ids
- mdb_bool* outCallerAssigned, // nonzero if caller assigned specified
- mdb_bool* outStoreAssigned) = 0; // nonzero if store db assigned specified
-
- NS_IMETHOD SetCallerAssignedIds(nsIMdbEnv* ev,
- mdb_scope inRowScope, // row scope for row ids
- mdb_bool* outCallerAssigned, // nonzero if caller assigned specified
- mdb_bool* outStoreAssigned) = 0; // nonzero if store db assigned specified
-
- NS_IMETHOD SetStoreAssignedIds(nsIMdbEnv* ev,
- mdb_scope inRowScope, // row scope for row ids
- mdb_bool* outCallerAssigned, // nonzero if caller assigned specified
- mdb_bool* outStoreAssigned) = 0; // nonzero if store db assigned specified
- // } ----- end row scope methods -----
-
- // { ----- begin row methods -----
- NS_IMETHOD NewRowWithOid(nsIMdbEnv* ev, // new row w/ caller assigned oid
- const mdbOid* inOid, // caller assigned oid
- nsIMdbRow** acqRow) = 0; // create new row
-
- NS_IMETHOD NewRow(nsIMdbEnv* ev, // new row with db assigned oid
- mdb_scope inRowScope, // row scope for row ids
- nsIMdbRow** acqRow) = 0; // create new row
- // Note this row must be added to some table or cell child before the
- // store is closed in order to make this row persist across sesssions.
-
- // } ----- end row methods -----
-
- // { ----- begin inport/export methods -----
- NS_IMETHOD ImportContent( // import content from port
- nsIMdbEnv* ev, // context
- mdb_scope inRowScope, // scope for rows (or zero for all?)
- nsIMdbPort* ioPort, // the port with content to add to store
- nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental import
- // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
- // then the import will be finished.
-
- NS_IMETHOD ImportFile( // import content from port
- nsIMdbEnv* ev, // context
- nsIMdbFile* ioFile, // the file with content to add to store
- nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental import
- // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
- // then the import will be finished.
- // } ----- end inport/export methods -----
-
- // { ----- begin hinting methods -----
- NS_IMETHOD
- ShareAtomColumnsHint( // advise re shared column content atomizing
- nsIMdbEnv* ev, // context
- mdb_scope inScopeHint, // zero, or suggested shared namespace
- const mdbColumnSet* inColumnSet) = 0; // cols desired tokenized together
-
- NS_IMETHOD
- AvoidAtomColumnsHint( // advise column with poor atomizing prospects
- nsIMdbEnv* ev, // context
- const mdbColumnSet* inColumnSet) = 0; // cols with poor atomizing prospects
- // } ----- end hinting methods -----
-
- // { ----- begin commit methods -----
- NS_IMETHOD SmallCommit( // save minor changes if convenient and uncostly
- nsIMdbEnv* ev) = 0; // context
-
- NS_IMETHOD LargeCommit( // save important changes if at all possible
- nsIMdbEnv* ev, // context
- nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental commit
- // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
- // then the commit will be finished. Note the store is effectively write
- // locked until commit is finished or canceled through the thumb instance.
- // Until the commit is done, the store will report it has readonly status.
-
- NS_IMETHOD SessionCommit( // save all changes if large commits delayed
- nsIMdbEnv* ev, // context
- nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental commit
- // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
- // then the commit will be finished. Note the store is effectively write
- // locked until commit is finished or canceled through the thumb instance.
- // Until the commit is done, the store will report it has readonly status.
-
- NS_IMETHOD
- CompressCommit( // commit and make db physically smaller if possible
- nsIMdbEnv* ev, // context
- nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental commit
- // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
- // then the commit will be finished. Note the store is effectively write
- // locked until commit is finished or canceled through the thumb instance.
- // Until the commit is done, the store will report it has readonly status.
-
- // } ----- end commit methods -----
-
- // } ===== end nsIMdbStore methods =====
- };
-
- /*| nsIMdbCursor: base cursor class for iterating row cells and table rows
- **|
- **|| count: the number of elements in the collection (table or row)
- **|
- **|| seed: the change count in the underlying collection, which is synced
- **| with the collection when the iteration position is set, and henceforth
- **| acts to show whether the iter has lost collection synchronization, in
- **| case it matters to clients whether any change happens during iteration.
- **|
- **|| pos: the position of the current element in the collection. Negative
- **| means a position logically before the first element. A positive value
- **| equal to count (or larger) implies a position after the last element.
- **| To iterate over all elements, set the position to negative, so subsequent
- **| calls to any 'next' method will access the first collection element.
- **|
- **|| doFailOnSeedOutOfSync: whether a cursor should return an error if the
- **| cursor's snapshot of a table's seed becomes stale with respect the table's
- **| current seed value (which implies the iteration is less than total) in
- **| between to cursor calls that actually access collection content. By
- **| default, a cursor should assume this attribute is false until specified,
- **| so that iterations quietly try to re-sync when they loose coherence.
- |*/
-
- #define NS_IMDBCURSOR_IID_STR "a0c37337-6ebc-474c-90db-e65ea0b850aa"
-
- #define NS_IMDBCURSOR_IID \
- {0xa0c37337, 0x6ebc, 0x474c, \
- {0x90, 0xdb, 0xe6, 0x5e, 0xa0, 0xb8, 0x50, 0xaa}}
-
- class nsIMdbCursor : public nsISupports { // collection iterator
- public:
-
- NS_DEFINE_STATIC_IID_ACCESSOR(NS_IMDBCURSOR_IID)
- // { ===== begin nsIMdbCursor methods =====
-
- // { ----- begin attribute methods -----
- NS_IMETHOD GetCount(nsIMdbEnv* ev, mdb_count* outCount) = 0; // readonly
- NS_IMETHOD GetSeed(nsIMdbEnv* ev, mdb_seed* outSeed) = 0; // readonly
-
- NS_IMETHOD SetPos(nsIMdbEnv* ev, mdb_pos inPos) = 0; // mutable
- NS_IMETHOD GetPos(nsIMdbEnv* ev, mdb_pos* outPos) = 0;
-
- NS_IMETHOD SetDoFailOnSeedOutOfSync(nsIMdbEnv* ev, mdb_bool inFail) = 0;
- NS_IMETHOD GetDoFailOnSeedOutOfSync(nsIMdbEnv* ev, mdb_bool* outFail) = 0;
- // } ----- end attribute methods -----
-
- // } ===== end nsIMdbCursor methods =====
- };
-
- #define NS_IMDBPORTTABLECURSOR_IID_STR = "f181a41e-933d-49b3-af93-20d3634b8b78"
-
- #define NS_IMDBPORTTABLECURSOR_IID \
- {0xf181a41e, 0x933d, 0x49b3, \
- {0xaf, 0x93, 0x20, 0xd3, 0x63, 0x4b, 0x8b, 0x78}}
-
- /*| nsIMdbPortTableCursor: cursor class for iterating port tables
- **|
- **|| port: the cursor is associated with a specific port, which can be
- **| set to a different port (which resets the position to -1 so the
- **| next table acquired is the first in the port.
- **|
- |*/
- class nsIMdbPortTableCursor : public nsISupports { // table collection iterator
- public:
-
- NS_DEFINE_STATIC_IID_ACCESSOR(NS_IMDBPORTTABLECURSOR_IID)
- // { ===== begin nsIMdbPortTableCursor methods =====
-
- // { ----- begin attribute methods -----
- NS_IMETHOD SetPort(nsIMdbEnv* ev, nsIMdbPort* ioPort) = 0; // sets pos to -1
- NS_IMETHOD GetPort(nsIMdbEnv* ev, nsIMdbPort** acqPort) = 0;
-
- NS_IMETHOD SetRowScope(nsIMdbEnv* ev, // sets pos to -1
- mdb_scope inRowScope) = 0;
- NS_IMETHOD GetRowScope(nsIMdbEnv* ev, mdb_scope* outRowScope) = 0;
- // setting row scope to zero iterates over all row scopes in port
-
- NS_IMETHOD SetTableKind(nsIMdbEnv* ev, // sets pos to -1
- mdb_kind inTableKind) = 0;
- NS_IMETHOD GetTableKind(nsIMdbEnv* ev, mdb_kind* outTableKind) = 0;
- // setting table kind to zero iterates over all table kinds in row scope
- // } ----- end attribute methods -----
-
- // { ----- begin table iteration methods -----
- NS_IMETHOD NextTable( // get table at next position in the db
- nsIMdbEnv* ev, // context
- nsIMdbTable** acqTable) = 0; // the next table in the iteration
- // } ----- end table iteration methods -----
-
- // } ===== end nsIMdbPortTableCursor methods =====
- };
-
- /*| nsIMdbCollection: an object that collects a set of other objects as members.
- **| The main purpose of this base class is to unify the perceived semantics
- **| of tables and rows where their collection behavior is similar. This helps
- **| isolate the mechanics of collection behavior from the other semantics that
- **| are more characteristic of rows and tables.
- **|
- **|| count: the number of objects in a collection is the member count. (Some
- **| collection interfaces call this attribute the 'size', but that can be a
- **| little ambiguous, and counting actual members is harder to confuse.)
- **|
- **|| seed: the seed of a collection is a counter for changes in membership in
- **| a specific collection. This seed should change when members are added to
- **| or removed from a collection, but not when a member changes internal state.
- **| The seed should also change whenever the internal collection of members has
- **| a complex state change that reorders member positions (say by sorting) that
- **| would affect the nature of an iteration over that collection of members.
- **| The purpose of a seed is to inform any outstanding collection cursors that
- **| they might be stale, without incurring the cost of broadcasting an event
- **| notification to such cursors, which would need more data structure support.
- **| Presumably a cursor in a particular mdb code suite has much more direct
- **| access to a collection seed member slot that this abstract COM interface,
- **| so this information is intended more for clients outside mdb that want to
- **| make inferences similar to those made by the collection cursors. The seed
- **| value as an integer magnitude is not very important, and callers should not
- **| assume meaningful information can be derived from an integer value beyond
- **| whether it is equal or different from a previous inspection. A seed uses
- **| integers of many bits in order to make the odds of wrapping and becoming
- **| equal to an earlier seed value have probability that is vanishingly small.
- **|
- **|| port: every collection is associated with a specific database instance.
- **|
- **|| cursor: a subclass of nsIMdbCursor suitable for this specific collection
- **| subclass. The ability to GetCursor() from the base nsIMdbCollection class
- **| is not really as useful as getting a more specifically typed cursor more
- **| directly from the base class without any casting involved. So including
- **| this method here is more for conceptual illustration.
- **|
- **|| oid: every collection has an identity that persists from session to
- **| session. Implementations are probably able to distinguish row IDs from
- **| table IDs, but we don't specify anything official in this regard. A
- **| collection has the same identity for the lifetime of the collection,
- **| unless identity is swapped with another collection by means of a call to
- **| BecomeContent(), which is considered a way to swap a new representation
- **| for an old well-known object. (Even so, only content appears to change,
- **| while the identity seems to stay the same.)
- **|
- **|| become: developers can effectively cause two objects to swap identities,
- **| in order to effect a complete swap between what persistent content is
- **| represented by two oids. The caller should consider this a content swap,
- **| and not identity wap, because identities will seem to stay the same while
- **| only content changes. However, implementations will likely do this
- **| internally by swapping identities. Callers must swap content only
- **| between objects of similar type, such as a row with another row, and a
- **| table with another table, because implementations need not support
- **| cross-object swapping because it might break object name spaces.
- **|
- **|| dropping: when a caller expects a row or table will no longer be used, the
- **| caller can tell the collection to 'drop activity', which means the runtime
- **| object can have it's internal representation purged to save memory or any
- **| other resource that is being consumed by the collection's representation.
- **| This has no effect on the collection's persistent content or semantics,
- **| and is only considered a runtime effect. After a collection drops
- **| activity, the object should still be as usable as before (because it has
- **| NOT been closed), but further usage can be expensive to re-instate because
- **| it might involve reallocating space and/or re-reading disk space. But
- **| since this future usage is not expected, the caller does not expect to
- **| pay the extra expense. An implementation can choose to implement
- **| 'dropping activity' in different ways, or even not at all if this
- **| operation is not really feasible. Callers cannot ask objects whether they
- **| are 'dropped' or not, so this should be transparent. (Note that
- **| implementors might fear callers do not really know whether future
- **| usage will occur, and therefore might delay the act of dropping until
- **| the near future, until seeing whether the object is used again
- **| immediately elsewhere. Such use soon after the drop request might cause
- **| the drop to be cancelled.)
- |*/
- class nsIMdbCollection : public nsISupports { // sequence of objects
- public:
-
- // { ===== begin nsIMdbCollection methods =====
-
- // { ----- begin attribute methods -----
- NS_IMETHOD GetSeed(nsIMdbEnv* ev,
- mdb_seed* outSeed) = 0; // member change count
- NS_IMETHOD GetCount(nsIMdbEnv* ev,
- mdb_count* outCount) = 0; // member count
-
- NS_IMETHOD GetPort(nsIMdbEnv* ev,
- nsIMdbPort** acqPort) = 0; // collection container
- // } ----- end attribute methods -----
-
- // { ----- begin cursor methods -----
- NS_IMETHOD GetCursor( // make a cursor starting iter at inMemberPos
- nsIMdbEnv* ev, // context
- mdb_pos inMemberPos, // zero-based ordinal pos of member in collection
- nsIMdbCursor** acqCursor) = 0; // acquire new cursor instance
- // } ----- end cursor methods -----
-
- // { ----- begin ID methods -----
- NS_IMETHOD GetOid(nsIMdbEnv* ev,
- mdbOid* outOid) = 0; // read object identity
- NS_IMETHOD BecomeContent(nsIMdbEnv* ev,
- const mdbOid* inOid) = 0; // exchange content
- // } ----- end ID methods -----
-
- // { ----- begin activity dropping methods -----
- NS_IMETHOD DropActivity( // tell collection usage no longer expected
- nsIMdbEnv* ev) = 0;
- // } ----- end activity dropping methods -----
-
- // } ===== end nsIMdbCollection methods =====
- };
-
- /*| nsIMdbTable: an ordered collection of rows
- **|
- **|| row scope: an integer token for an atomized string in this database
- **| that names a space for row IDs. This attribute of a table is intended
- **| as guidance metainformation that helps with searching a database for
- **| tables that operate on collections of rows of the specific type. By
- **| convention, a table with a specific row scope is expected to focus on
- **| containing rows that belong to that scope, however exceptions are easily
- **| allowed because all rows in a table are known by both row ID and scope.
- **| (A table with zero row scope is never allowed because this would make it
- **| ambiguous to use a zero row scope when iterating over tables in a port to
- **| indicate that all row scopes should be seen by a cursor.)
- **|
- **|| table kind: an integer token for an atomized string in this database
- **| that names a kind of table as a subset of the associated row scope. This
- **| attribute is intended as guidance metainformation to clarify the role of
- **| this table with respect to other tables in the same row scope, and this
- **| also helps search for such tables in a database. By convention, a table
- **| with a specific table kind has a consistent role for containing rows with
- **| respect to other collections of such rows in the same row scope. Also by
- **| convention, at least one table in a row scope has a table kind purporting
- **| to contain ALL the rows that belong in that row scope, so that at least
- **| one table exists that allows all rows in a scope to be interated over.
- **| (A table with zero table kind is never allowed because this would make it
- **| ambiguous to use a zero table kind when iterating over tables in a port to
- **| indicate that all table kinds in a row scope should be seen by a cursor.)
- **|
- **|| port: every table is considered part of some port that contains the
- **| table, so that closing the containing port will cause the table to be
- **| indirectly closed as well. We make it easy to get the containing port for
- **| a table, because the port supports important semantic interfaces that will
- **| affect how content in table is presented; the most important port context
- **| that affects a table is specified by the set of token to string mappings
- **| that affect all tokens used throughout the database, and which drive the
- **| meanings of row scope, table kind, cell columns, etc.
- **|
- **|| cursor: a cursor that iterates over the rows in this table, where rows
- **| have zero-based index positions from zero to count-1. Making a cursor
- **| with negative position will next iterate over the first row in the table.
- **|
- **|| position: given any position from zero to count-1, a table will return
- **| the row ID and row scope for the row at that position. (One can use the
- **| GetRowAllCells() method to read that row, or else use a row cursor to both
- **| get the row at some position and read its content at the same time.) The
- **| position depends on whether a table is sorted, and upon the actual sort.
- **| Note that moving a row's position is only possible in unsorted tables.
- **|
- **|| row set: every table contains a collection of rows, where a member row is
- **| referenced by the table using the row ID and row scope for the row. No
- **| single table owns a given row instance, because rows are effectively ref-
- **| counted and destroyed only when the last table removes a reference to that
- **| particular row. (But a row can be emptied of all content no matter how
- **| many refs exist, and this might be the next best thing to destruction.)
- **| Once a row exists in a least one table (after NewRow() is called), then it
- **| can be added to any other table by calling AddRow(), or removed from any
- **| table by calling CutRow(), or queried as a member by calling HasRow(). A
- **| row can only be added to a table once, and further additions do nothing and
- **| complain not at all. Cutting a row from a table only does something when
- **| the row was actually a member, and otherwise does nothing silently.
- **|
- **|| row ref count: one can query the number of tables (and/or cells)
- **| containing a row as a member or a child.
- **|
- **|| row content: one can access or modify the cell content in a table's row
- **| by moving content to or from an instance of nsIMdbRow. Note that nsIMdbRow
- **| never represents the actual row inside a table, and this is the reason
- **| why nsIMdbRow instances do not have row IDs or row scopes. So an instance
- **| of nsIMdbRow always and only contains a snapshot of some or all content in
- **| past, present, or future persistent row inside a table. This means that
- **| reading and writing rows in tables has strictly copy semantics, and we
- **| currently do not plan any exceptions for specific performance reasons.
- **|
- **|| sorting: note all rows are assumed sorted by row ID as a secondary
- **| sort following the primary column sort, when table rows are sorted.
- **|
- **|| indexes:
- |*/
-
-
- #define NS_IMDBTABLE_IID_STR = "fe11bc98-d02b-4128-9fac-87042fdf9639"
-
- #define NS_IMDBTABLE_IID \
- {0xfe11bc98, 0xd02b, 0x4128, \
- {0x9f, 0xac, 0x87, 0x04, 0x2f, 0xdf, 0x96, 0x39}}
-
-
- class nsIMdbTable : public nsIMdbCollection { // a collection of rows
- public:
-
- NS_DEFINE_STATIC_IID_ACCESSOR(NS_IMDBTABLE_IID)
- // { ===== begin nsIMdbTable methods =====
-
- // { ----- begin meta attribute methods -----
- NS_IMETHOD SetTablePriority(nsIMdbEnv* ev, mdb_priority inPrio) = 0;
- NS_IMETHOD GetTablePriority(nsIMdbEnv* ev, mdb_priority* outPrio) = 0;
-
- NS_IMETHOD GetTableBeVerbose(nsIMdbEnv* ev, mdb_bool* outBeVerbose) = 0;
- NS_IMETHOD SetTableBeVerbose(nsIMdbEnv* ev, mdb_bool inBeVerbose) = 0;
-
- NS_IMETHOD GetTableIsUnique(nsIMdbEnv* ev, mdb_bool* outIsUnique) = 0;
-
- NS_IMETHOD GetTableKind(nsIMdbEnv* ev, mdb_kind* outTableKind) = 0;
- NS_IMETHOD GetRowScope(nsIMdbEnv* ev, mdb_scope* outRowScope) = 0;
-
- NS_IMETHOD GetMetaRow(
- nsIMdbEnv* ev, // context
- const mdbOid* inOptionalMetaRowOid, // can be nil to avoid specifying
- mdbOid* outOid, // output meta row oid, can be nil to suppress output
- nsIMdbRow** acqRow) = 0; // acquire table's unique singleton meta row
- // The purpose of a meta row is to support the persistent recording of
- // meta info about a table as cells put into the distinguished meta row.
- // Each table has exactly one meta row, which is not considered a member
- // of the collection of rows inside the table. The only way to tell
- // whether a row is a meta row is by the fact that it is returned by this
- // GetMetaRow() method from some table. Otherwise nothing distinguishes
- // a meta row from any other row. A meta row can be used anyplace that
- // any other row can be used, and can even be put into other tables (or
- // the same table) as a table member, if this is useful for some reason.
- // The first attempt to access a table's meta row using GetMetaRow() will
- // cause the meta row to be created if it did not already exist. When the
- // meta row is created, it will have the row oid that was previously
- // requested for this table's meta row; or if no oid was ever explicitly
- // specified for this meta row, then a unique oid will be generated in
- // the row scope named "m" (so obviously MDB clients should not
- // manually allocate any row IDs from that special meta scope namespace).
- // The meta row oid can be specified either when the table is created, or
- // else the first time that GetMetaRow() is called, by passing a non-nil
- // pointer to an oid for parameter inOptionalMetaRowOid. The meta row's
- // actual oid is returned in outOid (if this is a non-nil pointer), and
- // it will be different from inOptionalMetaRowOid when the meta row was
- // already given a different oid earlier.
- // } ----- end meta attribute methods -----
-
-
- // { ----- begin cursor methods -----
- NS_IMETHOD GetTableRowCursor( // make a cursor, starting iteration at inRowPos
- nsIMdbEnv* ev, // context
- mdb_pos inRowPos, // zero-based ordinal position of row in table
- nsIMdbTableRowCursor** acqCursor) = 0; // acquire new cursor instance
- // } ----- end row position methods -----
-
- // { ----- begin row position methods -----
- NS_IMETHOD PosToOid( // get row member for a table position
- nsIMdbEnv* ev, // context
- mdb_pos inRowPos, // zero-based ordinal position of row in table
- mdbOid* outOid) = 0; // row oid at the specified position
-
- NS_IMETHOD OidToPos( // test for the table position of a row member
- nsIMdbEnv* ev, // context
- const mdbOid* inOid, // row to find in table
- mdb_pos* outPos) = 0; // zero-based ordinal position of row in table
-
- NS_IMETHOD PosToRow( // test for the table position of a row member
- nsIMdbEnv* ev, // context
- mdb_pos inRowPos, // zero-based ordinal position of row in table
- nsIMdbRow** acqRow) = 0; // acquire row at table position inRowPos
-
- NS_IMETHOD RowToPos( // test for the table position of a row member
- nsIMdbEnv* ev, // context
- nsIMdbRow* ioRow, // row to find in table
- mdb_pos* outPos) = 0; // zero-based ordinal position of row in table
- // } ----- end row position methods -----
-
- // { ----- begin oid set methods -----
- NS_IMETHOD AddOid( // make sure the row with inOid is a table member
- nsIMdbEnv* ev, // context
- const mdbOid* inOid) = 0; // row to ensure membership in table
-
- NS_IMETHOD HasOid( // test for the table position of a row member
- nsIMdbEnv* ev, // context
- const mdbOid* inOid, // row to find in table
- mdb_bool* outHasOid) = 0; // whether inOid is a member row
-
- NS_IMETHOD CutOid( // make sure the row with inOid is not a member
- nsIMdbEnv* ev, // context
- const mdbOid* inOid) = 0; // row to remove from table
- // } ----- end oid set methods -----
-
- // { ----- begin row set methods -----
- NS_IMETHOD NewRow( // create a new row instance in table
- nsIMdbEnv* ev, // context
- mdbOid* ioOid, // please use minus one (unbound) rowId for db-assigned IDs
- nsIMdbRow** acqRow) = 0; // create new row
-
- NS_IMETHOD AddRow( // make sure the row with inOid is a table member
- nsIMdbEnv* ev, // context
- nsIMdbRow* ioRow) = 0; // row to ensure membership in table
-
- NS_IMETHOD HasRow( // test for the table position of a row member
- nsIMdbEnv* ev, // context
- nsIMdbRow* ioRow, // row to find in table
- mdb_bool* outHasRow) = 0; // whether row is a table member
-
- NS_IMETHOD CutRow( // make sure the row with inOid is not a member
- nsIMdbEnv* ev, // context
- nsIMdbRow* ioRow) = 0; // row to remove from table
-
- NS_IMETHOD CutAllRows( // remove all rows from the table
- nsIMdbEnv* ev) = 0; // context
- // } ----- end row set methods -----
-
- // { ----- begin hinting methods -----
- NS_IMETHOD SearchColumnsHint( // advise re future expected search cols
- nsIMdbEnv* ev, // context
- const mdbColumnSet* inColumnSet) = 0; // columns likely to be searched
-
- NS_IMETHOD SortColumnsHint( // advise re future expected sort columns
- nsIMdbEnv* ev, // context
- const mdbColumnSet* inColumnSet) = 0; // columns for likely sort requests
-
- NS_IMETHOD StartBatchChangeHint( // advise before many adds and cuts
- nsIMdbEnv* ev, // context
- const void* inLabel) = 0; // intend unique address to match end call
- // If batch starts nest by virtue of nesting calls in the stack, then
- // the address of a local variable makes a good batch start label that
- // can be used at batch end time, and such addresses remain unique.
-
- NS_IMETHOD EndBatchChangeHint( // advise before many adds and cuts
- nsIMdbEnv* ev, // context
- const void* inLabel) = 0; // label matching start label
- // Suppose a table is maintaining one or many sort orders for a table,
- // so that every row added to the table must be inserted in each sort,
- // and every row cut must be removed from each sort. If a db client
- // intends to make many such changes before needing any information
- // about the order or positions of rows inside a table, then a client
- // might tell the table to start batch changes in order to disable
- // sorting of rows for the interim. Presumably a table will then do
- // a full sort of all rows at need when the batch changes end, or when
- // a surprise request occurs for row position during batch changes.
- // } ----- end hinting methods -----
-
- // { ----- begin searching methods -----
- NS_IMETHOD FindRowMatches( // search variable number of sorted cols
- nsIMdbEnv* ev, // context
- const mdbYarn* inPrefix, // content to find as prefix in row's column cell
- nsIMdbTableRowCursor** acqCursor) = 0; // set of matching rows
-
- NS_IMETHOD GetSearchColumns( // query columns used by FindRowMatches()
- nsIMdbEnv* ev, // context
- mdb_count* outCount, // context
- mdbColumnSet* outColSet) = 0; // caller supplied space to put columns
- // GetSearchColumns() returns the columns actually searched when the
- // FindRowMatches() method is called. No more than mColumnSet_Count
- // slots of mColumnSet_Columns will be written, since mColumnSet_Count
- // indicates how many slots are present in the column array. The
- // actual number of search column used by the table is returned in
- // the outCount parameter; if this number exceeds mColumnSet_Count,
- // then a caller needs a bigger array to read the entire column set.
- // The minimum of mColumnSet_Count and outCount is the number slots
- // in mColumnSet_Columns that were actually written by this method.
- //
- // Callers are expected to change this set of columns by calls to
- // nsIMdbTable::SearchColumnsHint() or SetSearchSorting(), or both.
- // } ----- end searching methods -----
-
- // { ----- begin sorting methods -----
- // sorting: note all rows are assumed sorted by row ID as a secondary
- // sort following the primary column sort, when table rows are sorted.
-
- NS_IMETHOD
- CanSortColumn( // query which column is currently used for sorting
- nsIMdbEnv* ev, // context
- mdb_column inColumn, // column to query sorting potential
- mdb_bool* outCanSort) = 0; // whether the column can be sorted
-
- NS_IMETHOD GetSorting( // view same table in particular sorting
- nsIMdbEnv* ev, // context
- mdb_column inColumn, // requested new column for sorting table
- nsIMdbSorting** acqSorting) = 0; // acquire sorting for column
-
- NS_IMETHOD SetSearchSorting( // use this sorting in FindRowMatches()
- nsIMdbEnv* ev, // context
- mdb_column inColumn, // often same as nsIMdbSorting::GetSortColumn()
- nsIMdbSorting* ioSorting) = 0; // requested sorting for some column
- // SetSearchSorting() attempts to inform the table that ioSorting
- // should be used during calls to FindRowMatches() for searching
- // the column which is actually sorted by ioSorting. This method
- // is most useful in conjunction with nsIMdbSorting::SetCompare(),
- // because otherwise a caller would not be able to override the
- // comparison ordering method used during searchs. Note that some
- // database implementations might be unable to use an arbitrarily
- // specified sort order, either due to schema or runtime interface
- // constraints, in which case ioSorting might not actually be used.
- // Presumably ioSorting is an instance that was returned from some
- // earlier call to nsIMdbTable::GetSorting(). A caller can also
- // use nsIMdbTable::SearchColumnsHint() to specify desired change
- // in which columns are sorted and searched by FindRowMatches().
- //
- // A caller can pass a nil pointer for ioSorting to request that
- // column inColumn no longer be used at all by FindRowMatches().
- // But when ioSorting is non-nil, then inColumn should match the
- // column actually sorted by ioSorting; when these do not agree,
- // implementations are instructed to give precedence to the column
- // specified by ioSorting (so this means callers might just pass
- // zero for inColumn when ioSorting is also provided, since then
- // inColumn is both redundant and ignored).
- // } ----- end sorting methods -----
-
- // { ----- begin moving methods -----
- // moving a row does nothing unless a table is currently unsorted
-
- NS_IMETHOD MoveOid( // change position of row in unsorted table
- nsIMdbEnv* ev, // context
- const mdbOid* inOid, // row oid to find in table
- mdb_pos inHintFromPos, // suggested hint regarding start position
- mdb_pos inToPos, // desired new position for row inRowId
- mdb_pos* outActualPos) = 0; // actual new position of row in table
-
- NS_IMETHOD MoveRow( // change position of row in unsorted table
- nsIMdbEnv* ev, // context
- nsIMdbRow* ioRow, // row oid to find in table
- mdb_pos inHintFromPos, // suggested hint regarding start position
- mdb_pos inToPos, // desired new position for row inRowId
- mdb_pos* outActualPos) = 0; // actual new position of row in table
- // } ----- end moving methods -----
-
- // { ----- begin index methods -----
- NS_IMETHOD AddIndex( // create a sorting index for column if possible
- nsIMdbEnv* ev, // context
- mdb_column inColumn, // the column to sort by index
- nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental index building
- // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
- // then the index addition will be finished.
-
- NS_IMETHOD CutIndex( // stop supporting a specific column index
- nsIMdbEnv* ev, // context
- mdb_column inColumn, // the column with index to be removed
- nsIMdbThumb** acqThumb) = 0; // acquire thumb for incremental index destroy
- // Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
- // then the index removal will be finished.
-
- NS_IMETHOD HasIndex( // query for current presence of a column index
- nsIMdbEnv* ev, // context
- mdb_column inColumn, // the column to investigate
- mdb_bool* outHasIndex) = 0; // whether column has index for this column
-
-
- NS_IMETHOD EnableIndexOnSort( // create an index for col on first sort
- nsIMdbEnv* ev, // context
- mdb_column inColumn) = 0; // the column to index if ever sorted
-
- NS_IMETHOD QueryIndexOnSort( // check whether index on sort is enabled
- nsIMdbEnv* ev, // context
- mdb_column inColumn, // the column to investigate
- mdb_bool* outIndexOnSort) = 0; // whether column has index-on-sort enabled
-
- NS_IMETHOD DisableIndexOnSort( // prevent future index creation on sort
- nsIMdbEnv* ev, // context
- mdb_column inColumn) = 0; // the column to index if ever sorted
- // } ----- end index methods -----
-
- // } ===== end nsIMdbTable methods =====
- };
-
- /*| nsIMdbSorting: a view of a table in some particular sort order. This
- **| row order closely resembles a readonly array of rows with the same row
- **| membership as the underlying table, but in a different order than the
- **| table's explicit row order. But the sorting's row membership changes
- **| whenever the table's membership changes (without any notification, so
- **| keep this in mind when modifying the table).
- **|
- **|| table: every sorting is associated with a particular table. You
- **| cannot change which table is used by a sorting (just ask some new
- **| table for a suitable sorting instance instead).
- **|
- **|| compare: the ordering method used by a sorting, wrapped up in a
- **| abstract plug-in interface. When this was never installed by an
- **| explicit call to SetNewCompare(), a compare object is still returned,
- **| and it might match the compare instance returned by the factory method
- **| nsIMdbFactory::MakeCompare(), which represents a default sort order
- **| (which we fervently hope is consistently ASCII byte ordering).
- **|
- **|| cursor: in case callers are more comfortable with a cursor style
- **| of accessing row members, each sorting will happily return a cursor
- **| instance with behavior very similar to a cursor returned from a call
- **| to nsIMdbTable::GetTableRowCursor(), but with different row order.
- **| A cursor should show exactly the same information as the pos methods.
- **|
- **|| pos: the PosToOid() and PosToRow() methods are just like the table
- **| methods of the same name, except they show rows in the sort order of
- **| the sorting, rather than that of the table. These methods are like
- **| readonly array position accessor's, or like a C++ operator[].
- |*/
- class nsIMdbSorting : public nsIMdbObject { // sorting of some table
- public:
- // { ===== begin nsIMdbSorting methods =====
-
- // { ----- begin attribute methods -----
- // sorting: note all rows are assumed sorted by row ID as a secondary
- // sort following the primary column sort, when table rows are sorted.
-
- NS_IMETHOD GetTable(nsIMdbEnv* ev, nsIMdbTable** acqTable) = 0;
- NS_IMETHOD GetSortColumn( // query which col is currently sorted
- nsIMdbEnv* ev, // context
- mdb_column* outColumn) = 0; // col the table uses for sorting (or zero)
-
- NS_IMETHOD SetNewCompare(nsIMdbEnv* ev,
- nsIMdbCompare* ioNewCompare) = 0;
- // Setting the sorting's compare object will typically cause the rows
- // to be resorted, presumably in a lazy fashion when the sorting is
- // next required to be in a valid row ordering state, such as when a
- // call to PosToOid() happens. ioNewCompare can be nil, in which case
- // implementations should revert to the default sort order, which must
- // be equivalent to whatever is used by nsIMdbFactory::MakeCompare().
-
- NS_IMETHOD GetOldCompare(nsIMdbEnv* ev,
- nsIMdbCompare** acqOldCompare) = 0;
- // Get this sorting instance's compare object, which handles the
- // ordering of rows in the sorting, by comparing yarns from the cells
- // in the column being sorted. Since nsIMdbCompare has no interface
- // to query the state of the compare object, it is not clear what you
- // would do with this object when returned, except maybe compare it
- // as a pointer address to some other instance, to check identities.
-
- // } ----- end attribute methods -----
-
- // { ----- begin cursor methods -----
- NS_IMETHOD GetSortingRowCursor( // make a cursor, starting at inRowPos
- nsIMdbEnv* ev, // context
- mdb_pos inRowPos, // zero-based ordinal position of row in table
- nsIMdbTableRowCursor** acqCursor) = 0; // acquire new cursor instance
- // A cursor interface turning same info as PosToOid() or PosToRow().
- // } ----- end row position methods -----
-
- // { ----- begin row position methods -----
- NS_IMETHOD PosToOid( // get row member for a table position
- nsIMdbEnv* ev, // context
- mdb_pos inRowPos, // zero-based ordinal position of row in table
- mdbOid* outOid) = 0; // row oid at the specified position
-
- NS_IMETHOD PosToRow( // test for the table position of a row member
- nsIMdbEnv* ev, // context
- mdb_pos inRowPos, // zero-based ordinal position of row in table
- nsIMdbRow** acqRow) = 0; // acquire row at table position inRowPos
- // } ----- end row position methods -----
-
- // } ===== end nsIMdbSorting methods =====
- };
-
- /*| nsIMdbTableRowCursor: cursor class for iterating table rows
- **|
- **|| table: the cursor is associated with a specific table, which can be
- **| set to a different table (which resets the position to -1 so the
- **| next row acquired is the first in the table.
- **|
- **|| NextRowId: the rows in the table can be iterated by identity alone,
- **| without actually reading the cells of any row with this method.
- **|
- **|| NextRowCells: read the next row in the table, but only read cells
- **| from the table which are already present in the row (so no new cells
- **| are added to the row, even if they are present in the table). All the
- **| cells will have content specified, even it is the empty string. No
- **| columns will be removed, even if missing from the row (because missing
- **| and empty are semantically equivalent).
- **|
- **|| NextRowAllCells: read the next row in the table, and access all the
- **| cells for this row in the table, adding any missing columns to the row
- **| as needed until all cells are represented. All the
- **| cells will have content specified, even it is the empty string. No
- **| columns will be removed, even if missing from the row (because missing
- **| and empty are semantically equivalent).
- **|
- |*/
-
- #define NS_IMDBTABLEROWCURSOR_IID_STR = "4f325dad-0385-4b62-a992-c914ab93587e"
-
- #define NS_IMDBTABLEROWCURSOR_IID \
- {0x4f325dad, 0x0385, 0x4b62, \
- {0xa9, 0x92, 0xc9, 0x14, 0xab, 0x93, 0x58, 0x7e}}
-
-
-
- class nsIMdbTableRowCursor : public nsISupports { // table row iterator
- public:
- NS_DEFINE_STATIC_IID_ACCESSOR(NS_IMDBTABLEROWCURSOR_IID)
-
- // { ===== begin nsIMdbTableRowCursor methods =====
-
- // { ----- begin attribute methods -----
- // NS_IMETHOD SetTable(nsIMdbEnv* ev, nsIMdbTable* ioTable) = 0; // sets pos to -1
- // Method SetTable() cut and made obsolete in keeping with new sorting methods.
-
- NS_IMETHOD GetTable(nsIMdbEnv* ev, nsIMdbTable** acqTable) = 0;
- // } ----- end attribute methods -----
-
- // { ----- begin duplicate row removal methods -----
- NS_IMETHOD CanHaveDupRowMembers(nsIMdbEnv* ev, // cursor might hold dups?
- mdb_bool* outCanHaveDups) = 0;
-
- NS_IMETHOD MakeUniqueCursor( // clone cursor, removing duplicate rows
- nsIMdbEnv* ev, // context
- nsIMdbTableRowCursor** acqCursor) = 0; // acquire clone with no dups
- // Note that MakeUniqueCursor() is never necessary for a cursor which was
- // created by table method nsIMdbTable::GetTableRowCursor(), because a table
- // never contains the same row as a member more than once. However, a cursor
- // created by table method nsIMdbTable::FindRowMatches() might contain the
- // same row more than once, because the same row can generate a hit by more
- // than one column with a matching string prefix. Note this method can
- // return the very same cursor instance with just an incremented refcount,
- // when the original cursor could not contain any duplicate rows (calling
- // CanHaveDupRowMembers() shows this case on a false return). Otherwise
- // this method returns a different cursor instance. Callers should not use
- // this MakeUniqueCursor() method lightly, because it tends to defeat the
- // purpose of lazy programming techniques, since it can force creation of
- // an explicit row collection in a new cursor's representation, in order to
- // inspect the row membership and remove any duplicates; this can have big
- // impact if a collection holds tens of thousands of rows or more, when
- // the original cursor with dups simply referenced rows indirectly by row
- // position ranges, without using an explicit row set representation.
- // Callers are encouraged to use nsIMdbCursor::GetCount() to determine
- // whether the row collection is very large (tens of thousands), and to
- // delay calling MakeUniqueCursor() when possible, until a user interface
- // element actually demands the creation of an explicit set representation.
- // } ----- end duplicate row removal methods -----
-
- // { ----- begin oid iteration methods -----
- NS_IMETHOD NextRowOid( // get row id of next row in the table
- nsIMdbEnv* ev, // context
- mdbOid* outOid, // out row oid
- mdb_pos* outRowPos) = 0; // zero-based position of the row in table
- // } ----- end oid iteration methods -----
-
- // { ----- begin row iteration methods -----
- NS_IMETHOD NextRow( // get row cells from table for cells already in row
- nsIMdbEnv* ev, // context
- nsIMdbRow** acqRow, // acquire next row in table
- mdb_pos* outRowPos) = 0; // zero-based position of the row in table
-
- NS_IMETHOD PrevRowOid( // get row id of previous row in the table
- nsIMdbEnv* ev, // context
- mdbOid* outOid, // out row oid
- mdb_pos* outRowPos) = 0; // zero-based position of the row in table
- // } ----- end oid iteration methods -----
-
- // { ----- begin row iteration methods -----
- NS_IMETHOD PrevRow( // get row cells from table for cells already in row
- nsIMdbEnv* ev, // context
- nsIMdbRow** acqRow, // acquire previous row in table
- mdb_pos* outRowPos) = 0; // zero-based position of the row in table
-
- // } ----- end row iteration methods -----
-
- // { ----- begin copy iteration methods -----
- // NS_IMETHOD NextRowCopy( // put row cells into sink only when already in sink
- // nsIMdbEnv* ev, // context
- // nsIMdbRow* ioSinkRow, // sink for row cells read from next row
- // mdbOid* outOid, // out row oid
- // mdb_pos* outRowPos) = 0; // zero-based position of the row in table
- //
- // NS_IMETHOD NextRowCopyAll( // put all row cells into sink, adding to sink
- // nsIMdbEnv* ev, // context
- // nsIMdbRow* ioSinkRow, // sink for row cells read from next row
- // mdbOid* outOid, // out row oid
- // mdb_pos* outRowPos) = 0; // zero-based position of the row in table
- // } ----- end copy iteration methods -----
-
- // } ===== end nsIMdbTableRowCursor methods =====
- };
-
- /*| nsIMdbRow: a collection of cells
- **|
- |*/
-
- #define NS_IMDBROW_IID_STR "271e8d6e-183a-40e3-9f18-36913b4c7853"
-
-
- #define NS_IMDBROW_IID \
- {0x271e8d6e, 0x183a, 0x40e3, \
- {0x9f, 0x18, 0x36, 0x91, 0x3b, 0x4c, 0x78, 0x53}}
-
-
- class nsIMdbRow : public nsIMdbCollection { // cell tuple
- public:
-
- NS_DEFINE_STATIC_IID_ACCESSOR(NS_IMDBROW_IID)
- // { ===== begin nsIMdbRow methods =====
-
- // { ----- begin cursor methods -----
- NS_IMETHOD GetRowCellCursor( // make a cursor starting iteration at inCellPos
- nsIMdbEnv* ev, // context
- mdb_pos inCellPos, // zero-based ordinal position of cell in row
- nsIMdbRowCellCursor** acqCursor) = 0; // acquire new cursor instance
- // } ----- end cursor methods -----
-
- // { ----- begin column methods -----
- NS_IMETHOD AddColumn( // make sure a particular column is inside row
- nsIMdbEnv* ev, // context
- mdb_column inColumn, // column to add
- const mdbYarn* inYarn) = 0; // cell value to install
-
- NS_IMETHOD CutColumn( // make sure a column is absent from the row
- nsIMdbEnv* ev, // context
- mdb_column inColumn) = 0; // column to ensure absent from row
-
- NS_IMETHOD CutAllColumns( // remove all columns from the row
- nsIMdbEnv* ev) = 0; // context
- // } ----- end column methods -----
-
- // { ----- begin cell methods -----
- NS_IMETHOD NewCell( // get cell for specified column, or add new one
- nsIMdbEnv* ev, // context
- mdb_column inColumn, // column to add
- nsIMdbCell** acqCell) = 0; // cell column and value
-
- NS_IMETHOD AddCell( // copy a cell from another row to this row
- nsIMdbEnv* ev, // context
- const nsIMdbCell* inCell) = 0; // cell column and value
-
- NS_IMETHOD GetCell( // find a cell in this row
- nsIMdbEnv* ev, // context
- mdb_column inColumn, // column to find
- nsIMdbCell** acqCell) = 0; // cell for specified column, or null
-
- NS_IMETHOD EmptyAllCells( // make all cells in row empty of content
- nsIMdbEnv* ev) = 0; // context
- // } ----- end cell methods -----
-
- // { ----- begin row methods -----
- NS_IMETHOD AddRow( // add all cells in another row to this one
- nsIMdbEnv* ev, // context
- nsIMdbRow* ioSourceRow) = 0; // row to union with
-
- NS_IMETHOD SetRow( // make exact duplicate of another row
- nsIMdbEnv* ev, // context
- nsIMdbRow* ioSourceRow) = 0; // row to duplicate
- // } ----- end row methods -----
-
- // { ----- begin blob methods -----
- NS_IMETHOD SetCellYarn(nsIMdbEnv* ev, // synonym for AddColumn()
- mdb_column inColumn, // column to write
- const mdbYarn* inYarn) = 0; // reads from yarn slots
- // make this text object contain content from the yarn's buffer
-
- NS_IMETHOD GetCellYarn(nsIMdbEnv* ev,
- mdb_column inColumn, // column to read
- mdbYarn* outYarn) = 0; // writes some yarn slots
- // copy content into the yarn buffer, and update mYarn_Fill and mYarn_Form
-
- NS_IMETHOD AliasCellYarn(nsIMdbEnv* ev,
- mdb_column inColumn, // column to alias
- mdbYarn* outYarn) = 0; // writes ALL yarn slots
-
- NS_IMETHOD NextCellYarn(nsIMdbEnv* ev, // iterative version of GetCellYarn()
- mdb_column* ioColumn, // next column to read
- mdbYarn* outYarn) = 0; // writes some yarn slots
- // copy content into the yarn buffer, and update mYarn_Fill and mYarn_Form
- //
- // The ioColumn argument is an inout parameter which initially contains the
- // last column accessed and returns the next column corresponding to the
- // content read into the yarn. Callers should start with a zero column
- // value to say 'no previous column', which causes the first column to be
- // read. Then the value returned in ioColumn is perfect for the next call
- // to NextCellYarn(), since it will then be the previous column accessed.
- // Callers need only examine the column token returned to see which cell
- // in the row is being read into the yarn. When no more columns remain,
- // and the iteration has ended, ioColumn will return a zero token again.
- // So iterating over cells starts and ends with a zero column token.
-
- NS_IMETHOD SeekCellYarn( // resembles nsIMdbRowCellCursor::SeekCell()
- nsIMdbEnv* ev, // context
- mdb_pos inPos, // position of cell in row sequence
- mdb_column* outColumn, // column for this particular cell
- mdbYarn* outYarn) = 0; // writes some yarn slots
- // copy content into the yarn buffer, and update mYarn_Fill and mYarn_Form
- // Callers can pass nil for outYarn to indicate no interest in content, so
- // only the outColumn value is returned. NOTE to subclasses: you must be
- // able to ignore outYarn when the pointer is nil; please do not crash.
-
- // } ----- end blob methods -----
-
- // } ===== end nsIMdbRow methods =====
- };
-
- /*| nsIMdbRowCellCursor: cursor class for iterating row cells
- **|
- **|| row: the cursor is associated with a specific row, which can be
- **| set to a different row (which resets the position to -1 so the
- **| next cell acquired is the first in the row.
- **|
- **|| NextCell: get the next cell in the row and return its position and
- **| a new instance of a nsIMdbCell to represent this next cell.
- |*/
-
- #define NS_IMDBROWCELLCURSOR_IID_STR "b33371a7-5d63-4d10-85a8-e44dffe75c28"
-
-
- #define NS_IMDBROWCELLCURSOR_IID \
- {0x271e8d6e, 0x5d63, 0x4d10 , \
- {0x85, 0xa8, 0xe4, 0x4d, 0xff, 0xe7, 0x5c, 0x28}}
-
-
- class nsIMdbRowCellCursor : public nsISupports{ // cell collection iterator
- public:
-
- NS_DEFINE_STATIC_IID_ACCESSOR(NS_IMDBROWCELLCURSOR_IID)
- // { ===== begin nsIMdbRowCellCursor methods =====
-
- // { ----- begin attribute methods -----
- NS_IMETHOD SetRow(nsIMdbEnv* ev, nsIMdbRow* ioRow) = 0; // sets pos to -1
- NS_IMETHOD GetRow(nsIMdbEnv* ev, nsIMdbRow** acqRow) = 0;
- // } ----- end attribute methods -----
-
- // { ----- begin cell creation methods -----
- NS_IMETHOD MakeCell( // get cell at current pos in the row
- nsIMdbEnv* ev, // context
- mdb_column* outColumn, // column for this particular cell
- mdb_pos* outPos, // position of cell in row sequence
- nsIMdbCell** acqCell) = 0; // the cell at inPos
- // } ----- end cell creation methods -----
-
- // { ----- begin cell seeking methods -----
- NS_IMETHOD SeekCell( // same as SetRow() followed by MakeCell()
- nsIMdbEnv* ev, // context
- mdb_pos inPos, // position of cell in row sequence
- mdb_column* outColumn, // column for this particular cell
- nsIMdbCell** acqCell) = 0; // the cell at inPos
- // } ----- end cell seeking methods -----
-
- // { ----- begin cell iteration methods -----
- NS_IMETHOD NextCell( // get next cell in the row
- nsIMdbEnv* ev, // context
- nsIMdbCell** acqCell, // changes to the next cell in the iteration
- mdb_column* outColumn, // column for this particular cell
- mdb_pos* outPos) = 0; // position of cell in row sequence
-
- NS_IMETHOD PickNextCell( // get next cell in row within filter set
- nsIMdbEnv* ev, // context
- nsIMdbCell* ioCell, // changes to the next cell in the iteration
- const mdbColumnSet* inFilterSet, // col set of actual caller interest
- mdb_column* outColumn, // column for this particular cell
- mdb_pos* outPos) = 0; // position of cell in row sequence
-
- // Note that inFilterSet should not have too many (many more than 10?)
- // cols, since this might imply a potential excessive consumption of time
- // over many cursor calls when looking for column and filter intersection.
- // } ----- end cell iteration methods -----
-
- // } ===== end nsIMdbRowCellCursor methods =====
- };
-
- /*| nsIMdbBlob: a base class for objects composed mainly of byte sequence state.
- **| (This provides a base class for nsIMdbCell, so that cells themselves can
- **| be used to set state in another cell, without extracting a buffer.)
- |*/
- class nsIMdbBlob : public nsISupports { // a string with associated charset
- public:
-
- // { ===== begin nsIMdbBlob methods =====
-
- // { ----- begin attribute methods -----
- NS_IMETHOD SetBlob(nsIMdbEnv* ev,
- nsIMdbBlob* ioBlob) = 0; // reads inBlob slots
- // when inBlob is in the same suite, this might be fastest cell-to-cell
-
- NS_IMETHOD ClearBlob( // make empty (so content has zero length)
- nsIMdbEnv* ev) = 0;
- // clearing a yarn is like SetYarn() with empty yarn instance content
-
- NS_IMETHOD GetBlobFill(nsIMdbEnv* ev,
- mdb_fill* outFill) = 0; // size of blob
- // Same value that would be put into mYarn_Fill, if one called GetYarn()
- // with a yarn instance that had mYarn_Buf==nil and mYarn_Size==0.
-
- NS_IMETHOD SetYarn(nsIMdbEnv* ev,
- const mdbYarn* inYarn) = 0; // reads from yarn slots
- // make this text object contain content from the yarn's buffer
-
- NS_IMETHOD GetYarn(nsIMdbEnv* ev,
- mdbYarn* outYarn) = 0; // writes some yarn slots
- // copy content into the yarn buffer, and update mYarn_Fill and mYarn_Form
-
- NS_IMETHOD AliasYarn(nsIMdbEnv* ev,
- mdbYarn* outYarn) = 0; // writes ALL yarn slots
- // AliasYarn() reveals sensitive internal text buffer state to the caller
- // by setting mYarn_Buf to point into the guts of this text implementation.
- //
- // The caller must take great care to avoid writing on this space, and to
- // avoid calling any method that would cause the state of this text object
- // to change (say by directly or indirectly setting the text to hold more
- // content that might grow the size of the buffer and free the old buffer).
- // In particular, callers should scrupulously avoid making calls into the
- // mdb interface to write any content while using the buffer pointer found
- // in the returned yarn instance. Best safe usage involves copying content
- // into some other kind of external content representation beyond mdb.
- //
- // (The original design of this method a week earlier included the concept
- // of very fast and efficient cooperative locking via a pointer to some lock
- // member slot. But let's ignore that complexity in the current design.)
- //
- // AliasYarn() is specifically intended as the first step in transferring
- // content from nsIMdbBlob to a nsString representation, without forcing extra
- // allocations and/or memory copies. (A standard nsIMdbBlob_AsString() utility
- // will use AliasYarn() as the first step in setting a nsString instance.)
- //
- // This is an alternative to the GetYarn() method, which has copy semantics
- // only; AliasYarn() relaxes a robust safety principle only for performance
- // reasons, to accomodate the need for callers to transform text content to
- // some other canonical representation that would necessitate an additional
- // copy and transformation when such is incompatible with the mdbYarn format.
- //
- // The implementation of AliasYarn() should have extremely little overhead
- // besides the virtual dispatch to the method implementation, and the code
- // necessary to populate all the mdbYarn member slots with internal buffer
- // address and metainformation that describes the buffer content. Note that
- // mYarn_Grow must always be set to nil to indicate no resizing is allowed.
-
- // } ----- end attribute methods -----
-
- // } ===== end nsIMdbBlob methods =====
- };
-
- /*| nsIMdbCell: the text in a single column of a row. The base nsIMdbBlob
- **| class provides all the interface related to accessing cell text.
- **|
- **|| column: each cell in a row appears in a specific column, where this
- **| column is identified by the an integer mdb_scope value (generated by
- **| the StringToScopeToken() method in the containing nsIMdbPort instance).
- **| Because a row cannot have more than one cell with the same column,
- **| something must give if one calls SetColumn() with an existing column
- **| in the same row. When this happens, the other cell is replaced with
- **| this cell (and the old cell is closed if it has outstanding refs).
- **|
- **|| row: every cell instance is a part of some row, and every cell knows
- **| which row is the parent row. (Note this should be represented by a
- **| weak backpointer, so that outstanding cell references cannot keep a
- **| row open that should be closed. Otherwise we'd have ref graph cycles.)
- **|
- **|| text: a cell can either be text, or it can have a child row or table,
- **| but not both at once. If text is read from a cell with a child, the text
- **| content should be empty (for AliasYarn()) or a description of the type
- **| of child (perhaps "mdb:cell:child:row" or "mdb:cell:child:table").
- **|
- **|| child: a cell might reference another row or a table, rather than text.
- **| The interface for putting and getting children rows and tables was first
- **| defined in the nsIMdbTable interface, but then this was moved to this cell
- **| interface as more natural.
- |*/
-
-
-
- #define NS_IMDBCELL_IID \
- {0xa3b62f71, 0xa181, 0x4a91, \
- {0xb6, 0x6b, 0x27, 0x10, 0x9b, 0x88, 0x98, 0x35}}
-
- #define NS_IMDBCELL_IID_STR = "a3b62f71-a181-4a91-b66b-27109b889835"
-
- class nsIMdbCell : public nsIMdbBlob { // text attribute in row with column scope
- public:
-
- NS_DEFINE_STATIC_IID_ACCESSOR(NS_IMDBTABLEROWCURSOR_IID)
- // { ===== begin nsIMdbCell methods =====
-
- // { ----- begin attribute methods -----
- NS_IMETHOD SetColumn(nsIMdbEnv* ev, mdb_column inColumn) = 0;
- NS_IMETHOD GetColumn(nsIMdbEnv* ev, mdb_column* outColumn) = 0;
-
- NS_IMETHOD GetCellInfo( // all cell metainfo except actual content
- nsIMdbEnv* ev,
- mdb_column* outColumn, // the column in the containing row
- mdb_fill* outBlobFill, // the size of text content in bytes
- mdbOid* outChildOid, // oid of possible row or table child
- mdb_bool* outIsRowChild) = 0; // nonzero if child, and a row child
-
- // Checking all cell metainfo is a good way to avoid forcing a large cell
- // in to memory when you don't actually want to use the content.
-
- NS_IMETHOD GetRow(nsIMdbEnv* ev, // parent row for this cell
- nsIMdbRow** acqRow) = 0;
- NS_IMETHOD GetPort(nsIMdbEnv* ev, // port containing cell
- nsIMdbPort** acqPort) = 0;
- // } ----- end attribute methods -----
-
- // { ----- begin children methods -----
- NS_IMETHOD HasAnyChild( // does cell have a child instead of text?
- nsIMdbEnv* ev,
- mdbOid* outOid, // out id of row or table (or unbound if no child)
- mdb_bool* outIsRow) = 0; // nonzero if child is a row (rather than a table)
-
- NS_IMETHOD GetAnyChild( // access table of specific attribute
- nsIMdbEnv* ev, // context
- nsIMdbRow** acqRow, // child row (or null)
- nsIMdbTable** acqTable) = 0; // child table (or null)
-
-
- NS_IMETHOD SetChildRow( // access table of specific attribute
- nsIMdbEnv* ev, // context
- nsIMdbRow* ioRow) = 0; // inRow must be bound inside this same db port
-
- NS_IMETHOD GetChildRow( // access row of specific attribute
- nsIMdbEnv* ev, // context
- nsIMdbRow** acqRow) = 0; // acquire child row (or nil if no child)
-
-
- NS_IMETHOD SetChildTable( // access table of specific attribute
- nsIMdbEnv* ev, // context
- nsIMdbTable* inTable) = 0; // table must be bound inside this same db port
-
- NS_IMETHOD GetChildTable( // access table of specific attribute
- nsIMdbEnv* ev, // context
- nsIMdbTable** acqTable) = 0; // acquire child table (or nil if no child)
- // } ----- end children methods -----
-
- // } ===== end nsIMdbCell methods =====
- };
-
- // } %%%%% end C++ abstract class interfaces %%%%%
-
- //3456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789
-
- #endif /* _MDB_ */
-
-