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1998-04-27
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TABLE OF CONTENTS
xpkmaster.library/XpkAllocObject
xpkmaster.library/XpkClose
xpkmaster.library/XpkExamine
xpkmaster.library/XpkFault
xpkmaster.library/XpkFreeObject
xpkmaster.library/XpkOpen
xpkmaster.library/XpkPack
xpkmaster.library/XpkPassRequest
xpkmaster.library/XpkPrintFault
xpkmaster.library/XpkQuery
xpkmaster.library/XpkRead
xpkmaster.library/XpkUnpack
xpkmaster.library/XpkWrite
xpkmaster.library/--tags--
xpkmaster.library/--progress--
xpkmaster.library/--data hooks--
xpkmaster.library/XpkAllocObject xpkmaster.library/XpkAllocObject
NAME
XpkAllocObject - Allocate memory for xpk related structures (V4)
SYNOPSIS
ptr = XpkAllocObject(type, tags)
D0 D0 A0
APTR XpkAllocObject(ULONG , struct TagItem *)
ptr = XpkAllocObjectTags(type, firsttag, ...)
APTR XpkAllocObjectTags(ULONG, Tag, ...)
FUNCTION
This function allocates the memory of a needed xpk related
structure and initializes it. It should help to bring better
upwards compatibility in next versions. Use it always in newer code.
INPUT
type - in xpk/xpk.h defined XPKOBJ_... types.
for example XPKOBJ_FIB alloctes XpkFib structure
tags - Pointer to an array of struct TagItem. No tags defined
at the moment.
RESULT
ptr - Pointer to allocated memory of needed size or 0 when an
error occured.
SEE ALSO
xpk/xpk.h, XpkFreeObject()
xpkmaster.library/XpkClose xpkmaster.library/XpkClose
NAME
XpkClose - Close an XPK-File
SYNOPSIS
err = XpkClose(xfh)
D0 A0
LONG XpkClose(struct XpkFib *)
FUNCTION
Frees all resources associated with packing or unpacking an
XPK-File. Note that this may well fail, especially on packing,
since additional writes have to be made here.
INPUT
xfh - The Struct XpkFib obtained from XpkOpen()
RESULT
err - Global Xpk error code
SEE ALSO
XpkOpen(), XpkRead(), XpkWrite()
xpkmaster.library/XpkExamine xpkmaster.library/XpkExamine
NAME
XpkExamine - Get information about a compressed file
SYNOPSIS
err = XpkExamine(fib, tags)
D0 A0 A1
LONG XpkExamine(struct XpkFib *, struct TagItem *)
err = XpkExamineTags(fib, firsttag, ...)
LONG XpkExamineTags(struct XpkFib *, Tag, ...)
FUNCTION
Returns information about compressed data. The output is written
to the XpkFib structure whose address is passed with the mandatory
XPK_FileExamine tag. You also have to specify an XPK_In* tag. Note
that the file position of the in hook will not be altered.
XPK_GetError is supported.
A tag field has to end with TAG_DONE.
INPUT
tags - Pointer to an array of struct TagItem. You may use
either a XPK_InBuf, a XPK_InName, XPK_InFH or XPK_InHook
tag.
RESULT
err - Global Xpk error code
SEE ALSO
xpk/xpk.h
xpkmaster.library/XpkFault xpkmaster.library/XpkFault
NAME
XpkFault - Returns the text associated with a Xpk error code (V4)
SYNOPSIS
len = XpkFault(code, header, buffer, bufsize)
D0 D0 A0 A1 D1
LONG XpkFault(LONG, STRPTR, STRPTR, LONG)
FUNCTION
This routine obtains the error message text for the given error code.
The header is prepended to the text of the error message, followed
by a colon. Puts a null-terminated string for the error message into
the buffer. At most len bytes are written to buffer.
INPUTS
code - Error code (negative value or 0)
header - header to output before error text
buffer - Buffer to receive error message.
bufsize - Length of the buffer.
RESULT
len - number of characters put into buffer (may be 0)
SEE ALSO
XpkPrintFault()
xpkmaster.library/XpkFreeObject xpkmaster.library/XpkFreeObject
NAME
XpkFreeObject - Frees memory allocated with XpkAllocObject() (V4)
SYNOPSIS
XpkFreeObject(type, object)
D0 A0
void XpkFreeObject(ULONG , APTR)
FUNCTION
Frees object allocated by XpkAllocObject(). Do not call for objects
allocated in any other way.
INPUTS
type - type passed to XpkAllocObject()
object - pointer returned by XpkAllocObject()
SEE ALSO
xpk/xpk.h, XpkAllocObject()
xpkmaster.library/XpkOpen xpkmaster.library/XpkOpen
NAME
XpkOpen - Open a compressed file for partial reading
SYNOPSIS
err = XpkOpen(xfh, tags)
D0 A0 A1
LONG XpkOpen(struct XpkFib **, struct TagItem *)
FUNCTION
Using XpkOpen you can read or write an XPK file without ever having
all of the file present in RAM. On reading, you cannot pick the
size of the chunks. They are given by the file to be decompressed
and may be up to the whole size of the file.
XPK_GetError is supported.
INPUT
xfh - Address of a pointer to struct XpkFib
tags - Specifying XPK_PackMethod will chose packing mode for
this filehandle. Only In-tags are permitted in case
of unpacking, and only Out-tags are in case of packing.
Anything else will yield undefined results. Progress
reports not supported. When packing, you must supply
XPK_InLen as well.
RESULT
xfh - The filehandle. Consists of an XpkFib and some private
information. The NLen field in the XpkFib indicates the
length of the next chunk.
err - Global Xpk error code. If nonzero, no XpkFib was allocated.
SEE ALSO
XpkRead(), XpkWrite(), XpkClose(), xpkmaster.library/--tags--
xpkmaster.library/XpkPack xpkmaster.library/XpkPack
NAME
XpkPack - Compress a data stream
SYNOPSIS
err = XpkPack(tags)
D0 A0
LONG XpkPack(struct TagItem *)
err = XpkPackTags(firsttag, ...)
LONG XpkPackTags(Tag, ...)
FUNCTION
Compresses a file or a memory area to a different file or memory
area. You need to specify at least one XPK_In... tag, at least
one XPK_Out... tag, plus XPK_PackMethod.
XPK_GetError is supported.
A tag field has to end with TAG_DONE.
INPUT
tags - Pointer to an array of struct TagItem.
RESULT
err - Global Xpk error code.
SEE ALSO
xpkmaster.library/--tags--, xpk/xpk.h
xpkmaster.library/XpkPassRequest xpkmaster.library/XpkPassRequest
NAME
XpkPassRequest - opens a password Requester (V4)
SYNOPSIS
err = XpkPassRequest(tags)
D0 A0
LONG XpkPassRequest(struct TagItem *)
err = XpkPassRequestTags(firsttag, ...)
LONG XpkPassRequestTags(Tag, ...)
FUNCTION
Opens a requester to ask the user for a password. The requester
can ask for a password or a 16/32 bit key. It has a tunable
timeout to allow batch work.
This function needs at least 2 free signal bits for message ports.
INPUT
tags - Pointer to an array of struct TagItem.
Either XPK_Preferences or one of the following:
TAGS
XPK_PassChars (ULONG)
Tell the requester which characters are allowed in the password.
Use XPKPASSFLG_... and XPKPASSFF_... defines.
XPK_PasswordBuf (STRPTR)
Pointer to memory area, where the password should be stored.
Requires XPK_PassBuffSize tag.
XPK_PassBufSize (ULONG)
Size of the buffer passed with XPK_PasswordBuf.
XPK_Key16BitPtr (UWORD *)
Ask for an 16 bit key instead of a password. Data is a pointer
to a 16 bit (UWORD) variable. XPK_PassChars is ignored here, as
input is always hexadecimal.
XPK_Key32BitPtr (ULONG *)
Ask for an 32 bit key. Data points to a 32 bit (ULONG) variable.
XPK_PassChars is ignored here, as input is always hexadecimal.
XPK_PubScreen (struct Screen *)
Pointer of type struct Screen of the public screen, the
requester should open on. If not given, the requester opens on
default public screen. The screen must by locked by use of
LockPubScreen or garanted not to be closed during request!
XPK_PassTitle (STRPTR)
Is the text, which is shown in the title line of the window. If
not given, the internal defaults are used.
XPK_TimeOut (ULONG)
Time after which the requester should close automatically, when
no user action happend. 0 means no timeout.
XPK_PassVerify (BOOL) (V4 REV25)
When this tag is specified, the user needs to enter the password
or passkey twice for verification. This option should be used
when password is needed for packing.
XPK_PassWinLeft (UWORD) (V4 REV25)
This specifies the distance from left screen border to left
border of password requester. When not given, the window is
centered on screen.
XPK_PassWinTop (UWORD) (V4 REV25)
This specifies the distance from top screen border to top
border of password requester. When not given, the window is
centered on screen.
XPK_PassWinWidth (UWORD) (V4 REV25)
This specifies the width of the password requester. It must be
large enough (50 + borders) or the internal defaults are used.
XPK_PassWinHeight (UWORD) (V4 REV25)
This specifies the height of the password requester. It must be
large enough (inner height a bit larger than font height) or the
internal defaults are used.
XPK_PassCenter (BOOL) (V4 REV25)
When this is given, the above XPK_PassWinLeft and XPK_PassWinTop
are are interpreted as the center of the requester and not as
its upper left edge.
RESULT
err - Global Xpk error code.
SEE ALSO
xpk/xpk.h
xpkmaster.library/XpkPrintFault xpkmaster.library/XpkPrintFault
NAME
XpkPrintFault - Prints the text associated with a Xpk error code (V4)
SYNOPSIS
success = XpkPrintFault(code, header)
D0 D0 A0
BOOL XpkPrintFault(LONG, STRPTR)
FUNCTION
This routine obtains and prints the error message text for the
given error code. This is similar to the XpkFault() function,
except that the output is written to the default output
channel with buffered output.
INPUTS
code - Error code (negative value or 0)
header - header to output before error text
RESULT
success - Success/failure code. Return of 0 means failure.
SEE ALSO
XpkFault()
xpkmaster.library/XpkQuery xpkmaster.library/XpkQuery
NAME
XpkQuery - Gain information about packers
SYNOPSIS
err = XpkQuery(tags)
D0 A0
LONG XpkQuery(struct TagItem *)
err = XpkQueryTags(firsttag, ...)
LONG XpkQueryTags(Tag, ... )
FUNCTION
Finds out a list of available packers or various parameters of a
packer. When using the tag XPK_PackersQuery, you must supply a
XpkPackerList structure and will receive a list of available
packers. The second possibility, XPK_PackerQuery, expects a
pointer to a XpkPackerInfo structure which will be filled in with
information about a packer, and XPK_ModeQuery fills in a XpkMode
structure with information about some mode (or the default mode)
of a packer. XPK_PackMethod must be present when using the latter
two queries, and XPK_PackMode can be for ModeQuery.
XPK_GetError is supported. Every call only one query is allowed!
The flag XPKIF_MODES does not mean, the library supports different
mode settings (as ALL libraries do that), but means there are
different XpkMode structures! So when XPKIF_MODES is not set, the
user still needs to be able to select all 100 modes!
Pass {XPK_Preferences, FALSE} as tags to disable the dummy packer
USER, which implements the preferences packing. Then handle the
preferences mode internally, as the statistics passed with
XPK_ModeQuery and XPK_PackerQuery are not very useful.
RESULT
err - Global Xpk error code.
SEE ALSO
xpk/xpk.h
xpkmaster.library/XpkRead xpkmaster.library/XpkRead
NAME
XpkRead - Unpack one part of an XPK-File
SYNOPSIS
read = XpkRead( xfh, buf, len )
D0 A0 A1 D0
LONG XpkRead(struct XpkFib *, UBYTE *, LONG)
FUNCTION
Reads one chunk from an XPK-file and decompresses it to the
memory area indicated.
INPUT
xfh - The XpkFib obtained from XpkOpen(). It must be a read-
handle, ie. there was no XPK_PackMethod tag among the
tags passed to XpkOpen().
buf - The memory area to write the destination to
len - The number uncompressed bytes to output. Note that you
cannot choose these freely but must take them from
the xf_NLen field in the XpkFib.
RESULT
read - The number of bytes read. 0 indicates EOF, negative
numbers are global error codes. Long error messages
written to buffer passed through XPK_GetError in
XpkOpen(). This number of bytes read will usually be
smaller than the number requested!
SEE ALSO
XpkOpen(), XpkWrite(), XpkClose(), examples/
xpkmaster.library/XpkUnpack xpkmaster.library/XpkUnpack
NAME
XpkUnpack - Decompress a data stream
SYNOPSIS
err = XpkUnpack(tags)
D0 A0
LONG XpkUnpack(struct TagItem *)
err = XpkUnpackTags(firsttag, ...)
LONG XpkUnpackTags(Tag, ...)
FUNCTION
Decompresses a file or a memory area to a different file or memory
area. You need to specify at least one XPK_In... tag, at least
one XPK_Out... tag. A tag field has to end with TAG_DONE.
XPK_GetError is supported.
INPUT
tags - Pointer to an array of struct TagItem.
RESULT
err - Global Xpk error code.
SEE ALSO
xpkmaster.library/--tags--
xpkmaster.library/XpkWrite xpkmaster.library/XpkWrite
NAME
XpkWrite - Pack one part of an XPK-File
SYNOPSIS
read = XpkWrite(xfh, buf, len)
D0 A0 A1 D0
LONG XpkWrite(struct XpkFib *, UBYTE *, LONG)
FUNCTION
Compresses the memory area indicated and writes it to an
XPK-File.
INPUT
xfh - The XpkFib obtained from XpkOpen(). Must be a write-
handle, ie. XPK_PackMethod must have been among the
tags passed to XpkOpen().
buf - The memory area to compress
len - The number bytes to compress. Note you may not choose
them freely, you must always deliver as many bytes
as the NLen field of the XpkFib indicates. You may try
to influence it by passing XPK_ChunkLen to XpkOpen().
Important: The first chunk written *must* be the
biggest!
RESULT
written - The number of bytes written. 0 indicates EOF, negative
numbers are global error codes. Error messages are
written to buffer passed through XPK_GetError in
XpkOpen().
SEE ALSO
XpkOpen(), XpkRead(), XpkClose(), examples/
xpkmaster.library/--tags-- xpkmaster.library/--tags--
THE TAGS FOR XpkPack() AND XpkUnpack()
THE INPUT TAGS. One of the four must be present.
XPK_InName (STRPTR)
Name of file to (de)compress. On packing, XPK_InLen can be
specified in order to pack only the first N bytes. On de-
compression, only one file will be decompressed, even if
there is additional data at the end.
XPK_InFH (BPTR)
File handle to (de)compress from. It is not necessary that
the handle is at the beginning of the file. Otherwise same
rules as in XPK_InName apply.
XPK_InBuf (STRPTR)
Memory block to (de)compress. If you use this one, you
have to specify InLen as well.
XPK_InHook (struct Hook *)
Hookfunc to deliver data for (de)compression. See special
chapter on I/O hook functions. Must also supply XPK_InLen,
else the hook itself is asked for input filelength.
IN ADDITION
XPK_InLen (LONG)
Specifies the number of bytes to read when compressing.
ignored on decompression of normal xpk files. It should be
supplied for decompression to allow decrunching of non xpk
files.
THE OUTPUT TAGS. One of the five must be present.
XPK_OutName (STRPTR)
Name of file write (de)compressed data to.
XPK_OutFH (BPTR)
File handle to append (de)compressed data to. This filehandle
must be writable, so MODE_OLDFILE filehandles may fail, as
these open a file in shared mode.
XPK_OutBuf (APTR)
The memory block to write (de)compressed data to. Must also
supply XPK_OutBufLen. On packing, its size must be at least
inlen+inlen/32+2*XPK_MARGIN. On unpacking, it needs only be
outlen+XPK_MARGIN. Use XpkExamine() to find out outlen. Note
that this buffer must be word aligned.
XPK_GetOutBuf (APTR *)
Allocates a block of appropriate size and stores a pointer to
it in the variable pointed to by ti_Data. Must also supply
XPK_GetOutBufLen plus XPK_GetOutLen and can XPK_OutMemType.
XPK_OutHook (struct Hook *)
Hookfunc to accept (de)compressed data. See special chapter
on I/O hook functions.
IN ADDITION
XPK_OutBufLen (LONG)
The length of the output buffer you supply using XPK_OutBuf.
For decompression, must be decompressed size (see XpkExamine())
plus XPK_MARGIN. For compression, inlen+inlen/32+2*XPK_MARGIN.
XPK_GetOutLen (LONG *)
Stores the total length of the (de)compressed data in the
variable pointed to by ti_Data.
XPK_GetOutBufLen (LONG *)
Stores the length of the buffer allocated for the data in the
variable pointed to by ti_Data. FreeMem() the buffer you get
from XPK_GetOutBuf with the length you get from XPK_GetOutBufLen.
Note: For the number of bytes written, refer to XPK_GetOutLen!
XPK_OutMemType (LONG)
The type of memory to use for the output buffer.
You have to specify different input and output streams always. So it
produces wrong results, when you supply same buffer for XPK_InBuf and
XPK_OutBuf or same filehandle for XPK_InFH and XPK_OutFH.
PACKING TAGS
XPK_PackMethod (STRPTR)
Use indicated method for packing. This would be a four
letter string of uppercase characters and numbers.
XPK_PackMode (LONG)
Packing mode for sublib to use. Range is 0...100, where 100 is
most efficient.
XPK_StepDown (BOOL)
Reduce packing efficiency to save mem if necessary.
XPK_ChunkSize (LONG)
Chunk size to try to pack with. May be altered by the
master library.
XPK_LossyOK (BOOL)
Some packers, like MPEG, reduce the file size by deleting some
information. These information cannot be restored. This tag
tells xpkmaster.library if it is ok for you, that some
information is deleted. It is FALSE by default. Use it with
care! Should be used only with sound or picture files.
QUERY TAGS
XPK_PackersQuery (struct XpkPackerList *)
Returns an array of available packers names in the XpkPackerList
structure whose address is stored in the ti_Data field of this
tag.
XPK_PackerQuery (struct XpkPackerInfo *)
Returns information about one single packer in the XpkPackerInfo
structure whose address is stored in the ti_Data field of this
tag. See xpk/xpk.h for the meaning of the fields therein. You
must also supply XPK_PackMode.
XPK_ModeQuery (struct XpkMode *)
Returns information about one single packer mode in the XpkMode
structure whose address is stored in the ti_Data field of this
tag. See xpk/xpk.h for the meaning of the fields therein. The
data of xm_Next field is illegal and must not be used. You
must also supply XPK_PackMethod and optionally XPK_PackMode,
otherwise the default mode will be used.
OTHER TAGS
XPK_GetError (STRPTR)
Write error msg to the buffer passed. The buffer must be of
size XPKERRMSGSIZE. This tag calls XpkFault internally.
It is not recommended to use this tag any longer.
XPK_Password (STRPTR)
Use password for en- or decoding. Passing a NULL pointer or
zero length string is equivalent to omitting this tag.
XPK_Key16 (UWORD) (V4 REV25)
Supply a 16 bit key for decrunching of encrypted data. This
is only for decrunching of alien formats. XPK does not support
crunching with keys. Only know usage: crypted RNC files.
XPK_Key32 (ULONG) (V4 REV25)
Supply a 32 bit key for decrunching of encrypted data. This
is only for decrunching of alien formats. XPK does not support
crunching with keys. Currently no know usage.
XPK_ChunkHook (struct Hook *)
Hook function to call between chunks. Can print a progress
report, and if it returns a nonzero value, the (de)compression
will be aborted. See special chapter on chunk functions.
XPK_PassThru (BOOL)
If true, data will just be handed trough on decompression if they
were not packed. Otherwise you get XPKERR_NOTPACKED.
XPK_TaskPri (UBYTE)
The task priority to use during the (de)crunching. Use -1 for
background decompression.
XPK_FileName (STRPTR)
The name to print in the progress report. If none is given, the
InName will be used when packing and the OutName when unpacking.
PREFERENCES RELATED TAGS
XPK_UseXfdMaster (BOOL) (V4)
If TRUE, xfdmaster.library will be used for checking unknown
files. Useable with XpkUnpack() and XpkExamine(). Is FALSE by
default, but depends on preference settings.
XPK_UseExternals (BOOL) (V4)
If TRUE, xex libraries in LIBS:compressors/extern will be used
to check for crunched files. Useable with XpkUnpack() and
XpkExamine(). Default value is TRUE (depends on prefs!)
XPK_PassRequest (BOOL) (V4)
If this is set a requester will be used to query the user for a
password, if none is given. Useable with XpkPack(). This is
disabled by default, but can be overridden using preferences
settings.
XPK_Preferences (BOOL) (V4)
Tell xpkmaster.library whether to use its preferences system,
or not. This is enabled by default.
XPK_ChunkReport (BOOL) (V4)
If this tag is set, xpkmaster.library brings an automatic chunk
report request (when the preferences semaphore has a valid
function for that). This is disabled by default.
xpkmaster.library/--progress-- xpkmaster.library/--progress--
THE PROGRESS REPORT HOOK
The progress report function is a standard hook function that will
be called after every chunk (de)compressed. This will be about
every 30K, or just twice if the file format is not split in chunks.
If the field h_Entry in the hook is set, it will be called with
the hook itself in A0 and the progress report structure in A1.
If the progress report function returns a nonzero value,
(de)compression aborts.
NOTE: Because hooks are not called in program environment, they
cannot be used in small data model of some compilers, as register
A4 is not passed through. So the hook either has to be compiled in
large data model or should use __saveds keyword of some compilers.
xpkmaster.library/--data hooks-- xpkmaster.library/--data hooks--
GENERAL
You have four methods of passing data to xpkmaster.library: file-
names, filehandles, memory areas and hooks. The hooks are described
here. The hook field h_Entry has to be standard hook functions and
gets called with the hook itself in A0 and a pointer to a XpkIOMsg
in A1. Commands are stored in xiom_Type field, data in the other
fields. Return values are 0 or any of the XPKERR codes.
Commands XIO_FREE and XIO_ABORT may be ignored.
Whenever an error occurs, you have to return an XPKERR code and
stop work. You get a XIO_ABORT call in this case later. When no
error occured, return 0.
You may store private data in the free fields of XpkIOMsg structure.
You are always called with XIO_FREE or XIO_ABORT, so you can free
private stuff there. Buffers can be freed, when next time a buffer
allocation is required.
NOTE: Because hooks are not called in program environment, they
cannot be used in small data model of some compilers, as register
A4 is not passed through. So the hook either has to be compiled in
large data model or should use __saveds keyword of some compilers.
BUFFERS
Your hooks must be able to allocate buffers for read/write or pass
pointers to them, when they are already allocated. There are some
ways you have to handle this. First there is XIO_GETBUF. When getting
this command you have to pass a memory pointer pointing to a region
of at least xmm_Size size. For in hook there is another additionally
method. When XIO_READ is wanted and xiom_Ptr is zero, then you have
to pass (and allocate) a buf pointer and to fill it!
The buffers must be valid until you are next time asked to allocate
a buffer (either with XIO_GETBUF or XIO_READ). Then you may return
old buffer pointer (when memory is large enough) or allocate a new
buffer and free the old buffer. When XIO_ABORT or XIO_FREE is send
all your buffers should be freed.
NOTE: Your hooks do not get called only with your own buffers, but
also with xpkmaster internally buffers!
When your input data is already in memory, you may pass pointers
to your memory regions and need not to allocate new memory for
XIO_READ when pointer is zero. When xiom_Ptr is not zero for
XIO_READ, you have to copy the data.
Never expect, that you are called next time with buffer you
allocated. There may be write cycles of headers and other stuff
between XIO_GETBUF and XIO_WRITE. On reading it is equal.
COMMANDS
XIO_READ (in hooks only)
This command is called all time xpkmaster.library needs some data.
You have to fill the supplied memory area with input data of
needed size (not more!) When the input memory pointer is zero,
you have to allocate your own buffer and fill it. When you
allocated a buffer before (either by XIO_GETBUF or XIO_READ) you
can free it when pointer is zero.
Input: xiom_Size size of required data
xiom_Ptr already allocated buffer or zero
Output: xiom_Ptr pointer to memory area of xiom_Size
XIO_WRITE (out hooks only)
This function is called, when some data was compressed and should
be stored now. Copy the contents of buffer to your data storing
system.
Input: xiom_Size size of data
xiom_Ptr pointer to memory area of xiom_Size
Output: none
XIO_FREE (both)
You get this when work is finished, free all your stuff now.
Input: none
Output: none
XIO_ABORT (both)
You get this when work was aborted, because an error occured.
Free all your stuff now.
Input: none
Output: none
XIO_GETBUF (both)
Asks you to pass a needed buffer. This buffer is not freed by
xpkmaster.library. Do this when getting XIO_FREE, XIO_ABORT or
the next XIO_GETBUF. Input buffers may be freed too, when
XIO_READ is called with no pointer.
Input: xiom_Size size of necessary buffer
Output: xiom_Ptr pointer to the buffer
XIO_SEEK (both)
Change the current position in your data (like dos.library Seek
command). When you are not able to handle seek, all better
functions will fail. Pass XPKERR_NOFUNC in this case as return
value. The offset you have to seek is always relative to current
position. It can be negative too. Return value (xiom_Size) is
same as for dos.library Seek command.
Input: xiom_Size offset you have to seek
Output: xiom_Size buffer position before seek
XIO_TOTSIZE (both)
You either have to tell the total input data size (in hook) or get
told the total output data size (out hook).
OUT HOOK:
XIO_TOTSIZE may be ignored here. It tells you the maximum size
of output file (the real size may be shorter). This is for
example needed in memory hooks. This is only to inform you.
This command never needs to return an error code.
Input: xiom_Size total size of output data
Output: none
IN HOOK:
XIO_TOTSIZE cannot be ignored here. When your hook cannot
determine the total filesize, return any of the XPKERR values.
XIO_TOTSIZE is called only, when xpkmaster library really needs
filesize. Normal XPK files have size information in header and
XPK_InLen flags supplies information for input. In these cases
XIO_TOTSIZE is not used. But when returning an XPKERR, your hook
will not work in other cases, when size is required.
XIO_TOSIZE is used for following cases (when no XPK_InLen is
supplied!):
- decrunching of all non-xpk files
- crunching of files
NOTE: Only the size of the part, which should be processed, is
wanted. Most time this is from current position to end of file
(memory), but it may be shorter. But generally you have to
calculate size starting at current position.
Input: none
Output: xiom_Size total size of input data