CD Actual 15/CDACTUAL15.iso/cdactual/program/c/WLIB.ZIP/WFILE.H

C/C++ Source or Header | 1993-03-12 | 10.4 KB | 294 lines

#ifndef WFileIncluded
#define WFileIncluded

// copyright (c) 1992, 1993 by Paul Wheaton
// 1916 Brooks #205, Missoula, MT  59801
//
// voice phone:  [phone]
// modem phone:  [phone] (2400N81)
//  CompuServe:  72707,207
//    Internet:  [e-mail]

/*

Although these routines lean on ANSI stdio functions, many of them work
somewhat differently.   "File" is for binary mode and "TextFile" is for
text mode. The constructor will open the file (create it if it doesn't
exist).  It is the applications programmers responsibility to make sure
that the filename given is valid and possible.  If the file cannot be
opened, the program will be stopped.

Binary files:

Reading and writing may be done to any byte location that will fit into a
long.  Writing more than a byte beyond the EOF will simply generate garbage
characters from the EOF up to the point you are now writing.  Reading
beyond EOF will result in a garbage read and the Read function will return
False.

Text files:

After opening, the first read will be done from the beginning of the file
and the first write will be done to the end of the file.

Note!: if a special buffer size has been requested and *denied* (due to
lack of heap space), a beep will sound but file access will continue
with the default buffer size.

*/

#include <stdio.h>
#include <io.h>
#include <WMisc.h>
#include <WVec.h>

#ifdef MAJORBBS

  Bool FileExists(const char*);

#else

  #define FileExists(FileName) (!access(FileName,0))
    // returns True if the file exists

#endif


char CurDiskDrive();

long DiskSpace(const char Drive='.');  // '.' means default drive
  // the value returned is in "K" or "kilobytes" or number of 1024 byte blocks
  // this is in case this library is on a computer that can handle capacity
  // of more than 2 gigs that a "long" could represent.

long FileSize(const char* FileName);
  // the value returned is in bytes

#define WriteThing(A) Write(&A,sizeof(A))
#define ReadThing(A) Read(&A,sizeof(A))
  // use only on things where the size can be properly determined with
  // "sizeof".  Use only with "File" not "TextFile"

void DeleteFile(const char* FileName);
  // if the file is deletable, it's deleted

const ReadAndWrite=0;
const ReadOnly=1;

//enum FileShareType {xxx};

class LowLevelFile
  {
      FILE* FilePointer;
      Bool Open;
      char* GivenFileName;
      char* Buf; // for future use to change the size of the buffer
      void InternalInit(int);
      friend class File;
      friend class TextFile;
      friend class RecFileRef;
      friend class RecFile;
    public:
      LowLevelFile(const char* FileName,const char* Mode, int BufSize);
      //LowLevelFile(const char* FileName,int Share,const char* Mode, int BufSize);
      ~LowLevelFile() {Close();}
      void Close();  // you can close the file early if you want
      void Flush() {fflush(FilePointer);}
        // flush your write buffers out to disk
      long CurPos() {return ftell(FilePointer);}
        // current file position:  where you are about to write to or read from
      void Seek(long Offset) {fseek(FilePointer,Offset,0);}
      void SeekBOF(){fseek(FilePointer,0,0);}
      void SeekEOF(){fseek(FilePointer,0,2);}
      long Size();  //  the file size in bytes
      Bool EndOfFile() {return feof(FilePointer);}
      #ifdef MAJORBBS
        void* operator new(size_t size){return malloc(size);}
        void  operator delete(void* p) {free(p);}
      #endif
  };

class File:public LowLevelFile
  {
    public:
      File(const char* FileName,Bool Mode=ReadAndWrite,int BufSize=BUFSIZ);
      Bool Read(void *Buffer,int Size=1);
      Bool Read(ByteVector& BV,int Size=1);
      void Write(const void *Buffer,int Size=1);
  };

class RecFile:public LowLevelFile
  {
      int RecSize;
    public:
      RecFile(const char* FileName,int RecordSize,Bool Mode,int BufSize);
      Bool Read(void *Buffer);
      Bool Read(void *Buffer,int Quan);
      void Seek(long RecNum);
      long CurRec();  // record number
      long Size();  // number of recs
      void Write(const void *Buffer);
      void Write(const void *Buffer,int Quan);
  };

#define CreateRecFileClass(ClassName,StructType)                        \
                                                                        \
class ClassName;                                                        \
                                                                        \
class ClassName ## Ref                                                  \
  {                                                                     \
      ClassName* F;                                                     \
      ClassName ## Ref(ClassName* XF){F=XF;}                            \
      friend class ClassName;                                           \
    public:                                                             \
      void operator=(const StructType& X);                              \
      operator StructType();                                            \
      void* operator new(size_t size){return malloc(size);}             \
      void  operator delete(void* p) {free(p);}                         \
  };                                                                    \
                                                                        \
class ClassName:public RecFile                                          \
  {                                                                     \
    public:                                                             \
      ClassName(const char* FileName,Bool Mode=ReadAndWrite,            \
          int BufSize=BUFSIZ):                                          \
          RecFile(FileName,sizeof(StructType),Mode,BufSize){}           \
      Bool Read(StructType& X){return RecFile::Read(&X);}               \
      Bool Read(StructType* X,int Q){return RecFile::Read(X,Q);}        \
      void Write(const StructType& X){RecFile::Write(&X);}              \
      void Write(const StructType* X,int Q){RecFile::Write(X,Q);}       \
      ClassName ## Ref operator[](long RecNum)                          \
        {Seek(RecNum); return ClassName ## Ref(this);}                  \
  };                                                                    \
                                                                        \
inline void ClassName ## Ref::operator=(const StructType& X)            \
  {F->Write(X);}                                                        \
inline void ClassName ## Ref::operator StructType()                     \
  {StructType X; F->Read(X); return X;}


// friend void operator=(StructType& X,ClassName ## Ref R);          \
//inline void operator=(StructType& X,ClassName ## Ref R)                 \
//  {(R.F)->Read(X);}

#ifdef __BORLANDC__
  #define FTMRO "rt"
  #define FTMRW "r+t"
#else
  #define FTMRO "r"
  #define FTMRW "r+"
#endif

class TextFile:public LowLevelFile
  {
      Bool Started;  // used to figure out whether we're starting off appending or reading
    public:
      TextFile(const char* FileName,Bool Mode=ReadAndWrite,int BufSize=BUFSIZ):
          LowLevelFile(FileName,((Mode==ReadOnly)?(FTMRO):(FTMRW)),BufSize)
          {Started=False;}
      void Seek(long Offset) {Started=True; LowLevelFile::Seek(Offset);}
      Bool Read(char* S);
      void Write(const char* S);
      void WriteLine(const char* S="");
  };

void FileCopying(File& DestFile, File& SourceFile, long Size);
  // will not modify file positions before writing

void CopyFile(const char* DestFile, const char* SourceFile);
  // source file must be created.  if dest file already exists,
  // it will be deleted

Word CRC(File& F,long FSize);  // CRC of file starting at current pos
Word CRC(File& F);  // CRC of entire file


/*

Example of a file of records:

struct XType
  {
    long a,b,c;
  };

CreateRecFileClass(XFile,XType);

main()
  {
    XType X;
    XFile F("X.BIN");
    F[0]=X;
    X=F[0];
  }

*/

/*
  Features to add:
     1)  Make it so that a person cannot write beyond the end of their block

*/

class TokenFile: public File
  {
      Word MaxTokens;
      long FirstFreeBlock;
      void GetFreeInfo(long Pos, long& Size, long& NextBlock);
        // used to traverse free list
      long New(long FSize);
        // returns a block number that can hold "FSize" and updates the
        // free list if needed
      void Delete(long Pos, long Size);
        // adds this info to the free list if its big enough
      void SeekIndexSlot(Word Token) {File::Seek(Token*8);}
      void ReadCurIndexSlot(long& Pos, long& Size);
      friend Bool TokenExists(const char*,Word);
      friend void ShowFreeList(const char*);
    public:
      TokenFile(const char* FileName, int BufSize=BUFSIZ);
      long Seek(Word Token);
        /*  returns the size of your object (0 if it doesn't exist).  If
        object is found, file pointer is moved to your objects storage
        location.  You may then read your data with any binary file type
        read.  There will be nothing to stop you from reading too much */
      void WritePrep(Word Token,long DataSize);
        /* sets up Token with a data area of just the right size.  Any
        previous data under that Token is deleted.  File pointer is left
        where writing may begin */
      void Delete(Word Token);
        // makes the space that was taken by Token's object available
      Word MaxToken(){return MaxTokens;}
      Bool TokenExists(Word Token);
      void Extract(Word Token,char* FileName);
  };

Bool TokenExists(const char* FileName, Word Token);

void SaveBootRec(TokenFile& F,const char* CName);
  // Optional...  Saves the video device boot info

/* This class inherits all of the properties of the (binary) File class.
It adds the feature of being able to store many little files into one
larger file.  Given a token ("access code", "key") value you may store and
retrieve your data pretty much like any other binary file.

Example of writing a struct of type XType:

   XType X;
   TokenFile F("DATA.BIN");
   F.WritePrep(326,sizeof(X)); // you pick your own Token number and object size
   F.WriteThing(X);

Example of reading the same struct:

   XType X;
   TokenFile F("DATA.BIN");
   if (F.Seek(326)) F.ReadThing(X);
   else FatalError("cannot find my X thing in file DATA.BIN");

*/


#endif