/*  Pawn compiler

 *

 *  Routines to maintain a "text file" in memory.

 *

 *  Copyright (c) ITB CompuPhase, 2003-2006

 *

 *  This software is provided 'as-is', without any express or implied warranty.

 *  In no event will the authors be held liable for any damages arising from the

 *  use of this software.

 *

 *  Permission is granted to anyone to use this software for any purpose,

 *  including commercial applications, and to alter it and redistribute it

 *  freely, subject to the following restrictions:

 *

 *  1. The origin of this software must not be misrepresented; you must not

 *     claim that you wrote the original software. If you use this software in

 *     a product, an acknowledgment in the product documentation would be

 *     appreciated but is not required.

 *

 *  2. Altered source versions must be plainly marked as such, and must not be

 *     misrepresented as being the original software.

 *

 *  3. This notice may not be removed or altered from any source distribution.

 *

 *  Version: $Id$

 */

#include <assert.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "memfile.h"

#if defined FORTIFY

  #include <alloc/fortify.h>

#endif

typedef memfile_t MEMFILE;

#define tMEMFILE  1

#include "sc.h"

MEMFILE *mfcreate(const char *filename)

{

  return memfile_creat(filename, 4096);

}

void mfclose(MEMFILE *mf)

{

  memfile_destroy(mf);

}

int mfdump(MEMFILE *mf)

{

  FILE *fp;

  int okay;

  assert(mf!=NULL);

  /* create the file */

  fp=fopen(mf->name, "wb");

  if (fp==NULL)

    return 0;

  okay=1;

  okay = okay & (fwrite(mf->base, mf->usedoffs, 1, fp)==(size_t)mf->usedoffs);

  fclose(fp);

  return okay;

}

long mflength(const MEMFILE *mf)

{

  return mf->usedoffs;

}

long mfseek(MEMFILE *mf,long offset,int whence)

{

  long length;

  assert(mf!=NULL);

  if (mf->usedoffs == 0)

    return 0L;          /* early exit: not a single byte in the file */

  /* find the size of the memory file */

  length=mflength(mf);

  /* convert the offset to an absolute position */

  switch (whence) {

  case SEEK_SET:

    break;

  case SEEK_CUR:

    offset+=mf->offs;

    break;

  case SEEK_END:

    assert(offset<=0);

    offset+=length;

    break;

  } /* switch */

  /* clamp to the file length limit */

  if (offset<0)

    offset=0;

  else if (offset>length)

    offset=length;

  /* set new position and return it */

  memfile_seek(mf, offset);

  return offset;

}

unsigned int mfwrite(MEMFILE *mf,const unsigned char *buffer,unsigned int size)

{

  return (memfile_write(mf, buffer, size) ? size : 0);

}

unsigned int mfread(MEMFILE *mf,unsigned char *buffer,unsigned int size)

{

  return memfile_read(mf, buffer, size);

}

char *mfgets(MEMFILE *mf,char *string,unsigned int size)

{

  char *ptr;

  unsigned int read;

  long seek;

  assert(mf!=NULL);

  read=mfread(mf,(unsigned char *)string,size);

  if (read==0)

    return NULL;

  seek=0L;

  /* make sure that the string is zero-terminated */

  assert(read<=size);

  if (read<size) {

    string[read]='\0';

  } else {

    string[size-1]='\0';

    seek=-1;            /* undo reading the character that gets overwritten */

  } /* if */

  /* find the first '\n' */

  ptr=strchr(string,'\n');

  if (ptr!=NULL) {

    *(ptr+1)='\0';

    seek=(long)(ptr-string)+1-(long)read;

  } /* if */

  /* undo over-read */

  assert(seek<=0);      /* should seek backward only */

  if (seek!=0)

    mfseek(mf,seek,SEEK_CUR);

  return string;

}

int mfputs(MEMFILE *mf,const char *string)

{

  unsigned int written,length;

  assert(mf!=NULL);

  length=strlen(string);

  written=mfwrite(mf,(unsigned char *)string,length);

  return written==length;

}