amxmodx/compiler/libpc300/scmemfil.c

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7.6 KiB
C
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2005-07-25 00:00:55 +04:00
/* Pawn compiler
*
* Routines to maintain a "text file" in memory.
*
* Copyright (c) ITB CompuPhase, 2003-2005
*
* 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>
#if defined FORTIFY
#include "fortify.h"
#endif
#define BUFFERSIZE 512u
/* For every block, except the first:
* buffer points to a block that is BUFFERSIZE long that holds the data
* bufpos is the "used size" of the block
* For the first block:
* buffer points to the "file name"
* bufpos is the current "file pointer"
*/
typedef struct tagMEMFILE {
struct tagMEMFILE *next;
unsigned char *buffer;
long bufpos;
} MEMFILE;
#define tMEMFILE 1
#include "sc.h"
MEMFILE *mfcreate(char *filename)
{
MEMFILE *mf;
/* create a first block that only holds the name */
mf=(MEMFILE*)malloc(sizeof(MEMFILE));
if (mf==NULL)
return NULL;
memset(mf,0,sizeof(MEMFILE));
mf->buffer=(unsigned char*)strdup(filename);
if (mf->buffer==NULL) {
free(mf);
return NULL;
} /* if */
return mf;
}
void mfclose(MEMFILE *mf)
{
MEMFILE *next;
assert(mf!=NULL);
while (mf!=NULL) {
next=mf->next;
assert(mf->buffer!=NULL);
free(mf->buffer);
free(mf);
mf=next;
} /* while */
}
int mfdump(MEMFILE *mf)
{
FILE *fp;
int okay;
assert(mf!=NULL);
/* create the file */
fp=fopen((char*)mf->buffer,"wb");
if (fp==NULL)
return 0;
okay=1;
mf=mf->next;
while (mf!=NULL) {
assert(mf->buffer!=NULL);
/* all blocks except the last should be fully filled */
assert(mf->next==NULL || (unsigned long)mf->bufpos==BUFFERSIZE);
okay=okay && fwrite(mf->buffer,1,(size_t)mf->bufpos,fp)==(size_t)mf->bufpos;
mf=mf->next;
} /* while */
fclose(fp);
return okay;
}
long mflength(MEMFILE *mf)
{
long length;
assert(mf!=NULL);
/* find the size of the memory file */
length=0L;
mf=mf->next; /* skip initial block */
while (mf!=NULL) {
assert(mf->next==NULL || (unsigned long)mf->bufpos==BUFFERSIZE);
length+=mf->bufpos;
mf=mf->next;
} /* while */
return length;
}
long mfseek(MEMFILE *mf,long offset,int whence)
{
long length;
assert(mf!=NULL);
if (mf->next==NULL)
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->bufpos;
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 */
mf->bufpos=offset;
return offset;
}
unsigned int mfwrite(MEMFILE *mf,unsigned char *buffer,unsigned int size)
{
long length;
long numblocks;
int blockpos,blocksize;
unsigned int bytes;
MEMFILE *block;
assert(mf!=NULL);
/* see whether more memory must be allocated */
length=mflength(mf);
assert(mf->bufpos>=0 && mf->bufpos<=length);
numblocks=(length+BUFFERSIZE-1)/BUFFERSIZE; /* # allocated blocks */
while (mf->bufpos+size>numblocks*BUFFERSIZE) {
/* append a block */
MEMFILE *last;
block=(MEMFILE*)malloc(sizeof(MEMFILE));
if (block==NULL)
return 0;
memset(block,0,sizeof(MEMFILE));
block->buffer=(unsigned char*)malloc(BUFFERSIZE);
if (block->buffer==NULL) {
free(block);
return 0;
} /* if */
for (last=mf; last->next!=NULL; last=last->next)
/* nothing */;
assert(last!=NULL);
assert(last->next==NULL);
last->next=block;
numblocks++;
} /* while */
if (size==0)
return 0;
/* find the block to start writing to */
numblocks=mf->bufpos/BUFFERSIZE; /* # blocks to skip */
block=mf->next;
while (numblocks-->0) {
assert(block!=NULL);
block=block->next;
} /* while */
assert(block!=NULL);
/* copy into memory */
bytes=0;
blockpos=(int)(mf->bufpos % BUFFERSIZE);
do {
blocksize=BUFFERSIZE-blockpos;
assert(blocksize>=0);
if ((unsigned int)blocksize>size)
blocksize=size;
assert(block!=NULL);
memcpy(block->buffer+blockpos,buffer,blocksize);
buffer+=blocksize;
size-=blocksize;
bytes+=blocksize;
if (blockpos+blocksize>block->bufpos)
block->bufpos=blockpos+blocksize;
assert(block->bufpos>=0 && (unsigned long)block->bufpos<=BUFFERSIZE);
block=block->next;
blockpos=0;
} while (size>0);
/* adjust file pointer */
mf->bufpos+=bytes;
return bytes;
}
unsigned int mfread(MEMFILE *mf,unsigned char *buffer,unsigned int size)
{
long length;
long numblocks;
int blockpos,blocksize;
unsigned int bytes;
MEMFILE *block;
assert(mf!=NULL);
/* adjust the size to read */
length=mflength(mf);
assert(mf->bufpos>=0 && mf->bufpos<=length);
if (mf->bufpos+size>(unsigned long)length)
size=(int)(length-mf->bufpos);
assert(mf->bufpos+size<=(unsigned long)length);
if (size==0)
return 0;
/* find the block to start reading from */
numblocks=mf->bufpos/BUFFERSIZE; /* # blocks to skip */
block=mf->next;
while (numblocks-->0) {
assert(block!=NULL);
block=block->next;
} /* while */
assert(block!=NULL);
/* copy out of memory */
bytes=0;
blockpos=(int)(mf->bufpos % BUFFERSIZE);
do {
blocksize=BUFFERSIZE-blockpos;
if ((unsigned int)blocksize>size)
blocksize=size;
assert(block!=NULL);
assert(block->bufpos>=0 && (unsigned long)block->bufpos<=BUFFERSIZE);
assert(blockpos+blocksize<=block->bufpos);
memcpy(buffer,block->buffer+blockpos,blocksize);
buffer+=blocksize;
size-=blocksize;
bytes+=blocksize;
block=block->next;
blockpos=0;
} while (size>0);
/* adjust file pointer */
mf->bufpos+=bytes;
return bytes;
}
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,char *string)
{
unsigned int written,length;
assert(mf!=NULL);
length=strlen(string);
written=mfwrite(mf,(unsigned char *)string,length);
return written==length;
}