amxmodx/compiler/libpc300/scexpand.c

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2005-07-24 20:00:55 +00:00
/* expand.c -- Byte Pair Encoding decompression */
/* Copyright 1996 Philip Gage */
/* Byte Pair Compression appeared in the September 1997
* issue of C/C++ Users Journal. The original source code
* may still be found at the web site of the magazine
* (www.cuj.com).
*
* The decompressor has been modified by me (Thiadmer
* Riemersma) to accept a string as input, instead of a
* complete file.
*/
#include <assert.h>
#include <stdio.h>
#include "sc.h"
#define STACKSIZE 16
SC_FUNC int strexpand(char *dest, unsigned char *source, int maxlen, unsigned char pairtable[128][2])
{
unsigned char stack[STACKSIZE];
short c, top = 0;
int len;
assert(maxlen > 0);
len = 1; /* already 1 byte for '\0' */
for (;;) {
/* Pop byte from stack or read byte from the input string */
if (top)
c = stack[--top];
else if ((c = *(unsigned char *)source++) == '\0')
break;
/* Push pair on stack or output byte to the output string */
if (c > 127) {
assert(top+2 <= STACKSIZE);
stack[top++] = pairtable[c-128][1];
stack[top++] = pairtable[c-128][0];
}
else {
len++;
if (maxlen > 1) { /* reserve one byte for the '\0' */
*dest++ = (char)c;
maxlen--;
}
}
}
*dest = '\0';
return len; /* return number of bytes decoded */
}
#if 0 /*for testing*/
#include "sc5.scp"
int main (int argc, char **argv)
{
int i;
char str[128];
for (i=0; i<58; i++) {
strexpand(str, errmsg[i], sizeof str, SCPACK_TABLE);
printf("%s", str);
} /* for */
return 0;
}
#endif