diff options
Diffstat (limited to 'tests/ucomp.c')
-rw-r--r-- | tests/ucomp.c | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/tests/ucomp.c b/tests/ucomp.c new file mode 100644 index 0000000..cc3eef8 --- /dev/null +++ b/tests/ucomp.c @@ -0,0 +1,108 @@ + +/* + * Uncompress program this is very very fast + * + */ + +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <stdio.h> +#include <malloc.h> + +#define MAXLEN 255 + +#define maxno 61000U +#define USE_BSS + +#ifdef USE_BSS +unsigned char fptr[maxno]; +#else +unsigned char *fptr; +#endif +FILE * fd; +int key; + +main(argc, argv) +int argc; +char ** argv; +{ +#ifndef USE_BSS + fptr = (unsigned char * ) malloc(maxno); + + if( fptr == 0 ) + { + perror("Cannot allocate memory"); + exit(1); + } +#endif + + if( argc < 2 ) + { + fd = stdin; + key = getc(fd); + uncompress(); + } + else + { + fd = fopen(argv[1], "r" ); + if( fd == 0 ) { perror("Open failed"); exit(1); } + + key = getc(fd); + uncompress(); + } +} + +/* + + Uncompression routine -- v.v.fast +*/ + +uncompress() +{ + register unsigned char * mainscan; + register unsigned char * secondscan; + register unsigned char * ptr = (unsigned char * ) fptr; + register unsigned char * eptr = ptr+maxno; + register unsigned int len; + register int ch; + + mainscan = ptr; + + for(;;) + { + ch = getc(fd); + if(ch == EOF) break; + ch &= 0xFF; + if(ch == key) + { + ch = getc(fd); + if( ch == 0 ) + *mainscan++ = key; + else + { + len = (unsigned char) getc(fd); + if( ch & 0x80 ) + len += ((unsigned char) getc(fd)) << 8; + secondscan = mainscan - len; + if(len > mainscan - ptr) secondscan += maxno; + len = (unsigned char) ch & 0x7F; + for( ; len>0; len-- ) + { + *mainscan++ = *secondscan++; + if( secondscan == eptr ) secondscan = ptr; + if( mainscan == eptr ) + { write(1, ptr, (int)(mainscan-ptr)); mainscan = ptr; } + } + } + } + else + *mainscan++ = ch; + + if( mainscan == eptr ) + { write(1, ptr, (int)(mainscan-ptr)); mainscan = ptr; } + } + if( mainscan != ptr ) + { write(1, ptr, (int)(mainscan-ptr)); mainscan = ptr; } +} + |