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- #include <stdio.h>
- #include <stdlib.h>
- #include <assert.h>
- #include "zlib.h"
- #define local static
- local void quit(char *why)
- {
- fprintf(stderr, "fitblk abort: %s\n", why);
- exit(1);
- }
- #define RAWLEN 4096
- local int partcompress(FILE *in, z_streamp def)
- {
- int ret, flush;
- unsigned char raw[RAWLEN];
- flush = Z_NO_FLUSH;
- do {
- def->avail_in = fread(raw, 1, RAWLEN, in);
- if (ferror(in))
- return Z_ERRNO;
- def->next_in = raw;
- if (feof(in))
- flush = Z_FINISH;
- ret = deflate(def, flush);
- assert(ret != Z_STREAM_ERROR);
- } while (def->avail_out != 0 && flush == Z_NO_FLUSH);
- return ret;
- }
- local int recompress(z_streamp inf, z_streamp def)
- {
- int ret, flush;
- unsigned char raw[RAWLEN];
- flush = Z_NO_FLUSH;
- do {
-
- inf->avail_out = RAWLEN;
- inf->next_out = raw;
- ret = inflate(inf, Z_NO_FLUSH);
- assert(ret != Z_STREAM_ERROR && ret != Z_DATA_ERROR &&
- ret != Z_NEED_DICT);
- if (ret == Z_MEM_ERROR)
- return ret;
-
- def->avail_in = RAWLEN - inf->avail_out;
- def->next_in = raw;
- if (inf->avail_out != 0)
- flush = Z_FINISH;
- ret = deflate(def, flush);
- assert(ret != Z_STREAM_ERROR);
- } while (ret != Z_STREAM_END && def->avail_out != 0);
- return ret;
- }
- #define EXCESS 256
- #define MARGIN 8
- int main(int argc, char **argv)
- {
- int ret;
- unsigned size;
- unsigned have;
- unsigned char *blk;
- unsigned char *tmp;
- z_stream def, inf;
-
- if (argc != 2)
- quit("need one argument: size of output block");
- ret = strtol(argv[1], argv + 1, 10);
- if (argv[1][0] != 0)
- quit("argument must be a number");
- if (ret < 8)
- quit("need positive size of 8 or greater");
- size = (unsigned)ret;
-
- blk = malloc(size + EXCESS);
- def.zalloc = Z_NULL;
- def.zfree = Z_NULL;
- def.opaque = Z_NULL;
- ret = deflateInit(&def, Z_DEFAULT_COMPRESSION);
- if (ret != Z_OK || blk == NULL)
- quit("out of memory");
-
- def.avail_out = size + EXCESS;
- def.next_out = blk;
- ret = partcompress(stdin, &def);
- if (ret == Z_ERRNO)
- quit("error reading input");
-
- if (ret == Z_STREAM_END && def.avail_out >= EXCESS) {
-
- have = size + EXCESS - def.avail_out;
- if (fwrite(blk, 1, have, stdout) != have || ferror(stdout))
- quit("error writing output");
-
- ret = deflateEnd(&def);
- assert(ret != Z_STREAM_ERROR);
- free(blk);
- fprintf(stderr,
- "%u bytes unused out of %u requested (all input)\n",
- size - have, size);
- return 0;
- }
-
- inf.zalloc = Z_NULL;
- inf.zfree = Z_NULL;
- inf.opaque = Z_NULL;
- inf.avail_in = 0;
- inf.next_in = Z_NULL;
- ret = inflateInit(&inf);
- tmp = malloc(size + EXCESS);
- if (ret != Z_OK || tmp == NULL)
- quit("out of memory");
- ret = deflateReset(&def);
- assert(ret != Z_STREAM_ERROR);
-
- inf.avail_in = size + EXCESS;
- inf.next_in = blk;
- def.avail_out = size + EXCESS;
- def.next_out = tmp;
- ret = recompress(&inf, &def);
- if (ret == Z_MEM_ERROR)
- quit("out of memory");
-
- ret = inflateReset(&inf);
- assert(ret != Z_STREAM_ERROR);
- ret = deflateReset(&def);
- assert(ret != Z_STREAM_ERROR);
-
- inf.avail_in = size - MARGIN;
- inf.next_in = tmp;
- def.avail_out = size;
- def.next_out = blk;
- ret = recompress(&inf, &def);
- if (ret == Z_MEM_ERROR)
- quit("out of memory");
- assert(ret == Z_STREAM_END);
-
- have = size - def.avail_out;
- if (fwrite(blk, 1, have, stdout) != have || ferror(stdout))
- quit("error writing output");
-
- free(tmp);
- ret = inflateEnd(&inf);
- assert(ret != Z_STREAM_ERROR);
- ret = deflateEnd(&def);
- assert(ret != Z_STREAM_ERROR);
- free(blk);
- fprintf(stderr,
- "%u bytes unused out of %u requested (%lu input)\n",
- size - have, size, def.total_in);
- return 0;
- }
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