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gzip cleanup part #11

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This commit is contained in:
Denis Vlasenko 2007-01-07 19:44:35 +00:00
parent 56c83eaaf5
commit 2f6df7fa0a
1 changed files with 33 additions and 12 deletions
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45
archival/gzip.c
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@ -16,6 +16,22 @@
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
/* big objects in bss:
* 00000020 b bl_count
* 00000074 b base_length
* 00000078 b base_dist
* 00000078 b static_dtree
* 0000009c b bl_tree
* 000000f4 b dyn_dtree
* 00000100 b length_code
* 00000200 b dist_code
* 0000023d b depth
* 00000400 b flag_buf
* 00000480 b static_ltree
* 000008f4 b dyn_ltree
* 000008f4 b heap
*/
/* TODO: full support for -v for DESKTOP
/usr/bin/gzip -v a bogus aa
a: 85.1% -- replaced with a.gz
@ -329,7 +345,7 @@ static int foreground; /* set if program run in foreground */
static int method = DEFLATED; /* compression method */
static int exit_code; /* program exit code */
static long time_stamp; /* original time stamp (modification time) */
static char z_suffix[MAX_SUFFIX + 1]; /* default suffix (can be set with --suffix) */
////static char z_suffix[MAX_SUFFIX + 1]; /* default suffix (can be set with --suffix) */
static int ifd; /* input file descriptor */
static int ofd; /* output file descriptor */
@ -1046,7 +1062,7 @@ static int base_dist[D_CODES];
/* DECLARE(ush, d_buf, DIST_BUFSIZE); buffer for distances */
static uch flag_buf[(LIT_BUFSIZE / 8)];
static uch flag_buf[LIT_BUFSIZE / 8];
/* flag_buf is a bit array distinguishing literals from lengths in
* l_buf, thus indicating the presence or absence of a distance.
@ -1130,6 +1146,7 @@ static void init_block(void)
* Allocate the match buffer, initialize the various tables and save the
* location of the internal file attribute (ascii/binary) and method
* (DEFLATE/STORE).
* One callsite in zip()
*/
static void ct_init(ush * attr, int *methodp)
{
@ -1143,8 +1160,10 @@ static void ct_init(ush * attr, int *methodp)
file_method = methodp;
compressed_len = 0L;
#ifdef NOT_NEEDED
if (static_dtree[0].Len != 0)
return; /* ct_init already called */
#endif
/* Initialize the mapping length (0..255) -> length code (0..28) */
length = 0;
@ -1174,14 +1193,15 @@ static void ct_init(ush * attr, int *methodp)
for (; code < D_CODES; code++) {
base_dist[code] = dist << 7;
for (n = 0; n < (1 << (extra_dbits[code] - 7)); n++) {
dist_code[256 + dist++] = (uch) code;
dist_code[256 + dist++] = code;
}
}
Assert(dist == 256, "ct_init: 256+dist != 512");
/* Construct the codes of the static literal tree */
/* already zeroed - it's in bss
for (bits = 0; bits <= MAX_BITS; bits++)
bl_count[bits] = 0;
bl_count[bits] = 0; */
n = 0;
while (n <= 143) {
@ -1478,7 +1498,7 @@ static void build_tree(tree_desc * desc)
/* Create a new node father of n and m */
tree[node].Freq = tree[n].Freq + tree[m].Freq;
depth[node] = (uch) (MAX(depth[n], depth[m]) + 1);
depth[node] = MAX(depth[n], depth[m]) + 1;
tree[n].Dad = tree[m].Dad = (ush) node;
#ifdef DUMP_BL_TREE
if (tree == bl_tree) {
@ -1524,14 +1544,15 @@ static void scan_tree(ct_data * tree, int max_code)
max_count = 138;
min_count = 3;
}
tree[max_code + 1].Len = (ush) 0xffff; /* guard */
tree[max_code + 1].Len = 0xffff; /* guard */
for (n = 0; n <= max_code; n++) {
curlen = nextlen;
nextlen = tree[n + 1].Len;
if (++count < max_count && curlen == nextlen) {
if (++count < max_count && curlen == nextlen)
continue;
} else if (count < min_count) {
if (count < min_count) {
bl_tree[curlen].Freq += count;
} else if (curlen != 0) {
if (curlen != prevlen)
@ -1544,15 +1565,15 @@ static void scan_tree(ct_data * tree, int max_code)
}
count = 0;
prevlen = curlen;
max_count = 7;
min_count = 4;
if (nextlen == 0) {
max_count = 138;
min_count = 3;
} else if (curlen == nextlen) {
max_count = 6;
min_count = 3;
} else {
max_count = 7;
min_count = 4;
}
}
}
@ -2152,7 +2173,7 @@ int gzip_main(int argc, char **argv)
}
#endif
strncpy(z_suffix, ".gz", sizeof(z_suffix) - 1);
//// strncpy(z_suffix, ".gz", sizeof(z_suffix) - 1);
/* Allocate all global buffers (for DYN_ALLOC option) */
ALLOC(uch, inbuf, INBUFSIZ + INBUF_EXTRA);