mirror of
https://github.com/sheumann/hush.git
synced 2024-12-22 14:30:31 +00:00
gzip cleanup part #9
This commit is contained in:
Denis Vlasenko
parent
52933d47bd
commit
89af56b3e5
189
archival/gzip.c
189
archival/gzip.c
@ -67,6 +67,7 @@ aa: 85.1% -- replaced with aa.gz
|
||||
# endif
|
||||
#endif
|
||||
|
||||
//remove??
|
||||
#define INBUF_EXTRA 64 /* required by unlzw() */
|
||||
|
||||
#ifndef OUTBUFSIZ
|
||||
@ -76,6 +77,7 @@ aa: 85.1% -- replaced with aa.gz
|
||||
# define OUTBUFSIZ 16384 /* output buffer size */
|
||||
# endif
|
||||
#endif
|
||||
//remove??
|
||||
#define OUTBUF_EXTRA 2048 /* required by unlzw() */
|
||||
|
||||
#ifndef DIST_BUFSIZE
|
||||
@ -166,15 +168,6 @@ aa: 85.1% -- replaced with aa.gz
|
||||
/* For portability to 16 bit machines, do not use values above 15. */
|
||||
#endif
|
||||
|
||||
/* To save space (see unlzw.c), we overlay prev+head with tab_prefix and
|
||||
* window with tab_suffix. Check that we can do this:
|
||||
*/
|
||||
#if (WSIZE<<1) > (1<<BITS)
|
||||
# error cannot overlay window with tab_suffix and prev with tab_prefix0
|
||||
#endif
|
||||
#if HASH_BITS > BITS-1
|
||||
# error cannot overlay head with tab_prefix1
|
||||
#endif
|
||||
#define HASH_SIZE (unsigned)(1<<HASH_BITS)
|
||||
#define HASH_MASK (HASH_SIZE-1)
|
||||
#define WMASK (WSIZE-1)
|
||||
@ -213,26 +206,6 @@ typedef unsigned IPos;
|
||||
array = NULL; \
|
||||
}
|
||||
|
||||
/* DECLARE(uch, window, 2L*WSIZE); */
|
||||
/* Sliding window. Input bytes are read into the second half of the window,
|
||||
* and move to the first half later to keep a dictionary of at least WSIZE
|
||||
* bytes. With this organization, matches are limited to a distance of
|
||||
* WSIZE-MAX_MATCH bytes, but this ensures that IO is always
|
||||
* performed with a length multiple of the block size. Also, it limits
|
||||
* the window size to 64K, which is quite useful on MSDOS.
|
||||
* To do: limit the window size to WSIZE+BSZ if SMALL_MEM (the code would
|
||||
* be less efficient).
|
||||
*/
|
||||
|
||||
/* DECLARE(Pos, prev, WSIZE); */
|
||||
/* Link to older string with same hash index. To limit the size of this
|
||||
* array to 64K, this link is maintained only for the last 32K strings.
|
||||
* An index in this array is thus a window index modulo 32K.
|
||||
*/
|
||||
|
||||
/* DECLARE(Pos, head, 1<<HASH_BITS); */
|
||||
/* Heads of the hash chains or 0. */
|
||||
|
||||
static long block_start;
|
||||
|
||||
/* window position at the beginning of the current output block. Gets
|
||||
@ -300,7 +273,6 @@ enum {
|
||||
|
||||
|
||||
/* ===========================================================================
|
||||
* Prototypes for local functions.
|
||||
*/
|
||||
static void fill_window(void);
|
||||
|
||||
@ -311,41 +283,59 @@ static void check_match(IPos start, IPos match, int length);
|
||||
#endif
|
||||
|
||||
|
||||
/* from deflate.c */
|
||||
static void lm_init(ush * flags);
|
||||
static ulg deflate(void);
|
||||
|
||||
/* from trees.c */
|
||||
static void ct_init(ush * attr, int *methodp);
|
||||
static int ct_tally(int dist, int lc);
|
||||
static ulg flush_block(char *buf, ulg stored_len, int eof);
|
||||
|
||||
/* from bits.c */
|
||||
static void bi_init(int zipfile);
|
||||
static void send_bits(int value, int length);
|
||||
static unsigned bi_reverse(unsigned value, int length);
|
||||
static void bi_windup(void);
|
||||
static void copy_block(char *buf, unsigned len, int header);
|
||||
|
||||
/* global buffers */
|
||||
|
||||
/* To save memory for 16 bit systems, some arrays are overlaid between
|
||||
* the various modules:
|
||||
* deflate: prev+head window d_buf l_buf outbuf
|
||||
* unlzw: tab_prefix tab_suffix stack inbuf outbuf
|
||||
//remove unlzw??
|
||||
* For compression, input is done in window[]. For decompression, output
|
||||
* is done in window except for unlzw.
|
||||
*/
|
||||
/* To save space (see unlzw.c), we overlay prev+head with tab_prefix and
|
||||
* window with tab_suffix. Check that we can do this:
|
||||
*/
|
||||
#if (WSIZE<<1) > (1<<BITS)
|
||||
# error cannot overlay window with tab_suffix and prev with tab_prefix0
|
||||
#endif
|
||||
#if HASH_BITS > BITS-1
|
||||
# error cannot overlay head with tab_prefix1
|
||||
#endif
|
||||
|
||||
#define tab_suffix window
|
||||
#define tab_prefix prev /* hash link (see deflate.c) */
|
||||
//#define tab_suffix window
|
||||
//#define tab_prefix prev /* hash link (see deflate.c) */
|
||||
#define head (prev+WSIZE) /* hash head (see deflate.c) */
|
||||
|
||||
DECLARE(uch, inbuf, INBUFSIZ + INBUF_EXTRA);
|
||||
/* DECLARE(uch, window, 2L*WSIZE); */
|
||||
/* Sliding window. Input bytes are read into the second half of the window,
|
||||
* and move to the first half later to keep a dictionary of at least WSIZE
|
||||
* bytes. With this organization, matches are limited to a distance of
|
||||
* WSIZE-MAX_MATCH bytes, but this ensures that IO is always
|
||||
* performed with a length multiple of the block size. Also, it limits
|
||||
* the window size to 64K, which is quite useful on MSDOS.
|
||||
* To do: limit the window size to WSIZE+BSZ if SMALL_MEM (the code would
|
||||
* be less efficient).
|
||||
*/
|
||||
|
||||
/* DECLARE(Pos, prev, WSIZE); */
|
||||
/* Link to older string with same hash index. To limit the size of this
|
||||
* array to 64K, this link is maintained only for the last 32K strings.
|
||||
* An index in this array is thus a window index modulo 32K.
|
||||
*/
|
||||
|
||||
/* DECLARE(Pos, head, 1<<HASH_BITS); */
|
||||
/* Heads of the hash chains or 0. */
|
||||
|
||||
DECLARE(uch, inbuf, INBUFSIZ + INBUF_EXTRA); //remove + XX_EXTRA (unlzw)??
|
||||
DECLARE(uch, outbuf, OUTBUFSIZ + OUTBUF_EXTRA);
|
||||
DECLARE(ush, d_buf, DIST_BUFSIZE);
|
||||
DECLARE(uch, window, 2L * WSIZE);
|
||||
DECLARE(ush, tab_prefix, 1L << BITS);
|
||||
DECLARE(ush, prev, 1L << BITS);
|
||||
|
||||
static long isize; /* number of input bytes */
|
||||
|
||||
@ -544,11 +534,12 @@ static unsigned bi_reverse(unsigned code, int len)
|
||||
{
|
||||
unsigned res = 0;
|
||||
|
||||
do {
|
||||
while (1) {
|
||||
res |= code & 1;
|
||||
code >>= 1, res <<= 1;
|
||||
} while (--len > 0);
|
||||
return res >> 1;
|
||||
if (--len <= 0) return res;
|
||||
code >>= 1;
|
||||
res <<= 1;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
@ -957,14 +948,11 @@ static ulg deflate(void)
|
||||
* terms of the GNU General Public License, see the file COPYING.
|
||||
*/
|
||||
|
||||
/*
|
||||
* PURPOSE
|
||||
*
|
||||
/* PURPOSE
|
||||
* Encode various sets of source values using variable-length
|
||||
* binary code trees.
|
||||
*
|
||||
* DISCUSSION
|
||||
*
|
||||
* The PKZIP "deflation" process uses several Huffman trees. The more
|
||||
* common source values are represented by shorter bit sequences.
|
||||
*
|
||||
@ -976,7 +964,6 @@ static ulg deflate(void)
|
||||
* (APPNOTE.TXT) distributed as part of PKWARE's PKZIP program.
|
||||
*
|
||||
* REFERENCES
|
||||
*
|
||||
* Lynch, Thomas J.
|
||||
* Data Compression: Techniques and Applications, pp. 53-55.
|
||||
* Lifetime Learning Publications, 1985. ISBN 0-534-03418-7.
|
||||
@ -990,7 +977,6 @@ static ulg deflate(void)
|
||||
* Addison-Wesley, 1983. ISBN 0-201-06672-6.
|
||||
*
|
||||
* INTERFACE
|
||||
*
|
||||
* void ct_init(ush *attr, int *methodp)
|
||||
* Allocate the match buffer, initialize the various tables and save
|
||||
* the location of the internal file attribute (ascii/binary) and
|
||||
@ -1003,7 +989,6 @@ static ulg deflate(void)
|
||||
* Determine the best encoding for the current block: dynamic trees,
|
||||
* static trees or store, and output the encoded block to the zip
|
||||
* file. Returns the total compressed length for the file so far.
|
||||
*
|
||||
*/
|
||||
|
||||
/* ===========================================================================
|
||||
@ -1037,20 +1022,20 @@ static ulg deflate(void)
|
||||
typedef uch extra_bits_t;
|
||||
|
||||
/* extra bits for each length code */
|
||||
static const extra_bits_t extra_lbits[LENGTH_CODES]
|
||||
= { 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4,
|
||||
static const extra_bits_t extra_lbits[LENGTH_CODES]= {
|
||||
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4,
|
||||
4, 4, 5, 5, 5, 5, 0
|
||||
};
|
||||
|
||||
/* extra bits for each distance code */
|
||||
static const extra_bits_t extra_dbits[D_CODES]
|
||||
= { 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9,
|
||||
static const extra_bits_t extra_dbits[D_CODES] = {
|
||||
0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9,
|
||||
10, 10, 11, 11, 12, 12, 13, 13
|
||||
};
|
||||
|
||||
/* extra bits for each bit length code */
|
||||
static const extra_bits_t extra_blbits[BL_CODES]
|
||||
= { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7 };
|
||||
static const extra_bits_t extra_blbits[BL_CODES] = {
|
||||
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7 };
|
||||
|
||||
#define STORED_BLOCK 0
|
||||
#define STATIC_TREES 1
|
||||
@ -1245,11 +1230,8 @@ static ush *file_type; /* pointer to UNKNOWN, BINARY or ASCII */
|
||||
static int *file_method; /* pointer to DEFLATE or STORE */
|
||||
|
||||
/* ===========================================================================
|
||||
* Local (static) routines in this file.
|
||||
*/
|
||||
|
||||
static void init_block(void);
|
||||
static void pqdownheap(ct_data * tree, int k);
|
||||
static void gen_bitlen(tree_desc * desc);
|
||||
static void gen_codes(ct_data * tree, int max_code);
|
||||
static void build_tree(tree_desc * desc);
|
||||
@ -1263,16 +1245,16 @@ static void set_file_type(void);
|
||||
|
||||
#ifndef DEBUG
|
||||
/* Send a code of the given tree. c and tree must not have side effects */
|
||||
# define send_code(c, tree) send_bits(tree[c].Code, tree[c].Len)
|
||||
#else /* DEBUG */
|
||||
# define send_code(c, tree) \
|
||||
# define SEND_CODE(c, tree) send_bits(tree[c].Code, tree[c].Len)
|
||||
#else
|
||||
# define SEND_CODE(c, tree) \
|
||||
{ \
|
||||
if (verbose > 1) bb_error_msg("\ncd %3d ",(c)); \
|
||||
send_bits(tree[c].Code, tree[c].Len); \
|
||||
}
|
||||
#endif
|
||||
|
||||
#define d_code(dist) \
|
||||
#define D_CODE(dist) \
|
||||
((dist) < 256 ? dist_code[dist] : dist_code[256 + ((dist)>>7)])
|
||||
/* Mapping from a distance to a distance code. dist is the distance - 1 and
|
||||
* must not have side effects. dist_code[256] and dist_code[257] are never
|
||||
@ -1396,22 +1378,6 @@ static void init_block(void)
|
||||
}
|
||||
|
||||
|
||||
/* ===========================================================================
|
||||
* Remove the smallest element from the heap and recreate the heap with
|
||||
* one less element. Updates heap and heap_len.
|
||||
*/
|
||||
|
||||
#define SMALLEST 1
|
||||
/* Index within the heap array of least frequent node in the Huffman tree */
|
||||
|
||||
#define pqremove(tree, top) \
|
||||
{ \
|
||||
top = heap[SMALLEST]; \
|
||||
heap[SMALLEST] = heap[heap_len--]; \
|
||||
pqdownheap(tree, SMALLEST); \
|
||||
}
|
||||
|
||||
|
||||
/* ===========================================================================
|
||||
* Restore the heap property by moving down the tree starting at node k,
|
||||
* exchanging a node with the smallest of its two sons if necessary, stopping
|
||||
@ -1420,9 +1386,8 @@ static void init_block(void)
|
||||
*/
|
||||
|
||||
/* Compares to subtrees, using the tree depth as tie breaker when
|
||||
* the subtrees have equal frequency. This minimizes the worst case length.
|
||||
*/
|
||||
#define smaller(tree, n, m) \
|
||||
* the subtrees have equal frequency. This minimizes the worst case length. */
|
||||
#define SMALLER(tree, n, m) \
|
||||
(tree[n].Freq < tree[m].Freq \
|
||||
|| (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
|
||||
|
||||
@ -1433,11 +1398,11 @@ static void pqdownheap(ct_data * tree, int k)
|
||||
|
||||
while (j <= heap_len) {
|
||||
/* Set j to the smallest of the two sons: */
|
||||
if (j < heap_len && smaller(tree, heap[j + 1], heap[j]))
|
||||
if (j < heap_len && SMALLER(tree, heap[j + 1], heap[j]))
|
||||
j++;
|
||||
|
||||
/* Exit if v is smaller than both sons */
|
||||
if (smaller(tree, v, heap[j]))
|
||||
if (SMALLER(tree, v, heap[j]))
|
||||
break;
|
||||
|
||||
/* Exchange v with the smallest son */
|
||||
@ -1599,6 +1564,20 @@ static void gen_codes(ct_data * tree, int max_code)
|
||||
* and corresponding code. The length opt_len is updated; static_len is
|
||||
* also updated if stree is not null. The field max_code is set.
|
||||
*/
|
||||
|
||||
/* Remove the smallest element from the heap and recreate the heap with
|
||||
* one less element. Updates heap and heap_len. */
|
||||
|
||||
#define SMALLEST 1
|
||||
/* Index within the heap array of least frequent node in the Huffman tree */
|
||||
|
||||
#define PQREMOVE(tree, top) \
|
||||
{ \
|
||||
top = heap[SMALLEST]; \
|
||||
heap[SMALLEST] = heap[heap_len--]; \
|
||||
pqdownheap(tree, SMALLEST); \
|
||||
}
|
||||
|
||||
static void build_tree(tree_desc * desc)
|
||||
{
|
||||
ct_data *tree = desc->dyn_tree;
|
||||
@ -1650,7 +1629,7 @@ static void build_tree(tree_desc * desc)
|
||||
* frequent nodes.
|
||||
*/
|
||||
do {
|
||||
pqremove(tree, n); /* n = node of least frequency */
|
||||
PQREMOVE(tree, n); /* n = node of least frequency */
|
||||
m = heap[SMALLEST]; /* m = node of next least frequency */
|
||||
|
||||
heap[--heap_max] = n; /* keep the nodes sorted by frequency */
|
||||
@ -1761,21 +1740,21 @@ static void send_tree(ct_data * tree, int max_code)
|
||||
continue;
|
||||
} else if (count < min_count) {
|
||||
do {
|
||||
send_code(curlen, bl_tree);
|
||||
SEND_CODE(curlen, bl_tree);
|
||||
} while (--count);
|
||||
} else if (curlen != 0) {
|
||||
if (curlen != prevlen) {
|
||||
send_code(curlen, bl_tree);
|
||||
SEND_CODE(curlen, bl_tree);
|
||||
count--;
|
||||
}
|
||||
Assert(count >= 3 && count <= 6, " 3_6?");
|
||||
send_code(REP_3_6, bl_tree);
|
||||
SEND_CODE(REP_3_6, bl_tree);
|
||||
send_bits(count - 3, 2);
|
||||
} else if (count <= 10) {
|
||||
send_code(REPZ_3_10, bl_tree);
|
||||
SEND_CODE(REPZ_3_10, bl_tree);
|
||||
send_bits(count - 3, 3);
|
||||
} else {
|
||||
send_code(REPZ_11_138, bl_tree);
|
||||
SEND_CODE(REPZ_11_138, bl_tree);
|
||||
send_bits(count - 11, 7);
|
||||
}
|
||||
count = 0;
|
||||
@ -1964,11 +1943,11 @@ static int ct_tally(int dist, int lc)
|
||||
dist--; /* dist = match distance - 1 */
|
||||
Assert((ush) dist < (ush) MAX_DIST
|
||||
&& (ush) lc <= (ush) (MAX_MATCH - MIN_MATCH)
|
||||
&& (ush) d_code(dist) < (ush) D_CODES, "ct_tally: bad match"
|
||||
&& (ush) D_CODE(dist) < (ush) D_CODES, "ct_tally: bad match"
|
||||
);
|
||||
|
||||
dyn_ltree[length_code[lc] + LITERALS + 1].Freq++;
|
||||
dyn_dtree[d_code(dist)].Freq++;
|
||||
dyn_dtree[D_CODE(dist)].Freq++;
|
||||
|
||||
d_buf[last_dist++] = dist;
|
||||
flags |= flag_bit;
|
||||
@ -2025,12 +2004,12 @@ static void compress_block(ct_data * ltree, ct_data * dtree)
|
||||
flag = flag_buf[fx++];
|
||||
lc = l_buf[lx++];
|
||||
if ((flag & 1) == 0) {
|
||||
send_code(lc, ltree); /* send a literal byte */
|
||||
SEND_CODE(lc, ltree); /* send a literal byte */
|
||||
Tracecv(isgraph(lc), (stderr, " '%c' ", lc));
|
||||
} else {
|
||||
/* Here, lc is the match length - MIN_MATCH */
|
||||
code = length_code[lc];
|
||||
send_code(code + LITERALS + 1, ltree); /* send the length code */
|
||||
SEND_CODE(code + LITERALS + 1, ltree); /* send the length code */
|
||||
extra = extra_lbits[code];
|
||||
if (extra != 0) {
|
||||
lc -= base_length[code];
|
||||
@ -2038,10 +2017,10 @@ static void compress_block(ct_data * ltree, ct_data * dtree)
|
||||
}
|
||||
dist = d_buf[dx++];
|
||||
/* Here, dist is the match distance - 1 */
|
||||
code = d_code(dist);
|
||||
code = D_CODE(dist);
|
||||
Assert(code < D_CODES, "bad d_code");
|
||||
|
||||
send_code(code, dtree); /* send the distance code */
|
||||
SEND_CODE(code, dtree); /* send the distance code */
|
||||
extra = extra_dbits[code];
|
||||
if (extra != 0) {
|
||||
dist -= base_dist[code];
|
||||
@ -2052,7 +2031,7 @@ static void compress_block(ct_data * ltree, ct_data * dtree)
|
||||
} while (lx < last_lit);
|
||||
}
|
||||
|
||||
send_code(END_BLOCK, ltree);
|
||||
SEND_CODE(END_BLOCK, ltree);
|
||||
}
|
||||
|
||||
/* ===========================================================================
|
||||
@ -2192,7 +2171,7 @@ int gzip_main(int argc, char **argv)
|
||||
ALLOC(uch, outbuf, OUTBUFSIZ + OUTBUF_EXTRA);
|
||||
ALLOC(ush, d_buf, DIST_BUFSIZE);
|
||||
ALLOC(uch, window, 2L * WSIZE);
|
||||
ALLOC(ush, tab_prefix, 1L << BITS);
|
||||
ALLOC(ush, prev, 1L << BITS);
|
||||
|
||||
/* Initialise the CRC32 table */
|
||||
crc_32_tab = crc32_filltable(0);
|
||||
|
||||
Loading…
Reference in New Issue
Block a user