# endif
#endif
+//remove??
#define INBUF_EXTRA 64 /* required by unlzw() */
#ifndef OUTBUFSIZ
# define OUTBUFSIZ 16384 /* output buffer size */
# endif
#endif
+//remove??
#define OUTBUF_EXTRA 2048 /* required by unlzw() */
#ifndef DIST_BUFSIZE
/* 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)
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
/* ===========================================================================
- * Prototypes for local functions.
*/
static void fill_window(void);
#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 */
{
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;
+ }
}
* 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.
*
* (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.
* 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
* 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.
- *
*/
/* ===========================================================================
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
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);
#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
}
-/* ===========================================================================
- * 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
*/
/* 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]))
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 */
* 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;
* 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 */
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;
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;
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];
}
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];
} while (lx < last_lit);
}
- send_code(END_BLOCK, ltree);
+ SEND_CODE(END_BLOCK, ltree);
}
/* ===========================================================================
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);
projects / oweals / busybox.git / commitdiff