Index: third_party/zlib/deflate.c |
diff --git a/third_party/zlib/deflate.c b/third_party/zlib/deflate.c |
new file mode 100644 |
index 0000000000000000000000000000000000000000..55ec21570a1a99b54bae2ecaefb9ec4a085080e3 |
--- /dev/null |
+++ b/third_party/zlib/deflate.c |
@@ -0,0 +1,2120 @@ |
+/* deflate.c -- compress data using the deflation algorithm |
+ * Copyright (C) 1995-2010 Jean-loup Gailly and Mark Adler |
+ * For conditions of distribution and use, see copyright notice in zlib.h |
+ */ |
+ |
+/* |
+ * ALGORITHM |
+ * |
+ * The "deflation" process depends on being able to identify portions |
+ * of the input text which are identical to earlier input (within a |
+ * sliding window trailing behind the input currently being processed). |
+ * |
+ * The most straightforward technique turns out to be the fastest for |
+ * most input files: try all possible matches and select the longest. |
+ * The key feature of this algorithm is that insertions into the string |
+ * dictionary are very simple and thus fast, and deletions are avoided |
+ * completely. Insertions are performed at each input character, whereas |
+ * string matches are performed only when the previous match ends. So it |
+ * is preferable to spend more time in matches to allow very fast string |
+ * insertions and avoid deletions. The matching algorithm for small |
+ * strings is inspired from that of Rabin & Karp. A brute force approach |
+ * is used to find longer strings when a small match has been found. |
+ * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze |
+ * (by Leonid Broukhis). |
+ * A previous version of this file used a more sophisticated algorithm |
+ * (by Fiala and Greene) which is guaranteed to run in linear amortized |
+ * time, but has a larger average cost, uses more memory and is patented. |
+ * However the F&G algorithm may be faster for some highly redundant |
+ * files if the parameter max_chain_length (described below) is too large. |
+ * |
+ * ACKNOWLEDGEMENTS |
+ * |
+ * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and |
+ * I found it in 'freeze' written by Leonid Broukhis. |
+ * Thanks to many people for bug reports and testing. |
+ * |
+ * REFERENCES |
+ * |
+ * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification". |
+ * Available in http://www.ietf.org/rfc/rfc1951.txt |
+ * |
+ * A description of the Rabin and Karp algorithm is given in the book |
+ * "Algorithms" by R. Sedgewick, Addison-Wesley, p252. |
+ * |
+ * Fiala,E.R., and Greene,D.H. |
+ * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595 |
+ * |
+ */ |
+ |
+/* @(#) $Id$ */ |
+ |
+#include <assert.h> |
+ |
+#include "deflate.h" |
+#include "x86.h" |
+ |
+const char deflate_copyright[] = |
+ " deflate 1.2.5 Copyright 1995-2010 Jean-loup Gailly and Mark Adler "; |
+/* |
+ If you use the zlib library in a product, an acknowledgment is welcome |
+ in the documentation of your product. If for some reason you cannot |
+ include such an acknowledgment, I would appreciate that you keep this |
+ copyright string in the executable of your product. |
+ */ |
+ |
+/* =========================================================================== |
+ * Function prototypes. |
+ */ |
+typedef enum { |
+ need_more, /* block not completed, need more input or more output */ |
+ block_done, /* block flush performed */ |
+ finish_started, /* finish started, need only more output at next deflate */ |
+ finish_done /* finish done, accept no more input or output */ |
+} block_state; |
+ |
+typedef block_state (*compress_func) OF((deflate_state *s, int flush, |
+ int clas)); |
+/* Compression function. Returns the block state after the call. */ |
+ |
+local void fill_window OF((deflate_state *s)); |
+local block_state deflate_stored OF((deflate_state *s, int flush, int clas)); |
+local block_state deflate_fast OF((deflate_state *s, int flush, int clas)); |
+#ifndef FASTEST |
+local block_state deflate_slow OF((deflate_state *s, int flush, int clas)); |
+#endif |
+local block_state deflate_rle OF((deflate_state *s, int flush)); |
+local block_state deflate_huff OF((deflate_state *s, int flush)); |
+local void lm_init OF((deflate_state *s)); |
+local void putShortMSB OF((deflate_state *s, uInt b)); |
+local void flush_pending OF((z_streamp strm)); |
+ |
+#ifdef ASMV |
+ void match_init OF((void)); /* asm code initialization */ |
+ uInt longest_match OF((deflate_state *s, IPos cur_match, int clas)); |
+#else |
+local uInt longest_match OF((deflate_state *s, IPos cur_match, int clas)); |
+#endif |
+ |
+#ifdef DEBUG |
+local void check_match OF((deflate_state *s, IPos start, IPos match, |
+ int length)); |
+#endif |
+ |
+/* For fill_window_sse.c to use */ |
+ZLIB_INTERNAL int read_buf OF((z_streamp strm, Bytef *buf, unsigned size)); |
+ |
+/* From crc32.c */ |
+extern void ZLIB_INTERNAL crc_reset(deflate_state *const s); |
+extern void ZLIB_INTERNAL crc_finalize(deflate_state *const s); |
+extern void ZLIB_INTERNAL copy_with_crc(z_streamp strm, Bytef *dst, long size); |
+ |
+#ifdef _MSC_VER |
+#define INLINE __inline |
+#else |
+#define INLINE inline |
+#endif |
+ |
+/* Inline optimisation */ |
+local INLINE Pos insert_string_sse(deflate_state *const s, const Pos str); |
+ |
+/* =========================================================================== |
+ * Local data |
+ */ |
+ |
+#define NIL 0 |
+/* Tail of hash chains */ |
+ |
+#ifndef TOO_FAR |
+# define TOO_FAR 4096 |
+#endif |
+/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ |
+ |
+/* Values for max_lazy_match, good_match and max_chain_length, depending on |
+ * the desired pack level (0..9). The values given below have been tuned to |
+ * exclude worst case performance for pathological files. Better values may be |
+ * found for specific files. |
+ */ |
+typedef struct config_s { |
+ ush good_length; /* reduce lazy search above this match length */ |
+ ush max_lazy; /* do not perform lazy search above this match length */ |
+ ush nice_length; /* quit search above this match length */ |
+ ush max_chain; |
+ compress_func func; |
+} config; |
+ |
+#ifdef FASTEST |
+local const config configuration_table[2] = { |
+/* good lazy nice chain */ |
+/* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */ |
+/* 1 */ {4, 4, 8, 4, deflate_fast}}; /* max speed, no lazy matches */ |
+#else |
+local const config configuration_table[10] = { |
+/* good lazy nice chain */ |
+/* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */ |
+/* 1 */ {4, 4, 8, 4, deflate_fast}, /* max speed, no lazy matches */ |
+/* 2 */ {4, 5, 16, 8, deflate_fast}, |
+/* 3 */ {4, 6, 32, 32, deflate_fast}, |
+ |
+/* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */ |
+/* 5 */ {8, 16, 32, 32, deflate_slow}, |
+/* 6 */ {8, 16, 128, 128, deflate_slow}, |
+/* 7 */ {8, 32, 128, 256, deflate_slow}, |
+/* 8 */ {32, 128, 258, 1024, deflate_slow}, |
+/* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* max compression */ |
+#endif |
+ |
+/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 |
+ * For deflate_fast() (levels <= 3) good is ignored and lazy has a different |
+ * meaning. |
+ */ |
+ |
+#define EQUAL 0 |
+/* result of memcmp for equal strings */ |
+ |
+#ifndef NO_DUMMY_DECL |
+struct static_tree_desc_s {int dummy;}; /* for buggy compilers */ |
+#endif |
+ |
+/* =========================================================================== |
+ * Update a hash value with the given input byte |
+ * IN assertion: all calls to to UPDATE_HASH are made with consecutive |
+ * input characters, so that a running hash key can be computed from the |
+ * previous key instead of complete recalculation each time. |
+ */ |
+#define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask) |
+ |
+/* =========================================================================== |
+ * Insert string str in the dictionary and set match_head to the previous head |
+ * of the hash chain (the most recent string with same hash key). Return |
+ * the previous length of the hash chain. |
+ * If this file is compiled with -DFASTEST, the compression level is forced |
+ * to 1, and no hash chains are maintained. |
+ * IN assertion: all calls to to INSERT_STRING are made with consecutive |
+ * input characters and the first MIN_MATCH bytes of str are valid |
+ * (except for the last MIN_MATCH-1 bytes of the input file). |
+ */ |
+local INLINE Pos insert_string_c(deflate_state *const s, const Pos str) |
+{ |
+ Pos ret; |
+ |
+ UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]); |
+#ifdef FASTEST |
+ ret = s->head[s->ins_h]; |
+#else |
+ ret = s->prev[str & s->w_mask] = s->head[s->ins_h]; |
+#endif |
+ s->head[s->ins_h] = str; |
+ |
+ return ret; |
+} |
+ |
+local INLINE Pos insert_string(deflate_state *const s, const Pos str) |
+{ |
+ if (x86_cpu_enable_simd) |
+ return insert_string_sse(s, str); |
+ return insert_string_c(s, str); |
+} |
+ |
+ |
+/* =========================================================================== |
+ * Initialize the hash table (avoiding 64K overflow for 16 bit systems). |
+ * prev[] will be initialized on the fly. |
+ */ |
+#define CLEAR_HASH(s) \ |
+ s->head[s->hash_size-1] = NIL; \ |
+ zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head)); |
+ |
+/* ========================================================================= */ |
+int ZEXPORT deflateInit_(strm, level, version, stream_size) |
+ z_streamp strm; |
+ int level; |
+ const char *version; |
+ int stream_size; |
+{ |
+ return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, |
+ Z_DEFAULT_STRATEGY, version, stream_size); |
+ /* To do: ignore strm->next_in if we use it as window */ |
+} |
+ |
+/* ========================================================================= */ |
+int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy, |
+ version, stream_size) |
+ z_streamp strm; |
+ int level; |
+ int method; |
+ int windowBits; |
+ int memLevel; |
+ int strategy; |
+ const char *version; |
+ int stream_size; |
+{ |
+ unsigned window_padding = 8; |
+ deflate_state *s; |
+ int wrap = 1; |
+ static const char my_version[] = ZLIB_VERSION; |
+ |
+ ushf *overlay; |
+ /* We overlay pending_buf and d_buf+l_buf. This works since the average |
+ * output size for (length,distance) codes is <= 24 bits. |
+ */ |
+ |
+ x86_check_features(); |
+ |
+ if (version == Z_NULL || version[0] != my_version[0] || |
+ stream_size != sizeof(z_stream)) { |
+ return Z_VERSION_ERROR; |
+ } |
+ if (strm == Z_NULL) return Z_STREAM_ERROR; |
+ |
+ strm->msg = Z_NULL; |
+ if (strm->zalloc == (alloc_func)0) { |
+ strm->zalloc = zcalloc; |
+ strm->opaque = (voidpf)0; |
+ } |
+ if (strm->zfree == (free_func)0) strm->zfree = zcfree; |
+ |
+#ifdef FASTEST |
+ if (level != 0) level = 1; |
+#else |
+ if (level == Z_DEFAULT_COMPRESSION) level = 6; |
+#endif |
+ |
+ if (windowBits < 0) { /* suppress zlib wrapper */ |
+ wrap = 0; |
+ windowBits = -windowBits; |
+ } |
+#ifdef GZIP |
+ else if (windowBits > 15) { |
+ wrap = 2; /* write gzip wrapper instead */ |
+ windowBits -= 16; |
+ } |
+#endif |
+ if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED || |
+ windowBits < 8 || windowBits > 15 || level < 0 || level > 9 || |
+ strategy < 0 || strategy > Z_FIXED) { |
+ return Z_STREAM_ERROR; |
+ } |
+ if (windowBits == 8) windowBits = 9; /* until 256-byte window bug fixed */ |
+ s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state)); |
+ if (s == Z_NULL) return Z_MEM_ERROR; |
+ strm->state = (struct internal_state FAR *)s; |
+ s->strm = strm; |
+ |
+ s->wrap = wrap; |
+ s->gzhead = Z_NULL; |
+ s->w_bits = windowBits; |
+ s->w_size = 1 << s->w_bits; |
+ s->w_mask = s->w_size - 1; |
+ |
+ if (x86_cpu_enable_simd) { |
+ s->hash_bits = 15; |
+ } else { |
+ s->hash_bits = memLevel + 7; |
+ } |
+ |
+ s->hash_size = 1 << s->hash_bits; |
+ s->hash_mask = s->hash_size - 1; |
+ s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH); |
+ |
+ s->window = (Bytef *) ZALLOC(strm, s->w_size + window_padding, 2*sizeof(Byte)); |
+ s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos)); |
+ s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos)); |
+ s->class_bitmap = NULL; |
+ zmemzero(&s->cookie_locations, sizeof(s->cookie_locations)); |
+ strm->clas = 0; |
+ |
+ s->high_water = 0; /* nothing written to s->window yet */ |
+ |
+ s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ |
+ |
+ overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2); |
+ s->pending_buf = (uchf *) overlay; |
+ s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L); |
+ |
+ if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || |
+ s->pending_buf == Z_NULL) { |
+ s->status = FINISH_STATE; |
+ strm->msg = (char*)ERR_MSG(Z_MEM_ERROR); |
+ deflateEnd (strm); |
+ return Z_MEM_ERROR; |
+ } |
+ s->d_buf = overlay + s->lit_bufsize/sizeof(ush); |
+ s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize; |
+ |
+ s->level = level; |
+ s->strategy = strategy; |
+ s->method = (Byte)method; |
+ |
+ return deflateReset(strm); |
+} |
+ |
+/* ========================================================================= */ |
+int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength) |
+ z_streamp strm; |
+ const Bytef *dictionary; |
+ uInt dictLength; |
+{ |
+ deflate_state *s; |
+ uInt length = dictLength; |
+ uInt n; |
+ IPos hash_head = 0; |
+ |
+ if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL || |
+ strm->state->wrap == 2 || |
+ (strm->state->wrap == 1 && strm->state->status != INIT_STATE)) |
+ return Z_STREAM_ERROR; |
+ |
+ s = strm->state; |
+ if (s->wrap) |
+ strm->adler = adler32(strm->adler, dictionary, dictLength); |
+ |
+ if (length < MIN_MATCH) return Z_OK; |
+ if (length > s->w_size) { |
+ length = s->w_size; |
+ dictionary += dictLength - length; /* use the tail of the dictionary */ |
+ } |
+ zmemcpy(s->window, dictionary, length); |
+ s->strstart = length; |
+ s->block_start = (long)length; |
+ |
+ /* Insert all strings in the hash table (except for the last two bytes). |
+ * s->lookahead stays null, so s->ins_h will be recomputed at the next |
+ * call of fill_window. |
+ */ |
+ s->ins_h = s->window[0]; |
+ UPDATE_HASH(s, s->ins_h, s->window[1]); |
+ for (n = 0; n <= length - MIN_MATCH; n++) { |
+ insert_string(s, n); |
+ } |
+ if (hash_head) hash_head = 0; /* to make compiler happy */ |
+ return Z_OK; |
+} |
+ |
+/* ========================================================================= */ |
+int ZEXPORT deflateReset (strm) |
+ z_streamp strm; |
+{ |
+ deflate_state *s; |
+ |
+ if (strm == Z_NULL || strm->state == Z_NULL || |
+ strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0) { |
+ return Z_STREAM_ERROR; |
+ } |
+ |
+ strm->total_in = strm->total_out = 0; |
+ strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */ |
+ strm->data_type = Z_UNKNOWN; |
+ |
+ s = (deflate_state *)strm->state; |
+ s->pending = 0; |
+ s->pending_out = s->pending_buf; |
+ TRY_FREE(strm, s->class_bitmap); |
+ s->class_bitmap = NULL; |
+ |
+ if (s->wrap < 0) { |
+ s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */ |
+ } |
+ s->status = s->wrap ? INIT_STATE : BUSY_STATE; |
+ strm->adler = |
+#ifdef GZIP |
+ s->wrap == 2 ? crc32(0L, Z_NULL, 0) : |
+#endif |
+ adler32(0L, Z_NULL, 0); |
+ s->last_flush = Z_NO_FLUSH; |
+ |
+ _tr_init(s); |
+ lm_init(s); |
+ |
+ return Z_OK; |
+} |
+ |
+/* ========================================================================= */ |
+int ZEXPORT deflateSetHeader (strm, head) |
+ z_streamp strm; |
+ gz_headerp head; |
+{ |
+ if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
+ if (strm->state->wrap != 2) return Z_STREAM_ERROR; |
+ strm->state->gzhead = head; |
+ return Z_OK; |
+} |
+ |
+/* ========================================================================= */ |
+int ZEXPORT deflatePrime (strm, bits, value) |
+ z_streamp strm; |
+ int bits; |
+ int value; |
+{ |
+ if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
+ strm->state->bi_valid = bits; |
+ strm->state->bi_buf = (ush)(value & ((1 << bits) - 1)); |
+ return Z_OK; |
+} |
+ |
+/* ========================================================================= */ |
+int ZEXPORT deflateParams(strm, level, strategy) |
+ z_streamp strm; |
+ int level; |
+ int strategy; |
+{ |
+ deflate_state *s; |
+ compress_func func; |
+ int err = Z_OK; |
+ |
+ if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
+ s = strm->state; |
+ |
+#ifdef FASTEST |
+ if (level != 0) level = 1; |
+#else |
+ if (level == Z_DEFAULT_COMPRESSION) level = 6; |
+#endif |
+ if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) { |
+ return Z_STREAM_ERROR; |
+ } |
+ func = configuration_table[s->level].func; |
+ |
+ if ((strategy != s->strategy || func != configuration_table[level].func) && |
+ strm->total_in != 0) { |
+ /* Flush the last buffer: */ |
+ err = deflate(strm, Z_BLOCK); |
+ } |
+ if (s->level != level) { |
+ s->level = level; |
+ s->max_lazy_match = configuration_table[level].max_lazy; |
+ s->good_match = configuration_table[level].good_length; |
+ s->nice_match = configuration_table[level].nice_length; |
+ s->max_chain_length = configuration_table[level].max_chain; |
+ } |
+ s->strategy = strategy; |
+ return err; |
+} |
+ |
+/* ========================================================================= */ |
+int ZEXPORT deflateTune(strm, good_length, max_lazy, nice_length, max_chain) |
+ z_streamp strm; |
+ int good_length; |
+ int max_lazy; |
+ int nice_length; |
+ int max_chain; |
+{ |
+ deflate_state *s; |
+ |
+ if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
+ s = strm->state; |
+ s->good_match = good_length; |
+ s->max_lazy_match = max_lazy; |
+ s->nice_match = nice_length; |
+ s->max_chain_length = max_chain; |
+ return Z_OK; |
+} |
+ |
+/* ========================================================================= |
+ * For the default windowBits of 15 and memLevel of 8, this function returns |
+ * a close to exact, as well as small, upper bound on the compressed size. |
+ * They are coded as constants here for a reason--if the #define's are |
+ * changed, then this function needs to be changed as well. The return |
+ * value for 15 and 8 only works for those exact settings. |
+ * |
+ * For any setting other than those defaults for windowBits and memLevel, |
+ * the value returned is a conservative worst case for the maximum expansion |
+ * resulting from using fixed blocks instead of stored blocks, which deflate |
+ * can emit on compressed data for some combinations of the parameters. |
+ * |
+ * This function could be more sophisticated to provide closer upper bounds for |
+ * every combination of windowBits and memLevel. But even the conservative |
+ * upper bound of about 14% expansion does not seem onerous for output buffer |
+ * allocation. |
+ */ |
+uLong ZEXPORT deflateBound(strm, sourceLen) |
+ z_streamp strm; |
+ uLong sourceLen; |
+{ |
+ deflate_state *s; |
+ uLong complen, wraplen; |
+ Bytef *str; |
+ |
+ /* conservative upper bound for compressed data */ |
+ complen = sourceLen + |
+ ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5; |
+ |
+ /* if can't get parameters, return conservative bound plus zlib wrapper */ |
+ if (strm == Z_NULL || strm->state == Z_NULL) |
+ return complen + 6; |
+ |
+ /* compute wrapper length */ |
+ s = strm->state; |
+ switch (s->wrap) { |
+ case 0: /* raw deflate */ |
+ wraplen = 0; |
+ break; |
+ case 1: /* zlib wrapper */ |
+ wraplen = 6 + (s->strstart ? 4 : 0); |
+ break; |
+ case 2: /* gzip wrapper */ |
+ wraplen = 18; |
+ if (s->gzhead != Z_NULL) { /* user-supplied gzip header */ |
+ if (s->gzhead->extra != Z_NULL) |
+ wraplen += 2 + s->gzhead->extra_len; |
+ str = s->gzhead->name; |
+ if (str != Z_NULL) |
+ do { |
+ wraplen++; |
+ } while (*str++); |
+ str = s->gzhead->comment; |
+ if (str != Z_NULL) |
+ do { |
+ wraplen++; |
+ } while (*str++); |
+ if (s->gzhead->hcrc) |
+ wraplen += 2; |
+ } |
+ break; |
+ default: /* for compiler happiness */ |
+ wraplen = 6; |
+ } |
+ |
+ /* if not default parameters, return conservative bound */ |
+ if (s->w_bits != 15 || s->hash_bits != 8 + 7) |
+ return complen + wraplen; |
+ |
+ /* default settings: return tight bound for that case */ |
+ return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + |
+ (sourceLen >> 25) + 13 - 6 + wraplen; |
+} |
+ |
+/* ========================================================================= |
+ * Put a short in the pending buffer. The 16-bit value is put in MSB order. |
+ * IN assertion: the stream state is correct and there is enough room in |
+ * pending_buf. |
+ */ |
+local void putShortMSB (s, b) |
+ deflate_state *s; |
+ uInt b; |
+{ |
+ put_byte(s, (Byte)(b >> 8)); |
+ put_byte(s, (Byte)(b & 0xff)); |
+} |
+ |
+/* ========================================================================= |
+ * Flush as much pending output as possible. All deflate() output goes |
+ * through this function so some applications may wish to modify it |
+ * to avoid allocating a large strm->next_out buffer and copying into it. |
+ * (See also read_buf()). |
+ */ |
+local void flush_pending(strm) |
+ z_streamp strm; |
+{ |
+ unsigned len = strm->state->pending; |
+ |
+ if (len > strm->avail_out) len = strm->avail_out; |
+ if (len == 0) return; |
+ |
+ zmemcpy(strm->next_out, strm->state->pending_out, len); |
+ strm->next_out += len; |
+ strm->state->pending_out += len; |
+ strm->total_out += len; |
+ strm->avail_out -= len; |
+ strm->state->pending -= len; |
+ if (strm->state->pending == 0) { |
+ strm->state->pending_out = strm->state->pending_buf; |
+ } |
+} |
+ |
+/* ========================================================================= */ |
+int ZEXPORT deflate (strm, flush) |
+ z_streamp strm; |
+ int flush; |
+{ |
+ int old_flush; /* value of flush param for previous deflate call */ |
+ deflate_state *s; |
+ |
+ if (strm == Z_NULL || strm->state == Z_NULL || |
+ flush > Z_BLOCK || flush < 0) { |
+ return Z_STREAM_ERROR; |
+ } |
+ s = strm->state; |
+ |
+ if (strm->next_out == Z_NULL || |
+ (strm->next_in == Z_NULL && strm->avail_in != 0) || |
+ (s->status == FINISH_STATE && flush != Z_FINISH)) { |
+ ERR_RETURN(strm, Z_STREAM_ERROR); |
+ } |
+ if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR); |
+ |
+ s->strm = strm; /* just in case */ |
+ old_flush = s->last_flush; |
+ s->last_flush = flush; |
+ |
+ /* Write the header */ |
+ if (s->status == INIT_STATE) { |
+#ifdef GZIP |
+ if (s->wrap == 2) { |
+ crc_reset(s); |
+ put_byte(s, 31); |
+ put_byte(s, 139); |
+ put_byte(s, 8); |
+ if (s->gzhead == Z_NULL) { |
+ put_byte(s, 0); |
+ put_byte(s, 0); |
+ put_byte(s, 0); |
+ put_byte(s, 0); |
+ put_byte(s, 0); |
+ put_byte(s, s->level == 9 ? 2 : |
+ (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ? |
+ 4 : 0)); |
+ put_byte(s, OS_CODE); |
+ s->status = BUSY_STATE; |
+ } |
+ else { |
+ put_byte(s, (s->gzhead->text ? 1 : 0) + |
+ (s->gzhead->hcrc ? 2 : 0) + |
+ (s->gzhead->extra == Z_NULL ? 0 : 4) + |
+ (s->gzhead->name == Z_NULL ? 0 : 8) + |
+ (s->gzhead->comment == Z_NULL ? 0 : 16) |
+ ); |
+ put_byte(s, (Byte)(s->gzhead->time & 0xff)); |
+ put_byte(s, (Byte)((s->gzhead->time >> 8) & 0xff)); |
+ put_byte(s, (Byte)((s->gzhead->time >> 16) & 0xff)); |
+ put_byte(s, (Byte)((s->gzhead->time >> 24) & 0xff)); |
+ put_byte(s, s->level == 9 ? 2 : |
+ (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ? |
+ 4 : 0)); |
+ put_byte(s, s->gzhead->os & 0xff); |
+ if (s->gzhead->extra != Z_NULL) { |
+ put_byte(s, s->gzhead->extra_len & 0xff); |
+ put_byte(s, (s->gzhead->extra_len >> 8) & 0xff); |
+ } |
+ if (s->gzhead->hcrc) |
+ strm->adler = crc32(strm->adler, s->pending_buf, |
+ s->pending); |
+ s->gzindex = 0; |
+ s->status = EXTRA_STATE; |
+ } |
+ } |
+ else |
+#endif |
+ { |
+ uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8; |
+ uInt level_flags; |
+ |
+ if (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2) |
+ level_flags = 0; |
+ else if (s->level < 6) |
+ level_flags = 1; |
+ else if (s->level == 6) |
+ level_flags = 2; |
+ else |
+ level_flags = 3; |
+ header |= (level_flags << 6); |
+ if (s->strstart != 0) header |= PRESET_DICT; |
+ header += 31 - (header % 31); |
+ |
+ s->status = BUSY_STATE; |
+ putShortMSB(s, header); |
+ |
+ /* Save the adler32 of the preset dictionary: */ |
+ if (s->strstart != 0) { |
+ putShortMSB(s, (uInt)(strm->adler >> 16)); |
+ putShortMSB(s, (uInt)(strm->adler & 0xffff)); |
+ } |
+ strm->adler = adler32(0L, Z_NULL, 0); |
+ } |
+ } |
+#ifdef GZIP |
+ if (s->status == EXTRA_STATE) { |
+ if (s->gzhead->extra != Z_NULL) { |
+ uInt beg = s->pending; /* start of bytes to update crc */ |
+ |
+ while (s->gzindex < (s->gzhead->extra_len & 0xffff)) { |
+ if (s->pending == s->pending_buf_size) { |
+ if (s->gzhead->hcrc && s->pending > beg) |
+ strm->adler = crc32(strm->adler, s->pending_buf + beg, |
+ s->pending - beg); |
+ flush_pending(strm); |
+ beg = s->pending; |
+ if (s->pending == s->pending_buf_size) |
+ break; |
+ } |
+ put_byte(s, s->gzhead->extra[s->gzindex]); |
+ s->gzindex++; |
+ } |
+ if (s->gzhead->hcrc && s->pending > beg) |
+ strm->adler = crc32(strm->adler, s->pending_buf + beg, |
+ s->pending - beg); |
+ if (s->gzindex == s->gzhead->extra_len) { |
+ s->gzindex = 0; |
+ s->status = NAME_STATE; |
+ } |
+ } |
+ else |
+ s->status = NAME_STATE; |
+ } |
+ if (s->status == NAME_STATE) { |
+ if (s->gzhead->name != Z_NULL) { |
+ uInt beg = s->pending; /* start of bytes to update crc */ |
+ int val; |
+ |
+ do { |
+ if (s->pending == s->pending_buf_size) { |
+ if (s->gzhead->hcrc && s->pending > beg) |
+ strm->adler = crc32(strm->adler, s->pending_buf + beg, |
+ s->pending - beg); |
+ flush_pending(strm); |
+ beg = s->pending; |
+ if (s->pending == s->pending_buf_size) { |
+ val = 1; |
+ break; |
+ } |
+ } |
+ val = s->gzhead->name[s->gzindex++]; |
+ put_byte(s, val); |
+ } while (val != 0); |
+ if (s->gzhead->hcrc && s->pending > beg) |
+ strm->adler = crc32(strm->adler, s->pending_buf + beg, |
+ s->pending - beg); |
+ if (val == 0) { |
+ s->gzindex = 0; |
+ s->status = COMMENT_STATE; |
+ } |
+ } |
+ else |
+ s->status = COMMENT_STATE; |
+ } |
+ if (s->status == COMMENT_STATE) { |
+ if (s->gzhead->comment != Z_NULL) { |
+ uInt beg = s->pending; /* start of bytes to update crc */ |
+ int val; |
+ |
+ do { |
+ if (s->pending == s->pending_buf_size) { |
+ if (s->gzhead->hcrc && s->pending > beg) |
+ strm->adler = crc32(strm->adler, s->pending_buf + beg, |
+ s->pending - beg); |
+ flush_pending(strm); |
+ beg = s->pending; |
+ if (s->pending == s->pending_buf_size) { |
+ val = 1; |
+ break; |
+ } |
+ } |
+ val = s->gzhead->comment[s->gzindex++]; |
+ put_byte(s, val); |
+ } while (val != 0); |
+ if (s->gzhead->hcrc && s->pending > beg) |
+ strm->adler = crc32(strm->adler, s->pending_buf + beg, |
+ s->pending - beg); |
+ if (val == 0) |
+ s->status = HCRC_STATE; |
+ } |
+ else |
+ s->status = HCRC_STATE; |
+ } |
+ if (s->status == HCRC_STATE) { |
+ if (s->gzhead->hcrc) { |
+ if (s->pending + 2 > s->pending_buf_size) |
+ flush_pending(strm); |
+ if (s->pending + 2 <= s->pending_buf_size) { |
+ put_byte(s, (Byte)(strm->adler & 0xff)); |
+ put_byte(s, (Byte)((strm->adler >> 8) & 0xff)); |
+ strm->adler = crc32(0L, Z_NULL, 0); |
+ s->status = BUSY_STATE; |
+ } |
+ } |
+ else |
+ s->status = BUSY_STATE; |
+ } |
+#endif |
+ |
+ /* Flush as much pending output as possible */ |
+ if (s->pending != 0) { |
+ flush_pending(strm); |
+ if (strm->avail_out == 0) { |
+ /* Since avail_out is 0, deflate will be called again with |
+ * more output space, but possibly with both pending and |
+ * avail_in equal to zero. There won't be anything to do, |
+ * but this is not an error situation so make sure we |
+ * return OK instead of BUF_ERROR at next call of deflate: |
+ */ |
+ s->last_flush = -1; |
+ return Z_OK; |
+ } |
+ |
+ /* Make sure there is something to do and avoid duplicate consecutive |
+ * flushes. For repeated and useless calls with Z_FINISH, we keep |
+ * returning Z_STREAM_END instead of Z_BUF_ERROR. |
+ */ |
+ } else if (strm->avail_in == 0 && flush <= old_flush && |
+ flush != Z_FINISH) { |
+ ERR_RETURN(strm, Z_BUF_ERROR); |
+ } |
+ |
+ /* User must not provide more input after the first FINISH: */ |
+ if (s->status == FINISH_STATE && strm->avail_in != 0) { |
+ ERR_RETURN(strm, Z_BUF_ERROR); |
+ } |
+ |
+ /* Start a new block or continue the current one. |
+ */ |
+ if (strm->avail_in != 0 || s->lookahead != 0 || |
+ (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) { |
+ block_state bstate; |
+ |
+ if (strm->clas && s->class_bitmap == NULL) { |
+ /* This is the first time that we have seen alternative class |
+ * data. All data up till this point has been standard class. */ |
+ s->class_bitmap = (Bytef*) ZALLOC(strm, s->w_size/4, sizeof(Byte)); |
+ zmemzero(s->class_bitmap, s->w_size/4); |
+ } |
+ |
+ if (strm->clas && s->strategy == Z_RLE) { |
+ /* We haven't patched deflate_rle. */ |
+ ERR_RETURN(strm, Z_BUF_ERROR); |
+ } |
+ |
+ if (s->strategy == Z_HUFFMAN_ONLY) { |
+ bstate = deflate_huff(s, flush); |
+ } else if (s->strategy == Z_RLE) { |
+ bstate = deflate_rle(s, flush); |
+ } else { |
+ bstate = (*(configuration_table[s->level].func)) |
+ (s, flush, strm->clas); |
+ } |
+ |
+ if (bstate == finish_started || bstate == finish_done) { |
+ s->status = FINISH_STATE; |
+ } |
+ if (bstate == need_more || bstate == finish_started) { |
+ if (strm->avail_out == 0) { |
+ s->last_flush = -1; /* avoid BUF_ERROR next call, see above */ |
+ } |
+ return Z_OK; |
+ /* If flush != Z_NO_FLUSH && avail_out == 0, the next call |
+ * of deflate should use the same flush parameter to make sure |
+ * that the flush is complete. So we don't have to output an |
+ * empty block here, this will be done at next call. This also |
+ * ensures that for a very small output buffer, we emit at most |
+ * one empty block. |
+ */ |
+ } |
+ if (bstate == block_done) { |
+ if (flush == Z_PARTIAL_FLUSH) { |
+ _tr_align(s); |
+ } else if (flush != Z_BLOCK) { /* FULL_FLUSH or SYNC_FLUSH */ |
+ _tr_stored_block(s, (char*)0, 0L, 0); |
+ /* For a full flush, this empty block will be recognized |
+ * as a special marker by inflate_sync(). |
+ */ |
+ if (flush == Z_FULL_FLUSH) { |
+ CLEAR_HASH(s); /* forget history */ |
+ if (s->lookahead == 0) { |
+ s->strstart = 0; |
+ s->block_start = 0L; |
+ } |
+ } |
+ } |
+ flush_pending(strm); |
+ if (strm->avail_out == 0) { |
+ s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */ |
+ return Z_OK; |
+ } |
+ } |
+ } |
+ Assert(strm->avail_out > 0, "bug2"); |
+ |
+ if (flush != Z_FINISH) return Z_OK; |
+ if (s->wrap <= 0) return Z_STREAM_END; |
+ |
+ /* Write the trailer */ |
+#ifdef GZIP |
+ if (s->wrap == 2) { |
+ crc_finalize(s); |
+ put_byte(s, (Byte)(strm->adler & 0xff)); |
+ put_byte(s, (Byte)((strm->adler >> 8) & 0xff)); |
+ put_byte(s, (Byte)((strm->adler >> 16) & 0xff)); |
+ put_byte(s, (Byte)((strm->adler >> 24) & 0xff)); |
+ put_byte(s, (Byte)(strm->total_in & 0xff)); |
+ put_byte(s, (Byte)((strm->total_in >> 8) & 0xff)); |
+ put_byte(s, (Byte)((strm->total_in >> 16) & 0xff)); |
+ put_byte(s, (Byte)((strm->total_in >> 24) & 0xff)); |
+ } |
+ else |
+#endif |
+ { |
+ putShortMSB(s, (uInt)(strm->adler >> 16)); |
+ putShortMSB(s, (uInt)(strm->adler & 0xffff)); |
+ } |
+ flush_pending(strm); |
+ /* If avail_out is zero, the application will call deflate again |
+ * to flush the rest. |
+ */ |
+ if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */ |
+ return s->pending != 0 ? Z_OK : Z_STREAM_END; |
+} |
+ |
+/* ========================================================================= */ |
+int ZEXPORT deflateEnd (strm) |
+ z_streamp strm; |
+{ |
+ int status; |
+ |
+ if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
+ |
+ status = strm->state->status; |
+ if (status != INIT_STATE && |
+ status != EXTRA_STATE && |
+ status != NAME_STATE && |
+ status != COMMENT_STATE && |
+ status != HCRC_STATE && |
+ status != BUSY_STATE && |
+ status != FINISH_STATE) { |
+ return Z_STREAM_ERROR; |
+ } |
+ |
+ /* Deallocate in reverse order of allocations: */ |
+ TRY_FREE(strm, strm->state->pending_buf); |
+ TRY_FREE(strm, strm->state->head); |
+ TRY_FREE(strm, strm->state->prev); |
+ TRY_FREE(strm, strm->state->window); |
+ TRY_FREE(strm, strm->state->class_bitmap); |
+ |
+ ZFREE(strm, strm->state); |
+ strm->state = Z_NULL; |
+ |
+ return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK; |
+} |
+ |
+/* ========================================================================= |
+ * Copy the source state to the destination state. |
+ * To simplify the source, this is not supported for 16-bit MSDOS (which |
+ * doesn't have enough memory anyway to duplicate compression states). |
+ */ |
+int ZEXPORT deflateCopy (dest, source) |
+ z_streamp dest; |
+ z_streamp source; |
+{ |
+#ifdef MAXSEG_64K |
+ return Z_STREAM_ERROR; |
+#else |
+ deflate_state *ds; |
+ deflate_state *ss; |
+ ushf *overlay; |
+ |
+ |
+ if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) { |
+ return Z_STREAM_ERROR; |
+ } |
+ |
+ ss = source->state; |
+ |
+ zmemcpy(dest, source, sizeof(z_stream)); |
+ |
+ ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state)); |
+ if (ds == Z_NULL) return Z_MEM_ERROR; |
+ dest->state = (struct internal_state FAR *) ds; |
+ zmemcpy(ds, ss, sizeof(deflate_state)); |
+ ds->strm = dest; |
+ |
+ ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte)); |
+ ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos)); |
+ ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos)); |
+ overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2); |
+ ds->pending_buf = (uchf *) overlay; |
+ |
+ if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL || |
+ ds->pending_buf == Z_NULL) { |
+ deflateEnd (dest); |
+ return Z_MEM_ERROR; |
+ } |
+ /* following zmemcpy do not work for 16-bit MSDOS */ |
+ zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte)); |
+ zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos)); |
+ zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos)); |
+ zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size); |
+ |
+ ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf); |
+ ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush); |
+ ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize; |
+ |
+ ds->l_desc.dyn_tree = ds->dyn_ltree; |
+ ds->d_desc.dyn_tree = ds->dyn_dtree; |
+ ds->bl_desc.dyn_tree = ds->bl_tree; |
+ |
+ return Z_OK; |
+#endif /* MAXSEG_64K */ |
+} |
+ |
+/* =========================================================================== |
+ * Read a new buffer from the current input stream, update the adler32 |
+ * and total number of bytes read. All deflate() input goes through |
+ * this function so some applications may wish to modify it to avoid |
+ * allocating a large strm->next_in buffer and copying from it. |
+ * (See also flush_pending()). |
+ */ |
+ZLIB_INTERNAL int read_buf(strm, buf, size) |
+ z_streamp strm; |
+ Bytef *buf; |
+ unsigned size; |
+{ |
+ unsigned len = strm->avail_in; |
+ |
+ if (len > size) len = size; |
+ if (len == 0) return 0; |
+ |
+ strm->avail_in -= len; |
+ |
+#ifdef GZIP |
+ if (strm->state->wrap == 2) { |
+ copy_with_crc(strm, buf, len); |
+ } |
+ else |
+#endif |
+ { |
+ zmemcpy(buf, strm->next_in, len); |
+ if (strm->state->wrap == 1) |
+ strm->adler = adler32(strm->adler, buf, len); |
+ } |
+ strm->next_in += len; |
+ strm->total_in += len; |
+ |
+ return (int)len; |
+} |
+ |
+/* =========================================================================== |
+ * Initialize the "longest match" routines for a new zlib stream |
+ */ |
+local void lm_init (s) |
+ deflate_state *s; |
+{ |
+ s->window_size = (ulg)2L*s->w_size; |
+ |
+ CLEAR_HASH(s); |
+ |
+ /* Set the default configuration parameters: |
+ */ |
+ s->max_lazy_match = configuration_table[s->level].max_lazy; |
+ s->good_match = configuration_table[s->level].good_length; |
+ s->nice_match = configuration_table[s->level].nice_length; |
+ s->max_chain_length = configuration_table[s->level].max_chain; |
+ |
+ s->strstart = 0; |
+ s->block_start = 0L; |
+ s->lookahead = 0; |
+ s->match_length = s->prev_length = MIN_MATCH-1; |
+ s->match_available = 0; |
+ s->ins_h = 0; |
+#ifndef FASTEST |
+#ifdef ASMV |
+ match_init(); /* initialize the asm code */ |
+#endif |
+#endif |
+} |
+ |
+/* class_set sets bits [offset,offset+len) in s->class_bitmap to either 1 (if |
+ * class != 0) or 0 (otherwise). */ |
+local void class_set(s, offset, len, clas) |
+ deflate_state *s; |
+ IPos offset; |
+ uInt len; |
+ int clas; |
+{ |
+ IPos byte = offset >> 3; |
+ IPos bit = offset & 7; |
+ Bytef class_byte_value = clas ? 0xff : 0x00; |
+ Bytef class_bit_value = clas ? 1 : 0; |
+ static const Bytef mask[8] = {0xfe, 0xfd, 0xfb, 0xf7, |
+ 0xef, 0xdf, 0xbf, 0x7f}; |
+ |
+ if (bit) { |
+ while (len) { |
+ s->class_bitmap[byte] &= mask[bit]; |
+ s->class_bitmap[byte] |= class_bit_value << bit; |
+ bit++; |
+ len--; |
+ if (bit == 8) { |
+ bit = 0; |
+ byte++; |
+ break; |
+ } |
+ } |
+ } |
+ |
+ while (len >= 8) { |
+ s->class_bitmap[byte++] = class_byte_value; |
+ len -= 8; |
+ } |
+ |
+ while (len) { |
+ s->class_bitmap[byte] &= mask[bit]; |
+ s->class_bitmap[byte] |= class_bit_value << bit; |
+ bit++; |
+ len--; |
+ } |
+} |
+ |
+local int class_at(s, window_offset) |
+ deflate_state *s; |
+ IPos window_offset; |
+{ |
+ IPos byte = window_offset >> 3; |
+ IPos bit = window_offset & 7; |
+ return (s->class_bitmap[byte] >> bit) & 1; |
+} |
+ |
+#ifndef FASTEST |
+/* =========================================================================== |
+ * Set match_start to the longest match starting at the given string and |
+ * return its length. Matches shorter or equal to prev_length are discarded, |
+ * in which case the result is equal to prev_length and match_start is |
+ * garbage. |
+ * IN assertions: cur_match is the head of the hash chain for the current |
+ * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 |
+ * OUT assertion: the match length is not greater than s->lookahead. |
+ */ |
+#ifndef ASMV |
+/* For 80x86 and 680x0, an optimized version will be provided in match.asm or |
+ * match.S. The code will be functionally equivalent. |
+ */ |
+local uInt longest_match(s, cur_match, clas) |
+ deflate_state *s; |
+ IPos cur_match; /* current match */ |
+ int clas; |
+{ |
+ unsigned chain_length = s->max_chain_length;/* max hash chain length */ |
+ register Bytef *scan = s->window + s->strstart; /* current string */ |
+ register Bytef *match; /* matched string */ |
+ register int len; /* length of current match */ |
+ int best_len = s->prev_length; /* best match length so far */ |
+ int nice_match = s->nice_match; /* stop if match long enough */ |
+ IPos limit = s->strstart > (IPos)MAX_DIST(s) ? |
+ s->strstart - (IPos)MAX_DIST(s) : NIL; |
+ /* Stop when cur_match becomes <= limit. To simplify the code, |
+ * we prevent matches with the string of window index 0. |
+ */ |
+ Posf *prev = s->prev; |
+ uInt wmask = s->w_mask; |
+ |
+#ifdef UNALIGNED_OK |
+ /* Compare two bytes at a time. Note: this is not always beneficial. |
+ * Try with and without -DUNALIGNED_OK to check. |
+ */ |
+ register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1; |
+ register ush scan_start = *(ushf*)scan; |
+ register ush scan_end = *(ushf*)(scan+best_len-1); |
+#else |
+ register Bytef *strend = s->window + s->strstart + MAX_MATCH; |
+ register Byte scan_end1 = scan[best_len-1]; |
+ register Byte scan_end = scan[best_len]; |
+#endif |
+ |
+ /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. |
+ * It is easy to get rid of this optimization if necessary. |
+ */ |
+ Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); |
+ |
+ /* Do not waste too much time if we already have a good match: */ |
+ if (s->prev_length >= s->good_match) { |
+ chain_length >>= 2; |
+ } |
+ /* Do not look for matches beyond the end of the input. This is necessary |
+ * to make deflate deterministic. |
+ */ |
+ if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead; |
+ |
+ Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); |
+ |
+ do { |
+ Assert(cur_match < s->strstart, "no future"); |
+ match = s->window + cur_match; |
+ /* If the matched data is in the wrong class, skip it. */ |
+ if (s->class_bitmap && class_at(s, cur_match) != clas) |
+ continue; |
+ |
+ /* Skip to next match if the match length cannot increase |
+ * or if the match length is less than 2. Note that the checks below |
+ * for insufficient lookahead only occur occasionally for performance |
+ * reasons. Therefore uninitialized memory will be accessed, and |
+ * conditional jumps will be made that depend on those values. |
+ * However the length of the match is limited to the lookahead, so |
+ * the output of deflate is not affected by the uninitialized values. |
+ */ |
+#if (defined(UNALIGNED_OK) && MAX_MATCH == 258) |
+ /* This code assumes sizeof(unsigned short) == 2. Do not use |
+ * UNALIGNED_OK if your compiler uses a different size. |
+ */ |
+ if (*(ushf*)(match+best_len-1) != scan_end || |
+ *(ushf*)match != scan_start) continue; |
+ |
+ /* It is not necessary to compare scan[2] and match[2] since they are |
+ * always equal when the other bytes match, given that the hash keys |
+ * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at |
+ * strstart+3, +5, ... up to strstart+257. We check for insufficient |
+ * lookahead only every 4th comparison; the 128th check will be made |
+ * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is |
+ * necessary to put more guard bytes at the end of the window, or |
+ * to check more often for insufficient lookahead. |
+ */ |
+ Assert(scan[2] == match[2], "scan[2]?"); |
+ scan++, match++; |
+ do { |
+ } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) && |
+ *(ushf*)(scan+=2) == *(ushf*)(match+=2) && |
+ *(ushf*)(scan+=2) == *(ushf*)(match+=2) && |
+ *(ushf*)(scan+=2) == *(ushf*)(match+=2) && |
+ scan < strend); |
+ /* The funny "do {}" generates better code on most compilers */ |
+ |
+ /* Here, scan <= window+strstart+257 */ |
+ Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); |
+ if (*scan == *match) scan++; |
+ |
+ len = (MAX_MATCH - 1) - (int)(strend-scan); |
+ scan = strend - (MAX_MATCH-1); |
+ |
+#error "UNALIGNED_OK hasn't been patched." |
+ |
+#else /* UNALIGNED_OK */ |
+ |
+ if (match[best_len] != scan_end || |
+ match[best_len-1] != scan_end1 || |
+ *match != *scan || |
+ *++match != scan[1]) continue; |
+ |
+ /* The check at best_len-1 can be removed because it will be made |
+ * again later. (This heuristic is not always a win.) |
+ * It is not necessary to compare scan[2] and match[2] since they |
+ * are always equal when the other bytes match, given that |
+ * the hash keys are equal and that HASH_BITS >= 8. |
+ */ |
+ scan += 2, match++; |
+ Assert(*scan == *match, "match[2]?"); |
+ |
+ if (!s->class_bitmap) { |
+ /* We check for insufficient lookahead only every 8th comparison; |
+ * the 256th check will be made at strstart+258. |
+ */ |
+ do { |
+ } while (*++scan == *++match && *++scan == *++match && |
+ *++scan == *++match && *++scan == *++match && |
+ *++scan == *++match && *++scan == *++match && |
+ *++scan == *++match && *++scan == *++match && |
+ scan < strend); |
+ } else { |
+ /* We have to be mindful of the class of the data and not stray. */ |
+ do { |
+ } while (*++scan == *++match && |
+ class_at(s, match - s->window) == clas && |
+ scan < strend); |
+ } |
+ |
+ Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); |
+ |
+ len = MAX_MATCH - (int)(strend - scan); |
+ scan = strend - MAX_MATCH; |
+ |
+#endif /* UNALIGNED_OK */ |
+ |
+ if (len > best_len) { |
+ s->match_start = cur_match; |
+ best_len = len; |
+ if (len >= nice_match) break; |
+#ifdef UNALIGNED_OK |
+ scan_end = *(ushf*)(scan+best_len-1); |
+#else |
+ scan_end1 = scan[best_len-1]; |
+ scan_end = scan[best_len]; |
+#endif |
+ } |
+ } while ((cur_match = prev[cur_match & wmask]) > limit |
+ && --chain_length != 0); |
+ |
+ if ((uInt)best_len <= s->lookahead) return (uInt)best_len; |
+ return s->lookahead; |
+} |
+#endif /* ASMV */ |
+ |
+/* cookie_match is a replacement for longest_match in the case of cookie data. |
+ * Here we only wish to match the entire value so trying the partial matches in |
+ * longest_match is both wasteful and often fails to find the correct match. |
+ * |
+ * So we take the djb2 hash of the cookie and look up the last position for a |
+ * match in a special hash table. */ |
+local uInt cookie_match(s, start, len) |
+ deflate_state *s; |
+ IPos start; |
+ unsigned len; |
+{ |
+ unsigned hash = 5381; |
+ Bytef *str = s->window + start; |
+ unsigned i; |
+ IPos cookie_location; |
+ |
+ if (len >= MAX_MATCH || len == 0) |
+ return 0; |
+ |
+ for (i = 0; i < len; i++) |
+ hash = ((hash << 5) + hash) + str[i]; |
+ |
+ hash &= Z_COOKIE_HASH_MASK; |
+ cookie_location = s->cookie_locations[hash]; |
+ s->cookie_locations[hash] = start; |
+ s->match_start = 0; |
+ if (cookie_location && |
+ (start - cookie_location) > len && |
+ (start - cookie_location) < MAX_DIST(s) && |
+ len <= s->lookahead) { |
+ for (i = 0; i < len; i++) { |
+ if (s->window[start+i] != s->window[cookie_location+i] || |
+ class_at(s, cookie_location+i) != 1) { |
+ return 0; |
+ } |
+ } |
+ /* Check that we aren't matching a prefix of another cookie by ensuring |
+ * that the final byte is either a semicolon (which cannot appear in a |
+ * cookie value), or the match is followed by non-cookie data. */ |
+ if (s->window[cookie_location+len-1] != ';' && |
+ class_at(s, cookie_location+len) != 0) { |
+ return 0; |
+ } |
+ s->match_start = cookie_location; |
+ return len; |
+ } |
+ |
+ return 0; |
+} |
+ |
+ |
+#else /* FASTEST */ |
+ |
+/* --------------------------------------------------------------------------- |
+ * Optimized version for FASTEST only |
+ */ |
+local uInt longest_match(s, cur_match, clas) |
+ deflate_state *s; |
+ IPos cur_match; /* current match */ |
+ int clas; |
+{ |
+ register Bytef *scan = s->window + s->strstart; /* current string */ |
+ register Bytef *match; /* matched string */ |
+ register int len; /* length of current match */ |
+ register Bytef *strend = s->window + s->strstart + MAX_MATCH; |
+ |
+#error "This code not patched" |
+ |
+ /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. |
+ * It is easy to get rid of this optimization if necessary. |
+ */ |
+ Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); |
+ |
+ Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); |
+ |
+ Assert(cur_match < s->strstart, "no future"); |
+ |
+ match = s->window + cur_match; |
+ |
+ /* Return failure if the match length is less than 2: |
+ */ |
+ if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1; |
+ |
+ /* The check at best_len-1 can be removed because it will be made |
+ * again later. (This heuristic is not always a win.) |
+ * It is not necessary to compare scan[2] and match[2] since they |
+ * are always equal when the other bytes match, given that |
+ * the hash keys are equal and that HASH_BITS >= 8. |
+ */ |
+ scan += 2, match += 2; |
+ Assert(*scan == *match, "match[2]?"); |
+ |
+ /* We check for insufficient lookahead only every 8th comparison; |
+ * the 256th check will be made at strstart+258. |
+ */ |
+ do { |
+ } while (*++scan == *++match && *++scan == *++match && |
+ *++scan == *++match && *++scan == *++match && |
+ *++scan == *++match && *++scan == *++match && |
+ *++scan == *++match && *++scan == *++match && |
+ scan < strend); |
+ |
+ Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); |
+ |
+ len = MAX_MATCH - (int)(strend - scan); |
+ |
+ if (len < MIN_MATCH) return MIN_MATCH - 1; |
+ |
+ s->match_start = cur_match; |
+ return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead; |
+} |
+ |
+#endif /* FASTEST */ |
+ |
+#ifdef DEBUG |
+/* =========================================================================== |
+ * Check that the match at match_start is indeed a match. |
+ */ |
+local void check_match(s, start, match, length) |
+ deflate_state *s; |
+ IPos start, match; |
+ int length; |
+{ |
+ /* check that the match is indeed a match */ |
+ if (zmemcmp(s->window + match, |
+ s->window + start, length) != EQUAL) { |
+ fprintf(stderr, " start %u, match %u, length %d\n", |
+ start, match, length); |
+ do { |
+ fprintf(stderr, "%c%c", s->window[match++], s->window[start++]); |
+ } while (--length != 0); |
+ z_error("invalid match"); |
+ } |
+ if (z_verbose > 1) { |
+ fprintf(stderr,"\\[%d,%d]", start-match, length); |
+ do { putc(s->window[start++], stderr); } while (--length != 0); |
+ } |
+} |
+#else |
+# define check_match(s, start, match, length) |
+#endif /* DEBUG */ |
+ |
+/* =========================================================================== |
+ * Fill the window when the lookahead becomes insufficient. |
+ * Updates strstart and lookahead. |
+ * |
+ * IN assertion: lookahead < MIN_LOOKAHEAD |
+ * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD |
+ * At least one byte has been read, or avail_in == 0; reads are |
+ * performed for at least two bytes (required for the zip translate_eol |
+ * option -- not supported here). |
+ */ |
+local void fill_window_c(deflate_state *s); |
+ |
+local void fill_window(deflate_state *s) |
+{ |
+ if (x86_cpu_enable_simd) { |
+ fill_window_sse(s); |
+ return; |
+ } |
+ |
+ fill_window_c(s); |
+} |
+ |
+local void fill_window_c(s) |
+ deflate_state *s; |
+{ |
+ register unsigned n, m; |
+ register Posf *p; |
+ unsigned more; /* Amount of free space at the end of the window. */ |
+ uInt wsize = s->w_size; |
+ |
+ do { |
+ more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart); |
+ |
+ /* Deal with !@#$% 64K limit: */ |
+ if (sizeof(int) <= 2) { |
+ if (more == 0 && s->strstart == 0 && s->lookahead == 0) { |
+ more = wsize; |
+ |
+ } else if (more == (unsigned)(-1)) { |
+ /* Very unlikely, but possible on 16 bit machine if |
+ * strstart == 0 && lookahead == 1 (input done a byte at time) |
+ */ |
+ more--; |
+ } |
+ } |
+ |
+ /* If the window is almost full and there is insufficient lookahead, |
+ * move the upper half to the lower one to make room in the upper half. |
+ */ |
+ if (s->strstart >= wsize+MAX_DIST(s)) { |
+ |
+ zmemcpy(s->window, s->window+wsize, (unsigned)wsize); |
+ s->match_start -= wsize; |
+ s->strstart -= wsize; /* we now have strstart >= MAX_DIST */ |
+ s->block_start -= (long) wsize; |
+ |
+ /* Slide the hash table (could be avoided with 32 bit values |
+ at the expense of memory usage). We slide even when level == 0 |
+ to keep the hash table consistent if we switch back to level > 0 |
+ later. (Using level 0 permanently is not an optimal usage of |
+ zlib, so we don't care about this pathological case.) |
+ */ |
+ n = s->hash_size; |
+ p = &s->head[n]; |
+ do { |
+ m = *--p; |
+ *p = (Pos)(m >= wsize ? m-wsize : NIL); |
+ } while (--n); |
+ |
+ n = wsize; |
+#ifndef FASTEST |
+ p = &s->prev[n]; |
+ do { |
+ m = *--p; |
+ *p = (Pos)(m >= wsize ? m-wsize : NIL); |
+ /* If n is not on any hash chain, prev[n] is garbage but |
+ * its value will never be used. |
+ */ |
+ } while (--n); |
+#endif |
+ |
+ for (n = 0; n < Z_COOKIE_HASH_SIZE; n++) { |
+ if (s->cookie_locations[n] > wsize) { |
+ s->cookie_locations[n] -= wsize; |
+ } else { |
+ s->cookie_locations[n] = 0; |
+ } |
+ } |
+ |
+ if (s->class_bitmap) { |
+ zmemcpy(s->class_bitmap, s->class_bitmap + s->w_size/8, |
+ s->w_size/8); |
+ zmemzero(s->class_bitmap + s->w_size/8, s->w_size/8); |
+ } |
+ |
+ more += wsize; |
+ } |
+ if (s->strm->avail_in == 0) return; |
+ |
+ /* If there was no sliding: |
+ * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 && |
+ * more == window_size - lookahead - strstart |
+ * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1) |
+ * => more >= window_size - 2*WSIZE + 2 |
+ * In the BIG_MEM or MMAP case (not yet supported), |
+ * window_size == input_size + MIN_LOOKAHEAD && |
+ * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD. |
+ * Otherwise, window_size == 2*WSIZE so more >= 2. |
+ * If there was sliding, more >= WSIZE. So in all cases, more >= 2. |
+ */ |
+ Assert(more >= 2, "more < 2"); |
+ |
+ n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more); |
+ if (s->class_bitmap != NULL) { |
+ class_set(s, s->strstart + s->lookahead, n, s->strm->clas); |
+ } |
+ s->lookahead += n; |
+ |
+ /* Initialize the hash value now that we have some input: */ |
+ if (s->lookahead >= MIN_MATCH) { |
+ s->ins_h = s->window[s->strstart]; |
+ UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); |
+#if MIN_MATCH != 3 |
+ Call UPDATE_HASH() MIN_MATCH-3 more times |
+#endif |
+ } |
+ /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage, |
+ * but this is not important since only literal bytes will be emitted. |
+ */ |
+ |
+ } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0); |
+ |
+ /* If the WIN_INIT bytes after the end of the current data have never been |
+ * written, then zero those bytes in order to avoid memory check reports of |
+ * the use of uninitialized (or uninitialised as Julian writes) bytes by |
+ * the longest match routines. Update the high water mark for the next |
+ * time through here. WIN_INIT is set to MAX_MATCH since the longest match |
+ * routines allow scanning to strstart + MAX_MATCH, ignoring lookahead. |
+ */ |
+ if (s->high_water < s->window_size) { |
+ ulg curr = s->strstart + (ulg)(s->lookahead); |
+ ulg init; |
+ |
+ if (s->high_water < curr) { |
+ /* Previous high water mark below current data -- zero WIN_INIT |
+ * bytes or up to end of window, whichever is less. |
+ */ |
+ init = s->window_size - curr; |
+ if (init > WIN_INIT) |
+ init = WIN_INIT; |
+ zmemzero(s->window + curr, (unsigned)init); |
+ s->high_water = curr + init; |
+ } |
+ else if (s->high_water < (ulg)curr + WIN_INIT) { |
+ /* High water mark at or above current data, but below current data |
+ * plus WIN_INIT -- zero out to current data plus WIN_INIT, or up |
+ * to end of window, whichever is less. |
+ */ |
+ init = (ulg)curr + WIN_INIT - s->high_water; |
+ if (init > s->window_size - s->high_water) |
+ init = s->window_size - s->high_water; |
+ zmemzero(s->window + s->high_water, (unsigned)init); |
+ s->high_water += init; |
+ } |
+ } |
+} |
+ |
+/* =========================================================================== |
+ * Flush the current block, with given end-of-file flag. |
+ * IN assertion: strstart is set to the end of the current match. |
+ */ |
+#define FLUSH_BLOCK_ONLY(s, last) { \ |
+ _tr_flush_block(s, (s->block_start >= 0L ? \ |
+ (charf *)&s->window[(unsigned)s->block_start] : \ |
+ (charf *)Z_NULL), \ |
+ (ulg)((long)s->strstart - s->block_start), \ |
+ (last)); \ |
+ s->block_start = s->strstart; \ |
+ flush_pending(s->strm); \ |
+ Tracev((stderr,"[FLUSH]")); \ |
+} |
+ |
+/* Same but force premature exit if necessary. */ |
+#define FLUSH_BLOCK(s, last) { \ |
+ FLUSH_BLOCK_ONLY(s, last); \ |
+ if (s->strm->avail_out == 0) return (last) ? finish_started : need_more; \ |
+} |
+ |
+/* =========================================================================== |
+ * Copy without compression as much as possible from the input stream, return |
+ * the current block state. |
+ * This function does not insert new strings in the dictionary since |
+ * uncompressible data is probably not useful. This function is used |
+ * only for the level=0 compression option. |
+ * NOTE: this function should be optimized to avoid extra copying from |
+ * window to pending_buf. |
+ */ |
+local block_state deflate_stored(s, flush, clas) |
+ deflate_state *s; |
+ int flush; |
+ int clas; |
+{ |
+ /* Stored blocks are limited to 0xffff bytes, pending_buf is limited |
+ * to pending_buf_size, and each stored block has a 5 byte header: |
+ */ |
+ ulg max_block_size = 0xffff; |
+ ulg max_start; |
+ |
+ if (max_block_size > s->pending_buf_size - 5) { |
+ max_block_size = s->pending_buf_size - 5; |
+ } |
+ |
+ /* Copy as much as possible from input to output: */ |
+ for (;;) { |
+ /* Fill the window as much as possible: */ |
+ if (s->lookahead <= 1) { |
+ |
+ Assert(s->strstart < s->w_size+MAX_DIST(s) || |
+ s->block_start >= (long)s->w_size, "slide too late"); |
+ |
+ fill_window(s); |
+ if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more; |
+ |
+ if (s->lookahead == 0) break; /* flush the current block */ |
+ } |
+ Assert(s->block_start >= 0L, "block gone"); |
+ |
+ s->strstart += s->lookahead; |
+ s->lookahead = 0; |
+ |
+ /* Emit a stored block if pending_buf will be full: */ |
+ max_start = s->block_start + max_block_size; |
+ if (s->strstart == 0 || (ulg)s->strstart >= max_start) { |
+ /* strstart == 0 is possible when wraparound on 16-bit machine */ |
+ s->lookahead = (uInt)(s->strstart - max_start); |
+ s->strstart = (uInt)max_start; |
+ FLUSH_BLOCK(s, 0); |
+ } |
+ /* Flush if we may have to slide, otherwise block_start may become |
+ * negative and the data will be gone: |
+ */ |
+ if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) { |
+ FLUSH_BLOCK(s, 0); |
+ } |
+ } |
+ FLUSH_BLOCK(s, flush == Z_FINISH); |
+ return flush == Z_FINISH ? finish_done : block_done; |
+} |
+ |
+/* =========================================================================== |
+ * Compress as much as possible from the input stream, return the current |
+ * block state. |
+ * This function does not perform lazy evaluation of matches and inserts |
+ * new strings in the dictionary only for unmatched strings or for short |
+ * matches. It is used only for the fast compression options. |
+ */ |
+local block_state deflate_fast(s, flush, clas) |
+ deflate_state *s; |
+ int flush; |
+ int clas; |
+{ |
+ IPos hash_head; /* head of the hash chain */ |
+ int bflush; /* set if current block must be flushed */ |
+ |
+ if (clas != 0) { |
+ /* We haven't patched this code for alternative class data. */ |
+ return Z_BUF_ERROR; |
+ } |
+ |
+ for (;;) { |
+ /* Make sure that we always have enough lookahead, except |
+ * at the end of the input file. We need MAX_MATCH bytes |
+ * for the next match, plus MIN_MATCH bytes to insert the |
+ * string following the next match. |
+ */ |
+ if (s->lookahead < MIN_LOOKAHEAD) { |
+ fill_window(s); |
+ if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { |
+ return need_more; |
+ } |
+ if (s->lookahead == 0) break; /* flush the current block */ |
+ } |
+ |
+ /* Insert the string window[strstart .. strstart+2] in the |
+ * dictionary, and set hash_head to the head of the hash chain: |
+ */ |
+ hash_head = NIL; |
+ if (s->lookahead >= MIN_MATCH) { |
+ hash_head = insert_string(s, s->strstart); |
+ } |
+ |
+ /* Find the longest match, discarding those <= prev_length. |
+ * At this point we have always match_length < MIN_MATCH |
+ */ |
+ if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) { |
+ /* To simplify the code, we prevent matches with the string |
+ * of window index 0 (in particular we have to avoid a match |
+ * of the string with itself at the start of the input file). |
+ */ |
+ s->match_length = longest_match (s, hash_head, clas); |
+ /* longest_match() sets match_start */ |
+ } |
+ if (s->match_length >= MIN_MATCH) { |
+ check_match(s, s->strstart, s->match_start, s->match_length); |
+ |
+ _tr_tally_dist(s, s->strstart - s->match_start, |
+ s->match_length - MIN_MATCH, bflush); |
+ |
+ s->lookahead -= s->match_length; |
+ |
+ /* Insert new strings in the hash table only if the match length |
+ * is not too large. This saves time but degrades compression. |
+ */ |
+#ifndef FASTEST |
+ if (s->match_length <= s->max_insert_length && |
+ s->lookahead >= MIN_MATCH) { |
+ s->match_length--; /* string at strstart already in table */ |
+ do { |
+ s->strstart++; |
+ hash_head = insert_string(s, s->strstart); |
+ /* strstart never exceeds WSIZE-MAX_MATCH, so there are |
+ * always MIN_MATCH bytes ahead. |
+ */ |
+ } while (--s->match_length != 0); |
+ s->strstart++; |
+ } else |
+#endif |
+ { |
+ s->strstart += s->match_length; |
+ s->match_length = 0; |
+ s->ins_h = s->window[s->strstart]; |
+ UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); |
+#if MIN_MATCH != 3 |
+ Call UPDATE_HASH() MIN_MATCH-3 more times |
+#endif |
+ /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not |
+ * matter since it will be recomputed at next deflate call. |
+ */ |
+ } |
+ } else { |
+ /* No match, output a literal byte */ |
+ Tracevv((stderr,"%c", s->window[s->strstart])); |
+ _tr_tally_lit (s, s->window[s->strstart], bflush); |
+ s->lookahead--; |
+ s->strstart++; |
+ } |
+ if (bflush) FLUSH_BLOCK(s, 0); |
+ } |
+ FLUSH_BLOCK(s, flush == Z_FINISH); |
+ return flush == Z_FINISH ? finish_done : block_done; |
+} |
+ |
+#ifndef FASTEST |
+/* =========================================================================== |
+ * Same as above, but achieves better compression. We use a lazy |
+ * evaluation for matches: a match is finally adopted only if there is |
+ * no better match at the next window position. |
+ */ |
+local block_state deflate_slow(s, flush, clas) |
+ deflate_state *s; |
+ int flush; |
+ int clas; |
+{ |
+ IPos hash_head; /* head of hash chain */ |
+ int bflush; /* set if current block must be flushed */ |
+ uInt input_length ; |
+ int first = 1; /* first says whether this is the first iteration |
+ of the loop, below. */ |
+ |
+ if (clas == Z_CLASS_COOKIE) { |
+ if (s->lookahead) { |
+ /* Alternative class data must always be presented at the beginning |
+ * of a block. */ |
+ return Z_BUF_ERROR; |
+ } |
+ input_length = s->strm->avail_in; |
+ } |
+ |
+ /* Process the input block. */ |
+ for (;;) { |
+ /* Make sure that we always have enough lookahead, except |
+ * at the end of the input file. We need MAX_MATCH bytes |
+ * for the next match, plus MIN_MATCH bytes to insert the |
+ * string following the next match. |
+ */ |
+ if (s->lookahead < MIN_LOOKAHEAD) { |
+ fill_window(s); |
+ if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { |
+ return need_more; |
+ } |
+ if (s->lookahead == 0) break; /* flush the current block */ |
+ } |
+ |
+ /* Insert the string window[strstart .. strstart+2] in the |
+ * dictionary, and set hash_head to the head of the hash chain: |
+ */ |
+ hash_head = NIL; |
+ if (s->lookahead >= MIN_MATCH) { |
+ hash_head = insert_string(s, s->strstart); |
+ } |
+ |
+ /* Find the longest match, discarding those <= prev_length. |
+ */ |
+ s->prev_length = s->match_length, s->prev_match = s->match_start; |
+ s->match_length = MIN_MATCH-1; |
+ |
+ if (clas == Z_CLASS_COOKIE && first) { |
+ s->match_length = cookie_match(s, s->strstart, input_length); |
+ } else if (clas == Z_CLASS_STANDARD && |
+ hash_head != NIL && |
+ s->prev_length < s->max_lazy_match && |
+ s->strstart - hash_head <= MAX_DIST(s)) { |
+ /* To simplify the code, we prevent matches with the string |
+ * of window index 0 (in particular we have to avoid a match |
+ * of the string with itself at the start of the input file). |
+ */ |
+ s->match_length = longest_match (s, hash_head, clas); |
+ |
+ /* longest_match() sets match_start */ |
+ |
+ if (s->match_length <= 5 && (s->strategy == Z_FILTERED |
+#if TOO_FAR <= 32767 |
+ || (s->match_length == MIN_MATCH && |
+ s->strstart - s->match_start > TOO_FAR) |
+#endif |
+ )) { |
+ |
+ /* If prev_match is also MIN_MATCH, match_start is garbage |
+ * but we will ignore the current match anyway. |
+ */ |
+ s->match_length = MIN_MATCH-1; |
+ } |
+ } |
+ /* If there was a match at the previous step and the current |
+ * match is not better, output the previous match: |
+ */ |
+ first = 0; |
+ if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length && |
+ /* We will only accept an exact match for Z_CLASS_COOKIE data and |
+ * we won't match Z_CLASS_HUFFMAN_ONLY data at all. */ |
+ (clas == Z_CLASS_STANDARD || (clas == Z_CLASS_COOKIE && |
+ s->prev_length == input_length && |
+ s->prev_match > 0 && |
+ /* We require that a Z_CLASS_COOKIE match be |
+ * preceded by either a semicolon (which cannot be |
+ * part of a cookie), or non-cookie data. This is |
+ * to prevent a cookie from being a suffix of |
+ * another. */ |
+ (class_at(s, s->prev_match-1) == Z_CLASS_STANDARD || |
+ *(s->window + s->prev_match-1) == ';')))) { |
+ uInt max_insert = s->strstart + s->lookahead - MIN_MATCH; |
+ /* Do not insert strings in hash table beyond this. */ |
+ |
+ check_match(s, s->strstart-1, s->prev_match, s->prev_length); |
+ |
+ _tr_tally_dist(s, s->strstart -1 - s->prev_match, |
+ s->prev_length - MIN_MATCH, bflush); |
+ |
+ /* Insert in hash table all strings up to the end of the match. |
+ * strstart-1 and strstart are already inserted. If there is not |
+ * enough lookahead, the last two strings are not inserted in |
+ * the hash table. |
+ */ |
+ s->lookahead -= s->prev_length-1; |
+ s->prev_length -= 2; |
+ do { |
+ if (++s->strstart <= max_insert) { |
+ hash_head = insert_string(s, s->strstart); |
+ } |
+ } while (--s->prev_length != 0); |
+ s->match_available = 0; |
+ s->match_length = MIN_MATCH-1; |
+ s->strstart++; |
+ |
+ if (bflush) FLUSH_BLOCK(s, 0); |
+ |
+ } else if (s->match_available) { |
+ /* If there was no match at the previous position, output a |
+ * single literal. If there was a match but the current match |
+ * is longer, truncate the previous match to a single literal. |
+ */ |
+ Tracevv((stderr,"%c", s->window[s->strstart-1])); |
+ _tr_tally_lit(s, s->window[s->strstart-1], bflush); |
+ if (bflush) { |
+ FLUSH_BLOCK_ONLY(s, 0); |
+ } |
+ s->strstart++; |
+ s->lookahead--; |
+ if (s->strm->avail_out == 0) return need_more; |
+ } else { |
+ /* There is no previous match to compare with, wait for |
+ * the next step to decide. |
+ */ |
+ s->match_available = 1; |
+ s->strstart++; |
+ s->lookahead--; |
+ } |
+ } |
+ Assert (flush != Z_NO_FLUSH, "no flush?"); |
+ if (s->match_available) { |
+ Tracevv((stderr,"%c", s->window[s->strstart-1])); |
+ _tr_tally_lit(s, s->window[s->strstart-1], bflush); |
+ s->match_available = 0; |
+ } |
+ FLUSH_BLOCK(s, flush == Z_FINISH); |
+ return flush == Z_FINISH ? finish_done : block_done; |
+} |
+#endif /* FASTEST */ |
+ |
+/* =========================================================================== |
+ * For Z_RLE, simply look for runs of bytes, generate matches only of distance |
+ * one. Do not maintain a hash table. (It will be regenerated if this run of |
+ * deflate switches away from Z_RLE.) |
+ */ |
+local block_state deflate_rle(s, flush) |
+ deflate_state *s; |
+ int flush; |
+{ |
+ int bflush; /* set if current block must be flushed */ |
+ uInt prev; /* byte at distance one to match */ |
+ Bytef *scan, *strend; /* scan goes up to strend for length of run */ |
+ |
+ for (;;) { |
+ /* Make sure that we always have enough lookahead, except |
+ * at the end of the input file. We need MAX_MATCH bytes |
+ * for the longest encodable run. |
+ */ |
+ if (s->lookahead < MAX_MATCH) { |
+ fill_window(s); |
+ if (s->lookahead < MAX_MATCH && flush == Z_NO_FLUSH) { |
+ return need_more; |
+ } |
+ if (s->lookahead == 0) break; /* flush the current block */ |
+ } |
+ |
+ /* See how many times the previous byte repeats */ |
+ s->match_length = 0; |
+ if (s->lookahead >= MIN_MATCH && s->strstart > 0) { |
+ scan = s->window + s->strstart - 1; |
+ prev = *scan; |
+ if (prev == *++scan && prev == *++scan && prev == *++scan) { |
+ strend = s->window + s->strstart + MAX_MATCH; |
+ do { |
+ } while (prev == *++scan && prev == *++scan && |
+ prev == *++scan && prev == *++scan && |
+ prev == *++scan && prev == *++scan && |
+ prev == *++scan && prev == *++scan && |
+ scan < strend); |
+ s->match_length = MAX_MATCH - (int)(strend - scan); |
+ if (s->match_length > s->lookahead) |
+ s->match_length = s->lookahead; |
+ } |
+ } |
+ |
+ /* Emit match if have run of MIN_MATCH or longer, else emit literal */ |
+ if (s->match_length >= MIN_MATCH) { |
+ check_match(s, s->strstart, s->strstart - 1, s->match_length); |
+ |
+ _tr_tally_dist(s, 1, s->match_length - MIN_MATCH, bflush); |
+ |
+ s->lookahead -= s->match_length; |
+ s->strstart += s->match_length; |
+ s->match_length = 0; |
+ } else { |
+ /* No match, output a literal byte */ |
+ Tracevv((stderr,"%c", s->window[s->strstart])); |
+ _tr_tally_lit (s, s->window[s->strstart], bflush); |
+ s->lookahead--; |
+ s->strstart++; |
+ } |
+ if (bflush) FLUSH_BLOCK(s, 0); |
+ } |
+ FLUSH_BLOCK(s, flush == Z_FINISH); |
+ return flush == Z_FINISH ? finish_done : block_done; |
+} |
+ |
+/* =========================================================================== |
+ * For Z_HUFFMAN_ONLY, do not look for matches. Do not maintain a hash table. |
+ * (It will be regenerated if this run of deflate switches away from Huffman.) |
+ */ |
+local block_state deflate_huff(s, flush) |
+ deflate_state *s; |
+ int flush; |
+{ |
+ int bflush; /* set if current block must be flushed */ |
+ |
+ for (;;) { |
+ /* Make sure that we have a literal to write. */ |
+ if (s->lookahead == 0) { |
+ fill_window(s); |
+ if (s->lookahead == 0) { |
+ if (flush == Z_NO_FLUSH) |
+ return need_more; |
+ break; /* flush the current block */ |
+ } |
+ } |
+ |
+ /* Output a literal byte */ |
+ s->match_length = 0; |
+ Tracevv((stderr,"%c", s->window[s->strstart])); |
+ _tr_tally_lit (s, s->window[s->strstart], bflush); |
+ s->lookahead--; |
+ s->strstart++; |
+ if (bflush) FLUSH_BLOCK(s, 0); |
+ } |
+ FLUSH_BLOCK(s, flush == Z_FINISH); |
+ return flush == Z_FINISH ? finish_done : block_done; |
+} |
+ |
+/* Safe to inline this as GCC/clang will use inline asm and Visual Studio will |
+ * use intrinsic without extra params |
+ */ |
+local INLINE Pos insert_string_sse(deflate_state *const s, const Pos str) |
+{ |
+ Pos ret; |
+ unsigned *ip, val, h = 0; |
+ |
+ ip = (unsigned *)&s->window[str]; |
+ val = *ip; |
+ |
+ if (s->level >= 6) |
+ val &= 0xFFFFFF; |
+ |
+/* Windows clang should use inline asm */ |
+#if defined(_MSC_VER) && !defined(__clang__) |
+ h = _mm_crc32_u32(h, val); |
+#elif defined(__i386__) || defined(__amd64__) |
+ __asm__ __volatile__ ( |
+ "crc32 %1,%0\n\t" |
+ : "+r" (h) |
+ : "r" (val) |
+ ); |
+#else |
+ /* This should never happen */ |
+ assert(0); |
+#endif |
+ |
+ ret = s->head[h & s->hash_mask]; |
+ s->head[h & s->hash_mask] = str; |
+ s->prev[str & s->w_mask] = ret; |
+ return ret; |
+} |