diff options
Diffstat (limited to 'zlib/trees.c')
| -rw-r--r-- | zlib/trees.c | 157 |
1 files changed, 68 insertions, 89 deletions
diff --git a/zlib/trees.c b/zlib/trees.c index 52c820fa2..a818c8819 100644 --- a/zlib/trees.c +++ b/zlib/trees.c @@ -58,15 +58,19 @@ #define REPZ_11_138 18 /* repeat a zero length 11-138 times (7 bits of repeat count) */ +/*@unchecked@*/ /*@observer@*/ local const int extra_lbits[LENGTH_CODES] /* extra bits for each length code */ = {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}; +/*@unchecked@*/ /*@observer@*/ local const int extra_dbits[D_CODES] /* extra bits for each distance code */ = {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}; +/*@unchecked@*/ /*@observer@*/ local const int extra_blbits[BL_CODES]/* extra bits for each bit length code */ = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7}; +/*@unchecked@*/ /*@observer@*/ local const uch bl_order[BL_CODES] = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15}; /* The lengths of the bit length codes are sent in order of decreasing @@ -119,19 +123,24 @@ local int base_dist[D_CODES]; #endif /* GEN_TREES_H */ struct static_tree_desc_s { +/*@observer@*/ /*@null@*/ const ct_data *static_tree; /* static tree or NULL */ +/*@observer@*/ /*@null@*/ const intf *extra_bits; /* extra bits for each code or NULL */ int extra_base; /* base index for extra_bits */ int elems; /* max number of elements in the tree */ int max_length; /* max bit length for the codes */ }; +/*@unchecked@*/ /*@observer@*/ local static_tree_desc static_l_desc = {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS}; +/*@unchecked@*/ /*@observer@*/ local static_tree_desc static_d_desc = {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS}; +/*@unchecked@*/ /*@observer@*/ local static_tree_desc static_bl_desc = {(const ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS}; @@ -139,28 +148,45 @@ local static_tree_desc static_bl_desc = * Local (static) routines in this file. */ -local void tr_static_init OF((void)); -local void init_block OF((deflate_state *s)); -local void pqdownheap OF((deflate_state *s, ct_data *tree, int k)); -local void gen_bitlen OF((deflate_state *s, tree_desc *desc)); -local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count)); -local void build_tree OF((deflate_state *s, tree_desc *desc)); -local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code)); -local void send_tree OF((deflate_state *s, ct_data *tree, int max_code)); -local int build_bl_tree OF((deflate_state *s)); +local void tr_static_init OF((void)) + /*@*/; +local void init_block OF((deflate_state *s)) + /*@modifies s @*/; +local void pqdownheap OF((deflate_state *s, ct_data *tree, int k)) + /*@modifies s @*/; +local void gen_bitlen OF((deflate_state *s, tree_desc *desc)) + /*@modifies s, desc @*/; +local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count)) + /*@modifies tree @*/; +local void build_tree OF((deflate_state *s, tree_desc *desc)) + /*@modifies s, desc @*/; +local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code)) + /*@modifies s, tree @*/; +local void send_tree OF((deflate_state *s, ct_data *tree, int max_code)) + /*@modifies s @*/; +local int build_bl_tree OF((deflate_state *s)) + /*@modifies s @*/; local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes, - int blcodes)); + int blcodes)) + /*@modifies s @*/; local void compress_block OF((deflate_state *s, ct_data *ltree, - ct_data *dtree)); -local void set_data_type OF((deflate_state *s)); -local unsigned bi_reverse OF((unsigned value, int length)); -local void bi_windup OF((deflate_state *s)); -local void bi_flush OF((deflate_state *s)); + ct_data *dtree)) + /*@modifies s @*/; +local void set_data_type OF((deflate_state *s)) + /*@modifies s @*/; +local unsigned bi_reverse OF((unsigned value, int length)) + /*@*/; +local void bi_windup OF((deflate_state *s)) + /*@modifies s @*/; +local void bi_flush OF((deflate_state *s)) + /*@modifies s @*/; local void copy_block OF((deflate_state *s, charf *buf, unsigned len, - int header)); + int header)) + /*@modifies s @*/; #ifdef GEN_TREES_H -local void gen_trees_header OF((void)); +local void gen_trees_header OF((void)) + /*@*/; #endif #ifndef DEBUG @@ -187,12 +213,10 @@ local void gen_trees_header OF((void)); * IN assertion: length <= 16 and value fits in length bits. */ #ifdef DEBUG -local void send_bits OF((deflate_state *s, int value, int length)); +local void send_bits OF((deflate_state *s, int value, int length)) + /*@*/; -local void send_bits(s, value, length) - deflate_state *s; - int value; /* value to send */ - int length; /* number of bits */ +local void send_bits(deflate_state *s, int value, int length) { Tracevv((stderr," l %2d v %4x ", length, value)); Assert(length > 0 && length <= 15, "invalid length"); @@ -235,7 +259,7 @@ local void send_bits(s, value, length) /* =========================================================================== * Initialize the various 'constant' tables. */ -local void tr_static_init() +local void tr_static_init(void) { #if defined(GEN_TREES_H) || !defined(STDC) static int static_init_done = 0; @@ -327,7 +351,7 @@ local void tr_static_init() ((i) == (last)? "\n};\n\n" : \ ((i) % (width) == (width)-1 ? ",\n" : ", ")) -void gen_trees_header() +void gen_trees_header(void) { FILE *header = fopen("trees.h", "w"); int i; @@ -379,8 +403,7 @@ void gen_trees_header() /* =========================================================================== * Initialize the tree data structures for a new zlib stream. */ -void _tr_init(s) - deflate_state *s; +void _tr_init(deflate_state *s) { tr_static_init(); @@ -408,8 +431,7 @@ void _tr_init(s) /* =========================================================================== * Initialize a new block. */ -local void init_block(s) - deflate_state *s; +local void init_block(deflate_state *s) { int n; /* iterates over tree elements */ @@ -452,10 +474,7 @@ local void init_block(s) * when the heap property is re-established (each father smaller than its * two sons). */ -local void pqdownheap(s, tree, k) - deflate_state *s; - ct_data *tree; /* the tree to restore */ - int k; /* node to move down */ +local void pqdownheap(deflate_state *s, ct_data *tree, int k) { int v = s->heap[k]; int j = k << 1; /* left son of k */ @@ -487,9 +506,7 @@ local void pqdownheap(s, tree, k) * The length opt_len is updated; static_len is also updated if stree is * not null. */ -local void gen_bitlen(s, desc) - deflate_state *s; - tree_desc *desc; /* the tree descriptor */ +local void gen_bitlen(deflate_state *s, tree_desc *desc) { ct_data *tree = desc->dyn_tree; int max_code = desc->max_code; @@ -574,10 +591,7 @@ local void gen_bitlen(s, desc) * OUT assertion: the field code is set for all tree elements of non * zero code length. */ -local void gen_codes (tree, max_code, bl_count) - ct_data *tree; /* the tree to decorate */ - int max_code; /* largest code with non zero frequency */ - ushf *bl_count; /* number of codes at each bit length */ +local void gen_codes (ct_data *tree, int max_code, ushf *bl_count) { ush next_code[MAX_BITS+1]; /* next code value for each bit length */ ush code = 0; /* running code value */ @@ -616,9 +630,7 @@ local void gen_codes (tree, max_code, bl_count) * 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. */ -local void build_tree(s, desc) - deflate_state *s; - tree_desc *desc; /* the tree descriptor */ +local void build_tree(deflate_state *s, tree_desc *desc) { ct_data *tree = desc->dyn_tree; const ct_data *stree = desc->stat_desc->static_tree; @@ -704,10 +716,7 @@ local void build_tree(s, desc) * Scan a literal or distance tree to determine the frequencies of the codes * in the bit length tree. */ -local void scan_tree (s, tree, max_code) - deflate_state *s; - ct_data *tree; /* the tree to be scanned */ - int max_code; /* and its largest code of non zero frequency */ +local void scan_tree (deflate_state *s, ct_data *tree, int max_code) { int n; /* iterates over all tree elements */ int prevlen = -1; /* last emitted length */ @@ -749,10 +758,7 @@ local void scan_tree (s, tree, max_code) * Send a literal or distance tree in compressed form, using the codes in * bl_tree. */ -local void send_tree (s, tree, max_code) - deflate_state *s; - ct_data *tree; /* the tree to be scanned */ - int max_code; /* and its largest code of non zero frequency */ +local void send_tree (deflate_state *s, ct_data *tree, int max_code) { int n; /* iterates over all tree elements */ int prevlen = -1; /* last emitted length */ @@ -800,8 +806,7 @@ local void send_tree (s, tree, max_code) * Construct the Huffman tree for the bit lengths and return the index in * bl_order of the last bit length code to send. */ -local int build_bl_tree(s) - deflate_state *s; +local int build_bl_tree(deflate_state *s) { int max_blindex; /* index of last bit length code of non zero freq */ @@ -835,9 +840,7 @@ local int build_bl_tree(s) * lengths of the bit length codes, the literal tree and the distance tree. * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. */ -local void send_all_trees(s, lcodes, dcodes, blcodes) - deflate_state *s; - int lcodes, dcodes, blcodes; /* number of codes for each tree */ +local void send_all_trees(deflate_state *s, int lcodes, int dcodes, int blcodes) { int rank; /* index in bl_order */ @@ -864,11 +867,7 @@ local void send_all_trees(s, lcodes, dcodes, blcodes) /* =========================================================================== * Send a stored block */ -void _tr_stored_block(s, buf, stored_len, eof) - deflate_state *s; - charf *buf; /* input block */ - ulg stored_len; /* length of input block */ - int eof; /* true if this is the last block for a file */ +void _tr_stored_block(deflate_state *s, charf *buf, ulg stored_len, int eof) { send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */ #ifdef DEBUG @@ -889,8 +888,7 @@ void _tr_stored_block(s, buf, stored_len, eof) * To simplify the code, we assume the worst case of last real code encoded * on one bit only. */ -void _tr_align(s) - deflate_state *s; +void _tr_align(deflate_state *s) { send_bits(s, STATIC_TREES<<1, 3); send_code(s, END_BLOCK, static_ltree); @@ -918,11 +916,7 @@ void _tr_align(s) * Determine the best encoding for the current block: dynamic trees, static * trees or store, and output the encoded block to the zip file. */ -void _tr_flush_block(s, buf, stored_len, eof) - deflate_state *s; - charf *buf; /* input block, or NULL if too old */ - ulg stored_len; /* length of input block */ - int eof; /* true if this is the last block for a file */ +void _tr_flush_block(deflate_state *s, charf *buf, ulg stored_len, int eof) { ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ int max_blindex = 0; /* index of last bit length code of non zero freq */ @@ -1018,10 +1012,7 @@ void _tr_flush_block(s, buf, stored_len, eof) * Save the match info and tally the frequency counts. Return true if * the current block must be flushed. */ -int _tr_tally (s, dist, lc) - deflate_state *s; - unsigned dist; /* distance of matched string */ - unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */ +int _tr_tally (deflate_state *s, unsigned dist, unsigned lc) { s->d_buf[s->last_lit] = (ush)dist; s->l_buf[s->last_lit++] = (uch)lc; @@ -1068,10 +1059,7 @@ int _tr_tally (s, dist, lc) /* =========================================================================== * Send the block data compressed using the given Huffman trees */ -local void compress_block(s, ltree, dtree) - deflate_state *s; - ct_data *ltree; /* literal tree */ - ct_data *dtree; /* distance tree */ +local void compress_block(deflate_state *s, ct_data *ltree, ct_data *dtree) { unsigned dist; /* distance of matched string */ int lc; /* match length or unmatched char (if dist == 0) */ @@ -1122,8 +1110,7 @@ local void compress_block(s, ltree, dtree) * IN assertion: the fields freq of dyn_ltree are set and the total of all * frequencies does not exceed 64K (to fit in an int on 16 bit machines). */ -local void set_data_type(s) - deflate_state *s; +local void set_data_type(deflate_state *s) { int n = 0; unsigned ascii_freq = 0; @@ -1139,9 +1126,7 @@ local void set_data_type(s) * method would use a table) * IN assertion: 1 <= len <= 15 */ -local unsigned bi_reverse(code, len) - unsigned code; /* the value to invert */ - int len; /* its bit length */ +local unsigned bi_reverse(unsigned code, int len) { register unsigned res = 0; do { @@ -1154,8 +1139,7 @@ local unsigned bi_reverse(code, len) /* =========================================================================== * Flush the bit buffer, keeping at most 7 bits in it. */ -local void bi_flush(s) - deflate_state *s; +local void bi_flush(deflate_state *s) { if (s->bi_valid == 16) { put_short(s, s->bi_buf); @@ -1171,8 +1155,7 @@ local void bi_flush(s) /* =========================================================================== * Flush the bit buffer and align the output on a byte boundary */ -local void bi_windup(s) - deflate_state *s; +local void bi_windup(deflate_state *s) { if (s->bi_valid > 8) { put_short(s, s->bi_buf); @@ -1190,11 +1173,7 @@ local void bi_windup(s) * Copy a stored block, storing first the length and its * one's complement if requested. */ -local void copy_block(s, buf, len, header) - deflate_state *s; - charf *buf; /* the input data */ - unsigned len; /* its length */ - int header; /* true if block header must be written */ +local void copy_block(deflate_state *s, charf *buf, unsigned len, int header) { bi_windup(s); /* align on byte boundary */ s->last_eob_len = 8; /* enough lookahead for inflate */ |