1 #ifndef TREES_H_
2 #define TREES_H_
3 
4 /* Constants */
5 
6 #define DIST_CODE_LEN  512
7 /* see definition of array dist_code in trees.c */
8 
9 #define MAX_BL_BITS 7
10 /* Bit length codes must not exceed MAX_BL_BITS bits */
11 
12 #define REP_3_6      16
13 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
14 
15 #define REPZ_3_10    17
16 /* repeat a zero length 3-10 times  (3 bits of repeat count) */
17 
18 #define REPZ_11_138  18
19 /* repeat a zero length 11-138 times  (7 bits of repeat count) */
20 
21 static const int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
22     = {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};
23 
24 static const int extra_dbits[D_CODES] /* extra bits for each distance code */
25     = {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};
26 
27 static const int extra_blbits[BL_CODES] /* extra bits for each bit length code */
28     = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
29 
30 static const unsigned char bl_order[BL_CODES]
31     = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
32  /* The lengths of the bit length codes are sent in order of decreasing
33   * probability, to avoid transmitting the lengths for unused bit length codes.
34   */
35 
36 
37 /* Function definitions */
38 void gen_codes        (ct_data *tree, int max_code, uint16_t *bl_count);
39 
40 #endif
41