lzx_compress.c: fix min value of LENGTH_CODEWORD_LIMIT

[wimlib] / src / lzx_compress.c

diff --git a/src/lzx_compress.c b/src/lzx_compress.c
index 47d8bf0be9714e7fe1a9a1f846d6f1cf9f92cff7..b6d603d620a84ecba60e9d900f8908d2d7812a19 100644 (file)
--- a/src/lzx_compress.c
+++ b/src/lzx_compress.c
@@ -410,8 +410,10 @@ struct lzx_compressor {
 
        /* The matches and literals that the parser has chosen for the current
         * block.  The required length of this array is limited by the maximum
-        * number of matches that can ever be chosen for a single block.  */
-       struct lzx_sequence chosen_sequences[DIV_ROUND_UP(LZX_DIV_BLOCK_SIZE, LZX_MIN_MATCH_LEN)];
+        * number of matches that can ever be chosen for a single block, plus
+        * one for the special entry at the end.  */
+       struct lzx_sequence chosen_sequences[
+                      DIV_ROUND_UP(LZX_DIV_BLOCK_SIZE, LZX_MIN_MATCH_LEN) + 1];
 
        /* Tables for mapping adjusted offsets to offset slots  */
 
@@ -548,7 +550,7 @@ struct lzx_output_bitstream {
 
 /* Can the specified number of bits always be added to 'bitbuf' after any
  * pending 16-bit coding units have been flushed?  */
-#define CAN_BUFFER(n)  ((n) <= (8 * sizeof(machine_word_t)) - 16)
+#define CAN_BUFFER(n)  ((n) <= (8 * sizeof(machine_word_t)) - 15)
 
 /*
  * Initialize the output bitstream.
@@ -634,7 +636,7 @@ lzx_make_huffman_codes(struct lzx_compressor *c)
 
        STATIC_ASSERT(MAIN_CODEWORD_LIMIT >= 9 &&
                      MAIN_CODEWORD_LIMIT <= LZX_MAX_MAIN_CODEWORD_LEN);
-       STATIC_ASSERT(LENGTH_CODEWORD_LIMIT >= 9 &&
+       STATIC_ASSERT(LENGTH_CODEWORD_LIMIT >= 8 &&
                      LENGTH_CODEWORD_LIMIT <= LZX_MAX_LEN_CODEWORD_LEN);
        STATIC_ASSERT(ALIGNED_CODEWORD_LIMIT >= LZX_NUM_ALIGNED_OFFSET_BITS &&
                      ALIGNED_CODEWORD_LIMIT <= LZX_MAX_ALIGNED_CODEWORD_LEN);
@@ -994,6 +996,8 @@ lzx_write_sequences(struct lzx_output_bitstream *os, int block_type,
                        if (!CAN_BUFFER(MAX_MATCH_BITS))
                                lzx_flush_bits(os, ALIGNED_CODEWORD_LIMIT);
                } else {
+                       STATIC_ASSERT(CAN_BUFFER(17));
+
                        lzx_add_bits(os, extra_bits, num_extra_bits);
                        if (!CAN_BUFFER(MAX_MATCH_BITS))
                                lzx_flush_bits(os, 17);
@@ -1709,15 +1713,21 @@ lzx_update_costs(struct lzx_compressor *c)
        unsigned i;
        const struct lzx_lens *lens = &c->codes[c->codes_index].lens;
 
-       for (i = 0; i < c->num_main_syms; i++)
-               c->costs.main[i] = (lens->main[i] ? lens->main[i] : 15) * LZX_BIT_COST;
+       for (i = 0; i < c->num_main_syms; i++) {
+               c->costs.main[i] = (lens->main[i] ? lens->main[i] :
+                                   MAIN_CODEWORD_LIMIT) * LZX_BIT_COST;
+       }
 
-       for (i = 0; i < LZX_LENCODE_NUM_SYMBOLS; i++)
-               c->costs.len[i] = (lens->len[i] ? lens->len[i] : 15) * LZX_BIT_COST;
+       for (i = 0; i < LZX_LENCODE_NUM_SYMBOLS; i++) {
+               c->costs.len[i] = (lens->len[i] ? lens->len[i] :
+                                  LENGTH_CODEWORD_LIMIT) * LZX_BIT_COST;
+       }
 
 #if LZX_CONSIDER_ALIGNED_COSTS
-       for (i = 0; i < LZX_ALIGNEDCODE_NUM_SYMBOLS; i++)
-               c->costs.aligned[i] = (lens->aligned[i] ? lens->aligned[i] : 7) * LZX_BIT_COST;
+       for (i = 0; i < LZX_ALIGNEDCODE_NUM_SYMBOLS; i++) {
+               c->costs.aligned[i] = (lens->aligned[i] ? lens->aligned[i] :
+                                      ALIGNED_CODEWORD_LIMIT) * LZX_BIT_COST;
+       }
 #endif
 
        lzx_compute_match_costs(c);
@@ -1803,7 +1813,7 @@ lzx_compress_near_optimal(struct lzx_compressor *c,
                        if (unlikely(max_len > in_end - in_next)) {
                                max_len = in_end - in_next;
                                nice_len = min(max_len, nice_len);
-                               if (unlikely(max_len < 5)) {
+                               if (unlikely(max_len < BT_MATCHFINDER_REQUIRED_NBYTES)) {
                                        in_next++;
                                        cache_ptr->length = 0;
                                        cache_ptr++;
@@ -1843,7 +1853,7 @@ lzx_compress_near_optimal(struct lzx_compressor *c,
                                        if (unlikely(max_len > in_end - in_next)) {
                                                max_len = in_end - in_next;
                                                nice_len = min(max_len, nice_len);
-                                               if (unlikely(max_len < 5)) {
+                                               if (unlikely(max_len < BT_MATCHFINDER_REQUIRED_NBYTES)) {
                                                        in_next++;
                                                        cache_ptr->length = 0;
                                                        cache_ptr++;