Update LZMS match-choosing

[wimlib] / include / wimlib / lz_optimal.h

diff --git a/include/wimlib/lz_optimal.h b/include/wimlib/lz_optimal.h
index 797ba096d464a57efaa51ef2373dea20a1c9376f..98eec10386d8fdab5bf548af2a58f414bb20d7cc 100644 (file)
--- a/include/wimlib/lz_optimal.h
+++ b/include/wimlib/lz_optimal.h
@@ -195,9 +195,11 @@ typedef u32 (*lz_get_matches_t)(LZ_COMPRESSOR *ctx,
 typedef void (*lz_skip_bytes_t)(LZ_COMPRESSOR *ctx, input_idx_t n);
 
 /* Get the cost of the literal located at the position at which matches have
- * most recently been searched.  Note: this currently assumes that literals do
- * not affect the LZ_FORMAT_STATE.  */
-typedef u32 (lz_get_prev_literal_cost_t)(LZ_COMPRESSOR *ctx);
+ * most recently been searched.  This can optionally update the @state to take
+ * into account format-dependent state that affects match costs, such as repeat
+ * offsets.  */
+typedef u32 (lz_get_prev_literal_cost_t)(LZ_COMPRESSOR *ctx,
+                                        LZ_FORMAT_STATE *state);
 
 /* Get the cost of a match.  This can optionally update the @state to take into
  * account format-dependent state that affects match costs, such as repeat
@@ -294,7 +296,7 @@ lz_get_near_optimal_match(struct lz_match_chooser *mc,
         * literal.  */
        mc->optimum[0].state = *initial_state;
        mc->optimum[1].state = mc->optimum[0].state;
-       mc->optimum[1].cost = (*get_prev_literal_cost)(ctx);
+       mc->optimum[1].cost = (*get_prev_literal_cost)(ctx, &mc->optimum[1].state);
        mc->optimum[1].prev.link = 0;
 
        /* Calculate the cost to reach any position up to and including that
@@ -364,12 +366,14 @@ lz_get_near_optimal_match(struct lz_match_chooser *mc,
 
                /* Consider proceeding with a literal byte.  */
                lz_mc_cost_t cur_cost = mc->optimum[cur_pos].cost;
+               LZ_FORMAT_STATE cur_plus_literal_state = mc->optimum[cur_pos].state;
                lz_mc_cost_t cur_plus_literal_cost = cur_cost +
-                               (*get_prev_literal_cost)(ctx);
+                               (*get_prev_literal_cost)(ctx,
+                                                        &cur_plus_literal_state);
                if (cur_plus_literal_cost < mc->optimum[cur_pos + 1].cost) {
                        mc->optimum[cur_pos + 1].cost = cur_plus_literal_cost;
                        mc->optimum[cur_pos + 1].prev.link = cur_pos;
-                       mc->optimum[cur_pos + 1].state = mc->optimum[cur_pos].state;
+                       mc->optimum[cur_pos + 1].state = cur_plus_literal_state;
                }
 
                if (num_possible_matches == 0)
@@ -383,7 +387,7 @@ lz_get_near_optimal_match(struct lz_match_chooser *mc,
                for (input_idx_t len = 2, match_idx = num_possible_matches - 1;
                     len <= new_len; len++)
                {
-                       LZX_ASSERT(match_idx < num_possible_matches);
+                       LZ_ASSERT(match_idx < num_possible_matches);
 
                        LZ_FORMAT_STATE state = mc->optimum[cur_pos].state;
                        lz_mc_cost_t cost;