fix: breakpad use miniz

third_party/zlib-ng/deflate_slow.c

@@ -0,0 +1,144 @@
+/* deflate_slow.c -- compress data using the slow strategy of deflation algorithm
+ *
+ * Copyright (C) 1995-2024 Jean-loup Gailly and Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "zbuild.h"
+#include "deflate.h"
+#include "deflate_p.h"
+#include "functable.h"
+
+/* ===========================================================================
+ * Same as deflate_medium, 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.
+ */
+Z_INTERNAL block_state deflate_slow(deflate_state *s, int flush) {
+    Pos hash_head;           /* head of hash chain */
+    int bflush;              /* set if current block must be flushed */
+    int64_t dist;
+    uint32_t match_len;
+    match_func longest_match;
+
+    if (s->max_chain_length <= 1024)
+        longest_match = FUNCTABLE_FPTR(longest_match);
+    else
+        longest_match = FUNCTABLE_FPTR(longest_match_slow);
+
+    /* Process the input block. */
+    for (;;) {
+        /* Make sure that we always have enough lookahead, except
+         * at the end of the input file. We need STD_MAX_MATCH bytes
+         * for the next match, plus WANT_MIN_MATCH bytes to insert the
+         * string following the next match.
+         */
+        if (s->lookahead < MIN_LOOKAHEAD) {
+            PREFIX(fill_window)(s);
+            if (UNLIKELY(s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH)) {
+                return need_more;
+            }
+            if (UNLIKELY(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 = 0;
+        if (LIKELY(s->lookahead >= WANT_MIN_MATCH)) {
+            hash_head = s->quick_insert_string(s, s->strstart);
+        }
+
+        /* Find the longest match, discarding those <= prev_length.
+         */
+        s->prev_match = (Pos)s->match_start;
+        match_len = STD_MIN_MATCH - 1;
+        dist = (int64_t)s->strstart - hash_head;
+
+        if (dist <= MAX_DIST(s) && dist > 0 && s->prev_length < s->max_lazy_match && hash_head != 0) {
+            /* 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).
+             */
+            match_len = longest_match(s, hash_head);
+            /* longest_match() sets match_start */
+
+            if (match_len <= 5 && (s->strategy == Z_FILTERED)) {
+                /* If prev_match is also WANT_MIN_MATCH, match_start is garbage
+                 * but we will ignore the current match anyway.
+                 */
+                match_len = STD_MIN_MATCH - 1;
+            }
+        }
+        /* If there was a match at the previous step and the current
+         * match is not better, output the previous match:
+         */
+        if (s->prev_length >= STD_MIN_MATCH && match_len <= s->prev_length) {
+            unsigned int max_insert = s->strstart + s->lookahead - STD_MIN_MATCH;
+            /* Do not insert strings in hash table beyond this. */
+
+            Assert((s->strstart-1) <= UINT16_MAX, "strstart-1 should fit in uint16_t");
+            check_match(s, (Pos)(s->strstart - 1), s->prev_match, s->prev_length);
+
+            bflush = zng_tr_tally_dist(s, s->strstart -1 - s->prev_match, s->prev_length - STD_MIN_MATCH);
+
+            /* 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->prev_length -= 1;
+            s->lookahead -= s->prev_length;
+
+            unsigned int mov_fwd = s->prev_length - 1;
+            if (max_insert > s->strstart) {
+                unsigned int insert_cnt = mov_fwd;
+                if (UNLIKELY(insert_cnt > max_insert - s->strstart))
+                    insert_cnt = max_insert - s->strstart;
+                s->insert_string(s, s->strstart + 1, insert_cnt);
+            }
+            s->prev_length = 0;
+            s->match_available = 0;
+            s->strstart += mov_fwd + 1;
+
+            if (UNLIKELY(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.
+             */
+            bflush = zng_tr_tally_lit(s, s->window[s->strstart-1]);
+            if (UNLIKELY(bflush))
+                FLUSH_BLOCK_ONLY(s, 0);
+            s->prev_length = match_len;
+            s->strstart++;
+            s->lookahead--;
+            if (UNLIKELY(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->prev_length = match_len;
+            s->match_available = 1;
+            s->strstart++;
+            s->lookahead--;
+        }
+    }
+    Assert(flush != Z_NO_FLUSH, "no flush?");
+    if (UNLIKELY(s->match_available)) {
+        Z_UNUSED(zng_tr_tally_lit(s, s->window[s->strstart-1]));
+        s->match_available = 0;
+    }
+    s->insert = s->strstart < (STD_MIN_MATCH - 1) ? s->strstart : (STD_MIN_MATCH - 1);
+    if (UNLIKELY(flush == Z_FINISH)) {
+        FLUSH_BLOCK(s, 1);
+        return finish_done;
+    }
+    if (UNLIKELY(s->sym_next))
+        FLUSH_BLOCK(s, 0);
+    return block_done;
+}