zlib/SOURCES/zlib-1.2.11-Limit-hash-table-inserts.patch
2023-03-29 11:49:24 +00:00

70 lines
2.6 KiB
Diff

From 2d80d3f6b52f9fa454c26c89d2d6a1790e1cecb0 Mon Sep 17 00:00:00 2001
From: Mark Adler <madler@alumni.caltech.edu>
Date: Sat, 21 Jan 2017 01:50:26 -0800
Subject: [PATCH] Limit hash table inserts after switch from stored deflate.
This limits hash table inserts to the available data in the window
and to the sliding window size in deflate_stored(). The hash table
inserts are deferred until deflateParams() switches to a non-zero
compression level.
---
deflate.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/deflate.c b/deflate.c
index 20bda4f..d368b25 100644
--- a/deflate.c
+++ b/deflate.c
@@ -1513,6 +1513,8 @@ local void fill_window(s)
s->match_start -= wsize;
s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
s->block_start -= (long) wsize;
+ if (s->insert > s->strstart)
+ s->insert = s->strstart;
slide_hash(s);
more += wsize;
}
@@ -1742,6 +1744,7 @@ local block_state deflate_stored(s, flush)
s->matches = 2; /* clear hash */
zmemcpy(s->window, s->strm->next_in - s->w_size, s->w_size);
s->strstart = s->w_size;
+ s->insert = s->strstart;
}
else {
if (s->window_size - s->strstart <= used) {
@@ -1750,12 +1753,14 @@ local block_state deflate_stored(s, flush)
zmemcpy(s->window, s->window + s->w_size, s->strstart);
if (s->matches < 2)
s->matches++; /* add a pending slide_hash() */
+ if (s->insert > s->strstart)
+ s->insert = s->strstart;
}
zmemcpy(s->window + s->strstart, s->strm->next_in - used, used);
s->strstart += used;
+ s->insert += MIN(used, s->w_size - s->insert);
}
s->block_start = s->strstart;
- s->insert += MIN(used, s->w_size - s->insert);
}
if (s->high_water < s->strstart)
s->high_water = s->strstart;
@@ -1779,12 +1784,15 @@ local block_state deflate_stored(s, flush)
if (s->matches < 2)
s->matches++; /* add a pending slide_hash() */
have += s->w_size; /* more space now */
+ if (s->insert > s->strstart)
+ s->insert = s->strstart;
}
if (have > s->strm->avail_in)
have = s->strm->avail_in;
if (have) {
read_buf(s->strm, s->window + s->strstart, have);
s->strstart += have;
+ s->insert += MIN(have, s->w_size - s->insert);
}
if (s->high_water < s->strstart)
s->high_water = s->strstart;
--
2.39.1