X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;ds=inline;f=src%2Fxpress-compress.c;h=005a0a22452692d47372907255838ed61d8aa81d;hb=45d7e8a4f1740974e1dacd221676f9ec38c6b272;hp=5a314b69356a949c620f4c47e05e01d5f3d64b76;hpb=4757f17833c96b8c83a7e17cbc6f374c449d60db;p=wimlib

diff --git a/src/xpress-compress.c b/src/xpress-compress.c
index 5a314b69..005a0a22 100644
--- a/src/xpress-compress.c
+++ b/src/xpress-compress.c
@@ -36,6 +36,10 @@
 #include "wimlib/util.h"
 #include "wimlib/xpress.h"
 
+#ifdef HAVE_ALLOCA_H
+#  include <alloca.h>
+#endif
+#include <stdlib.h>
 #include <string.h>
 
 /* Intermediate XPRESS match/literal representation.  */
@@ -95,7 +99,7 @@ xpress_write_matches_and_literals(struct output_bitstream *ostream,
 }
 
 struct xpress_record_ctx {
-	freq_t freqs[XPRESS_NUM_SYMBOLS];
+	input_idx_t freqs[XPRESS_NUM_SYMBOLS];
 	struct xpress_match *matches;
 };
 
@@ -132,6 +136,7 @@ xpress_record_match(unsigned len, unsigned offset, void *_ctx)
 static const struct lz_params xpress_lz_params = {
 	.min_match      = XPRESS_MIN_MATCH_LEN,
 	.max_match      = XPRESS_MAX_MATCH_LEN,
+	.max_offset	= XPRESS_MAX_OFFSET,
 	.good_match	= 16,
 	.nice_match     = 32,
 	.max_chain_len  = 16,
@@ -149,8 +154,11 @@ wimlib_xpress_compress(const void * restrict uncompressed_data,
 	struct output_bitstream ostream;
 
 	struct xpress_record_ctx record_ctx;
-	struct xpress_match matches[uncompressed_len];
-	u8 udata[uncompressed_len + 8];
+
+	struct xpress_match *matches;
+	input_idx_t *prev_tab;
+	u8 *udata;
+
 	u16 codewords[XPRESS_NUM_SYMBOLS];
 	u8 lens[XPRESS_NUM_SYMBOLS];
 	input_idx_t num_matches;
@@ -169,6 +177,21 @@ wimlib_xpress_compress(const void * restrict uncompressed_data,
 	if (uncompressed_len < XPRESS_NUM_SYMBOLS / 2 + 1 + 4)
 		return 0;
 
+	if (uncompressed_len <= STACK_MAX) {
+		matches = alloca(uncompressed_len * sizeof(matches[0]));
+		udata = alloca(uncompressed_len + 8);
+		prev_tab = alloca(uncompressed_len * sizeof(prev_tab[0]));
+	} else {
+		matches = MALLOC(uncompressed_len * sizeof(matches[0]));
+		udata = MALLOC(uncompressed_len + 8);
+		prev_tab = MALLOC(uncompressed_len * sizeof(prev_tab[0]));
+		if (matches == NULL || udata == NULL || prev_tab == NULL) {
+			WARNING("Failed to allocate memory for compression...");
+			compressed_len = 0;
+			goto out_free;
+		}
+	}
+
 	/* Copy the data to a temporary buffer, but only to avoid
 	 * inconsequential accesses of uninitialized memory in
 	 * lz_analyze_block().  */
@@ -183,7 +206,8 @@ wimlib_xpress_compress(const void * restrict uncompressed_data,
 			 xpress_record_match,
 			 xpress_record_literal,
 			 &record_ctx,
-			 &xpress_lz_params);
+			 &xpress_lz_params,
+			 prev_tab);
 
 	num_matches = (record_ctx.matches - matches);
 
@@ -206,11 +230,13 @@ wimlib_xpress_compress(const void * restrict uncompressed_data,
 
 	/* Flush any pending data and get the length of the compressed data.  */
 	compressed_len = flush_output_bitstream(&ostream);
-	if (compressed_len == ~(input_idx_t)0)
-		return 0;
+	if (compressed_len == ~(input_idx_t)0) {
+		compressed_len = 0;
+		goto out_free;
+	}
 	compressed_len += XPRESS_NUM_SYMBOLS / 2;
 
-#if defined(ENABLE_XPRESS_DEBUG) || defined(ENABLE_VERIFY_COMPRESSION) || 1
+#if defined(ENABLE_XPRESS_DEBUG) || defined(ENABLE_VERIFY_COMPRESSION)
 	/* Verify that we really get the same thing back when decompressing.  */
 	if (wimlib_xpress_decompress(compressed_data, compressed_len,
 				     udata, uncompressed_len))
@@ -218,15 +244,24 @@ wimlib_xpress_compress(const void * restrict uncompressed_data,
 		ERROR("Failed to decompress data we "
 		      "compressed using XPRESS algorithm");
 		wimlib_assert(0);
-		return 0;
+		compressed_len = 0;
+		goto out_free;
 	}
 
 	if (memcmp(uncompressed_data, udata, uncompressed_len)) {
 		ERROR("Data we compressed using XPRESS algorithm "
 		      "didn't decompress to original");
 		wimlib_assert(0);
-		return 0;
+		compressed_len = 0;
+		goto out_free;
 	}
 #endif
+
+out_free:
+	if (uncompressed_len > STACK_MAX) {
+		FREE(matches);
+		FREE(udata);
+		FREE(prev_tab);
+	}
 	return compressed_len;
 }