X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;f=src%2Fxpress-decompress.c;h=f060d0b0df2afeccfec25fbae91d41321f6beda6;hb=965c28d0cce2e43df3c38b47c78204b1c33c313d;hp=338c9d957b7a90bccd55f29447a3add8797ab806;hpb=18f9daee201c3e79e6d508f1ce69206b8035ae4b;p=wimlib

diff --git a/src/xpress-decompress.c b/src/xpress-decompress.c
index 338c9d95..f060d0b0 100644
--- a/src/xpress-decompress.c
+++ b/src/xpress-decompress.c
@@ -69,7 +69,6 @@
 #  include "config.h"
 #endif
 
-#include "wimlib.h"
 #include "wimlib/decompressor_ops.h"
 #include "wimlib/decompress_common.h"
 #include "wimlib/xpress.h"
@@ -85,16 +84,12 @@
  * Returns the match length, or -1 if the data is invalid.
  */
 static int
-xpress_decode_match(unsigned sym, input_idx_t window_pos,
-		    input_idx_t window_len, u8 window[restrict],
+xpress_decode_match(unsigned sym, u32 window_pos,
+		    u32 window_len, u8 window[restrict],
 		    struct input_bitstream * restrict istream)
 {
-
-	u8 len_hdr;
-	u8 offset_bsr;
-	u8 *match_dest;
-	u8 *match_src;
-	unsigned i;
+	unsigned len_hdr;
+	unsigned offset_bsr;
 	unsigned match_len;
 	unsigned match_offset;
 
@@ -119,21 +114,14 @@ xpress_decode_match(unsigned sym, input_idx_t window_pos,
 	}
 	match_len += XPRESS_MIN_MATCH_LEN;
 
-
-	/* Verify the match is in bounds, then copy its data to the current
-	 * position.  */
-
-	if (window_pos + match_len > window_len)
+	if (unlikely(match_len > window_len - window_pos))
 		return -1;
 
-	if (match_offset > window_pos)
+	if (unlikely(match_offset > window_pos))
 		return -1;
 
-	match_dest = window + window_pos;
-	match_src = match_dest - match_offset;
-
-	for (i = 0; i < match_len; i++)
-		match_dest[i] = match_src[i];
+	lz_copy(&window[window_pos], match_len, match_offset,
+		&window[window_len]);
 
 	return match_len;
 }
@@ -144,18 +132,15 @@ static int
 xpress_lz_decode(struct input_bitstream * restrict istream,
 		 u8 uncompressed_data[restrict],
 		 unsigned uncompressed_len,
-		 const u8 lens[restrict],
 		 const u16 decode_table[restrict])
 {
-	input_idx_t curpos;
+	u32 curpos;
 	unsigned match_len;
 
 	for (curpos = 0; curpos < uncompressed_len; curpos += match_len) {
 		unsigned sym;
 		int ret;
 
-		bitstream_ensure_bits(istream, 16);
-
 		sym = read_huffsym(istream, decode_table,
 				   XPRESS_TABLEBITS, XPRESS_MAX_CODEWORD_LEN);
 		if (sym < XPRESS_NUM_CHARS) {
@@ -210,7 +195,7 @@ xpress_decompress(const void *compressed_data, size_t compressed_size,
 			     compressed_size - XPRESS_NUM_SYMBOLS / 2);
 
 	return xpress_lz_decode(&istream, uncompressed_data,
-				uncompressed_size, lens, decode_table);
+				uncompressed_size, decode_table);
 }
 
 const struct decompressor_ops xpress_decompressor_ops = {