X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Fxpress-decompress.c;h=855f2cb311ccb156db1ecd9e00600c86255e458a;hp=f08cccbb4b405372b4a4bbb15018973ed7337875;hb=90f461637225b29f3b0ee9fa3862cff4ecb56ad8;hpb=e176e9731e696562bab8de7b9bd34c019deef3e8

diff --git a/src/xpress-decompress.c b/src/xpress-decompress.c
index f08cccbb..855f2cb3 100644
--- a/src/xpress-decompress.c
+++ b/src/xpress-decompress.c
@@ -70,7 +70,8 @@
 #endif
 
 #include "wimlib.h"
-#include "wimlib/decompress.h"
+#include "wimlib/decompressor_ops.h"
+#include "wimlib/decompress_common.h"
 #include "wimlib/xpress.h"
 
 /*
@@ -89,9 +90,8 @@ xpress_decode_match(unsigned sym, input_idx_t window_pos,
 		    struct input_bitstream * restrict istream)
 {
 
-	u8 len_hdr;
-	u8 offset_bsr;
-	int ret;
+	unsigned len_hdr;
+	unsigned offset_bsr;
 	u8 *match_dest;
 	u8 *match_src;
 	unsigned i;
@@ -102,27 +102,15 @@ xpress_decode_match(unsigned sym, input_idx_t window_pos,
 	len_hdr = sym & 0xf;
 	offset_bsr = sym >> 4;
 
-	if (bitstream_ensure_bits(istream, 16))
-		return -1;
+	bitstream_ensure_bits(istream, 16);
 
 	match_offset = (1U << offset_bsr) | bitstream_pop_bits(istream, offset_bsr);
 
 	if (len_hdr == 0xf) {
-		ret = bitstream_read_byte(istream);
-		if (ret < 0)
-			return ret;
-		match_len = ret;
+		match_len = bitstream_read_byte(istream);
 		if (unlikely(match_len == 0xff)) {
-			ret = bitstream_read_byte(istream);
-			if (ret < 0)
-				return ret;
-			match_len = ret;
-
-			ret = bitstream_read_byte(istream);
-			if (ret < 0)
-				return ret;
-
-			match_len |= (ret << 8);
+			match_len = bitstream_read_byte(istream);
+			match_len |= (unsigned)bitstream_read_byte(istream) << 8;
 		} else {
 			match_len += 0xf;
 		}
@@ -132,7 +120,7 @@ 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 the current
+	/* Verify the match is in bounds, then copy its data to the current
 	 * position.  */
 
 	if (window_pos + match_len > window_len)
@@ -156,7 +144,6 @@ 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;
@@ -166,14 +153,10 @@ xpress_lz_decode(struct input_bitstream * restrict istream,
 		unsigned sym;
 		int ret;
 
-		if (unlikely(bitstream_ensure_bits(istream, 16)))
-			return -1;
-
-		if (unlikely(read_huffsym(istream, decode_table, lens,
-					  XPRESS_NUM_SYMBOLS, XPRESS_TABLEBITS,
-					  &sym, XPRESS_MAX_CODEWORD_LEN)))
-			return -1;
+		bitstream_ensure_bits(istream, 16);
 
+		sym = read_huffsym(istream, decode_table,
+				   XPRESS_TABLEBITS, XPRESS_MAX_CODEWORD_LEN);
 		if (sym < XPRESS_NUM_CHARS) {
 			/* Literal  */
 			uncompressed_data[curpos] = sym;
@@ -194,14 +177,11 @@ xpress_lz_decode(struct input_bitstream * restrict istream,
 }
 
 
-/* API function documented in wimlib.h  */
-WIMLIBAPI int
-wimlib_xpress_decompress(const void * const restrict _compressed_data,
-			 const unsigned compressed_len,
-			 void * const restrict uncompressed_data,
-			 const unsigned uncompressed_len)
+static int
+xpress_decompress(const void *compressed_data, size_t compressed_size,
+		  void *uncompressed_data, size_t uncompressed_size, void *_ctx)
 {
-	const u8 *compressed_data = _compressed_data;
+	const u8 *cdata = compressed_data;
 	u8 lens[XPRESS_NUM_SYMBOLS];
 	u8 *lens_p;
 	u16 decode_table[(1 << XPRESS_TABLEBITS) + 2 * XPRESS_NUM_SYMBOLS]
@@ -211,13 +191,13 @@ wimlib_xpress_decompress(const void * const restrict _compressed_data,
 	/* XPRESS uses only one Huffman code.  It contains 512 symbols, and the
 	 * code lengths of these symbols are given literally as 4-bit integers
 	 * in the first 256 bytes of the compressed data.  */
-	if (compressed_len < XPRESS_NUM_SYMBOLS / 2)
+	if (compressed_size < XPRESS_NUM_SYMBOLS / 2)
 		return -1;
 
 	lens_p = lens;
 	for (unsigned i = 0; i < XPRESS_NUM_SYMBOLS / 2; i++) {
-		*lens_p++ = compressed_data[i] & 0xf;
-		*lens_p++ = compressed_data[i] >> 4;
+		*lens_p++ = cdata[i] & 0xf;
+		*lens_p++ = cdata[i] >> 4;
 	}
 
 	if (make_huffman_decode_table(decode_table, XPRESS_NUM_SYMBOLS,
@@ -225,9 +205,13 @@ wimlib_xpress_decompress(const void * const restrict _compressed_data,
 				      XPRESS_MAX_CODEWORD_LEN))
 		return -1;
 
-	init_input_bitstream(&istream, compressed_data + XPRESS_NUM_SYMBOLS / 2,
-			     compressed_len - XPRESS_NUM_SYMBOLS / 2);
+	init_input_bitstream(&istream, cdata + XPRESS_NUM_SYMBOLS / 2,
+			     compressed_size - XPRESS_NUM_SYMBOLS / 2);
 
 	return xpress_lz_decode(&istream, uncompressed_data,
-				uncompressed_len, lens, decode_table);
+				uncompressed_size, decode_table);
 }
+
+const struct decompressor_ops xpress_decompressor_ops = {
+	.decompress = xpress_decompress,
+};