Style

[wimlib] / src / xpress-compress.c

diff --git a/src/xpress-compress.c b/src/xpress-compress.c
index 77df527994483f7062bfadab49f14405456b74cd..6d2836f050e6b3b02f86c3b0b3c6410a2324d292 100644 (file)
--- a/src/xpress-compress.c
+++ b/src/xpress-compress.c
@@ -7,7 +7,7 @@
  */
 
 /*
- * Copyright (C) 2012 Eric Biggers
+ * Copyright (C) 2012, 2013 Eric Biggers
  *
  * This file is part of wimlib, a library for working with WIM files.
  *
@@ -36,8 +36,9 @@
  *
  * @codewords and @lens provide the Huffman code that is being used.
  */
-static int xpress_write_match(struct output_bitstream *ostream, u32 match,
-                             const u16 codewords[], const u8 lens[])
+static int
+xpress_write_match(struct output_bitstream *ostream, u32 match,
+                  const u16 codewords[], const u8 lens[])
 {
        u32 adjusted_match_len = match & 0xffff;
        u32 match_offset = match >> 16;
@@ -65,11 +66,12 @@ static int xpress_write_match(struct output_bitstream *ostream, u32 match,
                                  match_offset ^ (1 << offset_bsr), offset_bsr);
 }
 
-static int xpress_write_compressed_literals(struct output_bitstream *ostream,
-                                           const u32 match_tab[],
-                                           unsigned num_matches,
-                                           const u16 codewords[],
-                                           const u8 lens[])
+static int
+xpress_write_compressed_literals(struct output_bitstream *ostream,
+                                const u32 match_tab[],
+                                unsigned num_matches,
+                                const u16 codewords[],
+                                const u8 lens[])
 {
        for (unsigned i = 0; i < num_matches; i++) {
                int ret;
@@ -88,15 +90,17 @@ static int xpress_write_compressed_literals(struct output_bitstream *ostream,
                                  lens[XPRESS_END_OF_DATA]);
 }
 
-static u32 xpress_record_literal(u8 literal, void *__freq_tab)
+static u32
+xpress_record_literal(u8 literal, void *__freq_tab)
 {
-       u32 *freq_tab = __freq_tab;
+       freq_t *freq_tab = __freq_tab;
        freq_tab[literal]++;
        return literal;
 }
 
-static u32 xpress_record_match(unsigned match_offset, unsigned match_len,
-                              void *freq_tab, void *ignore)
+static u32
+xpress_record_match(unsigned match_offset, unsigned match_len,
+                   void *freq_tab, void *ignore)
 {
        wimlib_assert(match_len >= XPRESS_MIN_MATCH &&
                      match_len <= XPRESS_MAX_MATCH);
@@ -121,7 +125,7 @@ static u32 xpress_record_match(unsigned match_offset, unsigned match_len,
        u32 len_hdr = min(adjusted_match_len, 0xf);
        u32 offset_bsr = bsr32(match_offset);
        u32 sym = len_hdr | (offset_bsr << 4) | XPRESS_NUM_CHARS;
-       ((u32*)freq_tab)[sym]++;
+       ((freq_t*)freq_tab)[sym]++;
        return adjusted_match_len | (match_offset << 16);
 }
 
@@ -152,14 +156,15 @@ static const struct lz_params xpress_lz_params = {
  * not reduce its size, and @compressed_data will not contain the full
  * compressed data.
  */
-int xpress_compress(const void *__uncompressed_data, unsigned uncompressed_len,
-                   void *__compressed_data, unsigned *compressed_len_ret)
+int
+xpress_compress(const void *__uncompressed_data, unsigned uncompressed_len,
+               void *__compressed_data, unsigned *compressed_len_ret)
 {
        const u8 *uncompressed_data = __uncompressed_data;
        u8 *compressed_data = __compressed_data;
        struct output_bitstream ostream;
        u32 match_tab[uncompressed_len];
-       u32 freq_tab[XPRESS_NUM_SYMBOLS];
+       freq_t freq_tab[XPRESS_NUM_SYMBOLS];
        u16 codewords[XPRESS_NUM_SYMBOLS];
        u8 lens[XPRESS_NUM_SYMBOLS];
        unsigned num_matches;
@@ -169,8 +174,14 @@ int xpress_compress(const void *__uncompressed_data, unsigned uncompressed_len,
 
        /* XPRESS requires 256 bytes of overhead for the Huffman tables, so it's
         * impossible cannot compress 256 bytes or less of data to less than the
-        * input size. */
-       if (uncompressed_len <= XPRESS_NUM_SYMBOLS / 2)
+        * input size.
+        *
+        * +1 to take into account that the buffer for compressed data is 1 byte
+        * smaller than the buffer for uncompressed data.
+        *
+        * +4 to take into account that init_output_bitstream() requires at
+        * least 4 bytes of data. */
+       if (uncompressed_len < XPRESS_NUM_SYMBOLS / 2 + 1 + 4)
                return 1;
 
        ZERO_ARRAY(freq_tab);