xpress-compress.c: Rename xpress_match => xpress_item
authorEric Biggers <ebiggers3@gmail.com>
Sat, 5 Jul 2014 02:22:01 +0000 (21:22 -0500)
committerEric Biggers <ebiggers3@gmail.com>
Sat, 5 Jul 2014 02:22:01 +0000 (21:22 -0500)
src/xpress-compress.c

index e505104..46f683f 100644 (file)
@@ -7,7 +7,7 @@
  */
 
 /*
- * Copyright (C) 2012, 2013 Eric Biggers
+ * Copyright (C) 2012, 2013, 2014 Eric Biggers
  *
  * This file is part of wimlib, a library for working with WIM files.
  *
 
 struct xpress_record_ctx {
        u32 freqs[XPRESS_NUM_SYMBOLS];
-       struct xpress_match *matches;
+       struct xpress_item *chosen_items;
 };
 
 struct xpress_compressor {
        u8 *window;
        u32 max_window_size;
-       struct xpress_match *matches;
+       struct xpress_item *chosen_items;
        u32 *prev_tab;
        u32 codewords[XPRESS_NUM_SYMBOLS];
        u8 lens[XPRESS_NUM_SYMBOLS];
@@ -56,7 +56,7 @@ struct xpress_compressor {
 };
 
 /* Intermediate XPRESS match/literal representation.  */
-struct xpress_match {
+struct xpress_item {
        u16 adjusted_len;  /* Match length minus XPRESS_MIN_MATCH_LEN */
        u16 offset;        /* Match offset */
        /* For literals, offset == 0 and adjusted_len is the literal.  */
@@ -69,7 +69,7 @@ struct xpress_match {
  * @codewords and @lens provide the Huffman code that is being used.
  */
 static void
-xpress_write_match(struct xpress_match match,
+xpress_write_match(struct xpress_item match,
                   struct output_bitstream *restrict ostream,
                   const u32 codewords[restrict],
                   const u8 lens[restrict])
@@ -92,19 +92,19 @@ xpress_write_match(struct xpress_match match,
 }
 
 static void
-xpress_write_matches_and_literals(struct output_bitstream *ostream,
-                                 const struct xpress_match matches[restrict],
-                                 u32 num_matches,
-                                 const u32 codewords[restrict],
-                                 const u8 lens[restrict])
+xpress_write_items(struct output_bitstream *ostream,
+                  const struct xpress_item items[restrict],
+                  u32 num_items,
+                  const u32 codewords[restrict],
+                  const u8 lens[restrict])
 {
-       for (u32 i = 0; i < num_matches; i++) {
-               if (matches[i].offset) {
-                       /* Real match  */
-                       xpress_write_match(matches[i], ostream, codewords, lens);
+       for (u32 i = 0; i < num_items; i++) {
+               if (items[i].offset) {
+                       /* Match  */
+                       xpress_write_match(items[i], ostream, codewords, lens);
                } else {
-                       /* Literal byte  */
-                       u8 lit = matches[i].adjusted_len;
+                       /* Literal  */
+                       u8 lit = items[i].adjusted_len;
                        bitstream_put_bits(ostream, codewords[lit], lens[lit]);
                }
        }
@@ -116,7 +116,8 @@ xpress_record_literal(u8 lit, void *_ctx)
 {
        struct xpress_record_ctx *ctx = _ctx;
        ctx->freqs[lit]++;
-       *(ctx->matches++) = (struct xpress_match) { .offset = 0, .adjusted_len = lit };
+       *(ctx->chosen_items++) =
+               (struct xpress_item) { .offset = 0, .adjusted_len = lit };
 }
 
 static void
@@ -137,8 +138,9 @@ xpress_record_match(unsigned len, unsigned offset, void *_ctx)
        XPRESS_ASSERT(sym < XPRESS_NUM_SYMBOLS);
 
        ctx->freqs[sym]++;
-       *(ctx->matches++) = (struct xpress_match) { .offset = offset,
-                                                   .adjusted_len = adjusted_len };
+       *(ctx->chosen_items++) =
+               (struct xpress_item) { .offset = offset,
+                                      .adjusted_len = adjusted_len };
 }
 
 static const struct lz_params xpress_lz_params = {
@@ -159,7 +161,7 @@ xpress_compress(const void *uncompressed_data, size_t uncompressed_size,
        struct xpress_compressor *c = _c;
        u8 *cptr = compressed_data;
        struct output_bitstream ostream;
-       u32 num_matches;
+       u32 num_chosen_items;
        u32 i;
        size_t compressed_size;
 
@@ -183,7 +185,7 @@ xpress_compress(const void *uncompressed_data, size_t uncompressed_size,
 
        /* Determine match/literal sequence to divide the data into.  */
        memset(c->record_ctx.freqs, 0, sizeof(c->record_ctx.freqs));
-       c->record_ctx.matches = c->matches;
+       c->record_ctx.chosen_items = c->chosen_items;
        lz_analyze_block(c->window,
                         uncompressed_size,
                         xpress_record_match,
@@ -192,7 +194,7 @@ xpress_compress(const void *uncompressed_data, size_t uncompressed_size,
                         &xpress_lz_params,
                         c->prev_tab);
 
-       num_matches = (c->record_ctx.matches - c->matches);
+       num_chosen_items = (c->record_ctx.chosen_items - c->chosen_items);
 
        /* Account for end of data symbol.  */
        c->record_ctx.freqs[XPRESS_END_OF_DATA]++;
@@ -209,8 +211,8 @@ xpress_compress(const void *uncompressed_data, size_t uncompressed_size,
        init_output_bitstream(&ostream, cptr,
                              compressed_size_avail - XPRESS_NUM_SYMBOLS / 2 - 1);
 
-       xpress_write_matches_and_literals(&ostream, c->matches,
-                                         num_matches, c->codewords, c->lens);
+       xpress_write_items(&ostream, c->chosen_items, num_chosen_items,
+                          c->codewords, c->lens);
 
        /* Flush any pending data and get the length of the compressed data.  */
        compressed_size = flush_output_bitstream(&ostream);
@@ -268,7 +270,7 @@ xpress_free_compressor(void *_c)
 
        if (c) {
                FREE(c->window);
-               FREE(c->matches);
+               FREE(c->chosen_items);
                FREE(c->prev_tab);
                FREE(c);
        }
@@ -294,8 +296,8 @@ xpress_create_compressor(size_t max_window_size,
 
        c->max_window_size = max_window_size;
 
-       c->matches = MALLOC(max_window_size * sizeof(c->matches[0]));
-       if (c->matches == NULL)
+       c->chosen_items = MALLOC(max_window_size * sizeof(c->chosen_items[0]));
+       if (c->chosen_items == NULL)
                goto oom;
 
        c->prev_tab = MALLOC(max_window_size * sizeof(c->prev_tab[0]));
@@ -318,7 +320,7 @@ xpress_get_needed_memory(size_t max_window_size,
 
        size += sizeof(struct xpress_compressor);
        size += max_window_size + 8;
-       size += max_window_size * sizeof(((struct xpress_compressor*)0)->matches[0]);
+       size += max_window_size * sizeof(((struct xpress_compressor*)0)->chosen_items[0]);
        size += max_window_size * sizeof(((struct xpress_compressor*)0)->prev_tab[0]);
 
        return size;