/* Allocated size of @cur_window. */
u32 max_window_size;
+ /* log2 order of the LZX window size for LZ match offset encoding
+ * purposes. Will be >= LZX_MIN_WINDOW_ORDER and <=
+ * LZX_MAX_WINDOW_ORDER.
+ *
+ * Note: 1 << @window_order is normally equal to @max_window_size, but
+ * it will be greater than @max_window_size in the event that the
+ * compressor was created with a non-power-of-2 block size. (See
+ * lzx_get_window_order().) */
+ unsigned window_order;
+
/* Compression parameters. */
struct lzx_compressor_params params;
unsigned (*get_matches_func)(struct lzx_compressor *, const struct lz_match **);
void (*skip_bytes_func)(struct lzx_compressor *, unsigned n);
- /* Number of symbols in the main alphabet (depends on the
- * @max_window_size since it determines the maximum allowed offset). */
+ /* Number of symbols in the main alphabet (depends on the @window_order
+ * since it determines the maximum allowed offset). */
unsigned num_main_syms;
/* The current match offset LRU queue. */
static void
lzx_write_compressed_block(int block_type,
u32 block_size,
- u32 max_window_size,
+ unsigned window_order,
unsigned num_main_syms,
struct lzx_item * chosen_items,
u32 num_chosen_items,
} else {
lzx_write_bits(os, 0, 1);
- if (max_window_size >= 65536)
+ if (window_order >= 16)
lzx_write_bits(os, block_size >> 16, 8);
lzx_write_bits(os, block_size & 0xFFFF, 16);
lzx_write_compressed_block(spec->block_type,
spec->block_size,
- c->max_window_size,
+ c->window_order,
c->num_main_syms,
spec->chosen_items,
spec->num_chosen_items,
lzx_free_compressor(void *_c);
static u64
-lzx_get_needed_memory(size_t max_window_size, unsigned int compression_level)
+lzx_get_needed_memory(size_t max_block_size, unsigned int compression_level)
{
struct lzx_compressor_params params;
u64 size = 0;
+ unsigned window_order;
+ u32 max_window_size;
- if (!lzx_window_size_valid(max_window_size))
+ window_order = lzx_get_window_order(max_block_size);
+ if (window_order == 0)
return 0;
+ max_window_size = max_block_size;
lzx_build_params(compression_level, max_window_size, ¶ms);
}
static int
-lzx_create_compressor(size_t max_window_size, unsigned int compression_level,
+lzx_create_compressor(size_t max_block_size, unsigned int compression_level,
void **c_ret)
{
struct lzx_compressor *c;
struct lzx_compressor_params params;
struct lz_mf_params mf_params;
+ unsigned window_order;
+ u32 max_window_size;
- if (!lzx_window_size_valid(max_window_size))
+ window_order = lzx_get_window_order(max_block_size);
+ if (window_order == 0)
return WIMLIB_ERR_INVALID_PARAM;
+ max_window_size = max_block_size;
lzx_build_params(compression_level, max_window_size, ¶ms);
lzx_build_mf_params(¶ms, max_window_size, &mf_params);
goto oom;
c->params = params;
- c->num_main_syms = lzx_get_num_main_syms(max_window_size);
+ c->num_main_syms = lzx_get_num_main_syms(window_order);
c->max_window_size = max_window_size;
+ c->window_order = window_order;
c->cur_window = ALIGNED_MALLOC(max_window_size, 16);
if (!c->cur_window)