X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;ds=sidebyside;f=src%2Flzx_common.c;h=0677e0a0d40693a37888c431b521771621ad60e1;hb=ce50e9190bdb770640a53a1a8d612229be65d8e7;hp=3cc6981b186926ebef22bd63633153a6eb80a217;hpb=f18b7fc3361c4daac0ddd104af65a8eff8466fec;p=wimlib diff --git a/src/lzx_common.c b/src/lzx_common.c index 3cc6981b..0677e0a0 100644 --- a/src/lzx_common.c +++ b/src/lzx_common.c @@ -57,7 +57,7 @@ const u32 lzx_offset_slot_base[LZX_MAX_OFFSET_SLOTS + 1] = { /* Mapping: offset slot => how many extra bits must be read and added to the * corresponding offset slot base to decode the match offset. */ -const u8 lzx_extra_offset_bits[LZX_MAX_OFFSET_SLOTS + 1] = { +const u8 lzx_extra_offset_bits[LZX_MAX_OFFSET_SLOTS] = { 0 , 0 , 0 , 0 , 1 , 1 , 2 , 2 , 3 , 3 , 4 , 4 , 5 , 5 , 6 , @@ -68,7 +68,6 @@ const u8 lzx_extra_offset_bits[LZX_MAX_OFFSET_SLOTS + 1] = { 16, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, - 17 }; /* Round the specified buffer size up to the next valid LZX window size, and @@ -90,8 +89,10 @@ lzx_get_window_order(size_t max_bufsize) return max(order, LZX_MIN_WINDOW_ORDER); } +/* Given a valid LZX window order, return the number of symbols that will exist + * in the main Huffman code. */ unsigned -lzx_get_num_offset_slots(unsigned window_order) +lzx_get_num_main_syms(unsigned window_order) { /* Note: one would expect that the maximum match offset would be * 'window_size - LZX_MIN_MATCH_LEN', which would occur if the first two @@ -99,17 +100,13 @@ lzx_get_num_offset_slots(unsigned window_order) * disallows this case. This reduces the number of needed offset slots * by 1. */ u32 window_size = (u32)1 << window_order; - u32 max_offset = window_size - LZX_MIN_MATCH_LEN - 1; - return 1 + lzx_get_offset_slot(max_offset); -} + u32 max_adjusted_offset = (window_size - LZX_MIN_MATCH_LEN - 1) + + LZX_OFFSET_ADJUSTMENT; + unsigned num_offset_slots = 30; + while (max_adjusted_offset >= lzx_offset_slot_base[num_offset_slots]) + num_offset_slots++; -/* Given a valid LZX window order, return the number of symbols that will exist - * in the main Huffman code. */ -unsigned -lzx_get_num_main_syms(unsigned window_order) -{ - return LZX_NUM_CHARS + (lzx_get_num_offset_slots(window_order) * - LZX_NUM_LEN_HEADERS); + return LZX_NUM_CHARS + (num_offset_slots * LZX_NUM_LEN_HEADERS); } static void @@ -326,13 +323,13 @@ lzx_e8_filter(u8 *data, u32 size, void (*process_target)(void *, s32)) } void -lzx_do_e8_preprocessing(u8 *data, u32 size) +lzx_preprocess(u8 *data, u32 size) { lzx_e8_filter(data, size, do_translate_target); } void -lzx_undo_e8_preprocessing(u8 *data, u32 size) +lzx_postprocess(u8 *data, u32 size) { lzx_e8_filter(data, size, undo_translate_target); }