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authorRob Landley2006-06-20 22:38:00 +0000
committerRob Landley2006-06-20 22:38:00 +0000
commitb13fee4cbb98a20ae761da46b02b58cb47f289ab (patch)
treef7909ad87f1bc06d9d02c6589ae646a013d35558 /archival/libunarchive/rangecoder.h
parent5483de1cb71b9cac095e4f6b65196b5390c06560 (diff)
downloadbusybox-b13fee4cbb98a20ae761da46b02b58cb47f289ab.zip
busybox-b13fee4cbb98a20ae761da46b02b58cb47f289ab.tar.gz
Since rangecoder is just a bunch of C functions, move it into the one user
(decompress_unlzma.c). Also a slight #include cleanup, and I've been meaning to put #include <unistd.h> into libbb.h since it's so darn common...
Diffstat (limited to 'archival/libunarchive/rangecoder.h')
-rw-r--r--archival/libunarchive/rangecoder.h147
1 files changed, 0 insertions, 147 deletions
diff --git a/archival/libunarchive/rangecoder.h b/archival/libunarchive/rangecoder.h
deleted file mode 100644
index b806eeb..0000000
--- a/archival/libunarchive/rangecoder.h
+++ /dev/null
@@ -1,147 +0,0 @@
-
-#include "libbb.h"
-
-#ifdef CONFIG_FEATURE_LZMA_FAST
-# define speed_inline ATTRIBUTE_ALWAYS_INLINE
-#else
-# define speed_inline
-#endif
-
-
-typedef struct {
- int fd;
- uint8_t *ptr;
- uint8_t *buffer;
- uint8_t *buffer_end;
- int buffer_size;
- uint32_t code;
- uint32_t range;
- uint32_t bound;
-} rc_t;
-
-
-#define RC_TOP_BITS 24
-#define RC_MOVE_BITS 5
-#define RC_MODEL_TOTAL_BITS 11
-
-
-/* Called twice: once at startup and once in rc_normalize() */
-static void rc_read(rc_t * rc)
-{
- rc->buffer_size = read(rc->fd, rc->buffer, rc->buffer_size);
- if (rc->buffer_size <= 0)
- bb_error_msg_and_die("unexpected EOF");
- rc->ptr = rc->buffer;
- rc->buffer_end = rc->buffer + rc->buffer_size;
-}
-
-/* Called once */
-static void rc_init(rc_t * rc, int fd, int buffer_size)
-{
- int i;
-
- rc->fd = fd;
- rc->buffer = xmalloc(buffer_size);
- rc->buffer_size = buffer_size;
- rc->buffer_end = rc->buffer + rc->buffer_size;
- rc->ptr = rc->buffer_end;
-
- rc->code = 0;
- rc->range = 0xFFFFFFFF;
- for (i = 0; i < 5; i++) {
- if (rc->ptr >= rc->buffer_end)
- rc_read(rc);
- rc->code = (rc->code << 8) | *rc->ptr++;
- }
-}
-
-/* Called once. TODO: bb_maybe_free() */
-static ATTRIBUTE_ALWAYS_INLINE void rc_free(rc_t * rc)
-{
- if (ENABLE_FEATURE_CLEAN_UP)
- free(rc->buffer);
-}
-
-/* Called twice, but one callsite is in speed_inline'd rc_is_bit_0_helper() */
-static void rc_do_normalize(rc_t * rc)
-{
- if (rc->ptr >= rc->buffer_end)
- rc_read(rc);
- rc->range <<= 8;
- rc->code = (rc->code << 8) | *rc->ptr++;
-}
-static ATTRIBUTE_ALWAYS_INLINE void rc_normalize(rc_t * rc)
-{
- if (rc->range < (1 << RC_TOP_BITS)) {
- rc_do_normalize(rc);
- }
-}
-
-/* Called 9 times */
-/* Why rc_is_bit_0_helper exists?
- * Because we want to always expose (rc->code < rc->bound) to optimizer
- */
-static speed_inline uint32_t rc_is_bit_0_helper(rc_t * rc, uint16_t * p)
-{
- rc_normalize(rc);
- rc->bound = *p * (rc->range >> RC_MODEL_TOTAL_BITS);
- return rc->bound;
-}
-static ATTRIBUTE_ALWAYS_INLINE int rc_is_bit_0(rc_t * rc, uint16_t * p)
-{
- uint32_t t = rc_is_bit_0_helper(rc, p);
- return rc->code < t;
-}
-
-/* Called ~10 times, but very small, thus inlined */
-static speed_inline void rc_update_bit_0(rc_t * rc, uint16_t * p)
-{
- rc->range = rc->bound;
- *p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS;
-}
-static speed_inline void rc_update_bit_1(rc_t * rc, uint16_t * p)
-{
- rc->range -= rc->bound;
- rc->code -= rc->bound;
- *p -= *p >> RC_MOVE_BITS;
-}
-
-/* Called 4 times in unlzma loop */
-static int rc_get_bit(rc_t * rc, uint16_t * p, int *symbol)
-{
- if (rc_is_bit_0(rc, p)) {
- rc_update_bit_0(rc, p);
- *symbol *= 2;
- return 0;
- } else {
- rc_update_bit_1(rc, p);
- *symbol = *symbol * 2 + 1;
- return 1;
- }
-}
-
-/* Called once */
-static ATTRIBUTE_ALWAYS_INLINE int rc_direct_bit(rc_t * rc)
-{
- rc_normalize(rc);
- rc->range >>= 1;
- if (rc->code >= rc->range) {
- rc->code -= rc->range;
- return 1;
- }
- return 0;
-}
-
-/* Called twice */
-static speed_inline void
-rc_bit_tree_decode(rc_t * rc, uint16_t * p, int num_levels, int *symbol)
-{
- int i = num_levels;
-
- *symbol = 1;
- while (i--)
- rc_get_bit(rc, p + *symbol, symbol);
- *symbol -= 1 << num_levels;
-}
-
-/* vi:set ts=4: */