diff options
Diffstat (limited to 'src/liblzma/rangecoder')
-rw-r--r-- | src/liblzma/rangecoder/Makefile.inc | 21 | ||||
-rw-r--r-- | src/liblzma/rangecoder/price.h | 92 | ||||
-rw-r--r-- | src/liblzma/rangecoder/price_table.c | 22 | ||||
-rw-r--r-- | src/liblzma/rangecoder/price_tablegen.c | 87 | ||||
-rw-r--r-- | src/liblzma/rangecoder/range_common.h | 71 | ||||
-rw-r--r-- | src/liblzma/rangecoder/range_decoder.h | 185 | ||||
-rw-r--r-- | src/liblzma/rangecoder/range_encoder.h | 350 |
7 files changed, 828 insertions, 0 deletions
diff --git a/src/liblzma/rangecoder/Makefile.inc b/src/liblzma/rangecoder/Makefile.inc new file mode 100644 index 0000000..d8a597a --- /dev/null +++ b/src/liblzma/rangecoder/Makefile.inc @@ -0,0 +1,21 @@ +## +## Author: Lasse Collin +## +## This file has been put into the public domain. +## You can do whatever you want with this file. +## + +EXTRA_DIST += rangecoder/price_tablegen.c + +liblzma_la_SOURCES += rangecoder/range_common.h + +if COND_ENCODER_LZMA1 +liblzma_la_SOURCES += \ + rangecoder/range_encoder.h \ + rangecoder/price.h \ + rangecoder/price_table.c +endif + +if COND_DECODER_LZMA1 +liblzma_la_SOURCES += rangecoder/range_decoder.h +endif diff --git a/src/liblzma/rangecoder/price.h b/src/liblzma/rangecoder/price.h new file mode 100644 index 0000000..8ae02ca --- /dev/null +++ b/src/liblzma/rangecoder/price.h @@ -0,0 +1,92 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file price.h +/// \brief Probability price calculation +// +// Author: Igor Pavlov +// +// This file has been put into the public domain. +// You can do whatever you want with this file. +// +/////////////////////////////////////////////////////////////////////////////// + +#ifndef LZMA_PRICE_H +#define LZMA_PRICE_H + + +#define RC_MOVE_REDUCING_BITS 4 +#define RC_BIT_PRICE_SHIFT_BITS 4 +#define RC_PRICE_TABLE_SIZE (RC_BIT_MODEL_TOTAL >> RC_MOVE_REDUCING_BITS) + +#define RC_INFINITY_PRICE (UINT32_C(1) << 30) + + +/// Lookup table for the inline functions defined in this file. +extern const uint8_t lzma_rc_prices[RC_PRICE_TABLE_SIZE]; + + +static inline uint32_t +rc_bit_price(const probability prob, const uint32_t bit) +{ + return lzma_rc_prices[(prob ^ ((UINT32_C(0) - bit) + & (RC_BIT_MODEL_TOTAL - 1))) >> RC_MOVE_REDUCING_BITS]; +} + + +static inline uint32_t +rc_bit_0_price(const probability prob) +{ + return lzma_rc_prices[prob >> RC_MOVE_REDUCING_BITS]; +} + + +static inline uint32_t +rc_bit_1_price(const probability prob) +{ + return lzma_rc_prices[(prob ^ (RC_BIT_MODEL_TOTAL - 1)) + >> RC_MOVE_REDUCING_BITS]; +} + + +static inline uint32_t +rc_bittree_price(const probability *const probs, + const uint32_t bit_levels, uint32_t symbol) +{ + uint32_t price = 0; + symbol += UINT32_C(1) << bit_levels; + + do { + const uint32_t bit = symbol & 1; + symbol >>= 1; + price += rc_bit_price(probs[symbol], bit); + } while (symbol != 1); + + return price; +} + + +static inline uint32_t +rc_bittree_reverse_price(const probability *const probs, + uint32_t bit_levels, uint32_t symbol) +{ + uint32_t price = 0; + uint32_t model_index = 1; + + do { + const uint32_t bit = symbol & 1; + symbol >>= 1; + price += rc_bit_price(probs[model_index], bit); + model_index = (model_index << 1) + bit; + } while (--bit_levels != 0); + + return price; +} + + +static inline uint32_t +rc_direct_price(const uint32_t bits) +{ + return bits << RC_BIT_PRICE_SHIFT_BITS; +} + +#endif diff --git a/src/liblzma/rangecoder/price_table.c b/src/liblzma/rangecoder/price_table.c new file mode 100644 index 0000000..ac64bf6 --- /dev/null +++ b/src/liblzma/rangecoder/price_table.c @@ -0,0 +1,22 @@ +/* This file has been automatically generated by price_tablegen.c. */ + +#include "range_encoder.h" + +const uint8_t lzma_rc_prices[RC_PRICE_TABLE_SIZE] = { + 128, 103, 91, 84, 78, 73, 69, 66, + 63, 61, 58, 56, 54, 52, 51, 49, + 48, 46, 45, 44, 43, 42, 41, 40, + 39, 38, 37, 36, 35, 34, 34, 33, + 32, 31, 31, 30, 29, 29, 28, 28, + 27, 26, 26, 25, 25, 24, 24, 23, + 23, 22, 22, 22, 21, 21, 20, 20, + 19, 19, 19, 18, 18, 17, 17, 17, + 16, 16, 16, 15, 15, 15, 14, 14, + 14, 13, 13, 13, 12, 12, 12, 11, + 11, 11, 11, 10, 10, 10, 10, 9, + 9, 9, 9, 8, 8, 8, 8, 7, + 7, 7, 7, 6, 6, 6, 6, 5, + 5, 5, 5, 5, 4, 4, 4, 4, + 3, 3, 3, 3, 3, 2, 2, 2, + 2, 2, 2, 1, 1, 1, 1, 1 +}; diff --git a/src/liblzma/rangecoder/price_tablegen.c b/src/liblzma/rangecoder/price_tablegen.c new file mode 100644 index 0000000..bf08ce3 --- /dev/null +++ b/src/liblzma/rangecoder/price_tablegen.c @@ -0,0 +1,87 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file price_tablegen.c +/// \brief Probability price table generator +/// +/// Compiling: gcc -std=c99 -o price_tablegen price_tablegen.c +/// +// Authors: Igor Pavlov +// Lasse Collin +// +// This file has been put into the public domain. +// You can do whatever you want with this file. +// +/////////////////////////////////////////////////////////////////////////////// + +#include <inttypes.h> +#include <stdio.h> +#include "range_common.h" +#include "price.h" + + +static uint32_t rc_prices[RC_PRICE_TABLE_SIZE]; + + +static void +init_price_table(void) +{ + for (uint32_t i = (UINT32_C(1) << RC_MOVE_REDUCING_BITS) / 2; + i < RC_BIT_MODEL_TOTAL; + i += (UINT32_C(1) << RC_MOVE_REDUCING_BITS)) { + const uint32_t cycles_bits = RC_BIT_PRICE_SHIFT_BITS; + uint32_t w = i; + uint32_t bit_count = 0; + + for (uint32_t j = 0; j < cycles_bits; ++j) { + w *= w; + bit_count <<= 1; + + while (w >= (UINT32_C(1) << 16)) { + w >>= 1; + ++bit_count; + } + } + + rc_prices[i >> RC_MOVE_REDUCING_BITS] + = (RC_BIT_MODEL_TOTAL_BITS << cycles_bits) + - 15 - bit_count; + } + + return; +} + + +static void +print_price_table(void) +{ + printf("/* This file has been automatically generated by " + "price_tablegen.c. */\n\n" + "#include \"range_encoder.h\"\n\n" + "const uint8_t lzma_rc_prices[" + "RC_PRICE_TABLE_SIZE] = {"); + + const size_t array_size = sizeof(lzma_rc_prices) + / sizeof(lzma_rc_prices[0]); + for (size_t i = 0; i < array_size; ++i) { + if (i % 8 == 0) + printf("\n\t"); + + printf("%4" PRIu32, rc_prices[i]); + + if (i != array_size - 1) + printf(","); + } + + printf("\n};\n"); + + return; +} + + +int +main(void) +{ + init_price_table(); + print_price_table(); + return 0; +} diff --git a/src/liblzma/rangecoder/range_common.h b/src/liblzma/rangecoder/range_common.h new file mode 100644 index 0000000..2c74dc1 --- /dev/null +++ b/src/liblzma/rangecoder/range_common.h @@ -0,0 +1,71 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file range_common.h +/// \brief Common things for range encoder and decoder +/// +// Authors: Igor Pavlov +// Lasse Collin +// +// This file has been put into the public domain. +// You can do whatever you want with this file. +// +/////////////////////////////////////////////////////////////////////////////// + +#ifndef LZMA_RANGE_COMMON_H +#define LZMA_RANGE_COMMON_H + +#include "common.h" + + +/////////////// +// Constants // +/////////////// + +#define RC_SHIFT_BITS 8 +#define RC_TOP_BITS 24 +#define RC_TOP_VALUE (UINT32_C(1) << RC_TOP_BITS) +#define RC_BIT_MODEL_TOTAL_BITS 11 +#define RC_BIT_MODEL_TOTAL (UINT32_C(1) << RC_BIT_MODEL_TOTAL_BITS) +#define RC_MOVE_BITS 5 + + +//////////// +// Macros // +//////////// + +// Resets the probability so that both 0 and 1 have probability of 50 % +#define bit_reset(prob) \ + prob = RC_BIT_MODEL_TOTAL >> 1 + +// This does the same for a complete bit tree. +// (A tree represented as an array.) +#define bittree_reset(probs, bit_levels) \ + for (uint32_t bt_i = 0; bt_i < (1 << (bit_levels)); ++bt_i) \ + bit_reset((probs)[bt_i]) + + +////////////////////// +// Type definitions // +////////////////////// + +/// \brief Type of probabilities used with range coder +/// +/// This needs to be at least 12-bit integer, so uint16_t is a logical choice. +/// However, on some architecture and compiler combinations, a bigger type +/// may give better speed, because the probability variables are accessed +/// a lot. On the other hand, bigger probability type increases cache +/// footprint, since there are 2 to 14 thousand probability variables in +/// LZMA (assuming the limit of lc + lp <= 4; with lc + lp <= 12 there +/// would be about 1.5 million variables). +/// +/// With malicious files, the initialization speed of the LZMA decoder can +/// become important. In that case, smaller probability variables mean that +/// there is less bytes to write to RAM, which makes initialization faster. +/// With big probability type, the initialization can become so slow that it +/// can be a problem e.g. for email servers doing virus scanning. +/// +/// I will be sticking to uint16_t unless some specific architectures +/// are *much* faster (20-50 %) with uint32_t. +typedef uint16_t probability; + +#endif diff --git a/src/liblzma/rangecoder/range_decoder.h b/src/liblzma/rangecoder/range_decoder.h new file mode 100644 index 0000000..e0b051f --- /dev/null +++ b/src/liblzma/rangecoder/range_decoder.h @@ -0,0 +1,185 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file range_decoder.h +/// \brief Range Decoder +/// +// Authors: Igor Pavlov +// Lasse Collin +// +// This file has been put into the public domain. +// You can do whatever you want with this file. +// +/////////////////////////////////////////////////////////////////////////////// + +#ifndef LZMA_RANGE_DECODER_H +#define LZMA_RANGE_DECODER_H + +#include "range_common.h" + + +typedef struct { + uint32_t range; + uint32_t code; + uint32_t init_bytes_left; +} lzma_range_decoder; + + +/// Reads the first five bytes to initialize the range decoder. +static inline lzma_ret +rc_read_init(lzma_range_decoder *rc, const uint8_t *restrict in, + size_t *restrict in_pos, size_t in_size) +{ + while (rc->init_bytes_left > 0) { + if (*in_pos == in_size) + return LZMA_OK; + + // The first byte is always 0x00. It could have been omitted + // in LZMA2 but it wasn't, so one byte is wasted in every + // LZMA2 chunk. + if (rc->init_bytes_left == 5 && in[*in_pos] != 0x00) + return LZMA_DATA_ERROR; + + rc->code = (rc->code << 8) | in[*in_pos]; + ++*in_pos; + --rc->init_bytes_left; + } + + return LZMA_STREAM_END; +} + + +/// Makes local copies of range decoder and *in_pos variables. Doing this +/// improves speed significantly. The range decoder macros expect also +/// variables `in' and `in_size' to be defined. +#define rc_to_local(range_decoder, in_pos) \ + lzma_range_decoder rc = range_decoder; \ + size_t rc_in_pos = (in_pos); \ + uint32_t rc_bound + + +/// Stores the local copes back to the range decoder structure. +#define rc_from_local(range_decoder, in_pos) \ +do { \ + range_decoder = rc; \ + in_pos = rc_in_pos; \ +} while (0) + + +/// Resets the range decoder structure. +#define rc_reset(range_decoder) \ +do { \ + (range_decoder).range = UINT32_MAX; \ + (range_decoder).code = 0; \ + (range_decoder).init_bytes_left = 5; \ +} while (0) + + +/// When decoding has been properly finished, rc.code is always zero unless +/// the input stream is corrupt. So checking this can catch some corrupt +/// files especially if they don't have any other integrity check. +#define rc_is_finished(range_decoder) \ + ((range_decoder).code == 0) + + +/// Read the next input byte if needed. If more input is needed but there is +/// no more input available, "goto out" is used to jump out of the main +/// decoder loop. +#define rc_normalize(seq) \ +do { \ + if (rc.range < RC_TOP_VALUE) { \ + if (unlikely(rc_in_pos == in_size)) { \ + coder->sequence = seq; \ + goto out; \ + } \ + rc.range <<= RC_SHIFT_BITS; \ + rc.code = (rc.code << RC_SHIFT_BITS) | in[rc_in_pos++]; \ + } \ +} while (0) + + +/// Start decoding a bit. This must be used together with rc_update_0() +/// and rc_update_1(): +/// +/// rc_if_0(prob, seq) { +/// rc_update_0(prob); +/// // Do something +/// } else { +/// rc_update_1(prob); +/// // Do something else +/// } +/// +#define rc_if_0(prob, seq) \ + rc_normalize(seq); \ + rc_bound = (rc.range >> RC_BIT_MODEL_TOTAL_BITS) * (prob); \ + if (rc.code < rc_bound) + + +/// Update the range decoder state and the used probability variable to +/// match a decoded bit of 0. +#define rc_update_0(prob) \ +do { \ + rc.range = rc_bound; \ + prob += (RC_BIT_MODEL_TOTAL - (prob)) >> RC_MOVE_BITS; \ +} while (0) + + +/// Update the range decoder state and the used probability variable to +/// match a decoded bit of 1. +#define rc_update_1(prob) \ +do { \ + rc.range -= rc_bound; \ + rc.code -= rc_bound; \ + prob -= (prob) >> RC_MOVE_BITS; \ +} while (0) + + +/// Decodes one bit and runs action0 or action1 depending on the decoded bit. +/// This macro is used as the last step in bittree reverse decoders since +/// those don't use "symbol" for anything else than indexing the probability +/// arrays. +#define rc_bit_last(prob, action0, action1, seq) \ +do { \ + rc_if_0(prob, seq) { \ + rc_update_0(prob); \ + action0; \ + } else { \ + rc_update_1(prob); \ + action1; \ + } \ +} while (0) + + +/// Decodes one bit, updates "symbol", and runs action0 or action1 depending +/// on the decoded bit. +#define rc_bit(prob, action0, action1, seq) \ + rc_bit_last(prob, \ + symbol <<= 1; action0, \ + symbol = (symbol << 1) + 1; action1, \ + seq); + + +/// Like rc_bit() but add "case seq:" as a prefix. This makes the unrolled +/// loops more readable because the code isn't littered with "case" +/// statements. On the other hand this also makes it less readable, since +/// spotting the places where the decoder loop may be restarted is less +/// obvious. +#define rc_bit_case(prob, action0, action1, seq) \ + case seq: rc_bit(prob, action0, action1, seq) + + +/// Decode a bit without using a probability. +#define rc_direct(dest, seq) \ +do { \ + rc_normalize(seq); \ + rc.range >>= 1; \ + rc.code -= rc.range; \ + rc_bound = UINT32_C(0) - (rc.code >> 31); \ + rc.code += rc.range & rc_bound; \ + dest = (dest << 1) + (rc_bound + 1); \ +} while (0) + + +// NOTE: No macros are provided for bittree decoding. It seems to be simpler +// to just write them open in the code. + +#endif diff --git a/src/liblzma/rangecoder/range_encoder.h b/src/liblzma/rangecoder/range_encoder.h new file mode 100644 index 0000000..d794eab --- /dev/null +++ b/src/liblzma/rangecoder/range_encoder.h @@ -0,0 +1,350 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file range_encoder.h +/// \brief Range Encoder +/// +// Authors: Igor Pavlov +// Lasse Collin +// +// This file has been put into the public domain. +// You can do whatever you want with this file. +// +/////////////////////////////////////////////////////////////////////////////// + +#ifndef LZMA_RANGE_ENCODER_H +#define LZMA_RANGE_ENCODER_H + +#include "range_common.h" +#include "price.h" + + +/// Maximum number of symbols that can be put pending into lzma_range_encoder +/// structure between calls to lzma_rc_encode(). For LZMA, 48+5 is enough +/// (match with big distance and length followed by range encoder flush). +#define RC_SYMBOLS_MAX 53 + + +typedef struct { + uint64_t low; + uint64_t cache_size; + uint32_t range; + uint8_t cache; + + /// Number of bytes written out by rc_encode() -> rc_shift_low() + uint64_t out_total; + + /// Number of symbols in the tables + size_t count; + + /// rc_encode()'s position in the tables + size_t pos; + + /// Symbols to encode + enum { + RC_BIT_0, + RC_BIT_1, + RC_DIRECT_0, + RC_DIRECT_1, + RC_FLUSH, + } symbols[RC_SYMBOLS_MAX]; + + /// Probabilities associated with RC_BIT_0 or RC_BIT_1 + probability *probs[RC_SYMBOLS_MAX]; + +} lzma_range_encoder; + + +static inline void +rc_reset(lzma_range_encoder *rc) +{ + rc->low = 0; + rc->cache_size = 1; + rc->range = UINT32_MAX; + rc->cache = 0; + rc->out_total = 0; + rc->count = 0; + rc->pos = 0; +} + + +static inline void +rc_forget(lzma_range_encoder *rc) +{ + // This must not be called when rc_encode() is partially done. + assert(rc->pos == 0); + rc->count = 0; +} + + +static inline void +rc_bit(lzma_range_encoder *rc, probability *prob, uint32_t bit) +{ + rc->symbols[rc->count] = bit; + rc->probs[rc->count] = prob; + ++rc->count; +} + + +static inline void +rc_bittree(lzma_range_encoder *rc, probability *probs, + uint32_t bit_count, uint32_t symbol) +{ + uint32_t model_index = 1; + + do { + const uint32_t bit = (symbol >> --bit_count) & 1; + rc_bit(rc, &probs[model_index], bit); + model_index = (model_index << 1) + bit; + } while (bit_count != 0); +} + + +static inline void +rc_bittree_reverse(lzma_range_encoder *rc, probability *probs, + uint32_t bit_count, uint32_t symbol) +{ + uint32_t model_index = 1; + + do { + const uint32_t bit = symbol & 1; + symbol >>= 1; + rc_bit(rc, &probs[model_index], bit); + model_index = (model_index << 1) + bit; + } while (--bit_count != 0); +} + + +static inline void +rc_direct(lzma_range_encoder *rc, + uint32_t value, uint32_t bit_count) +{ + do { + rc->symbols[rc->count++] + = RC_DIRECT_0 + ((value >> --bit_count) & 1); + } while (bit_count != 0); +} + + +static inline void +rc_flush(lzma_range_encoder *rc) +{ + for (size_t i = 0; i < 5; ++i) + rc->symbols[rc->count++] = RC_FLUSH; +} + + +static inline bool +rc_shift_low(lzma_range_encoder *rc, + uint8_t *out, size_t *out_pos, size_t out_size) +{ + if ((uint32_t)(rc->low) < (uint32_t)(0xFF000000) + || (uint32_t)(rc->low >> 32) != 0) { + do { + if (*out_pos == out_size) + return true; + + out[*out_pos] = rc->cache + (uint8_t)(rc->low >> 32); + ++*out_pos; + ++rc->out_total; + rc->cache = 0xFF; + + } while (--rc->cache_size != 0); + + rc->cache = (rc->low >> 24) & 0xFF; + } + + ++rc->cache_size; + rc->low = (rc->low & 0x00FFFFFF) << RC_SHIFT_BITS; + + return false; +} + + +// NOTE: The last two arguments are uint64_t instead of size_t because in +// the dummy version these refer to the size of the whole range-encoded +// output stream, not just to the currently available output buffer space. +static inline bool +rc_shift_low_dummy(uint64_t *low, uint64_t *cache_size, uint8_t *cache, + uint64_t *out_pos, uint64_t out_size) +{ + if ((uint32_t)(*low) < (uint32_t)(0xFF000000) + || (uint32_t)(*low >> 32) != 0) { + do { + if (*out_pos == out_size) + return true; + + ++*out_pos; + *cache = 0xFF; + + } while (--*cache_size != 0); + + *cache = (*low >> 24) & 0xFF; + } + + ++*cache_size; + *low = (*low & 0x00FFFFFF) << RC_SHIFT_BITS; + + return false; +} + + +static inline bool +rc_encode(lzma_range_encoder *rc, + uint8_t *out, size_t *out_pos, size_t out_size) +{ + assert(rc->count <= RC_SYMBOLS_MAX); + + while (rc->pos < rc->count) { + // Normalize + if (rc->range < RC_TOP_VALUE) { + if (rc_shift_low(rc, out, out_pos, out_size)) + return true; + + rc->range <<= RC_SHIFT_BITS; + } + + // Encode a bit + switch (rc->symbols[rc->pos]) { + case RC_BIT_0: { + probability prob = *rc->probs[rc->pos]; + rc->range = (rc->range >> RC_BIT_MODEL_TOTAL_BITS) + * prob; + prob += (RC_BIT_MODEL_TOTAL - prob) >> RC_MOVE_BITS; + *rc->probs[rc->pos] = prob; + break; + } + + case RC_BIT_1: { + probability prob = *rc->probs[rc->pos]; + const uint32_t bound = prob * (rc->range + >> RC_BIT_MODEL_TOTAL_BITS); + rc->low += bound; + rc->range -= bound; + prob -= prob >> RC_MOVE_BITS; + *rc->probs[rc->pos] = prob; + break; + } + + case RC_DIRECT_0: + rc->range >>= 1; + break; + + case RC_DIRECT_1: + rc->range >>= 1; + rc->low += rc->range; + break; + + case RC_FLUSH: + // Prevent further normalizations. + rc->range = UINT32_MAX; + + // Flush the last five bytes (see rc_flush()). + do { + if (rc_shift_low(rc, out, out_pos, out_size)) + return true; + } while (++rc->pos < rc->count); + + // Reset the range encoder so we are ready to continue + // encoding if we weren't finishing the stream. + rc_reset(rc); + return false; + + default: + assert(0); + break; + } + + ++rc->pos; + } + + rc->count = 0; + rc->pos = 0; + + return false; +} + + +static inline bool +rc_encode_dummy(const lzma_range_encoder *rc, uint64_t out_limit) +{ + assert(rc->count <= RC_SYMBOLS_MAX); + + uint64_t low = rc->low; + uint64_t cache_size = rc->cache_size; + uint32_t range = rc->range; + uint8_t cache = rc->cache; + uint64_t out_pos = rc->out_total; + + size_t pos = rc->pos; + + while (true) { + // Normalize + if (range < RC_TOP_VALUE) { + if (rc_shift_low_dummy(&low, &cache_size, &cache, + &out_pos, out_limit)) + return true; + + range <<= RC_SHIFT_BITS; + } + + // This check is here because the normalization above must + // be done before flushing the last bytes. + if (pos == rc->count) + break; + + // Encode a bit + switch (rc->symbols[pos]) { + case RC_BIT_0: { + probability prob = *rc->probs[pos]; + range = (range >> RC_BIT_MODEL_TOTAL_BITS) + * prob; + break; + } + + case RC_BIT_1: { + probability prob = *rc->probs[pos]; + const uint32_t bound = prob * (range + >> RC_BIT_MODEL_TOTAL_BITS); + low += bound; + range -= bound; + break; + } + + case RC_DIRECT_0: + range >>= 1; + break; + + case RC_DIRECT_1: + range >>= 1; + low += range; + break; + + case RC_FLUSH: + default: + assert(0); + break; + } + + ++pos; + } + + // Flush the last bytes. This isn't in rc->symbols[] so we do + // it after the above loop to take into account the size of + // the flushing that will be done at the end of the stream. + for (pos = 0; pos < 5; ++pos) { + if (rc_shift_low_dummy(&low, &cache_size, + &cache, &out_pos, out_limit)) + return true; + } + + return false; +} + + +static inline uint64_t +rc_pending(const lzma_range_encoder *rc) +{ + return rc->cache_size + 5 - 1; +} + +#endif |