Imported to git.

1 files changed, 317 insertions, 0 deletions

diff --git a/src/liblzma/rangecoder/range_encoder.h b/src/liblzma/rangecoder/range_encoder.h
new file mode 100644
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+++ b/src/liblzma/rangecoder/range_encoder.h
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+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       range_encoder.h
+/// \brief      Range Encoder
+//
+//  Copyright (C) 1999-2006 Igor Pavlov
+//  Copyright (C) 2007 Lasse Collin
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+//  Lesser General Public License for more details.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef LZMA_RANGE_ENCODER_H
+#define LZMA_RANGE_ENCODER_H
+
+#include "range_common.h"
+
+
+// Allow #including this file even if RC_TEMP_BUFFER_SIZE isn't defined.
+#ifdef RC_BUFFER_SIZE
+typedef struct {
+	uint64_t low;
+	uint32_t range;
+	uint32_t cache_size;
+	uint8_t cache;
+	uint8_t buffer[RC_BUFFER_SIZE];
+	size_t buffer_size;
+} lzma_range_encoder;
+#endif
+
+
+/// Makes local copies of range encoder variables.
+#define rc_to_local(rc) \
+	uint64_t rc_low = (rc).low; \
+	uint32_t rc_range = (rc).range; \
+	uint32_t rc_cache_size = (rc).cache_size; \
+	uint8_t rc_cache = (rc).cache; \
+	uint8_t *rc_buffer = (rc).buffer; \
+	size_t rc_buffer_size = (rc).buffer_size
+
+/// Stores the local copes back to the range encoder structure.
+#define rc_from_local(rc) \
+do { \
+	(rc).low = rc_low; \
+	(rc).range = rc_range; \
+	(rc).cache_size = rc_cache_size; \
+	(rc).cache = rc_cache; \
+	(rc).buffer_size = rc_buffer_size; \
+} while (0)
+
+/// Resets the range encoder structure.
+#define rc_reset(rc) \
+do { \
+	(rc).low = 0; \
+	(rc).range = 0xFFFFFFFF; \
+	(rc).cache_size = 1; \
+	(rc).cache = 0; \
+	(rc).buffer_size = 0; \
+} while (0)
+
+
+//////////////////
+// Bit encoding //
+//////////////////
+
+// These macros expect that the following variables are defined:
+//  - uint64_t  rc_low;
+//  - uint32_t  rc_range;
+//  - uint8_t   rc_cache;
+//  - uint32_t  rc_cache_size;
+//  - uint8_t   *out;
+//  - size_t    out_pos_local;  // Local copy of *out_pos
+//  - size_t    size_out;
+
+
+// Combined from NRangeCoder::CEncoder::Encode()
+// and NRangeCoder::CEncoder::UpdateModel().
+#define bit_encode(prob, symbol) \
+do { \
+	probability rc_prob = prob; \
+	const uint32_t rc_bound \
+			= (rc_range >> BIT_MODEL_TOTAL_BITS) * rc_prob; \
+	if ((symbol) == 0) { \
+		rc_range = rc_bound; \
+		rc_prob += (BIT_MODEL_TOTAL - rc_prob) >> MOVE_BITS; \
+	} else { \
+		rc_low += rc_bound; \
+		rc_range -= rc_bound; \
+		rc_prob -= rc_prob >> MOVE_BITS; \
+	} \
+	prob = rc_prob; \
+	rc_normalize(); \
+} while (0)
+
+
+// Optimized version of bit_encode(prob, 0)
+#define bit_encode_0(prob) \
+do { \
+	probability rc_prob = prob; \
+	rc_range = (rc_range >> BIT_MODEL_TOTAL_BITS) * rc_prob; \
+	rc_prob += (BIT_MODEL_TOTAL - rc_prob) >> MOVE_BITS; \
+	prob = rc_prob; \
+	rc_normalize(); \
+} while (0)
+
+
+// Optimized version of bit_encode(prob, 1)
+#define bit_encode_1(prob) \
+do { \
+	probability rc_prob = prob; \
+	const uint32_t rc_bound = (rc_range >> BIT_MODEL_TOTAL_BITS) \
+			* rc_prob; \
+	rc_low += rc_bound; \
+	rc_range -= rc_bound; \
+	rc_prob -= rc_prob >> MOVE_BITS; \
+	prob = rc_prob; \
+	rc_normalize(); \
+} while (0)
+
+
+///////////////////////
+// Bit tree encoding //
+///////////////////////
+
+#define bittree_encode(probs, bit_levels, symbol) \
+do { \
+	uint32_t model_index = 1; \
+	for (int32_t bit_index = bit_levels - 1; \
+			bit_index >= 0; --bit_index) { \
+		const uint32_t bit = ((symbol) >> bit_index) & 1; \
+		bit_encode((probs)[model_index], bit); \
+		model_index = (model_index << 1) | bit; \
+	} \
+} while (0)
+
+
+#define bittree_reverse_encode(probs, bit_levels, symbol) \
+do { \
+	uint32_t model_index = 1; \
+	for (uint32_t bit_index = 0; bit_index < bit_levels; ++bit_index) { \
+		const uint32_t bit = ((symbol) >> bit_index) & 1; \
+		bit_encode((probs)[model_index], bit); \
+		model_index = (model_index << 1) | bit; \
+	} \
+} while (0)
+
+
+/////////////////
+// Direct bits //
+/////////////////
+
+#define rc_encode_direct_bits(value, num_total_bits) \
+do { \
+	for (int32_t rc_i = (num_total_bits) - 1; rc_i >= 0; --rc_i) { \
+		rc_range >>= 1; \
+		if ((((value) >> rc_i) & 1) == 1) \
+			rc_low += rc_range; \
+		rc_normalize(); \
+	} \
+} while (0)
+
+
+//////////////////
+// Buffer "I/O" //
+//////////////////
+
+// Calls rc_shift_low() to write out a byte if needed.
+#define rc_normalize() \
+do { \
+	if (rc_range < TOP_VALUE) { \
+		rc_range <<= SHIFT_BITS; \
+		rc_shift_low(); \
+	} \
+} while (0)
+
+
+// Flushes all the pending output.
+#define rc_flush() \
+	for (int32_t rc_i = 0; rc_i < 5; ++rc_i) \
+		rc_shift_low()
+
+
+// Writes the compressed data to next_out.
+// TODO: Notation change?
+//       (uint32_t)(0xFF000000)  =>  ((uint32_t)(0xFF) << TOP_BITS)
+// TODO: Another notation change?
+//       rc_low = (uint32_t)(rc_low) << SHIFT_BITS;
+//       =>
+//       rc_low &= TOP_VALUE - 1;
+//       rc_low <<= SHIFT_BITS;
+#define rc_shift_low() \
+do { \
+	if ((uint32_t)(rc_low) < (uint32_t)(0xFF000000) \
+			|| (uint32_t)(rc_low >> 32) != 0) { \
+		uint8_t rc_temp = rc_cache; \
+		do { \
+			rc_write_byte(rc_temp + (uint8_t)(rc_low >> 32)); \
+			rc_temp = 0xFF; \
+		} while(--rc_cache_size != 0); \
+		rc_cache = (uint8_t)((uint32_t)(rc_low) >> 24); \
+	} \
+	++rc_cache_size; \
+	rc_low = (uint32_t)(rc_low) << SHIFT_BITS; \
+} while (0)
+
+
+// Write one byte of compressed data to *next_out. Updates out_pos_local.
+// If out_pos_local == out_size, the byte is appended to rc_buffer.
+#define rc_write_byte(b) \
+do { \
+	if (out_pos_local == out_size) { \
+		rc_buffer[rc_buffer_size++] = (uint8_t)(b); \
+		assert(rc_buffer_size < RC_BUFFER_SIZE); \
+	} else { \
+		assert(rc_buffer_size == 0); \
+		out[out_pos_local++] = (uint8_t)(b); \
+	} \
+} while (0)
+
+
+//////////////////
+// Price macros //
+//////////////////
+
+// These macros expect that the following variables are defined:
+//  - uint32_t lzma_rc_prob_prices;
+
+#define bit_get_price(prob, symbol) \
+	lzma_rc_prob_prices[((((prob) - (symbol)) ^ (-(symbol))) \
+			& (BIT_MODEL_TOTAL - 1)) >> MOVE_REDUCING_BITS]
+
+
+#define bit_get_price_0(prob) \
+	lzma_rc_prob_prices[(prob) >> MOVE_REDUCING_BITS]
+
+
+#define bit_get_price_1(prob) \
+	lzma_rc_prob_prices[(BIT_MODEL_TOTAL - (prob)) >> MOVE_REDUCING_BITS]
+
+
+// Adds price to price_target. TODO Optimize/Cleanup?
+#define bittree_get_price(price_target, probs, bit_levels, symbol) \
+do { \
+	uint32_t bittree_symbol = (symbol) | (UINT32_C(1) << bit_levels); \
+	while (bittree_symbol != 1) { \
+		price_target += bit_get_price((probs)[bittree_symbol >> 1], \
+				bittree_symbol & 1); \
+		bittree_symbol >>= 1; \
+	} \
+} while (0)
+
+
+// Adds price to price_target.
+#define bittree_reverse_get_price(price_target, probs, bit_levels, symbol) \
+do { \
+	uint32_t model_index = 1; \
+	for (uint32_t bit_index = 0; bit_index < bit_levels; ++bit_index) { \
+		const uint32_t bit = ((symbol) >> bit_index) & 1; \
+		price_target += bit_get_price((probs)[model_index], bit); \
+		model_index = (model_index << 1) | bit; \
+	} \
+} while (0)
+
+
+//////////////////////
+// Global variables //
+//////////////////////
+
+// Probability prices used by *_get_price() macros. This is initialized
+// by lzma_rc_init() and is not modified later.
+extern uint32_t lzma_rc_prob_prices[BIT_MODEL_TOTAL >> MOVE_REDUCING_BITS];
+
+
+///////////////
+// Functions //
+///////////////
+
+/// Initializes lzma_rc_prob_prices[]. This needs to be called only once.
+extern void lzma_rc_init(void);
+
+
+#ifdef RC_BUFFER_SIZE
+/// Flushes data from rc->temp[] to out[] as much as possible. If everything
+/// cannot be flushed, returns true; false otherwise.
+static inline bool
+rc_flush_buffer(lzma_range_encoder *rc,
+		uint8_t *out, size_t *out_pos, size_t out_size)
+{
+	if (rc->buffer_size > 0) {
+		const size_t out_avail = out_size - *out_pos;
+		if (rc->buffer_size > out_avail) {
+			memcpy(out + *out_pos, rc->buffer, out_avail);
+			*out_pos += out_avail;
+			rc->buffer_size -= out_avail;
+			memmove(rc->buffer, rc->buffer + out_avail,
+					rc->buffer_size);
+			return true;
+		}
+
+		memcpy(out + *out_pos, rc->buffer, rc->buffer_size);
+		*out_pos += rc->buffer_size;
+		rc->buffer_size = 0;
+	}
+
+	return false;
+}
+#endif
+
+#endif