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/* Copyright 2025 Google Inc. All Rights Reserved.
Distributed under MIT license.
See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
*/
#include "prefix.h"
#include "../common/platform.h" /* IWYU pragma: keep */
#include "../common/static_init.h"
#if (BROTLI_STATIC_INIT != BROTLI_STATIC_INIT_NONE)
#include "../common/constants.h"
#endif
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif
#if (BROTLI_STATIC_INIT == BROTLI_STATIC_INIT_NONE)
/* Embed kCmdLut. */
#include "prefix_inc.h"
#else
BROTLI_COLD BROTLI_BOOL BrotliDecoderInitCmdLut(CmdLutElement* items) {
static const uint8_t kInsertLengthExtraBits[24] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01, 0x02, 0x02, 0x03, 0x03,
0x04, 0x04, 0x05, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0C, 0x0E, 0x18};
static const uint8_t kCopyLengthExtraBits[24] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01, 0x02, 0x02,
0x03, 0x03, 0x04, 0x04, 0x05, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x18};
static const uint8_t kCellPos[11] = {0, 1, 0, 1, 8, 9, 2, 16, 10, 17, 18};
uint16_t insert_length_offsets[24];
uint16_t copy_length_offsets[24];
insert_length_offsets[0] = 0;
copy_length_offsets[0] = 2;
for (size_t i = 0; i < 23; ++i) {
insert_length_offsets[i + 1] =
insert_length_offsets[i] + (uint16_t)(1u << kInsertLengthExtraBits[i]);
copy_length_offsets[i + 1] =
copy_length_offsets[i] + (uint16_t)(1u << kCopyLengthExtraBits[i]);
}
for (size_t symbol = 0; symbol < BROTLI_NUM_COMMAND_SYMBOLS; ++symbol) {
CmdLutElement* item = items + symbol;
const size_t cell_idx = symbol >> 6;
const size_t cell_pos = kCellPos[cell_idx];
const size_t copy_code = ((cell_pos << 3) & 0x18) + (symbol & 0x7);
const uint16_t copy_len_offset = copy_length_offsets[copy_code];
const size_t insert_code = (cell_pos & 0x18) + ((symbol >> 3) & 0x7);
item->copy_len_extra_bits = kCopyLengthExtraBits[copy_code];
item->context = (copy_len_offset > 4) ? 3 : ((uint8_t)copy_len_offset - 2);
item->copy_len_offset = copy_len_offset;
item->distance_code = (cell_idx >= 2) ? -1 : 0;
item->insert_len_extra_bits = kInsertLengthExtraBits[insert_code];
item->insert_len_offset = insert_length_offsets[insert_code];
}
return BROTLI_TRUE;
}
BROTLI_MODEL("small")
CmdLutElement kCmdLut[BROTLI_NUM_COMMAND_SYMBOLS];
#endif /* BROTLI_STATIC_INIT */
#if defined(__cplusplus) || defined(c_plusplus)
} /* extern "C" */
#endif
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