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flipperzero-firmware/lib/heatshrink/heatshrink_decoder.c
gornekich 827d99dde3
[FL-1922] Assets compression (#773) 
* lib: add heatshrink compress library
* canvas: new icons format
* scripts: add icons compression to assets generation script
* assets: update assets
* furi-hal: introduce furi-hal-compress
* canvas: rework icon drawing with furi-hal-compress
* lib: rework heatshrink lib for dynamic buffer allocation API
* furi-hal-compress: add encode and decode API
* furi-hal-compress: working decode
* furi-hal-compress: support f6 target
* scripts: format sources
* furi-hal-compress: fix incorrect encoder reset
* furi-hal: add compress initialization to f6 target

Co-authored-by: あく <alleteam@gmail.com>
2021-10-21 17:46:36 +03:00

365 lines
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#include <stdlib.h>
#include <string.h>
#include "heatshrink_decoder.h"
/* States for the polling state machine. */
typedef enum {
HSDS_TAG_BIT, /* tag bit */
HSDS_YIELD_LITERAL, /* ready to yield literal byte */
HSDS_BACKREF_INDEX_MSB, /* most significant byte of index */
HSDS_BACKREF_INDEX_LSB, /* least significant byte of index */
HSDS_BACKREF_COUNT_MSB, /* most significant byte of count */
HSDS_BACKREF_COUNT_LSB, /* least significant byte of count */
HSDS_YIELD_BACKREF, /* ready to yield back-reference */
} HSD_state;
#if HEATSHRINK_DEBUGGING_LOGS
#include <stdio.h>
#include <ctype.h>
#include <assert.h>
#define LOG(...) fprintf(stderr, __VA_ARGS__)
#define ASSERT(X) assert(X)
static const char *state_names[] = {
"tag_bit",
"yield_literal",
"backref_index_msb",
"backref_index_lsb",
"backref_count_msb",
"backref_count_lsb",
"yield_backref",
};
#else
#define LOG(...) /* no-op */
#define ASSERT(X) /* no-op */
#endif
typedef struct {
uint8_t *buf; /* output buffer */
size_t buf_size; /* buffer size */
size_t *output_size; /* bytes pushed to buffer, so far */
} output_info;
#define NO_BITS ((uint16_t)-1)
/* Forward references. */
static uint16_t get_bits(heatshrink_decoder *hsd, uint8_t count);
static void push_byte(heatshrink_decoder *hsd, output_info *oi, uint8_t byte);
#if HEATSHRINK_DYNAMIC_ALLOC
heatshrink_decoder *heatshrink_decoder_alloc(uint8_t* buffer,
uint16_t input_buffer_size,
uint8_t window_sz2,
uint8_t lookahead_sz2) {
if ((window_sz2 < HEATSHRINK_MIN_WINDOW_BITS) ||
(window_sz2 > HEATSHRINK_MAX_WINDOW_BITS) ||
(input_buffer_size == 0) ||
(lookahead_sz2 < HEATSHRINK_MIN_LOOKAHEAD_BITS) ||
(lookahead_sz2 >= window_sz2)) {
return NULL;
}
size_t sz = sizeof(heatshrink_decoder);
heatshrink_decoder *hsd = HEATSHRINK_MALLOC(sz);
if (hsd == NULL) { return NULL; }
hsd->input_buffer_size = input_buffer_size;
hsd->window_sz2 = window_sz2;
hsd->lookahead_sz2 = lookahead_sz2;
hsd->buffers = buffer;
heatshrink_decoder_reset(hsd);
LOG("-- allocated decoder with buffer size of %zu (%zu + %u + %u)\n",
sz, sizeof(heatshrink_decoder), (1 << window_sz2), input_buffer_size);
return hsd;
}
void heatshrink_decoder_free(heatshrink_decoder *hsd) {
size_t sz = sizeof(heatshrink_decoder);
HEATSHRINK_FREE(hsd, sz);
(void)sz; /* may not be used by free */
}
#endif
void heatshrink_decoder_reset(heatshrink_decoder *hsd) {
hsd->state = HSDS_TAG_BIT;
hsd->input_size = 0;
hsd->input_index = 0;
hsd->bit_index = 0x00;
hsd->current_byte = 0x00;
hsd->output_count = 0;
hsd->output_index = 0;
hsd->head_index = 0;
}
/* Copy SIZE bytes into the decoder's input buffer, if it will fit. */
HSD_sink_res heatshrink_decoder_sink(heatshrink_decoder *hsd,
uint8_t *in_buf, size_t size, size_t *input_size) {
if ((hsd == NULL) || (in_buf == NULL) || (input_size == NULL)) {
return HSDR_SINK_ERROR_NULL;
}
size_t rem = HEATSHRINK_DECODER_INPUT_BUFFER_SIZE(hsd) - hsd->input_size;
if (rem == 0) {
*input_size = 0;
return HSDR_SINK_FULL;
}
size = rem < size ? rem : size;
LOG("-- sinking %zd bytes\n", size);
/* copy into input buffer (at head of buffers) */
memcpy(&hsd->buffers[hsd->input_size], in_buf, size);
hsd->input_size += size;
*input_size = size;
return HSDR_SINK_OK;
}
/*****************
* Decompression *
*****************/
#define BACKREF_COUNT_BITS(HSD) (HEATSHRINK_DECODER_LOOKAHEAD_BITS(HSD))
#define BACKREF_INDEX_BITS(HSD) (HEATSHRINK_DECODER_WINDOW_BITS(HSD))
// States
static HSD_state st_tag_bit(heatshrink_decoder *hsd);
static HSD_state st_yield_literal(heatshrink_decoder *hsd,
output_info *oi);
static HSD_state st_backref_index_msb(heatshrink_decoder *hsd);
static HSD_state st_backref_index_lsb(heatshrink_decoder *hsd);
static HSD_state st_backref_count_msb(heatshrink_decoder *hsd);
static HSD_state st_backref_count_lsb(heatshrink_decoder *hsd);
static HSD_state st_yield_backref(heatshrink_decoder *hsd,
output_info *oi);
HSD_poll_res heatshrink_decoder_poll(heatshrink_decoder *hsd,
uint8_t *out_buf, size_t out_buf_size, size_t *output_size) {
if ((hsd == NULL) || (out_buf == NULL) || (output_size == NULL)) {
return HSDR_POLL_ERROR_NULL;
}
*output_size = 0;
output_info oi;
oi.buf = out_buf;
oi.buf_size = out_buf_size;
oi.output_size = output_size;
while (1) {
LOG("-- poll, state is %d (%s), input_size %d\n",
hsd->state, state_names[hsd->state], hsd->input_size);
uint8_t in_state = hsd->state;
switch (in_state) {
case HSDS_TAG_BIT:
hsd->state = st_tag_bit(hsd);
break;
case HSDS_YIELD_LITERAL:
hsd->state = st_yield_literal(hsd, &oi);
break;
case HSDS_BACKREF_INDEX_MSB:
hsd->state = st_backref_index_msb(hsd);
break;
case HSDS_BACKREF_INDEX_LSB:
hsd->state = st_backref_index_lsb(hsd);
break;
case HSDS_BACKREF_COUNT_MSB:
hsd->state = st_backref_count_msb(hsd);
break;
case HSDS_BACKREF_COUNT_LSB:
hsd->state = st_backref_count_lsb(hsd);
break;
case HSDS_YIELD_BACKREF:
hsd->state = st_yield_backref(hsd, &oi);
break;
default:
return HSDR_POLL_ERROR_UNKNOWN;
}
/* If the current state cannot advance, check if input or output
* buffer are exhausted. */
if (hsd->state == in_state) {
if (*output_size == out_buf_size) { return HSDR_POLL_MORE; }
return HSDR_POLL_EMPTY;
}
}
}
static HSD_state st_tag_bit(heatshrink_decoder *hsd) {
uint32_t bits = get_bits(hsd, 1); // get tag bit
if (bits == NO_BITS) {
return HSDS_TAG_BIT;
} else if (bits) {
return HSDS_YIELD_LITERAL;
} else if (HEATSHRINK_DECODER_WINDOW_BITS(hsd) > 8) {
return HSDS_BACKREF_INDEX_MSB;
} else {
hsd->output_index = 0;
return HSDS_BACKREF_INDEX_LSB;
}
}
static HSD_state st_yield_literal(heatshrink_decoder *hsd,
output_info *oi) {
/* Emit a repeated section from the window buffer, and add it (again)
* to the window buffer. (Note that the repetition can include
* itself.)*/
if (*oi->output_size < oi->buf_size) {
uint16_t byte = get_bits(hsd, 8);
if (byte == NO_BITS) { return HSDS_YIELD_LITERAL; } /* out of input */
uint8_t *buf = &hsd->buffers[HEATSHRINK_DECODER_INPUT_BUFFER_SIZE(hsd)];
uint16_t mask = (1 << HEATSHRINK_DECODER_WINDOW_BITS(hsd)) - 1;
uint8_t c = byte & 0xFF;
LOG("-- emitting literal byte 0x%02x ('%c')\n", c, isprint(c) ? c : '.');
buf[hsd->head_index++ & mask] = c;
push_byte(hsd, oi, c);
return HSDS_TAG_BIT;
} else {
return HSDS_YIELD_LITERAL;
}
}
static HSD_state st_backref_index_msb(heatshrink_decoder *hsd) {
uint8_t bit_ct = BACKREF_INDEX_BITS(hsd);
ASSERT(bit_ct > 8);
uint16_t bits = get_bits(hsd, bit_ct - 8);
LOG("-- backref index (msb), got 0x%04x (+1)\n", bits);
if (bits == NO_BITS) { return HSDS_BACKREF_INDEX_MSB; }
hsd->output_index = bits << 8;
return HSDS_BACKREF_INDEX_LSB;
}
static HSD_state st_backref_index_lsb(heatshrink_decoder *hsd) {
uint8_t bit_ct = BACKREF_INDEX_BITS(hsd);
uint16_t bits = get_bits(hsd, bit_ct < 8 ? bit_ct : 8);
LOG("-- backref index (lsb), got 0x%04x (+1)\n", bits);
if (bits == NO_BITS) { return HSDS_BACKREF_INDEX_LSB; }
hsd->output_index |= bits;
hsd->output_index++;
uint8_t br_bit_ct = BACKREF_COUNT_BITS(hsd);
hsd->output_count = 0;
return (br_bit_ct > 8) ? HSDS_BACKREF_COUNT_MSB : HSDS_BACKREF_COUNT_LSB;
}
static HSD_state st_backref_count_msb(heatshrink_decoder *hsd) {
uint8_t br_bit_ct = BACKREF_COUNT_BITS(hsd);
ASSERT(br_bit_ct > 8);
uint16_t bits = get_bits(hsd, br_bit_ct - 8);
LOG("-- backref count (msb), got 0x%04x (+1)\n", bits);
if (bits == NO_BITS) { return HSDS_BACKREF_COUNT_MSB; }
hsd->output_count = bits << 8;
return HSDS_BACKREF_COUNT_LSB;
}
static HSD_state st_backref_count_lsb(heatshrink_decoder *hsd) {
uint8_t br_bit_ct = BACKREF_COUNT_BITS(hsd);
uint16_t bits = get_bits(hsd, br_bit_ct < 8 ? br_bit_ct : 8);
LOG("-- backref count (lsb), got 0x%04x (+1)\n", bits);
if (bits == NO_BITS) { return HSDS_BACKREF_COUNT_LSB; }
hsd->output_count |= bits;
hsd->output_count++;
return HSDS_YIELD_BACKREF;
}
static HSD_state st_yield_backref(heatshrink_decoder *hsd,
output_info *oi) {
size_t count = oi->buf_size - *oi->output_size;
if (count > 0) {
size_t i = 0;
if (hsd->output_count < count) count = hsd->output_count;
uint8_t *buf = &hsd->buffers[HEATSHRINK_DECODER_INPUT_BUFFER_SIZE(hsd)];
uint16_t mask = (1 << HEATSHRINK_DECODER_WINDOW_BITS(hsd)) - 1;
uint16_t neg_offset = hsd->output_index;
LOG("-- emitting %zu bytes from -%u bytes back\n", count, neg_offset);
ASSERT(neg_offset <= mask + 1);
ASSERT(count <= (size_t)(1 << BACKREF_COUNT_BITS(hsd)));
for (i=0; i<count; i++) {
uint8_t c = buf[(hsd->head_index - neg_offset) & mask];
push_byte(hsd, oi, c);
buf[hsd->head_index & mask] = c;
hsd->head_index++;
LOG(" -- ++ 0x%02x\n", c);
}
hsd->output_count -= count;
if (hsd->output_count == 0) { return HSDS_TAG_BIT; }
}
return HSDS_YIELD_BACKREF;
}
/* Get the next COUNT bits from the input buffer, saving incremental progress.
* Returns NO_BITS on end of input, or if more than 15 bits are requested. */
static uint16_t get_bits(heatshrink_decoder *hsd, uint8_t count) {
uint16_t accumulator = 0;
int i = 0;
if (count > 15) { return NO_BITS; }
LOG("-- popping %u bit(s)\n", count);
/* If we aren't able to get COUNT bits, suspend immediately, because we
* don't track how many bits of COUNT we've accumulated before suspend. */
if (hsd->input_size == 0) {
if (hsd->bit_index < (1 << (count - 1))) { return NO_BITS; }
}
for (i = 0; i < count; i++) {
if (hsd->bit_index == 0x00) {
if (hsd->input_size == 0) {
LOG(" -- out of bits, suspending w/ accumulator of %u (0x%02x)\n",
accumulator, accumulator);
return NO_BITS;
}
hsd->current_byte = hsd->buffers[hsd->input_index++];
LOG(" -- pulled byte 0x%02x\n", hsd->current_byte);
if (hsd->input_index == hsd->input_size) {
hsd->input_index = 0; /* input is exhausted */
hsd->input_size = 0;
}
hsd->bit_index = 0x80;
}
accumulator <<= 1;
if (hsd->current_byte & hsd->bit_index) {
accumulator |= 0x01;
if (0) {
LOG(" -- got 1, accumulator 0x%04x, bit_index 0x%02x\n",
accumulator, hsd->bit_index);
}
} else {
if (0) {
LOG(" -- got 0, accumulator 0x%04x, bit_index 0x%02x\n",
accumulator, hsd->bit_index);
}
}
hsd->bit_index >>= 1;
}
if (count > 1) { LOG(" -- accumulated %08x\n", accumulator); }
return accumulator;
}
HSD_finish_res heatshrink_decoder_finish(heatshrink_decoder *hsd) {
if (hsd == NULL) { return HSDR_FINISH_ERROR_NULL; }
switch (hsd->state) {
case HSDS_TAG_BIT:
return hsd->input_size == 0 ? HSDR_FINISH_DONE : HSDR_FINISH_MORE;
/* If we want to finish with no input, but are in these states, it's
* because the 0-bit padding to the last byte looks like a backref
* marker bit followed by all 0s for index and count bits. */
case HSDS_BACKREF_INDEX_LSB:
case HSDS_BACKREF_INDEX_MSB:
case HSDS_BACKREF_COUNT_LSB:
case HSDS_BACKREF_COUNT_MSB:
return hsd->input_size == 0 ? HSDR_FINISH_DONE : HSDR_FINISH_MORE;
/* If the output stream is padded with 0xFFs (possibly due to being in
* flash memory), also explicitly check the input size rather than
* uselessly returning MORE but yielding 0 bytes when polling. */
case HSDS_YIELD_LITERAL:
return hsd->input_size == 0 ? HSDR_FINISH_DONE : HSDR_FINISH_MORE;
default:
return HSDR_FINISH_MORE;
}
}
static void push_byte(heatshrink_decoder *hsd, output_info *oi, uint8_t byte) {
LOG(" -- pushing byte: 0x%02x ('%c')\n", byte, isprint(byte) ? byte : '.');
oi->buf[(*oi->output_size)++] = byte;
(void)hsd;
}
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