HSE_sink_res heatshrink_encoder_sink(heatshrink_encoder *hse,
uint8_t *in_buf, size_t size, size_t *input_size) {
if ((hse == NULL) || (in_buf == NULL) || (input_size == NULL)) {
return HSER_SINK_ERROR_NULL;
}
/* Sinking more content after saying the content is done, tsk tsk */
if (is_finishing(hse)) { return HSER_SINK_ERROR_MISUSE; }
/* Sinking more content before processing is done */
if (hse->state != HSES_NOT_FULL) { return HSER_SINK_ERROR_MISUSE; }
uint16_t write_offset = get_input_offset(hse) + hse->input_size;
uint16_t ibs = get_input_buffer_size(hse);
uint16_t rem = ibs - hse->input_size;
uint16_t cp_sz = rem < size ? rem : size;
memcpy(&hse->buffer[write_offset], in_buf, cp_sz);
*input_size = cp_sz;
hse->input_size += cp_sz;
LOG("-- sunk %u bytes (of %zu) into encoder at %d, input buffer now has %u\n",
cp_sz, size, write_offset, hse->input_size);
if (cp_sz == rem) {
LOG("-- internal buffer is now full\n");
hse->state = HSES_FILLED;
}
return HSER_SINK_OK;
}
static HSE_state ICACHE_FLASH_ATTR st_step_search(heatshrink_encoder *hse) {
uint16_t window_length = get_input_buffer_size(hse);
uint16_t lookahead_sz = get_lookahead_size(hse);
uint16_t msi = hse->match_scan_index;
LOG("## step_search, scan @ +%d (%d/%d), input size %d\n",
msi, hse->input_size + msi, 2*window_length, hse->input_size);
bool fin = is_finishing(hse);
if (msi >= hse->input_size - (fin ? 0 : lookahead_sz)) {
/* Current search buffer is exhausted, copy it into the
* backlog and await more input. */
LOG("-- end of search @ %d, saving backlog\n", msi);
return HSES_SAVE_BACKLOG;
}
uint16_t input_offset = get_input_offset(hse);
uint16_t end = input_offset + msi;
uint16_t start = 0;
if (backlog_is_filled(hse)) { /* last WINDOW_LENGTH bytes */
start = end - window_length + 1;
} else if (backlog_is_partial(hse)) { /* clamp to available data */
start = end - window_length + 1;
if (start < lookahead_sz) { start = lookahead_sz; }
} else { /* only scan available input */
start = input_offset;
}
uint16_t max_possible = lookahead_sz;
if (hse->input_size - msi < lookahead_sz) {
max_possible = hse->input_size - msi;
}
uint16_t match_length = 0;
uint16_t match_pos = find_longest_match(hse,
start, end, max_possible, &match_length);
if (match_pos == MATCH_NOT_FOUND) {
LOG("ss Match not found\n");
hse->match_scan_index++;
hse->flags |= FLAG_HAS_LITERAL;
hse->match_length = 0;
return HSES_YIELD_TAG_BIT;
} else {
LOG("ss Found match of %d bytes at %d\n", match_length, match_pos);
hse->match_pos = match_pos;
hse->match_length = match_length;
ASSERT(match_pos < 1 << hse->window_sz2 /*window_length*/);
return HSES_YIELD_TAG_BIT;
}
}
static HSE_state ICACHE_FLASH_ATTR st_save_backlog(heatshrink_encoder *hse) {
if (is_finishing(hse)) {
/* copy remaining literal (if necessary) */
if (has_literal(hse)) {
hse->flags |= FLAG_ON_FINAL_LITERAL;
return HSES_YIELD_TAG_BIT;
} else {
return HSES_FLUSH_BITS;
}
} else {
LOG("-- saving backlog\n");
save_backlog(hse);
return HSES_NOT_FULL;
}
}
static HSE_state st_step_search(heatshrink_encoder *hse) {
uint16_t window_length = get_input_buffer_size(hse);
uint16_t lookahead_sz = get_lookahead_size(hse);
uint16_t msi = hse->match_scan_index;
LOG("## step_search, scan @ +%d (%d/%d), input size %d\n",
msi, hse->input_size + msi, 2*window_length, hse->input_size);
bool fin = is_finishing(hse);
if (msi > hse->input_size - (fin ? 1 : lookahead_sz)) {
/* Current search buffer is exhausted, copy it into the
* backlog and await more input. */
LOG("-- end of search @ %d\n", msi);
return fin ? HSES_FLUSH_BITS : HSES_SAVE_BACKLOG;
}
uint16_t input_offset = get_input_offset(hse);
uint16_t end = input_offset + msi;
uint16_t start = end - window_length;
uint16_t max_possible = lookahead_sz;
if (hse->input_size - msi < lookahead_sz) {
max_possible = hse->input_size - msi;
}
uint16_t match_length = 0;
uint16_t match_pos = find_longest_match(hse,
start, end, max_possible, &match_length);
if (match_pos == MATCH_NOT_FOUND) {
LOG("ss Match not found\n");
hse->match_scan_index++;
hse->match_length = 0;
return HSES_YIELD_TAG_BIT;
} else {
LOG("ss Found match of %d bytes at %d\n", match_length, match_pos);
hse->match_pos = match_pos;
hse->match_length = match_length;
ASSERT(match_pos < 1 << HEATSHRINK_ENCODER_WINDOW_BITS(hse) /*window_length*/);
return HSES_YIELD_TAG_BIT;
}
}
