From 31a918533ce2b5a2796a671b14c82b9f2c1dd5df Mon Sep 17 00:00:00 2001
From: Daniel Friesel <derf@finalrewind.org>
Date: Mon, 1 Feb 2021 21:23:58 +0100
Subject: [PATCH] update deflate library
---
Makefile | 4 ++
src/app/deflatetest/Makefile.inc | 4 ++
src/lib/inflate.cc | 92 ++++++++++++++++++++++++++++++--
3 files changed, 97 insertions(+), 3 deletions(-)
diff --git a/Makefile b/Makefile
index e7ce2cc..369d26c 100644
--- a/Makefile
+++ b/Makefile
@@ -266,6 +266,10 @@ ifdef CONFIG_lib_inflate_checksum
COMMON_FLAGS += -DDEFLATE_CHECKSUM
endif
+ifdef CONFIG_lib_inflate_lut
+ COMMON_FLAGS += -DDEFLATE_WITH_LUT
+endif
+
# Configure drivers (TODO: Kconfig)
ifneq (${i2c_freq}, )
diff --git a/src/app/deflatetest/Makefile.inc b/src/app/deflatetest/Makefile.inc
index d1275be..1a60b75 100644
--- a/src/app/deflatetest/Makefile.inc
+++ b/src/app/deflatetest/Makefile.inc
@@ -19,3 +19,7 @@ endif
ifdef deflate_checksum
override CONFIG_lib_inflate_checksum = y
endif
+
+ifdef deflate_with_lut
+ override CONFIG_lib_inflate_lut = y
+endif
diff --git a/src/lib/inflate.cc b/src/lib/inflate.cc
index 8f46979..854ddb2 100644
--- a/src/lib/inflate.cc
+++ b/src/lib/inflate.cc
@@ -92,6 +92,11 @@ uint8_t deflate_hc_lengths[19];
*/
uint8_t deflate_lld_lengths[318];
+#ifdef DEFLATE_WITH_LUT
+uint16_t deflate_ll_codes[288];
+uint16_t deflate_d_codes[30];
+#endif
+
/*
* Bit length counts and next code entries for Literal/Length alphabet.
* Combined with the code lengths in deflate_lld_lengths, these make up the
@@ -159,8 +164,14 @@ static uint16_t deflate_get_bits(uint8_t num_bits)
return ret & deflate_bitmask(num_bits);
}
+#ifdef DEFLATE_WITH_LUT
+static void deflate_build_alphabet(uint8_t * lengths, uint16_t size,
+ uint8_t * bl_count, uint16_t * next_code,
+ uint16_t * codes)
+#else
static void deflate_build_alphabet(uint8_t * lengths, uint16_t size,
uint8_t * bl_count, uint16_t * next_code)
+#endif
{
uint16_t i;
uint16_t code = 0;
@@ -178,12 +189,28 @@ static void deflate_build_alphabet(uint8_t * lengths, uint16_t size,
}
}
- for (i = 1; i < max_len + 1; i++) {
+ for (i = 1; i <= max_len; i++) {
code = (code + bl_count[i - 1]) << 1;
next_code[i] = code;
}
+
+#ifdef DEFLATE_WITH_LUT
+ uint8_t j = 0;
+ code = 0;
+ for (j = 1; j <= max_len; j++) {
+ for (i = 0; i < size; i++) {
+ if (lengths[i] == j) {
+ codes[code++] = i;
+ }
+ }
+ }
+#endif
}
+#ifdef DEFLATE_WITH_LUT
+static uint16_t deflate_huff(uint16_t * codes,
+ uint8_t * bl_count, uint16_t * next_code)
+#else
/*
* This function trades speed for low memory requirements. Instead of building
* an actual huffman tree (at a cost of about 650 Bytes of RAM), we iterate
@@ -192,8 +219,12 @@ static void deflate_build_alphabet(uint8_t * lengths, uint16_t size,
*/
static uint16_t deflate_huff(uint8_t * lengths, uint16_t size,
uint8_t * bl_count, uint16_t * next_code)
+#endif
{
uint16_t next_word = deflate_get_word();
+#ifdef DEFLATE_WITH_LUT
+ uint16_t code = 0;
+#endif
for (uint8_t num_bits = 1; num_bits < 16; num_bits++) {
uint16_t next_bits = deflate_rev_word(next_word, num_bits);
if (bl_count[num_bits] && next_bits >= next_code[num_bits]
@@ -203,9 +234,11 @@ static uint16_t deflate_huff(uint8_t * lengths, uint16_t size,
deflate_input_now++;
deflate_bit_offset -= 8;
}
+#ifdef DEFLATE_WITH_LUT
+ return codes[code + (next_bits - next_code[num_bits])];
+#else
uint8_t len_pos = next_bits;
uint8_t cur_pos = next_code[num_bits];
- // This is slow, but memory-efficient
for (uint16_t i = 0; i < size; i++) {
if (lengths[i] == num_bits) {
if (cur_pos == len_pos) {
@@ -214,20 +247,35 @@ static uint16_t deflate_huff(uint8_t * lengths, uint16_t size,
cur_pos++;
}
}
+#endif
+ } else {
+#ifdef DEFLATE_WITH_LUT
+ code += bl_count[num_bits];
+#endif
}
}
return 65535;
}
+#ifdef DEFLATE_WITH_LUT
+static int8_t deflate_huffman(uint16_t * ll_codes, uint16_t * d_codes)
+#else
static int8_t deflate_huffman(uint8_t * ll_lengths, uint16_t ll_size,
uint8_t * d_lengths, uint8_t d_size)
+#endif
{
uint16_t code;
uint16_t dcode;
while (1) {
+#ifdef DEFLATE_WITH_LUT
+ code =
+ deflate_huff(ll_codes, deflate_bl_count_ll,
+ deflate_next_code_ll);
+#else
code =
deflate_huff(ll_lengths, ll_size, deflate_bl_count_ll,
deflate_next_code_ll);
+#endif
if (code < 256) {
if (deflate_output_now == deflate_output_end) {
return DEFLATE_ERR_OUTPUT_LENGTH;
@@ -244,10 +292,17 @@ static int8_t deflate_huffman(uint8_t * ll_lengths, uint16_t ll_size,
if (extra_bits) {
len_val += deflate_get_bits(extra_bits);
}
+#ifdef DEFLATE_WITH_LUT
+ dcode =
+ deflate_huff(d_codes,
+ deflate_bl_count_d,
+ deflate_next_code_d);
+#else
dcode =
deflate_huff(d_lengths, d_size,
deflate_bl_count_d,
deflate_next_code_d);
+#endif
uint16_t dist_val = deflate_distance_offsets[dcode];
extra_bits = deflate_distance_bits[dcode];
if (extra_bits) {
@@ -313,12 +368,21 @@ static int8_t deflate_static_huffman()
deflate_lld_lengths[i] = 5;
}
+#ifdef DEFLATE_WITH_LUT
+ deflate_build_alphabet(deflate_lld_lengths, 288, deflate_bl_count_ll,
+ deflate_next_code_ll, deflate_ll_codes);
+ deflate_build_alphabet(deflate_lld_lengths + 288, 29,
+ deflate_bl_count_d, deflate_next_code_d,
+ deflate_d_codes);
+ return deflate_huffman(deflate_ll_codes, deflate_d_codes);
+#else
deflate_build_alphabet(deflate_lld_lengths, 288, deflate_bl_count_ll,
deflate_next_code_ll);
deflate_build_alphabet(deflate_lld_lengths + 288, 29,
deflate_bl_count_d, deflate_next_code_d);
return deflate_huffman(deflate_lld_lengths, 288,
deflate_lld_lengths + 288, 29);
+#endif
}
static int8_t deflate_dynamic_huffman()
@@ -336,16 +400,29 @@ static int8_t deflate_dynamic_huffman()
deflate_hc_lengths[deflate_hclen_index[i]] = 0;
}
+#ifdef DEFLATE_WITH_LUT
+ deflate_build_alphabet(deflate_hc_lengths,
+ sizeof(deflate_hc_lengths),
+ deflate_bl_count_ll, deflate_next_code_ll,
+ deflate_ll_codes);
+#else
deflate_build_alphabet(deflate_hc_lengths,
sizeof(deflate_hc_lengths),
deflate_bl_count_ll, deflate_next_code_ll);
+#endif
uint16_t items_processed = 0;
while (items_processed < hlit + hdist) {
+#ifdef DEFLATE_WITH_LUT
+ uint8_t code = deflate_huff(deflate_ll_codes,
+ deflate_bl_count_ll,
+ deflate_next_code_ll);
+#else
uint8_t code =
deflate_huff(deflate_hc_lengths, sizeof(deflate_hc_lengths),
deflate_bl_count_ll,
deflate_next_code_ll);
+#endif
if (code == 16) {
uint8_t copy_count = 3 + deflate_get_bits(2);
for (uint8_t i = 0; i < copy_count; i++) {
@@ -371,13 +448,22 @@ static int8_t deflate_dynamic_huffman()
}
}
+#ifdef DEFLATE_WITH_LUT
+ deflate_build_alphabet(deflate_lld_lengths, hlit,
+ deflate_bl_count_ll, deflate_next_code_ll,
+ deflate_ll_codes);
+ deflate_build_alphabet(deflate_lld_lengths + hlit, hdist,
+ deflate_bl_count_d, deflate_next_code_d,
+ deflate_d_codes);
+ return deflate_huffman(deflate_ll_codes, deflate_d_codes);
+#else
deflate_build_alphabet(deflate_lld_lengths, hlit,
deflate_bl_count_ll, deflate_next_code_ll);
deflate_build_alphabet(deflate_lld_lengths + hlit, hdist,
deflate_bl_count_d, deflate_next_code_d);
-
return deflate_huffman(deflate_lld_lengths, hlit,
deflate_lld_lengths + hlit, hdist);
+#endif
}
int16_t inflate(unsigned char *input_buf, uint16_t input_len,
--
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