/
Deflate.c
1241 lines (1049 loc) · 42.3 KB
/
Deflate.c
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#include "Deflate.h"
#include "Logger.h"
#include "Funcs.h"
#include "Platform.h"
#include "Stream.h"
#include "Errors.h"
#include "Utils.h"
#define Header_ReadU8(value) if ((res = s->ReadU8(s, &value))) return res;
/*########################################################################################################################*
*-------------------------------------------------------GZip header-------------------------------------------------------*
*#########################################################################################################################*/
enum GzipState {
GZIP_STATE_HEADER1, GZIP_STATE_HEADER2, GZIP_STATE_COMPRESSIONMETHOD, GZIP_STATE_FLAGS,
GZIP_STATE_LASTMODIFIED, GZIP_STATE_COMPRESSIONFLAGS, GZIP_STATE_OPERATINGSYSTEM,
GZIP_STATE_HEADERCHECKSUM, GZIP_STATE_FILENAME, GZIP_STATE_COMMENT, GZIP_STATE_DONE
};
void GZipHeader_Init(struct GZipHeader* header) {
header->State = GZIP_STATE_HEADER1;
header->Done = false;
header->Flags = 0;
header->PartsRead = 0;
}
ReturnCode GZipHeader_Read(struct Stream* s, struct GZipHeader* header) {
uint8_t tmp;
ReturnCode res;
switch (header->State) {
case GZIP_STATE_HEADER1:
Header_ReadU8(tmp);
if (tmp != 0x1F) return GZIP_ERR_HEADER1;
header->State++;
case GZIP_STATE_HEADER2:
Header_ReadU8(tmp);
if (tmp != 0x8B) return GZIP_ERR_HEADER2;
header->State++;
case GZIP_STATE_COMPRESSIONMETHOD:
Header_ReadU8(tmp);
if (tmp != 0x08) return GZIP_ERR_METHOD;
header->State++;
case GZIP_STATE_FLAGS:
Header_ReadU8(tmp);
if (header->Flags & 0x04) return GZIP_ERR_FLAGS;
header->State++;
case GZIP_STATE_LASTMODIFIED:
for (; header->PartsRead < 4; header->PartsRead++) {
Header_ReadU8(tmp);
}
header->State++;
header->PartsRead = 0;
case GZIP_STATE_COMPRESSIONFLAGS:
Header_ReadU8(tmp);
header->State++;
case GZIP_STATE_OPERATINGSYSTEM:
Header_ReadU8(tmp);
header->State++;
case GZIP_STATE_FILENAME:
if (header->Flags & 0x08) {
for (; ;) {
Header_ReadU8(tmp);
if (tmp == '\0') break;
}
}
header->State++;
case GZIP_STATE_COMMENT:
if (header->Flags & 0x10) {
for (; ;) {
Header_ReadU8(tmp);
if (tmp == '\0') break;
}
}
header->State++;
case GZIP_STATE_HEADERCHECKSUM:
if (header->Flags & 0x02) {
for (; header->PartsRead < 2; header->PartsRead++) {
Header_ReadU8(tmp);
}
}
header->State++;
header->PartsRead = 0;
header->Done = true;
}
return 0;
}
/*########################################################################################################################*
*-------------------------------------------------------ZLib header-------------------------------------------------------*
*#########################################################################################################################*/
enum ZlibState { ZLIB_STATE_COMPRESSIONMETHOD, ZLIB_STATE_FLAGS, ZLIB_STATE_DONE };
void ZLibHeader_Init(struct ZLibHeader* header) {
header->State = ZLIB_STATE_COMPRESSIONMETHOD;
header->Done = false;
}
ReturnCode ZLibHeader_Read(struct Stream* s, struct ZLibHeader* header) {
uint8_t tmp;
ReturnCode res;
switch (header->State) {
case ZLIB_STATE_COMPRESSIONMETHOD:
Header_ReadU8(tmp);
if ((tmp & 0x0F) != 0x08) return ZLIB_ERR_METHOD;
if ((tmp >> 4) > 7) return ZLIB_ERR_WINDOW_SIZE;
/* 2^(size + 8) must be < 32768 for LZ77 window */
header->State++;
case ZLIB_STATE_FLAGS:
Header_ReadU8(tmp);
if (tmp & 0x20) return ZLIB_ERR_FLAGS;
header->State++;
header->Done = true;
}
return 0;
}
/*########################################################################################################################*
*--------------------------------------------------Inflate (decompress)---------------------------------------------------*
*#########################################################################################################################*/
enum INFLATE_STATE_ {
INFLATE_STATE_HEADER, INFLATE_STATE_UNCOMPRESSED_HEADER,
INFLATE_STATE_UNCOMPRESSED_DATA, INFLATE_STATE_DYNAMIC_HEADER,
INFLATE_STATE_DYNAMIC_CODELENS, INFLATE_STATE_DYNAMIC_LITSDISTS,
INFLATE_STATE_DYNAMIC_LITSDISTSREPEAT, INFLATE_STATE_COMPRESSED_LIT,
INFLATE_STATE_COMPRESSED_LITREPEAT, INFLATE_STATE_COMPRESSED_DIST,
INFLATE_STATE_COMPRESSED_DISTREPEAT, INFLATE_STATE_COMPRESSED_DATA,
INFLATE_STATE_FASTCOMPRESSED, INFLATE_STATE_DONE
};
/* Insert next byte into the bit buffer */
#define Inflate_GetByte(state) state->AvailIn--; state->Bits |= (uint32_t)(*state->NextIn++) << state->NumBits; state->NumBits += 8;
/* Retrieves bits from the bit buffer */
#define Inflate_PeekBits(state, bits) (state->Bits & ((1UL << (bits)) - 1UL))
/* Consumes/eats up bits from the bit buffer */
#define Inflate_ConsumeBits(state, bits) state->Bits >>= (bits); state->NumBits -= (bits);
/* Aligns bit buffer to be on a byte boundary */
#define Inflate_AlignBits(state) uint32_t alignSkip = state->NumBits & 7; Inflate_ConsumeBits(state, alignSkip);
/* Ensures there are 'bitsCount' bits, or returns if not */
#define Inflate_EnsureBits(state, bitsCount) while (state->NumBits < bitsCount) { if (!state->AvailIn) return; Inflate_GetByte(state); }
/* Ensures there are 'bitsCount' bits */
#define Inflate_UNSAFE_EnsureBits(state, bitsCount) while (state->NumBits < bitsCount) { Inflate_GetByte(state); }
/* Peeks then consumes given bits */
#define Inflate_ReadBits(state, bitsCount) Inflate_PeekBits(state, bitsCount); Inflate_ConsumeBits(state, bitsCount);
/* Goes to the next state, after having read data of a block */
#define Inflate_NextBlockState(state) (state->LastBlock ? INFLATE_STATE_DONE : INFLATE_STATE_HEADER)
/* Goes to the next state, after having finished reading a compressed entry */
#define Inflate_NextCompressState(state) ((state->AvailIn >= INFLATE_FASTINF_IN && state->AvailOut >= INFLATE_FASTINF_OUT) ? INFLATE_STATE_FASTCOMPRESSED : INFLATE_STATE_COMPRESSED_LIT)
/* The maximum amount of bytes that can be output is 258 */
#define INFLATE_FASTINF_OUT 258
/* The most input bytes required for huffman codes and extra data is 16 + 5 + 16 + 13 bits. Add 3 extra bytes to account for putting data into the bit buffer. */
#define INFLATE_FASTINF_IN 10
static uint32_t Huffman_ReverseBits(uint32_t n, uint8_t bits) {
n = ((n & 0xAAAA) >> 1) | ((n & 0x5555) << 1);
n = ((n & 0xCCCC) >> 2) | ((n & 0x3333) << 2);
n = ((n & 0xF0F0) >> 4) | ((n & 0x0F0F) << 4);
n = ((n & 0xFF00) >> 8) | ((n & 0x00FF) << 8);
return n >> (16 - bits);
}
/* Builds a huffman tree, based on input lengths of each codeword */
static void Huffman_Build(struct HuffmanTable* table, const uint8_t* bitLens, int count) {
int bl_count[INFLATE_MAX_BITS], bl_offsets[INFLATE_MAX_BITS];
int code, offset, value;
int i, j;
/* Initialise 'zero bit length' codewords */
table->FirstCodewords[0] = 0;
table->FirstOffsets[0] = 0;
table->EndCodewords[0] = 0;
/* Count number of codewords assigned to each bit length */
for (i = 0; i < INFLATE_MAX_BITS; i++) bl_count[i] = 0;
for (i = 0; i < count; i++) {
bl_count[bitLens[i]]++;
}
/* Ensure huffman tree actually makes sense */
bl_count[0] = 0;
for (i = 1; i < INFLATE_MAX_BITS; i++) {
if (bl_count[i] > (1 << i)) {
Logger_Abort("Too many huffman codes for bit length");
}
}
/* Compute the codewords for the huffman tree.
* Codewords are ordered, so consider this example tree:
* 2 of length 2, 3 of length 3, 1 of length 4
* Codewords produced would be: 00,01 100,101,110, 1110
*/
code = 0; offset = 0;
for (i = 1; i < INFLATE_MAX_BITS; i++) {
code = (code + bl_count[i - 1]) << 1;
bl_offsets[i] = offset;
table->FirstCodewords[i] = code;
table->FirstOffsets[i] = offset;
offset += bl_count[i];
/* Last codeword is actually: code + (bl_count[i] - 1)
* However, when decoding we peform < against this value though, so need to add 1 here.
* This way, don't need to special case bit lengths with 0 codewords when decoding.
*/
if (bl_count[i]) {
table->EndCodewords[i] = code + bl_count[i];
} else {
table->EndCodewords[i] = 0;
}
}
/* Assigns values to each codeword.
* Note that although codewords are ordered, values may not be.
* Some values may also not be assigned to any codeword.
*/
value = 0;
Mem_Set(table->Fast, UInt8_MaxValue, sizeof(table->Fast));
for (i = 0; i < count; i++, value++) {
int len = bitLens[i];
if (!len) continue;
table->Values[bl_offsets[len]] = value;
/* Compute the accelerated lookup table values for this codeword.
* For example, assume len = 4 and codeword = 0100
* - Shift it left to be 0100_00000
* - Then, for all the indices from 0100_00000 to 0100_11111,
* - bit reverse index, as huffman codes are read backwards
* - set fast value to specify a 'value' value, and to skip 'len' bits
*/
if (len <= INFLATE_FAST_BITS) {
int16_t packed = (int16_t)((len << INFLATE_FAST_BITS) | value);
int codeword = table->FirstCodewords[len] + (bl_offsets[len] - table->FirstOffsets[len]);
codeword <<= (INFLATE_FAST_BITS - len);
for (j = 0; j < 1 << (INFLATE_FAST_BITS - len); j++, codeword++) {
int index = Huffman_ReverseBits(codeword, INFLATE_FAST_BITS);
table->Fast[index] = packed;
}
}
bl_offsets[len]++;
}
}
/* Attempts to read the next huffman encoded value from the bitstream, using given table */
/* Returns -1 if there are insufficient bits to read the value */
static int Huffman_Decode(struct InflateState* state, struct HuffmanTable* table) {
uint32_t i, j, codeword;
int packed, bits, offset;
/* Buffer as many bits as possible */
while (state->NumBits <= INFLATE_MAX_BITS) {
if (!state->AvailIn) break;
Inflate_GetByte(state);
}
/* Try fast accelerated table lookup */
if (state->NumBits >= INFLATE_FAST_BITS) {
packed = table->Fast[Inflate_PeekBits(state, INFLATE_FAST_BITS)];
if (packed >= 0) {
bits = packed >> INFLATE_FAST_BITS;
Inflate_ConsumeBits(state, bits);
return packed & 0x1FF;
}
}
/* Slow, bit by bit lookup */
codeword = 0;
for (i = 1, j = 0; i < INFLATE_MAX_BITS; i++, j++) {
if (state->NumBits < i) return -1;
codeword = (codeword << 1) | ((state->Bits >> j) & 1);
if (codeword < table->EndCodewords[i]) {
offset = table->FirstOffsets[i] + (codeword - table->FirstCodewords[i]);
Inflate_ConsumeBits(state, i);
return table->Values[offset];
}
}
Logger_Abort("DEFLATE - Invalid huffman code");
return -1;
}
/* Inline the common <= 9 bits case */
#define Huffman_Unsafe_Decode(state, table, result) \
{\
Inflate_UNSAFE_EnsureBits(state, INFLATE_MAX_BITS);\
packed = table.Fast[Inflate_PeekBits(state, INFLATE_FAST_BITS)];\
if (packed >= 0) {\
consumedBits = packed >> INFLATE_FAST_BITS;\
Inflate_ConsumeBits(state, consumedBits);\
result = packed & 0x1FF;\
} else {\
result = Huffman_Unsafe_Decode_Slow(state, &table);\
}\
}
static int Huffman_Unsafe_Decode_Slow(struct InflateState* state, struct HuffmanTable* table) {
uint32_t i, j, codeword;
int offset;
/* Slow, bit by bit lookup. Need to reverse order for huffman. */
codeword = Inflate_PeekBits(state, INFLATE_FAST_BITS);
codeword = Huffman_ReverseBits(codeword, INFLATE_FAST_BITS);
for (i = INFLATE_FAST_BITS + 1, j = INFLATE_FAST_BITS; i < INFLATE_MAX_BITS; i++, j++) {
codeword = (codeword << 1) | ((state->Bits >> j) & 1);
if (codeword < table->EndCodewords[i]) {
offset = table->FirstOffsets[i] + (codeword - table->FirstCodewords[i]);
Inflate_ConsumeBits(state, i);
return table->Values[offset];
}
}
Logger_Abort("DEFLATE - Invalid huffman code");
return -1;
}
void Inflate_Init(struct InflateState* state, struct Stream* source) {
state->State = INFLATE_STATE_HEADER;
state->LastBlock = false;
state->Bits = 0;
state->NumBits = 0;
state->NextIn = state->Input;
state->AvailIn = 0;
state->Output = NULL;
state->AvailOut = 0;
state->Source = source;
state->WindowIndex = 0;
}
const static uint8_t fixed_lits[INFLATE_MAX_LITS] = {
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, 7,7,7,7,7,7,7,7,8,8,8,8,8,8,8,8
};
const static uint8_t fixed_dists[INFLATE_MAX_DISTS] = {
5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5, 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5
};
static uint16_t len_base[31] = {
3,4,5,6,7,8,9,10,11,13,
15,17,19,23,27,31,35,43,51,59,
67,83,99,115,131,163,195,227,258,0,0
};
static uint8_t len_bits[31] = {
0,0,0,0,0,0,0,0,1,1,
1,1,2,2,2,2,3,3,3,3,
4,4,4,4,5,5,5,5,0,0,0
};
static uint16_t dist_base[32] = {
1,2,3,4,5,7,9,13,17,25,
33,49,65,97,129,193,257,385,513,769,
1025,1537,2049,3073,4097,6145,8193,12289,16385,24577,0,0
};
static uint8_t dist_bits[32] = {
0,0,0,0,1,1,2,2,3,3,
4,4,5,5,6,6,7,7,8,8,
9,9,10,10,11,11,12,12,13,13,0,0
};
static uint8_t codelens_order[INFLATE_MAX_CODELENS] = {
16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15
};
static void Inflate_InflateFast(struct InflateState* state) {
/* huffman variables */
uint32_t lit, len, dist;
uint32_t bits, lenIdx, distIdx;
int packed, consumedBits;
/* window variables */
uint8_t* window;
uint32_t i, curIdx, startIdx;
uint32_t copyStart, copyLen, partLen;
window = state->Window;
curIdx = state->WindowIndex;
copyStart = state->WindowIndex;
copyLen = 0;
#define INFLATE_FAST_COPY_MAX (INFLATE_WINDOW_SIZE - INFLATE_FASTINF_OUT)
while (state->AvailOut >= INFLATE_FASTINF_OUT && state->AvailIn >= INFLATE_FASTINF_IN && copyLen < INFLATE_FAST_COPY_MAX) {
Huffman_Unsafe_Decode(state, state->Table.Lits, lit);
if (lit <= 256) {
if (lit < 256) {
window[curIdx] = (uint8_t)lit;
state->AvailOut--; copyLen++;
curIdx = (curIdx + 1) & INFLATE_WINDOW_MASK;
} else {
state->State = Inflate_NextBlockState(state);
break;
}
} else {
lenIdx = lit - 257;
bits = len_bits[lenIdx];
Inflate_UNSAFE_EnsureBits(state, bits);
len = len_base[lenIdx] + Inflate_ReadBits(state, bits);
Huffman_Unsafe_Decode(state, state->TableDists, distIdx);
bits = dist_bits[distIdx];
Inflate_UNSAFE_EnsureBits(state, bits);
dist = dist_base[distIdx] + Inflate_ReadBits(state, bits);
/* Window is infinitely repeating like ... [xyz][xyz][xyz] ... */
/* If start and end don't cross a boundary, can avoid masking index */
startIdx = (curIdx - dist) & INFLATE_WINDOW_MASK;
if (curIdx >= startIdx && (curIdx + len) < INFLATE_WINDOW_SIZE) {
uint8_t* src = &window[startIdx];
uint8_t* dst = &window[curIdx];
for (i = 0; i < (len & ~0x3); i += 4) {
*dst++ = *src++; *dst++ = *src++; *dst++ = *src++; *dst++ = *src++;
}
for (; i < len; i++) { *dst++ = *src++; }
} else {
for (i = 0; i < len; i++) {
window[(curIdx + i) & INFLATE_WINDOW_MASK] = window[(startIdx + i) & INFLATE_WINDOW_MASK];
}
}
curIdx = (curIdx + len) & INFLATE_WINDOW_MASK;
state->AvailOut -= len; copyLen += len;
}
}
state->WindowIndex = curIdx;
if (!copyLen) return;
if (copyStart + copyLen < INFLATE_WINDOW_SIZE) {
Mem_Copy(state->Output, &state->Window[copyStart], copyLen);
state->Output += copyLen;
} else {
partLen = INFLATE_WINDOW_SIZE - copyStart;
Mem_Copy(state->Output, &state->Window[copyStart], partLen);
state->Output += partLen;
Mem_Copy(state->Output, state->Window, copyLen - partLen);
state->Output += (copyLen - partLen);
}
}
void Inflate_Process(struct InflateState* state) {
uint32_t len, dist, nlen;
uint32_t i, bits;
uint32_t blockHeader;
/* len/dist table variables */
uint32_t distIdx, lenIdx;
int lit;
/* code lens table variables */
uint32_t count, repeatCount;
uint8_t repeatValue;
/* window variables */
uint32_t startIdx, curIdx;
uint32_t copyLen, windowCopyLen;
for (;;) {
switch (state->State) {
case INFLATE_STATE_HEADER: {
Inflate_EnsureBits(state, 3);
blockHeader = Inflate_ReadBits(state, 3);
state->LastBlock = blockHeader & 1;
switch (blockHeader >> 1) {
case 0: { /* Uncompressed block */
Inflate_AlignBits(state);
state->State = INFLATE_STATE_UNCOMPRESSED_HEADER;
} break;
case 1: { /* Fixed/static huffman compressed */
Huffman_Build(&state->Table.Lits, fixed_lits, INFLATE_MAX_LITS);
Huffman_Build(&state->TableDists, fixed_dists, INFLATE_MAX_DISTS);
state->State = Inflate_NextCompressState(state);
} break;
case 2: { /* Dynamic huffman compressed */
state->State = INFLATE_STATE_DYNAMIC_HEADER;
} break;
case 3: {
Logger_Abort("DEFLATE - Invalid block type");
} break;
}
break;
}
case INFLATE_STATE_UNCOMPRESSED_HEADER: {
Inflate_EnsureBits(state, 32);
len = Inflate_ReadBits(state, 16);
nlen = Inflate_ReadBits(state, 16);
if (len != (nlen ^ 0xFFFFUL)) {
Logger_Abort("DEFLATE - Uncompressed block LEN check failed");
}
state->Index = len; /* Reuse for 'uncompressed length' */
state->State = INFLATE_STATE_UNCOMPRESSED_DATA;
}
case INFLATE_STATE_UNCOMPRESSED_DATA: {
/* read bits left in bit buffer (slow way) */
while (state->NumBits && state->AvailOut && state->Index) {
*state->Output = Inflate_ReadBits(state, 8);
state->Window[state->WindowIndex] = *state->Output;
state->WindowIndex = (state->WindowIndex + 1) & INFLATE_WINDOW_MASK;
state->Output++; state->AvailOut--; state->Index--;
}
if (!state->AvailIn || !state->AvailOut) return;
copyLen = min(state->AvailIn, state->AvailOut);
copyLen = min(copyLen, state->Index);
if (copyLen > 0) {
Mem_Copy(state->Output, state->NextIn, copyLen);
windowCopyLen = INFLATE_WINDOW_SIZE - state->WindowIndex;
windowCopyLen = min(windowCopyLen, copyLen);
Mem_Copy(&state->Window[state->WindowIndex], state->Output, windowCopyLen);
/* Wrap around remainder of copy to start from beginning of window */
if (windowCopyLen < copyLen) {
Mem_Copy(state->Window, &state->Output[windowCopyLen], copyLen - windowCopyLen);
}
state->WindowIndex = (state->WindowIndex + copyLen) & INFLATE_WINDOW_MASK;
state->Output += copyLen; state->AvailOut -= copyLen; state->Index -= copyLen;
state->NextIn += copyLen; state->AvailIn -= copyLen;
}
if (!state->Index) { state->State = Inflate_NextBlockState(state); }
break;
}
case INFLATE_STATE_DYNAMIC_HEADER: {
Inflate_EnsureBits(state, 14);
state->NumLits = 257 + Inflate_ReadBits(state, 5);
state->NumDists = 1 + Inflate_ReadBits(state, 5);
state->NumCodeLens = 4 + Inflate_ReadBits(state, 4);
state->Index = 0;
state->State = INFLATE_STATE_DYNAMIC_CODELENS;
}
case INFLATE_STATE_DYNAMIC_CODELENS: {
while (state->Index < state->NumCodeLens) {
Inflate_EnsureBits(state, 3);
i = codelens_order[state->Index];
state->Buffer[i] = Inflate_ReadBits(state, 3);
state->Index++;
}
for (i = state->NumCodeLens; i < INFLATE_MAX_CODELENS; i++) {
state->Buffer[codelens_order[i]] = 0;
}
state->Index = 0;
state->State = INFLATE_STATE_DYNAMIC_LITSDISTS;
Huffman_Build(&state->Table.CodeLens, state->Buffer, INFLATE_MAX_CODELENS);
}
case INFLATE_STATE_DYNAMIC_LITSDISTS: {
count = state->NumLits + state->NumDists;
while (state->Index < count) {
int bits = Huffman_Decode(state, &state->Table.CodeLens);
if (bits < 16) {
if (bits == -1) return;
state->Buffer[state->Index] = (uint8_t)bits;
state->Index++;
} else {
state->TmpCodeLens = bits;
state->State = INFLATE_STATE_DYNAMIC_LITSDISTSREPEAT;
break;
}
}
if (state->Index == count) {
state->Index = 0;
state->State = Inflate_NextCompressState(state);
Huffman_Build(&state->Table.Lits, state->Buffer, state->NumLits);
Huffman_Build(&state->TableDists, &state->Buffer[state->NumLits], state->NumDists);
}
break;
}
case INFLATE_STATE_DYNAMIC_LITSDISTSREPEAT: {
switch (state->TmpCodeLens) {
case 16:
Inflate_EnsureBits(state, 2);
repeatCount = Inflate_ReadBits(state, 2);
if (!state->Index) Logger_Abort("DEFLATE - Tried to repeat invalid byte");
repeatCount += 3; repeatValue = state->Buffer[state->Index - 1];
break;
case 17:
Inflate_EnsureBits(state, 3);
repeatCount = Inflate_ReadBits(state, 3);
repeatCount += 3; repeatValue = 0;
break;
case 18:
Inflate_EnsureBits(state, 7);
repeatCount = Inflate_ReadBits(state, 7);
repeatCount += 11; repeatValue = 0;
break;
}
count = state->NumLits + state->NumDists;
if (state->Index + repeatCount > count) {
Logger_Abort("DEFLATE - Tried to repeat past end");
}
Mem_Set(&state->Buffer[state->Index], repeatValue, repeatCount);
state->Index += repeatCount;
state->State = INFLATE_STATE_DYNAMIC_LITSDISTS;
break;
}
case INFLATE_STATE_COMPRESSED_LIT: {
if (!state->AvailOut) return;
lit = Huffman_Decode(state, &state->Table.Lits);
if (lit < 256) {
if (lit == -1) return;
*state->Output = (uint8_t)lit;
state->Window[state->WindowIndex] = (uint8_t)lit;
state->Output++; state->AvailOut--;
state->WindowIndex = (state->WindowIndex + 1) & INFLATE_WINDOW_MASK;
break;
} else if (lit == 256) {
state->State = Inflate_NextBlockState(state);
break;
} else {
state->TmpLit = lit - 257;
state->State = INFLATE_STATE_COMPRESSED_LITREPEAT;
}
}
case INFLATE_STATE_COMPRESSED_LITREPEAT: {
lenIdx = state->TmpLit;
bits = len_bits[lenIdx];
Inflate_EnsureBits(state, bits);
state->TmpLit = len_base[lenIdx] + Inflate_ReadBits(state, bits);
state->State = INFLATE_STATE_COMPRESSED_DIST;
}
case INFLATE_STATE_COMPRESSED_DIST: {
state->TmpDist = Huffman_Decode(state, &state->TableDists);
if (state->TmpDist == -1) return;
state->State = INFLATE_STATE_COMPRESSED_DISTREPEAT;
}
case INFLATE_STATE_COMPRESSED_DISTREPEAT: {
distIdx = state->TmpDist;
bits = dist_bits[distIdx];
Inflate_EnsureBits(state, bits);
state->TmpDist = dist_base[distIdx] + Inflate_ReadBits(state, bits);
state->State = INFLATE_STATE_COMPRESSED_DATA;
}
case INFLATE_STATE_COMPRESSED_DATA: {
if (!state->AvailOut) return;
len = state->TmpLit; dist = state->TmpDist;
len = min(len, state->AvailOut);
/* TODO: Should we test outside of the loop, whether a masking will be required or not? */
startIdx = (state->WindowIndex - dist) & INFLATE_WINDOW_MASK;
curIdx = state->WindowIndex;
for (i = 0; i < len; i++) {
uint8_t value = state->Window[(startIdx + i) & INFLATE_WINDOW_MASK];
*state->Output = value;
state->Window[(curIdx + i) & INFLATE_WINDOW_MASK] = value;
state->Output++;
}
state->WindowIndex = (curIdx + len) & INFLATE_WINDOW_MASK;
state->TmpLit -= len;
state->AvailOut -= len;
if (!state->TmpLit) { state->State = Inflate_NextCompressState(state); }
break;
}
case INFLATE_STATE_FASTCOMPRESSED: {
Inflate_InflateFast(state);
if (state->State == INFLATE_STATE_FASTCOMPRESSED) {
state->State = Inflate_NextCompressState(state);
}
break;
}
case INFLATE_STATE_DONE:
return;
}
}
}
static ReturnCode Inflate_StreamRead(struct Stream* stream, uint8_t* data, uint32_t count, uint32_t* modified) {
struct InflateState* state;
uint8_t* inputEnd;
uint32_t read, left;
uint32_t startAvailOut;
bool hasInput;
ReturnCode res;
*modified = 0;
state = stream->Meta.Inflate;
state->Output = data;
state->AvailOut = count;
hasInput = true;
while (state->AvailOut > 0 && hasInput) {
if (state->State == INFLATE_STATE_DONE) break;
if (!state->AvailIn) {
/* Fully used up input buffer. Cycle back to start. */
inputEnd = state->Input + INFLATE_MAX_INPUT;
if (state->NextIn == inputEnd) state->NextIn = state->Input;
left = (uint32_t)(inputEnd - state->NextIn);
res = state->Source->Read(state->Source, state->NextIn, left, &read);
if (res) return res;
/* Did we fail to read in more input data? Can't immediately return here, */
/* because there might be a few bits of data left in the bit buffer */
hasInput = read > 0;
state->AvailIn += read;
}
/* Reading data reduces available out */
startAvailOut = state->AvailOut;
Inflate_Process(state);
*modified += (startAvailOut - state->AvailOut);
}
return 0;
}
void Inflate_MakeStream(struct Stream* stream, struct InflateState* state, struct Stream* underlying) {
Stream_Init(stream);
Inflate_Init(state, underlying);
stream->Meta.Inflate = state;
stream->Read = Inflate_StreamRead;
}
/*########################################################################################################################*
*---------------------------------------------------Deflate (compress)----------------------------------------------------*
*#########################################################################################################################*/
/* Pushes given bits, but does not write them */
#define Deflate_PushBits(state, value, bits) state->Bits |= (value) << state->NumBits; state->NumBits += (bits);
/* Pushes bits of the huffman codeword bits for the given literal, but does not write them */
#define Deflate_PushLit(state, value) Deflate_PushBits(state, state->LitsCodewords[value], state->LitsLens[value])
/* Pushes given bits (reversing for huffman code), but does not write them */
#define Deflate_PushHuff(state, value, bits) Deflate_PushBits(state, Huffman_ReverseBits(value, bits), bits)
/* Writes given byte to output */
#define Deflate_WriteByte(state) *state->NextOut++ = state->Bits; state->AvailOut--; state->Bits >>= 8; state->NumBits -= 8;
/* Flushes bits in buffer to output buffer */
#define Deflate_FlushBits(state) while (state->NumBits >= 8) { Deflate_WriteByte(state); }
#define DEFLATE_MAX_MATCH_LEN 258
static int Deflate_MatchLen(uint8_t* a, uint8_t* b, int maxLen) {
int i = 0;
while (i < maxLen && *a == *b) { i++; a++; b++; }
return i;
}
static uint32_t Deflate_Hash(uint8_t* src) {
return (uint32_t)((src[0] << 8) ^ (src[1] << 4) ^ (src[2])) & DEFLATE_HASH_MASK;
}
static void Deflate_Lit(struct DeflateState* state, int lit) {
Deflate_PushLit(state, lit);
Deflate_FlushBits(state);
}
static void Deflate_LenDist(struct DeflateState* state, int len, int dist) {
int j;
len_base[29] = UInt16_MaxValue;
dist_base[30] = UInt16_MaxValue;
/* TODO: Remove this hack out into Deflate_FlushBlock */
/* TODO: is that hack even thread-safe */
/* TODO: Do we actually need the if (len_bits[j]) ????????? does writing 0 bits matter??? */
for (j = 0; len >= len_base[j + 1]; j++);
Deflate_PushLit(state, j + 257);
if (len_bits[j]) { Deflate_PushBits(state, len - len_base[j], len_bits[j]); }
Deflate_FlushBits(state);
for (j = 0; dist >= dist_base[j + 1]; j++);
Deflate_PushHuff(state, j, 5);
if (dist_bits[j]) { Deflate_PushBits(state, dist - dist_base[j], dist_bits[j]); }
Deflate_FlushBits(state);
len_base[29] = 0;
dist_base[30] = 0;
}
static ReturnCode Deflate_FlushBlock(struct DeflateState* state, int len) {
uint32_t hash, nextHash;
int bestLen, maxLen, matchLen;
int bestPos, pos, nextPos;
uint16_t oldHead;
uint8_t* src;
uint8_t* cur;
ReturnCode res;
if (!state->WroteHeader) {
state->WroteHeader = true;
Deflate_PushBits(state, 3, 3); /* final block TRUE, block type FIXED */
}
/* TODO: Hash chains should persist past one block flush */
Mem_Set(state->Head, 0, sizeof(state->Head));
Mem_Set(state->Prev, 0, sizeof(state->Prev));
/* Based off descriptions from http://www.gzip.org/algorithm.txt and
https://github.com/nothings/stb/blob/master/stb_image_write.h */
src = state->Input;
cur = src;
while (len > 3) {
hash = Deflate_Hash(cur);
maxLen = min(len, DEFLATE_MAX_MATCH_LEN);
bestLen = 3 - 1; /* Match must be at least 3 bytes */
bestPos = 0;
/* Find longest match starting at this byte */
pos = state->Head[hash];
while (pos != 0) { /* TODO: Need to limit chain length here */
matchLen = Deflate_MatchLen(&src[pos], cur, maxLen);
if (matchLen > bestLen) { bestLen = matchLen; bestPos = pos; }
pos = state->Prev[pos];
}
/* Insert this entry into the hash chain */
pos = (int)(cur - src);
oldHead = state->Head[hash];
state->Head[hash] = pos;
state->Prev[pos] = oldHead;
/* Lazy evaluation: Find longest match starting at next byte */
/* If that's longer than the longest match at current byte, throwaway this match */
if (bestPos && len > 2) {
nextHash = Deflate_Hash(cur + 1);
nextPos = state->Head[nextHash];
maxLen = min(len - 1, DEFLATE_MAX_MATCH_LEN);
while (nextPos != 0) { /* TODO: Need to limit chain length here */
matchLen = Deflate_MatchLen(&src[nextPos], cur + 1, maxLen);
if (matchLen > bestLen) { bestPos = 0; break; }
nextPos = state->Prev[nextPos];
}
}
if (bestPos) {
Deflate_LenDist(state, bestLen, pos - bestPos);
len -= bestLen; cur += bestLen;
} else {
Deflate_Lit(state, *cur);
len--; cur++;
}
/* leave room for a few bytes and literals at end */
if (state->AvailOut >= 20) continue;
res = Stream_Write(state->Dest, state->Output, DEFLATE_OUT_SIZE - state->AvailOut);
state->NextOut = state->Output;
state->AvailOut = DEFLATE_OUT_SIZE;
if (res) return res;
}
/* literals for last few bytes */
while (len > 0) {
Deflate_Lit(state, *cur);
len--; cur++;
}
state->InputPosition = 0;
res = Stream_Write(state->Dest, state->Output, DEFLATE_OUT_SIZE - state->AvailOut);
state->NextOut = state->Output;
state->AvailOut = DEFLATE_OUT_SIZE;
return res;
}
static ReturnCode Deflate_StreamWrite(struct Stream* stream, const uint8_t* data, uint32_t count, uint32_t* modified) {
struct DeflateState* state;
ReturnCode res;
state = stream->Meta.Inflate;
*modified = 0;
while (count > 0) {
uint8_t* dst = &state->Input[state->InputPosition];
uint32_t toWrite = count;
if (state->InputPosition + toWrite >= DEFLATE_BUFFER_SIZE) {
toWrite = DEFLATE_BUFFER_SIZE - state->InputPosition;
}
Mem_Copy(dst, data, toWrite);
count -= toWrite;
state->InputPosition += toWrite;
*modified += toWrite;
data += toWrite;
if (state->InputPosition == DEFLATE_BUFFER_SIZE) {
res = Deflate_FlushBlock(state, DEFLATE_BUFFER_SIZE);
if (res) return res;
}
}
return 0;
}
static ReturnCode Deflate_StreamClose(struct Stream* stream) {
struct DeflateState* state;
ReturnCode res;
state = stream->Meta.Inflate;
res = Deflate_FlushBlock(state, state->InputPosition);
if (res) return res;
/* Write huffman encoded "literal 256" to terminate symbols */
Deflate_PushLit(state, 256);
Deflate_FlushBits(state);
/* In case last byte still has a few extra bits */
if (state->NumBits) {
while (state->NumBits < 8) { Deflate_PushBits(state, 0, 1); }
Deflate_FlushBits(state);
}
return Stream_Write(state->Dest, state->Output, DEFLATE_OUT_SIZE - state->AvailOut);
}
/* Constructs a huffman encoding table (for values to codewords) */
static void Deflate_BuildTable(const uint8_t* lens, int count, uint16_t* codewords, uint8_t* bitlens) {
int i, j, offset, codeword;
struct HuffmanTable table;
Huffman_Build(&table, lens, count);
for (i = 0; i < INFLATE_MAX_BITS; i++) {
if (!table.EndCodewords[i]) continue;
count = table.EndCodewords[i] - table.FirstCodewords[i];
for (j = 0; j < count; j++) {
offset = table.Values[table.FirstOffsets[i] + j];
codeword = table.FirstCodewords[i] + j;
bitlens[offset] = i;
codewords[offset] = Huffman_ReverseBits(codeword, i);
}
}
}
void Deflate_MakeStream(struct Stream* stream, struct DeflateState* state, struct Stream* underlying) {
Stream_Init(stream);
stream->Meta.Inflate = state;
stream->Write = Deflate_StreamWrite;
stream->Close = Deflate_StreamClose;
state->InputPosition = 0;
state->Bits = 0;
state->NumBits = 0;
state->NextOut = state->Output;
state->AvailOut = DEFLATE_OUT_SIZE;
state->Dest = underlying;
state->WroteHeader = false;
Mem_Set(state->Head, 0, sizeof(state->Head));
Mem_Set(state->Prev, 0, sizeof(state->Prev));
Deflate_BuildTable(fixed_lits, INFLATE_MAX_LITS, state->LitsCodewords, state->LitsLens);
}
/*########################################################################################################################*
*-----------------------------------------------------GZip (compress)-----------------------------------------------------*
*#########################################################################################################################*/
static ReturnCode GZip_StreamClose(struct Stream* stream) {
uint8_t data[8];
struct GZipState* state = stream->Meta.Inflate;
ReturnCode res;
if ((res = Deflate_StreamClose(stream))) return res;
Stream_SetU32_LE(&data[0], state->Crc32 ^ 0xFFFFFFFFUL);
Stream_SetU32_LE(&data[4], state->Size);
return Stream_Write(state->Base.Dest, data, sizeof(data));
}