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authorAnton Samokhvalov <pg83@yandex.ru>2022-02-10 16:45:15 +0300
committerDaniil Cherednik <dcherednik@yandex-team.ru>2022-02-10 16:45:15 +0300
commit72cb13b4aff9bc9cf22e49251bc8fd143f82538f (patch)
treeda2c34829458c7d4e74bdfbdf85dff449e9e7fb8 /contrib/libs/zstd06/common/fse_static.h
parent778e51ba091dc39e7b7fcab2b9cf4dbedfb6f2b5 (diff)
downloadydb-72cb13b4aff9bc9cf22e49251bc8fd143f82538f.tar.gz
Restoring authorship annotation for Anton Samokhvalov <pg83@yandex.ru>. Commit 1 of 2.
Diffstat (limited to 'contrib/libs/zstd06/common/fse_static.h')
-rw-r--r--contrib/libs/zstd06/common/fse_static.h682
1 files changed, 341 insertions, 341 deletions
diff --git a/contrib/libs/zstd06/common/fse_static.h b/contrib/libs/zstd06/common/fse_static.h
index d09589efee..9ecb0b2cb9 100644
--- a/contrib/libs/zstd06/common/fse_static.h
+++ b/contrib/libs/zstd06/common/fse_static.h
@@ -1,340 +1,340 @@
#include <contrib/libs/zstd06/renames.h>
-/* ******************************************************************
- FSE : Finite State Entropy coder
- header file for static linking (only)
- Copyright (C) 2013-2015, Yann Collet
-
- BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
-
- Redistribution and use in source and binary forms, with or without
- modification, are permitted provided that the following conditions are
- met:
-
- * Redistributions of source code must retain the above copyright
- notice, this list of conditions and the following disclaimer.
- * Redistributions in binary form must reproduce the above
- copyright notice, this list of conditions and the following disclaimer
- in the documentation and/or other materials provided with the
- distribution.
-
- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
- You can contact the author at :
- - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
- - Public forum : https://groups.google.com/forum/#!forum/lz4c
-****************************************************************** */
-#ifndef FSE_STATIC_H
-#define FSE_STATIC_H
-
-#if defined (__cplusplus)
-extern "C" {
-#endif
-
-
-/* *****************************************
-* Dependencies
-*******************************************/
-#include "fse.h"
-#include "bitstream.h"
-
-
-/* *****************************************
-* Static allocation
-*******************************************/
-/* FSE buffer bounds */
-#define FSE_NCOUNTBOUND 512
-#define FSE_BLOCKBOUND(size) (size + (size>>7))
-#define FSE_COMPRESSBOUND(size) (FSE_NCOUNTBOUND + FSE_BLOCKBOUND(size)) /* Macro version, useful for static allocation */
-
-/* It is possible to statically allocate FSE CTable/DTable as a table of unsigned using below macros */
-#define FSE_CTABLE_SIZE_U32(maxTableLog, maxSymbolValue) (1 + (1<<(maxTableLog-1)) + ((maxSymbolValue+1)*2))
-#define FSE_DTABLE_SIZE_U32(maxTableLog) (1 + (1<<maxTableLog))
-
-
-/* *****************************************
-* FSE advanced API
-*******************************************/
-size_t FSE_countFast(unsigned* count, unsigned* maxSymbolValuePtr, const void* src, size_t srcSize);
-/* same as FSE_count(), but blindly trusts that all byte values within src are <= *maxSymbolValuePtr */
-
-size_t FSE_buildCTable_raw (FSE_CTable* ct, unsigned nbBits);
-/* build a fake FSE_CTable, designed to not compress an input, where each symbol uses nbBits */
-
-size_t FSE_buildCTable_rle (FSE_CTable* ct, unsigned char symbolValue);
-/* build a fake FSE_CTable, designed to compress always the same symbolValue */
-
-size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits);
-/* build a fake FSE_DTable, designed to read an uncompressed bitstream where each symbol uses nbBits */
-
-size_t FSE_buildDTable_rle (FSE_DTable* dt, unsigned char symbolValue);
-/* build a fake FSE_DTable, designed to always generate the same symbolValue */
-
-
-/* *****************************************
-* FSE symbol compression API
-*******************************************/
-/*!
- This API consists of small unitary functions, which highly benefit from being inlined.
- You will want to enable link-time-optimization to ensure these functions are properly inlined in your binary.
- Visual seems to do it automatically.
- For gcc or clang, you'll need to add -flto flag at compilation and linking stages.
- If none of these solutions is applicable, include "fse.c" directly.
-*/
-typedef struct
-{
- ptrdiff_t value;
- const void* stateTable;
- const void* symbolTT;
- unsigned stateLog;
-} FSE_CState_t;
-
-static void FSE_initCState(FSE_CState_t* CStatePtr, const FSE_CTable* ct);
-
-static void FSE_encodeSymbol(BIT_CStream_t* bitC, FSE_CState_t* CStatePtr, unsigned symbol);
-
-static void FSE_flushCState(BIT_CStream_t* bitC, const FSE_CState_t* CStatePtr);
-
-/*!
-These functions are inner components of FSE_compress_usingCTable().
-They allow the creation of custom streams, mixing multiple tables and bit sources.
-
-A key property to keep in mind is that encoding and decoding are done **in reverse direction**.
-So the first symbol you will encode is the last you will decode, like a LIFO stack.
-
-You will need a few variables to track your CStream. They are :
-
-FSE_CTable ct; // Provided by FSE_buildCTable()
-BIT_CStream_t bitStream; // bitStream tracking structure
-FSE_CState_t state; // State tracking structure (can have several)
-
-
-The first thing to do is to init bitStream and state.
- size_t errorCode = BIT_initCStream(&bitStream, dstBuffer, maxDstSize);
- FSE_initCState(&state, ct);
-
-Note that BIT_initCStream() can produce an error code, so its result should be tested, using FSE_isError();
-You can then encode your input data, byte after byte.
-FSE_encodeSymbol() outputs a maximum of 'tableLog' bits at a time.
-Remember decoding will be done in reverse direction.
- FSE_encodeByte(&bitStream, &state, symbol);
-
-At any time, you can also add any bit sequence.
-Note : maximum allowed nbBits is 25, for compatibility with 32-bits decoders
- BIT_addBits(&bitStream, bitField, nbBits);
-
-The above methods don't commit data to memory, they just store it into local register, for speed.
-Local register size is 64-bits on 64-bits systems, 32-bits on 32-bits systems (size_t).
-Writing data to memory is a manual operation, performed by the flushBits function.
- BIT_flushBits(&bitStream);
-
-Your last FSE encoding operation shall be to flush your last state value(s).
- FSE_flushState(&bitStream, &state);
-
-Finally, you must close the bitStream.
-The function returns the size of CStream in bytes.
-If data couldn't fit into dstBuffer, it will return a 0 ( == not compressible)
-If there is an error, it returns an errorCode (which can be tested using FSE_isError()).
- size_t size = BIT_closeCStream(&bitStream);
-*/
-
-
-/* *****************************************
-* FSE symbol decompression API
-*******************************************/
-typedef struct
-{
- size_t state;
- const void* table; /* precise table may vary, depending on U16 */
-} FSE_DState_t;
-
-
-static void FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt);
-
-static unsigned char FSE_decodeSymbol(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD);
-
-static unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr);
-
-/*!
-Let's now decompose FSE_decompress_usingDTable() into its unitary components.
-You will decode FSE-encoded symbols from the bitStream,
-and also any other bitFields you put in, **in reverse order**.
-
-You will need a few variables to track your bitStream. They are :
-
-BIT_DStream_t DStream; // Stream context
-FSE_DState_t DState; // State context. Multiple ones are possible
-FSE_DTable* DTablePtr; // Decoding table, provided by FSE_buildDTable()
-
-The first thing to do is to init the bitStream.
- errorCode = BIT_initDStream(&DStream, srcBuffer, srcSize);
-
-You should then retrieve your initial state(s)
-(in reverse flushing order if you have several ones) :
- errorCode = FSE_initDState(&DState, &DStream, DTablePtr);
-
-You can then decode your data, symbol after symbol.
-For information the maximum number of bits read by FSE_decodeSymbol() is 'tableLog'.
-Keep in mind that symbols are decoded in reverse order, like a LIFO stack (last in, first out).
- unsigned char symbol = FSE_decodeSymbol(&DState, &DStream);
-
-You can retrieve any bitfield you eventually stored into the bitStream (in reverse order)
-Note : maximum allowed nbBits is 25, for 32-bits compatibility
- size_t bitField = BIT_readBits(&DStream, nbBits);
-
-All above operations only read from local register (which size depends on size_t).
-Refueling the register from memory is manually performed by the reload method.
- endSignal = FSE_reloadDStream(&DStream);
-
-BIT_reloadDStream() result tells if there is still some more data to read from DStream.
-BIT_DStream_unfinished : there is still some data left into the DStream.
-BIT_DStream_endOfBuffer : Dstream reached end of buffer. Its container may no longer be completely filled.
-BIT_DStream_completed : Dstream reached its exact end, corresponding in general to decompression completed.
-BIT_DStream_tooFar : Dstream went too far. Decompression result is corrupted.
-
-When reaching end of buffer (BIT_DStream_endOfBuffer), progress slowly, notably if you decode multiple symbols per loop,
-to properly detect the exact end of stream.
-After each decoded symbol, check if DStream is fully consumed using this simple test :
- BIT_reloadDStream(&DStream) >= BIT_DStream_completed
-
-When it's done, verify decompression is fully completed, by checking both DStream and the relevant states.
-Checking if DStream has reached its end is performed by :
- BIT_endOfDStream(&DStream);
-Check also the states. There might be some symbols left there, if some high probability ones (>50%) are possible.
- FSE_endOfDState(&DState);
-*/
-
-
-/* *****************************************
-* FSE unsafe API
-*******************************************/
-static unsigned char FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD);
-/* faster, but works only if nbBits is always >= 1 (otherwise, result will be corrupted) */
-
-
-/* *****************************************
-* Implementation of inlined functions
-*******************************************/
-typedef struct {
- int deltaFindState;
- U32 deltaNbBits;
-} FSE_symbolCompressionTransform; /* total 8 bytes */
-
-MEM_STATIC void FSE_initCState(FSE_CState_t* statePtr, const FSE_CTable* ct)
-{
- const void* ptr = ct;
- const U16* u16ptr = (const U16*) ptr;
- const U32 tableLog = MEM_read16(ptr);
- statePtr->value = (ptrdiff_t)1<<tableLog;
- statePtr->stateTable = u16ptr+2;
- statePtr->symbolTT = ((const U32*)ct + 1 + (tableLog ? (1<<(tableLog-1)) : 1));
- statePtr->stateLog = tableLog;
-}
-
-MEM_STATIC void FSE_initCState2(FSE_CState_t* statePtr, const FSE_CTable* ct, U32 symbol)
-{
- FSE_initCState(statePtr, ct);
- {
- const FSE_symbolCompressionTransform symbolTT = ((const FSE_symbolCompressionTransform*)(statePtr->symbolTT))[symbol];
- const U16* stateTable = (const U16*)(statePtr->stateTable);
- U32 nbBitsOut = (U32)((symbolTT.deltaNbBits + (1<<15)) >> 16);
- statePtr->value = (nbBitsOut << 16) - symbolTT.deltaNbBits;
- statePtr->value = stateTable[(statePtr->value >> nbBitsOut) + symbolTT.deltaFindState];
-
- }
-}
-
-MEM_STATIC void FSE_encodeSymbol(BIT_CStream_t* bitC, FSE_CState_t* statePtr, U32 symbol)
-{
- const FSE_symbolCompressionTransform symbolTT = ((const FSE_symbolCompressionTransform*)(statePtr->symbolTT))[symbol];
- const U16* const stateTable = (const U16*)(statePtr->stateTable);
- U32 nbBitsOut = (U32)((statePtr->value + symbolTT.deltaNbBits) >> 16);
- BIT_addBits(bitC, statePtr->value, nbBitsOut);
- statePtr->value = stateTable[ (statePtr->value >> nbBitsOut) + symbolTT.deltaFindState];
-}
-
-MEM_STATIC void FSE_flushCState(BIT_CStream_t* bitC, const FSE_CState_t* statePtr)
-{
- BIT_addBits(bitC, statePtr->value, statePtr->stateLog);
- BIT_flushBits(bitC);
-}
-
-/*<===== Decompression =====>*/
-
-typedef struct {
- U16 tableLog;
- U16 fastMode;
-} FSE_DTableHeader; /* sizeof U32 */
-
-typedef struct
-{
- unsigned short newState;
- unsigned char symbol;
- unsigned char nbBits;
-} FSE_decode_t; /* size == U32 */
-
-MEM_STATIC void FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt)
-{
- const void* ptr = dt;
- const FSE_DTableHeader* const DTableH = (const FSE_DTableHeader*)ptr;
- DStatePtr->state = BIT_readBits(bitD, DTableH->tableLog);
- BIT_reloadDStream(bitD);
- DStatePtr->table = dt + 1;
-}
-
-MEM_STATIC BYTE FSE_peekSymbol(const FSE_DState_t* DStatePtr)
-{
- FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
- return DInfo.symbol;
-}
-
-MEM_STATIC void FSE_updateState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
-{
- FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
- U32 const nbBits = DInfo.nbBits;
- size_t const lowBits = BIT_readBits(bitD, nbBits);
- DStatePtr->state = DInfo.newState + lowBits;
-}
-
-MEM_STATIC BYTE FSE_decodeSymbol(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
-{
- FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
- U32 const nbBits = DInfo.nbBits;
- BYTE const symbol = DInfo.symbol;
- size_t const lowBits = BIT_readBits(bitD, nbBits);
-
- DStatePtr->state = DInfo.newState + lowBits;
- return symbol;
-}
-
-/*! FSE_decodeSymbolFast() :
- unsafe, only works if no symbol has a probability > 50% */
-MEM_STATIC BYTE FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
-{
- FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
- U32 const nbBits = DInfo.nbBits;
- BYTE const symbol = DInfo.symbol;
- size_t const lowBits = BIT_readBitsFast(bitD, nbBits);
-
- DStatePtr->state = DInfo.newState + lowBits;
- return symbol;
-}
-
-MEM_STATIC unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr)
-{
- return DStatePtr->state == 0;
-}
-
-
+/* ******************************************************************
+ FSE : Finite State Entropy coder
+ header file for static linking (only)
+ Copyright (C) 2013-2015, Yann Collet
+
+ BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are
+ met:
+
+ * Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above
+ copyright notice, this list of conditions and the following disclaimer
+ in the documentation and/or other materials provided with the
+ distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+ You can contact the author at :
+ - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
+ - Public forum : https://groups.google.com/forum/#!forum/lz4c
+****************************************************************** */
+#ifndef FSE_STATIC_H
+#define FSE_STATIC_H
+
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
+
+/* *****************************************
+* Dependencies
+*******************************************/
+#include "fse.h"
+#include "bitstream.h"
+
+
+/* *****************************************
+* Static allocation
+*******************************************/
+/* FSE buffer bounds */
+#define FSE_NCOUNTBOUND 512
+#define FSE_BLOCKBOUND(size) (size + (size>>7))
+#define FSE_COMPRESSBOUND(size) (FSE_NCOUNTBOUND + FSE_BLOCKBOUND(size)) /* Macro version, useful for static allocation */
+
+/* It is possible to statically allocate FSE CTable/DTable as a table of unsigned using below macros */
+#define FSE_CTABLE_SIZE_U32(maxTableLog, maxSymbolValue) (1 + (1<<(maxTableLog-1)) + ((maxSymbolValue+1)*2))
+#define FSE_DTABLE_SIZE_U32(maxTableLog) (1 + (1<<maxTableLog))
+
+
+/* *****************************************
+* FSE advanced API
+*******************************************/
+size_t FSE_countFast(unsigned* count, unsigned* maxSymbolValuePtr, const void* src, size_t srcSize);
+/* same as FSE_count(), but blindly trusts that all byte values within src are <= *maxSymbolValuePtr */
+
+size_t FSE_buildCTable_raw (FSE_CTable* ct, unsigned nbBits);
+/* build a fake FSE_CTable, designed to not compress an input, where each symbol uses nbBits */
+
+size_t FSE_buildCTable_rle (FSE_CTable* ct, unsigned char symbolValue);
+/* build a fake FSE_CTable, designed to compress always the same symbolValue */
+
+size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits);
+/* build a fake FSE_DTable, designed to read an uncompressed bitstream where each symbol uses nbBits */
+
+size_t FSE_buildDTable_rle (FSE_DTable* dt, unsigned char symbolValue);
+/* build a fake FSE_DTable, designed to always generate the same symbolValue */
+
+
+/* *****************************************
+* FSE symbol compression API
+*******************************************/
+/*!
+ This API consists of small unitary functions, which highly benefit from being inlined.
+ You will want to enable link-time-optimization to ensure these functions are properly inlined in your binary.
+ Visual seems to do it automatically.
+ For gcc or clang, you'll need to add -flto flag at compilation and linking stages.
+ If none of these solutions is applicable, include "fse.c" directly.
+*/
+typedef struct
+{
+ ptrdiff_t value;
+ const void* stateTable;
+ const void* symbolTT;
+ unsigned stateLog;
+} FSE_CState_t;
+
+static void FSE_initCState(FSE_CState_t* CStatePtr, const FSE_CTable* ct);
+
+static void FSE_encodeSymbol(BIT_CStream_t* bitC, FSE_CState_t* CStatePtr, unsigned symbol);
+
+static void FSE_flushCState(BIT_CStream_t* bitC, const FSE_CState_t* CStatePtr);
+
+/*!
+These functions are inner components of FSE_compress_usingCTable().
+They allow the creation of custom streams, mixing multiple tables and bit sources.
+
+A key property to keep in mind is that encoding and decoding are done **in reverse direction**.
+So the first symbol you will encode is the last you will decode, like a LIFO stack.
+
+You will need a few variables to track your CStream. They are :
+
+FSE_CTable ct; // Provided by FSE_buildCTable()
+BIT_CStream_t bitStream; // bitStream tracking structure
+FSE_CState_t state; // State tracking structure (can have several)
+
+
+The first thing to do is to init bitStream and state.
+ size_t errorCode = BIT_initCStream(&bitStream, dstBuffer, maxDstSize);
+ FSE_initCState(&state, ct);
+
+Note that BIT_initCStream() can produce an error code, so its result should be tested, using FSE_isError();
+You can then encode your input data, byte after byte.
+FSE_encodeSymbol() outputs a maximum of 'tableLog' bits at a time.
+Remember decoding will be done in reverse direction.
+ FSE_encodeByte(&bitStream, &state, symbol);
+
+At any time, you can also add any bit sequence.
+Note : maximum allowed nbBits is 25, for compatibility with 32-bits decoders
+ BIT_addBits(&bitStream, bitField, nbBits);
+
+The above methods don't commit data to memory, they just store it into local register, for speed.
+Local register size is 64-bits on 64-bits systems, 32-bits on 32-bits systems (size_t).
+Writing data to memory is a manual operation, performed by the flushBits function.
+ BIT_flushBits(&bitStream);
+
+Your last FSE encoding operation shall be to flush your last state value(s).
+ FSE_flushState(&bitStream, &state);
+
+Finally, you must close the bitStream.
+The function returns the size of CStream in bytes.
+If data couldn't fit into dstBuffer, it will return a 0 ( == not compressible)
+If there is an error, it returns an errorCode (which can be tested using FSE_isError()).
+ size_t size = BIT_closeCStream(&bitStream);
+*/
+
+
+/* *****************************************
+* FSE symbol decompression API
+*******************************************/
+typedef struct
+{
+ size_t state;
+ const void* table; /* precise table may vary, depending on U16 */
+} FSE_DState_t;
+
+
+static void FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt);
+
+static unsigned char FSE_decodeSymbol(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD);
+
+static unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr);
+
+/*!
+Let's now decompose FSE_decompress_usingDTable() into its unitary components.
+You will decode FSE-encoded symbols from the bitStream,
+and also any other bitFields you put in, **in reverse order**.
+
+You will need a few variables to track your bitStream. They are :
+
+BIT_DStream_t DStream; // Stream context
+FSE_DState_t DState; // State context. Multiple ones are possible
+FSE_DTable* DTablePtr; // Decoding table, provided by FSE_buildDTable()
+
+The first thing to do is to init the bitStream.
+ errorCode = BIT_initDStream(&DStream, srcBuffer, srcSize);
+
+You should then retrieve your initial state(s)
+(in reverse flushing order if you have several ones) :
+ errorCode = FSE_initDState(&DState, &DStream, DTablePtr);
+
+You can then decode your data, symbol after symbol.
+For information the maximum number of bits read by FSE_decodeSymbol() is 'tableLog'.
+Keep in mind that symbols are decoded in reverse order, like a LIFO stack (last in, first out).
+ unsigned char symbol = FSE_decodeSymbol(&DState, &DStream);
+
+You can retrieve any bitfield you eventually stored into the bitStream (in reverse order)
+Note : maximum allowed nbBits is 25, for 32-bits compatibility
+ size_t bitField = BIT_readBits(&DStream, nbBits);
+
+All above operations only read from local register (which size depends on size_t).
+Refueling the register from memory is manually performed by the reload method.
+ endSignal = FSE_reloadDStream(&DStream);
+
+BIT_reloadDStream() result tells if there is still some more data to read from DStream.
+BIT_DStream_unfinished : there is still some data left into the DStream.
+BIT_DStream_endOfBuffer : Dstream reached end of buffer. Its container may no longer be completely filled.
+BIT_DStream_completed : Dstream reached its exact end, corresponding in general to decompression completed.
+BIT_DStream_tooFar : Dstream went too far. Decompression result is corrupted.
+
+When reaching end of buffer (BIT_DStream_endOfBuffer), progress slowly, notably if you decode multiple symbols per loop,
+to properly detect the exact end of stream.
+After each decoded symbol, check if DStream is fully consumed using this simple test :
+ BIT_reloadDStream(&DStream) >= BIT_DStream_completed
+
+When it's done, verify decompression is fully completed, by checking both DStream and the relevant states.
+Checking if DStream has reached its end is performed by :
+ BIT_endOfDStream(&DStream);
+Check also the states. There might be some symbols left there, if some high probability ones (>50%) are possible.
+ FSE_endOfDState(&DState);
+*/
+
+
+/* *****************************************
+* FSE unsafe API
+*******************************************/
+static unsigned char FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD);
+/* faster, but works only if nbBits is always >= 1 (otherwise, result will be corrupted) */
+
+
+/* *****************************************
+* Implementation of inlined functions
+*******************************************/
+typedef struct {
+ int deltaFindState;
+ U32 deltaNbBits;
+} FSE_symbolCompressionTransform; /* total 8 bytes */
+
+MEM_STATIC void FSE_initCState(FSE_CState_t* statePtr, const FSE_CTable* ct)
+{
+ const void* ptr = ct;
+ const U16* u16ptr = (const U16*) ptr;
+ const U32 tableLog = MEM_read16(ptr);
+ statePtr->value = (ptrdiff_t)1<<tableLog;
+ statePtr->stateTable = u16ptr+2;
+ statePtr->symbolTT = ((const U32*)ct + 1 + (tableLog ? (1<<(tableLog-1)) : 1));
+ statePtr->stateLog = tableLog;
+}
+
+MEM_STATIC void FSE_initCState2(FSE_CState_t* statePtr, const FSE_CTable* ct, U32 symbol)
+{
+ FSE_initCState(statePtr, ct);
+ {
+ const FSE_symbolCompressionTransform symbolTT = ((const FSE_symbolCompressionTransform*)(statePtr->symbolTT))[symbol];
+ const U16* stateTable = (const U16*)(statePtr->stateTable);
+ U32 nbBitsOut = (U32)((symbolTT.deltaNbBits + (1<<15)) >> 16);
+ statePtr->value = (nbBitsOut << 16) - symbolTT.deltaNbBits;
+ statePtr->value = stateTable[(statePtr->value >> nbBitsOut) + symbolTT.deltaFindState];
+
+ }
+}
+
+MEM_STATIC void FSE_encodeSymbol(BIT_CStream_t* bitC, FSE_CState_t* statePtr, U32 symbol)
+{
+ const FSE_symbolCompressionTransform symbolTT = ((const FSE_symbolCompressionTransform*)(statePtr->symbolTT))[symbol];
+ const U16* const stateTable = (const U16*)(statePtr->stateTable);
+ U32 nbBitsOut = (U32)((statePtr->value + symbolTT.deltaNbBits) >> 16);
+ BIT_addBits(bitC, statePtr->value, nbBitsOut);
+ statePtr->value = stateTable[ (statePtr->value >> nbBitsOut) + symbolTT.deltaFindState];
+}
+
+MEM_STATIC void FSE_flushCState(BIT_CStream_t* bitC, const FSE_CState_t* statePtr)
+{
+ BIT_addBits(bitC, statePtr->value, statePtr->stateLog);
+ BIT_flushBits(bitC);
+}
+
+/*<===== Decompression =====>*/
+
+typedef struct {
+ U16 tableLog;
+ U16 fastMode;
+} FSE_DTableHeader; /* sizeof U32 */
+
+typedef struct
+{
+ unsigned short newState;
+ unsigned char symbol;
+ unsigned char nbBits;
+} FSE_decode_t; /* size == U32 */
+
+MEM_STATIC void FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt)
+{
+ const void* ptr = dt;
+ const FSE_DTableHeader* const DTableH = (const FSE_DTableHeader*)ptr;
+ DStatePtr->state = BIT_readBits(bitD, DTableH->tableLog);
+ BIT_reloadDStream(bitD);
+ DStatePtr->table = dt + 1;
+}
+
+MEM_STATIC BYTE FSE_peekSymbol(const FSE_DState_t* DStatePtr)
+{
+ FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
+ return DInfo.symbol;
+}
+
+MEM_STATIC void FSE_updateState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
+{
+ FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
+ U32 const nbBits = DInfo.nbBits;
+ size_t const lowBits = BIT_readBits(bitD, nbBits);
+ DStatePtr->state = DInfo.newState + lowBits;
+}
+
+MEM_STATIC BYTE FSE_decodeSymbol(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
+{
+ FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
+ U32 const nbBits = DInfo.nbBits;
+ BYTE const symbol = DInfo.symbol;
+ size_t const lowBits = BIT_readBits(bitD, nbBits);
+
+ DStatePtr->state = DInfo.newState + lowBits;
+ return symbol;
+}
+
+/*! FSE_decodeSymbolFast() :
+ unsafe, only works if no symbol has a probability > 50% */
+MEM_STATIC BYTE FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
+{
+ FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
+ U32 const nbBits = DInfo.nbBits;
+ BYTE const symbol = DInfo.symbol;
+ size_t const lowBits = BIT_readBitsFast(bitD, nbBits);
+
+ DStatePtr->state = DInfo.newState + lowBits;
+ return symbol;
+}
+
+MEM_STATIC unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr)
+{
+ return DStatePtr->state == 0;
+}
+
+
#ifndef FSE_COMMONDEFS_ONLY
@@ -383,8 +383,8 @@ MEM_STATIC unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr)
#define FSE_TABLESTEP(tableSize) ((tableSize>>1) + (tableSize>>3) + 3)
-#if defined (__cplusplus)
-}
-#endif
-
-#endif /* FSE_STATIC_H */
+#if defined (__cplusplus)
+}
+#endif
+
+#endif /* FSE_STATIC_H */