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332 lines
12 KiB
C
332 lines
12 KiB
C
/* Bcj2.h -- BCJ2 converter for x86 code (Branch CALL/JUMP variant2)
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2023-03-02 : Igor Pavlov : Public domain */
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#ifndef ZIP7_INC_BCJ2_H
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#define ZIP7_INC_BCJ2_H
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#include "7zTypes.h"
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EXTERN_C_BEGIN
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#define BCJ2_NUM_STREAMS 4
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enum
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{
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BCJ2_STREAM_MAIN,
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BCJ2_STREAM_CALL,
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BCJ2_STREAM_JUMP,
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BCJ2_STREAM_RC
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};
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enum
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{
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BCJ2_DEC_STATE_ORIG_0 = BCJ2_NUM_STREAMS,
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BCJ2_DEC_STATE_ORIG_1,
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BCJ2_DEC_STATE_ORIG_2,
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BCJ2_DEC_STATE_ORIG_3,
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BCJ2_DEC_STATE_ORIG,
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BCJ2_DEC_STATE_ERROR /* after detected data error */
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};
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enum
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{
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BCJ2_ENC_STATE_ORIG = BCJ2_NUM_STREAMS,
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BCJ2_ENC_STATE_FINISHED /* it's state after fully encoded stream */
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};
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/* #define BCJ2_IS_32BIT_STREAM(s) ((s) == BCJ2_STREAM_CALL || (s) == BCJ2_STREAM_JUMP) */
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#define BCJ2_IS_32BIT_STREAM(s) ((unsigned)((unsigned)(s) - (unsigned)BCJ2_STREAM_CALL) < 2)
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/*
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CBcj2Dec / CBcj2Enc
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bufs sizes:
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BUF_SIZE(n) = lims[n] - bufs[n]
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bufs sizes for BCJ2_STREAM_CALL and BCJ2_STREAM_JUMP must be multiply of 4:
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(BUF_SIZE(BCJ2_STREAM_CALL) & 3) == 0
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(BUF_SIZE(BCJ2_STREAM_JUMP) & 3) == 0
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*/
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// typedef UInt32 CBcj2Prob;
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typedef UInt16 CBcj2Prob;
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/*
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BCJ2 encoder / decoder internal requirements:
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- If last bytes of stream contain marker (e8/e8/0f8x), then
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there is also encoded symbol (0 : no conversion) in RC stream.
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- One case of overlapped instructions is supported,
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if last byte of converted instruction is (0f) and next byte is (8x):
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marker [xx xx xx 0f] 8x
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then the pair (0f 8x) is treated as marker.
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*/
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/* ---------- BCJ2 Decoder ---------- */
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/*
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CBcj2Dec:
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(dest) is allowed to overlap with bufs[BCJ2_STREAM_MAIN], with the following conditions:
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bufs[BCJ2_STREAM_MAIN] >= dest &&
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bufs[BCJ2_STREAM_MAIN] - dest >=
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BUF_SIZE(BCJ2_STREAM_CALL) +
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BUF_SIZE(BCJ2_STREAM_JUMP)
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reserve = bufs[BCJ2_STREAM_MAIN] - dest -
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( BUF_SIZE(BCJ2_STREAM_CALL) +
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BUF_SIZE(BCJ2_STREAM_JUMP) )
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and additional conditions:
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if (it's first call of Bcj2Dec_Decode() after Bcj2Dec_Init())
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{
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(reserve != 1) : if (ver < v23.00)
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}
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else // if there are more than one calls of Bcj2Dec_Decode() after Bcj2Dec_Init())
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{
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(reserve >= 6) : if (ver < v23.00)
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(reserve >= 4) : if (ver >= v23.00)
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We need that (reserve) because after first call of Bcj2Dec_Decode(),
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CBcj2Dec::temp can contain up to 4 bytes for writing to (dest).
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}
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(reserve == 0) is allowed, if we decode full stream via single call of Bcj2Dec_Decode().
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(reserve == 0) also is allowed in case of multi-call, if we use fixed buffers,
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and (reserve) is calculated from full (final) sizes of all streams before first call.
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*/
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typedef struct
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{
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const Byte *bufs[BCJ2_NUM_STREAMS];
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const Byte *lims[BCJ2_NUM_STREAMS];
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Byte *dest;
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const Byte *destLim;
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unsigned state; /* BCJ2_STREAM_MAIN has more priority than BCJ2_STATE_ORIG */
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UInt32 ip; /* property of starting base for decoding */
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UInt32 temp; /* Byte temp[4]; */
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UInt32 range;
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UInt32 code;
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CBcj2Prob probs[2 + 256];
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} CBcj2Dec;
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/* Note:
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Bcj2Dec_Init() sets (CBcj2Dec::ip = 0)
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if (ip != 0) property is required, the caller must set CBcj2Dec::ip after Bcj2Dec_Init()
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*/
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void Bcj2Dec_Init(CBcj2Dec *p);
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/* Bcj2Dec_Decode():
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returns:
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SZ_OK
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SZ_ERROR_DATA : if data in 5 starting bytes of BCJ2_STREAM_RC stream are not correct
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*/
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SRes Bcj2Dec_Decode(CBcj2Dec *p);
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/* To check that decoding was finished you can compare
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sizes of processed streams with sizes known from another sources.
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You must do at least one mandatory check from the two following options:
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- the check for size of processed output (ORIG) stream.
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- the check for size of processed input (MAIN) stream.
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additional optional checks:
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- the checks for processed sizes of all input streams (MAIN, CALL, JUMP, RC)
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- the checks Bcj2Dec_IsMaybeFinished*()
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also before actual decoding you can check that the
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following condition is met for stream sizes:
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( size(ORIG) == size(MAIN) + size(CALL) + size(JUMP) )
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*/
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/* (state == BCJ2_STREAM_MAIN) means that decoder is ready for
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additional input data in BCJ2_STREAM_MAIN stream.
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Note that (state == BCJ2_STREAM_MAIN) is allowed for non-finished decoding.
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*/
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#define Bcj2Dec_IsMaybeFinished_state_MAIN(_p_) ((_p_)->state == BCJ2_STREAM_MAIN)
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/* if the stream decoding was finished correctly, then range decoder
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part of CBcj2Dec also was finished, and then (CBcj2Dec::code == 0).
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Note that (CBcj2Dec::code == 0) is allowed for non-finished decoding.
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*/
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#define Bcj2Dec_IsMaybeFinished_code(_p_) ((_p_)->code == 0)
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/* use Bcj2Dec_IsMaybeFinished() only as additional check
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after at least one mandatory check from the two following options:
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- the check for size of processed output (ORIG) stream.
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- the check for size of processed input (MAIN) stream.
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*/
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#define Bcj2Dec_IsMaybeFinished(_p_) ( \
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Bcj2Dec_IsMaybeFinished_state_MAIN(_p_) && \
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Bcj2Dec_IsMaybeFinished_code(_p_))
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/* ---------- BCJ2 Encoder ---------- */
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typedef enum
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{
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BCJ2_ENC_FINISH_MODE_CONTINUE,
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BCJ2_ENC_FINISH_MODE_END_BLOCK,
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BCJ2_ENC_FINISH_MODE_END_STREAM
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} EBcj2Enc_FinishMode;
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/*
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BCJ2_ENC_FINISH_MODE_CONTINUE:
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process non finished encoding.
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It notifies the encoder that additional further calls
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can provide more input data (src) than provided by current call.
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In that case the CBcj2Enc encoder still can move (src) pointer
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up to (srcLim), but CBcj2Enc encoder can store some of the last
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processed bytes (up to 4 bytes) from src to internal CBcj2Enc::temp[] buffer.
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at return:
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(CBcj2Enc::src will point to position that includes
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processed data and data copied to (temp[]) buffer)
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That data from (temp[]) buffer will be used in further calls.
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BCJ2_ENC_FINISH_MODE_END_BLOCK:
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finish encoding of current block (ended at srcLim) without RC flushing.
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at return: if (CBcj2Enc::state == BCJ2_ENC_STATE_ORIG) &&
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CBcj2Enc::src == CBcj2Enc::srcLim)
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: it shows that block encoding was finished. And the encoder is
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ready for new (src) data or for stream finish operation.
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finished block means
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{
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CBcj2Enc has completed block encoding up to (srcLim).
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(1 + 4 bytes) or (2 + 4 bytes) CALL/JUMP cortages will
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not cross block boundary at (srcLim).
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temporary CBcj2Enc buffer for (ORIG) src data is empty.
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3 output uncompressed streams (MAIN, CALL, JUMP) were flushed.
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RC stream was not flushed. And RC stream will cross block boundary.
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}
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Note: some possible implementation of BCJ2 encoder could
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write branch marker (e8/e8/0f8x) in one call of Bcj2Enc_Encode(),
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and it could calculate symbol for RC in another call of Bcj2Enc_Encode().
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BCJ2 encoder uses ip/fileIp/fileSize/relatLimit values to calculate RC symbol.
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And these CBcj2Enc variables can have different values in different Bcj2Enc_Encode() calls.
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So caller must finish each block with BCJ2_ENC_FINISH_MODE_END_BLOCK
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to ensure that RC symbol is calculated and written in proper block.
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BCJ2_ENC_FINISH_MODE_END_STREAM
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finish encoding of stream (ended at srcLim) fully including RC flushing.
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at return: if (CBcj2Enc::state == BCJ2_ENC_STATE_FINISHED)
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: it shows that stream encoding was finished fully,
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and all output streams were flushed fully.
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also Bcj2Enc_IsFinished() can be called.
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*/
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/*
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32-bit relative offset in JUMP/CALL commands is
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- (mod 4 GiB) for 32-bit x86 code
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- signed Int32 for 64-bit x86-64 code
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BCJ2 encoder also does internal relative to absolute address conversions.
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And there are 2 possible ways to do it:
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before v23: we used 32-bit variables and (mod 4 GiB) conversion
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since v23: we use 64-bit variables and (signed Int32 offset) conversion.
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The absolute address condition for conversion in v23:
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((UInt64)((Int64)ip64 - (Int64)fileIp64 + 5 + (Int32)offset) < (UInt64)fileSize64)
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note that if (fileSize64 > 2 GiB). there is difference between
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old (mod 4 GiB) way (v22) and new (signed Int32 offset) way (v23).
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And new (v23) way is more suitable to encode 64-bit x86-64 code for (fileSize64 > 2 GiB) cases.
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*/
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/*
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// for old (v22) way for conversion:
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typedef UInt32 CBcj2Enc_ip_unsigned;
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typedef Int32 CBcj2Enc_ip_signed;
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#define BCJ2_ENC_FileSize_MAX ((UInt32)1 << 31)
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*/
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typedef UInt64 CBcj2Enc_ip_unsigned;
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typedef Int64 CBcj2Enc_ip_signed;
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/* maximum size of file that can be used for conversion condition */
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#define BCJ2_ENC_FileSize_MAX ((CBcj2Enc_ip_unsigned)0 - 2)
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/* default value of fileSize64_minus1 variable that means
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that absolute address limitation will not be used */
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#define BCJ2_ENC_FileSizeField_UNLIMITED ((CBcj2Enc_ip_unsigned)0 - 1)
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/* calculate value that later can be set to CBcj2Enc::fileSize64_minus1 */
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#define BCJ2_ENC_GET_FileSizeField_VAL_FROM_FileSize(fileSize) \
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((CBcj2Enc_ip_unsigned)(fileSize) - 1)
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/* set CBcj2Enc::fileSize64_minus1 variable from size of file */
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#define Bcj2Enc_SET_FileSize(p, fileSize) \
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(p)->fileSize64_minus1 = BCJ2_ENC_GET_FileSizeField_VAL_FROM_FileSize(fileSize);
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typedef struct
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{
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Byte *bufs[BCJ2_NUM_STREAMS];
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const Byte *lims[BCJ2_NUM_STREAMS];
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const Byte *src;
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const Byte *srcLim;
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unsigned state;
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EBcj2Enc_FinishMode finishMode;
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Byte context;
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Byte flushRem;
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Byte isFlushState;
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Byte cache;
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UInt32 range;
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UInt64 low;
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UInt64 cacheSize;
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// UInt32 context; // for marker version, it can include marker flag.
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/* (ip64) and (fileIp64) correspond to virtual source stream position
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that doesn't include data in temp[] */
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CBcj2Enc_ip_unsigned ip64; /* current (ip) position */
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CBcj2Enc_ip_unsigned fileIp64; /* start (ip) position of current file */
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CBcj2Enc_ip_unsigned fileSize64_minus1; /* size of current file (for conversion limitation) */
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UInt32 relatLimit; /* (relatLimit <= ((UInt32)1 << 31)) : 0 means disable_conversion */
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// UInt32 relatExcludeBits;
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UInt32 tempTarget;
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unsigned tempPos; /* the number of bytes that were copied to temp[] buffer
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(tempPos <= 4) outside of Bcj2Enc_Encode() */
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// Byte temp[4]; // for marker version
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Byte temp[8];
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CBcj2Prob probs[2 + 256];
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} CBcj2Enc;
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void Bcj2Enc_Init(CBcj2Enc *p);
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/*
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Bcj2Enc_Encode(): at exit:
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p->State < BCJ2_NUM_STREAMS : we need more buffer space for output stream
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(bufs[p->State] == lims[p->State])
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p->State == BCJ2_ENC_STATE_ORIG : we need more data in input src stream
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(src == srcLim)
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p->State == BCJ2_ENC_STATE_FINISHED : after fully encoded stream
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*/
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void Bcj2Enc_Encode(CBcj2Enc *p);
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/* Bcj2Enc encoder can look ahead for up 4 bytes of source stream.
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CBcj2Enc::tempPos : is the number of bytes that were copied from input stream to temp[] buffer.
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(CBcj2Enc::src) after Bcj2Enc_Encode() is starting position after
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fully processed data and after data copied to temp buffer.
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So if the caller needs to get real number of fully processed input
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bytes (without look ahead data in temp buffer),
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the caller must subtruct (CBcj2Enc::tempPos) value from processed size
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value that is calculated based on current (CBcj2Enc::src):
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cur_processed_pos = Calc_Big_Processed_Pos(enc.src)) -
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Bcj2Enc_Get_AvailInputSize_in_Temp(&enc);
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*/
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/* get the size of input data that was stored in temp[] buffer: */
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#define Bcj2Enc_Get_AvailInputSize_in_Temp(p) ((p)->tempPos)
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#define Bcj2Enc_IsFinished(p) ((p)->flushRem == 0)
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/* Note : the decoder supports overlapping of marker (0f 80).
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But we can eliminate such overlapping cases by setting
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the limit for relative offset conversion as
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CBcj2Enc::relatLimit <= (0x0f << 24) == (240 MiB)
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*/
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/* default value for CBcj2Enc::relatLimit */
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#define BCJ2_ENC_RELAT_LIMIT_DEFAULT ((UInt32)0x0f << 24)
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#define BCJ2_ENC_RELAT_LIMIT_MAX ((UInt32)1 << 31)
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// #define BCJ2_RELAT_EXCLUDE_NUM_BITS 5
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EXTERN_C_END
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#endif
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