deb-libisal/include/igzip_lib.h

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#ifndef _IGZIP_H
#define _IGZIP_H

/**
 * @file igzip_lib.h
 *
 * @brief This file defines the igzip compression interface, a high performance
 * deflate compression interface for storage applications.
 *
 * Deflate is a widely used compression standard that can be used standalone, it
 * also forms the basis of gzip and zlib compression formats. Igzip supports the
 * following flush features:
 *
 * - No Flush: The default method where no flush is performed.
 *
 * - Sync flush: whereby isal_deflate() finishes the current deflate block at
 *   the end of each input buffer. The deflate block is byte aligned by
 *   appending an empty stored block.
 *
 * - Full flush: whereby isal_deflate() finishes and aligns the deflate block as
 *   in sync flush but also ensures that subsequent block's history does not
 *   look back beyond this point and new blocks are fully independent.
 *
 * Igzip's default configuration is:
 *
 * - 8K window size
 *
 * This option can be overridden to enable:
 *
 * - 32K window size, by adding \#define LARGE_WINDOW 1 in igzip_lib.h and
 *   \%define LARGE_WINDOW in options.asm, or via the command line with
 *   @verbatim gmake D="-D LARGE_WINDOW" @endverbatim on Linux and FreeBSD, or
 *   with @verbatim nmake -f Makefile.nmake D="-D LARGE_WINDOW" @endverbatim on
 *   Windows.
 *
 * KNOWN ISSUES:
 * - If building the code on Windows with the 32K window enabled, the
 *   /LARGEADDRESSAWARE:NO link option must be added.
 * - The 32K window isn't supported when used in a shared library.
 *
 */
#include <stdint.h>
#include "types.h"

#ifdef __cplusplus
extern "C" {
#endif

// Options:dir
// m - reschedule mem reads
// e b - bitbuff style
// t s x - compare style
// h - limit hash updates
// l - use longer huffman table
// f - fix cache read

#if defined(LARGE_WINDOW)
# define HIST_SIZE 32
#else
# define HIST_SIZE 8
#endif

/* bit buffer types
 * BITBUF8: (e) Always write 8 bytes of data
 * BITBUFB: (b) Always write data
 */
#if !(defined(USE_BITBUFB) || defined(USE_BITBUF8) || defined(USE_BITBUF_ELSE))
# define USE_BITBUFB
#endif

/* compare types
 * 1: ( ) original
 * 2: (t) with CMOV
 * 3: (s) with sttni
 * 4: (x) with xmm / pmovbmsk
 * 5: (y) with ymm / pmovbmsk (32-bytes at a time)
 */
# define LIMIT_HASH_UPDATE

/* (l) longer huffman table */
#define LONGER_HUFFTABLE

/* (f) fix cache read problem */
#define FIX_CACHE_READ

#if (HIST_SIZE > 8)
# undef LONGER_HUFFTABLE
#endif

#define IGZIP_K  1024
#define IGZIP_D  (HIST_SIZE * IGZIP_K)	/* Amount of history */
#define IGZIP_LA (17 * 16)		/* Max look-ahead, rounded up to 32 byte boundary */
#define BSIZE  (2*IGZIP_D + IGZIP_LA)	/* Nominal buffer size */

#define HASH_SIZE  IGZIP_D
#define HASH_MASK  (HASH_SIZE - 1)

#define SHORTEST_MATCH  3

#define IGZIP_MAX_DEF_HDR_SIZE 328

#ifdef LONGER_HUFFTABLE
enum {DIST_TABLE_SIZE = 8*1024};

/* DECODE_OFFSET is dist code index corresponding to DIST_TABLE_SIZE + 1 */
enum { DECODE_OFFSET = 26 };
#else
enum {DIST_TABLE_SIZE = 1024};
/* DECODE_OFFSET is dist code index corresponding to DIST_TABLE_SIZE + 1 */
enum { DECODE_OFFSET = 20 };
#endif
enum {LEN_TABLE_SIZE = 256};
enum {LIT_TABLE_SIZE = 257};

#define IGZIP_LIT_LEN 286
#define IGZIP_DIST_LEN 30

/* Flush Flags */
#define NO_FLUSH	0	/* Default */
#define SYNC_FLUSH	1
#define FULL_FLUSH	2
#define FINISH_FLUSH	0	/* Deprecated */

/* Return values */
#define COMP_OK 0
#define INVALID_FLUSH -7
#define INVALID_PARAM -8
#define STATELESS_OVERFLOW -1
#define DEFLATE_HDR_LEN 3
/**
 *  @enum isal_zstate
 *  @brief Compression State please note ZSTATE_TRL only applies for GZIP compression
 */


/* When the state is set to ZSTATE_NEW_HDR or TMP_ZSTATE_NEW_HEADER, the
 * hufftable being used for compression may be swapped
 */
enum isal_zstate_state {
	ZSTATE_NEW_HDR,  //!< Header to be written
	ZSTATE_HDR,	//!< Header state
	ZSTATE_BODY,	//!< Body state
	ZSTATE_FLUSH_READ_BUFFER, //!< Flush buffer
	ZSTATE_SYNC_FLUSH, //!< Write sync flush block
	ZSTATE_FLUSH_WRITE_BUFFER, //!< Flush bitbuf
	ZSTATE_TRL,	//!< Trailer state
	ZSTATE_END,	//!< End state
	ZSTATE_TMP_NEW_HDR, //!< Temporary Header to be written
	ZSTATE_TMP_HDR,	//!< Temporary Header state
	ZSTATE_TMP_BODY,	//!< Temporary Body state
	ZSTATE_TMP_FLUSH_READ_BUFFER, //!< Flush buffer
	ZSTATE_TMP_SYNC_FLUSH, //!< Write sync flush block
	ZSTATE_TMP_FLUSH_WRITE_BUFFER, //!< Flush bitbuf
	ZSTATE_TMP_TRL,	//!< Temporary Trailer state
	ZSTATE_TMP_END	//!< Temporary End state
};

/* Offset used to switch between TMP states and non-tmp states */
#define TMP_OFFSET_SIZE ZSTATE_TMP_HDR - ZSTATE_HDR

struct isal_huff_histogram {
	uint64_t lit_len_histogram[IGZIP_LIT_LEN];
	uint64_t dist_histogram[IGZIP_DIST_LEN];
};

/** @brief Holds Bit Buffer information*/
struct BitBuf2 {
	uint64_t m_bits;	//!< bits in the bit buffer
	uint32_t m_bit_count;	//!< number of valid bits in the bit buffer
	uint8_t *m_out_buf;	//!< current index of buffer to write to
	uint8_t *m_out_end;	//!< end of buffer to write to
	uint8_t *m_out_start;	//!< start of buffer to write to
};

/* Variable prefixes:
 * b_ : Measured wrt the start of the buffer
 * f_ : Measured wrt the start of the file (aka file_start)
 */

/** @brief Holds the internal state information for input and output compression streams*/
struct isal_zstate {
	uint32_t b_bytes_valid;	//!< number of bytes of valid data in buffer
	uint32_t b_bytes_processed;	//!< keeps track of the number of bytes processed in isal_zstate.buffer
	uint8_t *file_start;	//!< pointer to where file would logically start
	DECLARE_ALIGNED(uint32_t crc[16], 16);	//!< actually 4 128-bit integers
	struct BitBuf2 bitbuf;	//!< Bit Buffer
	enum isal_zstate_state state;	//!< Current state in processing the data stream
	uint32_t count;	//!< used for partial header/trailer writes
	uint8_t tmp_out_buff[16];	//!< temporary array
	uint32_t tmp_out_start;	//!< temporary variable
	uint32_t tmp_out_end;	//!< temporary variable
	uint32_t last_flush;    //!< keeps track of last submitted flush
	uint32_t has_gzip_hdr;	//!< keeps track of if the gzip header has been written.
	uint32_t has_eob;	//!< keeps track of eob on the last deflate block
	uint32_t has_eob_hdr;	//!< keeps track of eob hdr (with BFINAL set)
	uint32_t left_over;	//!< keeps track of overflow bytes



	DECLARE_ALIGNED(uint8_t buffer[BSIZE + 16], 32);	//!< Internal buffer

	DECLARE_ALIGNED(uint16_t head[HASH_SIZE], 16);	//!< Hash array

};

/** @brief Holds the huffman tree used to huffman encode the input stream **/
struct isal_hufftables {

	uint8_t deflate_hdr[IGZIP_MAX_DEF_HDR_SIZE]; //!< deflate huffman tree header
	uint32_t deflate_hdr_count; //!< Number of whole bytes in deflate_huff_hdr
	uint32_t deflate_hdr_extra_bits; //!< Number of bits in the partial byte in header
	uint32_t dist_table[DIST_TABLE_SIZE]; //!< bits 4:0 are the code length, bits 31:5 are the code
	uint32_t len_table[LEN_TABLE_SIZE]; //!< bits 4:0 are the code length, bits 31:5 are the code
	uint16_t lit_table[LIT_TABLE_SIZE]; //!< literal code
	uint8_t lit_table_sizes[LIT_TABLE_SIZE]; //!< literal code length
	uint16_t dcodes[30 - DECODE_OFFSET]; //!< distance code
	uint8_t dcodes_sizes[30 - DECODE_OFFSET]; //!< distance code length

};

/** @brief Holds stream information*/
struct isal_zstream {
	uint8_t *next_in;	//!< Next input byte
	uint32_t avail_in;	//!< number of bytes available at next_in
	uint32_t total_in;	//!< total number of bytes read so far

	uint8_t *next_out;	//!< Next output byte
	uint32_t avail_out;	//!< number of bytes available at next_out
	uint32_t total_out;	//!< total number of bytes written so far

	struct isal_hufftables *hufftables; //!< Huffman encoding used when compressing
	uint32_t end_of_stream;	//!< non-zero if this is the last input buffer
	uint32_t flush;	//!< Flush type can be NO_FLUSH or SYNC_FLUSH

	struct isal_zstate internal_state;	//!< Internal state for this stream
};


/**
 * @brief Updates histograms to include the symbols found in the input
 * stream. Since this function only updates the histograms, it can be called on
 * multiple streams to get a histogram better representing the desired data
 * set. When first using histogram it must be initialized by zeroing the
 * structure.
 *
 * @param in_stream: Input stream of data.
 * @param length: The length of start_stream.
 * @param histogram: The returned histogram of lit/len/dist symbols.
 */
void isal_update_histogram(uint8_t * in_stream, int length, struct isal_huff_histogram * histogram);


/**
 * @brief Creates a custom huffman code for the given histograms in which
 *  every literal and repeat length is assigned a code and all possible lookback
 *  distances are assigned a code.
 *
 * @param hufftables: the output structure containing the huffman code
 * @param lit_histogram: histogram containing frequency of literal symbols and
 * repeat lengths
 * @param dist_histogram: histogram containing frequency of of lookback distances
 * @returns Returns a non zero value if an invalid huffman code was created.
 */
int isal_create_hufftables(struct isal_hufftables * hufftables,
			struct isal_huff_histogram * histogram);

/**
 * @brief Creates a custom huffman code for the given histograms like
 * isal_create_hufftables() except literals with 0 frequency in the histogram
 * are not assigned a code
 *
 * @param hufftables: the output structure containing the huffman code
 * @param lit_histogram: histogram containing frequency of literal symbols and
 * repeat lengths
 * @param dist_histogram: histogram containing frequency of of lookback distances
 * @returns Returns a non zero value if an invalid huffman code was created.
 */
int isal_create_hufftables_subset(struct isal_hufftables * hufftables,
				struct isal_huff_histogram * histogram);

/**
 * @brief Initialize compression stream data structure
 *
 * @param stream Structure holding state information on the compression streams.
 * @returns none
 */
void isal_deflate_init(struct isal_zstream *stream);


/**
 * @brief Fast data (deflate) compression for storage applications.
 *
 * On entry to isal_deflate(), next_in points to an input buffer and avail_in
 * indicates the length of that buffer. Similarly next_out points to an empty
 * output buffer and avail_out indicates the size of that buffer.
 *
 * The fields total_in and total_out start at 0 and are updated by
 * isal_deflate(). These reflect the total number of bytes read or written so far.
 *
 * The call to isal_deflate() will take data from the input buffer (updating
 * next_in, avail_in and write a compressed stream to the output buffer
 * (updating next_out and avail_out). The function returns when either the input
 * buffer is empty or the output buffer is full.
 *
 * When the last input buffer is passed in, signaled by setting the
 * end_of_stream, the routine will complete compression at the end of the input
 * buffer, as long as the output buffer is big enough.
 *
 * The equivalent of the zlib FLUSH_SYNC operation is currently supported.
 * Flush types can be NO_FLUSH or SYNC_FLUSH. Default flush type is NO_FLUSH.
 * If SYNC_FLUSH is selected each input buffer is compressed and byte aligned
 * with a type 0 block appended to the end. Switching between NO_FLUSH and
 * SYNC_FLUSH is supported to select after which input buffer a SYNC_FLUSH is
 * performed.
 *
 * @param  stream Structure holding state information on the compression streams.
 * @return COMP_OK (if everything is ok),
 *         INVALID_FLUSH (if an invalid FLUSH is selected),
 */
int isal_deflate(struct isal_zstream *stream);


/**
 * @brief Fast data (deflate) stateless compression for storage applications.
 *
 * Stateless (one shot) compression routine with a similar interface to
 * isal_deflate() but operates on entire input buffer at one time. Parameter
 * avail_out must be large enough to fit the entire compressed output. Max
 * expansion is limited to the input size plus the header size of a stored/raw
 * block.
 *
 * @param  stream Structure holding state information on the compression streams.
 * @return COMP_OK (if everything is ok),
 *         STATELESS_OVERFLOW (if output buffer will not fit output).
 */
int isal_deflate_stateless(struct isal_zstream *stream);


#ifdef __cplusplus
}
#endif
#endif	/* ifndef _IGZIP_H */