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Diffstat (limited to 'include/import/slz.h')
| -rw-r--r-- | include/import/slz.h | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/include/import/slz.h b/include/import/slz.h new file mode 100644 index 0000000..901a790 --- /dev/null +++ b/include/import/slz.h @@ -0,0 +1,200 @@ +/* + * Copyright (C) 2013-2015 Willy Tarreau <w@1wt.eu> + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sublicense, and/or sell copies of the Software, and to + * permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES + * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT + * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, + * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + */ + +#ifndef _SLZ_H +#define _SLZ_H + +#include <inttypes.h> + +/* We have two macros UNALIGNED_LE_OK and UNALIGNED_FASTER. The latter indicates + * that using unaligned data is faster than a simple shift. On x86 32-bit at + * least it is not the case as the per-byte access is 30% faster. A core2-duo on + * x86_64 is 7% faster to read one byte + shifting by 8 than to read one word, + * but a core i5 is 7% faster doing the unaligned read, so we privilege more + * recent implementations here. + */ +#if defined(__x86_64__) +#define UNALIGNED_LE_OK +#define UNALIGNED_FASTER +#define USE_64BIT_QUEUE +#elif defined(__i386__) || defined(__i486__) || defined(__i586__) || defined(__i686__) +#define UNALIGNED_LE_OK +//#define UNALIGNED_FASTER +#elif defined(__ARMEL__) && defined(__ARM_ARCH_7A__) +#define UNALIGNED_LE_OK +#define UNALIGNED_FASTER +#elif defined(__ARM_ARCH_8A) || defined(__ARM_FEATURE_UNALIGNED) +#define UNALIGNED_LE_OK +#define UNALIGNED_FASTER +#endif + +/* Log2 of the size of the hash table used for the references table. */ +#define HASH_BITS 13 + +enum slz_state { + SLZ_ST_INIT, /* stream initialized */ + SLZ_ST_EOB, /* header or end of block already sent */ + SLZ_ST_FIXED, /* inside a fixed huffman sequence */ + SLZ_ST_LAST, /* last block, BFINAL sent */ + SLZ_ST_DONE, /* BFINAL+EOB sent BFINAL */ + SLZ_ST_END /* end sent (BFINAL, EOB, CRC + len) */ +}; + +enum { + SLZ_FMT_GZIP, /* RFC1952: gzip envelope and crc32 for CRC */ + SLZ_FMT_ZLIB, /* RFC1950: zlib envelope and adler-32 for CRC */ + SLZ_FMT_DEFLATE, /* RFC1951: raw deflate, and no crc */ +}; + +struct slz_stream { +#ifdef USE_64BIT_QUEUE + uint64_t queue; /* last pending bits, LSB first */ +#else + uint32_t queue; /* last pending bits, LSB first */ +#endif + uint32_t qbits; /* number of bits in queue, < 8 on 32-bit, < 32 on 64-bit */ + unsigned char *outbuf; /* set by encode() */ + uint16_t state; /* one of slz_state */ + uint8_t level:1; /* 0 = no compression, 1 = compression */ + uint8_t format:2; /* SLZ_FMT_* */ + uint8_t unused1; /* unused for now */ + uint32_t crc32; + uint32_t ilen; +}; + +/* Functions specific to rfc1951 (deflate) */ +long slz_rfc1951_encode(struct slz_stream *strm, unsigned char *out, const unsigned char *in, long ilen, int more); +int slz_rfc1951_init(struct slz_stream *strm, int level); +int slz_rfc1951_flush(struct slz_stream *strm, unsigned char *buf); +int slz_rfc1951_finish(struct slz_stream *strm, unsigned char *buf); + +/* Functions specific to rfc1952 (gzip) */ +uint32_t slz_crc32_by1(uint32_t crc, const unsigned char *buf, int len); +uint32_t slz_crc32_by4(uint32_t crc, const unsigned char *buf, int len); +long slz_rfc1952_encode(struct slz_stream *strm, unsigned char *out, const unsigned char *in, long ilen, int more); +int slz_rfc1952_send_header(struct slz_stream *strm, unsigned char *buf); +int slz_rfc1952_init(struct slz_stream *strm, int level); +int slz_rfc1952_flush(struct slz_stream *strm, unsigned char *buf); +int slz_rfc1952_finish(struct slz_stream *strm, unsigned char *buf); + +/* Functions specific to rfc1950 (zlib) */ +uint32_t slz_adler32_by1(uint32_t crc, const unsigned char *buf, int len); +uint32_t slz_adler32_block(uint32_t crc, const unsigned char *buf, long len); +long slz_rfc1950_encode(struct slz_stream *strm, unsigned char *out, const unsigned char *in, long ilen, int more); +int slz_rfc1950_send_header(struct slz_stream *strm, unsigned char *buf); +int slz_rfc1950_init(struct slz_stream *strm, int level); +int slz_rfc1950_flush(struct slz_stream *strm, unsigned char *buf); +int slz_rfc1950_finish(struct slz_stream *strm, unsigned char *buf); + +/* generic functions */ + +/* Initializes stream <strm>. It will configure the stream to use format + * <format> for the data, which must be one of SLZ_FMT_*. The compression level + * passed in <level> is set. This value can only be 0 (no compression) or 1 + * (compression) and other values will lead to unpredictable behaviour. The + * function should always return 0. + */ +static inline int slz_init(struct slz_stream *strm, int level, int format) +{ + int ret; + + if (format == SLZ_FMT_GZIP) + ret = slz_rfc1952_init(strm, level); + else if (format == SLZ_FMT_ZLIB) + ret = slz_rfc1950_init(strm, level); + else { /* deflate for anything else */ + ret = slz_rfc1951_init(strm, level); + strm->format = format; + } + return ret; +} + +/* Encodes the block according to the format used by the stream. This means + * that the CRC of the input block may be computed according to the CRC32 or + * adler-32 algorithms. The number of output bytes is returned. + */ +static inline long slz_encode(struct slz_stream *strm, void *out, + const void *in, long ilen, int more) +{ + long ret; + + if (strm->format == SLZ_FMT_GZIP) + ret = slz_rfc1952_encode(strm, (unsigned char *) out, (const unsigned char *) in, ilen, more); + else if (strm->format == SLZ_FMT_ZLIB) + ret = slz_rfc1950_encode(strm, (unsigned char *) out, (const unsigned char *) in, ilen, more); + else /* deflate for other ones */ + ret = slz_rfc1951_encode(strm, (unsigned char *) out, (const unsigned char *) in, ilen, more); + + return ret; +} + +/* Flushes pending bits and sends the trailer for stream <strm> into buffer + * <buf> if needed. When it's done, the stream state is updated to SLZ_ST_END. + * It returns the number of bytes emitted. The trailer consists in flushing the + * possibly pending bits from the queue (up to 24 bits), rounding to the next + * byte, then 4 bytes for the CRC when doing zlib/gzip, then another 4 bytes + * for the input length for gzip. That may about to 4+4+4 = 12 bytes, that the + * caller must ensure are available before calling the function. Note that if + * the initial header was never sent, it will be sent first as well (up to 10 + * extra bytes). + */ +static inline int slz_finish(struct slz_stream *strm, void *buf) +{ + int ret; + + if (strm->format == SLZ_FMT_GZIP) + ret = slz_rfc1952_finish(strm, (unsigned char *) buf); + else if (strm->format == SLZ_FMT_ZLIB) + ret = slz_rfc1950_finish(strm, (unsigned char *) buf); + else /* deflate for other ones */ + ret = slz_rfc1951_finish(strm, (unsigned char *) buf); + + return ret; +} + +/* Flushes any pending data for stream <strm> into buffer <buf>, then emits an + * empty literal block to byte-align the output, allowing to completely flush + * the queue. Note that if the initial header was never sent, it will be sent + * first as well (0, 2 or 10 extra bytes). This requires that the output buffer + * still has this plus the size of the queue available (up to 4 bytes), plus + * one byte for (BFINAL,BTYPE), plus 4 bytes for LEN+NLEN, or a total of 19 + * bytes in the worst case. The number of bytes emitted is returned. It is + * guaranteed that the queue is empty on return. This may cause some overhead + * by adding needless 5-byte blocks if called to often. + */ +static inline int slz_flush(struct slz_stream *strm, void *buf) +{ + int ret; + + if (strm->format == SLZ_FMT_GZIP) + ret = slz_rfc1952_flush(strm, (unsigned char *) buf); + else if (strm->format == SLZ_FMT_ZLIB) + ret = slz_rfc1950_flush(strm, (unsigned char *) buf); + else /* deflate for other ones */ + ret = slz_rfc1951_flush(strm, (unsigned char *) buf); + + return ret; +} + +#endif |