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Diffstat (limited to 'fluent-bit/lib/librdkafka-2.1.0/src/snappy.c')
| -rw-r--r-- | fluent-bit/lib/librdkafka-2.1.0/src/snappy.c | 1866 |
1 files changed, 0 insertions, 1866 deletions
diff --git a/fluent-bit/lib/librdkafka-2.1.0/src/snappy.c b/fluent-bit/lib/librdkafka-2.1.0/src/snappy.c deleted file mode 100644 index e3988b18..00000000 --- a/fluent-bit/lib/librdkafka-2.1.0/src/snappy.c +++ /dev/null @@ -1,1866 +0,0 @@ -/* - * C port of the snappy compressor from Google. - * This is a very fast compressor with comparable compression to lzo. - * Works best on 64bit little-endian, but should be good on others too. - * Ported by Andi Kleen. - * Uptodate with snappy 1.1.0 - */ - -/* - * Copyright 2005 Google Inc. All Rights Reserved. - * - * 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. - * * Neither the name of Google Inc. nor the names of its - * contributors may be used to endorse or promote products derived from - * this software without specific prior written permission. - * - * 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. - */ - -#ifdef __GNUC__ -#pragma GCC diagnostic push -#pragma GCC diagnostic ignored "-Wcast-align" -#endif - -#ifndef SG -#define SG /* Scatter-Gather / iovec support in Snappy */ -#endif - -#ifdef __KERNEL__ -#include <linux/kernel.h> -#ifdef SG -#include <linux/uio.h> -#endif -#include <linux/module.h> -#include <linux/slab.h> -#include <linux/string.h> -#include <linux/snappy.h> -#include <linux/vmalloc.h> -#include <asm/unaligned.h> -#else -#include "snappy.h" -#include "snappy_compat.h" -#endif - -#include "rd.h" - -#ifdef _MSC_VER -#define inline __inline -#endif - -static inline u64 get_unaligned64(const void *b) -{ - u64 ret; - memcpy(&ret, b, sizeof(u64)); - return ret; -} -static inline u32 get_unaligned32(const void *b) -{ - u32 ret; - memcpy(&ret, b, sizeof(u32)); - return ret; -} -#define get_unaligned_le32(x) (le32toh(get_unaligned32((u32 *)(x)))) - -static inline void put_unaligned64(u64 v, void *b) -{ - memcpy(b, &v, sizeof(v)); -} -static inline void put_unaligned32(u32 v, void *b) -{ - memcpy(b, &v, sizeof(v)); -} -static inline void put_unaligned16(u16 v, void *b) -{ - memcpy(b, &v, sizeof(v)); -} -#define put_unaligned_le16(v,x) (put_unaligned16(htole16(v), (u16 *)(x))) - - -#define CRASH_UNLESS(x) BUG_ON(!(x)) -#define CHECK(cond) CRASH_UNLESS(cond) -#define CHECK_LE(a, b) CRASH_UNLESS((a) <= (b)) -#define CHECK_GE(a, b) CRASH_UNLESS((a) >= (b)) -#define CHECK_EQ(a, b) CRASH_UNLESS((a) == (b)) -#define CHECK_NE(a, b) CRASH_UNLESS((a) != (b)) -#define CHECK_LT(a, b) CRASH_UNLESS((a) < (b)) -#define CHECK_GT(a, b) CRASH_UNLESS((a) > (b)) - -#define UNALIGNED_LOAD32(_p) get_unaligned32((u32 *)(_p)) -#define UNALIGNED_LOAD64(_p) get_unaligned64((u64 *)(_p)) - -#define UNALIGNED_STORE16(_p, _val) put_unaligned16(_val, (u16 *)(_p)) -#define UNALIGNED_STORE32(_p, _val) put_unaligned32(_val, (u32 *)(_p)) -#define UNALIGNED_STORE64(_p, _val) put_unaligned64(_val, (u64 *)(_p)) - -/* - * This can be more efficient than UNALIGNED_LOAD64 + UNALIGNED_STORE64 - * on some platforms, in particular ARM. - */ -static inline void unaligned_copy64(const void *src, void *dst) -{ - if (sizeof(void *) == 8) { - UNALIGNED_STORE64(dst, UNALIGNED_LOAD64(src)); - } else { - const char *src_char = (const char *)(src); - char *dst_char = (char *)(dst); - - UNALIGNED_STORE32(dst_char, UNALIGNED_LOAD32(src_char)); - UNALIGNED_STORE32(dst_char + 4, UNALIGNED_LOAD32(src_char + 4)); - } -} - -#ifdef NDEBUG - -#define DCHECK(cond) do {} while(0) -#define DCHECK_LE(a, b) do {} while(0) -#define DCHECK_GE(a, b) do {} while(0) -#define DCHECK_EQ(a, b) do {} while(0) -#define DCHECK_NE(a, b) do {} while(0) -#define DCHECK_LT(a, b) do {} while(0) -#define DCHECK_GT(a, b) do {} while(0) - -#else - -#define DCHECK(cond) CHECK(cond) -#define DCHECK_LE(a, b) CHECK_LE(a, b) -#define DCHECK_GE(a, b) CHECK_GE(a, b) -#define DCHECK_EQ(a, b) CHECK_EQ(a, b) -#define DCHECK_NE(a, b) CHECK_NE(a, b) -#define DCHECK_LT(a, b) CHECK_LT(a, b) -#define DCHECK_GT(a, b) CHECK_GT(a, b) - -#endif - -static inline bool is_little_endian(void) -{ -#ifdef __LITTLE_ENDIAN__ - return true; -#endif - return false; -} - -#if defined(__xlc__) // xlc compiler on AIX -#define rd_clz(n) __cntlz4(n) -#define rd_ctz(n) __cnttz4(n) -#define rd_ctz64(n) __cnttz8(n) - -#elif defined(__SUNPRO_C) // Solaris Studio compiler on sun -/* - * Source for following definitions is Hacker’s Delight, Second Edition by Henry S. Warren - * http://www.hackersdelight.org/permissions.htm - */ -u32 rd_clz(u32 x) { - u32 n; - - if (x == 0) return(32); - n = 1; - if ((x >> 16) == 0) {n = n +16; x = x <<16;} - if ((x >> 24) == 0) {n = n + 8; x = x << 8;} - if ((x >> 28) == 0) {n = n + 4; x = x << 4;} - if ((x >> 30) == 0) {n = n + 2; x = x << 2;} - n = n - (x >> 31); - return n; -} - -u32 rd_ctz(u32 x) { - u32 y; - u32 n; - - if (x == 0) return 32; - n = 31; - y = x <<16; if (y != 0) {n = n -16; x = y;} - y = x << 8; if (y != 0) {n = n - 8; x = y;} - y = x << 4; if (y != 0) {n = n - 4; x = y;} - y = x << 2; if (y != 0) {n = n - 2; x = y;} - y = x << 1; if (y != 0) {n = n - 1;} - return n; -} - -u64 rd_ctz64(u64 x) { - u64 y; - u64 n; - - if (x == 0) return 64; - n = 63; - y = x <<32; if (y != 0) {n = n -32; x = y;} - y = x <<16; if (y != 0) {n = n -16; x = y;} - y = x << 8; if (y != 0) {n = n - 8; x = y;} - y = x << 4; if (y != 0) {n = n - 4; x = y;} - y = x << 2; if (y != 0) {n = n - 2; x = y;} - y = x << 1; if (y != 0) {n = n - 1;} - return n; -} -#elif !defined(_MSC_VER) -#define rd_clz(n) __builtin_clz(n) -#define rd_ctz(n) __builtin_ctz(n) -#define rd_ctz64(n) __builtin_ctzll(n) -#else -#include <intrin.h> -static int inline rd_clz(u32 x) { - int r = 0; - if (_BitScanForward(&r, x)) - return 31 - r; - else - return 32; -} - -static int inline rd_ctz(u32 x) { - int r = 0; - if (_BitScanForward(&r, x)) - return r; - else - return 32; -} - -static int inline rd_ctz64(u64 x) { -#ifdef _M_X64 - int r = 0; - if (_BitScanReverse64(&r, x)) - return r; - else - return 64; -#else - int r; - if ((r = rd_ctz(x & 0xffffffff)) < 32) - return r; - return 32 + rd_ctz(x >> 32); -#endif -} -#endif - - -static inline int log2_floor(u32 n) -{ - return n == 0 ? -1 : 31 ^ rd_clz(n); -} - -static inline RD_UNUSED int find_lsb_set_non_zero(u32 n) -{ - return rd_ctz(n); -} - -static inline RD_UNUSED int find_lsb_set_non_zero64(u64 n) -{ - return rd_ctz64(n); -} - -#define kmax32 5 - -/* - * Attempts to parse a varint32 from a prefix of the bytes in [ptr,limit-1]. - * Never reads a character at or beyond limit. If a valid/terminated varint32 - * was found in the range, stores it in *OUTPUT and returns a pointer just - * past the last byte of the varint32. Else returns NULL. On success, - * "result <= limit". - */ -static inline const char *varint_parse32_with_limit(const char *p, - const char *l, - u32 * OUTPUT) -{ - const unsigned char *ptr = (const unsigned char *)(p); - const unsigned char *limit = (const unsigned char *)(l); - u32 b, result; - - if (ptr >= limit) - return NULL; - b = *(ptr++); - result = b & 127; - if (b < 128) - goto done; - if (ptr >= limit) - return NULL; - b = *(ptr++); - result |= (b & 127) << 7; - if (b < 128) - goto done; - if (ptr >= limit) - return NULL; - b = *(ptr++); - result |= (b & 127) << 14; - if (b < 128) - goto done; - if (ptr >= limit) - return NULL; - b = *(ptr++); - result |= (b & 127) << 21; - if (b < 128) - goto done; - if (ptr >= limit) - return NULL; - b = *(ptr++); - result |= (b & 127) << 28; - if (b < 16) - goto done; - return NULL; /* Value is too long to be a varint32 */ -done: - *OUTPUT = result; - return (const char *)(ptr); -} - -/* - * REQUIRES "ptr" points to a buffer of length sufficient to hold "v". - * EFFECTS Encodes "v" into "ptr" and returns a pointer to the - * byte just past the last encoded byte. - */ -static inline char *varint_encode32(char *sptr, u32 v) -{ - /* Operate on characters as unsigneds */ - unsigned char *ptr = (unsigned char *)(sptr); - static const int B = 128; - - if (v < (1 << 7)) { - *(ptr++) = v; - } else if (v < (1 << 14)) { - *(ptr++) = v | B; - *(ptr++) = v >> 7; - } else if (v < (1 << 21)) { - *(ptr++) = v | B; - *(ptr++) = (v >> 7) | B; - *(ptr++) = v >> 14; - } else if (v < (1 << 28)) { - *(ptr++) = v | B; - *(ptr++) = (v >> 7) | B; - *(ptr++) = (v >> 14) | B; - *(ptr++) = v >> 21; - } else { - *(ptr++) = v | B; - *(ptr++) = (v >> 7) | B; - *(ptr++) = (v >> 14) | B; - *(ptr++) = (v >> 21) | B; - *(ptr++) = v >> 28; - } - return (char *)(ptr); -} - -#ifdef SG - -static inline void *n_bytes_after_addr(void *addr, size_t n_bytes) -{ - return (void *) ((char *)addr + n_bytes); -} - -struct source { - struct iovec *iov; - int iovlen; - int curvec; - int curoff; - size_t total; -}; - -/* Only valid at beginning when nothing is consumed */ -static inline int available(struct source *s) -{ - return (int) s->total; -} - -static inline const char *peek(struct source *s, size_t *len) -{ - if (likely(s->curvec < s->iovlen)) { - struct iovec *iv = &s->iov[s->curvec]; - if ((unsigned)s->curoff < (size_t)iv->iov_len) { - *len = iv->iov_len - s->curoff; - return n_bytes_after_addr(iv->iov_base, s->curoff); - } - } - *len = 0; - return NULL; -} - -static inline void skip(struct source *s, size_t n) -{ - struct iovec *iv = &s->iov[s->curvec]; - s->curoff += (int) n; - DCHECK_LE((unsigned)s->curoff, (size_t)iv->iov_len); - if ((unsigned)s->curoff >= (size_t)iv->iov_len && - s->curvec + 1 < s->iovlen) { - s->curoff = 0; - s->curvec++; - } -} - -struct sink { - struct iovec *iov; - int iovlen; - unsigned curvec; - unsigned curoff; - unsigned written; -}; - -static inline void append(struct sink *s, const char *data, size_t n) -{ - struct iovec *iov = &s->iov[s->curvec]; - char *dst = n_bytes_after_addr(iov->iov_base, s->curoff); - size_t nlen = min_t(size_t, iov->iov_len - s->curoff, n); - if (data != dst) - memcpy(dst, data, nlen); - s->written += (int) n; - s->curoff += (int) nlen; - while ((n -= nlen) > 0) { - data += nlen; - s->curvec++; - DCHECK_LT((signed)s->curvec, s->iovlen); - iov++; - nlen = min_t(size_t, (size_t)iov->iov_len, n); - memcpy(iov->iov_base, data, nlen); - s->curoff = (int) nlen; - } -} - -static inline void *sink_peek(struct sink *s, size_t n) -{ - struct iovec *iov = &s->iov[s->curvec]; - if (s->curvec < (size_t)iov->iov_len && iov->iov_len - s->curoff >= n) - return n_bytes_after_addr(iov->iov_base, s->curoff); - return NULL; -} - -#else - -struct source { - const char *ptr; - size_t left; -}; - -static inline int available(struct source *s) -{ - return s->left; -} - -static inline const char *peek(struct source *s, size_t * len) -{ - *len = s->left; - return s->ptr; -} - -static inline void skip(struct source *s, size_t n) -{ - s->left -= n; - s->ptr += n; -} - -struct sink { - char *dest; -}; - -static inline void append(struct sink *s, const char *data, size_t n) -{ - if (data != s->dest) - memcpy(s->dest, data, n); - s->dest += n; -} - -#define sink_peek(s, n) sink_peek_no_sg(s) - -static inline void *sink_peek_no_sg(const struct sink *s) -{ - return s->dest; -} - -#endif - -struct writer { - char *base; - char *op; - char *op_limit; -}; - -/* Called before decompression */ -static inline void writer_set_expected_length(struct writer *w, size_t len) -{ - w->op_limit = w->op + len; -} - -/* Called after decompression */ -static inline bool writer_check_length(struct writer *w) -{ - return w->op == w->op_limit; -} - -/* - * Copy "len" bytes from "src" to "op", one byte at a time. Used for - * handling COPY operations where the input and output regions may - * overlap. For example, suppose: - * src == "ab" - * op == src + 2 - * len == 20 - * After IncrementalCopy(src, op, len), the result will have - * eleven copies of "ab" - * ababababababababababab - * Note that this does not match the semantics of either memcpy() - * or memmove(). - */ -static inline void incremental_copy(const char *src, char *op, ssize_t len) -{ - DCHECK_GT(len, 0); - do { - *op++ = *src++; - } while (--len > 0); -} - -/* - * Equivalent to IncrementalCopy except that it can write up to ten extra - * bytes after the end of the copy, and that it is faster. - * - * The main part of this loop is a simple copy of eight bytes at a time until - * we've copied (at least) the requested amount of bytes. However, if op and - * src are less than eight bytes apart (indicating a repeating pattern of - * length < 8), we first need to expand the pattern in order to get the correct - * results. For instance, if the buffer looks like this, with the eight-byte - * <src> and <op> patterns marked as intervals: - * - * abxxxxxxxxxxxx - * [------] src - * [------] op - * - * a single eight-byte copy from <src> to <op> will repeat the pattern once, - * after which we can move <op> two bytes without moving <src>: - * - * ababxxxxxxxxxx - * [------] src - * [------] op - * - * and repeat the exercise until the two no longer overlap. - * - * This allows us to do very well in the special case of one single byte - * repeated many times, without taking a big hit for more general cases. - * - * The worst case of extra writing past the end of the match occurs when - * op - src == 1 and len == 1; the last copy will read from byte positions - * [0..7] and write to [4..11], whereas it was only supposed to write to - * position 1. Thus, ten excess bytes. - */ - -#define kmax_increment_copy_overflow 10 - -static inline void incremental_copy_fast_path(const char *src, char *op, - ssize_t len) -{ - while (op - src < 8) { - unaligned_copy64(src, op); - len -= op - src; - op += op - src; - } - while (len > 0) { - unaligned_copy64(src, op); - src += 8; - op += 8; - len -= 8; - } -} - -static inline bool writer_append_from_self(struct writer *w, u32 offset, - u32 len) -{ - char *const op = w->op; - CHECK_LE(op, w->op_limit); - const u32 space_left = (u32) (w->op_limit - op); - - if ((unsigned)(op - w->base) <= offset - 1u) /* -1u catches offset==0 */ - return false; - if (len <= 16 && offset >= 8 && space_left >= 16) { - /* Fast path, used for the majority (70-80%) of dynamic - * invocations. */ - unaligned_copy64(op - offset, op); - unaligned_copy64(op - offset + 8, op + 8); - } else { - if (space_left >= len + kmax_increment_copy_overflow) { - incremental_copy_fast_path(op - offset, op, len); - } else { - if (space_left < len) { - return false; - } - incremental_copy(op - offset, op, len); - } - } - - w->op = op + len; - return true; -} - -static inline bool writer_append(struct writer *w, const char *ip, u32 len) -{ - char *const op = w->op; - CHECK_LE(op, w->op_limit); - const u32 space_left = (u32) (w->op_limit - op); - if (space_left < len) - return false; - memcpy(op, ip, len); - w->op = op + len; - return true; -} - -static inline bool writer_try_fast_append(struct writer *w, const char *ip, - u32 available_bytes, u32 len) -{ - char *const op = w->op; - const int space_left = (int) (w->op_limit - op); - if (len <= 16 && available_bytes >= 16 && space_left >= 16) { - /* Fast path, used for the majority (~95%) of invocations */ - unaligned_copy64(ip, op); - unaligned_copy64(ip + 8, op + 8); - w->op = op + len; - return true; - } - return false; -} - -/* - * Any hash function will produce a valid compressed bitstream, but a good - * hash function reduces the number of collisions and thus yields better - * compression for compressible input, and more speed for incompressible - * input. Of course, it doesn't hurt if the hash function is reasonably fast - * either, as it gets called a lot. - */ -static inline u32 hash_bytes(u32 bytes, int shift) -{ - u32 kmul = 0x1e35a7bd; - return (bytes * kmul) >> shift; -} - -static inline u32 hash(const char *p, int shift) -{ - return hash_bytes(UNALIGNED_LOAD32(p), shift); -} - -/* - * Compressed data can be defined as: - * compressed := item* literal* - * item := literal* copy - * - * The trailing literal sequence has a space blowup of at most 62/60 - * since a literal of length 60 needs one tag byte + one extra byte - * for length information. - * - * Item blowup is trickier to measure. Suppose the "copy" op copies - * 4 bytes of data. Because of a special check in the encoding code, - * we produce a 4-byte copy only if the offset is < 65536. Therefore - * the copy op takes 3 bytes to encode, and this type of item leads - * to at most the 62/60 blowup for representing literals. - * - * Suppose the "copy" op copies 5 bytes of data. If the offset is big - * enough, it will take 5 bytes to encode the copy op. Therefore the - * worst case here is a one-byte literal followed by a five-byte copy. - * I.e., 6 bytes of input turn into 7 bytes of "compressed" data. - * - * This last factor dominates the blowup, so the final estimate is: - */ -size_t rd_kafka_snappy_max_compressed_length(size_t source_len) -{ - return 32 + source_len + source_len / 6; -} -EXPORT_SYMBOL(rd_kafka_snappy_max_compressed_length); - -enum { - LITERAL = 0, - COPY_1_BYTE_OFFSET = 1, /* 3 bit length + 3 bits of offset in opcode */ - COPY_2_BYTE_OFFSET = 2, - COPY_4_BYTE_OFFSET = 3 -}; - -static inline char *emit_literal(char *op, - const char *literal, - int len, bool allow_fast_path) -{ - int n = len - 1; /* Zero-length literals are disallowed */ - - if (n < 60) { - /* Fits in tag byte */ - *op++ = LITERAL | (n << 2); - -/* - * The vast majority of copies are below 16 bytes, for which a - * call to memcpy is overkill. This fast path can sometimes - * copy up to 15 bytes too much, but that is okay in the - * main loop, since we have a bit to go on for both sides: - * - * - The input will always have kInputMarginBytes = 15 extra - * available bytes, as long as we're in the main loop, and - * if not, allow_fast_path = false. - * - The output will always have 32 spare bytes (see - * MaxCompressedLength). - */ - if (allow_fast_path && len <= 16) { - unaligned_copy64(literal, op); - unaligned_copy64(literal + 8, op + 8); - return op + len; - } - } else { - /* Encode in upcoming bytes */ - char *base = op; - int count = 0; - op++; - while (n > 0) { - *op++ = n & 0xff; - n >>= 8; - count++; - } - DCHECK(count >= 1); - DCHECK(count <= 4); - *base = LITERAL | ((59 + count) << 2); - } - memcpy(op, literal, len); - return op + len; -} - -static inline char *emit_copy_less_than64(char *op, int offset, int len) -{ - DCHECK_LE(len, 64); - DCHECK_GE(len, 4); - DCHECK_LT(offset, 65536); - - if ((len < 12) && (offset < 2048)) { - int len_minus_4 = len - 4; - DCHECK(len_minus_4 < 8); /* Must fit in 3 bits */ - *op++ = - COPY_1_BYTE_OFFSET + ((len_minus_4) << 2) + ((offset >> 8) - << 5); - *op++ = offset & 0xff; - } else { - *op++ = COPY_2_BYTE_OFFSET + ((len - 1) << 2); - put_unaligned_le16(offset, op); - op += 2; - } - return op; -} - -static inline char *emit_copy(char *op, int offset, int len) -{ - /* - * Emit 64 byte copies but make sure to keep at least four bytes - * reserved - */ - while (len >= 68) { - op = emit_copy_less_than64(op, offset, 64); - len -= 64; - } - - /* - * Emit an extra 60 byte copy if have too much data to fit in - * one copy - */ - if (len > 64) { - op = emit_copy_less_than64(op, offset, 60); - len -= 60; - } - - /* Emit remainder */ - op = emit_copy_less_than64(op, offset, len); - return op; -} - -/** - * rd_kafka_snappy_uncompressed_length - return length of uncompressed output. - * @start: compressed buffer - * @n: length of compressed buffer. - * @result: Write the length of the uncompressed output here. - * - * Returns true when successfull, otherwise false. - */ -bool rd_kafka_snappy_uncompressed_length(const char *start, size_t n, size_t * result) -{ - u32 v = 0; - const char *limit = start + n; - if (varint_parse32_with_limit(start, limit, &v) != NULL) { - *result = v; - return true; - } else { - return false; - } -} -EXPORT_SYMBOL(rd_kafka_snappy_uncompressed_length); - -/* - * The size of a compression block. Note that many parts of the compression - * code assumes that kBlockSize <= 65536; in particular, the hash table - * can only store 16-bit offsets, and EmitCopy() also assumes the offset - * is 65535 bytes or less. Note also that if you change this, it will - * affect the framing format - * Note that there might be older data around that is compressed with larger - * block sizes, so the decompression code should not rely on the - * non-existence of long backreferences. - */ -#define kblock_log 16 -#define kblock_size (1 << kblock_log) - -/* - * This value could be halfed or quartered to save memory - * at the cost of slightly worse compression. - */ -#define kmax_hash_table_bits 14 -#define kmax_hash_table_size (1U << kmax_hash_table_bits) - -/* - * Use smaller hash table when input.size() is smaller, since we - * fill the table, incurring O(hash table size) overhead for - * compression, and if the input is short, we won't need that - * many hash table entries anyway. - */ -static u16 *get_hash_table(struct snappy_env *env, size_t input_size, - int *table_size) -{ - unsigned htsize = 256; - - DCHECK(kmax_hash_table_size >= 256); - while (htsize < kmax_hash_table_size && htsize < input_size) - htsize <<= 1; - CHECK_EQ(0, htsize & (htsize - 1)); - CHECK_LE(htsize, kmax_hash_table_size); - - u16 *table; - table = env->hash_table; - - *table_size = htsize; - memset(table, 0, htsize * sizeof(*table)); - return table; -} - -/* - * Return the largest n such that - * - * s1[0,n-1] == s2[0,n-1] - * and n <= (s2_limit - s2). - * - * Does not read *s2_limit or beyond. - * Does not read *(s1 + (s2_limit - s2)) or beyond. - * Requires that s2_limit >= s2. - * - * Separate implementation for x86_64, for speed. Uses the fact that - * x86_64 is little endian. - */ -#if defined(__LITTLE_ENDIAN__) && BITS_PER_LONG == 64 -static inline int find_match_length(const char *s1, - const char *s2, const char *s2_limit) -{ - int matched = 0; - - DCHECK_GE(s2_limit, s2); - /* - * Find out how long the match is. We loop over the data 64 bits at a - * time until we find a 64-bit block that doesn't match; then we find - * the first non-matching bit and use that to calculate the total - * length of the match. - */ - while (likely(s2 <= s2_limit - 8)) { - if (unlikely - (UNALIGNED_LOAD64(s2) == UNALIGNED_LOAD64(s1 + matched))) { - s2 += 8; - matched += 8; - } else { - /* - * On current (mid-2008) Opteron models there - * is a 3% more efficient code sequence to - * find the first non-matching byte. However, - * what follows is ~10% better on Intel Core 2 - * and newer, and we expect AMD's bsf - * instruction to improve. - */ - u64 x = - UNALIGNED_LOAD64(s2) ^ UNALIGNED_LOAD64(s1 + - matched); - int matching_bits = find_lsb_set_non_zero64(x); - matched += matching_bits >> 3; - return matched; - } - } - while (likely(s2 < s2_limit)) { - if (likely(s1[matched] == *s2)) { - ++s2; - ++matched; - } else { - return matched; - } - } - return matched; -} -#else -static inline int find_match_length(const char *s1, - const char *s2, const char *s2_limit) -{ - /* Implementation based on the x86-64 version, above. */ - DCHECK_GE(s2_limit, s2); - int matched = 0; - - while (s2 <= s2_limit - 4 && - UNALIGNED_LOAD32(s2) == UNALIGNED_LOAD32(s1 + matched)) { - s2 += 4; - matched += 4; - } - if (is_little_endian() && s2 <= s2_limit - 4) { - u32 x = - UNALIGNED_LOAD32(s2) ^ UNALIGNED_LOAD32(s1 + matched); - int matching_bits = find_lsb_set_non_zero(x); - matched += matching_bits >> 3; - } else { - while ((s2 < s2_limit) && (s1[matched] == *s2)) { - ++s2; - ++matched; - } - } - return matched; -} -#endif - -/* - * For 0 <= offset <= 4, GetU32AtOffset(GetEightBytesAt(p), offset) will - * equal UNALIGNED_LOAD32(p + offset). Motivation: On x86-64 hardware we have - * empirically found that overlapping loads such as - * UNALIGNED_LOAD32(p) ... UNALIGNED_LOAD32(p+1) ... UNALIGNED_LOAD32(p+2) - * are slower than UNALIGNED_LOAD64(p) followed by shifts and casts to u32. - * - * We have different versions for 64- and 32-bit; ideally we would avoid the - * two functions and just inline the UNALIGNED_LOAD64 call into - * GetUint32AtOffset, but GCC (at least not as of 4.6) is seemingly not clever - * enough to avoid loading the value multiple times then. For 64-bit, the load - * is done when GetEightBytesAt() is called, whereas for 32-bit, the load is - * done at GetUint32AtOffset() time. - */ - -#if BITS_PER_LONG == 64 - -typedef u64 eight_bytes_reference; - -static inline eight_bytes_reference get_eight_bytes_at(const char* ptr) -{ - return UNALIGNED_LOAD64(ptr); -} - -static inline u32 get_u32_at_offset(u64 v, int offset) -{ - DCHECK_GE(offset, 0); - DCHECK_LE(offset, 4); - return v >> (is_little_endian()? 8 * offset : 32 - 8 * offset); -} - -#else - -typedef const char *eight_bytes_reference; - -static inline eight_bytes_reference get_eight_bytes_at(const char* ptr) -{ - return ptr; -} - -static inline u32 get_u32_at_offset(const char *v, int offset) -{ - DCHECK_GE(offset, 0); - DCHECK_LE(offset, 4); - return UNALIGNED_LOAD32(v + offset); -} -#endif - -/* - * Flat array compression that does not emit the "uncompressed length" - * prefix. Compresses "input" string to the "*op" buffer. - * - * REQUIRES: "input" is at most "kBlockSize" bytes long. - * REQUIRES: "op" points to an array of memory that is at least - * "MaxCompressedLength(input.size())" in size. - * REQUIRES: All elements in "table[0..table_size-1]" are initialized to zero. - * REQUIRES: "table_size" is a power of two - * - * Returns an "end" pointer into "op" buffer. - * "end - op" is the compressed size of "input". - */ - -static char *compress_fragment(const char *const input, - const size_t input_size, - char *op, u16 * table, const unsigned table_size) -{ - /* "ip" is the input pointer, and "op" is the output pointer. */ - const char *ip = input; - CHECK_LE(input_size, kblock_size); - CHECK_EQ(table_size & (table_size - 1), 0); - const int shift = 32 - log2_floor(table_size); - DCHECK_EQ(UINT_MAX >> shift, table_size - 1); - const char *ip_end = input + input_size; - const char *baseip = ip; - /* - * Bytes in [next_emit, ip) will be emitted as literal bytes. Or - * [next_emit, ip_end) after the main loop. - */ - const char *next_emit = ip; - - const unsigned kinput_margin_bytes = 15; - - if (likely(input_size >= kinput_margin_bytes)) { - const char *const ip_limit = input + input_size - - kinput_margin_bytes; - - u32 next_hash; - for (next_hash = hash(++ip, shift);;) { - DCHECK_LT(next_emit, ip); -/* - * The body of this loop calls EmitLiteral once and then EmitCopy one or - * more times. (The exception is that when we're close to exhausting - * the input we goto emit_remainder.) - * - * In the first iteration of this loop we're just starting, so - * there's nothing to copy, so calling EmitLiteral once is - * necessary. And we only start a new iteration when the - * current iteration has determined that a call to EmitLiteral will - * precede the next call to EmitCopy (if any). - * - * Step 1: Scan forward in the input looking for a 4-byte-long match. - * If we get close to exhausting the input then goto emit_remainder. - * - * Heuristic match skipping: If 32 bytes are scanned with no matches - * found, start looking only at every other byte. If 32 more bytes are - * scanned, look at every third byte, etc.. When a match is found, - * immediately go back to looking at every byte. This is a small loss - * (~5% performance, ~0.1% density) for lcompressible data due to more - * bookkeeping, but for non-compressible data (such as JPEG) it's a huge - * win since the compressor quickly "realizes" the data is incompressible - * and doesn't bother looking for matches everywhere. - * - * The "skip" variable keeps track of how many bytes there are since the - * last match; dividing it by 32 (ie. right-shifting by five) gives the - * number of bytes to move ahead for each iteration. - */ - u32 skip_bytes = 32; - - const char *next_ip = ip; - const char *candidate; - do { - ip = next_ip; - u32 hval = next_hash; - DCHECK_EQ(hval, hash(ip, shift)); - u32 bytes_between_hash_lookups = skip_bytes++ >> 5; - next_ip = ip + bytes_between_hash_lookups; - if (unlikely(next_ip > ip_limit)) { - goto emit_remainder; - } - next_hash = hash(next_ip, shift); - candidate = baseip + table[hval]; - DCHECK_GE(candidate, baseip); - DCHECK_LT(candidate, ip); - - table[hval] = (u16) (ip - baseip); - } while (likely(UNALIGNED_LOAD32(ip) != - UNALIGNED_LOAD32(candidate))); - -/* - * Step 2: A 4-byte match has been found. We'll later see if more - * than 4 bytes match. But, prior to the match, input - * bytes [next_emit, ip) are unmatched. Emit them as "literal bytes." - */ - DCHECK_LE(next_emit + 16, ip_end); - op = emit_literal(op, next_emit, (int) (ip - next_emit), true); - -/* - * Step 3: Call EmitCopy, and then see if another EmitCopy could - * be our next move. Repeat until we find no match for the - * input immediately after what was consumed by the last EmitCopy call. - * - * If we exit this loop normally then we need to call EmitLiteral next, - * though we don't yet know how big the literal will be. We handle that - * by proceeding to the next iteration of the main loop. We also can exit - * this loop via goto if we get close to exhausting the input. - */ - eight_bytes_reference input_bytes; - u32 candidate_bytes = 0; - - do { -/* - * We have a 4-byte match at ip, and no need to emit any - * "literal bytes" prior to ip. - */ - const char *base = ip; - int matched = 4 + - find_match_length(candidate + 4, ip + 4, - ip_end); - ip += matched; - int offset = (int) (base - candidate); - DCHECK_EQ(0, memcmp(base, candidate, matched)); - op = emit_copy(op, offset, matched); -/* - * We could immediately start working at ip now, but to improve - * compression we first update table[Hash(ip - 1, ...)]. - */ - const char *insert_tail = ip - 1; - next_emit = ip; - if (unlikely(ip >= ip_limit)) { - goto emit_remainder; - } - input_bytes = get_eight_bytes_at(insert_tail); - u32 prev_hash = - hash_bytes(get_u32_at_offset - (input_bytes, 0), shift); - table[prev_hash] = (u16) (ip - baseip - 1); - u32 cur_hash = - hash_bytes(get_u32_at_offset - (input_bytes, 1), shift); - candidate = baseip + table[cur_hash]; - candidate_bytes = UNALIGNED_LOAD32(candidate); - table[cur_hash] = (u16) (ip - baseip); - } while (get_u32_at_offset(input_bytes, 1) == - candidate_bytes); - - next_hash = - hash_bytes(get_u32_at_offset(input_bytes, 2), - shift); - ++ip; - } - } - -emit_remainder: - /* Emit the remaining bytes as a literal */ - if (next_emit < ip_end) - op = emit_literal(op, next_emit, (int) (ip_end - next_emit), false); - - return op; -} - -/* - * ----------------------------------------------------------------------- - * Lookup table for decompression code. Generated by ComputeTable() below. - * ----------------------------------------------------------------------- - */ - -/* Mapping from i in range [0,4] to a mask to extract the bottom 8*i bits */ -static const u32 wordmask[] = { - 0u, 0xffu, 0xffffu, 0xffffffu, 0xffffffffu -}; - -/* - * Data stored per entry in lookup table: - * Range Bits-used Description - * ------------------------------------ - * 1..64 0..7 Literal/copy length encoded in opcode byte - * 0..7 8..10 Copy offset encoded in opcode byte / 256 - * 0..4 11..13 Extra bytes after opcode - * - * We use eight bits for the length even though 7 would have sufficed - * because of efficiency reasons: - * (1) Extracting a byte is faster than a bit-field - * (2) It properly aligns copy offset so we do not need a <<8 - */ -static const u16 char_table[256] = { - 0x0001, 0x0804, 0x1001, 0x2001, 0x0002, 0x0805, 0x1002, 0x2002, - 0x0003, 0x0806, 0x1003, 0x2003, 0x0004, 0x0807, 0x1004, 0x2004, - 0x0005, 0x0808, 0x1005, 0x2005, 0x0006, 0x0809, 0x1006, 0x2006, - 0x0007, 0x080a, 0x1007, 0x2007, 0x0008, 0x080b, 0x1008, 0x2008, - 0x0009, 0x0904, 0x1009, 0x2009, 0x000a, 0x0905, 0x100a, 0x200a, - 0x000b, 0x0906, 0x100b, 0x200b, 0x000c, 0x0907, 0x100c, 0x200c, - 0x000d, 0x0908, 0x100d, 0x200d, 0x000e, 0x0909, 0x100e, 0x200e, - 0x000f, 0x090a, 0x100f, 0x200f, 0x0010, 0x090b, 0x1010, 0x2010, - 0x0011, 0x0a04, 0x1011, 0x2011, 0x0012, 0x0a05, 0x1012, 0x2012, - 0x0013, 0x0a06, 0x1013, 0x2013, 0x0014, 0x0a07, 0x1014, 0x2014, - 0x0015, 0x0a08, 0x1015, 0x2015, 0x0016, 0x0a09, 0x1016, 0x2016, - 0x0017, 0x0a0a, 0x1017, 0x2017, 0x0018, 0x0a0b, 0x1018, 0x2018, - 0x0019, 0x0b04, 0x1019, 0x2019, 0x001a, 0x0b05, 0x101a, 0x201a, - 0x001b, 0x0b06, 0x101b, 0x201b, 0x001c, 0x0b07, 0x101c, 0x201c, - 0x001d, 0x0b08, 0x101d, 0x201d, 0x001e, 0x0b09, 0x101e, 0x201e, - 0x001f, 0x0b0a, 0x101f, 0x201f, 0x0020, 0x0b0b, 0x1020, 0x2020, - 0x0021, 0x0c04, 0x1021, 0x2021, 0x0022, 0x0c05, 0x1022, 0x2022, - 0x0023, 0x0c06, 0x1023, 0x2023, 0x0024, 0x0c07, 0x1024, 0x2024, - 0x0025, 0x0c08, 0x1025, 0x2025, 0x0026, 0x0c09, 0x1026, 0x2026, - 0x0027, 0x0c0a, 0x1027, 0x2027, 0x0028, 0x0c0b, 0x1028, 0x2028, - 0x0029, 0x0d04, 0x1029, 0x2029, 0x002a, 0x0d05, 0x102a, 0x202a, - 0x002b, 0x0d06, 0x102b, 0x202b, 0x002c, 0x0d07, 0x102c, 0x202c, - 0x002d, 0x0d08, 0x102d, 0x202d, 0x002e, 0x0d09, 0x102e, 0x202e, - 0x002f, 0x0d0a, 0x102f, 0x202f, 0x0030, 0x0d0b, 0x1030, 0x2030, - 0x0031, 0x0e04, 0x1031, 0x2031, 0x0032, 0x0e05, 0x1032, 0x2032, - 0x0033, 0x0e06, 0x1033, 0x2033, 0x0034, 0x0e07, 0x1034, 0x2034, - 0x0035, 0x0e08, 0x1035, 0x2035, 0x0036, 0x0e09, 0x1036, 0x2036, - 0x0037, 0x0e0a, 0x1037, 0x2037, 0x0038, 0x0e0b, 0x1038, 0x2038, - 0x0039, 0x0f04, 0x1039, 0x2039, 0x003a, 0x0f05, 0x103a, 0x203a, - 0x003b, 0x0f06, 0x103b, 0x203b, 0x003c, 0x0f07, 0x103c, 0x203c, - 0x0801, 0x0f08, 0x103d, 0x203d, 0x1001, 0x0f09, 0x103e, 0x203e, - 0x1801, 0x0f0a, 0x103f, 0x203f, 0x2001, 0x0f0b, 0x1040, 0x2040 -}; - -struct snappy_decompressor { - struct source *reader; /* Underlying source of bytes to decompress */ - const char *ip; /* Points to next buffered byte */ - const char *ip_limit; /* Points just past buffered bytes */ - u32 peeked; /* Bytes peeked from reader (need to skip) */ - bool eof; /* Hit end of input without an error? */ - char scratch[5]; /* Temporary buffer for peekfast boundaries */ -}; - -static void -init_snappy_decompressor(struct snappy_decompressor *d, struct source *reader) -{ - d->reader = reader; - d->ip = NULL; - d->ip_limit = NULL; - d->peeked = 0; - d->eof = false; -} - -static void exit_snappy_decompressor(struct snappy_decompressor *d) -{ - skip(d->reader, d->peeked); -} - -/* - * Read the uncompressed length stored at the start of the compressed data. - * On succcess, stores the length in *result and returns true. - * On failure, returns false. - */ -static bool read_uncompressed_length(struct snappy_decompressor *d, - u32 * result) -{ - DCHECK(d->ip == NULL); /* - * Must not have read anything yet - * Length is encoded in 1..5 bytes - */ - *result = 0; - u32 shift = 0; - while (true) { - if (shift >= 32) - return false; - size_t n; - const char *ip = peek(d->reader, &n); - if (n == 0) - return false; - const unsigned char c = *(const unsigned char *)(ip); - skip(d->reader, 1); - *result |= (u32) (c & 0x7f) << shift; - if (c < 128) { - break; - } - shift += 7; - } - return true; -} - -static bool refill_tag(struct snappy_decompressor *d); - -/* - * Process the next item found in the input. - * Returns true if successful, false on error or end of input. - */ -static void decompress_all_tags(struct snappy_decompressor *d, - struct writer *writer) -{ - const char *ip = d->ip; - - /* - * We could have put this refill fragment only at the beginning of the loop. - * However, duplicating it at the end of each branch gives the compiler more - * scope to optimize the <ip_limit_ - ip> expression based on the local - * context, which overall increases speed. - */ -#define MAYBE_REFILL() \ - if (d->ip_limit - ip < 5) { \ - d->ip = ip; \ - if (!refill_tag(d)) return; \ - ip = d->ip; \ - } - - - MAYBE_REFILL(); - for (;;) { - if (d->ip_limit - ip < 5) { - d->ip = ip; - if (!refill_tag(d)) - return; - ip = d->ip; - } - - const unsigned char c = *(const unsigned char *)(ip++); - - if ((c & 0x3) == LITERAL) { - u32 literal_length = (c >> 2) + 1; - if (writer_try_fast_append(writer, ip, (u32) (d->ip_limit - ip), - literal_length)) { - DCHECK_LT(literal_length, 61); - ip += literal_length; - MAYBE_REFILL(); - continue; - } - if (unlikely(literal_length >= 61)) { - /* Long literal */ - const u32 literal_ll = literal_length - 60; - literal_length = (get_unaligned_le32(ip) & - wordmask[literal_ll]) + 1; - ip += literal_ll; - } - - u32 avail = (u32) (d->ip_limit - ip); - while (avail < literal_length) { - if (!writer_append(writer, ip, avail)) - return; - literal_length -= avail; - skip(d->reader, d->peeked); - size_t n; - ip = peek(d->reader, &n); - avail = (u32) n; - d->peeked = avail; - if (avail == 0) - return; /* Premature end of input */ - d->ip_limit = ip + avail; - } - if (!writer_append(writer, ip, literal_length)) - return; - ip += literal_length; - MAYBE_REFILL(); - } else { - const u32 entry = char_table[c]; - const u32 trailer = get_unaligned_le32(ip) & - wordmask[entry >> 11]; - const u32 length = entry & 0xff; - ip += entry >> 11; - - /* - * copy_offset/256 is encoded in bits 8..10. - * By just fetching those bits, we get - * copy_offset (since the bit-field starts at - * bit 8). - */ - const u32 copy_offset = entry & 0x700; - if (!writer_append_from_self(writer, - copy_offset + trailer, - length)) - return; - MAYBE_REFILL(); - } - } -} - -#undef MAYBE_REFILL - -static bool refill_tag(struct snappy_decompressor *d) -{ - const char *ip = d->ip; - - if (ip == d->ip_limit) { - size_t n; - /* Fetch a new fragment from the reader */ - skip(d->reader, d->peeked); /* All peeked bytes are used up */ - ip = peek(d->reader, &n); - d->peeked = (u32) n; - if (n == 0) { - d->eof = true; - return false; - } - d->ip_limit = ip + n; - } - - /* Read the tag character */ - DCHECK_LT(ip, d->ip_limit); - const unsigned char c = *(const unsigned char *)(ip); - const u32 entry = char_table[c]; - const u32 needed = (entry >> 11) + 1; /* +1 byte for 'c' */ - DCHECK_LE(needed, sizeof(d->scratch)); - - /* Read more bytes from reader if needed */ - u32 nbuf = (u32) (d->ip_limit - ip); - - if (nbuf < needed) { - /* - * Stitch together bytes from ip and reader to form the word - * contents. We store the needed bytes in "scratch". They - * will be consumed immediately by the caller since we do not - * read more than we need. - */ - memmove(d->scratch, ip, nbuf); - skip(d->reader, d->peeked); /* All peeked bytes are used up */ - d->peeked = 0; - while (nbuf < needed) { - size_t length; - const char *src = peek(d->reader, &length); - if (length == 0) - return false; - u32 to_add = min_t(u32, needed - nbuf, (u32) length); - memcpy(d->scratch + nbuf, src, to_add); - nbuf += to_add; - skip(d->reader, to_add); - } - DCHECK_EQ(nbuf, needed); - d->ip = d->scratch; - d->ip_limit = d->scratch + needed; - } else if (nbuf < 5) { - /* - * Have enough bytes, but move into scratch so that we do not - * read past end of input - */ - memmove(d->scratch, ip, nbuf); - skip(d->reader, d->peeked); /* All peeked bytes are used up */ - d->peeked = 0; - d->ip = d->scratch; - d->ip_limit = d->scratch + nbuf; - } else { - /* Pass pointer to buffer returned by reader. */ - d->ip = ip; - } - return true; -} - -static int internal_uncompress(struct source *r, - struct writer *writer, u32 max_len) -{ - struct snappy_decompressor decompressor; - u32 uncompressed_len = 0; - - init_snappy_decompressor(&decompressor, r); - - if (!read_uncompressed_length(&decompressor, &uncompressed_len)) - return -EIO; - /* Protect against possible DoS attack */ - if ((u64) (uncompressed_len) > max_len) - return -EIO; - - writer_set_expected_length(writer, uncompressed_len); - - /* Process the entire input */ - decompress_all_tags(&decompressor, writer); - - exit_snappy_decompressor(&decompressor); - if (decompressor.eof && writer_check_length(writer)) - return 0; - return -EIO; -} - -static inline int sn_compress(struct snappy_env *env, struct source *reader, - struct sink *writer) -{ - int err; - size_t written = 0; - int N = available(reader); - char ulength[kmax32]; - char *p = varint_encode32(ulength, N); - - append(writer, ulength, p - ulength); - written += (p - ulength); - - while (N > 0) { - /* Get next block to compress (without copying if possible) */ - size_t fragment_size; - const char *fragment = peek(reader, &fragment_size); - if (fragment_size == 0) { - err = -EIO; - goto out; - } - const unsigned num_to_read = min_t(int, N, kblock_size); - size_t bytes_read = fragment_size; - - int pending_advance = 0; - if (bytes_read >= num_to_read) { - /* Buffer returned by reader is large enough */ - pending_advance = num_to_read; - fragment_size = num_to_read; - } - else { - memcpy(env->scratch, fragment, bytes_read); - skip(reader, bytes_read); - - while (bytes_read < num_to_read) { - fragment = peek(reader, &fragment_size); - size_t n = - min_t(size_t, fragment_size, - num_to_read - bytes_read); - memcpy((char *)(env->scratch) + bytes_read, fragment, n); - bytes_read += n; - skip(reader, n); - } - DCHECK_EQ(bytes_read, num_to_read); - fragment = env->scratch; - fragment_size = num_to_read; - } - if (fragment_size < num_to_read) - return -EIO; - - /* Get encoding table for compression */ - int table_size; - u16 *table = get_hash_table(env, num_to_read, &table_size); - - /* Compress input_fragment and append to dest */ - char *dest; - dest = sink_peek(writer, rd_kafka_snappy_max_compressed_length(num_to_read)); - if (!dest) { - /* - * Need a scratch buffer for the output, - * because the byte sink doesn't have enough - * in one piece. - */ - dest = env->scratch_output; - } - char *end = compress_fragment(fragment, fragment_size, - dest, table, table_size); - append(writer, dest, end - dest); - written += (end - dest); - - N -= num_to_read; - skip(reader, pending_advance); - } - - err = 0; -out: - return err; -} - -#ifdef SG - -int rd_kafka_snappy_compress_iov(struct snappy_env *env, - const struct iovec *iov_in, size_t iov_in_cnt, - size_t input_length, - struct iovec *iov_out) { - struct source reader = { - .iov = (struct iovec *)iov_in, - .iovlen = (int)iov_in_cnt, - .total = input_length - }; - struct sink writer = { - .iov = iov_out, - .iovlen = 1 - }; - int err = sn_compress(env, &reader, &writer); - - iov_out->iov_len = writer.written; - - return err; -} -EXPORT_SYMBOL(rd_kafka_snappy_compress_iov); - -/** - * rd_kafka_snappy_compress - Compress a buffer using the snappy compressor. - * @env: Preallocated environment - * @input: Input buffer - * @input_length: Length of input_buffer - * @compressed: Output buffer for compressed data - * @compressed_length: The real length of the output written here. - * - * Return 0 on success, otherwise an negative error code. - * - * The output buffer must be at least - * rd_kafka_snappy_max_compressed_length(input_length) bytes long. - * - * Requires a preallocated environment from rd_kafka_snappy_init_env. - * The environment does not keep state over individual calls - * of this function, just preallocates the memory. - */ -int rd_kafka_snappy_compress(struct snappy_env *env, - const char *input, - size_t input_length, - char *compressed, size_t *compressed_length) -{ - struct iovec iov_in = { - .iov_base = (char *)input, - .iov_len = input_length, - }; - struct iovec iov_out = { - .iov_base = compressed, - .iov_len = 0xffffffff, - }; - return rd_kafka_snappy_compress_iov(env, - &iov_in, 1, input_length, - &iov_out); -} -EXPORT_SYMBOL(rd_kafka_snappy_compress); - -int rd_kafka_snappy_uncompress_iov(struct iovec *iov_in, int iov_in_len, - size_t input_len, char *uncompressed) -{ - struct source reader = { - .iov = iov_in, - .iovlen = iov_in_len, - .total = input_len - }; - struct writer output = { - .base = uncompressed, - .op = uncompressed - }; - return internal_uncompress(&reader, &output, 0xffffffff); -} -EXPORT_SYMBOL(rd_kafka_snappy_uncompress_iov); - -/** - * rd_kafka_snappy_uncompress - Uncompress a snappy compressed buffer - * @compressed: Input buffer with compressed data - * @n: length of compressed buffer - * @uncompressed: buffer for uncompressed data - * - * The uncompressed data buffer must be at least - * rd_kafka_snappy_uncompressed_length(compressed) bytes long. - * - * Return 0 on success, otherwise an negative error code. - */ -int rd_kafka_snappy_uncompress(const char *compressed, size_t n, char *uncompressed) -{ - struct iovec iov = { - .iov_base = (char *)compressed, - .iov_len = n - }; - return rd_kafka_snappy_uncompress_iov(&iov, 1, n, uncompressed); -} -EXPORT_SYMBOL(rd_kafka_snappy_uncompress); - - -/** - * @brief Decompress Snappy message with Snappy-java framing. - * - * @returns a malloced buffer with the uncompressed data, or NULL on failure. - */ -char *rd_kafka_snappy_java_uncompress (const char *inbuf, size_t inlen, - size_t *outlenp, - char *errstr, size_t errstr_size) { - int pass; - char *outbuf = NULL; - - /** - * Traverse all chunks in two passes: - * pass 1: calculate total uncompressed length - * pass 2: uncompress - * - * Each chunk is prefixed with 4: length */ - - for (pass = 1 ; pass <= 2 ; pass++) { - ssize_t of = 0; /* inbuf offset */ - ssize_t uof = 0; /* outbuf offset */ - - while (of + 4 <= (ssize_t)inlen) { - uint32_t clen; /* compressed length */ - size_t ulen; /* uncompressed length */ - int r; - - memcpy(&clen, inbuf+of, 4); - clen = be32toh(clen); - of += 4; - - if (unlikely(clen > inlen - of)) { - rd_snprintf(errstr, errstr_size, - "Invalid snappy-java chunk length " - "%"PRId32" > %"PRIdsz - " available bytes", - clen, (ssize_t)inlen - of); - return NULL; - } - - /* Acquire uncompressed length */ - if (unlikely(!rd_kafka_snappy_uncompressed_length( - inbuf+of, clen, &ulen))) { - rd_snprintf(errstr, errstr_size, - "Failed to get length of " - "(snappy-java framed) Snappy " - "compressed payload " - "(clen %"PRId32")", - clen); - return NULL; - } - - if (pass == 1) { - /* pass 1: calculate total length */ - of += clen; - uof += ulen; - continue; - } - - /* pass 2: Uncompress to outbuf */ - if (unlikely((r = rd_kafka_snappy_uncompress( - inbuf+of, clen, outbuf+uof)))) { - rd_snprintf(errstr, errstr_size, - "Failed to decompress Snappy-java " - "framed payload of size %"PRId32 - ": %s", - clen, - rd_strerror(-r/*negative errno*/)); - rd_free(outbuf); - return NULL; - } - - of += clen; - uof += ulen; - } - - if (unlikely(of != (ssize_t)inlen)) { - rd_snprintf(errstr, errstr_size, - "%"PRIusz" trailing bytes in Snappy-java " - "framed compressed data", - inlen - of); - if (outbuf) - rd_free(outbuf); - return NULL; - } - - if (pass == 1) { - if (uof <= 0) { - rd_snprintf(errstr, errstr_size, - "Empty Snappy-java framed data"); - return NULL; - } - - /* Allocate memory for uncompressed data */ - outbuf = rd_malloc(uof); - if (unlikely(!outbuf)) { - rd_snprintf(errstr, errstr_size, - "Failed to allocate memory " - "(%"PRIdsz") for " - "uncompressed Snappy data: %s", - uof, rd_strerror(errno)); - return NULL; - } - - } else { - /* pass 2 */ - *outlenp = uof; - } - } - - return outbuf; -} - - - -#else -/** - * rd_kafka_snappy_compress - Compress a buffer using the snappy compressor. - * @env: Preallocated environment - * @input: Input buffer - * @input_length: Length of input_buffer - * @compressed: Output buffer for compressed data - * @compressed_length: The real length of the output written here. - * - * Return 0 on success, otherwise an negative error code. - * - * The output buffer must be at least - * rd_kafka_snappy_max_compressed_length(input_length) bytes long. - * - * Requires a preallocated environment from rd_kafka_snappy_init_env. - * The environment does not keep state over individual calls - * of this function, just preallocates the memory. - */ -int rd_kafka_snappy_compress(struct snappy_env *env, - const char *input, - size_t input_length, - char *compressed, size_t *compressed_length) -{ - struct source reader = { - .ptr = input, - .left = input_length - }; - struct sink writer = { - .dest = compressed, - }; - int err = sn_compress(env, &reader, &writer); - - /* Compute how many bytes were added */ - *compressed_length = (writer.dest - compressed); - return err; -} -EXPORT_SYMBOL(rd_kafka_snappy_compress); - -/** - * rd_kafka_snappy_uncompress - Uncompress a snappy compressed buffer - * @compressed: Input buffer with compressed data - * @n: length of compressed buffer - * @uncompressed: buffer for uncompressed data - * - * The uncompressed data buffer must be at least - * rd_kafka_snappy_uncompressed_length(compressed) bytes long. - * - * Return 0 on success, otherwise an negative error code. - */ -int rd_kafka_snappy_uncompress(const char *compressed, size_t n, char *uncompressed) -{ - struct source reader = { - .ptr = compressed, - .left = n - }; - struct writer output = { - .base = uncompressed, - .op = uncompressed - }; - return internal_uncompress(&reader, &output, 0xffffffff); -} -EXPORT_SYMBOL(rd_kafka_snappy_uncompress); -#endif - -static inline void clear_env(struct snappy_env *env) -{ - memset(env, 0, sizeof(*env)); -} - -#ifdef SG -/** - * rd_kafka_snappy_init_env_sg - Allocate snappy compression environment - * @env: Environment to preallocate - * @sg: Input environment ever does scather gather - * - * If false is passed to sg then multiple entries in an iovec - * are not legal. - * Returns 0 on success, otherwise negative errno. - * Must run in process context. - */ -int rd_kafka_snappy_init_env_sg(struct snappy_env *env, bool sg) -{ - if (rd_kafka_snappy_init_env(env) < 0) - goto error; - - if (sg) { - env->scratch = vmalloc(kblock_size); - if (!env->scratch) - goto error; - env->scratch_output = - vmalloc(rd_kafka_snappy_max_compressed_length(kblock_size)); - if (!env->scratch_output) - goto error; - } - return 0; -error: - rd_kafka_snappy_free_env(env); - return -ENOMEM; -} -EXPORT_SYMBOL(rd_kafka_snappy_init_env_sg); -#endif - -/** - * rd_kafka_snappy_init_env - Allocate snappy compression environment - * @env: Environment to preallocate - * - * Passing multiple entries in an iovec is not allowed - * on the environment allocated here. - * Returns 0 on success, otherwise negative errno. - * Must run in process context. - */ -int rd_kafka_snappy_init_env(struct snappy_env *env) -{ - clear_env(env); - env->hash_table = vmalloc(sizeof(u16) * kmax_hash_table_size); - if (!env->hash_table) - return -ENOMEM; - return 0; -} -EXPORT_SYMBOL(rd_kafka_snappy_init_env); - -/** - * rd_kafka_snappy_free_env - Free an snappy compression environment - * @env: Environment to free. - * - * Must run in process context. - */ -void rd_kafka_snappy_free_env(struct snappy_env *env) -{ - vfree(env->hash_table); -#ifdef SG - vfree(env->scratch); - vfree(env->scratch_output); -#endif - clear_env(env); -} -EXPORT_SYMBOL(rd_kafka_snappy_free_env); - -#ifdef __GNUC__ -#pragma GCC diagnostic pop /* -Wcast-align ignore */ -#endif |