Return-Path: X-Original-To: apmail-couchdb-commits-archive@www.apache.org Delivered-To: apmail-couchdb-commits-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id D345D10A34 for ; Thu, 13 Mar 2014 14:09:44 +0000 (UTC) Received: (qmail 37443 invoked by uid 500); 13 Mar 2014 14:09:43 -0000 Delivered-To: apmail-couchdb-commits-archive@couchdb.apache.org Received: (qmail 37256 invoked by uid 500); 13 Mar 2014 14:09:41 -0000 Mailing-List: contact commits-help@couchdb.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: dev@couchdb.apache.org Delivered-To: mailing list commits@couchdb.apache.org Received: (qmail 37229 invoked by uid 99); 13 Mar 2014 14:09:40 -0000 Received: from tyr.zones.apache.org (HELO tyr.zones.apache.org) (140.211.11.114) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 13 Mar 2014 14:09:40 +0000 Received: by tyr.zones.apache.org (Postfix, from userid 65534) id 3609A944213; Thu, 13 Mar 2014 14:09:40 +0000 (UTC) Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: dch@apache.org To: commits@couchdb.apache.org Date: Thu, 13 Mar 2014 14:09:41 -0000 Message-Id: In-Reply-To: References: X-Mailer: ASF-Git Admin Mailer Subject: [2/3] snappy: import 1.1.1 http://git-wip-us.apache.org/repos/asf/couchdb/blob/1eb889b2/src/snappy/c_src/snappy/snappy.cc ---------------------------------------------------------------------- diff --git a/src/snappy/c_src/snappy/snappy.cc b/src/snappy/c_src/snappy/snappy.cc new file mode 100644 index 0000000..a591aba --- /dev/null +++ b/src/snappy/c_src/snappy/snappy.cc @@ -0,0 +1,1021 @@ +// 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. + +#include "snappy.h" +#include "snappy-internal.h" +#include "snappy-sinksource.h" + +#include + +#include +#include +#include + + +namespace snappy { + +// 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 uint32 HashBytes(uint32 bytes, int shift) { + uint32 kMul = 0x1e35a7bd; + return (bytes * kMul) >> shift; +} +static inline uint32 Hash(const char* p, int shift) { + return HashBytes(UNALIGNED_LOAD32(p), shift); +} + +size_t MaxCompressedLength(size_t source_len) { + // 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: + return 32 + source_len + source_len/6; +} + +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 +}; + +// 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 IncrementalCopy(const char* src, char* op, int 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 +// and patterns marked as intervals: +// +// abxxxxxxxxxxxx +// [------] src +// [------] op +// +// a single eight-byte copy from to will repeat the pattern once, +// after which we can move two bytes without moving : +// +// 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. + +namespace { + +const int kMaxIncrementCopyOverflow = 10; + +} // namespace + +static inline void IncrementalCopyFastPath(const char* src, char* op, int len) { + while (op - src < 8) { + UNALIGNED_STORE64(op, UNALIGNED_LOAD64(src)); + len -= op - src; + op += op - src; + } + while (len > 0) { + UNALIGNED_STORE64(op, UNALIGNED_LOAD64(src)); + src += 8; + op += 8; + len -= 8; + } +} + +static inline char* EmitLiteral(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_STORE64(op, UNALIGNED_LOAD64(literal)); + UNALIGNED_STORE64(op + 8, UNALIGNED_LOAD64(literal + 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++; + } + assert(count >= 1); + assert(count <= 4); + *base = LITERAL | ((59+count) << 2); + } + memcpy(op, literal, len); + return op + len; +} + +static inline char* EmitCopyLessThan64(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; + assert(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); + LittleEndian::Store16(op, offset); + op += 2; + } + return op; +} + +static inline char* EmitCopy(char* op, int offset, int len) { + // Emit 64 byte copies but make sure to keep at least four bytes reserved + while (len >= 68) { + op = EmitCopyLessThan64(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 = EmitCopyLessThan64(op, offset, 60); + len -= 60; + } + + // Emit remainder + op = EmitCopyLessThan64(op, offset, len); + return op; +} + + +bool GetUncompressedLength(const char* start, size_t n, size_t* result) { + uint32 v = 0; + const char* limit = start + n; + if (Varint::Parse32WithLimit(start, limit, &v) != NULL) { + *result = v; + return true; + } else { + return false; + } +} + +namespace internal { +uint16* WorkingMemory::GetHashTable(size_t input_size, int* table_size) { + // 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. + assert(kMaxHashTableSize >= 256); + int htsize = 256; + while (htsize < kMaxHashTableSize && htsize < input_size) { + htsize <<= 1; + } + CHECK_EQ(0, htsize & (htsize - 1)) << ": must be power of two"; + CHECK_LE(htsize, kMaxHashTableSize) << ": hash table too large"; + + uint16* table; + if (htsize <= ARRAYSIZE(small_table_)) { + table = small_table_; + } else { + if (large_table_ == NULL) { + large_table_ = new uint16[kMaxHashTableSize]; + } + table = large_table_; + } + + *table_size = htsize; + memset(table, 0, htsize * sizeof(*table)); + return table; +} +} // end namespace internal + +// For 0 <= offset <= 4, GetUint32AtOffset(UNALIGNED_LOAD64(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 uint32. +static inline uint32 GetUint32AtOffset(uint64 v, int offset) { + DCHECK(0 <= offset && offset <= 4) << offset; + return v >> (LittleEndian::IsLittleEndian() ? 8 * offset : 32 - 8 * offset); +} + +// 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". +namespace internal { +char* CompressFragment(const char* const input, + const size_t input_size, + char* op, + uint16* table, + const int table_size) { + // "ip" is the input pointer, and "op" is the output pointer. + const char* ip = input; + CHECK_LE(input_size, kBlockSize); + CHECK_EQ(table_size & (table_size - 1), 0) << ": table must be power of two"; + const int shift = 32 - Bits::Log2Floor(table_size); + DCHECK_EQ(kuint32max >> shift, table_size - 1); + const char* ip_end = input + input_size; + const char* base_ip = 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 int kInputMarginBytes = 15; + if (PREDICT_TRUE(input_size >= kInputMarginBytes)) { + const char* ip_limit = input + input_size - kInputMarginBytes; + + for (uint32 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 compressible 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. + uint32 skip = 32; + + const char* next_ip = ip; + const char* candidate; + do { + ip = next_ip; + uint32 hash = next_hash; + DCHECK_EQ(hash, Hash(ip, shift)); + uint32 bytes_between_hash_lookups = skip++ >> 5; + next_ip = ip + bytes_between_hash_lookups; + if (PREDICT_FALSE(next_ip > ip_limit)) { + goto emit_remainder; + } + next_hash = Hash(next_ip, shift); + candidate = base_ip + table[hash]; + DCHECK_GE(candidate, base_ip); + DCHECK_LT(candidate, ip); + + table[hash] = ip - base_ip; + } while (PREDICT_TRUE(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 = EmitLiteral(op, next_emit, 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. + uint64 input_bytes = 0; + uint32 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 + FindMatchLength(candidate + 4, ip + 4, ip_end); + ip += matched; + int offset = base - candidate; + DCHECK_EQ(0, memcmp(base, candidate, matched)); + op = EmitCopy(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 (PREDICT_FALSE(ip >= ip_limit)) { + goto emit_remainder; + } + input_bytes = UNALIGNED_LOAD64(insert_tail); + uint32 prev_hash = HashBytes(GetUint32AtOffset(input_bytes, 0), shift); + table[prev_hash] = ip - base_ip - 1; + uint32 cur_hash = HashBytes(GetUint32AtOffset(input_bytes, 1), shift); + candidate = base_ip + table[cur_hash]; + candidate_bytes = UNALIGNED_LOAD32(candidate); + table[cur_hash] = ip - base_ip; + } while (GetUint32AtOffset(input_bytes, 1) == candidate_bytes); + + next_hash = HashBytes(GetUint32AtOffset(input_bytes, 2), shift); + ++ip; + } + } + + emit_remainder: + // Emit the remaining bytes as a literal + if (next_emit < ip_end) { + op = EmitLiteral(op, next_emit, ip_end - next_emit, false); + } + + return op; +} +} // end namespace internal + +// Signature of output types needed by decompression code. +// The decompression code is templatized on a type that obeys this +// signature so that we do not pay virtual function call overhead in +// the middle of a tight decompression loop. +// +// class DecompressionWriter { +// public: +// // Called before decompression +// void SetExpectedLength(size_t length); +// +// // Called after decompression +// bool CheckLength() const; +// +// // Called repeatedly during decompression +// bool Append(const char* ip, uint32 length, bool allow_fast_path); +// bool AppendFromSelf(uint32 offset, uint32 length); +// }; +// +// "allow_fast_path" is a parameter that says if there is at least 16 +// readable bytes in "ip". It is currently only used by SnappyArrayWriter. + +// ----------------------------------------------------------------------- +// 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 uint32 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 uint16 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 +}; + +// In debug mode, allow optional computation of the table at startup. +// Also, check that the decompression table is correct. +#ifndef NDEBUG +DEFINE_bool(snappy_dump_decompression_table, false, + "If true, we print the decompression table at startup."); + +static uint16 MakeEntry(unsigned int extra, + unsigned int len, + unsigned int copy_offset) { + // Check that all of the fields fit within the allocated space + DCHECK_EQ(extra, extra & 0x7); // At most 3 bits + DCHECK_EQ(copy_offset, copy_offset & 0x7); // At most 3 bits + DCHECK_EQ(len, len & 0x7f); // At most 7 bits + return len | (copy_offset << 8) | (extra << 11); +} + +static void ComputeTable() { + uint16 dst[256]; + + // Place invalid entries in all places to detect missing initialization + int assigned = 0; + for (int i = 0; i < 256; i++) { + dst[i] = 0xffff; + } + + // Small LITERAL entries. We store (len-1) in the top 6 bits. + for (unsigned int len = 1; len <= 60; len++) { + dst[LITERAL | ((len-1) << 2)] = MakeEntry(0, len, 0); + assigned++; + } + + // Large LITERAL entries. We use 60..63 in the high 6 bits to + // encode the number of bytes of length info that follow the opcode. + for (unsigned int extra_bytes = 1; extra_bytes <= 4; extra_bytes++) { + // We set the length field in the lookup table to 1 because extra + // bytes encode len-1. + dst[LITERAL | ((extra_bytes+59) << 2)] = MakeEntry(extra_bytes, 1, 0); + assigned++; + } + + // COPY_1_BYTE_OFFSET. + // + // The tag byte in the compressed data stores len-4 in 3 bits, and + // offset/256 in 5 bits. offset%256 is stored in the next byte. + // + // This format is used for length in range [4..11] and offset in + // range [0..2047] + for (unsigned int len = 4; len < 12; len++) { + for (unsigned int offset = 0; offset < 2048; offset += 256) { + dst[COPY_1_BYTE_OFFSET | ((len-4)<<2) | ((offset>>8)<<5)] = + MakeEntry(1, len, offset>>8); + assigned++; + } + } + + // COPY_2_BYTE_OFFSET. + // Tag contains len-1 in top 6 bits, and offset in next two bytes. + for (unsigned int len = 1; len <= 64; len++) { + dst[COPY_2_BYTE_OFFSET | ((len-1)<<2)] = MakeEntry(2, len, 0); + assigned++; + } + + // COPY_4_BYTE_OFFSET. + // Tag contents len-1 in top 6 bits, and offset in next four bytes. + for (unsigned int len = 1; len <= 64; len++) { + dst[COPY_4_BYTE_OFFSET | ((len-1)<<2)] = MakeEntry(4, len, 0); + assigned++; + } + + // Check that each entry was initialized exactly once. + CHECK_EQ(assigned, 256); + for (int i = 0; i < 256; i++) { + CHECK_NE(dst[i], 0xffff); + } + + if (FLAGS_snappy_dump_decompression_table) { + printf("static const uint16 char_table[256] = {\n "); + for (int i = 0; i < 256; i++) { + printf("0x%04x%s", + dst[i], + ((i == 255) ? "\n" : (((i%8) == 7) ? ",\n " : ", "))); + } + printf("};\n"); + } + + // Check that computed table matched recorded table + for (int i = 0; i < 256; i++) { + CHECK_EQ(dst[i], char_table[i]); + } +} +REGISTER_MODULE_INITIALIZER(snappy, ComputeTable()); +#endif /* !NDEBUG */ + +// Helper class for decompression +class SnappyDecompressor { + private: + 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 + uint32 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 + + // Ensure that all of the tag metadata for the next tag is available + // in [ip_..ip_limit_-1]. Also ensures that [ip,ip+4] is readable even + // if (ip_limit_ - ip_ < 5). + // + // Returns true on success, false on error or end of input. + bool RefillTag(); + + public: + explicit SnappyDecompressor(Source* reader) + : reader_(reader), + ip_(NULL), + ip_limit_(NULL), + peeked_(0), + eof_(false) { + } + + ~SnappyDecompressor() { + // Advance past any bytes we peeked at from the reader + reader_->Skip(peeked_); + } + + // Returns true iff we have hit the end of the input without an error. + bool eof() const { + return eof_; + } + + // 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. + bool ReadUncompressedLength(uint32* result) { + DCHECK(ip_ == NULL); // Must not have read anything yet + // Length is encoded in 1..5 bytes + *result = 0; + uint32 shift = 0; + while (true) { + if (shift >= 32) return false; + size_t n; + const char* ip = reader_->Peek(&n); + if (n == 0) return false; + const unsigned char c = *(reinterpret_cast(ip)); + reader_->Skip(1); + *result |= static_cast(c & 0x7f) << shift; + if (c < 128) { + break; + } + shift += 7; + } + return true; + } + + // Process the next item found in the input. + // Returns true if successful, false on error or end of input. + template + void DecompressAllTags(Writer* writer) { + const char* ip = ip_; + for ( ;; ) { + if (ip_limit_ - ip < 5) { + ip_ = ip; + if (!RefillTag()) return; + ip = ip_; + } + + const unsigned char c = *(reinterpret_cast(ip++)); + const uint32 entry = char_table[c]; + const uint32 trailer = LittleEndian::Load32(ip) & wordmask[entry >> 11]; + ip += entry >> 11; + const uint32 length = entry & 0xff; + + if ((c & 0x3) == LITERAL) { + uint32 literal_length = length + trailer; + uint32 avail = ip_limit_ - ip; + while (avail < literal_length) { + bool allow_fast_path = (avail >= 16); + if (!writer->Append(ip, avail, allow_fast_path)) return; + literal_length -= avail; + reader_->Skip(peeked_); + size_t n; + ip = reader_->Peek(&n); + avail = n; + peeked_ = avail; + if (avail == 0) return; // Premature end of input + ip_limit_ = ip + avail; + } + bool allow_fast_path = (avail >= 16); + if (!writer->Append(ip, literal_length, allow_fast_path)) { + return; + } + ip += literal_length; + } else { + // 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 uint32 copy_offset = entry & 0x700; + if (!writer->AppendFromSelf(copy_offset + trailer, length)) { + return; + } + } + } + } +}; + +bool SnappyDecompressor::RefillTag() { + const char* ip = ip_; + if (ip == ip_limit_) { + // Fetch a new fragment from the reader + reader_->Skip(peeked_); // All peeked bytes are used up + size_t n; + ip = reader_->Peek(&n); + peeked_ = n; + if (n == 0) { + eof_ = true; + return false; + } + ip_limit_ = ip + n; + } + + // Read the tag character + DCHECK_LT(ip, ip_limit_); + const unsigned char c = *(reinterpret_cast(ip)); + const uint32 entry = char_table[c]; + const uint32 needed = (entry >> 11) + 1; // +1 byte for 'c' + DCHECK_LE(needed, sizeof(scratch_)); + + // Read more bytes from reader if needed + uint32 nbuf = 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(scratch_, ip, nbuf); + reader_->Skip(peeked_); // All peeked bytes are used up + peeked_ = 0; + while (nbuf < needed) { + size_t length; + const char* src = reader_->Peek(&length); + if (length == 0) return false; + uint32 to_add = min(needed - nbuf, length); + memcpy(scratch_ + nbuf, src, to_add); + nbuf += to_add; + reader_->Skip(to_add); + } + DCHECK_EQ(nbuf, needed); + ip_ = scratch_; + ip_limit_ = scratch_ + needed; + } else if (nbuf < 5) { + // Have enough bytes, but move into scratch_ so that we do not + // read past end of input + memmove(scratch_, ip, nbuf); + reader_->Skip(peeked_); // All peeked bytes are used up + peeked_ = 0; + ip_ = scratch_; + ip_limit_ = scratch_ + nbuf; + } else { + // Pass pointer to buffer returned by reader_. + ip_ = ip; + } + return true; +} + +template +static bool InternalUncompress(Source* r, + Writer* writer, + uint32 max_len) { + // Read the uncompressed length from the front of the compressed input + SnappyDecompressor decompressor(r); + uint32 uncompressed_len = 0; + if (!decompressor.ReadUncompressedLength(&uncompressed_len)) return false; + // Protect against possible DoS attack + if (static_cast(uncompressed_len) > max_len) { + return false; + } + + writer->SetExpectedLength(uncompressed_len); + + // Process the entire input + decompressor.DecompressAllTags(writer); + return (decompressor.eof() && writer->CheckLength()); +} + +bool GetUncompressedLength(Source* source, uint32* result) { + SnappyDecompressor decompressor(source); + return decompressor.ReadUncompressedLength(result); +} + +size_t Compress(Source* reader, Sink* writer) { + size_t written = 0; + int N = reader->Available(); + char ulength[Varint::kMax32]; + char* p = Varint::Encode32(ulength, N); + writer->Append(ulength, p-ulength); + written += (p - ulength); + + internal::WorkingMemory wmem; + char* scratch = NULL; + char* scratch_output = NULL; + + while (N > 0) { + // Get next block to compress (without copying if possible) + size_t fragment_size; + const char* fragment = reader->Peek(&fragment_size); + DCHECK_NE(fragment_size, 0) << ": premature end of input"; + const int num_to_read = min(N, kBlockSize); + 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 { + // Read into scratch buffer + if (scratch == NULL) { + // If this is the last iteration, we want to allocate N bytes + // of space, otherwise the max possible kBlockSize space. + // num_to_read contains exactly the correct value + scratch = new char[num_to_read]; + } + memcpy(scratch, fragment, bytes_read); + reader->Skip(bytes_read); + + while (bytes_read < num_to_read) { + fragment = reader->Peek(&fragment_size); + size_t n = min(fragment_size, num_to_read - bytes_read); + memcpy(scratch + bytes_read, fragment, n); + bytes_read += n; + reader->Skip(n); + } + DCHECK_EQ(bytes_read, num_to_read); + fragment = scratch; + fragment_size = num_to_read; + } + DCHECK_EQ(fragment_size, num_to_read); + + // Get encoding table for compression + int table_size; + uint16* table = wmem.GetHashTable(num_to_read, &table_size); + + // Compress input_fragment and append to dest + const int max_output = MaxCompressedLength(num_to_read); + + // Need a scratch buffer for the output, in case the byte sink doesn't + // have room for us directly. + if (scratch_output == NULL) { + scratch_output = new char[max_output]; + } else { + // Since we encode kBlockSize regions followed by a region + // which is <= kBlockSize in length, a previously allocated + // scratch_output[] region is big enough for this iteration. + } + char* dest = writer->GetAppendBuffer(max_output, scratch_output); + char* end = internal::CompressFragment(fragment, fragment_size, + dest, table, table_size); + writer->Append(dest, end - dest); + written += (end - dest); + + N -= num_to_read; + reader->Skip(pending_advance); + } + + delete[] scratch; + delete[] scratch_output; + + return written; +} + +// ----------------------------------------------------------------------- +// Flat array interfaces +// ----------------------------------------------------------------------- + +// A type that writes to a flat array. +// Note that this is not a "ByteSink", but a type that matches the +// Writer template argument to SnappyDecompressor::DecompressAllTags(). +class SnappyArrayWriter { + private: + char* base_; + char* op_; + char* op_limit_; + + public: + inline explicit SnappyArrayWriter(char* dst) + : base_(dst), + op_(dst) { + } + + inline void SetExpectedLength(size_t len) { + op_limit_ = op_ + len; + } + + inline bool CheckLength() const { + return op_ == op_limit_; + } + + inline bool Append(const char* ip, uint32 len, bool allow_fast_path) { + char* op = op_; + const int space_left = op_limit_ - op; + if (allow_fast_path && len <= 16 && space_left >= 16) { + // Fast path, used for the majority (about 90%) of dynamic invocations. + UNALIGNED_STORE64(op, UNALIGNED_LOAD64(ip)); + UNALIGNED_STORE64(op + 8, UNALIGNED_LOAD64(ip + 8)); + } else { + if (space_left < len) { + return false; + } + memcpy(op, ip, len); + } + op_ = op + len; + return true; + } + + inline bool AppendFromSelf(uint32 offset, uint32 len) { + char* op = op_; + const int space_left = op_limit_ - op; + + if (op - 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_STORE64(op, UNALIGNED_LOAD64(op - offset)); + UNALIGNED_STORE64(op + 8, UNALIGNED_LOAD64(op - offset + 8)); + } else { + if (space_left >= len + kMaxIncrementCopyOverflow) { + IncrementalCopyFastPath(op - offset, op, len); + } else { + if (space_left < len) { + return false; + } + IncrementalCopy(op - offset, op, len); + } + } + + op_ = op + len; + return true; + } +}; + +bool RawUncompress(const char* compressed, size_t n, char* uncompressed) { + ByteArraySource reader(compressed, n); + return RawUncompress(&reader, uncompressed); +} + +bool RawUncompress(Source* compressed, char* uncompressed) { + SnappyArrayWriter output(uncompressed); + return InternalUncompress(compressed, &output, kuint32max); +} + +bool Uncompress(const char* compressed, size_t n, string* uncompressed) { + size_t ulength; + if (!GetUncompressedLength(compressed, n, &ulength)) { + return false; + } + // Protect against possible DoS attack + if ((static_cast(ulength) + uncompressed->size()) > + uncompressed->max_size()) { + return false; + } + STLStringResizeUninitialized(uncompressed, ulength); + return RawUncompress(compressed, n, string_as_array(uncompressed)); +} + + +// A Writer that drops everything on the floor and just does validation +class SnappyDecompressionValidator { + private: + size_t expected_; + size_t produced_; + + public: + inline SnappyDecompressionValidator() : produced_(0) { } + inline void SetExpectedLength(size_t len) { + expected_ = len; + } + inline bool CheckLength() const { + return expected_ == produced_; + } + inline bool Append(const char* ip, uint32 len, bool allow_fast_path) { + produced_ += len; + return produced_ <= expected_; + } + inline bool AppendFromSelf(uint32 offset, uint32 len) { + if (produced_ <= offset - 1u) return false; // -1u catches offset==0 + produced_ += len; + return produced_ <= expected_; + } +}; + +bool IsValidCompressedBuffer(const char* compressed, size_t n) { + ByteArraySource reader(compressed, n); + SnappyDecompressionValidator writer; + return InternalUncompress(&reader, &writer, kuint32max); +} + +void RawCompress(const char* input, + size_t input_length, + char* compressed, + size_t* compressed_length) { + ByteArraySource reader(input, input_length); + UncheckedByteArraySink writer(compressed); + Compress(&reader, &writer); + + // Compute how many bytes were added + *compressed_length = (writer.CurrentDestination() - compressed); +} + +size_t Compress(const char* input, size_t input_length, string* compressed) { + // Pre-grow the buffer to the max length of the compressed output + compressed->resize(MaxCompressedLength(input_length)); + + size_t compressed_length; + RawCompress(input, input_length, string_as_array(compressed), + &compressed_length); + compressed->resize(compressed_length); + return compressed_length; +} + + +} // end namespace snappy + http://git-wip-us.apache.org/repos/asf/couchdb/blob/1eb889b2/src/snappy/c_src/snappy/snappy.h ---------------------------------------------------------------------- diff --git a/src/snappy/c_src/snappy/snappy.h b/src/snappy/c_src/snappy/snappy.h new file mode 100644 index 0000000..8d6ef22 --- /dev/null +++ b/src/snappy/c_src/snappy/snappy.h @@ -0,0 +1,155 @@ +// Copyright 2005 and onwards Google Inc. +// +// 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. +// +// A light-weight compression algorithm. It is designed for speed of +// compression and decompression, rather than for the utmost in space +// savings. +// +// For getting better compression ratios when you are compressing data +// with long repeated sequences or compressing data that is similar to +// other data, while still compressing fast, you might look at first +// using BMDiff and then compressing the output of BMDiff with +// Snappy. + +#ifndef UTIL_SNAPPY_SNAPPY_H__ +#define UTIL_SNAPPY_SNAPPY_H__ + +#include +#include + +#include "snappy-stubs-public.h" + +namespace snappy { + class Source; + class Sink; + + // ------------------------------------------------------------------------ + // Generic compression/decompression routines. + // ------------------------------------------------------------------------ + + // Compress the bytes read from "*source" and append to "*sink". Return the + // number of bytes written. + size_t Compress(Source* source, Sink* sink); + + bool GetUncompressedLength(Source* source, uint32* result); + + // ------------------------------------------------------------------------ + // Higher-level string based routines (should be sufficient for most users) + // ------------------------------------------------------------------------ + + // Sets "*output" to the compressed version of "input[0,input_length-1]". + // Original contents of *output are lost. + // + // REQUIRES: "input[]" is not an alias of "*output". + size_t Compress(const char* input, size_t input_length, string* output); + + // Decompresses "compressed[0,compressed_length-1]" to "*uncompressed". + // Original contents of "*uncompressed" are lost. + // + // REQUIRES: "compressed[]" is not an alias of "*uncompressed". + // + // returns false if the message is corrupted and could not be decompressed + bool Uncompress(const char* compressed, size_t compressed_length, + string* uncompressed); + + + // ------------------------------------------------------------------------ + // Lower-level character array based routines. May be useful for + // efficiency reasons in certain circumstances. + // ------------------------------------------------------------------------ + + // REQUIRES: "compressed" must point to an area of memory that is at + // least "MaxCompressedLength(input_length)" bytes in length. + // + // Takes the data stored in "input[0..input_length]" and stores + // it in the array pointed to by "compressed". + // + // "*compressed_length" is set to the length of the compressed output. + // + // Example: + // char* output = new char[snappy::MaxCompressedLength(input_length)]; + // size_t output_length; + // RawCompress(input, input_length, output, &output_length); + // ... Process(output, output_length) ... + // delete [] output; + void RawCompress(const char* input, + size_t input_length, + char* compressed, + size_t* compressed_length); + + // Given data in "compressed[0..compressed_length-1]" generated by + // calling the Snappy::Compress routine, this routine + // stores the uncompressed data to + // uncompressed[0..GetUncompressedLength(compressed)-1] + // returns false if the message is corrupted and could not be decrypted + bool RawUncompress(const char* compressed, size_t compressed_length, + char* uncompressed); + + // Given data from the byte source 'compressed' generated by calling + // the Snappy::Compress routine, this routine stores the uncompressed + // data to + // uncompressed[0..GetUncompressedLength(compressed,compressed_length)-1] + // returns false if the message is corrupted and could not be decrypted + bool RawUncompress(Source* compressed, char* uncompressed); + + // Returns the maximal size of the compressed representation of + // input data that is "source_bytes" bytes in length; + size_t MaxCompressedLength(size_t source_bytes); + + // REQUIRES: "compressed[]" was produced by RawCompress() or Compress() + // Returns true and stores the length of the uncompressed data in + // *result normally. Returns false on parsing error. + // This operation takes O(1) time. + bool GetUncompressedLength(const char* compressed, size_t compressed_length, + size_t* result); + + // Returns true iff the contents of "compressed[]" can be uncompressed + // successfully. Does not return the uncompressed data. Takes + // time proportional to compressed_length, but is usually at least + // a factor of four faster than actual decompression. + bool IsValidCompressedBuffer(const char* compressed, + size_t compressed_length); + + // *** DO NOT CHANGE THE VALUE OF kBlockSize *** + // + // New Compression code chops up the input into blocks of at most + // the following size. This ensures that back-references in the + // output never cross kBlockSize block boundaries. This can be + // helpful in implementing blocked decompression. However the + // decompression code should not rely on this guarantee since older + // compression code may not obey it. + static const int kBlockLog = 15; + static const int kBlockSize = 1 << kBlockLog; + + static const int kMaxHashTableBits = 14; + static const int kMaxHashTableSize = 1 << kMaxHashTableBits; + +} // end namespace snappy + + +#endif // UTIL_SNAPPY_SNAPPY_H__ http://git-wip-us.apache.org/repos/asf/couchdb/blob/1eb889b2/src/snappy/c_src/snappy_nif.cc ---------------------------------------------------------------------- diff --git a/src/snappy/c_src/snappy_nif.cc b/src/snappy/c_src/snappy_nif.cc new file mode 100644 index 0000000..93c1859 --- /dev/null +++ b/src/snappy/c_src/snappy_nif.cc @@ -0,0 +1,265 @@ +/** + * Copyright 2011, Filipe David Manana + * Web: http://github.com/fdmanana/snappy-erlang-nif + * + * Licensed under the Apache License, Version 2.0 (the "License"); you may not + * use this file except in compliance with the License. You may obtain a copy of + * the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the + * License for the specific language governing permissions and limitations under + * the License. + **/ + +#include +#include + +#include "erl_nif_compat.h" +#include "snappy/snappy.h" +#include "snappy/snappy-sinksource.h" + +#ifdef OTP_R13B03 +#error OTP R13B03 not supported. Upgrade to R13B04 or later. +#endif + +#ifdef __cplusplus +#define BEGIN_C extern "C" { +#define END_C } +#else +#define BEGIN_C +#define END_C +#endif + +#define SC_PTR(c) reinterpret_cast(c) + +class SnappyNifSink : public snappy::Sink +{ + public: + SnappyNifSink(ErlNifEnv* e); + ~SnappyNifSink(); + + void Append(const char* data, size_t n); + char* GetAppendBuffer(size_t len, char* scratch); + ErlNifBinary& getBin(); + + private: + ErlNifEnv* env; + ErlNifBinary bin; + size_t length; +}; + +SnappyNifSink::SnappyNifSink(ErlNifEnv* e) : env(e), length(0) +{ + if(!enif_alloc_binary_compat(env, 0, &bin)) { + env = NULL; + throw std::bad_alloc(); + } +} + +SnappyNifSink::~SnappyNifSink() +{ + if(env != NULL) { + enif_release_binary_compat(env, &bin); + } +} + +void +SnappyNifSink::Append(const char *data, size_t n) +{ + if(data != (SC_PTR(bin.data) + length)) { + memcpy(bin.data + length, data, n); + } + length += n; +} + +char* +SnappyNifSink::GetAppendBuffer(size_t len, char* scratch) +{ + size_t sz; + + if((length + len) > bin.size) { + sz = (len * 4) < 8192 ? 8192 : (len * 4); + + if(!enif_realloc_binary_compat(env, &bin, bin.size + sz)) { + throw std::bad_alloc(); + } + } + + return SC_PTR(bin.data) + length; +} + +ErlNifBinary& +SnappyNifSink::getBin() +{ + if(bin.size > length) { + if(!enif_realloc_binary_compat(env, &bin, length)) { + throw std::bad_alloc(); + } + } + return bin; +} + + +static inline ERL_NIF_TERM +make_atom(ErlNifEnv* env, const char* name) +{ + ERL_NIF_TERM ret; + if(enif_make_existing_atom_compat(env, name, &ret, ERL_NIF_LATIN1)) { + return ret; + } + return enif_make_atom(env, name); +} + + +static inline ERL_NIF_TERM +make_ok(ErlNifEnv* env, ERL_NIF_TERM mesg) +{ + ERL_NIF_TERM ok = make_atom(env, "ok"); + return enif_make_tuple2(env, ok, mesg); +} + + +static inline ERL_NIF_TERM +make_error(ErlNifEnv* env, const char* mesg) +{ + ERL_NIF_TERM error = make_atom(env, "error"); + return enif_make_tuple2(env, error, make_atom(env, mesg)); +} + + +BEGIN_C + + +ERL_NIF_TERM +snappy_compress(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) +{ + ErlNifBinary input; + + if(!enif_inspect_iolist_as_binary(env, argv[0], &input)) { + return enif_make_badarg(env); + } + + try { + snappy::ByteArraySource source(SC_PTR(input.data), input.size); + SnappyNifSink sink(env); + snappy::Compress(&source, &sink); + return make_ok(env, enif_make_binary(env, &sink.getBin())); + } catch(std::bad_alloc e) { + return make_error(env, "insufficient_memory"); + } catch(...) { + return make_error(env, "unknown"); + } +} + + +ERL_NIF_TERM +snappy_decompress(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) +{ + ErlNifBinary bin; + ErlNifBinary ret; + size_t len; + + if(!enif_inspect_iolist_as_binary(env, argv[0], &bin)) { + return enif_make_badarg(env); + } + + try { + if(!snappy::GetUncompressedLength(SC_PTR(bin.data), bin.size, &len)) { + return make_error(env, "data_not_compressed"); + } + + if(!enif_alloc_binary_compat(env, len, &ret)) { + return make_error(env, "insufficient_memory"); + } + + if(!snappy::RawUncompress(SC_PTR(bin.data), bin.size, + SC_PTR(ret.data))) { + return make_error(env, "corrupted_data"); + } + + return make_ok(env, enif_make_binary(env, &ret)); + } catch(...) { + return make_error(env, "unknown"); + } +} + + +ERL_NIF_TERM +snappy_uncompressed_length(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) +{ + ErlNifBinary bin; + size_t len; + + if(!enif_inspect_iolist_as_binary(env, argv[0], &bin)) { + return enif_make_badarg(env); + } + + try { + if(!snappy::GetUncompressedLength(SC_PTR(bin.data), bin.size, &len)) { + return make_error(env, "data_not_compressed"); + } + return make_ok(env, enif_make_ulong(env, len)); + } catch(...) { + return make_error(env, "unknown"); + } +} + + +ERL_NIF_TERM +snappy_is_valid(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) +{ + ErlNifBinary bin; + + if (!enif_inspect_iolist_as_binary(env, argv[0], &bin)) { + return enif_make_badarg(env); + } + + try { + if(snappy::IsValidCompressedBuffer(SC_PTR(bin.data), bin.size)) { + return make_atom(env, "true"); + } else { + return make_atom(env, "false"); + } + } catch(...) { + return make_error(env, "unknown"); + } +} + + +int +on_load(ErlNifEnv* env, void** priv, ERL_NIF_TERM info) +{ + return 0; +} + + +int +on_reload(ErlNifEnv* env, void** priv, ERL_NIF_TERM info) +{ + return 0; +} + + +int +on_upgrade(ErlNifEnv* env, void** priv, void** old_priv, ERL_NIF_TERM info) +{ + return 0; +} + + +static ErlNifFunc nif_functions[] = { + {"compress", 1, snappy_compress}, + {"decompress", 1, snappy_decompress}, + {"uncompressed_length", 1, snappy_uncompressed_length}, + {"is_valid", 1, snappy_is_valid} +}; + + +ERL_NIF_INIT(snappy, nif_functions, &on_load, &on_reload, &on_upgrade, NULL); + + +END_C http://git-wip-us.apache.org/repos/asf/couchdb/blob/1eb889b2/src/snappy/erl_nif_compat.h ---------------------------------------------------------------------- diff --git a/src/snappy/erl_nif_compat.h b/src/snappy/erl_nif_compat.h deleted file mode 100644 index b8eb9b0..0000000 --- a/src/snappy/erl_nif_compat.h +++ /dev/null @@ -1,129 +0,0 @@ -/* Copyright (c) 2010-2011 Basho Technologies, Inc. - * With some minor modifications by Filipe David Manana - * - * - * This file is provided to you under the Apache License, - * Version 2.0 (the "License"); you may not use this file - * except in compliance with the License. You may obtain - * a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, - * software distributed under the License is distributed on an - * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY - * KIND, either express or implied. See the License for the - * specific language governing permissions and limitations - * under the License. -*/ - -#ifndef ERL_NIF_COMPAT_H_ -#define ERL_NIF_COMPAT_H_ - -#ifdef __cplusplus -extern "C" { -#endif /* __cplusplus */ - -#include "erl_nif.h" - - -#if ERL_NIF_MAJOR_VERSION == 0 && ERL_NIF_MINOR_VERSION == 1 -#define OTP_R13B03 -#elif ERL_NIF_MAJOR_VERSION == 1 && ERL_NIF_MINOR_VERSION == 0 -#define OTP_R13B04 -#elif ERL_NIF_MAJOR_VERSION == 2 && ERL_NIF_MINOR_VERSION == 0 -#define OTP_R14A -#define OTP_R14B -#define OTP_R14B01 -#elif ERL_NIF_MAJOR_VERSION == 2 && ERL_NIF_MINOR_VERSION == 1 -#define OTP_R14B02 -#endif - - -#ifdef OTP_R13B03 - -#define enif_open_resource_type_compat enif_open_resource_type -#define enif_alloc_resource_compat enif_alloc_resource -#define enif_release_resource_compat enif_release_resource -#define enif_alloc_binary_compat enif_alloc_binary -#define enif_alloc_compat enif_alloc -#define enif_release_binary_compat enif_release_binary -#define enif_free_compat enif_free -#define enif_get_atom_compat enif_get_atom -#define enif_priv_data_compat enif_get_data -#define enif_make_uint_compat enif_make_ulong - -#define enif_make_existing_atom_compat(E, N, R, Enc) \ - enif_make_existing_atom(E, N, R) - -#define enif_make_string_compat(E, B, Enc) \ - enif_make_string(E, B) - -#endif /* R13B03 */ - - -#ifdef OTP_R13B04 - -#define enif_open_resource_type_compat enif_open_resource_type -#define enif_alloc_resource_compat enif_alloc_resource -#define enif_release_resource_compat enif_release_resource -#define enif_alloc_binary_compat enif_alloc_binary -#define enif_realloc_binary_compat enif_realloc_binary -#define enif_release_binary_compat enif_release_binary -#define enif_alloc_compat enif_alloc -#define enif_free_compat enif_free -#define enif_get_atom_compat enif_get_atom -#define enif_priv_data_compat enif_priv_data -#define enif_make_string_compat enif_make_string -#define enif_make_uint_compat enif_make_uint - -#define enif_make_existing_atom_compat(E, N, R, Enc) \ - enif_make_existing_atom(E, N, R) - - -#endif /* R13B04 */ - - -/* OTP R14A and future releases */ -#if !defined(OTP_R13B03) && !defined(OTP_R13B04) - -#define enif_open_resource_type_compat(E, N, D, F, T) \ - enif_open_resource_type(E, NULL, N, D, F, T) - -#define enif_alloc_resource_compat(E, T, S) \ - enif_alloc_resource(T, S) - -#define enif_release_resource_compat(E, H) \ - enif_release_resource(H) - -#define enif_alloc_binary_compat(E, S, B) \ - enif_alloc_binary(S, B) - -#define enif_realloc_binary_compat(E, S, B) \ - enif_realloc_binary(S, B) - -#define enif_release_binary_compat(E, B) \ - enif_release_binary(B) - -#define enif_alloc_compat(E, S) \ - enif_alloc(S) - -#define enif_free_compat(E, P) \ - enif_free(P) - -#define enif_get_atom_compat(E, T, B, S) \ - enif_get_atom(E, T, B, S, ERL_NIF_LATIN1) - -#define enif_priv_data_compat enif_priv_data -#define enif_make_string_compat enif_make_string -#define enif_make_existing_atom_compat enif_make_existing_atom -#define enif_make_uint_compat enif_make_uint - -#endif /* R14 and future releases */ - - -#ifdef __cplusplus -} -#endif /* __cplusplus */ - -#endif /* ERL_NIF_COMPAT_H_ */ http://git-wip-us.apache.org/repos/asf/couchdb/blob/1eb889b2/src/snappy/google-snappy/AUTHORS ---------------------------------------------------------------------- diff --git a/src/snappy/google-snappy/AUTHORS b/src/snappy/google-snappy/AUTHORS deleted file mode 100644 index 4858b37..0000000 --- a/src/snappy/google-snappy/AUTHORS +++ /dev/null @@ -1 +0,0 @@ -opensource@google.com http://git-wip-us.apache.org/repos/asf/couchdb/blob/1eb889b2/src/snappy/google-snappy/COPYING ---------------------------------------------------------------------- diff --git a/src/snappy/google-snappy/COPYING b/src/snappy/google-snappy/COPYING deleted file mode 100644 index 8d6bd9f..0000000 --- a/src/snappy/google-snappy/COPYING +++ /dev/null @@ -1,28 +0,0 @@ -Copyright 2011, 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. http://git-wip-us.apache.org/repos/asf/couchdb/blob/1eb889b2/src/snappy/google-snappy/config.h.in ---------------------------------------------------------------------- diff --git a/src/snappy/google-snappy/config.h.in b/src/snappy/google-snappy/config.h.in deleted file mode 100644 index 8f912f6..0000000 --- a/src/snappy/google-snappy/config.h.in +++ /dev/null @@ -1,128 +0,0 @@ -/* config.h.in. Generated from configure.ac by autoheader. */ - -/* Define if building universal (internal helper macro) */ -#undef AC_APPLE_UNIVERSAL_BUILD - -/* Define to 1 if the compiler supports __builtin_ctz and friends. */ -#undef HAVE_BUILTIN_CTZ - -/* Define to 1 if the compiler supports __builtin_expect. */ -#undef HAVE_BUILTIN_EXPECT - -/* Define to 1 if you have the header file. */ -#undef HAVE_BYTESWAP_H - -/* Define to 1 if you have the header file. */ -#undef HAVE_DLFCN_H - -/* Use the gflags package for command-line parsing. */ -#undef HAVE_GFLAGS - -/* Defined when Google Test is available. */ -#undef HAVE_GTEST - -/* Define to 1 if you have the header file. */ -#undef HAVE_INTTYPES_H - -/* Define to 1 if you have the `fastlz' library (-lfastlz). */ -#undef HAVE_LIBFASTLZ - -/* Define to 1 if you have the `lzf' library (-llzf). */ -#undef HAVE_LIBLZF - -/* Define to 1 if you have the `lzo2' library (-llzo2). */ -#undef HAVE_LIBLZO2 - -/* Define to 1 if you have the `quicklz' library (-lquicklz). */ -#undef HAVE_LIBQUICKLZ - -/* Define to 1 if you have the `z' library (-lz). */ -#undef HAVE_LIBZ - -/* Define to 1 if you have the header file. */ -#undef HAVE_MEMORY_H - -/* Define to 1 if you have the header file. */ -#undef HAVE_STDDEF_H - -/* Define to 1 if you have the header file. */ -#undef HAVE_STDINT_H - -/* Define to 1 if you have the header file. */ -#undef HAVE_STDLIB_H - -/* Define to 1 if you have the header file. */ -#undef HAVE_STRINGS_H - -/* Define to 1 if you have the header file. */ -#undef HAVE_STRING_H - -/* Define to 1 if you have the header file. */ -#undef HAVE_SYS_BYTESWAP_H - -/* Define to 1 if you have the header file. */ -#undef HAVE_SYS_ENDIAN_H - -/* Define to 1 if you have the header file. */ -#undef HAVE_SYS_MMAN_H - -/* Define to 1 if you have the header file. */ -#undef HAVE_SYS_RESOURCE_H - -/* Define to 1 if you have the header file. */ -#undef HAVE_SYS_STAT_H - -/* Define to 1 if you have the header file. */ -#undef HAVE_SYS_TIME_H - -/* Define to 1 if you have the header file. */ -#undef HAVE_SYS_TYPES_H - -/* Define to 1 if you have the header file. */ -#undef HAVE_UNISTD_H - -/* Define to 1 if you have the header file. */ -#undef HAVE_WINDOWS_H - -/* Define to the sub-directory in which libtool stores uninstalled libraries. - */ -#undef LT_OBJDIR - -/* Name of package */ -#undef PACKAGE - -/* Define to the address where bug reports for this package should be sent. */ -#undef PACKAGE_BUGREPORT - -/* Define to the full name of this package. */ -#undef PACKAGE_NAME - -/* Define to the full name and version of this package. */ -#undef PACKAGE_STRING - -/* Define to the one symbol short name of this package. */ -#undef PACKAGE_TARNAME - -/* Define to the home page for this package. */ -#undef PACKAGE_URL - -/* Define to the version of this package. */ -#undef PACKAGE_VERSION - -/* Define to 1 if you have the ANSI C header files. */ -#undef STDC_HEADERS - -/* Version number of package */ -#undef VERSION - -/* Define WORDS_BIGENDIAN to 1 if your processor stores words with the most - significant byte first (like Motorola and SPARC, unlike Intel). */ -#if defined AC_APPLE_UNIVERSAL_BUILD -# if defined __BIG_ENDIAN__ -# define WORDS_BIGENDIAN 1 -# endif -#else -# ifndef WORDS_BIGENDIAN -# undef WORDS_BIGENDIAN -# endif -#endif http://git-wip-us.apache.org/repos/asf/couchdb/blob/1eb889b2/src/snappy/google-snappy/snappy-internal.h ---------------------------------------------------------------------- diff --git a/src/snappy/google-snappy/snappy-internal.h b/src/snappy/google-snappy/snappy-internal.h deleted file mode 100644 index c99d331..0000000 --- a/src/snappy/google-snappy/snappy-internal.h +++ /dev/null @@ -1,150 +0,0 @@ -// Copyright 2008 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. -// -// Internals shared between the Snappy implementation and its unittest. - -#ifndef UTIL_SNAPPY_SNAPPY_INTERNAL_H_ -#define UTIL_SNAPPY_SNAPPY_INTERNAL_H_ - -#include "snappy-stubs-internal.h" - -namespace snappy { -namespace internal { - -class WorkingMemory { - public: - WorkingMemory() : large_table_(NULL) { } - ~WorkingMemory() { delete[] large_table_; } - - // Allocates and clears a hash table using memory in "*this", - // stores the number of buckets in "*table_size" and returns a pointer to - // the base of the hash table. - uint16* GetHashTable(size_t input_size, int* table_size); - - private: - uint16 small_table_[1<<10]; // 2KB - uint16* large_table_; // Allocated only when needed - - DISALLOW_COPY_AND_ASSIGN(WorkingMemory); -}; - -// Flat array compression that does not emit the "uncompressed length" -// prefix. Compresses "input" string to the "*op" buffer. -// -// REQUIRES: "input_length <= kBlockSize" -// REQUIRES: "op" points to an array of memory that is at least -// "MaxCompressedLength(input_length)" 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". -char* CompressFragment(const char* input, - size_t input_length, - char* op, - uint16* table, - const int table_size); - -// 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(ARCH_K8) -static inline int FindMatchLength(const char* s1, - const char* s2, - const char* s2_limit) { - assert(s2_limit >= s2); - int matched = 0; - - // 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 (PREDICT_TRUE(s2 <= s2_limit - 8)) { - if (PREDICT_FALSE(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. - uint64 x = UNALIGNED_LOAD64(s2) ^ UNALIGNED_LOAD64(s1 + matched); - int matching_bits = Bits::FindLSBSetNonZero64(x); - matched += matching_bits >> 3; - return matched; - } - } - while (PREDICT_TRUE(s2 < s2_limit)) { - if (PREDICT_TRUE(s1[matched] == *s2)) { - ++s2; - ++matched; - } else { - return matched; - } - } - return matched; -} -#else -static inline int FindMatchLength(const char* s1, - const char* s2, - const char* s2_limit) { - // Implementation based on the x86-64 version, above. - assert(s2_limit >= s2); - int matched = 0; - - while (s2 <= s2_limit - 4 && - UNALIGNED_LOAD32(s2) == UNALIGNED_LOAD32(s1 + matched)) { - s2 += 4; - matched += 4; - } - if (LittleEndian::IsLittleEndian() && s2 <= s2_limit - 4) { - uint32 x = UNALIGNED_LOAD32(s2) ^ UNALIGNED_LOAD32(s1 + matched); - int matching_bits = Bits::FindLSBSetNonZero(x); - matched += matching_bits >> 3; - } else { - while ((s2 < s2_limit) && (s1[matched] == *s2)) { - ++s2; - ++matched; - } - } - return matched; -} -#endif - -} // end namespace internal -} // end namespace snappy - -#endif // UTIL_SNAPPY_SNAPPY_INTERNAL_H_ http://git-wip-us.apache.org/repos/asf/couchdb/blob/1eb889b2/src/snappy/google-snappy/snappy-sinksource.cc ---------------------------------------------------------------------- diff --git a/src/snappy/google-snappy/snappy-sinksource.cc b/src/snappy/google-snappy/snappy-sinksource.cc deleted file mode 100644 index 5844552..0000000 --- a/src/snappy/google-snappy/snappy-sinksource.cc +++ /dev/null @@ -1,71 +0,0 @@ -// Copyright 2011 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. - -#include - -#include "snappy-sinksource.h" - -namespace snappy { - -Source::~Source() { } - -Sink::~Sink() { } - -char* Sink::GetAppendBuffer(size_t length, char* scratch) { - return scratch; -} - -ByteArraySource::~ByteArraySource() { } - -size_t ByteArraySource::Available() const { return left_; } - -const char* ByteArraySource::Peek(size_t* len) { - *len = left_; - return ptr_; -} - -void ByteArraySource::Skip(size_t n) { - left_ -= n; - ptr_ += n; -} - -UncheckedByteArraySink::~UncheckedByteArraySink() { } - -void UncheckedByteArraySink::Append(const char* data, size_t n) { - // Do no copying if the caller filled in the result of GetAppendBuffer() - if (data != dest_) { - memcpy(dest_, data, n); - } - dest_ += n; -} - -char* UncheckedByteArraySink::GetAppendBuffer(size_t len, char* scratch) { - return dest_; -} - -} http://git-wip-us.apache.org/repos/asf/couchdb/blob/1eb889b2/src/snappy/google-snappy/snappy-sinksource.h ---------------------------------------------------------------------- diff --git a/src/snappy/google-snappy/snappy-sinksource.h b/src/snappy/google-snappy/snappy-sinksource.h deleted file mode 100644 index faabfa1..0000000 --- a/src/snappy/google-snappy/snappy-sinksource.h +++ /dev/null @@ -1,137 +0,0 @@ -// Copyright 2011 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. - -#ifndef UTIL_SNAPPY_SNAPPY_SINKSOURCE_H_ -#define UTIL_SNAPPY_SNAPPY_SINKSOURCE_H_ - -#include - - -namespace snappy { - -// A Sink is an interface that consumes a sequence of bytes. -class Sink { - public: - Sink() { } - virtual ~Sink(); - - // Append "bytes[0,n-1]" to this. - virtual void Append(const char* bytes, size_t n) = 0; - - // Returns a writable buffer of the specified length for appending. - // May return a pointer to the caller-owned scratch buffer which - // must have at least the indicated length. The returned buffer is - // only valid until the next operation on this Sink. - // - // After writing at most "length" bytes, call Append() with the - // pointer returned from this function and the number of bytes - // written. Many Append() implementations will avoid copying - // bytes if this function returned an internal buffer. - // - // If a non-scratch buffer is returned, the caller may only pass a - // prefix of it to Append(). That is, it is not correct to pass an - // interior pointer of the returned array to Append(). - // - // The default implementation always returns the scratch buffer. - virtual char* GetAppendBuffer(size_t length, char* scratch); - - - private: - // No copying - Sink(const Sink&); - void operator=(const Sink&); -}; - -// A Source is an interface that yields a sequence of bytes -class Source { - public: - Source() { } - virtual ~Source(); - - // Return the number of bytes left to read from the source - virtual size_t Available() const = 0; - - // Peek at the next flat region of the source. Does not reposition - // the source. The returned region is empty iff Available()==0. - // - // Returns a pointer to the beginning of the region and store its - // length in *len. - // - // The returned region is valid until the next call to Skip() or - // until this object is destroyed, whichever occurs first. - // - // The returned region may be larger than Available() (for example - // if this ByteSource is a view on a substring of a larger source). - // The caller is responsible for ensuring that it only reads the - // Available() bytes. - virtual const char* Peek(size_t* len) = 0; - - // Skip the next n bytes. Invalidates any buffer returned by - // a previous call to Peek(). - // REQUIRES: Available() >= n - virtual void Skip(size_t n) = 0; - - private: - // No copying - Source(const Source&); - void operator=(const Source&); -}; - -// A Source implementation that yields the contents of a flat array -class ByteArraySource : public Source { - public: - ByteArraySource(const char* p, size_t n) : ptr_(p), left_(n) { } - virtual ~ByteArraySource(); - virtual size_t Available() const; - virtual const char* Peek(size_t* len); - virtual void Skip(size_t n); - private: - const char* ptr_; - size_t left_; -}; - -// A Sink implementation that writes to a flat array without any bound checks. -class UncheckedByteArraySink : public Sink { - public: - explicit UncheckedByteArraySink(char* dest) : dest_(dest) { } - virtual ~UncheckedByteArraySink(); - virtual void Append(const char* data, size_t n); - virtual char* GetAppendBuffer(size_t len, char* scratch); - - // Return the current output pointer so that a caller can see how - // many bytes were produced. - // Note: this is not a Sink method. - char* CurrentDestination() const { return dest_; } - private: - char* dest_; -}; - - -} - -#endif // UTIL_SNAPPY_SNAPPY_SINKSOURCE_H_ http://git-wip-us.apache.org/repos/asf/couchdb/blob/1eb889b2/src/snappy/google-snappy/snappy-stubs-internal.cc ---------------------------------------------------------------------- diff --git a/src/snappy/google-snappy/snappy-stubs-internal.cc b/src/snappy/google-snappy/snappy-stubs-internal.cc deleted file mode 100644 index 6ed3343..0000000 --- a/src/snappy/google-snappy/snappy-stubs-internal.cc +++ /dev/null @@ -1,42 +0,0 @@ -// Copyright 2011 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. - -#include -#include - -#include "snappy-stubs-internal.h" - -namespace snappy { - -void Varint::Append32(string* s, uint32 value) { - char buf[Varint::kMax32]; - const char* p = Varint::Encode32(buf, value); - s->append(buf, p - buf); -} - -} // namespace snappy