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Posted to commits@couchdb.apache.org by da...@apache.org on 2014/02/05 00:44:54 UTC
[41/44] Remove src/snappy
http://git-wip-us.apache.org/repos/asf/couchdb/blob/350a7efd/src/snappy/c_src/google-snappy/snappy.cc
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diff --git a/src/snappy/c_src/google-snappy/snappy.cc b/src/snappy/c_src/google-snappy/snappy.cc
deleted file mode 100644
index 4d4eb42..0000000
--- a/src/snappy/c_src/google-snappy/snappy.cc
+++ /dev/null
@@ -1,1111 +0,0 @@
-// 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.
-
-#include "snappy.h"
-#include "snappy-internal.h"
-#include "snappy-sinksource.h"
-
-#include <stdio.h>
-
-#include <algorithm>
-#include <string>
-#include <vector>
-
-
-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
-// <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.
-
-namespace {
-
-const int kMaxIncrementCopyOverflow = 10;
-
-} // namespace
-
-static inline void IncrementalCopyFastPath(const char* src, char* op, int len) {
- while (op - src < 8) {
- UnalignedCopy64(src, op);
- len -= op - src;
- op += op - src;
- }
- while (len > 0) {
- UnalignedCopy64(src, op);
- 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) {
- UnalignedCopy64(literal, op);
- UnalignedCopy64(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++;
- }
- assert(count >= 1);
- assert(count <= 4);
- *base = LITERAL | ((59+count) << 2);
- }
- memcpy(op, literal, len);
- return op + len;
-}
-
-static inline char* EmitCopyLessThan64(char* op, size_t offset, int len) {
- DCHECK_LE(len, 64);
- DCHECK_GE(len, 4);
- DCHECK_LT(offset, 65536);
-
- if ((len < 12) && (offset < 2048)) {
- size_t 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, size_t 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);
- size_t 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(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 uint32.
-//
-// 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.
-
-#ifdef ARCH_K8
-
-typedef uint64 EightBytesReference;
-
-static inline EightBytesReference GetEightBytesAt(const char* ptr) {
- return UNALIGNED_LOAD64(ptr);
-}
-
-static inline uint32 GetUint32AtOffset(uint64 v, int offset) {
- DCHECK_GE(offset, 0);
- DCHECK_LE(offset, 4);
- return v >> (LittleEndian::IsLittleEndian() ? 8 * offset : 32 - 8 * offset);
-}
-
-#else
-
-typedef const char* EightBytesReference;
-
-static inline EightBytesReference GetEightBytesAt(const char* ptr) {
- return ptr;
-}
-
-static inline uint32 GetUint32AtOffset(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".
-namespace internal {
-char* CompressFragment(const char* input,
- 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(static_cast<int>(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 size_t 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.
- EightBytesReference input_bytes;
- 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;
- size_t 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 = GetEightBytesAt(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, size_t length);
-// bool AppendFromSelf(uint32 offset, size_t length);
-//
-// // The difference between TryFastAppend and Append is that TryFastAppend
-// // is allowed to read up to <available> bytes from the input buffer,
-// // whereas Append is allowed to read <length>.
-// //
-// // Also, TryFastAppend is allowed to return false, declining the append,
-// // without it being a fatal error -- just "return false" would be
-// // a perfectly legal implementation of TryFastAppend. The intention
-// // is for TryFastAppend to allow a fast path in the common case of
-// // a small append.
-// //
-// // NOTE(user): TryFastAppend must always return decline (return false)
-// // if <length> is 61 or more, as in this case the literal length is not
-// // decoded fully. In practice, this should not be a big problem,
-// // as it is unlikely that one would implement a fast path accepting
-// // this much data.
-// bool TryFastAppend(const char* ip, size_t available, size_t length);
-// };
-
-// -----------------------------------------------------------------------
-// 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]);
- }
-}
-#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<const unsigned char*>(ip));
- reader_->Skip(1);
- *result |= static_cast<uint32>(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 <class Writer>
- void DecompressAllTags(Writer* writer) {
- const char* ip = 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 (ip_limit_ - ip < 5) { \
- ip_ = ip; \
- if (!RefillTag()) return; \
- ip = ip_; \
- }
-
- MAYBE_REFILL();
- for ( ;; ) {
- const unsigned char c = *(reinterpret_cast<const unsigned char*>(ip++));
-
- if ((c & 0x3) == LITERAL) {
- size_t literal_length = (c >> 2) + 1u;
- if (writer->TryFastAppend(ip, ip_limit_ - ip, literal_length)) {
- DCHECK_LT(literal_length, 61);
- ip += literal_length;
- MAYBE_REFILL();
- continue;
- }
- if (PREDICT_FALSE(literal_length >= 61)) {
- // Long literal.
- const size_t literal_length_length = literal_length - 60;
- literal_length =
- (LittleEndian::Load32(ip) & wordmask[literal_length_length]) + 1;
- ip += literal_length_length;
- }
-
- size_t avail = ip_limit_ - ip;
- while (avail < literal_length) {
- if (!writer->Append(ip, avail)) 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;
- }
- if (!writer->Append(ip, literal_length)) {
- return;
- }
- ip += literal_length;
- MAYBE_REFILL();
- } else {
- const uint32 entry = char_table[c];
- const uint32 trailer = LittleEndian::Load32(ip) & wordmask[entry >> 11];
- const uint32 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 uint32 copy_offset = entry & 0x700;
- if (!writer->AppendFromSelf(copy_offset + trailer, length)) {
- return;
- }
- MAYBE_REFILL();
- }
- }
-
-#undef MAYBE_REFILL
- }
-};
-
-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<const unsigned char*>(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<uint32>(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 <typename Writer>
-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;
- return InternalUncompressAllTags(
- &decompressor, writer, uncompressed_len, max_len);
-}
-
-template <typename Writer>
-static bool InternalUncompressAllTags(SnappyDecompressor* decompressor,
- Writer* writer,
- uint32 uncompressed_len,
- uint32 max_len) {
- // Protect against possible DoS attack
- if (static_cast<uint64>(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;
- size_t 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 size_t num_to_read = min(N, kBlockSize);
- size_t bytes_read = fragment_size;
-
- size_t 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<size_t>(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, size_t len) {
- char* op = op_;
- const size_t space_left = op_limit_ - op;
- if (space_left < len) {
- return false;
- }
- memcpy(op, ip, len);
- op_ = op + len;
- return true;
- }
-
- inline bool TryFastAppend(const char* ip, size_t available, size_t len) {
- char* op = op_;
- const size_t space_left = op_limit_ - op;
- if (len <= 16 && available >= 16 && space_left >= 16) {
- // Fast path, used for the majority (about 95%) of invocations.
- UnalignedCopy64(ip, op);
- UnalignedCopy64(ip + 8, op + 8);
- op_ = op + len;
- return true;
- } else {
- return false;
- }
- }
-
- inline bool AppendFromSelf(size_t offset, size_t len) {
- char* op = op_;
- const size_t 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.
- UnalignedCopy64(op - offset, op);
- UnalignedCopy64(op - offset + 8, op + 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<uint64>(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, size_t len) {
- produced_ += len;
- return produced_ <= expected_;
- }
- inline bool TryFastAppend(const char* ip, size_t available, size_t length) {
- return false;
- }
- inline bool AppendFromSelf(size_t offset, size_t 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/350a7efd/src/snappy/c_src/google-snappy/snappy.h
----------------------------------------------------------------------
diff --git a/src/snappy/c_src/google-snappy/snappy.h b/src/snappy/c_src/google-snappy/snappy.h
deleted file mode 100644
index 8c2075f..0000000
--- a/src/snappy/c_src/google-snappy/snappy.h
+++ /dev/null
@@ -1,155 +0,0 @@
-// 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 <stddef.h>
-#include <string>
-
-#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 size_t kBlockSize = 1 << kBlockLog;
-
- static const int kMaxHashTableBits = 14;
- static const size_t kMaxHashTableSize = 1 << kMaxHashTableBits;
-
-} // end namespace snappy
-
-
-#endif // UTIL_SNAPPY_SNAPPY_H__
http://git-wip-us.apache.org/repos/asf/couchdb/blob/350a7efd/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
deleted file mode 100644
index ae28d91..0000000
--- a/src/snappy/c_src/snappy_nif.cc
+++ /dev/null
@@ -1,265 +0,0 @@
-/**
- * Copyright 2011, Filipe David Manana <fd...@apache.org>
- * 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 <iostream>
-#include <cstring>
-
-#include "erl_nif_compat.h"
-#include "google-snappy/snappy.h"
-#include "google-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<char *>(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/350a7efd/src/snappy/src/snappy.app.src
----------------------------------------------------------------------
diff --git a/src/snappy/src/snappy.app.src b/src/snappy/src/snappy.app.src
deleted file mode 100644
index 9f3f9a3..0000000
--- a/src/snappy/src/snappy.app.src
+++ /dev/null
@@ -1,12 +0,0 @@
-{application, snappy,
- [
- {description, "snappy compressor/decompressor Erlang NIF wrapper"},
- {vsn, git},
- {registered, []},
- {applications, [
- kernel,
- stdlib
- ]},
- {env, []},
- {modules, [snappy]}
- ]}.
http://git-wip-us.apache.org/repos/asf/couchdb/blob/350a7efd/src/snappy/src/snappy.erl
----------------------------------------------------------------------
diff --git a/src/snappy/src/snappy.erl b/src/snappy/src/snappy.erl
deleted file mode 100644
index 7d3d36a..0000000
--- a/src/snappy/src/snappy.erl
+++ /dev/null
@@ -1,56 +0,0 @@
-%% Copyright 2011, Filipe David Manana <fd...@apache.org>
-%% 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.
-
--module(snappy).
-
--export([compress/1, decompress/1]).
--export([uncompressed_length/1, is_valid/1]).
-
--on_load(init/0).
-
-
-init() ->
- SoName = case code:priv_dir(?MODULE) of
- {error, bad_name} ->
- case filelib:is_dir(filename:join(["..", "priv"])) of
- true ->
- filename:join(["..", "priv", "snappy_nif"]);
- false ->
- filename:join(["priv", "snappy_nif"])
- end;
- Dir ->
- filename:join(Dir, "snappy_nif")
- end,
- (catch erlang:load_nif(SoName, 0)),
- case erlang:system_info(otp_release) of
- "R13B03" -> true;
- _ -> ok
- end.
-
-
-compress(_IoList) ->
- exit(snappy_nif_not_loaded).
-
-
-decompress(_IoList) ->
- exit(snappy_nif_not_loaded).
-
-
-uncompressed_length(_IoList) ->
- exit(snappy_nif_not_loaded).
-
-
-is_valid(_IoList) ->
- exit(snappy_nif_not_loaded).