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Diffstat (limited to 'app/snappy/snappy-stubs-internal.h')
-rw-r--r-- | app/snappy/snappy-stubs-internal.h | 491 |
1 files changed, 0 insertions, 491 deletions
diff --git a/app/snappy/snappy-stubs-internal.h b/app/snappy/snappy-stubs-internal.h deleted file mode 100644 index 12393b62..00000000 --- a/app/snappy/snappy-stubs-internal.h +++ /dev/null @@ -1,491 +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. -// -// Various stubs for the open-source version of Snappy. - -#ifndef UTIL_SNAPPY_OPENSOURCE_SNAPPY_STUBS_INTERNAL_H_ -#define UTIL_SNAPPY_OPENSOURCE_SNAPPY_STUBS_INTERNAL_H_ - -#ifdef HAVE_CONFIG_H -#include "config.h" -#endif - -#include <string> - -#include <assert.h> -#include <stdlib.h> -#include <string.h> - -#ifdef HAVE_SYS_MMAN_H -#include <sys/mman.h> -#endif - -#include "snappy-stubs-public.h" - -#if defined(__x86_64__) - -// Enable 64-bit optimized versions of some routines. -#define ARCH_K8 1 - -#endif - -// Needed by OS X, among others. -#ifndef MAP_ANONYMOUS -#define MAP_ANONYMOUS MAP_ANON -#endif - -// Pull in std::min, std::ostream, and the likes. This is safe because this -// header file is never used from any public header files. -using namespace std; - -// The size of an array, if known at compile-time. -// Will give unexpected results if used on a pointer. -// We undefine it first, since some compilers already have a definition. -#ifdef ARRAYSIZE -#undef ARRAYSIZE -#endif -#define ARRAYSIZE(a) (sizeof(a) / sizeof(*(a))) - -// Static prediction hints. -#ifdef HAVE_BUILTIN_EXPECT -#define PREDICT_FALSE(x) (__builtin_expect(x, 0)) -#define PREDICT_TRUE(x) (__builtin_expect(!!(x), 1)) -#else -#define PREDICT_FALSE(x) x -#define PREDICT_TRUE(x) x -#endif - -// This is only used for recomputing the tag byte table used during -// decompression; for simplicity we just remove it from the open-source -// version (anyone who wants to regenerate it can just do the call -// themselves within main()). -#define DEFINE_bool(flag_name, default_value, description) \ - bool FLAGS_ ## flag_name = default_value -#define DECLARE_bool(flag_name) \ - extern bool FLAGS_ ## flag_name - -namespace snappy { - -static const uint32 kuint32max = static_cast<uint32>(0xFFFFFFFF); -static const int64 kint64max = static_cast<int64>(0x7FFFFFFFFFFFFFFFLL); - -// Potentially unaligned loads and stores. - -// x86 and PowerPC can simply do these loads and stores native. - -#if defined(__i386__) || defined(__x86_64__) || defined(__powerpc__) - -#define UNALIGNED_LOAD16(_p) (*reinterpret_cast<const uint16 *>(_p)) -#define UNALIGNED_LOAD32(_p) (*reinterpret_cast<const uint32 *>(_p)) -#define UNALIGNED_LOAD64(_p) (*reinterpret_cast<const uint64 *>(_p)) - -#define UNALIGNED_STORE16(_p, _val) (*reinterpret_cast<uint16 *>(_p) = (_val)) -#define UNALIGNED_STORE32(_p, _val) (*reinterpret_cast<uint32 *>(_p) = (_val)) -#define UNALIGNED_STORE64(_p, _val) (*reinterpret_cast<uint64 *>(_p) = (_val)) - -// ARMv7 and newer support native unaligned accesses, but only of 16-bit -// and 32-bit values (not 64-bit); older versions either raise a fatal signal, -// do an unaligned read and rotate the words around a bit, or do the reads very -// slowly (trip through kernel mode). There's no simple #define that says just -// “ARMv7 or higher”, so we have to filter away all ARMv5 and ARMv6 -// sub-architectures. -// -// This is a mess, but there's not much we can do about it. - -#elif defined(__arm__) && \ - !defined(__ARM_ARCH_4__) && \ - !defined(__ARM_ARCH_4T__) && \ - !defined(__ARM_ARCH_5__) && \ - !defined(__ARM_ARCH_5T__) && \ - !defined(__ARM_ARCH_5TE__) && \ - !defined(__ARM_ARCH_5TEJ__) && \ - !defined(__ARM_ARCH_6__) && \ - !defined(__ARM_ARCH_6J__) && \ - !defined(__ARM_ARCH_6K__) && \ - !defined(__ARM_ARCH_6Z__) && \ - !defined(__ARM_ARCH_6ZK__) && \ - !defined(__ARM_ARCH_6T2__) - -#define UNALIGNED_LOAD16(_p) (*reinterpret_cast<const uint16 *>(_p)) -#define UNALIGNED_LOAD32(_p) (*reinterpret_cast<const uint32 *>(_p)) - -#define UNALIGNED_STORE16(_p, _val) (*reinterpret_cast<uint16 *>(_p) = (_val)) -#define UNALIGNED_STORE32(_p, _val) (*reinterpret_cast<uint32 *>(_p) = (_val)) - -// TODO(user): NEON supports unaligned 64-bit loads and stores. -// See if that would be more efficient on platforms supporting it, -// at least for copies. - -inline uint64 UNALIGNED_LOAD64(const void *p) { - uint64 t; - memcpy(&t, p, sizeof t); - return t; -} - -inline void UNALIGNED_STORE64(void *p, uint64 v) { - memcpy(p, &v, sizeof v); -} - -#else - -// These functions are provided for architectures that don't support -// unaligned loads and stores. - -inline uint16 UNALIGNED_LOAD16(const void *p) { - uint16 t; - memcpy(&t, p, sizeof t); - return t; -} - -inline uint32 UNALIGNED_LOAD32(const void *p) { - uint32 t; - memcpy(&t, p, sizeof t); - return t; -} - -inline uint64 UNALIGNED_LOAD64(const void *p) { - uint64 t; - memcpy(&t, p, sizeof t); - return t; -} - -inline void UNALIGNED_STORE16(void *p, uint16 v) { - memcpy(p, &v, sizeof v); -} - -inline void UNALIGNED_STORE32(void *p, uint32 v) { - memcpy(p, &v, sizeof v); -} - -inline void UNALIGNED_STORE64(void *p, uint64 v) { - memcpy(p, &v, sizeof v); -} - -#endif - -// This can be more efficient than UNALIGNED_LOAD64 + UNALIGNED_STORE64 -// on some platforms, in particular ARM. -inline void UnalignedCopy64(const void *src, void *dst) { - if (sizeof(void *) == 8) { - UNALIGNED_STORE64(dst, UNALIGNED_LOAD64(src)); - } else { - const char *src_char = reinterpret_cast<const char *>(src); - char *dst_char = reinterpret_cast<char *>(dst); - - UNALIGNED_STORE32(dst_char, UNALIGNED_LOAD32(src_char)); - UNALIGNED_STORE32(dst_char + 4, UNALIGNED_LOAD32(src_char + 4)); - } -} - -// The following guarantees declaration of the byte swap functions. -#ifdef WORDS_BIGENDIAN - -#ifdef HAVE_SYS_BYTEORDER_H -#include <sys/byteorder.h> -#endif - -#ifdef HAVE_SYS_ENDIAN_H -#include <sys/endian.h> -#endif - -#ifdef _MSC_VER -#include <stdlib.h> -#define bswap_16(x) _byteswap_ushort(x) -#define bswap_32(x) _byteswap_ulong(x) -#define bswap_64(x) _byteswap_uint64(x) - -#elif defined(__APPLE__) -// Mac OS X / Darwin features -#include <libkern/OSByteOrder.h> -#define bswap_16(x) OSSwapInt16(x) -#define bswap_32(x) OSSwapInt32(x) -#define bswap_64(x) OSSwapInt64(x) - -#elif defined(HAVE_BYTESWAP_H) -#include <byteswap.h> - -#elif defined(bswap32) -// FreeBSD defines bswap{16,32,64} in <sys/endian.h> (already #included). -#define bswap_16(x) bswap16(x) -#define bswap_32(x) bswap32(x) -#define bswap_64(x) bswap64(x) - -#elif defined(BSWAP_64) -// Solaris 10 defines BSWAP_{16,32,64} in <sys/byteorder.h> (already #included). -#define bswap_16(x) BSWAP_16(x) -#define bswap_32(x) BSWAP_32(x) -#define bswap_64(x) BSWAP_64(x) - -#else - -inline uint16 bswap_16(uint16 x) { - return (x << 8) | (x >> 8); -} - -inline uint32 bswap_32(uint32 x) { - x = ((x & 0xff00ff00UL) >> 8) | ((x & 0x00ff00ffUL) << 8); - return (x >> 16) | (x << 16); -} - -inline uint64 bswap_64(uint64 x) { - x = ((x & 0xff00ff00ff00ff00ULL) >> 8) | ((x & 0x00ff00ff00ff00ffULL) << 8); - x = ((x & 0xffff0000ffff0000ULL) >> 16) | ((x & 0x0000ffff0000ffffULL) << 16); - return (x >> 32) | (x << 32); -} - -#endif - -#endif // WORDS_BIGENDIAN - -// Convert to little-endian storage, opposite of network format. -// Convert x from host to little endian: x = LittleEndian.FromHost(x); -// convert x from little endian to host: x = LittleEndian.ToHost(x); -// -// Store values into unaligned memory converting to little endian order: -// LittleEndian.Store16(p, x); -// -// Load unaligned values stored in little endian converting to host order: -// x = LittleEndian.Load16(p); -class LittleEndian { - public: - // Conversion functions. -#ifdef WORDS_BIGENDIAN - - static uint16 FromHost16(uint16 x) { return bswap_16(x); } - static uint16 ToHost16(uint16 x) { return bswap_16(x); } - - static uint32 FromHost32(uint32 x) { return bswap_32(x); } - static uint32 ToHost32(uint32 x) { return bswap_32(x); } - - static bool IsLittleEndian() { return false; } - -#else // !defined(WORDS_BIGENDIAN) - - static uint16 FromHost16(uint16 x) { return x; } - static uint16 ToHost16(uint16 x) { return x; } - - static uint32 FromHost32(uint32 x) { return x; } - static uint32 ToHost32(uint32 x) { return x; } - - static bool IsLittleEndian() { return true; } - -#endif // !defined(WORDS_BIGENDIAN) - - // Functions to do unaligned loads and stores in little-endian order. - static uint16 Load16(const void *p) { - return ToHost16(UNALIGNED_LOAD16(p)); - } - - static void Store16(void *p, uint16 v) { - UNALIGNED_STORE16(p, FromHost16(v)); - } - - static uint32 Load32(const void *p) { - return ToHost32(UNALIGNED_LOAD32(p)); - } - - static void Store32(void *p, uint32 v) { - UNALIGNED_STORE32(p, FromHost32(v)); - } -}; - -// Some bit-manipulation functions. -class Bits { - public: - // Return floor(log2(n)) for positive integer n. Returns -1 iff n == 0. - static int Log2Floor(uint32 n); - - // Return the first set least / most significant bit, 0-indexed. Returns an - // undefined value if n == 0. FindLSBSetNonZero() is similar to ffs() except - // that it's 0-indexed. - static int FindLSBSetNonZero(uint32 n); - static int FindLSBSetNonZero64(uint64 n); - - private: - DISALLOW_COPY_AND_ASSIGN(Bits); -}; - -#ifdef HAVE_BUILTIN_CTZ - -inline int Bits::Log2Floor(uint32 n) { - return n == 0 ? -1 : 31 ^ __builtin_clz(n); -} - -inline int Bits::FindLSBSetNonZero(uint32 n) { - return __builtin_ctz(n); -} - -inline int Bits::FindLSBSetNonZero64(uint64 n) { - return __builtin_ctzll(n); -} - -#else // Portable versions. - -inline int Bits::Log2Floor(uint32 n) { - if (n == 0) - return -1; - int log = 0; - uint32 value = n; - for (int i = 4; i >= 0; --i) { - int shift = (1 << i); - uint32 x = value >> shift; - if (x != 0) { - value = x; - log += shift; - } - } - assert(value == 1); - return log; -} - -inline int Bits::FindLSBSetNonZero(uint32 n) { - int rc = 31; - for (int i = 4, shift = 1 << 4; i >= 0; --i) { - const uint32 x = n << shift; - if (x != 0) { - n = x; - rc -= shift; - } - shift >>= 1; - } - return rc; -} - -// FindLSBSetNonZero64() is defined in terms of FindLSBSetNonZero(). -inline int Bits::FindLSBSetNonZero64(uint64 n) { - const uint32 bottombits = static_cast<uint32>(n); - if (bottombits == 0) { - // Bottom bits are zero, so scan in top bits - return 32 + FindLSBSetNonZero(static_cast<uint32>(n >> 32)); - } else { - return FindLSBSetNonZero(bottombits); - } -} - -#endif // End portable versions. - -// Variable-length integer encoding. -class Varint { - public: - // Maximum lengths of varint encoding of uint32. - static const int kMax32 = 5; - - // Attempts to parse a varint32 from a prefix of the bytes in [ptr,limit-1]. - // Never reads a character at or beyond limit. If a valid/terminated varint32 - // was found in the range, stores it in *OUTPUT and returns a pointer just - // past the last byte of the varint32. Else returns NULL. On success, - // "result <= limit". - static const char* Parse32WithLimit(const char* ptr, const char* limit, - uint32* OUTPUT); - - // REQUIRES "ptr" points to a buffer of length sufficient to hold "v". - // EFFECTS Encodes "v" into "ptr" and returns a pointer to the - // byte just past the last encoded byte. - static char* Encode32(char* ptr, uint32 v); - - // EFFECTS Appends the varint representation of "value" to "*s". - static void Append32(string* s, uint32 value); -}; - -inline const char* Varint::Parse32WithLimit(const char* p, - const char* l, - uint32* OUTPUT) { - const unsigned char* ptr = reinterpret_cast<const unsigned char*>(p); - const unsigned char* limit = reinterpret_cast<const unsigned char*>(l); - uint32 b, result; - if (ptr >= limit) return NULL; - b = *(ptr++); result = b & 127; if (b < 128) goto done; - if (ptr >= limit) return NULL; - b = *(ptr++); result |= (b & 127) << 7; if (b < 128) goto done; - if (ptr >= limit) return NULL; - b = *(ptr++); result |= (b & 127) << 14; if (b < 128) goto done; - if (ptr >= limit) return NULL; - b = *(ptr++); result |= (b & 127) << 21; if (b < 128) goto done; - if (ptr >= limit) return NULL; - b = *(ptr++); result |= (b & 127) << 28; if (b < 16) goto done; - return NULL; // Value is too long to be a varint32 - done: - *OUTPUT = result; - return reinterpret_cast<const char*>(ptr); -} - -inline char* Varint::Encode32(char* sptr, uint32 v) { - // Operate on characters as unsigneds - unsigned char* ptr = reinterpret_cast<unsigned char*>(sptr); - static const int B = 128; - if (v < (1<<7)) { - *(ptr++) = v; - } else if (v < (1<<14)) { - *(ptr++) = v | B; - *(ptr++) = v>>7; - } else if (v < (1<<21)) { - *(ptr++) = v | B; - *(ptr++) = (v>>7) | B; - *(ptr++) = v>>14; - } else if (v < (1<<28)) { - *(ptr++) = v | B; - *(ptr++) = (v>>7) | B; - *(ptr++) = (v>>14) | B; - *(ptr++) = v>>21; - } else { - *(ptr++) = v | B; - *(ptr++) = (v>>7) | B; - *(ptr++) = (v>>14) | B; - *(ptr++) = (v>>21) | B; - *(ptr++) = v>>28; - } - return reinterpret_cast<char*>(ptr); -} - -// If you know the internal layout of the std::string in use, you can -// replace this function with one that resizes the string without -// filling the new space with zeros (if applicable) -- -// it will be non-portable but faster. -inline void STLStringResizeUninitialized(string* s, size_t new_size) { - s->resize(new_size); -} - -// Return a mutable char* pointing to a string's internal buffer, -// which may not be null-terminated. Writing through this pointer will -// modify the string. -// -// string_as_array(&str)[i] is valid for 0 <= i < str.size() until the -// next call to a string method that invalidates iterators. -// -// As of 2006-04, there is no standard-blessed way of getting a -// mutable reference to a string's internal buffer. However, issue 530 -// (http://www.open-std.org/JTC1/SC22/WG21/docs/lwg-defects.html#530) -// proposes this as the method. It will officially be part of the standard -// for C++0x. This should already work on all current implementations. -inline char* string_as_array(string* str) { - return str->empty() ? NULL : &*str->begin(); -} - -} // namespace snappy - -#endif // UTIL_SNAPPY_OPENSOURCE_SNAPPY_STUBS_INTERNAL_H_ |