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Diffstat (limited to 'internal/ceres/collections_port.h')
| -rw-r--r-- | internal/ceres/collections_port.h | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/internal/ceres/collections_port.h b/internal/ceres/collections_port.h new file mode 100644 index 0000000..063b6d3 --- /dev/null +++ b/internal/ceres/collections_port.h @@ -0,0 +1,167 @@ +// Ceres Solver - A fast non-linear least squares minimizer +// Copyright 2010, 2011, 2012 Google Inc. All rights reserved. +// http://code.google.com/p/ceres-solver/ +// +// 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. +// +// Author: keir@google.com (Keir Mierle) +// +// Portable HashMap and HashSet, and a specialized overload for hashing pairs. + +#ifndef CERES_INTERNAL_COLLECTIONS_PORT_H_ +#define CERES_INTERNAL_COLLECTIONS_PORT_H_ + +#if defined(CERES_NO_TR1) +# include <map> +# include <set> +#else +# if defined(_MSC_VER) +# include <unordered_map> +# include <unordered_set> +# else +# include <tr1/unordered_map> +# include <tr1/unordered_set> +# endif +#endif +#include <utility> +#include "ceres/integral_types.h" +#include "ceres/internal/port.h" + +// Some systems don't have access to TR1. In that case, substitute the hash +// map/set with normal map/set. The price to pay is slightly slower speed for +// some operations. +#if defined(CERES_NO_TR1) + +namespace ceres { +namespace internal { + +template<typename K, typename V> +struct HashMap : map<K, V> {}; + +template<typename K> +struct HashSet : set<K> {}; + +} // namespace internal +} // namespace ceres + +#else + +namespace ceres { +namespace internal { + +template<typename K, typename V> +struct HashMap : std::tr1::unordered_map<K, V> {}; + +template<typename K> +struct HashSet : std::tr1::unordered_set<K> {}; + +#ifdef _WIN32 +#define GG_LONGLONG(x) x##I64 +#define GG_ULONGLONG(x) x##UI64 +#else +#define GG_LONGLONG(x) x##LL +#define GG_ULONGLONG(x) x##ULL +#endif + +// The hash function is due to Bob Jenkins (see +// http://burtleburtle.net/bob/hash/index.html). Each mix takes 36 instructions, +// in 18 cycles if you're lucky. On x86 architectures, this requires 45 +// instructions in 27 cycles, if you're lucky. +// +// 32bit version +inline void hash_mix(uint32& a, uint32& b, uint32& c) { + a -= b; a -= c; a ^= (c>>13); + b -= c; b -= a; b ^= (a<<8); + c -= a; c -= b; c ^= (b>>13); + a -= b; a -= c; a ^= (c>>12); + b -= c; b -= a; b ^= (a<<16); + c -= a; c -= b; c ^= (b>>5); + a -= b; a -= c; a ^= (c>>3); + b -= c; b -= a; b ^= (a<<10); + c -= a; c -= b; c ^= (b>>15); +} + +// 64bit version +inline void hash_mix(uint64& a, uint64& b, uint64& c) { + a -= b; a -= c; a ^= (c>>43); + b -= c; b -= a; b ^= (a<<9); + c -= a; c -= b; c ^= (b>>8); + a -= b; a -= c; a ^= (c>>38); + b -= c; b -= a; b ^= (a<<23); + c -= a; c -= b; c ^= (b>>5); + a -= b; a -= c; a ^= (c>>35); + b -= c; b -= a; b ^= (a<<49); + c -= a; c -= b; c ^= (b>>11); +} + +inline uint32 Hash32NumWithSeed(uint32 num, uint32 c) { + // The golden ratio; an arbitrary value. + uint32 b = 0x9e3779b9UL; + hash_mix(num, b, c); + return c; +} + +inline uint64 Hash64NumWithSeed(uint64 num, uint64 c) { + // More of the golden ratio. + uint64 b = GG_ULONGLONG(0xe08c1d668b756f82); + hash_mix(num, b, c); + return c; +} + +} // namespace internal +} // namespace ceres + +// Since on some platforms this is a doubly-nested namespace (std::tr1) and +// others it is not, the entire namespace line must be in a macro. +CERES_HASH_NAMESPACE_START + +// The outrageously annoying specializations below are for portability reasons. +// In short, it's not possible to have two overloads of hash<pair<T1, T2> + +// Hasher for STL pairs. Requires hashers for both members to be defined. +template<typename T> +struct hash<pair<T, T> > { + size_t operator()(const pair<T, T>& p) const { + size_t h1 = hash<T>()(p.first); + size_t h2 = hash<T>()(p.second); + // The decision below is at compile time + return (sizeof(h1) <= sizeof(ceres::internal::uint32)) ? + ceres::internal::Hash32NumWithSeed(h1, h2) : + ceres::internal::Hash64NumWithSeed(h1, h2); + } + // Less than operator for MSVC. + bool operator()(const pair<T, T>& a, + const pair<T, T>& b) const { + return a < b; + } + static const size_t bucket_size = 4; // These are required by MSVC + static const size_t min_buckets = 8; // 4 and 8 are defaults. +}; + +CERES_HASH_NAMESPACE_END + +#endif // CERES_NO_TR1 + +#endif // CERES_INTERNAL_COLLECTIONS_PORT_H_ |