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Diffstat (limited to 'src/google/protobuf/stubs/hash.h')
-rw-r--r-- | src/google/protobuf/stubs/hash.h | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/src/google/protobuf/stubs/hash.h b/src/google/protobuf/stubs/hash.h new file mode 100644 index 00000000..a62b3f6e --- /dev/null +++ b/src/google/protobuf/stubs/hash.h @@ -0,0 +1,123 @@ +// Protocol Buffers - Google's data interchange format +// Copyright 2008 Google Inc. +// http://code.google.com/p/protobuf/ +// +// 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. + +// Author: kenton@google.com (Kenton Varda) +// +// Deals with the fact that hash_map is not defined everywhere. + +#ifndef GOOGLE_PROTOBUF_STUBS_HASH_H__ +#define GOOGLE_PROTOBUF_STUBS_HASH_H__ + +#include <string.h> +#include <google/protobuf/stubs/common.h> +#include "config.h" + +#if defined(HAVE_HASH_MAP) && defined(HAVE_HASH_SET) +#include HASH_MAP_H +#include HASH_SET_H +#else +// TODO(kenton): Deal with non-existence of hash_map somehow. Maybe emulate +// it with map? +#error "Your STL implementation lacks hash_map and/or hash_set." +#endif + +namespace google { +namespace protobuf { + +#ifdef _MSC_VER + +template <typename Key> +struct hash : public HASH_NAMESPACE::hash_compare<Key> { +}; + +// MSVC's hash_compare<const char*> hashes based on the string contents but +// compares based on the string pointer. WTF? +class CstringLess { + public: + inline bool operator()(const char* a, const char* b) const { + return strcmp(a, b) < 0; + } +}; + +template <> +struct hash<const char*> + : public HASH_NAMESPACE::hash_compare<const char*, CstringLess> { +}; + +template <typename Key, typename Data, + typename HashFcn = hash<Key>, + typename EqualKey = int > +class hash_map : public HASH_NAMESPACE::hash_map< + Key, Data, HashFcn> { +}; + +template <typename Key, + typename HashFcn = hash<Key>, + typename EqualKey = int > +class hash_set : public HASH_NAMESPACE::hash_set< + Key, HashFcn> { +}; + +#else + +template <typename Key> +struct hash : public HASH_NAMESPACE::hash<Key> { +}; + +template <typename Key> +struct hash<const Key*> { + inline size_t operator()(const Key* key) const { + return reinterpret_cast<size_t>(key); + } +}; + +template <> +struct hash<const char*> : public HASH_NAMESPACE::hash<const char*> { +}; + +template <typename Key, typename Data, + typename HashFcn = hash<Key>, + typename EqualKey = std::equal_to<Key> > +class hash_map : public HASH_NAMESPACE::hash_map< + Key, Data, HashFcn, EqualKey> { +}; + +template <typename Key, + typename HashFcn = hash<Key>, + typename EqualKey = std::equal_to<Key> > +class hash_set : public HASH_NAMESPACE::hash_set< + Key, HashFcn, EqualKey> { +}; + +#endif + +template <> +struct hash<string> { + inline size_t operator()(const string& key) const { + return hash<const char*>()(key.c_str()); + } + + static const size_t bucket_size = 4; + static const size_t min_buckets = 8; + inline size_t operator()(const string& a, const string& b) const { + return a < b; + } +}; + +} // namespace protobuf +} // namespace google + +#endif // GOOGLE_PROTOBUF_STUBS_HASH_H__ |