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Diffstat (limited to 'src/google/protobuf/stubs/map-util.h')
-rw-r--r-- | src/google/protobuf/stubs/map-util.h | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/src/google/protobuf/stubs/map-util.h b/src/google/protobuf/stubs/map-util.h new file mode 100644 index 0000000..f5c9d6b --- /dev/null +++ b/src/google/protobuf/stubs/map-util.h @@ -0,0 +1,119 @@ +// Protocol Buffers - Google's data interchange format +// Copyright 2008 Google Inc. All rights reserved. +// http://code.google.com/p/protobuf/ +// +// 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. + +// from google3/util/gtl/map-util.h +// Author: Anton Carver + +#ifndef GOOGLE_PROTOBUF_STUBS_MAP_UTIL_H__ +#define GOOGLE_PROTOBUF_STUBS_MAP_UTIL_H__ + +#include <google/protobuf/stubs/common.h> + +namespace google { +namespace protobuf { + +// Perform a lookup in a map or hash_map. +// If the key is present in the map then the value associated with that +// key is returned, otherwise the value passed as a default is returned. +template <class Collection> +const typename Collection::value_type::second_type& +FindWithDefault(const Collection& collection, + const typename Collection::value_type::first_type& key, + const typename Collection::value_type::second_type& value) { + typename Collection::const_iterator it = collection.find(key); + if (it == collection.end()) { + return value; + } + return it->second; +} + +// Perform a lookup in a map or hash_map. +// If the key is present a const pointer to the associated value is returned, +// otherwise a NULL pointer is returned. +template <class Collection> +const typename Collection::value_type::second_type* +FindOrNull(const Collection& collection, + const typename Collection::value_type::first_type& key) { + typename Collection::const_iterator it = collection.find(key); + if (it == collection.end()) { + return 0; + } + return &it->second; +} + +// Perform a lookup in a map or hash_map whose values are pointers. +// If the key is present a const pointer to the associated value is returned, +// otherwise a NULL pointer is returned. +// This function does not distinguish between a missing key and a key mapped +// to a NULL value. +template <class Collection> +const typename Collection::value_type::second_type +FindPtrOrNull(const Collection& collection, + const typename Collection::value_type::first_type& key) { + typename Collection::const_iterator it = collection.find(key); + if (it == collection.end()) { + return 0; + } + return it->second; +} + +// Change the value associated with a particular key in a map or hash_map. +// If the key is not present in the map the key and value are inserted, +// otherwise the value is updated to be a copy of the value provided. +// True indicates that an insert took place, false indicates an update. +template <class Collection, class Key, class Value> +bool InsertOrUpdate(Collection * const collection, + const Key& key, const Value& value) { + pair<typename Collection::iterator, bool> ret = + collection->insert(typename Collection::value_type(key, value)); + if (!ret.second) { + // update + ret.first->second = value; + return false; + } + return true; +} + +// Insert a new key and value into a map or hash_map. +// If the key is not present in the map the key and value are +// inserted, otherwise nothing happens. True indicates that an insert +// took place, false indicates the key was already present. +template <class Collection, class Key, class Value> +bool InsertIfNotPresent(Collection * const collection, + const Key& key, const Value& value) { + pair<typename Collection::iterator, bool> ret = + collection->insert(typename Collection::value_type(key, value)); + return ret.second; +} + +} // namespace protobuf +} // namespace google + +#endif // GOOGLE_PROTOBUF_STUBS_MAP_UTIL_H__ |