map-util.h revision ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16
15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Protocol Buffers - Google's data interchange format 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright 2008 Google Inc. All rights reserved. 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// http://code.google.com/p/protobuf/ 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Redistribution and use in source and binary forms, with or without 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// modification, are permitted provided that the following conditions are 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// met: 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// * Redistributions of source code must retain the above copyright 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// notice, this list of conditions and the following disclaimer. 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// * Redistributions in binary form must reproduce the above 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// copyright notice, this list of conditions and the following disclaimer 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// in the documentation and/or other materials provided with the 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// distribution. 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// * Neither the name of Google Inc. nor the names of its 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// contributors may be used to endorse or promote products derived from 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// this software without specific prior written permission. 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// from google3/util/gtl/map-util.h 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Author: Anton Carver 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifndef GOOGLE_PROTOBUF_STUBS_MAP_UTIL_H__ 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#define GOOGLE_PROTOBUF_STUBS_MAP_UTIL_H__ 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <google/protobuf/stubs/common.h> 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace google { 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace protobuf { 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Perform a lookup in a map or hash_map. 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// If the key is present in the map then the value associated with that 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// key is returned, otherwise the value passed as a default is returned. 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)template <class Collection> 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)const typename Collection::value_type::second_type& 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)FindWithDefault(const Collection& collection, 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const typename Collection::value_type::first_type& key, 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const typename Collection::value_type::second_type& value) { 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) typename Collection::const_iterator it = collection.find(key); 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (it == collection.end()) { 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return value; 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return it->second; 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Perform a lookup in a map or hash_map. 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// If the key is present a const pointer to the associated value is returned, 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// otherwise a NULL pointer is returned. 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)template <class Collection> 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)const typename Collection::value_type::second_type* 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)FindOrNull(const Collection& collection, 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const typename Collection::value_type::first_type& key) { 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) typename Collection::const_iterator it = collection.find(key); 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (it == collection.end()) { 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return 0; 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return &it->second; 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 71ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch// Perform a lookup in a map or hash_map, assuming that the key exists. 72ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch// Crash if it does not. 73ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch// 74ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch// This is intended as a replacement for operator[] as an rvalue (for reading) 75ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch// when the key is guaranteed to exist. 76ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch// 77ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch// operator[] is discouraged for several reasons: 78ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch// * It has a side-effect of inserting missing keys 79ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch// * It is not thread-safe (even when it is not inserting, it can still 80ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch// choose to resize the underlying storage) 81ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch// * It invalidates iterators (when it chooses to resize) 82ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch// * It default constructs a value object even if it doesn't need to 83ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch// 84ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch// This version assumes the key is printable, and includes it in the fatal log 85ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch// message. 86ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdochtemplate <class Collection> 87ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdochconst typename Collection::value_type::second_type& 88ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben MurdochFindOrDie(const Collection& collection, 89ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch const typename Collection::value_type::first_type& key) { 90ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch typename Collection::const_iterator it = collection.find(key); 91ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch GOOGLE_CHECK(it != collection.end()) << "Map key not found: " << key; 92ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch return it->second; 93ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch} 94ba5b9a6411cb1792fd21f0a078d7a25cd1ceec16Ben Murdoch 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Perform a lookup in a map or hash_map whose values are pointers. 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// If the key is present a const pointer to the associated value is returned, 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// otherwise a NULL pointer is returned. 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// This function does not distinguish between a missing key and a key mapped 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// to a NULL value. 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)template <class Collection> 1015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)const typename Collection::value_type::second_type 1025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)FindPtrOrNull(const Collection& collection, 1035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const typename Collection::value_type::first_type& key) { 1045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) typename Collection::const_iterator it = collection.find(key); 1055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (it == collection.end()) { 1065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return 0; 1075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return it->second; 1095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Change the value associated with a particular key in a map or hash_map. 1125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// If the key is not present in the map the key and value are inserted, 1135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// otherwise the value is updated to be a copy of the value provided. 1145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// True indicates that an insert took place, false indicates an update. 1155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)template <class Collection, class Key, class Value> 1165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)bool InsertOrUpdate(Collection * const collection, 1175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const Key& key, const Value& value) { 1185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) pair<typename Collection::iterator, bool> ret = 1195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) collection->insert(typename Collection::value_type(key, value)); 1205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (!ret.second) { 1215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // update 1225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ret.first->second = value; 1235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return false; 1245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return true; 1265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Insert a new key and value into a map or hash_map. 1295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// If the key is not present in the map the key and value are 1305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// inserted, otherwise nothing happens. True indicates that an insert 1315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// took place, false indicates the key was already present. 1325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)template <class Collection, class Key, class Value> 1335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)bool InsertIfNotPresent(Collection * const collection, 1345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const Key& key, const Value& value) { 1355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) pair<typename Collection::iterator, bool> ret = 1365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) collection->insert(typename Collection::value_type(key, value)); 1375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return ret.second; 1385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace protobuf 1415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace google 1425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif // GOOGLE_PROTOBUF_STUBS_MAP_UTIL_H__ 144