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- // Licensed to the Apache Software Foundation (ASF) under one
- // or more contributor license agreements. See the NOTICE file
- // distributed with this work for additional information
- // regarding copyright ownership. The ASF licenses this file
- // to you 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.
- // Date: Tue Jun 23 15:03:24 CST 2015
- #ifndef BUTIL_FIND_CSTR_H
- #define BUTIL_FIND_CSTR_H
- #include <string>
- #include <map>
- #include <algorithm>
- #include "butil/thread_local.h"
- // Find c-string in maps with std::string as keys without memory allocations.
- // Example:
- // std::map<std::string, int> string_map;
- //
- // string_map.find("hello"); // constructed a temporary std::string
- // // which needs memory allocation.
- //
- // find_cstr(string_map, "hello"); // no allocation.
- //
- // You can specialize find_cstr for other maps.
- // Possible prototypes are:
- // const_iterator find_cstr(const Map& map, const char* key);
- // iterator find_cstr(Map& map, const char* key);
- // const_iterator find_cstr(const Map& map, const char* key, size_t length);
- // iterator find_cstr(Map& map, const char* key, size_t length);
- namespace butil {
- struct StringMapThreadLocalTemp {
- bool initialized;
- char buf[sizeof(std::string)];
- static void delete_tls(void* buf) {
- StringMapThreadLocalTemp* temp = (StringMapThreadLocalTemp*)buf;
- if (temp->initialized) {
- temp->initialized = false;
- std::string* temp_string = (std::string*)temp->buf;
- temp_string->~basic_string();
- }
- }
- inline std::string* get_string(const char* key) {
- if (!initialized) {
- initialized = true;
- std::string* tmp = new (buf) std::string(key);
- thread_atexit(delete_tls, this);
- return tmp;
- } else {
- std::string* tmp = (std::string*)buf;
- tmp->assign(key);
- return tmp;
- }
- }
- inline std::string* get_string(const char* key, size_t length) {
- if (!initialized) {
- initialized = true;
- std::string* tmp = new (buf) std::string(key, length);
- thread_atexit(delete_tls, this);
- return tmp;
- } else {
- std::string* tmp = (std::string*)buf;
- tmp->assign(key, length);
- return tmp;
- }
- }
- inline std::string* get_lowered_string(const char* key) {
- std::string* tmp = get_string(key);
- std::transform(tmp->begin(), tmp->end(), tmp->begin(), ::tolower);
- return tmp;
- }
-
- inline std::string* get_lowered_string(const char* key, size_t length) {
- std::string* tmp = get_string(key, length);
- std::transform(tmp->begin(), tmp->end(), tmp->begin(), ::tolower);
- return tmp;
- }
- };
- extern thread_local StringMapThreadLocalTemp tls_stringmap_temp;
- template <typename T, typename C, typename A>
- typename std::map<std::string, T, C, A>::const_iterator
- find_cstr(const std::map<std::string, T, C, A>& m, const char* key) {
- return m.find(*tls_stringmap_temp.get_string(key));
- }
- template <typename T, typename C, typename A>
- typename std::map<std::string, T, C, A>::iterator
- find_cstr(std::map<std::string, T, C, A>& m, const char* key) {
- return m.find(*tls_stringmap_temp.get_string(key));
- }
- template <typename T, typename C, typename A>
- typename std::map<std::string, T, C, A>::const_iterator
- find_cstr(const std::map<std::string, T, C, A>& m,
- const char* key, size_t length) {
- return m.find(*tls_stringmap_temp.get_string(key, length));
- }
- template <typename T, typename C, typename A>
- typename std::map<std::string, T, C, A>::iterator
- find_cstr(std::map<std::string, T, C, A>& m,
- const char* key, size_t length) {
- return m.find(*tls_stringmap_temp.get_string(key, length));
- }
- template <typename T, typename C, typename A>
- typename std::map<std::string, T, C, A>::const_iterator
- find_lowered_cstr(const std::map<std::string, T, C, A>& m, const char* key) {
- return m.find(*tls_stringmap_temp.get_lowered_string(key));
- }
- template <typename T, typename C, typename A>
- typename std::map<std::string, T, C, A>::iterator
- find_lowered_cstr(std::map<std::string, T, C, A>& m, const char* key) {
- return m.find(*tls_stringmap_temp.get_lowered_string(key));
- }
- template <typename T, typename C, typename A>
- typename std::map<std::string, T, C, A>::const_iterator
- find_lowered_cstr(const std::map<std::string, T, C, A>& m,
- const char* key, size_t length) {
- return m.find(*tls_stringmap_temp.get_lowered_string(key, length));
- }
- template <typename T, typename C, typename A>
- typename std::map<std::string, T, C, A>::iterator
- find_lowered_cstr(std::map<std::string, T, C, A>& m,
- const char* key, size_t length) {
- return m.find(*tls_stringmap_temp.get_lowered_string(key, length));
- }
- } // namespace butil
- #endif // BUTIL_FIND_CSTR_H
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