1 // Protocol Buffers - Google's data interchange format 2 // Copyright 2008 Google Inc. All rights reserved. 3 // https://developers.google.com/protocol-buffers/ 4 // 5 // Redistribution and use in source and binary forms, with or without 6 // modification, are permitted provided that the following conditions are 7 // met: 8 // 9 // * Redistributions of source code must retain the above copyright 10 // notice, this list of conditions and the following disclaimer. 11 // * Redistributions in binary form must reproduce the above 12 // copyright notice, this list of conditions and the following disclaimer 13 // in the documentation and/or other materials provided with the 14 // distribution. 15 // * Neither the name of Google Inc. nor the names of its 16 // contributors may be used to endorse or promote products derived from 17 // this software without specific prior written permission. 18 // 19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 31 // from google3/util/gtl/stl_util.h 32 33 #ifndef GOOGLE_PROTOBUF_STUBS_STL_UTIL_H__ 34 #define GOOGLE_PROTOBUF_STUBS_STL_UTIL_H__ 35 36 #include <google/protobuf/stubs/common.h> 37 38 namespace google { 39 namespace protobuf { 40 41 // STLDeleteContainerPointers() 42 // For a range within a container of pointers, calls delete 43 // (non-array version) on these pointers. 44 // NOTE: for these three functions, we could just implement a DeleteObject 45 // functor and then call for_each() on the range and functor, but this 46 // requires us to pull in all of algorithm.h, which seems expensive. 47 // For hash_[multi]set, it is important that this deletes behind the iterator 48 // because the hash_set may call the hash function on the iterator when it is 49 // advanced, which could result in the hash function trying to deference a 50 // stale pointer. 51 template <class ForwardIterator> 52 void STLDeleteContainerPointers(ForwardIterator begin, 53 ForwardIterator end) { 54 while (begin != end) { 55 ForwardIterator temp = begin; 56 ++begin; 57 delete *temp; 58 } 59 } 60 61 // Inside Google, this function implements a horrible, disgusting hack in which 62 // we reach into the string's private implementation and resize it without 63 // initializing the new bytes. In some cases doing this can significantly 64 // improve performance. However, since it's totally non-portable it has no 65 // place in open source code. Feel free to fill this function in with your 66 // own disgusting hack if you want the perf boost. 67 inline void STLStringResizeUninitialized(string* s, size_t new_size) { 68 s->resize(new_size); 69 } 70 71 // Return a mutable char* pointing to a string's internal buffer, 72 // which may not be null-terminated. Writing through this pointer will 73 // modify the string. 74 // 75 // string_as_array(&str)[i] is valid for 0 <= i < str.size() until the 76 // next call to a string method that invalidates iterators. 77 // 78 // As of 2006-04, there is no standard-blessed way of getting a 79 // mutable reference to a string's internal buffer. However, issue 530 80 // (http://www.open-std.org/JTC1/SC22/WG21/docs/lwg-active.html#530) 81 // proposes this as the method. According to Matt Austern, this should 82 // already work on all current implementations. 83 inline char* string_as_array(string* str) { 84 // DO NOT USE const_cast<char*>(str->data())! See the unittest for why. 85 return str->empty() ? NULL : &*str->begin(); 86 } 87 88 // STLDeleteElements() deletes all the elements in an STL container and clears 89 // the container. This function is suitable for use with a vector, set, 90 // hash_set, or any other STL container which defines sensible begin(), end(), 91 // and clear() methods. 92 // 93 // If container is NULL, this function is a no-op. 94 // 95 // As an alternative to calling STLDeleteElements() directly, consider 96 // ElementDeleter (defined below), which ensures that your container's elements 97 // are deleted when the ElementDeleter goes out of scope. 98 template <class T> 99 void STLDeleteElements(T *container) { 100 if (!container) return; 101 STLDeleteContainerPointers(container->begin(), container->end()); 102 container->clear(); 103 } 104 105 // Given an STL container consisting of (key, value) pairs, STLDeleteValues 106 // deletes all the "value" components and clears the container. Does nothing 107 // in the case it's given a NULL pointer. 108 109 template <class T> 110 void STLDeleteValues(T *v) { 111 if (!v) return; 112 for (typename T::iterator i = v->begin(); i != v->end(); ++i) { 113 delete i->second; 114 } 115 v->clear(); 116 } 117 118 } // namespace protobuf 119 } // namespace google 120 121 #endif // GOOGLE_PROTOBUF_STUBS_STL_UTIL_H__ 122
