1// Protocol Buffers - Google's data interchange format 2// Copyright 2008 Google Inc. All rights reserved. 3// http://code.google.com/p/protobuf/ 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 38namespace google { 39namespace 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. 51template <class ForwardIterator> 52void 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. 67inline 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. 83inline 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. 98template <class T> 99void 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 109template <class T> 110void 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