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>
STLDeleteContainerPointers(ForwardIterator begin,ForwardIterator end)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.
STLStringResizeUninitialized(string * s,size_t new_size)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.
string_as_array(string * str)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>
STLDeleteElements(T * container)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>
STLDeleteValues(T * v)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