86 lines
3.7 KiB
C++
86 lines
3.7 KiB
C++
// Protocol Buffers - Google's data interchange format
|
|
// Copyright 2008 Google Inc. All rights reserved.
|
|
// https://developers.google.com/protocol-buffers/
|
|
//
|
|
// Redistribution and use in source and binary forms, with or without
|
|
// modification, are permitted provided that the following conditions are
|
|
// met:
|
|
//
|
|
// * Redistributions of source code must retain the above copyright
|
|
// notice, this list of conditions and the following disclaimer.
|
|
// * Redistributions in binary form must reproduce the above
|
|
// copyright notice, this list of conditions and the following disclaimer
|
|
// in the documentation and/or other materials provided with the
|
|
// distribution.
|
|
// * Neither the name of Google Inc. nor the names of its
|
|
// contributors may be used to endorse or promote products derived from
|
|
// this software without specific prior written permission.
|
|
//
|
|
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
// from google3/util/gtl/stl_util.h
|
|
|
|
#ifndef GOOGLE_PROTOBUF_STUBS_STL_UTIL_H__
|
|
#define GOOGLE_PROTOBUF_STUBS_STL_UTIL_H__
|
|
|
|
#include <google/protobuf/stubs/common.h>
|
|
|
|
#include <algorithm>
|
|
|
|
namespace google {
|
|
namespace protobuf {
|
|
|
|
// Inside Google, this function implements a horrible, disgusting hack in which
|
|
// we reach into the string's private implementation and resize it without
|
|
// initializing the new bytes. In some cases doing this can significantly
|
|
// improve performance. However, since it's totally non-portable it has no
|
|
// place in open source code. Feel free to fill this function in with your
|
|
// own disgusting hack if you want the perf boost.
|
|
inline void STLStringResizeUninitialized(std::string* s, size_t new_size) {
|
|
s->resize(new_size);
|
|
}
|
|
|
|
// As above, but we make sure to follow amortized growth in which we always
|
|
// increase the capacity by at least a constant factor >1.
|
|
inline void STLStringResizeUninitializedAmortized(std::string* s,
|
|
size_t new_size) {
|
|
const size_t cap = s->capacity();
|
|
if (new_size > cap) {
|
|
// Make sure to always grow by at least a factor of 2x.
|
|
s->reserve(std::max(new_size, 2 * cap));
|
|
}
|
|
STLStringResizeUninitialized(s, new_size);
|
|
}
|
|
|
|
// Return a mutable char* pointing to a string's internal buffer,
|
|
// which may not be null-terminated. Writing through this pointer will
|
|
// modify the string.
|
|
//
|
|
// string_as_array(&str)[i] is valid for 0 <= i < str.size() until the
|
|
// next call to a string method that invalidates iterators.
|
|
//
|
|
// As of 2006-04, there is no standard-blessed way of getting a
|
|
// mutable reference to a string's internal buffer. However, issue 530
|
|
// (http://www.open-std.org/JTC1/SC22/WG21/docs/lwg-active.html#530)
|
|
// proposes this as the method. According to Matt Austern, this should
|
|
// already work on all current implementations.
|
|
inline char* string_as_array(std::string* str) {
|
|
// DO NOT USE const_cast<char*>(str->data())! See the unittest for why.
|
|
return str->empty() ? nullptr : &*str->begin();
|
|
}
|
|
|
|
} // namespace protobuf
|
|
} // namespace google
|
|
|
|
#endif // GOOGLE_PROTOBUF_STUBS_STL_UTIL_H__
|