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