vn-verdnaturachat/ios/Pods/Flipper-Folly/folly/io/Cursor-inl.h

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/*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
namespace folly {
namespace io {
namespace detail {
/*
* Helper classes for use with CursorBase::readWhile()
*/
class CursorStringAppender {
public:
void append(ByteRange bytes) {
str_.append(reinterpret_cast<char const*>(bytes.data()), bytes.size());
}
std::string extractString() {
return std::move(str_);
}
private:
std::string str_;
};
class CursorNoopAppender {
public:
void append(ByteRange) {}
};
template <class Derived, class BufType>
std::string CursorBase<Derived, BufType>::readTerminatedString(
char termChar,
size_t maxLength) {
size_t bytesRead{0};
auto keepReading = [&bytesRead, termChar, maxLength](uint8_t byte) {
if (byte == termChar) {
return false;
}
++bytesRead;
if (bytesRead >= maxLength) {
throw std::length_error("string overflow");
}
return true;
};
auto result = readWhile(keepReading);
// skip over the terminator character
if (isAtEnd()) {
throw_exception<std::out_of_range>("terminator not found");
}
skip(1);
return result;
}
template <class Derived, class BufType>
template <typename Predicate>
std::string CursorBase<Derived, BufType>::readWhile(
const Predicate& predicate) {
CursorStringAppender s;
readWhile(predicate, s);
return s.extractString();
}
template <class Derived, class BufType>
template <typename Predicate, typename Output>
void CursorBase<Derived, BufType>::readWhile(
const Predicate& predicate,
Output& out) {
while (true) {
auto peeked = peekBytes();
if (peeked.empty()) {
return;
}
for (size_t idx = 0; idx < peeked.size(); ++idx) {
if (!predicate(peeked[idx])) {
peeked.reset(peeked.data(), idx);
out.append(peeked);
skip(idx);
return;
}
}
out.append(peeked);
skip(peeked.size());
}
}
template <class Derived, class BufType>
template <typename Predicate>
void CursorBase<Derived, BufType>::skipWhile(const Predicate& predicate) {
CursorNoopAppender appender;
readWhile(predicate, appender);
}
} // namespace detail
} // namespace io
} // namespace folly