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/* Copyright 2015 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects
* for all of the code used other than as permitted herein. If you modify
* file(s) with this exception, you may extend this exception to your
* version of the file(s), but you are not obligated to do so. If you do not
* wish to do so, delete this exception statement from your version. If you
* delete this exception statement from all source files in the program,
* then also delete it in the license file.
*/
#pragma once
#include <cstddef>
#include <cstring>
#include <limits>
#include "mongo/base/data_range.h"
#include "mongo/base/data_type.h"
#include "mongo/platform/endian.h"
#include "mongo/util/mongoutils/str.h"
namespace mongo {
class ConstDataRangeCursor : public ConstDataRange {
public:
ConstDataRangeCursor(const char* begin, const char* end, std::ptrdiff_t debug_offset = 0)
: ConstDataRange(begin, end, debug_offset) {}
ConstDataRangeCursor(ConstDataRange cdr) : ConstDataRange(cdr) {}
Status advance(size_t advance) {
if (advance > length()) {
return makeAdvanceStatus(advance);
}
_begin += advance;
_debug_offset += advance;
return Status::OK();
}
template <typename T>
Status skip() {
size_t advanced = 0;
Status x = DataType::load<T>(nullptr, _begin, _end - _begin, &advanced, _debug_offset);
if (x.isOK()) {
_begin += advanced;
_debug_offset += advanced;
}
return x;
}
template <typename T>
Status readAndAdvance(T* t) {
size_t advanced = 0;
Status x = DataType::load(t, _begin, _end - _begin, &advanced, _debug_offset);
if (x.isOK()) {
_begin += advanced;
_debug_offset += advanced;
}
return x;
}
template <typename T>
StatusWith<T> readAndAdvance() {
T out(DataType::defaultConstruct<T>());
Status x = readAndAdvance(&out);
if (x.isOK()) {
return StatusWith<T>(std::move(out));
} else {
return StatusWith<T>(std::move(x));
}
}
private:
Status makeAdvanceStatus(size_t advance) const;
};
class DataRangeCursor : public DataRange {
public:
DataRangeCursor(char* begin, char* end, std::ptrdiff_t debug_offset = 0)
: DataRange(begin, end, debug_offset) {}
DataRangeCursor(DataRange range) : DataRange(range) {}
operator ConstDataRangeCursor() const {
return ConstDataRangeCursor(ConstDataRange(_begin, _end, _debug_offset));
}
Status advance(size_t advance) {
if (advance > length()) {
return makeAdvanceStatus(advance);
}
_begin += advance;
_debug_offset += advance;
return Status::OK();
}
template <typename T>
Status skip() {
size_t advanced = 0;
Status x = DataType::load<T>(nullptr, _begin, _end - _begin, &advanced, _debug_offset);
if (x.isOK()) {
_begin += advanced;
_debug_offset += advanced;
}
return x;
}
template <typename T>
Status readAndAdvance(T* t) {
size_t advanced = 0;
Status x = DataType::load(t, _begin, _end - _begin, &advanced, _debug_offset);
if (x.isOK()) {
_begin += advanced;
_debug_offset += advanced;
}
return x;
}
template <typename T>
StatusWith<T> readAndAdvance() {
T out(DataType::defaultConstruct<T>());
Status x = readAndAdvance(&out);
if (x.isOK()) {
return StatusWith<T>(std::move(out));
} else {
return StatusWith<T>(std::move(x));
}
}
template <typename T>
Status writeAndAdvance(const T& value) {
size_t advanced = 0;
Status x = DataType::store(
value, const_cast<char*>(_begin), _end - _begin, &advanced, _debug_offset);
if (x.isOK()) {
_begin += advanced;
_debug_offset += advanced;
}
return x;
}
private:
Status makeAdvanceStatus(size_t advance) const;
};
} // namespace mongo
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