memorystream.h
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//
// Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved.
//
// Licensed under the MIT License (the "License"); you may not use this file except
// in compliance with the License. You may obtain a copy of the License at
//
// http://opensource.org/licenses/MIT
//
// 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
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#ifndef RAPIDJSON_MEMORYSTREAM_H_
#define RAPIDJSON_MEMORYSTREAM_H_
#include "stream.h"
#ifdef __clang__
RAPIDJSON_DIAG_PUSH
RAPIDJSON_DIAG_OFF(unreachable-code)
RAPIDJSON_DIAG_OFF(missing-noreturn)
#endif
RAPIDJSON_NAMESPACE_BEGIN
//! Represents an in-memory input byte stream.
/*!
This class is mainly for being wrapped by EncodedInputStream or AutoUTFInputStream.
It is similar to FileReadBuffer but the source is an in-memory buffer instead of a file.
Differences between MemoryStream and StringStream:
1. StringStream has encoding but MemoryStream is a byte stream.
2. MemoryStream needs size of the source buffer and the buffer don't need to be null terminated. StringStream assume null-terminated string as source.
3. MemoryStream supports Peek4() for encoding detection. StringStream is specified with an encoding so it should not have Peek4().
\note implements Stream concept
*/
struct MemoryStream {
typedef char Ch; // byte
MemoryStream(const Ch *src, size_t size) : src_(src), begin_(src), end_(src + size), size_(size) {}
Ch Peek() const { return RAPIDJSON_UNLIKELY(src_ == end_) ? '\0' : *src_; }
Ch Take() { return RAPIDJSON_UNLIKELY(src_ == end_) ? '\0' : *src_++; }
size_t Tell() const { return static_cast<size_t>(src_ - begin_); }
Ch* PutBegin() { RAPIDJSON_ASSERT(false); return 0; }
void Put(Ch) { RAPIDJSON_ASSERT(false); }
void Flush() { RAPIDJSON_ASSERT(false); }
size_t PutEnd(Ch*) { RAPIDJSON_ASSERT(false); return 0; }
// For encoding detection only.
const Ch* Peek4() const {
return Tell() + 4 <= size_ ? src_ : 0;
}
const Ch* src_; //!< Current read position.
const Ch* begin_; //!< Original head of the string.
const Ch* end_; //!< End of stream.
size_t size_; //!< Size of the stream.
};
RAPIDJSON_NAMESPACE_END
#ifdef __clang__
RAPIDJSON_DIAG_POP
#endif
#endif // RAPIDJSON_MEMORYBUFFER_H_
rapidjson::MemoryStream
Represents an in-memory input byte stream.
Definition: memorystream.h:40
rapidjson::MemoryStream::size_
size_t size_
Size of the stream.
Definition: memorystream.h:62
rapidjson::MemoryStream::end_
const Ch * end_
End of stream.
Definition: memorystream.h:61
rapidjson::MemoryStream::begin_
const Ch * begin_
Original head of the string.
Definition: memorystream.h:60
RAPIDJSON_UNLIKELY
#define RAPIDJSON_UNLIKELY(x)
Compiler branching hint for expression with low probability to be true.
Definition: rapidjson.h:468
rapidjson::MemoryStream::src_
const Ch * src_
Current read position.
Definition: memorystream.h:59
RAPIDJSON_ASSERT
#define RAPIDJSON_ASSERT(x)
Assertion.
Definition: rapidjson.h:402