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+// Tencent is pleased to support the open source community by making RapidJSON available.
+//
+// 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
+// CONDITIONS OF ANY KIND, either express or implied. See the License for the
+// specific language governing permissions and limitations under the License.
+
+#include "rapidjson.h"
+
+#ifndef RAPIDJSON_STREAM_H_
+#define RAPIDJSON_STREAM_H_
+
+#include "encodings.h"
+
+RAPIDJSON_NAMESPACE_BEGIN
+
+///////////////////////////////////////////////////////////////////////////////
+// Stream
+
+/*! \class rapidjson::Stream
+ \brief Concept for reading and writing characters.
+
+ For read-only stream, no need to implement PutBegin(), Put(), Flush() and PutEnd().
+
+ For write-only stream, only need to implement Put() and Flush().
+
+\code
+concept Stream {
+ typename Ch; //!< Character type of the stream.
+
+ //! Read the current character from stream without moving the read cursor.
+ Ch Peek() const;
+
+ //! Read the current character from stream and moving the read cursor to next character.
+ Ch Take();
+
+ //! Get the current read cursor.
+ //! \return Number of characters read from start.
+ size_t Tell();
+
+ //! Begin writing operation at the current read pointer.
+ //! \return The begin writer pointer.
+ Ch* PutBegin();
+
+ //! Write a character.
+ void Put(Ch c);
+
+ //! Flush the buffer.
+ void Flush();
+
+ //! End the writing operation.
+ //! \param begin The begin write pointer returned by PutBegin().
+ //! \return Number of characters written.
+ size_t PutEnd(Ch* begin);
+}
+\endcode
+*/
+
+//! Provides additional information for stream.
+/*!
+ By using traits pattern, this type provides a default configuration for stream.
+ For custom stream, this type can be specialized for other configuration.
+ See TEST(Reader, CustomStringStream) in readertest.cpp for example.
+*/
+template<typename Stream>
+struct StreamTraits {
+ //! Whether to make local copy of stream for optimization during parsing.
+ /*!
+ By default, for safety, streams do not use local copy optimization.
+ Stream that can be copied fast should specialize this, like StreamTraits<StringStream>.
+ */
+ enum { copyOptimization = 0 };
+};
+
+//! Reserve n characters for writing to a stream.
+template<typename Stream>
+inline void PutReserve(Stream& stream, size_t count) {
+ (void)stream;
+ (void)count;
+}
+
+//! Write character to a stream, presuming buffer is reserved.
+template<typename Stream>
+inline void PutUnsafe(Stream& stream, typename Stream::Ch c) {
+ stream.Put(c);
+}
+
+//! Put N copies of a character to a stream.
+template<typename Stream, typename Ch>
+inline void PutN(Stream& stream, Ch c, size_t n) {
+ PutReserve(stream, n);
+ for (size_t i = 0; i < n; i++)
+ PutUnsafe(stream, c);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// GenericStreamWrapper
+
+//! A Stream Wrapper
+/*! \tThis string stream is a wrapper for any stream by just forwarding any
+ \treceived message to the origin stream.
+ \note implements Stream concept
+*/
+
+#if defined(_MSC_VER) && _MSC_VER <= 1800
+RAPIDJSON_DIAG_PUSH
+RAPIDJSON_DIAG_OFF(4702) // unreachable code
+RAPIDJSON_DIAG_OFF(4512) // assignment operator could not be generated
+#endif
+
+template <typename InputStream, typename Encoding = UTF8<> >
+class GenericStreamWrapper {
+public:
+ typedef typename Encoding::Ch Ch;
+ GenericStreamWrapper(InputStream& is): is_(is) {}
+
+ Ch Peek() const { return is_.Peek(); }
+ Ch Take() { return is_.Take(); }
+ size_t Tell() { return is_.Tell(); }
+ Ch* PutBegin() { return is_.PutBegin(); }
+ void Put(Ch ch) { is_.Put(ch); }
+ void Flush() { is_.Flush(); }
+ size_t PutEnd(Ch* ch) { return is_.PutEnd(ch); }
+
+ // wrapper for MemoryStream
+ const Ch* Peek4() const { return is_.Peek4(); }
+
+ // wrapper for AutoUTFInputStream
+ UTFType GetType() const { return is_.GetType(); }
+ bool HasBOM() const { return is_.HasBOM(); }
+
+protected:
+ InputStream& is_;
+};
+
+#if defined(_MSC_VER) && _MSC_VER <= 1800
+RAPIDJSON_DIAG_POP
+#endif
+
+///////////////////////////////////////////////////////////////////////////////
+// StringStream
+
+//! Read-only string stream.
+/*! \note implements Stream concept
+*/
+template <typename Encoding>
+struct GenericStringStream {
+ typedef typename Encoding::Ch Ch;
+
+ GenericStringStream(const Ch *src) : src_(src), head_(src) {}
+
+ Ch Peek() const { return *src_; }
+ Ch Take() { return *src_++; }
+ size_t Tell() const { return static_cast<size_t>(src_ - head_); }
+
+ 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; }
+
+ const Ch* src_; //!< Current read position.
+ const Ch* head_; //!< Original head of the string.
+};
+
+template <typename Encoding>
+struct StreamTraits<GenericStringStream<Encoding> > {
+ enum { copyOptimization = 1 };
+};
+
+//! String stream with UTF8 encoding.
+typedef GenericStringStream<UTF8<> > StringStream;
+
+///////////////////////////////////////////////////////////////////////////////
+// InsituStringStream
+
+//! A read-write string stream.
+/*! This string stream is particularly designed for in-situ parsing.
+ \note implements Stream concept
+*/
+template <typename Encoding>
+struct GenericInsituStringStream {
+ typedef typename Encoding::Ch Ch;
+
+ GenericInsituStringStream(Ch *src) : src_(src), dst_(0), head_(src) {}
+
+ // Read
+ Ch Peek() { return *src_; }
+ Ch Take() { return *src_++; }
+ size_t Tell() { return static_cast<size_t>(src_ - head_); }
+
+ // Write
+ void Put(Ch c) { RAPIDJSON_ASSERT(dst_ != 0); *dst_++ = c; }
+
+ Ch* PutBegin() { return dst_ = src_; }
+ size_t PutEnd(Ch* begin) { return static_cast<size_t>(dst_ - begin); }
+ void Flush() {}
+
+ Ch* Push(size_t count) { Ch* begin = dst_; dst_ += count; return begin; }
+ void Pop(size_t count) { dst_ -= count; }
+
+ Ch* src_;
+ Ch* dst_;
+ Ch* head_;
+};
+
+template <typename Encoding>
+struct StreamTraits<GenericInsituStringStream<Encoding> > {
+ enum { copyOptimization = 1 };
+};
+
+//! Insitu string stream with UTF8 encoding.
+typedef GenericInsituStringStream<UTF8<> > InsituStringStream;
+
+RAPIDJSON_NAMESPACE_END
+
+#endif // RAPIDJSON_STREAM_H_