PIChunkStream

git-svn-id: svn://db.shs.com.ru/pip@176 12ceb7fc-bf1f-11e4-8940-5bc7170c53b5

src/core/pichunkstream.cpp

@@ -0,0 +1,55 @@
+#include "pichunkstream.h"
+
+/*! \class PIChunkStream
+ * \brief Class for binary serialization
+ * 
+ * \section PIChunkStream_sec0 Synopsis
+ * This class provides very handly mechanism to store and restore values to and from
+ * \a PIByteArray. The main advantage of using this class is that your binary data
+ * become independent from order and collection of your values.
+ * 
+ * \section PIChunkStream_sec1 Mechanism
+ * %PIChunkStream works with items called "chunk". Chunk is an ID and any value that
+ * can be stored and restored to \a PIByteArray with stream operators << and >>.
+ * You can place chunks to stream and read chunks from stream.
+ * 
+ * To construct %PIChunkStream for writing data use any constructor. Empty constructor
+ * creates internal empty buffer that can be accessed by function \a data().
+ * Non-empty constructor works with given byte array.
+ * 
+ * To read chunks from byte array use function \a read() that returns ID of
+ * next chunk. Then you can get value of this chunk with function \a getData(),
+ * but you should definitely know type of this value. You can read from byte array
+ * while \a atEnd() if false.
+ * 
+ * \section PIChunkStream_ex0 Example
+ * Prepare your structs to work with %PIChunkStream
+ * \snippet pichunkstream.cpp struct
+ * Writing to %PIChunkStream
+ * \snippet pichunkstream.cpp write
+ * Reading from %PIChunkStream
+ * \snippet pichunkstream.cpp read
+ */
+
+
+void PIChunkStream::setSource(const PIByteArray & data) {
+	data_ = const_cast<PIByteArray*>(&data);
+	_init();
+}
+
+
+void PIChunkStream::setSource(PIByteArray * data) {
+	data_ = (data ? data : &tmp_data);
+	_init();
+}
+
+
+PIChunkStream::~PIChunkStream() {
+
+}
+
+
+void PIChunkStream::_init() {
+	last_id = -1;
+	last_data.clear();
+}

src/core/pichunkstream.h

@@ -0,0 +1,88 @@
+/*! \file pichunkstream.h
+ * \brief Binary serializator
+*/
+/*
+    PIP - Platform Independent Primitives
+    Binary serializator
+    Copyright (C) 2015  Ivan Pelipenko peri4ko@gmail.com
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef PICHUNKSTREAM_H
+#define PICHUNKSTREAM_H
+
+#include "pibytearray.h"
+
+
+class PIChunkStream
+{
+public:
+	
+	//! Contructs stream for read from "data"
+	PIChunkStream(const PIByteArray & data) {setSource(data);}
+	
+	//! Contructs stream for read or write to/from "data", or empty stream for write
+	PIChunkStream(PIByteArray * data = 0) {setSource(data);}
+	
+	~PIChunkStream();
+	
+	template <typename T>
+	struct Chunk {
+		Chunk(int i, const T & d): id(i), data(d) {}
+		int id;
+		T data;
+	};
+	
+	//! Returns chunk with ID "id" and value "data" for write to stream
+	template <typename T> static Chunk<T> chunk(int id, const T & data) {return Chunk<T>(id, data);}
+	
+	void setSource(const PIByteArray & data);
+	void setSource(PIByteArray * data);
+	
+	//! Returns internal buffer with written data
+	PIByteArray data() const {return tmp_data;}
+	
+	//! Returns if there is end of stream
+	bool atEnd() const {return data_->isEmpty();}
+	
+	
+	//! Read one chunk from stream and returns its ID
+	int read() {(*data_) >> last_id >> last_data; return last_id;}
+	
+	//! Returns last readed chunk ID
+	int getID() {return last_id;}
+	
+	//! Returns value of last readed chunk
+	template <typename T>
+	T getData() const {T ret; PIByteArray s(last_data); s >> ret; return ret;}
+	
+private:
+	void _init();
+	
+	int last_id;
+	PIByteArray * data_, last_data, tmp_data;
+	
+	template <typename T> friend PIChunkStream & operator <<(PIChunkStream & s, const PIChunkStream::Chunk<T> & c);
+};
+
+template <typename T>
+PIChunkStream & operator <<(PIChunkStream & s, const PIChunkStream::Chunk<T> & c) {
+	PIByteArray ba;
+	ba << c.data;
+	(*(s.data_)) << c.id << ba;
+	return s;
+}
+
+#endif // PICHUNKSTREAM_H

src/core/picoremodule.h

@@ -27,5 +27,6 @@
 #include "pitime.h"
 #include "pivariant.h"
 #include "picli.h"
+#include "pichunkstream.h"
 
 #endif // PICOREMODULE_H