added ValResponse class to parse JSON from http

libgrive/CMakeLists.txt

@@ -65,6 +65,7 @@ file (GLOB LIBGRIVE_SRC
 	src/drive2/*.cc
 	src/http/*.cc
 	src/protocol/*.cc
+	src/json/*.cc
 	src/util/*.cc
 	src/util/log/*.cc
 	src/xml/*.cc

libgrive/src/json/JsonParser.cc

@@ -0,0 +1,174 @@
+/*
+	grive: an GPL program to sync a local directory with Google Drive
+	Copyright (C) 2013 Wan Wai Ho
+
+	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 version 2
+	of the License.
+
+	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, write to the Free Software
+	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+	MA  02110-1301, USA.
+*/
+
+#include "JsonParser.hh"
+
+#include "Val.hh"
+#include "ValBuilder.hh"
+
+#include <yajl/yajl_parse.h>
+
+namespace gr {
+
+namespace
+{
+	int OnNull( void *ctx )
+	{
+		ValVisitor *b = reinterpret_cast<ValVisitor*>(ctx) ;
+		b->VisitNull() ;
+		return true ;
+	}
+
+	int OnBool( void *ctx, int value )
+	{
+		ValVisitor *b = reinterpret_cast<ValVisitor*>(ctx) ;
+		b->Visit( static_cast<long long>(value) ) ;
+		return true ;
+	}
+
+	int OnInt( void *ctx, long long value )
+	{
+		ValVisitor *b = reinterpret_cast<ValVisitor*>(ctx) ;
+		b->Visit(value) ;
+		return true ;
+	}
+
+	int OnDouble( void *ctx, double value )
+	{
+		ValVisitor *b = reinterpret_cast<ValVisitor*>(ctx) ;
+		b->Visit(value) ;
+		return true ;
+	}
+
+	int OnStr( void *ctx, const unsigned char *str, std::size_t len )
+	{
+		ValVisitor *b = reinterpret_cast<ValVisitor*>(ctx) ;
+		b->Visit( std::string(reinterpret_cast<const char*>(str), len) ) ;
+		return true ;
+	}
+
+	int StartMap( void *ctx )
+	{
+		ValVisitor *b = reinterpret_cast<ValVisitor*>(ctx) ;
+		b->StartObject() ;
+		return true ;
+	}
+
+	int OnMapKey( void *ctx, const unsigned char *str, std::size_t len )
+	{
+		ValVisitor *b = reinterpret_cast<ValVisitor*>(ctx) ;
+		b->VisitKey( std::string(reinterpret_cast<const char*>(str), len) ) ;
+		return true ;
+	}
+
+	int EndMap( void *ctx )
+	{
+		ValVisitor *b = reinterpret_cast<ValVisitor*>(ctx) ;
+		b->EndObject() ;
+		return true ;
+	}
+
+	int StartArray( void *ctx )
+	{
+		ValVisitor *b = reinterpret_cast<ValVisitor*>(ctx) ;
+		b->StartArray() ;
+		return true ;
+	}
+
+	int EndArray( void *ctx )
+	{
+		ValVisitor *b = reinterpret_cast<ValVisitor*>(ctx) ;
+		b->EndArray() ;
+		return true ;
+	}
+
+	const yajl_callbacks callbacks = {  
+		OnNull,  
+		OnBool,  
+		OnInt,  
+		OnDouble,  
+		0,  
+		OnStr,  
+		StartMap,  
+		OnMapKey,  
+		EndMap,  
+		StartArray,  
+		EndArray,  
+	};  
+}
+
+void JsonParser::Parse( const std::string& json, ValVisitor *callback )
+{
+	JsonParser parser( callback ) ;
+	parser.Parse( json.c_str(), json.size() ) ;
+	parser.Finish() ;
+}
+
+struct JsonParser::Impl
+{
+	ValVisitor	*callback ;
+	yajl_handle	hand ;
+} ;
+
+JsonParser::JsonParser( ValVisitor *callback ) :
+	m_impl( new Impl )
+{
+	m_impl->callback	= callback ;
+	m_impl->hand		= yajl_alloc( &callbacks, 0, m_impl->callback ) ;
+}
+
+JsonParser::~JsonParser()
+{
+	yajl_free( m_impl->hand ) ;
+}
+
+void JsonParser::Parse( const char *str, std::size_t size )
+{
+	const unsigned char *ustr = reinterpret_cast<unsigned const char*>(str) ;
+
+	yajl_status r = yajl_parse( m_impl->hand, ustr, size ) ;
+
+	if ( r != yajl_status_ok )
+	{
+		unsigned char *msg = yajl_get_error( m_impl->hand, true, ustr, size ) ;
+		std::string msg_str(reinterpret_cast<char*>(msg)) ;
+		yajl_free_error(m_impl->hand, msg) ;
+
+		BOOST_THROW_EXCEPTION(
+			Error()
+				<< ParseErr_(msg_str)
+				<< JsonText_(std::string(str,size))
+		);
+	}
+}
+
+void JsonParser::Finish()
+{
+	if ( yajl_complete_parse(m_impl->hand) != yajl_status_ok )
+	{
+		unsigned char *msg = yajl_get_error( m_impl->hand, false, 0, 0 ) ;
+		std::string msg_str(reinterpret_cast<char*>(msg)) ;
+		yajl_free_error(m_impl->hand, msg) ;
+
+		BOOST_THROW_EXCEPTION( Error() << ParseErr_(msg_str) ) ;
+	}
+}
+
+} // end of namespace gr::json

libgrive/src/json/JsonParser.hh

@@ -0,0 +1,53 @@
+/*
+	grive: an GPL program to sync a local directory with Google Drive
+	Copyright (C) 2013 Wan Wai Ho
+
+	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 version 2
+	of the License.
+
+	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, write to the Free Software
+	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+	MA  02110-1301, USA.
+*/
+
+#pragma once
+
+#include "util/Exception.hh"
+
+#include <string>
+#include <memory>
+
+namespace gr {
+
+class ValVisitor ;
+
+class JsonParser
+{
+public :
+	struct Error : virtual Exception {} ;
+	typedef boost::error_info<struct ParseErr,	std::string> ParseErr_ ;
+	typedef boost::error_info<struct JsonText,	std::string> JsonText_ ;
+
+	static void Parse( const std::string& json, ValVisitor *callback ) ;
+
+	explicit JsonParser( ValVisitor *callback ) ;
+	~JsonParser() ;
+
+	void Parse( const char *str, std::size_t size ) ;
+	void Finish() ;
+
+private :
+	struct Impl ;
+	std::auto_ptr<Impl>	m_impl ;
+} ;
+
+} // end of namespace
+