maperror.cpp

mini http server,可以集成嵌入到程序中,实现简单的web功能

/*____________________________________________________________________________*\
 *

 Copyright (c) 1997-2003 John Roy, Holger Zimmermann. All rights reserved.

 These sources, libraries and applications are
 FREE FOR COMMERCIAL AND NON-COMMERCIAL USE
 as long as the following conditions are adhered to.

 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions
 are met:

 1. Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer. 

 2. Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in
    the documentation and/or other materials provided with the
    distribution.

 3. The name of the author may not be used to endorse or promote products
    derived from this software without specific prior written permission.

 THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 IN NO EVENT SHALL THE AUTHORS OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 OF THE POSSIBILITY OF SUCH DAMAGE.

 *____________________________________________________________________________*|
 *
 * $Source: /cvsroot/pi3web/Pi3Web_200/Source/HTTP/MapError.cpp,v $
 * $Date: 2003/05/13 18:42:03 $
 *
 Description:
	Set an appropriate error document in the path when an error status
	code exists. Other actions may conditionally be taken.

\*____________________________________________________________________________*/
//$SourceTop:$

#include <ctype.h>

#include "HandBase.h"
#include "HTTPCore.h"
#include "HTTPUtil.h"
#include "PIStrStr.h"
#include "DblList.h"
#include "StrToken.h"

/*____________________________________________________________________________*\
 *
 Class:
 Description:
	Mapping from an error status code to the virtual path for that error.
\*____________________________________________________________________________*/
class ErrorMap
{
public:
	int iStatus;
	PIString sVirtualPath;

	ErrorMap( int iTheStatus, const char *pVirtualPath )
	: iStatus( iTheStatus ), sVirtualPath( pVirtualPath )
		{};
};

/*____________________________________________________________________________*\
 *
 Description:
\*____________________________________________________________________________*/
#define KEY_CONF_IGNORESTATUS		"IgnoreStatus"
#define KEY_CONF_DEFAULTMESSAGE		"DefaultMessage"
#define KEY_CONF_ACTION				"Action"

#if 0
	/*
	** HTML documentation for this handler
	*/
/*___+++HTMLDOC_BEGIN+++___*/
Name:
	MapToErrorDocument

Description:
	This handler sets an error document virtual path according to the
	HTTP error status code.
	Subsequent mapping handlers map this virtual path to a physical path.
	If a virtual path is mapped a number of the original client RFC822
	request headers are modified or removed, most notably, the Method
	is set to 'GET' and any 'If-Modified-Since' headers are removed. This
	avoids confusion where subsequent handlers interpret the error resource
	in the context of meta information of the original resource.

Options:
<H5>Overview</H5>
<TABLE BORDER=1>
<TH>Option
<TH>Default
<TH>Values
<TH>Short Description
<TH>Example(s)

<TR>
<TD>IgnoreStatus
<TD>-
<TD>0, 200, etc.
<TD>HTTP response codes
<TD>IgnoreStatus="0 200"

<TR>
<TD>&lt;nnn&gt;
<TD>-
<TD>/errors/404.html, /msgs/403.shtml, etc.
<TD>Response specific virtual error paths
<TD>404="/errors/404.html"; 403="/errors/403.shtml"

<TR>
<TD>DefaultMessage
<TD>+
<TD>/errors/Unknown.html, /msgs/unknown.shtml, etc.
<TD>Default error message virtual path
<TD>DefaultMessage="/errors/Unknown.html"

<TR>
<TD>Action
<TD>-
<TD>A Pi3Expression
<TD>Evaluated if the error code is mapped
<TD>Action="&dbreplace(response,sting,ObjectMap,...)"

</TABLE>
<STRONG>-</STRONG> in the <IT>default</IT> indicates no default<BR>
<STRONG>+</STRONG> in the <IT>default</IT> indicates the field is mandatory<BR>

<H4>Description of Options</H4>
<H5>
	IgnoreStatus
</H5>
HTTP response codes which should not be considered errors. This field
	takes the form of a sequence of 3 digit decimal codes seperated by
	spaces.
	<STRONG>NOTE:</STRONG> Typically the values 0 and 200 will always be 
	included.
<H5>
	&lt;nnn&gt;
</H5>
This directive is used to specify the error message virtual path to be set
for a specific status code.

<H5>
	DefaultMessage
</H5>
The default error message. This is used for status codes which have
	not been specified as ignorable, but which have no error virtual path
	explicitly defined.

<H5>
	Action
</H5>
A Pi3Expression that will be evaulated if the error status code is mapped.

Phase:
	MAPPING

Returns:
	PIAPI_CONTINUE in all non-error cases, whether or not an error 
	virtual path was set.
	PIAPI_ERROR and PIAPI_ABORT respectively for generic and severe
	error conditions.

Example:
	<PRE>
	&lt;Object&gt;
		Name MapToErrorDocument
		Class MapToErrorDocumentClass
		IgnoreStatus "0 200"
	&lt;/Object&gt;

	&lt;Object&gt;
		...
		Mapping MapToErrorDocument DefaultMessage="/errors/Unknown.html" 403="/errors/Forbidden.html"
		...
	&lt;/Object&gt;

	</PRE>
/*___+++HTMLDOC_END+++___*/
#endif

/*____________________________________________________________________________*\
 *
 Class:
 Description:
\*____________________________________________________________________________*/
class MapToErrorDocument : public HandlerBaseHTTP
{
private:
	/* --- forbid copy constructor --- */
	MapToErrorDocument( const MapToErrorDocument &t )
	: HandlerBaseHTTP( t )
		{ assert( 0 ); };

	/* ---
	Configuration data
	--- */
	DblList lIgnoreCodes;
	DblList lMapToErrorVirtualPaths;
	PIString sDefaultVirtualPath;
	Pi3Expression *pExpr;

protected:
	int Parameter( const char *pVariable, const char *pValue,
		const char *pWhere )
		{
		assert( pVariable && pValue );
		PIOStrStream os;
		os << pWhere << "MapToErrorDocument: ";
		if ( !PIUtil_stricmp( KEY_CONF_IGNORESTATUS, pVariable ) )
			{
			StringTokenizer tTokens( pValue, " " );
			for( int i=0; i<tTokens.NumTokens(); i++)
				{
				lIgnoreCodes.Append( (DblList::type)
					atoi( tTokens.GetToken( i ) ) );
				};
			}
		else if ( !PIUtil_stricmp( KEY_CONF_DEFAULTMESSAGE, pVariable ) )
			{
			sDefaultVirtualPath = pValue;
			}
		else if ( !PIUtil_stricmp( KEY_CONF_ACTION, pVariable ) )
			{
			if ( pExpr )
				{
				os << "'Action' make only be specified once." << endl;
				CONFIG_ERR( Object(), os.str() );
				return 0;
				};
			Pi3String *pError = Pi3String_new( 0 );
			Pi3Expression *pTmp = Pi3Expression_new( pValue, 0, pError );
			if ( !pTmp )
				{
				os << "Error in action expression:" << 
					Pi3String_getPtr( pError ) << endl;
				CONFIG_ERR( Object(), os.str() );
				Pi3String_delete( pError );
				return 0;
				};
			Pi3String_delete( pError );
			pExpr = pTmp;
			}
		else if ( isdigit( *pVariable ) )
			{
			int iTmp = atoi( pVariable );
			lMapToErrorVirtualPaths.Append( (DblList::type) 
				PI_NEW( ErrorMap( iTmp, pValue ) ) ); 
			}
		else
			{
			os << "Unknown directive '" << pVariable <<
				"'" << ends;
			CONFIG_ERR( Object(), os.str() );
			return 0;
			};

		return 1;
		};

public:
	MapToErrorDocument( PIObject *pObject, int iArgc, const char *ppArgv[] )
	:	HandlerBaseHTTP( pObject ),
		pExpr( 0 )
		{
		ReadParameters( iArgc, ppArgv );

		/* --- 
		Make sure there's a default	
		--- */
		if ( sDefaultVirtualPath==PIString::Empty() )
			{
			CONFIG_ERR( Object(), "MapToErrorDocument: 'Default' not defined" );
			SetOK( 0 );
			return;
			};
		};

	virtual ~MapToErrorDocument()
		{
		for( DblListIterator i( lMapToErrorVirtualPaths ); !i.BadIndex(); i++)
			{
			PI_DELETE( (ErrorMap *)i.Current() );
			};
		if ( pExpr )
			{ Pi3Expression_delete( pExpr ); };
		};

	/* -------------- +++++++++++++++++++++++++++++++ ------------------ *\
			
							Handle the request

	\* -------------- +++++++++++++++++++++++++++++++ ------------------ */
	int Handle( int iPhase, PIHTTP &tPIHTTP, PIIOBuffer &/* tB */ )
		{
		if ( iPhase!=PH_MAPPING )
			{
			HTTPCore_logError( &tPIHTTP, "MapToErrorDocument: \
Configuration error, \
'MapToErrorDocument' handler may only be used for 'MAPPING' phase, not '%s' \
phase.",
			HTTPUtil_phaseNumberToName( iPhase ) );
			return PIAPI_ERROR;
			};

		PIDB *pR = tPIHTTP.pResponseDB;
		PIDB *pQ = tPIHTTP.pRequestDB;

		int iStatus = tPIHTTP.iStatus;

		/* ---
		See is this a status code that we should ignore
		--- */
		for( DblListIterator i( lIgnoreCodes ); !i.BadIndex(); i++ )
			{
			if ( iStatus==(int)i.Current() )	
				{ return PIAPI_CONTINUE; };
			};

		/* ---
		Find the mapping with the appropriate status
		--- */
		const char *pErrorPath = 0;
		for( DblListIterator j( lMapToErrorVirtualPaths ); !j.BadIndex(); j++ )
			{
			ErrorMap *pMap = (ErrorMap *)j.Current();
			assert( pMap );
			if ( iStatus==pMap->iStatus )	
				{
				pErrorPath = pMap->sVirtualPath;
				break;
				};
			};

		/* ---
		Assign default if necessary
		--- */
		if ( !pErrorPath )
			{
			pErrorPath = sDefaultVirtualPath;
			};

		/* ---
		Save old path
		--- */
		void *pPath = (void *)PIDB_lookup( pR, PIDBTYPE_STRING,
			KEY_INT_PATH, 0);
		PIDB_add( pR, PIDBTYPE_STRING, KEY_INT_OLDPATH, pPath, 0);

		/* ---	
		Change the path, and modify other headers 
		--- */
		PIDB_replace( pR, PIDBTYPE_STRING, KEY_INT_PATH, (void *)pErrorPath, 0);
		PIDB_replace( pQ, PIDBTYPE_RFC822, KEY_HTTP_IFMODIFIEDSINCE, 0, 0);
		PIDB_replace( pQ, PIDBTYPE_OPAQUE, KEY_HTTP_METHOD, (void *)MD_GET, 0);

		/* ---
		Perform action if specified
		--- */
		if ( pExpr )
			{ Pi3Expression_write( pExpr, &tPIHTTP, 0, 0, 0 ); };

		/* --- done --- */
		return PIAPI_CONTINUE;
		};

};

/*____________________________________________________________________________*\
 *
 Function:
 Synopsis:
 Description:
\*____________________________________________________________________________*/
PUBLIC_PIAPI int MapToErrorDocument_constructor( PIObject *pObj,
	int iArgc, const char *ppArgv[] )
{
	return HandlerBaseHTTP_constructor( pObj, PI_NEW( MapToErrorDocument( pObj,
		iArgc, ppArgv ) ) );
}

#if 0
/*___+++CNF_BEGIN+++___*/
	<Class>
		Name MapToErrorDocumentClass
		Type LogicExtension
		Library HTTP
		OnClassLoad HandlerBaseHTTP_onClassLoad
		Constructor MapToErrorDocument_constructor
		CopyConstructor HandlerBaseHTTP_copyConstructor
		Destructor HandlerBaseHTTP_destructor
		Execute HandlerBaseHTTP_execute
	</Class>

	<Object>
		Name MapToErrorDocument
		Class MapToErrorDocumentClass
	</Object>

/*___+++CNF_END+++___*/
#endif