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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* 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.
*/
/*
* $Id: MemBufInputSource.hpp 568078 2007-08-21 11:43:25Z amassari $
*/
#if !defined(MEMBUFINPUTSOURCE_HPP)
#define MEMBUFINPUTSOURCE_HPP
#include <xercesc/sax/InputSource.hpp>
XERCES_CPP_NAMESPACE_BEGIN
class BinInputStream;
/**
* This class is a derivative of the standard InputSource class. It provides
* for the parser access to data stored in a memory buffer. The type of
* buffer and its host specific attributes are of little concern here. The
* only real requirement is that the memory be readable by the current
* process.
*
* Note that the memory buffer size is expressed in <b>bytes</b>, not in
* characters. If you pass it text data, you must account for the bytes
* per character when indicating the buffer size.
*
* As with all InputSource derivatives. The primary objective of an input
* source is to create an input stream via which the parser can spool in
* data from the referenced source. In this case, there are two options
* available.
*
* The passed buffer can be adopted or merely referenced. If it is adopted,
* then it must be dynamically allocated and will be destroyed when the
* input source is destroyed (no reference counting!.) If not adopted, the
* caller must insure that it remains valid until the input source object
* is destroyed.
*
* The other option indicates whether each stream created for this input
* source should get its own copy of the data, or whether it should just
* stream the data directly from this object's copy of the data. The same
* rules apply here, in that the buffer must either be copied by the
* stream or it must remain valid until the stream is destroyed.
*/
class XMLPARSER_EXPORT MemBufInputSource : public InputSource
{
public :
// -----------------------------------------------------------------------
// Constructors and Destructor
// -----------------------------------------------------------------------
/** @name Constructors */
//@{
/**
* A memory buffer input source is constructed from a buffer of byte
* data, and the count of bytes in that buffer. The parser will parse
* from this memory buffer until it has eaten the indicated number of
* bytes.
*
* Note that the system id provided serves two purposes. Firstly it is
* going to be displayed in error messages as the source of the error.
* And secondly, any entities which are refered to from this entity
* via relative paths/URLs will be relative to this fake system id.
*
* @param srcDocBytes The actual data buffer to be parsed from.
* @param byteCount The count of bytes (not characters, bytes!)
* in the buffer.
* @param bufId A fake system id for the buffer.
* @param adoptBuffer Indicates whether this object should adopt
* the buffer (i.e. become responsible for
* deletion) or just
* use it in place.
* @param manager Pointer to the memory manager to be used to
* allocate objects.
*/
MemBufInputSource
(
const XMLByte* const srcDocBytes
, const unsigned int byteCount
, const XMLCh* const bufId
, const bool adoptBuffer = false
, MemoryManager* const manager = XMLPlatformUtils::fgMemoryManager
);
/**
* This constructor is identical to the previous one, except that it takes
* the fake system id in local code page form and transcodes it internally.
*/
MemBufInputSource
(
const XMLByte* const srcDocBytes
, const unsigned int byteCount
, const char* const bufId
, const bool adoptBuffer = false
, MemoryManager* const manager = XMLPlatformUtils::fgMemoryManager
);
//@}
/** @name Destructor */
//@{
/**
* If the buffer was adopted, the copy made during construction is deleted
* at this point.
*/
~MemBufInputSource();
//@}
// -----------------------------------------------------------------------
// Virtual input source interface
// -----------------------------------------------------------------------
/** @name Virtual methods */
//@{
/**
* This method will return a binary input stream derivative that will
* parse from the memory buffer. If setCopyBufToStream() has been set,
* then the stream will make its own copy. Otherwise, it will use the
* buffer as is (in which case it must remain valid until the stream
* is no longer in use, i.e. the parse completes.)
*
* @return A dynamically allocated binary input stream derivative that
* can parse from the memory buffer.
*/
BinInputStream* makeStream() const;
//@}
// -----------------------------------------------------------------------
// Setter methods
// -----------------------------------------------------------------------
/** @name Setter methods */
//@{
/**
* By default, for safety's sake, each newly created stream from this
* input source will make its own copy of the buffer to stream from. This
* avoids having to deal with aliasing of the buffer for simple work. But,
* for higher performance applications or for large buffers, this is
* obviously not optimal.
*
* In such cases, you can call this method to turn off that default
* action. Once turned off, the streams will just get a pointer to the
* buffer and parse directly from that. In this case, you must insure that
* the buffer remains valid for as long as any parse events are still
* using it.
*
* @param newState The new boolean flag state to set.
*/
void setCopyBufToStream(const bool newState);
/**
* This methods allows the MemBufInputSource to be used for more than
* one input source, instead of destructing/constructing another
* MemBufInputSource.
*
* @param srcDocBytes The actual data buffer to be parsed from.
* @param byteCount The count of bytes (not characters, bytes!)
* in the buffer.
*/
void resetMemBufInputSource(const XMLByte* const srcDocBytes
, const unsigned int byteCount);
//@}
private :
// -----------------------------------------------------------------------
// Unimplemented constructors and operators
// -----------------------------------------------------------------------
MemBufInputSource(const MemBufInputSource&);
MemBufInputSource& operator=(const MemBufInputSource&);
// -----------------------------------------------------------------------
// Private data members
//
// fAdopted
// Indicates whether the buffer is adopted or not. If so, then it
// is destroyed when the input source is destroyed.
//
// fByteCount
// The size of the source document.
//
// fCopyBufToStream
// This defaults to true (the safe option), which causes it to
// give a copy of the buffer to any streams it creates. If you set
// it to false, it will allow the streams to just reference the
// buffer (in which case this input source must stay alive as long
// as the buffer is in use by the stream.)
//
// fSrcBytes
// The source memory buffer that is being spooled from. Whether it
// belongs to the this input source or not is controlled by the
// fAdopted flag.
// -----------------------------------------------------------------------
bool fAdopted;
unsigned int fByteCount;
bool fCopyBufToStream;
const XMLByte* fSrcBytes;
};
inline void MemBufInputSource::setCopyBufToStream(const bool newState)
{
fCopyBufToStream = newState;
}
XERCES_CPP_NAMESPACE_END
#endif