gdcmParser.h

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00001 /*=========================================================================
00002 
00003   Program: GDCM (Grassroots DICOM). A DICOM library
00004   Module:  $URL$
00005 
00006   Copyright (c) 2006-2010 Mathieu Malaterre
00007   All rights reserved.
00008   See Copyright.txt or http://gdcm.sourceforge.net/Copyright.html for details.
00009 
00010      This software is distributed WITHOUT ANY WARRANTY; without even
00011      the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
00012      PURPOSE.  See the above copyright notice for more information.
00013 
00014 =========================================================================*/
00015 
00016 #ifndef GDCMPARSER_H
00017 #define GDCMPARSER_H
00018 
00019 #include "gdcmTag.h"
00020 #error do not use
00021 #include "gdcmByteBuffer.h"
00022 
00023 #include <fstream> // std::ifstream
00024 
00025 namespace gdcm
00026 {
00033 class GDCM_EXPORT Parser /*: private IStream*/
00034 {
00035 public:
00036   typedef enum {
00037     NoError,
00038     NoMemoryError,
00039     SyntaxError,
00040     NoElementsError,
00041     TagMismatchError,
00042     DuplicateAttributeError,
00043     JunkAfterDocElementError,
00044     UndefinedEntityError,
00045     UnexpectedStateError
00046   } ErrorType;
00047 
00048   Parser() : UserData(0),Buffer(),ErrorCode(NoError) {}
00049   ~Parser() {}
00050 
00051   // Parse some more of the document. The string s is a buffer containing 
00052   // part (or perhaps all) of the document. The number of bytes of s that 
00053   // are part of the document is indicated by len. This means that s 
00054   // doesn't have to be null terminated. It also means that if len is 
00055   // larger than the number of bytes in the block of memory that s points 
00056   // at, then a memory fault is likely. The isFinal parameter informs the 
00057   // parser that this is the last piece of the document. Frequently, the 
00058   // last piece is empty (i.e. len is zero.) If a parse error occurred, 
00059   // it returns 0. Otherwise it returns a non-zero value.
00060   bool Parse(const char* s, int len, bool isFinal);
00061 
00062   // Set handlers for start and end tags. Attributes are passed to the 
00063   // start handler as a pointer to a vector of char pointers. Each 
00064   // attribute seen in a start (or empty) tag occupies 2 consecutive places
00065   // in this vector: the attribute name followed by the attribute value. 
00066   // These pairs are terminated by a null pointer.
00067   typedef void (*StartElementHandler) (void *userData,
00068                                        const Tag &tag,
00069                                        const char *atts[]);
00070   typedef void (*EndElementHandler) (void *userData, const Tag &name);
00071   void SetElementHandler(StartElementHandler start, EndElementHandler end);
00072 
00073   // Return what type of error has occurred.
00074   ErrorType GetErrorCode() const;
00075 
00076   // Return a string describing the error corresponding to code. 
00077   // The code should be one of the enums that can be returned from 
00078   // GetErrorCode.
00079   static const char *GetErrorString(ErrorType const &err);
00080 
00081   // Return the byte offset of the position.
00082   unsigned long GetCurrentByteIndex() const;
00083 
00084   // Miscellaneous functions
00085 
00086   // The functions in this section either obtain state information from 
00087   // the parser or can be used to dynamically set parser options.
00088 
00089   // This sets the user data pointer that gets passed to handlers.
00090   void SetUserData(void *userData);
00091 
00092   // This returns the user data pointer that gets passed to handlers. 
00093   void * GetUserData() const;
00094 
00095 protected:
00096 
00097   // This is just like Parse, except in this case expat provides the buffer.
00098   // By obtaining the buffer from expat with the GetBuffer function, 
00099   // the application can avoid double copying of the input.
00100   bool ParseBuffer(int len, bool isFinal);
00101 
00102   // Obtain a buffer of size len to read a piece of the document into. 
00103   // A NULL value is returned if expat can't allocate enough memory for 
00104   // this buffer. This has to be called prior to every call to ParseBuffer.
00105   char *GetBuffer(int len);
00106 
00107   ErrorType Process();
00108 
00109 private:
00110   std::ifstream Stream;
00111   void* UserData;
00112   ByteBuffer Buffer;
00113   ErrorType ErrorCode;
00114 
00115   StartElementHandler StartElement;
00116   EndElementHandler EndElement;
00117 };
00118 
00119 } // end namespace gdcm
00120 
00121 #endif //GDCMPARSER_H

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