www.pudn.com > mitab.rar > cpl_minixml.cpp
/********************************************************************** * $Id: cpl_minixml.cpp,v 1.34 2005/03/09 17:07:25 fwarmerdam Exp $ * * Project: CPL - Common Portability Library * Purpose: Implementation of MiniXML Parser and handling. * Author: Frank Warmerdam, warmerdam@pobox.com * ********************************************************************** * Copyright (c) 2001, Frank Warmerdam * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. ********************************************************************** * * Independent Security Audit 2003/04/05 Andrey Kiselev: * Completed audit of this module. Any documents may be parsed without * buffer overflows and stack corruptions. * * Security Audit 2003/03/28 warmerda: * Completed security audit. I believe that this module may be safely used * to parse, and serialize arbitrary documents provided by a potentially * hostile source. * * $Log: cpl_minixml.cpp,v $ * Revision 1.34 2005/03/09 17:07:25 fwarmerdam * added CPLSearchXMLNode * * Revision 1.33 2005/01/17 17:01:56 fwarmerdam * ensure that namespace stripping apply to attributes * * Revision 1.32 2004/10/21 18:59:00 fwarmerdam * Ensure that an empty path in CPLGetXMLValue() means the current node. * * Revision 1.31 2004/08/11 18:42:00 warmerda * fix quirks with CPLSetXMLValue() * * Revision 1.30 2004/03/31 17:11:41 warmerda * fixed return value of CPLCreateXMLElementAndValue() * * Revision 1.29 2004/01/29 17:01:51 warmerda * Added reference to spec. * * Revision 1.28 2004/01/29 15:29:28 warmerda * Added CPLCleanXMLElementName * * Revision 1.27 2003/12/04 15:46:51 warmerda * Added CPLAddXMLSibling() * * Revision 1.26 2003/12/04 15:19:43 warmerda * Added "=" support for "sidesearching" in a document. * * Revision 1.25 2003/11/07 19:40:19 warmerda * ensure CPLGetXMLValue() works for nodes with attributes * * Revision 1.24 2003/11/05 20:14:21 warmerda * added lots of documentation * * Revision 1.23 2003/05/21 03:32:43 warmerda * expand tabs * * Revision 1.22 2003/04/05 07:12:25 dron * Completed security audit. * * Revision 1.21 2003/03/28 17:38:39 warmerda * Added NULL check in CPLParseXMLString(). * * Revision 1.20 2003/03/28 05:05:18 warmerda * Completed security audit. Several bugs related to possible buffer * overruns correct, notably with regard to CPLError() calls. * * Revision 1.19 2003/03/27 18:12:41 warmerda * Added NULL pszNameSpace support in namespace stripper (all namespaces). * Added XML file read/write functions. * * Revision 1.18 2003/03/24 16:47:30 warmerda * Added CPLStripXMLNamespace(). * CPLAddXMLChild() will now ensure that attributes are inserted before * non-attributes nodes. * * Revision 1.17 2003/02/14 18:44:29 warmerda * proper tokens may include a dash * * Revision 1.16 2002/11/16 20:42:40 warmerda * improved inline comments * * Revision 1.15 2002/11/16 20:38:34 warmerda * added support for literals like DOCTYPE * * Revision 1.14 2002/07/16 15:06:26 warmerda * ensure that attributes are serialized properly regardless of their order * * Revision 1.13 2002/07/09 20:25:25 warmerda * expand tabs * * Revision 1.12 2002/05/28 18:54:05 warmerda * added escaping/unescaping support * * Revision 1.11 2002/05/24 04:09:10 warmerda * added clone and SetXMLValue functions * * Revision 1.10 2002/04/01 16:08:21 warmerda * allow periods in tokens * * Revision 1.9 2002/03/07 22:19:20 warmerda * don't do operations within CPLAssert(), in UnreadChar() * * Revision 1.8 2002/03/05 14:26:57 warmerda * expanded tabs * * Revision 1.7 2002/01/23 20:45:05 warmerda * handle and comment elements * * Revision 1.6 2002/01/22 18:54:48 warmerda * ensure text is property initialized when serializing * * Revision 1.5 2002/01/16 03:58:51 warmerda * support single quotes as well as double quotes * * Revision 1.4 2001/12/06 18:13:49 warmerda * added CPLAddXMLChild and CPLCreateElmentAndValue * * Revision 1.3 2001/11/16 21:20:16 warmerda * fixed typo * * Revision 1.2 2001/11/16 20:29:58 warmerda * fixed lost char in normal CString tokens * * Revision 1.1 2001/11/16 15:39:48 warmerda * New */ #include#include "cpl_minixml.h" #include "cpl_error.h" #include "cpl_conv.h" #include "cpl_string.h" CPL_CVSID("$Id: cpl_minixml.cpp,v 1.34 2005/03/09 17:07:25 fwarmerdam Exp $"); typedef enum { TNone, TString, TOpen, TClose, TEqual, TToken, TSlashClose, TQuestionClose, TComment, TLiteral } TokenType; typedef struct { const char *pszInput; int nInputOffset; int nInputLine; int bInElement; TokenType eTokenType; char *pszToken; int nTokenMaxSize; int nTokenSize; int nStackMaxSize; int nStackSize; CPLXMLNode **papsStack; CPLXMLNode *psFirstNode; } ParseContext; /************************************************************************/ /* ReadChar() */ /************************************************************************/ static char ReadChar( ParseContext *psContext ) { char chReturn; chReturn = psContext->pszInput[psContext->nInputOffset++]; if( chReturn == '\0' ) psContext->nInputOffset--; else if( chReturn == 10 ) psContext->nInputLine++; return chReturn; } /************************************************************************/ /* UnreadChar() */ /************************************************************************/ static void UnreadChar( ParseContext *psContext, char chToUnread ) { if( chToUnread == '\0' ) { /* do nothing */ } else { CPLAssert( chToUnread == psContext->pszInput[psContext->nInputOffset-1] ); psContext->nInputOffset--; if( chToUnread == 10 ) psContext->nInputLine--; } } /************************************************************************/ /* AddToToken() */ /************************************************************************/ static void AddToToken( ParseContext *psContext, char chNewChar ) { if( psContext->pszToken == NULL ) { psContext->nTokenMaxSize = 10; psContext->pszToken = (char *) CPLMalloc(psContext->nTokenMaxSize); } else if( psContext->nTokenSize >= psContext->nTokenMaxSize - 2 ) { psContext->nTokenMaxSize *= 2; psContext->pszToken = (char *) CPLRealloc(psContext->pszToken,psContext->nTokenMaxSize); } psContext->pszToken[psContext->nTokenSize++] = chNewChar; psContext->pszToken[psContext->nTokenSize] = '\0'; } /************************************************************************/ /* ReadToken() */ /************************************************************************/ static TokenType ReadToken( ParseContext *psContext ) { char chNext; psContext->nTokenSize = 0; psContext->pszToken[0] = '\0'; chNext = ReadChar( psContext ); while( isspace(chNext) ) chNext = ReadChar( psContext ); /* -------------------------------------------------------------------- */ /* Handle comments. */ /* -------------------------------------------------------------------- */ if( chNext == '<' && EQUALN(psContext->pszInput+psContext->nInputOffset,"!--",3) ) { psContext->eTokenType = TComment; // Skip "!--" characters ReadChar(psContext); ReadChar(psContext); ReadChar(psContext); while( !EQUALN(psContext->pszInput+psContext->nInputOffset,"-->",3) && (chNext = ReadChar(psContext)) != '\0' ) AddToToken( psContext, chNext ); // Skip "-->" characters ReadChar(psContext); ReadChar(psContext); ReadChar(psContext); } /* -------------------------------------------------------------------- */ /* Handle DOCTYPE or other literals. */ /* -------------------------------------------------------------------- */ else if( chNext == '<' && EQUALN(psContext->pszInput+psContext->nInputOffset,"!DOCTYPE",8) ) { int bInQuotes = FALSE; psContext->eTokenType = TLiteral; AddToToken( psContext, '<' ); do { chNext = ReadChar(psContext); if( chNext == '\0' ) { CPLError( CE_Failure, CPLE_AppDefined, "Parse error in DOCTYPE on or before line %d, " "reached end of file without '>'.", psContext->nInputLine ); break; } if( chNext == '\"' ) bInQuotes = !bInQuotes; if( chNext == '>' && !bInQuotes ) { AddToToken( psContext, '>' ); break; } AddToToken( psContext, chNext ); } while( TRUE ); } /* -------------------------------------------------------------------- */ /* Simple single tokens of interest. */ /* -------------------------------------------------------------------- */ else if( chNext == '<' && !psContext->bInElement ) { psContext->eTokenType = TOpen; psContext->bInElement = TRUE; } else if( chNext == '>' && psContext->bInElement ) { psContext->eTokenType = TClose; psContext->bInElement = FALSE; } else if( chNext == '=' && psContext->bInElement ) { psContext->eTokenType = TEqual; } else if( chNext == '\0' ) { psContext->eTokenType = TNone; } /* -------------------------------------------------------------------- */ /* Handle the /> token terminator. */ /* -------------------------------------------------------------------- */ else if( chNext == '/' && psContext->bInElement && psContext->pszInput[psContext->nInputOffset] == '>' ) { chNext = ReadChar( psContext ); CPLAssert( chNext == '>' ); psContext->eTokenType = TSlashClose; psContext->bInElement = FALSE; } /* -------------------------------------------------------------------- */ /* Handle the ?> token terminator. */ /* -------------------------------------------------------------------- */ else if( chNext == '?' && psContext->bInElement && psContext->pszInput[psContext->nInputOffset] == '>' ) { chNext = ReadChar( psContext ); CPLAssert( chNext == '>' ); psContext->eTokenType = TQuestionClose; psContext->bInElement = FALSE; } /* -------------------------------------------------------------------- */ /* Collect a quoted string. */ /* -------------------------------------------------------------------- */ else if( psContext->bInElement && chNext == '"' ) { psContext->eTokenType = TString; while( (chNext = ReadChar(psContext)) != '"' && chNext != '\0' ) AddToToken( psContext, chNext ); if( chNext != '"' ) { psContext->eTokenType = TNone; CPLError( CE_Failure, CPLE_AppDefined, "Parse error on line %d, reached EOF before closing quote.", psContext->nInputLine ); } /* Do we need to unescape it? */ if( strchr(psContext->pszToken,'&') != NULL ) { int nLength; char *pszUnescaped = CPLUnescapeString( psContext->pszToken, &nLength, CPLES_XML ); strcpy( psContext->pszToken, pszUnescaped ); CPLFree( pszUnescaped ); psContext->nTokenSize = strlen(psContext->pszToken ); } } else if( psContext->bInElement && chNext == '\'' ) { psContext->eTokenType = TString; while( (chNext = ReadChar(psContext)) != '\'' && chNext != '\0' ) AddToToken( psContext, chNext ); if( chNext != '\'' ) { psContext->eTokenType = TNone; CPLError( CE_Failure, CPLE_AppDefined, "Parse error on line %d, reached EOF before closing quote.", psContext->nInputLine ); } /* Do we need to unescape it? */ if( strchr(psContext->pszToken,'&') != NULL ) { int nLength; char *pszUnescaped = CPLUnescapeString( psContext->pszToken, &nLength, CPLES_XML ); strcpy( psContext->pszToken, pszUnescaped ); CPLFree( pszUnescaped ); psContext->nTokenSize = strlen(psContext->pszToken ); } } /* -------------------------------------------------------------------- */ /* Collect an unquoted string, terminated by a open angle */ /* bracket. */ /* -------------------------------------------------------------------- */ else if( !psContext->bInElement ) { psContext->eTokenType = TString; AddToToken( psContext, chNext ); while( (chNext = ReadChar(psContext)) != '<' && chNext != '\0' ) AddToToken( psContext, chNext ); UnreadChar( psContext, chNext ); /* Do we need to unescape it? */ if( strchr(psContext->pszToken,'&') != NULL ) { int nLength; char *pszUnescaped = CPLUnescapeString( psContext->pszToken, &nLength, CPLES_XML ); strcpy( psContext->pszToken, pszUnescaped ); CPLFree( pszUnescaped ); psContext->nTokenSize = strlen(psContext->pszToken ); } } /* -------------------------------------------------------------------- */ /* Collect a regular token terminated by white space, or */ /* special character(s) like an equal sign. */ /* -------------------------------------------------------------------- */ else { psContext->eTokenType = TToken; /* add the first character to the token regardless of what it is */ AddToToken( psContext, chNext ); for( chNext = ReadChar(psContext); (chNext >= 'A' && chNext <= 'Z') || (chNext >= 'a' && chNext <= 'z') || chNext == '-' || chNext == '_' || chNext == '.' || chNext == ':' || (chNext >= '0' && chNext <= '9'); chNext = ReadChar(psContext) ) { AddToToken( psContext, chNext ); } UnreadChar(psContext, chNext); } return psContext->eTokenType; } /************************************************************************/ /* PushNode() */ /************************************************************************/ static void PushNode( ParseContext *psContext, CPLXMLNode *psNode ) { if( psContext->nStackMaxSize <= psContext->nStackSize ) { psContext->nStackMaxSize += 10; psContext->papsStack = (CPLXMLNode **) CPLRealloc(psContext->papsStack, sizeof(CPLXMLNode*) * psContext->nStackMaxSize); } psContext->papsStack[psContext->nStackSize++] = psNode; } /************************************************************************/ /* AttachNode() */ /* */ /* Attach the passed node as a child of the current node. */ /* Special handling exists for adding siblings to psFirst if */ /* there is nothing on the stack. */ /************************************************************************/ static void AttachNode( ParseContext *psContext, CPLXMLNode *psNode ) { if( psContext->psFirstNode == NULL ) psContext->psFirstNode = psNode; else if( psContext->nStackSize == 0 ) { CPLXMLNode *psSibling; psSibling = psContext->psFirstNode; while( psSibling->psNext != NULL ) psSibling = psSibling->psNext; psSibling->psNext = psNode; } else if( psContext->papsStack[psContext->nStackSize-1]->psChild == NULL ) { psContext->papsStack[psContext->nStackSize-1]->psChild = psNode; } else { CPLXMLNode *psSibling; psSibling = psContext->papsStack[psContext->nStackSize-1]->psChild; while( psSibling->psNext != NULL ) psSibling = psSibling->psNext; psSibling->psNext = psNode; } } /************************************************************************/ /* CPLParseXMLString() */ /************************************************************************/ /** * Parse an XML string into tree form. * * The passed document is parsed into a CPLXMLNode tree representation. * If the document is not well formed XML then NULL is returned, and errors * are reported via CPLError(). No validation beyond wellformedness is * done. The CPLParseXMLFile() convenience function can be used to parse * from a file. * * The returned document tree is is owned by the caller and should be freed * with CPLDestroyXMLNode() when no longer needed. * * If the document has more than one "root level" element then those after the * first will be attached to the first as siblings (via the psNext pointers) * even though there is no common parent. A document with no XML structure * (no angle brackets for instance) would be considered well formed, and * returned as a single CXT_Text node. * * @param pszString the document to parse. * * @return parsed tree or NULL on error. */ CPLXMLNode *CPLParseXMLString( const char *pszString ) { ParseContext sContext; CPLErrorReset(); if( pszString == NULL ) { CPLError( CE_Failure, CPLE_AppDefined, "CPLParseXMLString() called with NULL pointer." ); return NULL; } /* -------------------------------------------------------------------- */ /* Initialize parse context. */ /* -------------------------------------------------------------------- */ sContext.pszInput = pszString; sContext.nInputOffset = 0; sContext.nInputLine = 0; sContext.bInElement = FALSE; sContext.pszToken = NULL; sContext.nTokenMaxSize = 0; sContext.nTokenSize = 0; sContext.eTokenType = TNone; sContext.nStackMaxSize = 0; sContext.nStackSize = 0; sContext.papsStack = NULL; sContext.psFirstNode = NULL; /* ensure token is initialized */ AddToToken( &sContext, ' ' ); /* ==================================================================== */ /* Loop reading tokens. */ /* ==================================================================== */ while( ReadToken( &sContext ) != TNone ) { /* -------------------------------------------------------------------- */ /* Create a new element. */ /* -------------------------------------------------------------------- */ if( sContext.eTokenType == TOpen ) { CPLXMLNode *psElement; if( ReadToken(&sContext) != TToken ) { CPLError( CE_Failure, CPLE_AppDefined, "Line %d: Didn't find element token after open angle bracket.", sContext.nInputLine ); break; } if( sContext.pszToken[0] != '/' ) { psElement = CPLCreateXMLNode( NULL, CXT_Element, sContext.pszToken ); AttachNode( &sContext, psElement ); PushNode( &sContext, psElement ); } else { if( sContext.nStackSize == 0 || !EQUAL(sContext.pszToken+1, sContext.papsStack[sContext.nStackSize-1]->pszValue) ) { CPLError( CE_Failure, CPLE_AppDefined, "Line %d: <%.500s> doesn't have matching <%.500s>.", sContext.nInputLine, sContext.pszToken, sContext.pszToken+1 ); break; } else { if( ReadToken(&sContext) != TClose ) { CPLError( CE_Failure, CPLE_AppDefined, "Line %d: Missing close angle bracket after <%.500s.", sContext.nInputLine, sContext.pszToken ); break; } /* pop element off stack */ sContext.nStackSize--; } } } /* -------------------------------------------------------------------- */ /* Add an attribute to a token. */ /* -------------------------------------------------------------------- */ else if( sContext.eTokenType == TToken ) { CPLXMLNode *psAttr; psAttr = CPLCreateXMLNode(NULL, CXT_Attribute, sContext.pszToken); AttachNode( &sContext, psAttr ); if( ReadToken(&sContext) != TEqual ) { CPLError( CE_Failure, CPLE_AppDefined, "Line %d: Didn't find expected '=' for value of attribute '%.500s'.", sContext.nInputLine, psAttr->pszValue ); break; } if( ReadToken(&sContext) != TString && sContext.eTokenType != TToken ) { CPLError( CE_Failure, CPLE_AppDefined, "Line %d: Didn't find expected attribute value.", sContext.nInputLine ); break; } CPLCreateXMLNode( psAttr, CXT_Text, sContext.pszToken ); } /* -------------------------------------------------------------------- */ /* Close the start section of an element. */ /* -------------------------------------------------------------------- */ else if( sContext.eTokenType == TClose ) { if( sContext.nStackSize == 0 ) { CPLError( CE_Failure, CPLE_AppDefined, "Line %d: Found unbalanced '>'.", sContext.nInputLine ); break; } } /* -------------------------------------------------------------------- */ /* Close the start section of an element, and pop it */ /* immediately. */ /* -------------------------------------------------------------------- */ else if( sContext.eTokenType == TSlashClose ) { if( sContext.nStackSize == 0 ) { CPLError( CE_Failure, CPLE_AppDefined, "Line %d: Found unbalanced '/>'.", sContext.nInputLine ); break; } sContext.nStackSize--; } /* -------------------------------------------------------------------- */ /* Close the start section of a element, and pop it */ /* immediately. */ /* -------------------------------------------------------------------- */ else if( sContext.eTokenType == TQuestionClose ) { if( sContext.nStackSize == 0 ) { CPLError( CE_Failure, CPLE_AppDefined, "Line %d: Found unbalanced '?>'.", sContext.nInputLine ); break; } else if( sContext.papsStack[sContext.nStackSize-1]->pszValue[0] != '?' ) { CPLError( CE_Failure, CPLE_AppDefined, "Line %d: Found '?>' without matching 'pszValue ); } /* -------------------------------------------------------------------- */ /* Cleanup */ /* -------------------------------------------------------------------- */ CPLFree( sContext.pszToken ); if( sContext.papsStack != NULL ) CPLFree( sContext.papsStack ); if( CPLGetLastErrorType() != CE_None ) { CPLDestroyXMLNode( sContext.psFirstNode ); sContext.psFirstNode = NULL; } return sContext.psFirstNode; } /************************************************************************/ /* _GrowBuffer() */ /************************************************************************/ static void _GrowBuffer( unsigned int nNeeded, char **ppszText, unsigned int *pnMaxLength ) { if( nNeeded+1 >= *pnMaxLength ) { *pnMaxLength = MAX(*pnMaxLength * 2,nNeeded+1); *ppszText = (char *) CPLRealloc(*ppszText, *pnMaxLength); } } /************************************************************************/ /* CPLSerializeXMLNode() */ /************************************************************************/ static void CPLSerializeXMLNode( CPLXMLNode *psNode, int nIndent, char **ppszText, unsigned int *pnLength, unsigned int *pnMaxLength ) { if( psNode == NULL ) return; /* -------------------------------------------------------------------- */ /* Ensure the buffer is plenty large to hold this additional */ /* string. */ /* -------------------------------------------------------------------- */ *pnLength += strlen(*ppszText + *pnLength); _GrowBuffer( strlen(psNode->pszValue) + *pnLength + 40 + nIndent, ppszText, pnMaxLength ); /* -------------------------------------------------------------------- */ /* Text is just directly emitted. */ /* -------------------------------------------------------------------- */ if( psNode->eType == CXT_Text ) { char *pszEscaped = CPLEscapeString( psNode->pszValue, -1, CPLES_XML ); CPLAssert( psNode->psChild == NULL ); /* Escaped text might be bigger than expected. */ _GrowBuffer( strlen(pszEscaped) + *pnLength, ppszText, pnMaxLength ); strcat( *ppszText + *pnLength, pszEscaped ); CPLFree( pszEscaped ); } /* -------------------------------------------------------------------- */ /* Attributes require a little formatting. */ /* -------------------------------------------------------------------- */ else if( psNode->eType == CXT_Attribute ) { CPLAssert( psNode->psChild != NULL && psNode->psChild->eType == CXT_Text ); sprintf( *ppszText + *pnLength, " %s=\"", psNode->pszValue ); CPLSerializeXMLNode( psNode->psChild, 0, ppszText, pnLength, pnMaxLength ); strcat( *ppszText + *pnLength, "\"" ); } /* -------------------------------------------------------------------- */ /* Handle comment output. */ /* -------------------------------------------------------------------- */ else if( psNode->eType == CXT_Comment ) { int i; CPLAssert( psNode->psChild == NULL ); for( i = 0; i < nIndent; i++ ) (*ppszText)[(*pnLength)++] = ' '; sprintf( *ppszText + *pnLength, "\n", psNode->pszValue ); } /* -------------------------------------------------------------------- */ /* Handle literal output (like ) */ /* -------------------------------------------------------------------- */ else if( psNode->eType == CXT_Literal ) { int i; CPLAssert( psNode->psChild == NULL ); for( i = 0; i < nIndent; i++ ) (*ppszText)[(*pnLength)++] = ' '; strcpy( *ppszText + *pnLength, psNode->pszValue ); strcat( *ppszText + *pnLength, "\n" ); } /* -------------------------------------------------------------------- */ /* Elements actually have to deal with general children, and */ /* various formatting issues. */ /* -------------------------------------------------------------------- */ else if( psNode->eType == CXT_Element ) { int bHasNonAttributeChildren = FALSE; CPLXMLNode *psChild; memset( *ppszText + *pnLength, ' ', nIndent ); *pnLength += nIndent; (*ppszText)[*pnLength] = '\0'; sprintf( *ppszText + *pnLength, "<%s", psNode->pszValue ); /* Serialize *all* the attribute children, regardless of order */ for( psChild = psNode->psChild; psChild != NULL; psChild = psChild->psNext ) { if( psChild->eType == CXT_Attribute ) CPLSerializeXMLNode( psChild, 0, ppszText, pnLength, pnMaxLength ); else bHasNonAttributeChildren = TRUE; } if( !bHasNonAttributeChildren ) { if( psNode->pszValue[0] == '?' ) strcat( *ppszText + *pnLength, "?>\n" ); else strcat( *ppszText + *pnLength, "/>\n" ); } else { int bJustText = TRUE; strcat( *ppszText + *pnLength, ">" ); for( psChild = psNode->psChild; psChild != NULL; psChild = psChild->psNext ) { if( psChild->eType == CXT_Attribute ) continue; if( psChild->eType != CXT_Text && bJustText ) { bJustText = FALSE; strcat( *ppszText + *pnLength, "\n" ); } CPLSerializeXMLNode( psChild, nIndent + 2, ppszText, pnLength, pnMaxLength ); } *pnLength += strlen(*ppszText + *pnLength); _GrowBuffer( strlen(psNode->pszValue) + *pnLength + 40 + nIndent, ppszText, pnMaxLength ); if( !bJustText ) { memset( *ppszText + *pnLength, ' ', nIndent ); *pnLength += nIndent; (*ppszText)[*pnLength] = '\0'; } *pnLength += strlen(*ppszText + *pnLength); sprintf( *ppszText + *pnLength, "\n", psNode->pszValue ); } } } /************************************************************************/ /* CPLSerializeXMLTree() */ /************************************************************************/ /** * Convert tree into string document. * * This function converts a CPLXMLNode tree representation of a document * into a flat string representation. White space indentation is used * visually preserve the tree structure of the document. The returned * document becomes owned by the caller and should be freed with CPLFree() * when no longer needed. * * @param psNode * * @return the document on success or NULL on failure. */ char *CPLSerializeXMLTree( CPLXMLNode *psNode ) { unsigned int nMaxLength = 100, nLength = 0; char *pszText = NULL; CPLXMLNode *psThis; pszText = (char *) CPLMalloc(nMaxLength); pszText[0] = '\0'; for( psThis = psNode; psThis != NULL; psThis = psThis->psNext ) CPLSerializeXMLNode( psThis, 0, &pszText, &nLength, &nMaxLength ); return pszText; } /************************************************************************/ /* CPLCreateXMLNode() */ /************************************************************************/ /** * Create an document tree item. * * Create a single CPLXMLNode object with the desired value and type, and * attach it as a child of the indicated parent. * * @param poParent the parent to which this node should be attached as a * child. May be NULL to keep as free standing. * * @return the newly created node, now owned by the caller (or parent node). */ CPLXMLNode *CPLCreateXMLNode( CPLXMLNode *poParent, CPLXMLNodeType eType, const char *pszText ) { CPLXMLNode *psNode; /* -------------------------------------------------------------------- */ /* Create new node. */ /* -------------------------------------------------------------------- */ psNode = (CPLXMLNode *) CPLCalloc(sizeof(CPLXMLNode),1); psNode->eType = eType; psNode->pszValue = CPLStrdup( pszText ); /* -------------------------------------------------------------------- */ /* Attach to parent, if provided. */ /* -------------------------------------------------------------------- */ if( poParent != NULL ) { if( poParent->psChild == NULL ) poParent->psChild = psNode; else { CPLXMLNode *psLink = poParent->psChild; while( psLink->psNext != NULL ) psLink = psLink->psNext; psLink->psNext = psNode; } } return psNode; } /************************************************************************/ /* CPLDestroyXMLNode() */ /************************************************************************/ /** * Destroy a tree. * * This function frees resources associated with a CPLXMLNode and all its * children nodes. * * @param psNode the tree to free. */ void CPLDestroyXMLNode( CPLXMLNode *psNode ) { if( psNode == NULL ) return; if( psNode->psChild != NULL ) CPLDestroyXMLNode( psNode->psChild ); if( psNode->psNext != NULL ) CPLDestroyXMLNode( psNode->psNext ); CPLFree( psNode->pszValue ); CPLFree( psNode ); } /************************************************************************/ /* CPLSearchXMLNode() */ /************************************************************************/ /** * Search for a node in document. * * Searches the children (and potentially siblings) of the documented * passed in for the named element or attribute. To search following * siblings as well as children, prefix the pszElement name with an equal * sign. This function does an in-order traversal of the document tree. * So it will first match against the current node, then it's first child, * that childs first child, and so on. * * Use CPLGetXMLNode() to find a specific child, or along a specific * node path. * * @param psRoot the subtree to search. This should be a node of type * CXT_Element. NULL is safe. * * @param pszElement the name of the element or attribute to search for. * * @return The matching node or NULL on failure. */ CPLXMLNode *CPLSearchXMLNode( CPLXMLNode *psRoot, const char *pszElement ) { int bSideSearch = FALSE; CPLXMLNode *psChild, *psResult; if( psRoot == NULL || pszElement == NULL ) return NULL; if( *pszElement == '=' ) { bSideSearch = TRUE; pszElement++; } /* -------------------------------------------------------------------- */ /* Does this node match? */ /* -------------------------------------------------------------------- */ if( (psRoot->eType == CXT_Element || psRoot->eType == CXT_Attribute) && EQUAL(pszElement,psRoot->pszValue) ) return psRoot; /* -------------------------------------------------------------------- */ /* Search children. */ /* -------------------------------------------------------------------- */ for( psChild = psRoot->psChild; psChild != NULL; psChild = psChild->psNext) { if( (psChild->eType == CXT_Element || psChild->eType == CXT_Attribute) && EQUAL(pszElement,psChild->pszValue) ) return psChild; if( psChild->psChild != NULL ) { psResult = CPLSearchXMLNode( psChild, pszElement ); if( psResult != NULL ) return psResult; } } /* -------------------------------------------------------------------- */ /* Search siblings if we are in side search mode. */ /* -------------------------------------------------------------------- */ if( bSideSearch ) { for( psRoot = psRoot->psNext; psRoot != NULL; psRoot = psRoot->psNext ) { psResult = CPLSearchXMLNode( psRoot, pszElement ); if( psResult != NULL ) return psResult; } } return NULL; } /************************************************************************/ /* CPLGetXMLNode() */ /************************************************************************/ /** * Find node by path. * * Searches the document or subdocument indicated by psRoot for an element * (or attribute) with the given path. The path should consist of a set of * element names separated by dots, not including the name of the root * element (psRoot). If the requested element is not found NULL is returned. * * Attribute names may only appear as the last item in the path. * * The search is done from the root nodes children, but all intermediate * nodes in the path must be specified. Seaching for "name" would only find * a name element or attribute if it is a direct child of the root, not at any * level in the subdocument. * * If the pszPath is prefixed by "=" then the search will begin with the * root node, and it's siblings, instead of the root nodes children. This * is particularly useful when searching within a whole document which is * often prefixed by one or more "junk" nodes like the declaration. * * @param psRoot the subtree in which to search. This should be a node of * type CXT_Element. NULL is safe. * * @param pszPath the list of element names in the path (dot separated). * * @return the requested element node, or NULL if not found. */ CPLXMLNode *CPLGetXMLNode( CPLXMLNode *psRoot, const char *pszPath ) { char **papszTokens; int iToken = 0; int bSideSearch = FALSE; if( psRoot == NULL ) return NULL; if( *pszPath == '=' ) { bSideSearch = TRUE; pszPath++; } papszTokens = CSLTokenizeStringComplex( pszPath, ".", FALSE, FALSE ); while( papszTokens[iToken] != NULL && psRoot != NULL ) { CPLXMLNode *psChild; if( bSideSearch ) { psChild = psRoot; bSideSearch = FALSE; } else psChild = psRoot->psChild; for( ; psChild != NULL; psChild = psChild->psNext ) { if( psChild->eType != CXT_Text && EQUAL(papszTokens[iToken],psChild->pszValue) ) break; } if( psChild == NULL ) { psRoot = NULL; break; } psRoot = psChild; iToken++; } CSLDestroy( papszTokens ); return psRoot; } /************************************************************************/ /* CPLGetXMLValue() */ /************************************************************************/ /** * Fetch element/attribute value. * * Searches the document for the element/attribute value associated with * the path. The corresponding node is internally found with CPLGetXMLNode() * (see there for details on path handling). Once found, the value is * considered to be the first CXT_Text child of the node. * * If the attribute/element search fails, or if the found node has not * value then the passed default value is returned. * * The returned value points to memory within the document tree, and should * not be altered or freed. * * @param psRoot the subtree in which to search. This should be a node of * type CXT_Element. NULL is safe. * * @param pszPath the list of element names in the path (dot separated). An * empty path means get the value of the psRoot node. * * @param pszDefault the value to return if a corresponding value is not * found, may be NULL. * * @return the requested value or pszDefault if not found. */ const char *CPLGetXMLValue( CPLXMLNode *psRoot, const char *pszPath, const char *pszDefault ) { CPLXMLNode *psTarget; if( pszPath == NULL || *pszPath == '\0' ) psTarget = psRoot; else psTarget = CPLGetXMLNode( psRoot, pszPath ); if( psTarget == NULL ) return pszDefault; if( psTarget->eType == CXT_Attribute ) { CPLAssert( psTarget->psChild != NULL && psTarget->psChild->eType == CXT_Text ); return psTarget->psChild->pszValue; } if( psTarget->eType == CXT_Element ) { // Find first non-attribute child, and verify it is a single text // with no siblings psTarget = psTarget->psChild; while( psTarget != NULL && psTarget->eType == CXT_Attribute ) psTarget = psTarget->psNext; if( psTarget != NULL && psTarget->eType == CXT_Text && psTarget->psNext == NULL ) return psTarget->pszValue; } return pszDefault; } /************************************************************************/ /* CPLAddXMLChild() */ /************************************************************************/ /** * Add child node to parent. * * The passed child is added to the list of children of the indicated * parent. Normally the child is added at the end of the parents child * list, but attributes (CXT_Attribute) will be inserted after any other * attributes but before any other element type. Ownership of the child * node is effectively assumed by the parent node. If the child has * siblings (it's psNext is not NULL) they will be trimmed, but if the child * has children they are carried with it. * * @param psParent the node to attach the child to. May not be NULL. * * @param psChild the child to add to the parent. May not be NULL. Should * not be a child of any other parent. */ void CPLAddXMLChild( CPLXMLNode *psParent, CPLXMLNode *psChild ) { CPLXMLNode *psSib; CPLAssert( psChild->psNext == NULL ); psChild->psNext = NULL; if( psParent->psChild == NULL ) { psParent->psChild = psChild; return; } // Insert at head of list if first child is not attribute. if( psChild->eType == CXT_Attribute && psParent->psChild->eType != CXT_Attribute ) { psChild->psNext = psParent->psChild; psParent->psChild = psChild; return; } // Search for end of list. for( psSib = psParent->psChild; psSib->psNext != NULL; psSib = psSib->psNext ) { // Insert attributes if the next node is not an attribute. if( psChild->eType == CXT_Attribute && psSib->psNext != NULL && psSib->psNext->eType != CXT_Attribute ) { psChild->psNext = psSib->psNext; psSib->psNext = psChild; return; } } psSib->psNext = psChild; } /************************************************************************/ /* CPLAddXMLSibling() */ /************************************************************************/ /** * Add new sibling. * * The passed psNewSibling is added to the end of siblings of the * psOlderSibling node. That is, it is added to the end of the psNext * chain. There is no special handling if psNewSibling is an attribute. * If this is required, use CPLAddXMLChild(). * * @param psOlderSibling the node to attach the sibling after. * * @param psNewSibling the node to add at the end of psOlderSiblings psNext * chain. */ void CPLAddXMLSibling( CPLXMLNode *psOlderSibling, CPLXMLNode *psNewSibling ) { if( psOlderSibling == NULL ) return; while( psOlderSibling->psNext != NULL ) psOlderSibling = psOlderSibling->psNext; psOlderSibling->psNext = psNewSibling; } /************************************************************************/ /* CPLCreateXMLElementAndValue() */ /************************************************************************/ /** * Create an element and text value. * * This is function is a convenient short form for: * * CPLXMLNode *psTextNode; * CPLXMLNode *psElementNode; * * psElementNode = CPLCreateXMLNode( psParent, CXT_Element, pszName ); * psTextNode = CPLCreateXMLNode( psElementNode, CXT_Text, pszValue ); * * return psElementNode; * * It creates a CXT_Element node, with a CXT_Text child, and * attaches the element to the passed parent. * * @param psParent the parent node to which the resulting node should * be attached. May be NULL to keep as freestanding. * * @param pszName the element name to create. * @param pszValue the text to attach to the element. Must not be NULL. * * @return the pointer to the new element node. */ CPLXMLNode *CPLCreateXMLElementAndValue( CPLXMLNode *psParent, const char *pszName, const char *pszValue ) { CPLXMLNode *psTextNode; CPLXMLNode *psElementNode; psElementNode = CPLCreateXMLNode( psParent, CXT_Element, pszName ); psTextNode = CPLCreateXMLNode( psElementNode, CXT_Text, pszValue ); return psElementNode; } /************************************************************************/ /* CPLCloneXMLTree() */ /************************************************************************/ /** * Copy tree. * * Creates a deep copy of a CPLXMLNode tree. * * @param psTree the tree to duplicate. * * @return a copy of the whole tree. */ CPLXMLNode *CPLCloneXMLTree( CPLXMLNode *psTree ) { CPLXMLNode *psPrevious = NULL; CPLXMLNode *psReturn = NULL; while( psTree != NULL ) { CPLXMLNode *psCopy; psCopy = CPLCreateXMLNode( NULL, psTree->eType, psTree->pszValue ); if( psReturn == NULL ) psReturn = psCopy; if( psPrevious != NULL ) psPrevious->psNext = psCopy; if( psTree->psChild != NULL ) psCopy->psChild = CPLCloneXMLTree( psTree->psChild ); psPrevious = psCopy; psTree = psTree->psNext; } return psReturn; } /************************************************************************/ /* CPLSetXMLValue() */ /************************************************************************/ /** * Set element value by path. * * Find (or create) the target element or attribute specified in the * path, and assign it the indicated value. * * Any path elements that do not already exist will be created. The target * nodes value (the first CXT_Text child) will be replaced with the provided * value. * * If the target node is an attribute instead of an element, the last separator * should be a "#" instead of the normal period path separator. * * Example: * CPLSetXMLValue( "Citation.Id.Description", "DOQ dataset" ); * CPLSetXMLValue( "Citation.Id.Description#name", "doq" ); * * @param psRoot the subdocument to be updated. * * @param pszPath the dot seperated path to the target element/attribute. * * @param pszValue the text value to assign. * * @return TRUE on success. */ int CPLSetXMLValue( CPLXMLNode *psRoot, const char *pszPath, const char *pszValue ) { char **papszTokens; int iToken = 0; papszTokens = CSLTokenizeStringComplex( pszPath, ".", FALSE, FALSE ); while( papszTokens[iToken] != NULL && psRoot != NULL ) { CPLXMLNode *psChild; int bIsAttribute = FALSE; const char *pszName = papszTokens[iToken]; if( pszName[0] == '#' ) { bIsAttribute = TRUE; pszName++; } if( psRoot->eType != CXT_Element ) return FALSE; for( psChild = psRoot->psChild; psChild != NULL; psChild = psChild->psNext ) { if( psChild->eType != CXT_Text && EQUAL(pszName,psChild->pszValue) ) break; } if( psChild == NULL ) { if( bIsAttribute ) psChild = CPLCreateXMLNode( psRoot, CXT_Attribute, pszName ); else psChild = CPLCreateXMLNode( psRoot, CXT_Element, pszName ); } psRoot = psChild; iToken++; } CSLDestroy( papszTokens ); /* -------------------------------------------------------------------- */ /* Find the "text" child if there is one. */ /* -------------------------------------------------------------------- */ CPLXMLNode *psTextChild = psRoot->psChild; while( psTextChild != NULL && psTextChild->eType != CXT_Text ) psTextChild = psTextChild->psNext; /* -------------------------------------------------------------------- */ /* Now set a value node under this node. */ /* -------------------------------------------------------------------- */ if( psTextChild == NULL ) CPLCreateXMLNode( psRoot, CXT_Text, pszValue ); else { CPLFree( psTextChild->pszValue ); psTextChild->pszValue = CPLStrdup( pszValue ); } return TRUE; } /************************************************************************/ /* CPLStripXMLNamespace() */ /************************************************************************/ /** * Strip indicated namespaces. * * The subdocument (psRoot) is recursively examined, and any elements * with the indicated namespace prefix will have the namespace prefix * stripped from the element names. If the passed namespace is NULL, then * all namespace prefixes will be stripped. * * Nodes other than elements should remain unaffected. The changes are * made "in place", and should not alter any node locations, only the * pszValue field of affected nodes. * * @param psRoot the document to operate on. * @param pszNamespace the name space prefix (not including colon), or NULL. * @param bRecurse TRUE to recurse over whole document, or FALSE to only * operate on the passed node. */ void CPLStripXMLNamespace( CPLXMLNode *psRoot, const char *pszNamespace, int bRecurse ) { if( psRoot == NULL ) return; if( psRoot->eType == CXT_Element || psRoot->eType == CXT_Attribute ) { if( pszNamespace != NULL ) { if( EQUALN(pszNamespace,psRoot->pszValue,strlen(pszNamespace)) && psRoot->pszValue[strlen(pszNamespace)] == ':' ) { char *pszNewValue = CPLStrdup(psRoot->pszValue+strlen(pszNamespace)+1); CPLFree( psRoot->pszValue ); psRoot->pszValue = pszNewValue; } } else { const char *pszCheck; for( pszCheck = psRoot->pszValue; *pszCheck != '\0'; pszCheck++ ) { if( *pszCheck == ':' ) { char *pszNewValue = CPLStrdup( pszCheck+1 ); CPLFree( psRoot->pszValue ); psRoot->pszValue = pszNewValue; break; } } } } if( bRecurse ) { if( psRoot->psChild != NULL ) CPLStripXMLNamespace( psRoot->psChild, pszNamespace, 1 ); if( psRoot->psNext != NULL ) CPLStripXMLNamespace( psRoot->psNext, pszNamespace, 1 ); } } /************************************************************************/ /* CPLParseXMLFile() */ /************************************************************************/ /** * Parse XML file into tree. * * The named file is opened, loaded into memory as a big string, and * parsed with CPLParseXMLString(). Errors in reading the file or parsing * the XML will be reported by CPLError(). * * @param pszFilename the file to open. * * @return NULL on failure, or the document tree on success. */ CPLXMLNode *CPLParseXMLFile( const char *pszFilename ) { FILE *fp; int nLen; char *pszDoc; CPLXMLNode *psTree; /* -------------------------------------------------------------------- */ /* Read the file. */ /* -------------------------------------------------------------------- */ fp = VSIFOpen( pszFilename, "rb" ); if( fp == NULL ) { CPLError( CE_Failure, CPLE_OpenFailed, "Failed to open %.500s to read.", pszFilename ); return NULL; } VSIFSeek( fp, 0, SEEK_END ); nLen = VSIFTell( fp ); VSIFSeek( fp, 0, SEEK_SET ); pszDoc = (char *) VSIMalloc(nLen+1); if( pszDoc == NULL ) { CPLError( CE_Failure, CPLE_OutOfMemory, "Out of memory allocating space for %d byte buffer in\n" "CPLParseXMLFile(%.500s).", nLen+1, pszFilename ); VSIFClose( fp ); return NULL; } if( (int) VSIFRead( pszDoc, 1, nLen, fp ) < nLen ) { CPLError( CE_Failure, CPLE_FileIO, "VSIFRead() result short of expected %d bytes from %.500s.", nLen, pszFilename ); pszDoc[0] = '\0'; } VSIFClose( fp ); pszDoc[nLen] = '\0'; /* -------------------------------------------------------------------- */ /* Parse it. */ /* -------------------------------------------------------------------- */ psTree = CPLParseXMLString( pszDoc ); CPLFree( pszDoc ); return psTree; } /************************************************************************/ /* CPLSerializeXMLTreeToFile() */ /************************************************************************/ /** * Write document tree to a file. * * The passed document tree is converted into one big string (with * CPLSerializeXMLTree()) and then written to the named file. Errors writing * the file will be reported by CPLError(). The source document tree is * not altered. If the output file already exists it will be overwritten. * * @param psTree the document tree to write. * @param pszFilename the name of the file to write to. */ int CPLSerializeXMLTreeToFile( CPLXMLNode *psTree, const char *pszFilename ) { char *pszDoc; FILE *fp; int nLength; /* -------------------------------------------------------------------- */ /* Serialize document. */ /* -------------------------------------------------------------------- */ pszDoc = CPLSerializeXMLTree( psTree ); if( pszDoc == NULL ) return FALSE; nLength = strlen(pszDoc); /* -------------------------------------------------------------------- */ /* Create file. */ /* -------------------------------------------------------------------- */ fp = VSIFOpen( pszFilename, "wt" ); if( fp == NULL ) { CPLError( CE_Failure, CPLE_OpenFailed, "Failed to open %.500s to write.", pszFilename ); return FALSE; } /* -------------------------------------------------------------------- */ /* Write file. */ /* -------------------------------------------------------------------- */ if( (int) VSIFWrite( pszDoc, 1, nLength, fp ) != nLength ) { CPLError( CE_Failure, CPLE_FileIO, "Failed to write whole XML document (%.500s).", pszFilename ); VSIFClose( fp ); CPLFree( pszDoc ); return FALSE; } /* -------------------------------------------------------------------- */ /* Cleanup */ /* -------------------------------------------------------------------- */ VSIFClose( fp ); CPLFree( pszDoc ); return TRUE; } /************************************************************************/ /* CPLCleanXMLElementName() */ /************************************************************************/ /** * Make string into safe XML token. * * Modififies a string in place to try and make it into a legal * XML token that can be used as an element name. This is accomplished * by changing any characters not legal in a token into an underscore. * * NOTE: This function should implement the rules in section 2.3 of * http://www.w3.org/TR/xml11/ but it doesn't yet do that properly. We * only do a rough approximation of that. * * @param pszTarget the string to be adjusted. It is altered in place. */ void CPL_DLL CPLCleanXMLElementName( char *pszTarget ) { if( pszTarget == NULL ) return; for( ; *pszTarget != '\0'; pszTarget++ ) { if( (*((unsigned char *) pszTarget) & 0x80) || isalnum( *pszTarget ) || *pszTarget == '_' || *pszTarget == '.' ) { /* ok */ } else { *pszTarget = '_'; } } }