c14n.c.svn-base

这是一个用于解析xml文件的类库。使用这个类库

        }
        xmlOutputBufferWriteString(ctx->buf, (const char *) cur->name);
        xmlOutputBufferWriteString(ctx->buf, ">");
        if (parent_is_doc) {
	    /* restore this flag from the stack for next node */
            ctx->parent_is_doc = parent_is_doc;
	    ctx->pos = XMLC14N_AFTER_DOCUMENT_ELEMENT;
        }
    }

    /* 
     * Restore ns_rendered stack position
     */
    xmlC14NVisibleNsStackRestore(ctx->ns_rendered, &state);
    return (0);
}

/**
 * xmlC14NProcessNode:
 * @ctx: 		the pointer to C14N context object
 * @cur:		the node to process
 *  		
 * Processes the given node
 *
 * Returns non-negative value on success or negative value on fail
 */
static int
xmlC14NProcessNode(xmlC14NCtxPtr ctx, xmlNodePtr cur)
{
    int ret = 0;
    int visible;

    if ((ctx == NULL) || (cur == NULL)) {
#ifdef DEBUG_C14N
        xmlGenericError(xmlGenericErrorContext,
                        "xmlC14NProcessNode: Null context or node pointer.\n");
#endif
        return (-1);
    }

    visible = xmlC14NIsVisible(ctx, cur, cur->parent);
    switch (cur->type) {
        case XML_ELEMENT_NODE:
            ret = xmlC14NProcessElementNode(ctx, cur, visible);
            break;
        case XML_CDATA_SECTION_NODE:
        case XML_TEXT_NODE:
            /*
             * Text Nodes
             * the string value, except all ampersands are replaced 
             * by &amp;, all open angle brackets (<) are replaced by &lt;, all closing 
             * angle brackets (>) are replaced by &gt;, and all #xD characters are 
             * replaced by &#xD;.
             */
            /* cdata sections are processed as text nodes */
            /* todo: verify that cdata sections are included in XPath nodes set */
            if ((visible) && (cur->content != NULL)) {
                xmlChar *buffer;

                buffer = xmlC11NNormalizeText(cur->content);
                if (buffer != NULL) {
                    xmlOutputBufferWriteString(ctx->buf,
                                               (const char *) buffer);
                    xmlFree(buffer);
                } else {
#ifdef DEBUG_C14N
                    xmlGenericError(xmlGenericErrorContext,
                                    "xmlC14NProcessNode: xmlC11NNormalizeText() failed\n");
#endif
                    return (-1);
                }
            }
            break;
        case XML_PI_NODE:
            /* 
             * Processing Instruction (PI) Nodes- 
             * The opening PI symbol (<?), the PI target name of the node, 
             * a leading space and the string value if it is not empty, and 
             * the closing PI symbol (?>). If the string value is empty, 
             * then the leading space is not added. Also, a trailing #xA is 
             * rendered after the closing PI symbol for PI children of the 
             * root node with a lesser document order than the document 
             * element, and a leading #xA is rendered before the opening PI 
             * symbol of PI children of the root node with a greater document 
             * order than the document element.
             */
            if (visible) {
                if (ctx->pos == XMLC14N_AFTER_DOCUMENT_ELEMENT) {
                    xmlOutputBufferWriteString(ctx->buf, "\x0A<?");
                } else {
                    xmlOutputBufferWriteString(ctx->buf, "<?");
                }

                xmlOutputBufferWriteString(ctx->buf,
                                           (const char *) cur->name);
                if ((cur->content != NULL) && (*(cur->content) != '\0')) {
                    xmlChar *buffer;

                    xmlOutputBufferWriteString(ctx->buf, " ");

                    /* todo: do we need to normalize pi? */
                    buffer = xmlC11NNormalizePI(cur->content);
                    if (buffer != NULL) {
                        xmlOutputBufferWriteString(ctx->buf,
                                                   (const char *) buffer);
                        xmlFree(buffer);
                    } else {
#ifdef DEBUG_C14N
                        xmlGenericError(xmlGenericErrorContext,
                                        "xmlC14NProcessNode: xmlC11NNormalizePI() failed\n");
#endif
                        return (-1);
                    }
                }

                if (ctx->pos == XMLC14N_BEFORE_DOCUMENT_ELEMENT) {
                    xmlOutputBufferWriteString(ctx->buf, "?>\x0A");
                } else {
                    xmlOutputBufferWriteString(ctx->buf, "?>");
                }
            }
            break;
        case XML_COMMENT_NODE:
            /*
             * Comment Nodes
             * Nothing if generating canonical XML without  comments. For 
             * canonical XML with comments, generate the opening comment 
             * symbol (<!--), the string value of the node, and the 
             * closing comment symbol (-->). Also, a trailing #xA is rendered 
             * after the closing comment symbol for comment children of the 
             * root node with a lesser document order than the document 
             * element, and a leading #xA is rendered before the opening 
             * comment symbol of comment children of the root node with a 
             * greater document order than the document element. (Comment 
             * children of the root node represent comments outside of the 
             * top-level document element and outside of the document type 
             * declaration).
             */
            if (visible && ctx->with_comments) {
                if (ctx->pos == XMLC14N_AFTER_DOCUMENT_ELEMENT) {
                    xmlOutputBufferWriteString(ctx->buf, "\x0A<!--");
                } else {
                    xmlOutputBufferWriteString(ctx->buf, "<!--");
                }

                if (cur->content != NULL) {
                    xmlChar *buffer;

                    /* todo: do we need to normalize comment? */
                    buffer = xmlC11NNormalizeComment(cur->content);
                    if (buffer != NULL) {
                        xmlOutputBufferWriteString(ctx->buf,
                                                   (const char *) buffer);
                        xmlFree(buffer);
                    } else {
#ifdef DEBUG_C14N
                        xmlGenericError(xmlGenericErrorContext,
                                        "xmlC14NProcessNode: xmlC11NNormalizeComment() failed\n");
#endif
                        return (-1);
                    }
                }

                if (ctx->pos == XMLC14N_BEFORE_DOCUMENT_ELEMENT) {
                    xmlOutputBufferWriteString(ctx->buf, "-->\x0A");
                } else {
                    xmlOutputBufferWriteString(ctx->buf, "-->");
                }
            }
            break;
        case XML_DOCUMENT_NODE:
        case XML_DOCUMENT_FRAG_NODE:   /* should be processed as document? */
#ifdef LIBXML_DOCB_ENABLED
        case XML_DOCB_DOCUMENT_NODE:   /* should be processed as document? */
#endif
#ifdef LIBXML_HTML_ENABLED
        case XML_HTML_DOCUMENT_NODE:   /* should be processed as document? */
#endif
            if (cur->children != NULL) {
                ctx->pos = XMLC14N_BEFORE_DOCUMENT_ELEMENT;
                ctx->parent_is_doc = 1;
                ret = xmlC14NProcessNodeList(ctx, cur->children);
            }
            break;

        case XML_ATTRIBUTE_NODE:
	    xmlC14NErr(ctx, cur, XML_C14N_INVALID_NODE,
		"xmlC14NProcessNode: XML_ATTRIBUTE_NODE is illegal here\n");
            return (-1);
        case XML_NAMESPACE_DECL:
	    xmlC14NErr(ctx, cur, XML_C14N_INVALID_NODE,
		"xmlC14NProcessNode: XML_NAMESPACE_DECL is illegal here\n");
            return (-1);
        case XML_ENTITY_REF_NODE:
	    xmlC14NErr(ctx, cur, XML_C14N_INVALID_NODE,
		"xmlC14NProcessNode: XML_ENTITY_REF_NODE is illegal here\n");
            return (-1);
        case XML_ENTITY_NODE:
	    xmlC14NErr(ctx, cur, XML_C14N_INVALID_NODE,
		"xmlC14NProcessNode: XML_ENTITY_NODE is illegal here\n");
            return (-1);

        case XML_DOCUMENT_TYPE_NODE:
        case XML_NOTATION_NODE:
        case XML_DTD_NODE:
        case XML_ELEMENT_DECL:
        case XML_ATTRIBUTE_DECL:
        case XML_ENTITY_DECL:
#ifdef LIBXML_XINCLUDE_ENABLED
        case XML_XINCLUDE_START:
        case XML_XINCLUDE_END:
#endif
            /* 
             * should be ignored according to "W3C Canonical XML" 
             */
            break;
        default:
#ifdef DEBUG_C14N
            xmlGenericError(xmlGenericErrorContext,
                            "xmlC14NProcessNode: unknown node type = %d\n",
                            cur->type);
#endif
            return (-1);
    }

    return (ret);
}

/**
 * xmlC14NProcessNodeList:
 * @ctx: 		the pointer to C14N context object
 * @cur:		the node to start from
 *  		
 * Processes all nodes in the row starting from cur.
 *
 * Returns non-negative value on success or negative value on fail
 */
static int
xmlC14NProcessNodeList(xmlC14NCtxPtr ctx, xmlNodePtr cur)
{
    int ret;

    if (ctx == NULL) {
#ifdef DEBUG_C14N
        xmlGenericError(xmlGenericErrorContext,
                        "xmlC14NProcessNodeList: Null context pointer.\n");
#endif
        return (-1);
    }

    for (ret = 0; cur != NULL && ret >= 0; cur = cur->next) {
        ret = xmlC14NProcessNode(ctx, cur);
    }
    return (ret);
}


/**
 * xmlC14NFreeCtx:
 * @ctx: the pointer to C14N context object
 * 		
 * Cleanups the C14N context object.
 */

static void
xmlC14NFreeCtx(xmlC14NCtxPtr ctx)
{
    if (ctx == NULL) {
#ifdef DEBUG_C14N
        xmlGenericError(xmlGenericErrorContext,
                        "xmlC14NFreeCtx: ctx == NULL\n");
#endif
        return;
    }

    if (ctx->ns_rendered != NULL) {
        xmlC14NVisibleNsStackDestroy(ctx->ns_rendered);
    }
    xmlFree(ctx);
}

/**
 * xmlC14NNewCtx:
 * @doc: 		the XML document for canonization
 * @is_visible_callback:the function to use to determine is node visible 
 *			or not
 * @user_data: 		the first parameter for @is_visible_callback function
 *			(in most cases, it is nodes set)
 * @inclusive_ns_prefixe the list of inclusive namespace prefixes 
 *			ended with a NULL or NULL if there is no
 *			inclusive namespaces (only for exclusive 
 *			canonicalization)
 * @with_comments: 	include comments in the result (!=0) or not (==0)
 * @buf: 		the output buffer to store canonical XML; this 
 *			buffer MUST have encoder==NULL because C14N requires
 *			UTF-8 output
 *  		
 * Creates new C14N context object to store C14N parameters.
 *
 * Returns pointer to newly created object (success) or NULL (fail)
 */
static xmlC14NCtxPtr
xmlC14NNewCtx(xmlDocPtr doc,  
	      xmlC14NIsVisibleCallback is_visible_callback, void* user_data,
              int exclusive, xmlChar ** inclusive_ns_prefixes,
              int with_comments, xmlOutputBufferPtr buf)
{
    xmlC14NCtxPtr ctx = NULL;

    if ((doc == NULL) || (buf == NULL)) {
#ifdef DEBUG_C14N
        xmlGenericError(xmlGenericErrorContext,
                        "xmlC14NNewCtx: pointer to document or output buffer is NULL\n");
#endif
        return (NULL);
    }

    /*
     *  Validate the encoding output buffer encoding
     */
    if (buf->encoder != NULL) {
        xmlC14NErr(ctx, (xmlNodePtr) doc, XML_C14N_REQUIRES_UTF8,
"xmlC14NNewCtx: output buffer encoder != NULL but C14N requires UTF8 output\n");
        return (NULL);
    }

    /*
     *  Validate the XML document encoding value, if provided.
     */
    if (doc->charset != XML_CHAR_ENCODING_UTF8) {
        xmlC14NErr(ctx, (xmlNodePtr) doc, XML_C14N_REQUIRES_UTF8,
		   "xmlC14NNewCtx: source document not in UTF8\n");
        return (NULL);
    }

    /*
     * Allocate a new xmlC14NCtxPtr and fill the fields.
     */
    ctx = (xmlC14NCtxPtr) xmlMalloc(sizeof(xmlC14NCtx));
    if (ctx == NULL) {
	xmlC14NErrMemory("creating context");
        return (NULL);
    }
    memset(ctx, 0, sizeof(xmlC14NCtx));

    /*
     * initialize C14N context
     */
    ctx->doc = doc;
    ctx->with_comments = with_comments;
    ctx->is_visible_callback = is_visible_callback;
    ctx->user_data = user_data;
    ctx->buf = buf;
    ctx->parent_is_doc = 1;
    ctx->pos = XMLC14N_BEFORE_DOCUMENT_ELEMENT;
    ctx->ns_rendered = xmlC14NVisibleNsStackCreate();

    if(ctx->ns_rendered == NULL) {
        xmlC14NErr(ctx, (xmlNodePtr) doc, XML_C14N_CREATE_STACK,
		   "xmlC14NNewCtx: xmlC14NVisibleNsStackCreate failed\n");
	xmlC14NFreeCtx(ctx);
        return (NULL);
    }

    /*
     * Set "exclusive" flag, create a nodes set for namespaces
     * stack and remember list of incluseve prefixes
     */
    if (exclusive) {
        ctx->exclusive = 1;
        ctx->inclusive_ns_prefixes = inclusive_ns_prefixes;
    }
    return (ctx);
}

/**
 * xmlC14NExecute:
 * @doc: 		the XML document for canonization
 * @is_visible_callback:the function to use to determine is node visible 
 *			or not
 * @user_data: 		the first parameter for @is_visible_callback function
 *			(in most cases, it is nodes set)
 * @exclusive:		the exclusive flag (0 - non-exclusive canonicalization;
 *			otherwise - exclusive canonicalization)
 * @inclusive_ns_prefixes: the list of inclusive namespace prefixes 
 *			ended with a NULL or NULL if there is no
 *			inclusive namespaces (only for exclusive 
 *			canonicalization, ignored otherwise)
 * @with_comments: 	include comments in the result (!=0) or not (==0)
 * @buf: 		the output buffer to store canonical XML; this 
 *			buffer MUST have encoder==NULL because C14N requires
 *			UTF-8 output
 *  		
 * Dumps the canonized image of given XML document into the provided buffer.
 * For details see "Canonical XML" (http://www.w3.org/TR/xml-c14n) or
 * "Exclusive XML Canonicalization" (http://www.w3.org/TR/xml-exc-c14n)
 *