catalog.c

ReactOS是一些高手根据Windows XP的内核编写出的类XP。内核实现机理和API函数调用几乎相同。甚至可以兼容XP的程序。喜欢研究系统内核的人可以看一看。

	return(0);
    }

    if (xmlCatalogXMLFiles != NULL) {
	doc = (xmlCatalogEntryPtr)
	    xmlHashLookup(xmlCatalogXMLFiles, catal->URL);
	if (doc != NULL) {
	    if (xmlDebugCatalogs)
		xmlGenericError(xmlGenericErrorContext,
		    "Found %s in file hash\n", catal->URL);

	    if (catal->type == XML_CATA_CATALOG)
		catal->children = doc->children;
	    else
		catal->children = doc;
	    catal->dealloc = 0;
	    xmlRMutexUnlock(xmlCatalogMutex);
	    return(0);
	}
	if (xmlDebugCatalogs)
	    xmlGenericError(xmlGenericErrorContext,
		"%s not found in file hash\n", catal->URL);
    }

    /*
     * Fetch and parse. Note that xmlParseXMLCatalogFile does not
     * use the existing catalog, there is no recursion allowed at
     * that level.
     */
    doc = xmlParseXMLCatalogFile(catal->prefer, catal->URL);
    if (doc == NULL) {
	catal->type = XML_CATA_BROKEN_CATALOG;
	xmlRMutexUnlock(xmlCatalogMutex);
	return(-1);
    }

    if (catal->type == XML_CATA_CATALOG)
	catal->children = doc->children;
    else
	catal->children = doc;

    doc->dealloc = 1;

    if (xmlCatalogXMLFiles == NULL)
	xmlCatalogXMLFiles = xmlHashCreate(10);
    if (xmlCatalogXMLFiles != NULL) {
	if (xmlDebugCatalogs)
	    xmlGenericError(xmlGenericErrorContext,
		"%s added to file hash\n", catal->URL);
	xmlHashAddEntry(xmlCatalogXMLFiles, catal->URL, doc);
    }
    xmlRMutexUnlock(xmlCatalogMutex);
    return(0);
}

/************************************************************************
 *									*
 *			XML Catalog handling				*
 *									*
 ************************************************************************/

/**
 * xmlAddXMLCatalog:
 * @catal:  top of an XML catalog
 * @type:  the type of record to add to the catalog
 * @orig:  the system, public or prefix to match (or NULL)
 * @replace:  the replacement value for the match
 *
 * Add an entry in the XML catalog, it may overwrite existing but
 * different entries.
 *
 * Returns 0 if successful, -1 otherwise
 */
static int
xmlAddXMLCatalog(xmlCatalogEntryPtr catal, const xmlChar *type,
	      const xmlChar *orig, const xmlChar *replace) {
    xmlCatalogEntryPtr cur;
    xmlCatalogEntryType typ;
    int doregister = 0;

    if ((catal == NULL) || 
	((catal->type != XML_CATA_CATALOG) &&
	 (catal->type != XML_CATA_BROKEN_CATALOG)))
	return(-1);
    if (catal->children == NULL) {
	xmlFetchXMLCatalogFile(catal);
    }
    if (catal->children == NULL)
	doregister = 1;

    typ = xmlGetXMLCatalogEntryType(type);
    if (typ == XML_CATA_NONE) {
	if (xmlDebugCatalogs)
	    xmlGenericError(xmlGenericErrorContext,
		    "Failed to add unknown element %s to catalog\n", type);
	return(-1);
    }

    cur = catal->children;
    /*
     * Might be a simple "update in place"
     */
    if (cur != NULL) {
	while (cur != NULL) {
	    if ((orig != NULL) && (cur->type == typ) &&
		(xmlStrEqual(orig, cur->name))) {
		if (xmlDebugCatalogs)
		    xmlGenericError(xmlGenericErrorContext,
			    "Updating element %s to catalog\n", type);
		if (cur->value != NULL)
		    xmlFree(cur->value);
		if (cur->URL != NULL)
		    xmlFree(cur->URL);
		cur->value = xmlStrdup(replace);
		cur->URL = xmlStrdup(replace);
		return(0);
	    }
	    if (cur->next == NULL)
		break;
	    cur = cur->next;
	}
    }
    if (xmlDebugCatalogs)
	xmlGenericError(xmlGenericErrorContext,
		"Adding element %s to catalog\n", type);
    if (cur == NULL)
	catal->children = xmlNewCatalogEntry(typ, orig, replace,
		                             NULL, catal->prefer, NULL);
    else
	cur->next = xmlNewCatalogEntry(typ, orig, replace,
		                       NULL, catal->prefer, NULL);
    if (doregister) {
	cur = xmlHashLookup(xmlCatalogXMLFiles, catal->URL);
	if (cur != NULL)
	    cur->children = catal->children;
    }

    return(0);
}

/**
 * xmlDelXMLCatalog:
 * @catal:  top of an XML catalog
 * @value:  the value to remove from the catalog
 *
 * Remove entries in the XML catalog where the value or the URI
 * is equal to @value
 *
 * Returns the number of entries removed if successful, -1 otherwise
 */
static int
xmlDelXMLCatalog(xmlCatalogEntryPtr catal, const xmlChar *value) {
    xmlCatalogEntryPtr cur;
    int ret = 0;

    if ((catal == NULL) || 
	((catal->type != XML_CATA_CATALOG) &&
	 (catal->type != XML_CATA_BROKEN_CATALOG)))
	return(-1);
    if (value == NULL)
	return(-1);
    if (catal->children == NULL) {
	xmlFetchXMLCatalogFile(catal);
    }

    /*
     * Scan the children
     */
    cur = catal->children;
    while (cur != NULL) {
	if (((cur->name != NULL) && (xmlStrEqual(value, cur->name))) ||
	    (xmlStrEqual(value, cur->value))) {
	    if (xmlDebugCatalogs) {
		if (cur->name != NULL)
		    xmlGenericError(xmlGenericErrorContext,
			    "Removing element %s from catalog\n", cur->name);
		else
		    xmlGenericError(xmlGenericErrorContext,
			    "Removing element %s from catalog\n", cur->value);
	    }
	    cur->type = XML_CATA_REMOVED;
	}
	cur = cur->next;
    }
    return(ret);
}

/**
 * xmlCatalogXMLResolve:
 * @catal:  a catalog list
 * @pubID:  the public ID string
 * @sysID:  the system ID string
 *
 * Do a complete resolution lookup of an External Identifier for a
 * list of catalog entries.
 *
 * Implements (or tries to) 7.1. External Identifier Resolution
 * from http://www.oasis-open.org/committees/entity/spec-2001-08-06.html
 *
 * Returns the URI of the resource or NULL if not found
 */
static xmlChar *
xmlCatalogXMLResolve(xmlCatalogEntryPtr catal, const xmlChar *pubID,
	              const xmlChar *sysID) {
    xmlChar *ret = NULL;
    xmlCatalogEntryPtr cur;
    int haveDelegate = 0;
    int haveNext = 0;

    /*
     * protection against loops
     */
    if (catal->depth > MAX_CATAL_DEPTH) {
	xmlCatalogErr(catal, NULL, XML_CATALOG_RECURSION,
		      "Detected recursion in catalog %s\n",
		      catal->name, NULL, NULL);
	return(NULL);
    }
    catal->depth++;

    /*
     * First tries steps 2/ 3/ 4/ if a system ID is provided.
     */
    if (sysID != NULL) {
	xmlCatalogEntryPtr rewrite = NULL;
	int lenrewrite = 0, len;
	cur = catal;
	haveDelegate = 0;
	while (cur != NULL) {
	    switch (cur->type) {
		case XML_CATA_SYSTEM:
		    if (xmlStrEqual(sysID, cur->name)) {
			if (xmlDebugCatalogs)
			    xmlGenericError(xmlGenericErrorContext,
				    "Found system match %s\n", cur->name);
			catal->depth--;
			return(xmlStrdup(cur->URL));
		    }
		    break;
		case XML_CATA_REWRITE_SYSTEM:
		    len = xmlStrlen(cur->name);
		    if ((len > lenrewrite) &&
			(!xmlStrncmp(sysID, cur->name, len))) {
			lenrewrite = len;
			rewrite = cur;
		    }
		    break;
		case XML_CATA_DELEGATE_SYSTEM:
		    if (!xmlStrncmp(sysID, cur->name, xmlStrlen(cur->name)))
			haveDelegate++;
		    break;
		case XML_CATA_NEXT_CATALOG:
		    haveNext++;
		    break;
		default:
		    break;
	    }
	    cur = cur->next;
	}
	if (rewrite != NULL) {
	    if (xmlDebugCatalogs)
		xmlGenericError(xmlGenericErrorContext,
			"Using rewriting rule %s\n", rewrite->name);
	    ret = xmlStrdup(rewrite->URL);
	    if (ret != NULL)
		ret = xmlStrcat(ret, &sysID[lenrewrite]);
	    catal->depth--;
	    return(ret);
	}
	if (haveDelegate) {
	    const xmlChar *delegates[MAX_DELEGATE];
	    int nbList = 0, i;

	    /*
	     * Assume the entries have been sorted by decreasing substring
	     * matches when the list was produced.
	     */
	    cur = catal;
	    while (cur != NULL) {
		if ((cur->type == XML_CATA_DELEGATE_SYSTEM) &&
		    (!xmlStrncmp(sysID, cur->name, xmlStrlen(cur->name)))) {
		    for (i = 0;i < nbList;i++)
			if (xmlStrEqual(cur->URL, delegates[i]))
			    break;
		    if (i < nbList) {
			cur = cur->next;
			continue;
		    }
		    if (nbList < MAX_DELEGATE)
			delegates[nbList++] = cur->URL;

		    if (cur->children == NULL) {
			xmlFetchXMLCatalogFile(cur);
		    }
		    if (cur->children != NULL) {
			if (xmlDebugCatalogs)
			    xmlGenericError(xmlGenericErrorContext,
				    "Trying system delegate %s\n", cur->URL);
			ret = xmlCatalogListXMLResolve(
				cur->children, NULL, sysID);
			if (ret != NULL) {
			    catal->depth--;
			    return(ret);
			}
		    }
		}
		cur = cur->next;
	    }
	    /*
	     * Apply the cut algorithm explained in 4/
	     */
	    catal->depth--;
	    return(XML_CATAL_BREAK);
	}
    }
    /*
     * Then tries 5/ 6/ if a public ID is provided
     */
    if (pubID != NULL) {
	cur = catal;
	haveDelegate = 0;
	while (cur != NULL) {
	    switch (cur->type) {
		case XML_CATA_PUBLIC:
		    if (xmlStrEqual(pubID, cur->name)) {
			if (xmlDebugCatalogs)
			    xmlGenericError(xmlGenericErrorContext,
				    "Found public match %s\n", cur->name);
			catal->depth--;
			return(xmlStrdup(cur->URL));
		    }
		    break;
		case XML_CATA_DELEGATE_PUBLIC:
		    if (!xmlStrncmp(pubID, cur->name, xmlStrlen(cur->name)) &&
			(cur->prefer == XML_CATA_PREFER_PUBLIC))
			haveDelegate++;
		    break;
		case XML_CATA_NEXT_CATALOG:
		    if (sysID == NULL)
			haveNext++;
		    break;
		default:
		    break;
	    }
	    cur = cur->next;
	}
	if (haveDelegate) {
	    const xmlChar *delegates[MAX_DELEGATE];
	    int nbList = 0, i;

	    /*
	     * Assume the entries have been sorted by decreasing substring
	     * matches when the list was produced.
	     */
	    cur = catal;
	    while (cur != NULL) {
		if ((cur->type == XML_CATA_DELEGATE_PUBLIC) &&
		    (cur->prefer == XML_CATA_PREFER_PUBLIC) &&
		    (!xmlStrncmp(pubID, cur->name, xmlStrlen(cur->name)))) {

		    for (i = 0;i < nbList;i++)
			if (xmlStrEqual(cur->URL, delegates[i]))
			    break;
		    if (i < nbList) {
			cur = cur->next;
			continue;
		    }
		    if (nbList < MAX_DELEGATE)
			delegates[nbList++] = cur->URL;
			    
		    if (cur->children == NULL) {
			xmlFetchXMLCatalogFile(cur);
		    }
		    if (cur->children != NULL) {
			if (xmlDebugCatalogs)
			    xmlGenericError(xmlGenericErrorContext,
				    "Trying public delegate %s\n", cur->URL);
			ret = xmlCatalogListXMLResolve(
				cur->children, pubID, NULL);
			if (ret != NULL) {
			    catal->depth--;
			    return(ret);
			}
		    }
		}
		cur = cur->next;
	    }
	    /*
	     * Apply the cut algorithm explained in 4/
	     */
	    catal->depth--;
	    return(XML_CATAL_BREAK);
	}
    }
    if (haveNext) {
	cur = catal;
	while (cur != NULL) {
	    if (cur->type == XML_CATA_NEXT_CATALOG) {
		if (cur->children == NULL) {
		    xmlFetchXMLCatalogFile(cur);
		}
		if (cur->children != NULL) {
		    ret = xmlCatalogListXMLResolve(cur->children, pubID, sysID);
		    if (ret != NULL) {
			catal->depth--;
			return(ret);
		    }
		}
	    }
	    cur = cur->next;
	}
    }

    catal->depth--;
    return(NULL);
}

/**
 * xmlCatalogXMLResolveURI:
 * @catal:  a catalog list
 * @URI:  the URI
 * @sysID:  the system ID string
 *
 * Do a complete resolution lookup of an External Identifier for a
 * list of catalog entries.
 *
 * Implements (or tries to) 7.2.2. URI Resolution
 * from http://www.oasis-open.org/committees/entity/spec-2001-08-06.html
 *
 * Returns the URI of the resource or NULL if not found
 */
static xmlChar *
xmlCatalogXMLResolveURI(xmlCatalogEntryPtr catal, const xmlChar *URI) {
    xmlChar *ret = NULL;
    xmlCatalogEntryPtr cur;
    int haveDelegate = 0;
    int haveNext = 0;
    xmlCatalogEntryPtr rewrite = NULL;
    int lenrewrite = 0, len;

    if (catal == NULL)
	return(NULL);

    if (URI == NULL)
	return(NULL);

    /*
     * First tries steps 2/ 3/ 4/ if a system ID is provided.
     */
    cur = catal;
    haveDelegate = 0;
    while (cur != NULL) {
	switch (cur->type) {
	    case XML_CATA_URI:
		if (xmlStrEqual(URI, cur->name)) {
		    if (xmlDebugCatalogs)
			xmlGenericError(xmlGenericErrorContext,
				"Found URI match %s\n", cur->name);
		    return(xmlStrdup(cur->URL));
		}
		break;
	    case XML_CATA_REWRITE_URI:
		len = xmlStrlen(cur->name);
		if ((len > lenrewrite) &&
		    (!xmlStrncmp(URI, cur->name, len))) {
		    lenrewrite = len;
		    rewrite = cur;
		}
		break;
	    case XML_CATA_DELEGATE_URI:
		if (!xmlStrncmp(URI, cur->name, xmlStrlen(cur->name)))
		    haveDelegate++;