[libvirt] [PATCH 2/3] xml: add another convenience function
Daniel Veillard
veillard at redhat.com
Fri Aug 19 08:48:47 UTC 2011
On Thu, Aug 18, 2011 at 03:40:48PM -0600, Eric Blake wrote:
> Often, we want to use XPath functions on the just-parsed document;
> fold this into the parser function for convenience.
>
> * src/util/xml.h (virXMLParseHelper): Add argument.
> (virXMLParseStrHelper, virXMLParseFileHelper): Delete.
> (virXMLParseCtxt, virXMLParseStringCtxt, virXMLParseFileCtxt): New
> macros.
> * src/libvirt_private.syms (xml.h): Remove deleted functions.
> * src/util/xml.c (virXMLParseHelper): Add argument.
> (virXMLParseStrHelper, virXMLParseFileHelper): Delete.
> ---
> src/libvirt_private.syms | 2 -
> src/util/xml.c | 53 ++++++++---------------------
> src/util/xml.h | 84 +++++++++++++++++++++++++++++++++++++++++-----
> 3 files changed, 90 insertions(+), 49 deletions(-)
>
> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> index acae122..0618b49 100644
> --- a/src/libvirt_private.syms
> +++ b/src/libvirt_private.syms
> @@ -1164,9 +1164,7 @@ virKeycodeValueFromString;
> virKeycodeValueTranslate;
>
> # xml.h
> -virXMLParseFileHelper;
> virXMLParseHelper;
> -virXMLParseStrHelper;
> virXMLPropString;
> virXPathBoolean;
> virXPathInt;
> diff --git a/src/util/xml.c b/src/util/xml.c
> index 05317ea..d301af6 100644
> --- a/src/util/xml.c
> +++ b/src/util/xml.c
> @@ -662,6 +662,7 @@ catchXMLError(void *ctx, const char *msg ATTRIBUTE_UNUSED, ...)
> * @filename: file to be parsed or NULL if string parsing is requested
> * @xmlStr: XML string to be parsed in case filename is NULL
> * @url: URL of XML document for string parser
> + * @ctxt: optional pointer to populate with new context pointer
> *
> * Parse XML document provided either as a file or a string. The function
> * guarantees that the XML document contains a root element.
> @@ -672,7 +673,8 @@ xmlDocPtr
> virXMLParseHelper(int domcode,
> const char *filename,
> const char *xmlStr,
> - const char *url)
> + const char *url,
> + xmlXPathContextPtr *ctxt)
> {
> struct virParserData private;
> xmlParserCtxtPtr pctxt;
> @@ -680,8 +682,10 @@ virXMLParseHelper(int domcode,
>
> /* Set up a parser context so we can catch the details of XML errors. */
> pctxt = xmlNewParserCtxt();
> - if (!pctxt || !pctxt->sax)
> + if (!pctxt || !pctxt->sax) {
> + virReportOOMError();
> goto error;
> + }
>
> private.domcode = domcode;
> pctxt->_private = &private;
> @@ -705,6 +709,15 @@ virXMLParseHelper(int domcode,
> goto error;
> }
>
> + if (ctxt) {
> + *ctxt = xmlXPathNewContext(xml);
> + if (!*ctxt) {
> + virReportOOMError();
> + goto error;
> + }
> + (*ctxt)->node = xmlDocGetRootElement(xml);
> + }
> +
> cleanup:
> xmlFreeParserCtxt(pctxt);
>
> @@ -720,39 +733,3 @@ error:
> }
> goto cleanup;
> }
> -
> -/**
> - * virXMLParseStrHelper:
> - * @domcode: error domain of the caller, usually VIR_FROM_THIS
> - * @xmlStr: XML string to be parsed in case filename is NULL
> - * @url: URL of XML document for string parser
> - *
> - * Parse XML document provided as a string. The function guarantees that
> - * the XML document contains a root element.
> - *
> - * Returns parsed XML document.
> - */
> -xmlDocPtr
> -virXMLParseStrHelper(int domcode,
> - const char *xmlStr,
> - const char *url)
> -{
> - return virXMLParseHelper(domcode, NULL, xmlStr, url);
> -}
> -
> -/**
> - * virXMLParseFileHelper:
> - * @domcode: error domain of the caller, usually VIR_FROM_THIS
> - * @filename: file to be parsed
> - *
> - * Parse XML document provided as a file. The function guarantees that
> - * the XML document contains a root element.
> - *
> - * Returns parsed XML document.
> - */
> -xmlDocPtr
> -virXMLParseFileHelper(int domcode,
> - const char *filename)
> -{
> - return virXMLParseHelper(domcode, filename, NULL, NULL);
> -}
> diff --git a/src/util/xml.h b/src/util/xml.h
> index b342e83..d30e066 100644
> --- a/src/util/xml.h
> +++ b/src/util/xml.h
> @@ -53,23 +53,89 @@ int virXPathNodeSet(const char *xpath,
> char * virXMLPropString(xmlNodePtr node,
> const char *name);
>
> +/* Internal function; prefer the macros below. */
> xmlDocPtr virXMLParseHelper(int domcode,
> const char *filename,
> const char *xmlStr,
> - const char *url);
> -xmlDocPtr virXMLParseStrHelper(int domcode,
> - const char *xmlStr,
> - const char *url);
> -xmlDocPtr virXMLParseFileHelper(int domcode,
> - const char *filename);
> + const char *url,
> + xmlXPathContextPtr *pctxt);
>
> +/**
> + * virXMLParse:
> + * @filename: file to parse, or NULL for string parsing
> + * @xmlStr: if @filename is NULL, a string to parse
> + * @url: if @filename is NULL, an optional filename to attribute the parse to
> + *
> + * Parse xml from either a file or a string.
> + *
> + * Return the parsed document object, or NULL on failure.
> + */
> # define virXMLParse(filename, xmlStr, url) \
> - virXMLParseHelper(VIR_FROM_THIS, filename, xmlStr, url)
> + virXMLParseHelper(VIR_FROM_THIS, filename, xmlStr, url, NULL)
>
> +/**
> + * virXMLParseString:
> + * @xmlStr: a string to parse
> + * @url: an optional filename to attribute the parse to
> + *
> + * Parse xml from a string.
> + *
> + * Return the parsed document object, or NULL on failure.
> + */
> # define virXMLParseString(xmlStr, url) \
> - virXMLParseStrHelper(VIR_FROM_THIS, xmlStr, url)
> + virXMLParseHelper(VIR_FROM_THIS, NULL, xmlStr, url, NULL)
>
> +/**
> + * virXMLParseFile:
> + * @filename: file to parse
> + *
> + * Parse xml from a file.
> + *
> + * Return the parsed document object, or NULL on failure.
> + */
> # define virXMLParseFile(filename) \
> - virXMLParseFileHelper(VIR_FROM_THIS, filename)
> + virXMLParseHelper(VIR_FROM_THIS, filename, NULL, NULL, NULL)
> +
> +/**
> + * virXMLParseCtxt:
> + * @filename: file to parse, or NULL for string parsing
> + * @xmlStr: if @filename is NULL, a string to parse
> + * @url: if @filename is NULL, an optional filename to attribute the parse to
> + * @pctxt: if non-NULL, populate with a new context object on success,
> + * with (*pctxt)->node pre-set to the root node
> + *
> + * Parse xml from either a file or a string.
> + *
> + * Return the parsed document object, or NULL on failure.
> + */
> +# define virXMLParseCtxt(filename, xmlStr, url, pctxt) \
> + virXMLParseHelper(VIR_FROM_THIS, filename, xmlStr, url, pctxt)
> +
> +/**
> + * virXMLParseStringCtxt:
> + * @xmlStr: a string to parse
> + * @url: an optional filename to attribute the parse to
> + * @pctxt: if non-NULL, populate with a new context object on success,
> + * with (*pctxt)->node pre-set to the root node
> + *
> + * Parse xml from a string.
> + *
> + * Return the parsed document object, or NULL on failure.
> + */
> +# define virXMLParseStringCtxt(xmlStr, url, pctxt) \
> + virXMLParseHelper(VIR_FROM_THIS, NULL, xmlStr, url, pctxt)
> +
> +/**
> + * virXMLParseFileCtxt:
> + * @filename: file to parse
> + * @pctxt: if non-NULL, populate with a new context object on success,
> + * with (*pctxt)->node pre-set to the root node
> + *
> + * Parse xml from a file.
> + *
> + * Return the parsed document object, or NULL on failure.
> + */
> +# define virXMLParseFileCtxt(filename, pctxt) \
> + virXMLParseHelper(VIR_FROM_THIS, filename, NULL, NULL, pctxt)
>
> #endif /* __VIR_XML_H__ */
ACK to the overall cleanup, I'm just a bit dubious about
xmlXPathContextPtr initialization in the helper, as I like to have
allocations and frees matched to the same level. It's easier to forget
to free the context if one doesn't "see" it allocated. But it's a minor
concern.
Daniel
--
Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/
daniel at veillard.com | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library http://libvirt.org/
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