Re: [xml] PATCH: implement xmlSaveToBuffer()

[Geert Jansen <geert boskant nl>]

Daniel Veillard wrote:
> > Any reason why this couldn't or shouldn't be done the same way 
> > xmlNewTextWriterMemory is done?
> > Would only require the addition of write and close callbacks and not 
> > require any of the other new stuff from the patch.
> >     
>
>   Right, while Geert patch is correct, an approach where you reuse the
> I/O callback to fill up a buffer looks cleaner to me.
>   
OK -- please see the attached patch.

Regards,
Geert

diff -ur libxml2-2.6.22.orig/include/libxml/xmlIO.h libxml2-2.6.22/include/libxml/xmlIO.h
--- libxml2-2.6.22.orig/include/libxml/xmlIO.h  2005-07-27 22:59:37.000000000 +0200
+++ libxml2-2.6.22/include/libxml/xmlIO.h       2005-11-07 22:22:17.000000000 +0100
@@ -232,6 +232,10 @@
                                         xmlCharEncodingHandlerPtr encoder);
 
 XMLPUBFUN xmlOutputBufferPtr XMLCALL
+       xmlOutputBufferCreateBuffer     (xmlBufferPtr buffer,
+                                        xmlCharEncodingHandlerPtr encoder);
+
+XMLPUBFUN xmlOutputBufferPtr XMLCALL
        xmlOutputBufferCreateFd         (int fd,
                                         xmlCharEncodingHandlerPtr encoder);
 
diff -ur libxml2-2.6.22.orig/include/libxml/xmlsave.h libxml2-2.6.22/include/libxml/xmlsave.h
--- libxml2-2.6.22.orig/include/libxml/xmlsave.h        2005-09-12 17:34:25.000000000 +0200
+++ libxml2-2.6.22/include/libxml/xmlsave.h     2005-11-06 22:49:37.000000000 +0100
@@ -45,14 +45,12 @@
                xmlSaveToFilename       (const char *filename,
                                         const char *encoding,
                                         int options);
-/******
-  Not yet implemented.
 
 XMLPUBFUN xmlSaveCtxtPtr XMLCALL
                xmlSaveToBuffer         (xmlBufferPtr buffer,
                                         const char *encoding,
                                         int options);
- ******/
+
 XMLPUBFUN xmlSaveCtxtPtr XMLCALL
                xmlSaveToIO             (xmlOutputWriteCallback iowrite,
                                         xmlOutputCloseCallback ioclose,
diff -ur libxml2-2.6.22.orig/xmlIO.c libxml2-2.6.22/xmlIO.c
--- libxml2-2.6.22.orig/xmlIO.c 2005-08-05 15:53:39.000000000 +0200
+++ libxml2-2.6.22/xmlIO.c      2005-11-07 22:37:38.000000000 +0100
@@ -860,6 +860,42 @@
     return(ret);
 }
 
+#ifdef LIBXML_OUTPUT_ENABLED
+/**
+ * xmlBufferWrite:
+ * @context:  the xmlBuffer
+ * @buffer:  the data to write
+ * @len:  number of bytes to write
+ *
+ * Write @len bytes from @buffer to the xml buffer
+ *
+ * Returns the number of bytes written
+ */
+static int
+xmlBufferWrite (void * context, const char * buffer, int len) {
+    int ret;
+
+    ret = xmlBufferAdd((xmlBufferPtr) context, (const xmlChar *) buffer, len);
+    if (ret != 0)
+        return -1;
+    return(len);
+}
+
+/**
+ * xmlBufferClose:
+ * @context:  the xmlBuffer
+ *
+ * Close a buffer
+ *
+ * Returns 0 or -1 in case of error
+ */
+static int
+xmlBufferClose (void * context) {
+    (void) context;
+    return(0);
+}
+#endif
+
 #ifdef HAVE_ZLIB_H
 /************************************************************************
  *                                                                     *
@@ -2436,6 +2472,33 @@
 
     return(ret);
 }
+
+/**
+ * xmlOutputBufferCreateBuffer:
+ * @buffer:  a xmlBufferPtr
+ * @encoder:  the encoding converter or NULL
+ *
+ * Create a buffered output for the progressive saving to a xmlBuffer
+ *
+ * Returns the new parser output or NULL
+ */
+xmlOutputBufferPtr
+xmlOutputBufferCreateBuffer(xmlBufferPtr buffer,
+                            xmlCharEncodingHandlerPtr encoder) {
+    xmlOutputBufferPtr ret;
+
+    if (buffer == NULL) return(NULL);
+
+    ret = xmlAllocOutputBuffer(encoder);
+    if (ret != NULL) {
+        ret->context = buffer;
+        ret->writecallback = xmlBufferWrite;
+        ret->closecallback = xmlBufferClose;
+    }
+
+    return(ret);
+}
+
 #endif /* LIBXML_OUTPUT_ENABLED */
 
 /**
diff -ur libxml2-2.6.22.orig/xmlsave.c libxml2-2.6.22/xmlsave.c
--- libxml2-2.6.22.orig/xmlsave.c       2005-09-12 17:35:07.000000000 +0200
+++ libxml2-2.6.22/xmlsave.c    2005-11-06 23:06:09.000000000 +0100
@@ -1473,13 +1473,36 @@
  * with the encoding and the options given
  *
  * Returns a new serialization context or NULL in case of error.
+ */
+
 xmlSaveCtxtPtr
 xmlSaveToBuffer(xmlBufferPtr buffer, const char *encoding, int options)
 {
-    TODO
-    return(NULL);
+    xmlSaveCtxtPtr ret;
+    xmlOutputBufferPtr out_buff;
+    xmlCharEncodingHandlerPtr handler;
+
+    ret = xmlNewSaveCtxt(encoding, options);
+    if (ret == NULL) return(NULL);
+
+    if (encoding != NULL) {
+        handler = xmlFindCharEncodingHandler(encoding);
+        if (handler == NULL) {
+            xmlFree(ret);
+            return(NULL);
+        }
+    } else
+        handler = NULL;
+    out_buff = xmlOutputBufferCreateBuffer(buffer, handler);
+    if (out_buff == NULL) {
+        xmlFree(ret);
+        if (handler) xmlCharEncCloseFunc(handler);
+        return(NULL);
+    }
+
+    ret->buf = out_buff;
+    return(ret);
 }
- */
 
 /**
  * xmlSaveToIO: