[PATCH] new and improved ap_vrprintf fix to handle > 4K

[Cody Sherr]

The purpose of this patch is to allow vrprintf to work for larger than 4k
sized fmt strings by providing a flushing function for vformatter to use
when the buffer fills up.

regards,

-- 
Cody Sherr

Engineer
Covalent Technologies

phone: (415)536-5292
email: [EMAIL PROTECTED]

Index: protocol.c
===================================================================
RCS file: /home/cvspublic/httpd-2.0/server/protocol.c,v
retrieving revision 1.38
diff -u -r1.38 protocol.c
--- protocol.c  2001/08/07 16:40:25     1.38
+++ protocol.c  2001/08/15 20:59:39
@@ -1133,19 +1133,63 @@
     return nbyte;
 }

+const int BUFSIZE = 4096;
+static char vrprintf_buf[4096];
+
+struct ap_vrprintf_data {
+    apr_vformatter_buff_t vbuff;
+    request_rec *r;
+};
+
+static apr_status_t r_flush(apr_vformatter_buff_t *buff)
+{
+    /* callback function passed to ap_vformatter to be called when
+     * vformatter needs to write into buff and buff.curpos > buff.endpos */
+
+    /* ap_vrprintf_data passed as a apr_vformatter_buff_t, which is then
+     * "downcast" to an ap_vrprintf_data */
+    struct ap_vrprintf_data *vd = (struct ap_vrprintf_data*)buff;
+
+    if (vd->r->connection->aborted)
+        return -1;
+
+    /* r_flush is called when vbuff is completely full */
+    if (buffer_output(vd->r, vrprintf_buf, BUFSIZE)) {
+       return -1;
+    }
+
+    /* reset the buffer position */
+    vd->vbuff.curpos = vrprintf_buf;
+    vd->vbuff.endpos = vrprintf_buf + BUFSIZE;
+
+    return APR_SUCCESS;
+}
+
 AP_DECLARE(int) ap_vrprintf(request_rec *r, const char *fmt, va_list va)
 {
-    char buf[4096];
     apr_size_t written;
+    struct ap_vrprintf_data vd;
+
+    vd.vbuff.curpos = vrprintf_buf;
+    vd.vbuff.endpos = vrprintf_buf + BUFSIZE;
+    vd.r = r;

     if (r->connection->aborted)
         return -1;

-    /* ### fix this mechanism to allow more than 4K of output */
-    written = apr_vsnprintf(buf, sizeof(buf), fmt, va);
+    written = apr_vformatter(r_flush, &vd.vbuff, fmt, va);
+    /* tack on null terminator on remaining string */
+    *(vd.vbuff.curpos) = '\0';

-    if (buffer_output(r, buf, written) != APR_SUCCESS)
-        return -1;
+    if (written != -1) {
+       int n = vd.vbuff.curpos - vrprintf_buf;
+
+       /* last call to buffer_output, to finish clearing the buffer */
+       if (buffer_output(r, vrprintf_buf,n) != APR_SUCCESS)
+           return -1;
+
+       written += n;
+    }

     return written;
 }