Improve the way the chunking filter handles zero-length buckets,

and fix the comment explaining how to reduce the incidence of tiny chunks.
Submitted by:	Jeff Trawick
Reviewed by:	Tony Finch

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@86222 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/modules/http/http_core.c b/modules/http/http_core.c
index b533a80f98db9667863b9736af17f19db0adde02..61279f2fd5963913d9bbe41a76bd0baa8e41b6d7 100644 (file)
--- a/modules/http/http_core.c
+++ b/modules/http/http_core.c
@@ -2951,25 +2951,31 @@ static apr_status_t chunk_filter(ap_filter_t *f, ap_bucket_brigade *b)
                break;
            }
            else if (e->length == -1) {
-                /* Bucket Of Interdeterminate Length (BOIL). (e.g. a pipe) */
-
+                /* unknown amount of data (e.g. a pipe) */
                const char *data;
                apr_ssize_t len;
 
-                /* this will construct a new bucket */
                rv = e->read(e, &data, &len, 1);
                if (rv != APR_SUCCESS) {
                    return rv;
                }
-               bytes += len;
-
-                /*
-                 * We split between the new bucket and the BOIL. We'll come
-                 * back for the rest of the brigade later (reading more out
-                 * of the BOIL, possibly splitting again
-                 */
-               more = ap_brigade_split(b, AP_BUCKET_NEXT(e));
-               break;
+               if (len > 0) {
+                   /*
+                    * There may be a new next bucket representing the
+                    * rest of the data stream on which a read() may
+                    * block so we pass down what we have so far.
+                    */
+                   bytes += len;
+                   more = ap_brigade_split(b, AP_BUCKET_NEXT(e));
+                   break;
+               }
+               else {
+                   /* If there was nothing in this bucket then we can
+                    * safely move on to the next one without pausing
+                    * to pass down what we have counted up so far.
+                    */
+                   continue;
+               }
            }
            else {
                bytes += e->length;
@@ -2978,7 +2984,8 @@ static apr_status_t chunk_filter(ap_filter_t *f, ap_bucket_brigade *b)
 
        /*
         * XXX: if there aren't very many bytes at this point it may
-        * be a good idea to set them aside and return for more.
+        * be a good idea to set them aside and return for more,
+        * unless we haven't finished counting this brigade yet.
         */
 
         /* if there are content bytes, then wrap them in a chunk */