[FFmpeg-devel] [RFC] url_write()

[Michael Niedermayer]

On Thu, Sep 30, 2010 at 08:09:46PM +0200, Reimar D?ffinger wrote:
> On Thu, Sep 30, 2010 at 01:20:33PM +0200, Michael Niedermayer wrote:
> > What do users of url_write() prefer
> > should we always call it in a loop in the url_write() wraper or
> > should all uses be fixed and a url_write_complete() be added similar to
> > url_read()
> > ?
> 
> A separate url_write_complete IMO is useless. The big difference compared to reading
> is that if latency is an issue in the write function, it is possible
> to just buffer the data.
> Thus I think there is no point in a write function that does
> incomplete writes.

Patch below, will commit in a day if there are no objections

commit 92843bc433f7d2964c9b1c0f0b7df9256fadf24b
Author: Michael Niedermayer <michaelni at gmx.at>
Date:   Tue Oct 5 21:58:29 2010 +0200

    Fix url_write() so it does not stop in the middle as callers do not expect this.
    This fix is done in line with how url_read_complete() works.

diff --git a/libavformat/avio.c b/libavformat/avio.c
index 4399878..7c760e2 100644
--- a/libavformat/avio.c
+++ b/libavformat/avio.c
@@ -240,14 +240,29 @@ int url_read_complete(URLContext *h, unsigned char *buf, int size)

 int url_write(URLContext *h, const unsigned char *buf, int size)
 {
-    int ret;
+    int len= 0;
+    int fast_retries= 5;
     if (!(h->flags & (URL_WRONLY | URL_RDWR)))
         return AVERROR(EIO);
     /* avoid sending too big packets */
     if (h->max_packet_size && size > h->max_packet_size)
         return AVERROR(EIO);
-    ret = h->prot->url_write(h, buf, size);
-    return ret;
+
+    while(len<size){
+        int ret= h->prot->url_write(h, buf+len, size-len);
+        if (ret == AVERROR(EAGAIN)) {
+            ret= 0;
+            if (fast_retries){
+                fast_retries--;
+            }else
+                usleep(1000);
+        } else if (ret < 1)
+            return ret < 0 ? ret : len;
+        if (ret)
+           fast_retries = FFMAX(fast_retries, 2);
+        len += ret;
+    }
+    return len;
 }

 int64_t url_seek(URLContext *h, int64_t pos, int whence)

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

No snowflake in an avalanche ever feels responsible. -- Voltaire
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: Digital signature
URL: <http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/attachments/20101005/6de7fbac/attachment.pgp>