webapp: Progess bar fixes for many types of special remotes.

There was confusion in different parts of the progress bar code about
whether an update contained the total number of bytes transferred, or the
number of bytes transferred since the last update. One way this bug
showed up was progress bars that seemed to stick at zero for a long time.
In order to fix it comprehensively, I add a new BytesProcessed data type,
that is explicitly a total quantity of bytes, not a delta.

Note that this doesn't necessarily fix every problem with progress bars.
Particularly, buffering can now cause progress bars to seem to run ahead
of transfers, reaching 100% when data is still being uploaded.

1 files changed, 5 insertions, 0 deletions

diff --git a/doc/bugs/No_progress_bars_with_S3.mdwn b/doc/bugs/No_progress_bars_with_S3.mdwn
index 907b3cb11..afa7ba5ee 100644
--- a/doc/bugs/No_progress_bars_with_S3.mdwn
+++ b/doc/bugs/No_progress_bars_with_S3.mdwn
@@ -19,3 +19,8 @@ I expect a changing status bar and percentage. Instead I see no changes when an
 When uploading local data to an S3 remote, I see no progress bars. The progress bar area on active uploads stays the same grey as the bar on queued uploads. The status does not change from "0% of...". The uploads are completing, but this makes it very difficult to judge their activity.
 
 The only remotes I currently have setup are S3 special remotes, so I cannot say whether progress bars are working for uploads to other remote types.
+
+> [[done]], this turned out to be a confusion in the progress code;
+> parts were expecting a full number of bytes since the start, while
+> other parts were sending the number of bytes in a chunk. Result was
+> progress bars stuck at 0% often. --[[Joey]]