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| author |  Shawn O. Pearce <spearce@spearce.org> | 2007-08-01 10:23:08 -0400 |
|---|---|---|
| committer | Shawn O. Pearce <spearce@spearce.org> | 2007-08-19 03:38:36 -0400 |
| commit | ac053c02029d88c7ed4d7e92949a1586eb3f7704 (patch) | |
| tree | 84e5e58df838e7f27d8cee33cb1fae6d0f7b6917 /Documentation | |
| parent | Make trailing LF optional for all fast-import commands (diff) | |
| download | tgif-ac053c02029d88c7ed4d7e92949a1586eb3f7704.tar.xz | |
Allow frontends to bidirectionally communicate with fast-import
The existing checkpoint command is very useful to force fast-import
to dump the branches out to disk so that standard Git tools can
access them and the objects they refer to. However there was not a
way to know when fast-import had finished executing the checkpoint
and it was safe to read those refs.
The progress command can be used to make fast-import output any
message of the frontend's choosing to standard out. The frontend
can scan for these messages using select() or poll() to monitor a
pipe connected to the standard output of fast-import.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/git-fast-import.txt | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/Documentation/git-fast-import.txt b/Documentation/git-fast-import.txt index 1644b90cea..0a019dd2e5 100644 --- a/Documentation/git-fast-import.txt +++ b/Documentation/git-fast-import.txt @@ -298,6 +298,11 @@ and control the current import process. More detailed discussion This command is optional and is not needed to perform an import. +`progress`:: + Causes fast-import to echo the entire line to its own + standard output. This command is optional and is not needed + to perform an import. + `commit` ~~~~~~~~ Create or update a branch with a new commit, recording one logical @@ -775,6 +780,31 @@ explicit checkpointing may not be necessary. The `LF` after the command is optional (it used to be required). +`progress` +~~~~~~~~~~ +Causes fast-import to print the entire `progress` line unmodified to +its standard output channel (file descriptor 1) when the command is +processed from the input stream. The command otherwise has no impact +on the current import, or on any of fast-import's internal state. + +.... + 'progress' SP <any> LF + LF? +.... + +The `<any>` part of the command may contain any sequence of bytes +that does not contain `LF`. The `LF` after the command is optional. +Callers may wish to process the output through a tool such as sed to +remove the leading part of the line, for example: + +==== + frontend | git-fast-import | sed 's/^progress //' +==== + +Placing a `progress` command immediately after a `checkpoint` will +inform the reader when the `checkpoint` has been completed and it +can safely access the refs that fast-import updated. + Tips and Tricks --------------- The following tips and tricks have been collected from various @@ -867,6 +897,15 @@ This will take longer, but will also produce a smaller packfile. You only need to expend the effort once, and everyone using your project will benefit from the smaller repository. +Include Some Progress Messages +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Every once in a while have your frontend emit a `progress` message +to fast-import. The contents of the messages are entirely free-form, +so one suggestion would be to output the current month and year +each time the current commit date moves into the next month. +Your users will feel better knowing how much of the data stream +has been processed. + Packfile Optimization --------------------- |