view hgext/infinitepush/README @ 45095:8e04607023e5

procutil: ensure that procutil.std{out,err}.write() writes all bytes

Python 3 offers different kind of streams and it’s not guaranteed for all of
them that calling write() writes all bytes.

When Python is started in unbuffered mode, sys.std{out,err}.buffer are
instances of io.FileIO, whose write() can write less bytes for
platform-specific reasons (e.g. Linux has a 0x7ffff000 bytes maximum and could
write less if interrupted by a signal; when writing to Windows consoles, it’s
limited to 32767 bytes to avoid the "not enough space" error). This can lead to
silent loss of data, both when using sys.std{out,err}.buffer (which may in fact
not be a buffered stream) and when using the text streams sys.std{out,err}
(I’ve created a CPython bug report for that:
https://bugs.python.org/issue41221).

Python may fix the problem at some point. For now, we implement our own wrapper
for procutil.std{out,err} that calls the raw stream’s write() method until all
bytes have been written. We don’t use sys.std{out,err} for larger writes, so I
think it’s not worth the effort to patch them.

## What is it?

This extension adds ability to save certain pushes to a remote blob store
as bundles and to serve commits from remote blob store.
The revisions are stored on disk or in everstore.
The metadata are stored in sql or on disk.

## Config options

infinitepush.branchpattern: pattern to detect a scratchbranch, example
                            're:scratch/.+'

infinitepush.indextype: disk or sql for the metadata
infinitepush.reponame: only relevant for sql metadata backend, reponame to put in
                       sql

infinitepush.indexpath: only relevant for ondisk metadata backend, the path to
                        store the index on disk. If not set will be under .hg
                        in a folder named filebundlestore

infinitepush.storepath: only relevant for ondisk metadata backend, the path to
                        store the bundles. If not set, it will be
                        .hg/filebundlestore