Gregory Szorc <gregory.szorc@gmail.com> [Thu, 14 Jan 2016 13:34:59 -0800] rev 27895
scmutil: support background file closing
Closing files that have been appended to is relatively slow on
Windows/NTFS. This makes several Mercurial operations slower on
Windows.
The workaround to this issue is conceptually simple: use multiple
threads for I/O. Unfortunately, Python doesn't scale well to multiple
threads because of the GIL. And, refactoring our code to use threads
everywhere would be a huge undertaking. So, we decide to tackle this
problem by starting small: establishing a thread pool for closing
files.
This patch establishes a mechanism for closing file handles on separate
threads. The coordinator object is basically a queue of file handles to
operate on and a thread pool consuming from the queue.
When files are opened through the VFS layer, the caller can specify
that delay closing is allowed.
A proxy class for file handles has been added. We must use a proxy
because it isn't possible to modify __class__ on built-in types. This
adds some overhead. But as future patches will show, this overhead
is cancelled out by the benefit of closing file handles on background
threads.
Yuya Nishihara <yuya@tcha.org> [Tue, 12 Jan 2016 23:56:48 +0900] rev 27894
templatekw: add {namespaces} keyword
This provides a general-purpose interface to all custom namespaces.
The {namespaces} keyword honors the definition order of namespaces as they
are kept by sortdict.
Yuya Nishihara <yuya@tcha.org> [Tue, 12 Jan 2016 23:53:56 +0900] rev 27893
templatekw: move shownames() helper to be sorted alphabetically
I'll add shownamespaces(), which is similar to this function. I want to put
them nearby.