Stefan Fuhrmann <stef...@apache.org> writes: > Author: stefan2 > Date: Wed Sep 2 13:04:51 2015 > New Revision: 1700799 > > URL: http://svn.apache.org/r1700799 > Log: > [Combines r1698359 and r170078 into a single commit for better review.] > Introduce a stream wrapper object that adds buffering support to any > readable stream. Use it on the stdin streams in our CL tools. > > As it turns out, parsing data from a stdin byte-by-byte incurs a > massive overhead of 100% internal and 300% system load over a buffered > stream. 'svnadmin load-revprops' sees a 5 times speedup if all data > is in OS disc caches. This is a realistic assumption in a "final sync > and switch over to new repository" scenario. > > The other 2 uses of stdin either have less data to process (svnfsfs > load-index) or parse only a small fraction of the stream (svnadmin load). > > * subversion/include/svn_io.h > (svn_stream_wrap_buffered_read): Declare the new stream constructor API.
[...] If buffering makes difference for how well svnadmin load, load-revprops and svnfsfs load-index behave, can't we use the standard mechanism for that, say, apr_file_open_flags_stdin(..., APR_BUFFERED)? What is the point of reimplementing something that's already a part of the APR? Regards, Evgeny Kotkov
