I have spotted the biggest bottleneck in "bdiff.c". Actually it was pretty easy to find after I recompiled the python interpreter and mercurial for profiling. In "bdiff.c" function "equatelines" allocates the minimum hash table size, which can lead to tons of collisions. I introduced an "overcommit" factor of 16, this is, I allocate 16 times more memory than the minimum value. Overcommiting 128 times does not improve the performance over the 16-times case.

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"""

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i18n.py - internationalization support for mercurial

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Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>

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This software may be used and distributed according to the terms

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of the GNU General Public License, incorporated herein by reference.

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"""

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import gettext

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t = gettext.translation('hg', fallback=1)

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gettext = t.gettext

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_ = gettext