convert: self.heads is a list
self.heads is used as a list throughout convert and never a dictionary.
Initialize it correctly to a list.
convert: don't use long list comprehensions
We are iterating over p4changes. Make the continue condition more clear
and easier to add new conditions in future patches, by removing the list
comprehension and move the condition into the existing for-loop.
changelog: keep track of file end in appender (
issue5444)
Previously, changelog.appender.end() would compute the end of the file by
joining all the current appended data and checking the length. This is an O(n)
operation.
e240e914d226 introduced a seek call before every revlog write, which
means we are hitting this O(n) behavior n times, which causes changelog writes
during a pull to be n^2.
In our large repo, this caused pulling 100k commits to go from 17s to 130s. With
this fix, it's back to 17s.
tests: fix test-bdiff to handle variance between pure and c bdiff code
Obviously we'd rather patch pure to have the same algorithmic win as
the C code, but this is a quick fix for the pure build since pure
isn't wrong, just not as fast as it could be.