Summary:
To use linelog, we need to be able to translate between hg commit hashes and
linelog revision numbers. This diff implements such a revmap using the most
direct way.
The revmap also contains an extra "flag" for each revision, which will be used
to mark if the revision is in the main branch or not, to handle merge commits.
Test Plan:
`import revmap` from IPython and test its interface manually. Also have a
simple script to get some idea about its perf with 10000 revisions:
```
import contextlib, time, os, random, revmap, sys
@contextlib.contextmanager
def benchmark(msg):
sys.stderr.write('%s: ' % msg)
t1 = time.time()
yield
t2 = time.time()
sys.stderr.write('%f seconds\n' % (t2 - t1))
def randomid():
return ''.join([chr(random.randint(0,255)) for _ in xrange(0, 20)])
rm = revmap.revmap('revmap1')
with benchmark('insert 10000 random revisions'): # ~0.3 seconds
for i in xrange(0, 10000):
rm.append(randomid(), flag=1, flush=False)
with benchmark('writing to disk'): # 0.02 seconds
rm.flush()
os.rename('revmap1', 'revmap2')
with benchmark('loading'): # ~0.015 seconds
rm = revmap.revmap('revmap2')
```
Reviewers: ttung, #sourcecontrol, ikostia
Reviewed By: ikostia
Subscribers: ikostia, mjpieters
Differential Revision: https://phabricator.intern.facebook.com/D3709706
Signature: t1:3709706:1471936489:0bbe35ed39a2af3f06e1000c4f9674149ad43995