hg: make cachedlocalrepo cache appropriate repoview object
Before this patch, 'cachedlocalrepo' always caches "visible" repoview
object, because 'cachedlocalrepo' uses "visible" repoview returned by
'hg.repository()' without any additional processing.
If the client of 'cachedlocalrepo' wants "served" repoview, some
objects to be cached are discarded unintentionally.
1. 'cachedlocalrepo' newly caches "visible" repoview object
(call it VIEW1)
2. 'cachedlocalrepo' returns VIEW1 to the client of it at 'fetch()'
3. the client gets "served" repoview object by 'filtered("served")'
on VIEW1 (call this "served" repoview VIEW2)
4. accessing to 'repo.changelog' implies:
- instantiation of changelog via 'localrepository.changelog'
- instantiation of "filtered changelog" via 'repoview.changelog'
5. "filtered changelog" above is cached in VIEW2
6. VIEW2 is discarded after processing, because there is no
reference to it
7. 'cachedlocalrepo' returns VIEW1 cached at (1) above to the
client at next 'fetch()'
8. 'filtered("served")' on VIEW1 at the client side creates new
"served" repoview again, because VIEW1 is "visible"
(call this new "served" repoview VIEW3)
9. accessing to 'repo.changelog' implies instantiation of filtered
changelog again, because "filtered changelog" is cached in
VIEW2 at (5), but not in VIEW3 currently used
10. (go to (7) above)
As described above, "served" repoview object and "filtered changelog"
cached in it are discarded always, even if the repository itself
hasn't been changed since last access.
For example, in the case of 'hgweb_mod.hgweb', "newly caching" occurs,
when:
- all cached objects are already assigned to another threads
(in this case, repoview is created in 'cachedlocalrepo.copy()')
- or, stat of '00changelog.i' is changed from last access
(in this case, repoview is created in 'cachedlocalrepo.fetch()')
once changes are pushed via HTTP, this always occurs.
The root cause of this inefficiency is that 'cachedlocalrepo' always
caches "visible" repoview object, even if the client of it wants
another view.
To make 'cachedlocalrepo' cache appropriate repoview object, this
patch adds additional filtering on the repo object returned by
'hg.repository()'. It is assumed that initial repoview object should
be already filtered by expected view.
After this patch:
- 'filtered("served")' on VIEW1 at (3)/(7) above returns VIEW1
itself, because VIEW1 is now "served", and
- VIEW2 and VIEW3 equal VIEW1
- therefore, "filtered changelog" is cached in VIEW1, and reused
intentionally
# Helper script used for generating history and working copy files and content.
# The file's name corresponds to its history. The number of changesets can
# be specified on the command line. With 2 changesets, files with names like
# content1_content2_content1-untracked are generated. The first two filename
# segments describe the contents in the two changesets. The third segment
# ("content1-untracked") describes the state in the working copy, i.e.
# the file has content "content1" and is untracked (since it was previously
# tracked, it has been forgotten).
#
# This script generates the filenames and their content, but it's up to the
# caller to tell hg about the state.
#
# There are two subcommands:
# filelist <numchangesets>
# state <numchangesets> (<changeset>|wc)
#
# Typical usage:
#
# $ python $TESTDIR/generate-working-copy-states.py state 2 1
# $ hg addremove --similarity 0
# $ hg commit -m 'first'
#
# $ python $TESTDIR/generate-working-copy-states.py state 2 1
# $ hg addremove --similarity 0
# $ hg commit -m 'second'
#
# $ python $TESTDIR/generate-working-copy-states.py state 2 wc
# $ hg addremove --similarity 0
# $ hg forget *_*_*-untracked
# $ rm *_*_missing-*
from __future__ import absolute_import
import os
import sys
# Generates pairs of (filename, contents), where 'contents' is a list
# describing the file's content at each revision (or in the working copy).
# At each revision, it is either None or the file's actual content. When not
# None, it may be either new content or the same content as an earlier
# revisions, so all of (modified,clean,added,removed) can be tested.
def generatestates(maxchangesets, parentcontents):
depth = len(parentcontents)
if depth == maxchangesets + 1:
for tracked in ('untracked', 'tracked'):
filename = "_".join([(content is None and 'missing' or content) for
content in parentcontents]) + "-" + tracked
yield (filename, parentcontents)
else:
for content in (set([None, 'content' + str(depth + 1)]) |
set(parentcontents)):
for combination in generatestates(maxchangesets,
parentcontents + [content]):
yield combination
# retrieve the command line arguments
target = sys.argv[1]
maxchangesets = int(sys.argv[2])
if target == 'state':
depth = sys.argv[3]
# sort to make sure we have stable output
combinations = sorted(generatestates(maxchangesets, []))
# compute file content
content = []
for filename, states in combinations:
if target == 'filelist':
print filename
elif target == 'state':
if depth == 'wc':
# Make sure there is content so the file gets written and can be
# tracked. It will be deleted outside of this script.
content.append((filename, states[maxchangesets] or 'TOBEDELETED'))
else:
content.append((filename, states[int(depth) - 1]))
else:
print >> sys.stderr, "unknown target:", target
sys.exit(1)
# write actual content
for filename, data in content:
if data is not None:
f = open(filename, 'wb')
f.write(data + '\n')
f.close()
elif os.path.exists(filename):
os.remove(filename)