bundlerepo: dynamically create repository type from base repository
Previously, bundlerepository inherited from localrepo.localrepository.
You simply instantiated a bundlerepository and its __init__ called
localrepo.localrepository.__init__. Things were simple.
Unfortunately, this strategy is limiting because it assumes that
the base repository is a localrepository instance. And it assumes
various properties of localrepository, such as the arguments its
__init__ takes. And it prevents us from changing behavior of
localrepository.__init__ without also having to change derived classes.
Previous and ongoing work to abstract storage revealed these
limitations.
This commit changes the initialization strategy of bundle repositories
to dynamically create a type to represent the repository. Instead of
a static type, we instantiate a new local repo instance via
localrepo.instance(). We then combine its __class__ with
bundlerepository to produce a new type. This ensures that no matter
how localrepo.instance() decides to create a repository object, we
can derive a bundle repo object from it. i.e. localrepo.instance()
could return a type that isn't a localrepository and it would "just
work."
Well, it would "just work" if bundlerepository's custom implementations
only accessed attributes in the documented repository interface. I'm
pretty sure it violates the interface contract in a handful of
places. But we can worry about that another day. This change gets us
closer to doing more clever things around instantiating repository
instances without having to worry about teaching bundlerepository about
them.
.. api::
``bundlerepo.bundlerepository`` is no longer usable on its own.
The class is combined with the class of the base repository it is
associated with at run-time.
New bundlerepository instances can be obtained by calling
``bundlerepo.instance()`` or ``bundlerepo.makebundlerepository()``.
Differential Revision: https://phab.mercurial-scm.org/D4555
from __future__ import absolute_import, print_function
import binascii
import getopt
import math
import os
import random
import sys
import time
from mercurial.node import nullrev
from mercurial import (
ancestor,
debugcommands,
hg,
pycompat,
ui as uimod,
util,
)
if pycompat.ispy3:
long = int
xrange = range
def buildgraph(rng, nodes=100, rootprob=0.05, mergeprob=0.2, prevprob=0.7):
'''nodes: total number of nodes in the graph
rootprob: probability that a new node (not 0) will be a root
mergeprob: probability that, excluding a root a node will be a merge
prevprob: probability that p1 will be the previous node
return value is a graph represented as an adjacency list.
'''
graph = [None] * nodes
for i in xrange(nodes):
if i == 0 or rng.random() < rootprob:
graph[i] = [nullrev]
elif i == 1:
graph[i] = [0]
elif rng.random() < mergeprob:
if i == 2 or rng.random() < prevprob:
# p1 is prev
p1 = i - 1
else:
p1 = rng.randrange(i - 1)
p2 = rng.choice(list(range(0, p1)) + list(range(p1 + 1, i)))
graph[i] = [p1, p2]
elif rng.random() < prevprob:
graph[i] = [i - 1]
else:
graph[i] = [rng.randrange(i - 1)]
return graph
def buildancestorsets(graph):
ancs = [None] * len(graph)
for i in xrange(len(graph)):
ancs[i] = {i}
if graph[i] == [nullrev]:
continue
for p in graph[i]:
ancs[i].update(ancs[p])
return ancs
class naiveincrementalmissingancestors(object):
def __init__(self, ancs, bases):
self.ancs = ancs
self.bases = set(bases)
def addbases(self, newbases):
self.bases.update(newbases)
def removeancestorsfrom(self, revs):
for base in self.bases:
if base != nullrev:
revs.difference_update(self.ancs[base])
revs.discard(nullrev)
def missingancestors(self, revs):
res = set()
for rev in revs:
if rev != nullrev:
res.update(self.ancs[rev])
for base in self.bases:
if base != nullrev:
res.difference_update(self.ancs[base])
return sorted(res)
def test_missingancestors(seed, rng):
# empirically observed to take around 1 second
graphcount = 100
testcount = 10
inccount = 10
nerrs = [0]
# the default mu and sigma give us a nice distribution of mostly
# single-digit counts (including 0) with some higher ones
def lognormrandom(mu, sigma):
return int(math.floor(rng.lognormvariate(mu, sigma)))
def samplerevs(nodes, mu=1.1, sigma=0.8):
count = min(lognormrandom(mu, sigma), len(nodes))
return rng.sample(nodes, count)
def err(seed, graph, bases, seq, output, expected):
if nerrs[0] == 0:
print('seed:', hex(seed)[:-1], file=sys.stderr)
if gerrs[0] == 0:
print('graph:', graph, file=sys.stderr)
print('* bases:', bases, file=sys.stderr)
print('* seq: ', seq, file=sys.stderr)
print('* output: ', output, file=sys.stderr)
print('* expected:', expected, file=sys.stderr)
nerrs[0] += 1
gerrs[0] += 1
for g in xrange(graphcount):
graph = buildgraph(rng)
ancs = buildancestorsets(graph)
gerrs = [0]
for _ in xrange(testcount):
# start from nullrev to include it as a possibility
graphnodes = range(nullrev, len(graph))
bases = samplerevs(graphnodes)
# fast algorithm
inc = ancestor.incrementalmissingancestors(graph.__getitem__, bases)
# reference slow algorithm
naiveinc = naiveincrementalmissingancestors(ancs, bases)
seq = []
revs = []
for _ in xrange(inccount):
if rng.random() < 0.2:
newbases = samplerevs(graphnodes)
seq.append(('addbases', newbases))
inc.addbases(newbases)
naiveinc.addbases(newbases)
if rng.random() < 0.4:
# larger set so that there are more revs to remove from
revs = samplerevs(graphnodes, mu=1.5)
seq.append(('removeancestorsfrom', revs))
hrevs = set(revs)
rrevs = set(revs)
inc.removeancestorsfrom(hrevs)
naiveinc.removeancestorsfrom(rrevs)
if hrevs != rrevs:
err(seed, graph, bases, seq, sorted(hrevs),
sorted(rrevs))
else:
revs = samplerevs(graphnodes)
seq.append(('missingancestors', revs))
h = inc.missingancestors(revs)
r = naiveinc.missingancestors(revs)
if h != r:
err(seed, graph, bases, seq, h, r)
# graph is a dict of child->parent adjacency lists for this graph:
# o 13
# |
# | o 12
# | |
# | | o 11
# | | |\
# | | | | o 10
# | | | | |
# | o---+ | 9
# | | | | |
# o | | | | 8
# / / / /
# | | o | 7
# | | | |
# o---+ | 6
# / / /
# | | o 5
# | |/
# | o 4
# | |
# o | 3
# | |
# | o 2
# |/
# o 1
# |
# o 0
graph = {0: [-1, -1], 1: [0, -1], 2: [1, -1], 3: [1, -1], 4: [2, -1],
5: [4, -1], 6: [4, -1], 7: [4, -1], 8: [-1, -1], 9: [6, 7],
10: [5, -1], 11: [3, 7], 12: [9, -1], 13: [8, -1]}
def genlazyancestors(revs, stoprev=0, inclusive=False):
print(("%% lazy ancestor set for %s, stoprev = %s, inclusive = %s" %
(revs, stoprev, inclusive)))
return ancestor.lazyancestors(graph.get, revs, stoprev=stoprev,
inclusive=inclusive)
def printlazyancestors(s, l):
print('membership: %r' % [n for n in l if n in s])
print('iteration: %r' % list(s))
def test_lazyancestors():
# Empty revs
s = genlazyancestors([])
printlazyancestors(s, [3, 0, -1])
# Standard example
s = genlazyancestors([11, 13])
printlazyancestors(s, [11, 13, 7, 9, 8, 3, 6, 4, 1, -1, 0])
# Standard with ancestry in the initial set (1 is ancestor of 3)
s = genlazyancestors([1, 3])
printlazyancestors(s, [1, -1, 0])
# Including revs
s = genlazyancestors([11, 13], inclusive=True)
printlazyancestors(s, [11, 13, 7, 9, 8, 3, 6, 4, 1, -1, 0])
# Test with stoprev
s = genlazyancestors([11, 13], stoprev=6)
printlazyancestors(s, [11, 13, 7, 9, 8, 3, 6, 4, 1, -1, 0])
s = genlazyancestors([11, 13], stoprev=6, inclusive=True)
printlazyancestors(s, [11, 13, 7, 9, 8, 3, 6, 4, 1, -1, 0])
# Test with stoprev >= min(initrevs)
s = genlazyancestors([11, 13], stoprev=11, inclusive=True)
printlazyancestors(s, [11, 13, 7, 9, 8, 3, 6, 4, 1, -1, 0])
s = genlazyancestors([11, 13], stoprev=12, inclusive=True)
printlazyancestors(s, [11, 13, 7, 9, 8, 3, 6, 4, 1, -1, 0])
# Contiguous chains: 5->4, 2->1 (where 1 is in seen set), 1->0
s = genlazyancestors([10, 1], inclusive=True)
printlazyancestors(s, [2, 10, 4, 5, -1, 0, 1])
# The C gca algorithm requires a real repo. These are textual descriptions of
# DAGs that have been known to be problematic, and, optionally, known pairs
# of revisions and their expected ancestor list.
dagtests = [
(b'+2*2*2/*3/2', {}),
(b'+3*3/*2*2/*4*4/*4/2*4/2*2', {}),
(b'+2*2*/2*4*/4*/3*2/4', {(6, 7): [3, 5]}),
]
def test_gca():
u = uimod.ui.load()
for i, (dag, tests) in enumerate(dagtests):
repo = hg.repository(u, b'gca%d' % i, create=1)
cl = repo.changelog
if not util.safehasattr(cl.index, 'ancestors'):
# C version not available
return
debugcommands.debugbuilddag(u, repo, dag)
# Compare the results of the Python and C versions. This does not
# include choosing a winner when more than one gca exists -- we make
# sure both return exactly the same set of gcas.
# Also compare against expected results, if available.
for a in cl:
for b in cl:
cgcas = sorted(cl.index.ancestors(a, b))
pygcas = sorted(ancestor.ancestors(cl.parentrevs, a, b))
expected = None
if (a, b) in tests:
expected = tests[(a, b)]
if cgcas != pygcas or (expected and cgcas != expected):
print("test_gca: for dag %s, gcas for %d, %d:"
% (dag, a, b))
print(" C returned: %s" % cgcas)
print(" Python returned: %s" % pygcas)
if expected:
print(" expected: %s" % expected)
def main():
seed = None
opts, args = getopt.getopt(sys.argv[1:], 's:', ['seed='])
for o, a in opts:
if o in ('-s', '--seed'):
seed = long(a, base=0) # accepts base 10 or 16 strings
if seed is None:
try:
seed = long(binascii.hexlify(os.urandom(16)), 16)
except AttributeError:
seed = long(time.time() * 1000)
rng = random.Random(seed)
test_missingancestors(seed, rng)
test_lazyancestors()
test_gca()
if __name__ == '__main__':
main()