rust-index: optimize find_gca_candidates() on less than 8 revisions
This is expected to be by far the most common case, given that, e.g.,
merging involves using it on two revisions.
Using a `u8` as support for the bitset obviously divides the amount of
RAM needed by 8. To state the obvious, on a repository with 10 million
changesets, this spares 70MB. It is also possible that it'd be slightly
faster, because it is easier to allocate and provides better cache locality.
It is possible that some exhaustive listing of the traits implemented by
`u8` and `u64` would avoid the added duplication, but that can be done later
and would need a replacement for the `MAX` consts.
from mercurial.node import (
hex,
sha1nodeconstants,
)
from . import (
basestore,
shallowutil,
)
class unionmetadatastore(basestore.baseunionstore):
def __init__(self, *args, **kwargs):
super(unionmetadatastore, self).__init__(*args, **kwargs)
self.stores = args
self.writestore = kwargs.get('writestore')
# If allowincomplete==True then the union store can return partial
# ancestor lists, otherwise it will throw a KeyError if a full
# history can't be found.
self.allowincomplete = kwargs.get('allowincomplete', False)
def getancestors(self, name, node, known=None):
"""Returns as many ancestors as we're aware of.
return value: {
node: (p1, p2, linknode, copyfrom),
...
}
"""
if known is None:
known = set()
if node in known:
return []
ancestors = {}
def traverse(curname, curnode):
# TODO: this algorithm has the potential to traverse parts of
# history twice. Ex: with A->B->C->F and A->B->D->F, both D and C
# may be queued as missing, then B and A are traversed for both.
queue = [(curname, curnode)]
missing = []
seen = set()
while queue:
name, node = queue.pop()
if (name, node) in seen:
continue
seen.add((name, node))
value = ancestors.get(node)
if not value:
missing.append((name, node))
continue
p1, p2, linknode, copyfrom = value
if p1 != sha1nodeconstants.nullid and p1 not in known:
queue.append((copyfrom or curname, p1))
if p2 != sha1nodeconstants.nullid and p2 not in known:
queue.append((curname, p2))
return missing
missing = [(name, node)]
while missing:
curname, curnode = missing.pop()
try:
ancestors.update(
self._getpartialancestors(curname, curnode, known=known)
)
newmissing = traverse(curname, curnode)
missing.extend(newmissing)
except KeyError:
# If we allow incomplete histories, don't throw.
if not self.allowincomplete:
raise
# If the requested name+node doesn't exist, always throw.
if (curname, curnode) == (name, node):
raise
# TODO: ancestors should probably be (name, node) -> (value)
return ancestors
@basestore.baseunionstore.retriable
def _getpartialancestors(self, name, node, known=None):
for store in self.stores:
try:
return store.getancestors(name, node, known=known)
except KeyError:
pass
raise KeyError((name, hex(node)))
@basestore.baseunionstore.retriable
def getnodeinfo(self, name, node):
for store in self.stores:
try:
return store.getnodeinfo(name, node)
except KeyError:
pass
raise KeyError((name, hex(node)))
def add(self, name, node, data):
raise RuntimeError(
b"cannot add content only to remotefilelog contentstore"
)
def getmissing(self, keys):
missing = keys
for store in self.stores:
if missing:
missing = store.getmissing(missing)
return missing
def markledger(self, ledger, options=None):
for store in self.stores:
store.markledger(ledger, options)
def getmetrics(self):
metrics = [s.getmetrics() for s in self.stores]
return shallowutil.sumdicts(*metrics)
class remotefilelogmetadatastore(basestore.basestore):
def getancestors(self, name, node, known=None):
"""Returns as many ancestors as we're aware of.
return value: {
node: (p1, p2, linknode, copyfrom),
...
}
"""
data = self._getdata(name, node)
ancestors = shallowutil.ancestormap(data)
return ancestors
def getnodeinfo(self, name, node):
return self.getancestors(name, node)[node]
def add(self, name, node, parents, linknode):
raise RuntimeError(
b"cannot add metadata only to remotefilelog metadatastore"
)
class remotemetadatastore:
def __init__(self, ui, fileservice, shared):
self._fileservice = fileservice
self._shared = shared
def getancestors(self, name, node, known=None):
self._fileservice.prefetch(
[(name, hex(node))], force=True, fetchdata=False, fetchhistory=True
)
return self._shared.getancestors(name, node, known=known)
def getnodeinfo(self, name, node):
return self.getancestors(name, node)[node]
def add(self, name, node, data):
raise RuntimeError(b"cannot add to a remote store")
def getmissing(self, keys):
return keys
def markledger(self, ledger, options=None):
pass