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localrepo: iteratively derive local repository type...
localrepo: iteratively derive local repository type This commit implements the dynamic local repository type derivation that was explained in the recent commit bfeab472e3c0 "localrepo: create new function for instantiating a local repo object." Instead of a static localrepository class/type which must be customized after construction, we now dynamically construct a type by building up base classes/types to represent specific repository interfaces. Conceptually, the end state is similar to what was happening when various extensions would monkeypatch the __class__ of newly-constructed repo instances. However, the approach is inverted. Instead of making the instance then customizing it, we do the customization up front by influencing the behavior of the type then we instantiate that custom type. This approach gives us much more flexibility. For example, we can use completely separate classes for implementing different aspects of the repository. For example, we could have one class representing revlog-based file storage and another representing non-revlog based file storage. When then choose which implementation to use based on the presence of repo requirements. A concern with this approach is that it creates a lot more types and complexity and that complexity adds overhead. Yes, it is true that this approach will result in more types being created. Yes, this is more complicated than traditional "instantiate a static type." However, I believe the alternatives to supporting alternate storage backends are just as complicated. (Before I arrived at this solution, I had patches storing factory functions on local repo instances for e.g. constructing a file storage instance. We ended up having a handful of these. And this was logically identical to assigning custom methods. Since we were logically changing the type of the instance, I figured it would be better to just use specialized types instead of introducing levels of abstraction at run-time.) On the performance front, I don't believe that having N base classes has any significant performance overhead compared to just a single base class. Intuition says that Python will need to iterate the base classes to find an attribute. However, CPython caches method lookups: as long as the __class__ or MRO isn't changing, method attribute lookup should be constant time after first access. And non-method attributes are stored in __dict__, of which there is only 1 per object, so the number of base classes for __dict__ is irrelevant. Anyway, this commit splits up the monolithic completelocalrepository interface into sub-interfaces: 1 for file storage and 1 representing everything else. We've taught ``makelocalrepository()`` to call a series of factory functions which will produce types implementing specific interfaces. It then calls type() to create a new type from the built-up list of base types. This commit should be considered a start and not the end state. I suspect we'll hit a number of problems as we start to implement alternate storage backends: * Passing custom arguments to __init__ and setting custom attributes on __dict__. * Customizing the set of interfaces that are needed. e.g. the "readonly" intent could translate to not requesting an interface providing methods related to writing. * More ergonomic way for extensions to insert themselves so their callbacks aren't unconditionally called. * Wanting to modify vfs instances, other arguments passed to __init__. That being said, this code is usable in its current state and I'm convinced future commits will demonstrate the value in this approach. Differential Revision: https://phab.mercurial-scm.org/D4642

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p4.py
378 lines | 12.4 KiB | text/x-python | PythonLexer
# Perforce source for convert extension.
#
# Copyright 2009, Frank Kingswood <frank@kingswood-consulting.co.uk>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
import marshal
import re
from mercurial.i18n import _
from mercurial import (
error,
util,
)
from mercurial.utils import (
dateutil,
procutil,
stringutil,
)
from . import common
def loaditer(f):
"Yield the dictionary objects generated by p4"
try:
while True:
d = marshal.load(f)
if not d:
break
yield d
except EOFError:
pass
def decodefilename(filename):
"""Perforce escapes special characters @, #, *, or %
with %40, %23, %2A, or %25 respectively
>>> decodefilename(b'portable-net45%252Bnetcore45%252Bwp8%252BMonoAndroid')
'portable-net45%2Bnetcore45%2Bwp8%2BMonoAndroid'
>>> decodefilename(b'//Depot/Directory/%2525/%2523/%23%40.%2A')
'//Depot/Directory/%25/%23/#@.*'
"""
replacements = [('%2A', '*'), ('%23', '#'), ('%40', '@'), ('%25', '%')]
for k, v in replacements:
filename = filename.replace(k, v)
return filename
class p4_source(common.converter_source):
def __init__(self, ui, repotype, path, revs=None):
# avoid import cycle
from . import convcmd
super(p4_source, self).__init__(ui, repotype, path, revs=revs)
if "/" in path and not path.startswith('//'):
raise common.NoRepo(_('%s does not look like a P4 repository') %
path)
common.checktool('p4', abort=False)
self.revmap = {}
self.encoding = self.ui.config('convert', 'p4.encoding',
convcmd.orig_encoding)
self.re_type = re.compile(
"([a-z]+)?(text|binary|symlink|apple|resource|unicode|utf\d+)"
"(\+\w+)?$")
self.re_keywords = re.compile(
r"\$(Id|Header|Date|DateTime|Change|File|Revision|Author)"
r":[^$\n]*\$")
self.re_keywords_old = re.compile("\$(Id|Header):[^$\n]*\$")
if revs and len(revs) > 1:
raise error.Abort(_("p4 source does not support specifying "
"multiple revisions"))
def setrevmap(self, revmap):
"""Sets the parsed revmap dictionary.
Revmap stores mappings from a source revision to a target revision.
It is set in convertcmd.convert and provided by the user as a file
on the commandline.
Revisions in the map are considered beeing present in the
repository and ignored during _parse(). This allows for incremental
imports if a revmap is provided.
"""
self.revmap = revmap
def _parse_view(self, path):
"Read changes affecting the path"
cmd = 'p4 -G changes -s submitted %s' % procutil.shellquote(path)
stdout = procutil.popen(cmd, mode='rb')
p4changes = {}
for d in loaditer(stdout):
c = d.get("change", None)
if c:
p4changes[c] = True
return p4changes
def _parse(self, ui, path):
"Prepare list of P4 filenames and revisions to import"
p4changes = {}
changeset = {}
files_map = {}
copies_map = {}
localname = {}
depotname = {}
heads = []
ui.status(_('reading p4 views\n'))
# read client spec or view
if "/" in path:
p4changes.update(self._parse_view(path))
if path.startswith("//") and path.endswith("/..."):
views = {path[:-3]:""}
else:
views = {"//": ""}
else:
cmd = 'p4 -G client -o %s' % procutil.shellquote(path)
clientspec = marshal.load(procutil.popen(cmd, mode='rb'))
views = {}
for client in clientspec:
if client.startswith("View"):
sview, cview = clientspec[client].split()
p4changes.update(self._parse_view(sview))
if sview.endswith("...") and cview.endswith("..."):
sview = sview[:-3]
cview = cview[:-3]
cview = cview[2:]
cview = cview[cview.find("/") + 1:]
views[sview] = cview
# list of changes that affect our source files
p4changes = p4changes.keys()
p4changes.sort(key=int)
# list with depot pathnames, longest first
vieworder = views.keys()
vieworder.sort(key=len, reverse=True)
# handle revision limiting
startrev = self.ui.config('convert', 'p4.startrev')
# now read the full changelists to get the list of file revisions
ui.status(_('collecting p4 changelists\n'))
lastid = None
for change in p4changes:
if startrev and int(change) < int(startrev):
continue
if self.revs and int(change) > int(self.revs[0]):
continue
if change in self.revmap:
# Ignore already present revisions, but set the parent pointer.
lastid = change
continue
if lastid:
parents = [lastid]
else:
parents = []
d = self._fetch_revision(change)
c = self._construct_commit(d, parents)
descarr = c.desc.splitlines(True)
if len(descarr) > 0:
shortdesc = descarr[0].rstrip('\r\n')
else:
shortdesc = '**empty changelist description**'
t = '%s %s' % (c.rev, repr(shortdesc)[1:-1])
ui.status(stringutil.ellipsis(t, 80) + '\n')
files = []
copies = {}
copiedfiles = []
i = 0
while ("depotFile%d" % i) in d and ("rev%d" % i) in d:
oldname = d["depotFile%d" % i]
filename = None
for v in vieworder:
if oldname.lower().startswith(v.lower()):
filename = decodefilename(views[v] + oldname[len(v):])
break
if filename:
files.append((filename, d["rev%d" % i]))
depotname[filename] = oldname
if (d.get("action%d" % i) == "move/add"):
copiedfiles.append(filename)
localname[oldname] = filename
i += 1
# Collect information about copied files
for filename in copiedfiles:
oldname = depotname[filename]
flcmd = 'p4 -G filelog %s' \
% procutil.shellquote(oldname)
flstdout = procutil.popen(flcmd, mode='rb')
copiedfilename = None
for d in loaditer(flstdout):
copiedoldname = None
i = 0
while ("change%d" % i) in d:
if (d["change%d" % i] == change and
d["action%d" % i] == "move/add"):
j = 0
while ("file%d,%d" % (i, j)) in d:
if d["how%d,%d" % (i, j)] == "moved from":
copiedoldname = d["file%d,%d" % (i, j)]
break
j += 1
i += 1
if copiedoldname and copiedoldname in localname:
copiedfilename = localname[copiedoldname]
break
if copiedfilename:
copies[filename] = copiedfilename
else:
ui.warn(_("cannot find source for copied file: %s@%s\n")
% (filename, change))
changeset[change] = c
files_map[change] = files
copies_map[change] = copies
lastid = change
if lastid and len(changeset) > 0:
heads = [lastid]
return {
'changeset': changeset,
'files': files_map,
'copies': copies_map,
'heads': heads,
'depotname': depotname,
}
@util.propertycache
def _parse_once(self):
return self._parse(self.ui, self.path)
@util.propertycache
def copies(self):
return self._parse_once['copies']
@util.propertycache
def files(self):
return self._parse_once['files']
@util.propertycache
def changeset(self):
return self._parse_once['changeset']
@util.propertycache
def heads(self):
return self._parse_once['heads']
@util.propertycache
def depotname(self):
return self._parse_once['depotname']
def getheads(self):
return self.heads
def getfile(self, name, rev):
cmd = 'p4 -G print %s' \
% procutil.shellquote("%s#%s" % (self.depotname[name], rev))
lasterror = None
while True:
stdout = procutil.popen(cmd, mode='rb')
mode = None
contents = []
keywords = None
for d in loaditer(stdout):
code = d["code"]
data = d.get("data")
if code == "error":
# if this is the first time error happened
# re-attempt getting the file
if not lasterror:
lasterror = IOError(d["generic"], data)
# this will exit inner-most for-loop
break
else:
raise lasterror
elif code == "stat":
action = d.get("action")
if action in ["purge", "delete", "move/delete"]:
return None, None
p4type = self.re_type.match(d["type"])
if p4type:
mode = ""
flags = ((p4type.group(1) or "")
+ (p4type.group(3) or ""))
if "x" in flags:
mode = "x"
if p4type.group(2) == "symlink":
mode = "l"
if "ko" in flags:
keywords = self.re_keywords_old
elif "k" in flags:
keywords = self.re_keywords
elif code == "text" or code == "binary":
contents.append(data)
lasterror = None
if not lasterror:
break
if mode is None:
return None, None
contents = ''.join(contents)
if keywords:
contents = keywords.sub("$\\1$", contents)
if mode == "l" and contents.endswith("\n"):
contents = contents[:-1]
return contents, mode
def getchanges(self, rev, full):
if full:
raise error.Abort(_("convert from p4 does not support --full"))
return self.files[rev], self.copies[rev], set()
def _construct_commit(self, obj, parents=None):
"""
Constructs a common.commit object from an unmarshalled
`p4 describe` output
"""
desc = self.recode(obj.get("desc", ""))
date = (int(obj["time"]), 0) # timezone not set
if parents is None:
parents = []
return common.commit(author=self.recode(obj["user"]),
date=dateutil.datestr(date, '%Y-%m-%d %H:%M:%S %1%2'),
parents=parents, desc=desc, branch=None, rev=obj['change'],
extra={"p4": obj['change'], "convert_revision": obj['change']})
def _fetch_revision(self, rev):
"""Return an output of `p4 describe` including author, commit date as
a dictionary."""
cmd = "p4 -G describe -s %s" % rev
stdout = procutil.popen(cmd, mode='rb')
return marshal.load(stdout)
def getcommit(self, rev):
if rev in self.changeset:
return self.changeset[rev]
elif rev in self.revmap:
d = self._fetch_revision(rev)
return self._construct_commit(d, parents=None)
raise error.Abort(
_("cannot find %s in the revmap or parsed changesets") % rev)
def gettags(self):
return {}
def getchangedfiles(self, rev, i):
return sorted([x[0] for x in self.files[rev]])