##// END OF EJS Templates
wireproto: add streams to frame-based protocol...
wireproto: add streams to frame-based protocol Previously, the frame-based protocol was just a series of frames, with each frame associated with a request ID. In order to scale the protocol, we'll want to enable the use of compression. While it is possible to enable compression at the socket/pipe level, this has its disadvantages. The big one is it undermines the point of frames being standalone, atomic units that can be read and written: if you add compression above the framing protocol, you are back to having a stream-based protocol as opposed to something frame-based. So in order to preserve frames, compression needs to occur at the frame payload level. Compressing each frame's payload individually will limit compression ratios because the window size of the compressor will be limited by the max frame size, which is 32-64kb as currently defined. It will also add CPU overhead, as it is more efficient for compressors to operate on fewer, larger blocks of data than more, smaller blocks. So compressing each frame independently is out. This means we need to compress each frame's payload as if it is part of a larger stream. The simplest approach is to have 1 stream per connection. This could certainly work. However, it has disadvantages (documented below). We could also have 1 stream per RPC/command invocation. (This is the model HTTP/2 goes with.) This also has disadvantages. The main disadvantage to one global stream is that it has the very real potential to create CPU bottlenecks doing compression. Networks are only getting faster and the performance of single CPU cores has been relatively flat. Newer compression formats like zstandard offer better CPU cycle efficiency than predecessors like zlib. But it still all too common to saturate your CPU with compression overhead long before you saturate the network pipe. The main disadvantage with streams per request is that you can't reap the benefits of the compression context for multiple requests. For example, if you send 1000 RPC requests (or HTTP/2 requests for that matter), the response to each would have its own compression context. The overall size of the raw responses would be larger because compression contexts wouldn't be able to reference data from another request or response. The approach for streams as implemented in this commit is to support N streams per connection and for streams to potentially span requests and responses. As explained by the added internals docs, this facilitates servers and clients delegating independent streams and compression to independent threads / CPU cores. This helps alleviate the CPU bottleneck of compression. This design also allows compression contexts to be reused across requests/responses. This can result in improved compression ratios and less overhead for compressors and decompressors having to build new contexts. Another feature that was defined was the ability for individual frames within a stream to declare whether that individual frame's payload uses the content encoding (read: compression) defined by the stream. The idea here is that some servers may serve data from a combination of caches and dynamic resolution. Data coming from caches may be pre-compressed. We want to facilitate servers being able to essentially stream bytes from caches to the wire with minimal overhead. Being able to mix and match with frames are compressed within a stream enables these types of advanced server functionality. This commit defines the new streams mechanism. Basic code for supporting streams in frames has been added. But that code is seriously lacking and doesn't fully conform to the defined protocol. For example, we don't close any streams. And support for content encoding within streams is not yet implemented. The change was rather invasive and I didn't think it would be reasonable to implement the entire feature in a single commit. For the record, I would have loved to reuse an existing multiplexing protocol to build the new wire protocol on top of. However, I couldn't find a protocol that offers the performance and scaling characteristics that I desired. Namely, it should support multiple compression contexts to facilitate scaling out to multiple CPU cores and compression contexts should be able to live longer than single RPC requests. HTTP/2 *almost* fits the bill. But the semantics of HTTP message exchange state that streams can only live for a single request-response. We /could/ tunnel on top of HTTP/2 streams and frames with HEADER and DATA frames. But there's no guarantee that HTTP/2 libraries and proxies would allow us to use HTTP/2 streams and frames without the HTTP message exchange semantics defined in RFC 7540 Section 8. Other RPC protocols like gRPC tunnel are built on top of HTTP/2 and thus preserve its semantics of stream per RPC invocation. Even QUIC does this. We could attempt to invent a higher-level stream that spans HTTP/2 streams. But this would be violating HTTP/2 because there is no guarantee that HTTP/2 streams are routed to the same server. The best we can do - which is what this protocol does - is shoehorn all request and response data into a single HTTP message and create streams within. At that point, we've defined a Content-Type in HTTP parlance. It just so happens our media type can also work as a standalone, stream-based protocol, without leaning on HTTP or similar protocol. Differential Revision: https://phab.mercurial-scm.org/D2907

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fileset.py
662 lines | 20.3 KiB | text/x-python | PythonLexer
# fileset.py - file set queries for mercurial
#
# Copyright 2010 Matt Mackall <mpm@selenic.com>
#
# 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 re
from .i18n import _
from . import (
error,
match as matchmod,
merge,
parser,
pycompat,
registrar,
scmutil,
util,
)
from .utils import (
stringutil,
)
elements = {
# token-type: binding-strength, primary, prefix, infix, suffix
"(": (20, None, ("group", 1, ")"), ("func", 1, ")"), None),
":": (15, None, None, ("kindpat", 15), None),
"-": (5, None, ("negate", 19), ("minus", 5), None),
"not": (10, None, ("not", 10), None, None),
"!": (10, None, ("not", 10), None, None),
"and": (5, None, None, ("and", 5), None),
"&": (5, None, None, ("and", 5), None),
"or": (4, None, None, ("or", 4), None),
"|": (4, None, None, ("or", 4), None),
"+": (4, None, None, ("or", 4), None),
",": (2, None, None, ("list", 2), None),
")": (0, None, None, None, None),
"symbol": (0, "symbol", None, None, None),
"string": (0, "string", None, None, None),
"end": (0, None, None, None, None),
}
keywords = {'and', 'or', 'not'}
globchars = ".*{}[]?/\\_"
def tokenize(program):
pos, l = 0, len(program)
program = pycompat.bytestr(program)
while pos < l:
c = program[pos]
if c.isspace(): # skip inter-token whitespace
pass
elif c in "(),-:|&+!": # handle simple operators
yield (c, None, pos)
elif (c in '"\'' or c == 'r' and
program[pos:pos + 2] in ("r'", 'r"')): # handle quoted strings
if c == 'r':
pos += 1
c = program[pos]
decode = lambda x: x
else:
decode = parser.unescapestr
pos += 1
s = pos
while pos < l: # find closing quote
d = program[pos]
if d == '\\': # skip over escaped characters
pos += 2
continue
if d == c:
yield ('string', decode(program[s:pos]), s)
break
pos += 1
else:
raise error.ParseError(_("unterminated string"), s)
elif c.isalnum() or c in globchars or ord(c) > 127:
# gather up a symbol/keyword
s = pos
pos += 1
while pos < l: # find end of symbol
d = program[pos]
if not (d.isalnum() or d in globchars or ord(d) > 127):
break
pos += 1
sym = program[s:pos]
if sym in keywords: # operator keywords
yield (sym, None, s)
else:
yield ('symbol', sym, s)
pos -= 1
else:
raise error.ParseError(_("syntax error"), pos)
pos += 1
yield ('end', None, pos)
def parse(expr):
p = parser.parser(elements)
tree, pos = p.parse(tokenize(expr))
if pos != len(expr):
raise error.ParseError(_("invalid token"), pos)
return tree
def getsymbol(x):
if x and x[0] == 'symbol':
return x[1]
raise error.ParseError(_('not a symbol'))
def getstring(x, err):
if x and (x[0] == 'string' or x[0] == 'symbol'):
return x[1]
raise error.ParseError(err)
def _getkindpat(x, y, allkinds, err):
kind = getsymbol(x)
pat = getstring(y, err)
if kind not in allkinds:
raise error.ParseError(_("invalid pattern kind: %s") % kind)
return '%s:%s' % (kind, pat)
def getpattern(x, allkinds, err):
if x and x[0] == 'kindpat':
return _getkindpat(x[1], x[2], allkinds, err)
return getstring(x, err)
def getset(mctx, x):
if not x:
raise error.ParseError(_("missing argument"))
return methods[x[0]](mctx, *x[1:])
def stringset(mctx, x):
m = mctx.matcher([x])
return [f for f in mctx.subset if m(f)]
def kindpatset(mctx, x, y):
return stringset(mctx, _getkindpat(x, y, matchmod.allpatternkinds,
_("pattern must be a string")))
def andset(mctx, x, y):
return getset(mctx.narrow(getset(mctx, x)), y)
def orset(mctx, x, y):
# needs optimizing
xl = getset(mctx, x)
yl = getset(mctx, y)
return xl + [f for f in yl if f not in xl]
def notset(mctx, x):
s = set(getset(mctx, x))
return [r for r in mctx.subset if r not in s]
def minusset(mctx, x, y):
xl = getset(mctx, x)
yl = set(getset(mctx, y))
return [f for f in xl if f not in yl]
def negateset(mctx, x):
raise error.ParseError(_("can't use negate operator in this context"))
def listset(mctx, a, b):
raise error.ParseError(_("can't use a list in this context"),
hint=_('see hg help "filesets.x or y"'))
# symbols are callable like:
# fun(mctx, x)
# with:
# mctx - current matchctx instance
# x - argument in tree form
symbols = {}
# filesets using matchctx.status()
_statuscallers = set()
# filesets using matchctx.existing()
_existingcallers = set()
predicate = registrar.filesetpredicate()
@predicate('modified()', callstatus=True)
def modified(mctx, x):
"""File that is modified according to :hg:`status`.
"""
# i18n: "modified" is a keyword
getargs(x, 0, 0, _("modified takes no arguments"))
s = set(mctx.status().modified)
return [f for f in mctx.subset if f in s]
@predicate('added()', callstatus=True)
def added(mctx, x):
"""File that is added according to :hg:`status`.
"""
# i18n: "added" is a keyword
getargs(x, 0, 0, _("added takes no arguments"))
s = set(mctx.status().added)
return [f for f in mctx.subset if f in s]
@predicate('removed()', callstatus=True)
def removed(mctx, x):
"""File that is removed according to :hg:`status`.
"""
# i18n: "removed" is a keyword
getargs(x, 0, 0, _("removed takes no arguments"))
s = set(mctx.status().removed)
return [f for f in mctx.subset if f in s]
@predicate('deleted()', callstatus=True)
def deleted(mctx, x):
"""Alias for ``missing()``.
"""
# i18n: "deleted" is a keyword
getargs(x, 0, 0, _("deleted takes no arguments"))
s = set(mctx.status().deleted)
return [f for f in mctx.subset if f in s]
@predicate('missing()', callstatus=True)
def missing(mctx, x):
"""File that is missing according to :hg:`status`.
"""
# i18n: "missing" is a keyword
getargs(x, 0, 0, _("missing takes no arguments"))
s = set(mctx.status().deleted)
return [f for f in mctx.subset if f in s]
@predicate('unknown()', callstatus=True)
def unknown(mctx, x):
"""File that is unknown according to :hg:`status`. These files will only be
considered if this predicate is used.
"""
# i18n: "unknown" is a keyword
getargs(x, 0, 0, _("unknown takes no arguments"))
s = set(mctx.status().unknown)
return [f for f in mctx.subset if f in s]
@predicate('ignored()', callstatus=True)
def ignored(mctx, x):
"""File that is ignored according to :hg:`status`. These files will only be
considered if this predicate is used.
"""
# i18n: "ignored" is a keyword
getargs(x, 0, 0, _("ignored takes no arguments"))
s = set(mctx.status().ignored)
return [f for f in mctx.subset if f in s]
@predicate('clean()', callstatus=True)
def clean(mctx, x):
"""File that is clean according to :hg:`status`.
"""
# i18n: "clean" is a keyword
getargs(x, 0, 0, _("clean takes no arguments"))
s = set(mctx.status().clean)
return [f for f in mctx.subset if f in s]
def func(mctx, a, b):
funcname = getsymbol(a)
if funcname in symbols:
enabled = mctx._existingenabled
mctx._existingenabled = funcname in _existingcallers
try:
return symbols[funcname](mctx, b)
finally:
mctx._existingenabled = enabled
keep = lambda fn: getattr(fn, '__doc__', None) is not None
syms = [s for (s, fn) in symbols.items() if keep(fn)]
raise error.UnknownIdentifier(funcname, syms)
def getlist(x):
if not x:
return []
if x[0] == 'list':
return getlist(x[1]) + [x[2]]
return [x]
def getargs(x, min, max, err):
l = getlist(x)
if len(l) < min or len(l) > max:
raise error.ParseError(err)
return l
@predicate('binary()', callexisting=True)
def binary(mctx, x):
"""File that appears to be binary (contains NUL bytes).
"""
# i18n: "binary" is a keyword
getargs(x, 0, 0, _("binary takes no arguments"))
return [f for f in mctx.existing() if mctx.ctx[f].isbinary()]
@predicate('exec()', callexisting=True)
def exec_(mctx, x):
"""File that is marked as executable.
"""
# i18n: "exec" is a keyword
getargs(x, 0, 0, _("exec takes no arguments"))
return [f for f in mctx.existing() if mctx.ctx.flags(f) == 'x']
@predicate('symlink()', callexisting=True)
def symlink(mctx, x):
"""File that is marked as a symlink.
"""
# i18n: "symlink" is a keyword
getargs(x, 0, 0, _("symlink takes no arguments"))
return [f for f in mctx.existing() if mctx.ctx.flags(f) == 'l']
@predicate('resolved()')
def resolved(mctx, x):
"""File that is marked resolved according to :hg:`resolve -l`.
"""
# i18n: "resolved" is a keyword
getargs(x, 0, 0, _("resolved takes no arguments"))
if mctx.ctx.rev() is not None:
return []
ms = merge.mergestate.read(mctx.ctx.repo())
return [f for f in mctx.subset if f in ms and ms[f] == 'r']
@predicate('unresolved()')
def unresolved(mctx, x):
"""File that is marked unresolved according to :hg:`resolve -l`.
"""
# i18n: "unresolved" is a keyword
getargs(x, 0, 0, _("unresolved takes no arguments"))
if mctx.ctx.rev() is not None:
return []
ms = merge.mergestate.read(mctx.ctx.repo())
return [f for f in mctx.subset if f in ms and ms[f] == 'u']
@predicate('hgignore()')
def hgignore(mctx, x):
"""File that matches the active .hgignore pattern.
"""
# i18n: "hgignore" is a keyword
getargs(x, 0, 0, _("hgignore takes no arguments"))
ignore = mctx.ctx.repo().dirstate._ignore
return [f for f in mctx.subset if ignore(f)]
@predicate('portable()')
def portable(mctx, x):
"""File that has a portable name. (This doesn't include filenames with case
collisions.)
"""
# i18n: "portable" is a keyword
getargs(x, 0, 0, _("portable takes no arguments"))
checkwinfilename = util.checkwinfilename
return [f for f in mctx.subset if checkwinfilename(f) is None]
@predicate('grep(regex)', callexisting=True)
def grep(mctx, x):
"""File contains the given regular expression.
"""
try:
# i18n: "grep" is a keyword
r = re.compile(getstring(x, _("grep requires a pattern")))
except re.error as e:
raise error.ParseError(_('invalid match pattern: %s') % e)
return [f for f in mctx.existing() if r.search(mctx.ctx[f].data())]
def _sizetomax(s):
try:
s = s.strip().lower()
for k, v in util._sizeunits:
if s.endswith(k):
# max(4k) = 5k - 1, max(4.5k) = 4.6k - 1
n = s[:-len(k)]
inc = 1.0
if "." in n:
inc /= 10 ** len(n.split(".")[1])
return int((float(n) + inc) * v) - 1
# no extension, this is a precise value
return int(s)
except ValueError:
raise error.ParseError(_("couldn't parse size: %s") % s)
def sizematcher(x):
"""Return a function(size) -> bool from the ``size()`` expression"""
# i18n: "size" is a keyword
expr = getstring(x, _("size requires an expression")).strip()
if '-' in expr: # do we have a range?
a, b = expr.split('-', 1)
a = util.sizetoint(a)
b = util.sizetoint(b)
return lambda x: x >= a and x <= b
elif expr.startswith("<="):
a = util.sizetoint(expr[2:])
return lambda x: x <= a
elif expr.startswith("<"):
a = util.sizetoint(expr[1:])
return lambda x: x < a
elif expr.startswith(">="):
a = util.sizetoint(expr[2:])
return lambda x: x >= a
elif expr.startswith(">"):
a = util.sizetoint(expr[1:])
return lambda x: x > a
else:
a = util.sizetoint(expr)
b = _sizetomax(expr)
return lambda x: x >= a and x <= b
@predicate('size(expression)', callexisting=True)
def size(mctx, x):
"""File size matches the given expression. Examples:
- size('1k') - files from 1024 to 2047 bytes
- size('< 20k') - files less than 20480 bytes
- size('>= .5MB') - files at least 524288 bytes
- size('4k - 1MB') - files from 4096 bytes to 1048576 bytes
"""
m = sizematcher(x)
return [f for f in mctx.existing() if m(mctx.ctx[f].size())]
@predicate('encoding(name)', callexisting=True)
def encoding(mctx, x):
"""File can be successfully decoded with the given character
encoding. May not be useful for encodings other than ASCII and
UTF-8.
"""
# i18n: "encoding" is a keyword
enc = getstring(x, _("encoding requires an encoding name"))
s = []
for f in mctx.existing():
d = mctx.ctx[f].data()
try:
d.decode(enc)
except LookupError:
raise error.Abort(_("unknown encoding '%s'") % enc)
except UnicodeDecodeError:
continue
s.append(f)
return s
@predicate('eol(style)', callexisting=True)
def eol(mctx, x):
"""File contains newlines of the given style (dos, unix, mac). Binary
files are excluded, files with mixed line endings match multiple
styles.
"""
# i18n: "eol" is a keyword
enc = getstring(x, _("eol requires a style name"))
s = []
for f in mctx.existing():
d = mctx.ctx[f].data()
if stringutil.binary(d):
continue
if (enc == 'dos' or enc == 'win') and '\r\n' in d:
s.append(f)
elif enc == 'unix' and re.search('(?<!\r)\n', d):
s.append(f)
elif enc == 'mac' and re.search('\r(?!\n)', d):
s.append(f)
return s
@predicate('copied()')
def copied(mctx, x):
"""File that is recorded as being copied.
"""
# i18n: "copied" is a keyword
getargs(x, 0, 0, _("copied takes no arguments"))
s = []
for f in mctx.subset:
if f in mctx.ctx:
p = mctx.ctx[f].parents()
if p and p[0].path() != f:
s.append(f)
return s
@predicate('revs(revs, pattern)')
def revs(mctx, x):
"""Evaluate set in the specified revisions. If the revset match multiple
revs, this will return file matching pattern in any of the revision.
"""
# i18n: "revs" is a keyword
r, x = getargs(x, 2, 2, _("revs takes two arguments"))
# i18n: "revs" is a keyword
revspec = getstring(r, _("first argument to revs must be a revision"))
repo = mctx.ctx.repo()
revs = scmutil.revrange(repo, [revspec])
found = set()
result = []
for r in revs:
ctx = repo[r]
for f in getset(mctx.switch(ctx, _buildstatus(ctx, x)), x):
if f not in found:
found.add(f)
result.append(f)
return result
@predicate('status(base, rev, pattern)')
def status(mctx, x):
"""Evaluate predicate using status change between ``base`` and
``rev``. Examples:
- ``status(3, 7, added())`` - matches files added from "3" to "7"
"""
repo = mctx.ctx.repo()
# i18n: "status" is a keyword
b, r, x = getargs(x, 3, 3, _("status takes three arguments"))
# i18n: "status" is a keyword
baseerr = _("first argument to status must be a revision")
baserevspec = getstring(b, baseerr)
if not baserevspec:
raise error.ParseError(baseerr)
reverr = _("second argument to status must be a revision")
revspec = getstring(r, reverr)
if not revspec:
raise error.ParseError(reverr)
basectx, ctx = scmutil.revpair(repo, [baserevspec, revspec])
return getset(mctx.switch(ctx, _buildstatus(ctx, x, basectx=basectx)), x)
@predicate('subrepo([pattern])')
def subrepo(mctx, x):
"""Subrepositories whose paths match the given pattern.
"""
# i18n: "subrepo" is a keyword
getargs(x, 0, 1, _("subrepo takes at most one argument"))
ctx = mctx.ctx
sstate = sorted(ctx.substate)
if x:
pat = getpattern(x, matchmod.allpatternkinds,
# i18n: "subrepo" is a keyword
_("subrepo requires a pattern or no arguments"))
fast = not matchmod.patkind(pat)
if fast:
def m(s):
return (s == pat)
else:
m = matchmod.match(ctx.repo().root, '', [pat], ctx=ctx)
return [sub for sub in sstate if m(sub)]
else:
return [sub for sub in sstate]
methods = {
'string': stringset,
'symbol': stringset,
'kindpat': kindpatset,
'and': andset,
'or': orset,
'minus': minusset,
'negate': negateset,
'list': listset,
'group': getset,
'not': notset,
'func': func,
}
class matchctx(object):
def __init__(self, ctx, subset, status=None):
self.ctx = ctx
self.subset = subset
self._status = status
self._existingenabled = False
def status(self):
return self._status
def matcher(self, patterns):
return self.ctx.match(patterns)
def filter(self, files):
return [f for f in files if f in self.subset]
def existing(self):
assert self._existingenabled, 'unexpected existing() invocation'
if self._status is not None:
removed = set(self._status[3])
unknown = set(self._status[4] + self._status[5])
else:
removed = set()
unknown = set()
return (f for f in self.subset
if (f in self.ctx and f not in removed) or f in unknown)
def narrow(self, files):
return matchctx(self.ctx, self.filter(files), self._status)
def switch(self, ctx, status=None):
subset = self.filter(_buildsubset(ctx, status))
return matchctx(ctx, subset, status)
class fullmatchctx(matchctx):
"""A match context where any files in any revisions should be valid"""
def __init__(self, ctx, status=None):
subset = _buildsubset(ctx, status)
super(fullmatchctx, self).__init__(ctx, subset, status)
def switch(self, ctx, status=None):
return fullmatchctx(ctx, status)
# filesets using matchctx.switch()
_switchcallers = [
'revs',
'status',
]
def _intree(funcs, tree):
if isinstance(tree, tuple):
if tree[0] == 'func' and tree[1][0] == 'symbol':
if tree[1][1] in funcs:
return True
if tree[1][1] in _switchcallers:
# arguments won't be evaluated in the current context
return False
for s in tree[1:]:
if _intree(funcs, s):
return True
return False
def _buildsubset(ctx, status):
if status:
subset = []
for c in status:
subset.extend(c)
return subset
else:
return list(ctx.walk(ctx.match([])))
def getfileset(ctx, expr):
tree = parse(expr)
return getset(fullmatchctx(ctx, _buildstatus(ctx, tree)), tree)
def _buildstatus(ctx, tree, basectx=None):
# do we need status info?
# temporaty boolean to simplify the next conditional
purewdir = ctx.rev() is None and basectx is None
if (_intree(_statuscallers, tree) or
# Using matchctx.existing() on a workingctx requires us to check
# for deleted files.
(purewdir and _intree(_existingcallers, tree))):
unknown = _intree(['unknown'], tree)
ignored = _intree(['ignored'], tree)
r = ctx.repo()
if basectx is None:
basectx = ctx.p1()
return r.status(basectx, ctx,
unknown=unknown, ignored=ignored, clean=True)
else:
return None
def prettyformat(tree):
return parser.prettyformat(tree, ('string', 'symbol'))
def loadpredicate(ui, extname, registrarobj):
"""Load fileset predicates from specified registrarobj
"""
for name, func in registrarobj._table.iteritems():
symbols[name] = func
if func._callstatus:
_statuscallers.add(name)
if func._callexisting:
_existingcallers.add(name)
# load built-in predicates explicitly to setup _statuscallers/_existingcallers
loadpredicate(None, None, predicate)
# tell hggettext to extract docstrings from these functions:
i18nfunctions = symbols.values()