phases: rework the logic of _pushdiscoveryphase to bound complexity
This rework the various graph traversal in _pushdiscoveryphase to keep the
complexity in check.
This is done though a couple of things:
- first, limiting the space we have to explore, for example, if we are not in
publishing push, we don't need to consider remote draft roots that are also
draft locally, as there is nothing to be moved there.
- avoid unbounded descendant computation, and use the faster "rev between"
computation.
This provide a massive boost to performance when exchanging with repository with
a massive amount of draft, like mozilla-try:
### data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog
# benchmark.name = hg.command.push
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.explicit-rev = all-out-heads
# benchmark.variants.issue6528 = disabled
# benchmark.variants.protocol = ssh
# benchmark.variants.reuse-external-delta-parent = default
## benchmark.variants.revs = any-1-extra-rev
before: 20.346590 seconds
after: 11.232059 seconds (-38.15%, -7.48 seconds)
## benchmark.variants.revs = any-100-extra-rev
before: 24.752051 seconds
after: 15.367412 seconds (-37.91%, -9.38 seconds)
After this changes, the push operation is still quite too slow. Some of this
can be attributed to general phases slowness (reading all the roots from disk
for example) and other know slowness (not using persistent-nodemap, branchmap,
tags, etc. We are also working on them, but with this series, phase discovery
during push no longer showing up in profile and this is a pretty nice and bit
low-hanging fruit out of the way.
### (same case as the above)
# benchmark.variants.revs = any-1-extra-rev
pre-%ln-change: 44.235070
this-changeset: 11.232059 seconds (-74.61%, -33.00 seconds)
# benchmark.variants.revs = any-100-extra-rev
pre-%ln-change: 49.234697
this-changeset: 15.367412 seconds (-68.79%, -33.87 seconds)
Note that with this change, the `hg push` performance is now much closer to the
`hg pull` performance, even it still lagging behind a bit. (and the overall
performance are still too slow).
### data-env-vars.name = mozilla-try-2023-03-22-ds2-pnm
# benchmark.variants.explicit-rev = all-out-heads
# benchmark.variants.issue6528 = disabled
# benchmark.variants.protocol = ssh
# benchmark.variants.pulled-delta-reuse-policy = default
# bin-env-vars.hg.flavor = rust
## benchmark.variants.revs = any-1-extra-rev
hg.command.pull: 6.517450
hg.command.push: 11.219888
## benchmark.variants.revs = any-100-extra-rev
hg.command.pull: 10.160991
hg.command.push: 14.251107
### data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.explicit-rev = all-out-heads
# benchmark.variants.issue6528 = disabled
# benchmark.variants.protocol = ssh
# benchmark.variants.pulled-delta-reuse-policy = default
## bin-env-vars.hg.flavor = default
## benchmark.variants.revs = any-1-extra-rev
hg.command.pull: 8.577772
hg.command.push: 11.232059
## bin-env-vars.hg.flavor = default
## benchmark.variants.revs = any-100-extra-rev
hg.command.pull: 13.152976
hg.command.push: 15.367412
## bin-env-vars.hg.flavor = rust
## benchmark.variants.revs = any-1-extra-rev
hg.command.pull: 8.731982
hg.command.push: 11.178751
## bin-env-vars.hg.flavor = rust
## benchmark.variants.revs = any-100-extra-rev
hg.command.pull: 13.184236
hg.command.push: 15.620843
# dagparser.py - parser and generator for concise description of DAGs
#
# Copyright 2010 Peter Arrenbrecht <peter@arrenbrecht.ch>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
import re
import string
from .i18n import _
from . import (
error,
pycompat,
)
from .utils import stringutil
def parsedag(desc):
'''parses a DAG from a concise textual description; generates events
"+n" is a linear run of n nodes based on the current default parent
"." is a single node based on the current default parent
"$" resets the default parent to -1 (implied at the start);
otherwise the default parent is always the last node created
"<p" sets the default parent to the backref p
"*p" is a fork at parent p, where p is a backref
"*p1/p2/.../pn" is a merge of parents p1..pn, where the pi are backrefs
"/p2/.../pn" is a merge of the preceding node and p2..pn
":name" defines a label for the preceding node; labels can be redefined
"@text" emits an annotation event for text
"!command" emits an action event for the current node
"!!my command\n" is like "!", but to the end of the line
"#...\n" is a comment up to the end of the line
Whitespace between the above elements is ignored.
A backref is either
* a number n, which references the node curr-n, where curr is the current
node, or
* the name of a label you placed earlier using ":name", or
* empty to denote the default parent.
All string valued-elements are either strictly alphanumeric, or must
be enclosed in double quotes ("..."), with "\" as escape character.
Generates sequence of
('n', (id, [parentids])) for node creation
('l', (id, labelname)) for labels on nodes
('a', text) for annotations
('c', command) for actions (!)
('C', command) for line actions (!!)
Examples
--------
Example of a complex graph (output not shown for brevity):
>>> len(list(parsedag(b"""
...
... +3 # 3 nodes in linear run
... :forkhere # a label for the last of the 3 nodes from above
... +5 # 5 more nodes on one branch
... :mergethis # label again
... <forkhere # set default parent to labeled fork node
... +10 # 10 more nodes on a parallel branch
... @stable # following nodes will be annotated as "stable"
... +5 # 5 nodes in stable
... !addfile # custom command; could trigger new file in next node
... +2 # two more nodes
... /mergethis # merge last node with labeled node
... +4 # 4 more nodes descending from merge node
...
... """)))
34
Empty list:
>>> list(parsedag(b""))
[]
A simple linear run:
>>> list(parsedag(b"+3"))
[('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))]
Some non-standard ways to define such runs:
>>> list(parsedag(b"+1+2"))
[('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))]
>>> list(parsedag(b"+1*1*"))
[('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))]
>>> list(parsedag(b"*"))
[('n', (0, [-1]))]
>>> list(parsedag(b"..."))
[('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))]
A fork and a join, using numeric back references:
>>> list(parsedag(b"+2*2*/2"))
[('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [0])), ('n', (3, [2, 1]))]
>>> list(parsedag(b"+2<2+1/2"))
[('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [0])), ('n', (3, [2, 1]))]
Placing a label:
>>> list(parsedag(b"+1 :mylabel +1"))
[('n', (0, [-1])), ('l', (0, 'mylabel')), ('n', (1, [0]))]
An empty label (silly, really):
>>> list(parsedag(b"+1:+1"))
[('n', (0, [-1])), ('l', (0, '')), ('n', (1, [0]))]
Fork and join, but with labels instead of numeric back references:
>>> list(parsedag(b"+1:f +1:p2 *f */p2"))
[('n', (0, [-1])), ('l', (0, 'f')), ('n', (1, [0])), ('l', (1, 'p2')),
('n', (2, [0])), ('n', (3, [2, 1]))]
>>> list(parsedag(b"+1:f +1:p2 <f +1 /p2"))
[('n', (0, [-1])), ('l', (0, 'f')), ('n', (1, [0])), ('l', (1, 'p2')),
('n', (2, [0])), ('n', (3, [2, 1]))]
Restarting from the root:
>>> list(parsedag(b"+1 $ +1"))
[('n', (0, [-1])), ('n', (1, [-1]))]
Annotations, which are meant to introduce sticky state for subsequent nodes:
>>> list(parsedag(b"+1 @ann +1"))
[('n', (0, [-1])), ('a', 'ann'), ('n', (1, [0]))]
>>> list(parsedag(b'+1 @"my annotation" +1'))
[('n', (0, [-1])), ('a', 'my annotation'), ('n', (1, [0]))]
Commands, which are meant to operate on the most recently created node:
>>> list(parsedag(b"+1 !cmd +1"))
[('n', (0, [-1])), ('c', 'cmd'), ('n', (1, [0]))]
>>> list(parsedag(b'+1 !"my command" +1'))
[('n', (0, [-1])), ('c', 'my command'), ('n', (1, [0]))]
>>> list(parsedag(b'+1 !!my command line\\n +1'))
[('n', (0, [-1])), ('C', 'my command line'), ('n', (1, [0]))]
Comments, which extend to the end of the line:
>>> list(parsedag(b'+1 # comment\\n+1'))
[('n', (0, [-1])), ('n', (1, [0]))]
Error:
>>> try: list(parsedag(b'+1 bad'))
... except Exception as e: print(pycompat.sysstr(bytes(e)))
invalid character in dag description: bad...
'''
if not desc:
return
# pytype: disable=wrong-arg-types
wordchars = pycompat.bytestr(string.ascii_letters + string.digits)
# pytype: enable=wrong-arg-types
labels = {}
p1 = -1
r = 0
def resolve(ref):
if not ref:
return p1
# pytype: disable=wrong-arg-types
elif ref[0] in pycompat.bytestr(string.digits):
# pytype: enable=wrong-arg-types
return r - int(ref)
else:
return labels[ref]
chiter = pycompat.iterbytestr(desc)
def nextch():
return next(chiter, b'\0')
def nextrun(c, allow):
s = b''
while c in allow:
s += c
c = nextch()
return c, s
def nextdelimited(c, limit, escape):
s = b''
while c != limit:
if c == escape:
c = nextch()
s += c
c = nextch()
return nextch(), s
def nextstring(c):
if c == b'"':
return nextdelimited(nextch(), b'"', b'\\')
else:
return nextrun(c, wordchars)
c = nextch()
while c != b'\0':
# pytype: disable=wrong-arg-types
while c in pycompat.bytestr(string.whitespace):
# pytype: enable=wrong-arg-types
c = nextch()
if c == b'.':
yield b'n', (r, [p1])
p1 = r
r += 1
c = nextch()
elif c == b'+':
# pytype: disable=wrong-arg-types
c, digs = nextrun(nextch(), pycompat.bytestr(string.digits))
# pytype: enable=wrong-arg-types
n = int(digs)
for i in range(0, n):
yield b'n', (r, [p1])
p1 = r
r += 1
elif c in b'*/':
if c == b'*':
c = nextch()
c, pref = nextstring(c)
prefs = [pref]
while c == b'/':
c, pref = nextstring(nextch())
prefs.append(pref)
ps = [resolve(ref) for ref in prefs]
yield b'n', (r, ps)
p1 = r
r += 1
elif c == b'<':
c, ref = nextstring(nextch())
p1 = resolve(ref)
elif c == b':':
c, name = nextstring(nextch())
labels[name] = p1
yield b'l', (p1, name)
elif c == b'@':
c, text = nextstring(nextch())
yield b'a', text
elif c == b'!':
c = nextch()
if c == b'!':
cmd = b''
c = nextch()
while c not in b'\n\r\0':
cmd += c
c = nextch()
yield b'C', cmd
else:
c, cmd = nextstring(c)
yield b'c', cmd
elif c == b'#':
while c not in b'\n\r\0':
c = nextch()
elif c == b'$':
p1 = -1
c = nextch()
elif c == b'\0':
return # in case it was preceded by whitespace
else:
s = b''
i = 0
while c != b'\0' and i < 10:
s += c
i += 1
c = nextch()
raise error.Abort(
_(b'invalid character in dag description: %s...') % s
)
def dagtextlines(
events,
addspaces=True,
wraplabels=False,
wrapannotations=False,
wrapcommands=False,
wrapnonlinear=False,
usedots=False,
maxlinewidth=70,
):
'''generates single lines for dagtext()'''
def wrapstring(text):
if re.match(b"^[0-9a-z]*$", text):
return text
return b'"' + text.replace(b'\\', b'\\\\').replace(b'"', b'\"') + b'"'
def gen():
labels = {}
run = 0
wantr = 0
needroot = False
for kind, data in events:
if kind == b'n':
r, ps = data
# sanity check
if r != wantr:
raise error.Abort(_(b"expected id %i, got %i") % (wantr, r))
if not ps:
ps = [-1]
else:
for p in ps:
if p >= r:
raise error.Abort(
_(
b"parent id %i is larger than "
b"current id %i"
)
% (p, r)
)
wantr += 1
# new root?
p1 = r - 1
if len(ps) == 1 and ps[0] == -1:
if needroot:
if run:
yield b'+%d' % run
run = 0
if wrapnonlinear:
yield b'\n'
yield b'$'
p1 = -1
else:
needroot = True
if len(ps) == 1 and ps[0] == p1:
if usedots:
yield b"."
else:
run += 1
else:
if run:
yield b'+%d' % run
run = 0
if wrapnonlinear:
yield b'\n'
prefs = []
for p in ps:
if p == p1:
prefs.append(b'')
elif p in labels:
prefs.append(labels[p])
else:
prefs.append(b'%d' % (r - p))
yield b'*' + b'/'.join(prefs)
else:
if run:
yield b'+%d' % run
run = 0
if kind == b'l':
rid, name = data
labels[rid] = name
yield b':' + name
if wraplabels:
yield b'\n'
elif kind == b'c':
yield b'!' + wrapstring(data)
if wrapcommands:
yield b'\n'
elif kind == b'C':
yield b'!!' + data
yield b'\n'
elif kind == b'a':
if wrapannotations:
yield b'\n'
yield b'@' + wrapstring(data)
elif kind == b'#':
yield b'#' + data
yield b'\n'
else:
raise error.Abort(
_(b"invalid event type in dag: ('%s', '%s')")
% (
stringutil.escapestr(kind),
stringutil.escapestr(data),
)
)
if run:
yield b'+%d' % run
line = b''
for part in gen():
if part == b'\n':
if line:
yield line
line = b''
else:
if len(line) + len(part) >= maxlinewidth:
yield line
line = b''
elif addspaces and line and part != b'.':
line += b' '
line += part
if line:
yield line
def dagtext(
dag,
addspaces=True,
wraplabels=False,
wrapannotations=False,
wrapcommands=False,
wrapnonlinear=False,
usedots=False,
maxlinewidth=70,
):
"""generates lines of a textual representation for a dag event stream
events should generate what parsedag() does, so:
('n', (id, [parentids])) for node creation
('l', (id, labelname)) for labels on nodes
('a', text) for annotations
('c', text) for commands
('C', text) for line commands ('!!')
('#', text) for comment lines
Parent nodes must come before child nodes.
Examples
--------
Linear run:
>>> dagtext([(b'n', (0, [-1])), (b'n', (1, [0]))])
'+2'
Two roots:
>>> dagtext([(b'n', (0, [-1])), (b'n', (1, [-1]))])
'+1 $ +1'
Fork and join:
>>> dagtext([(b'n', (0, [-1])), (b'n', (1, [0])), (b'n', (2, [0])),
... (b'n', (3, [2, 1]))])
'+2 *2 */2'
Fork and join with labels:
>>> dagtext([(b'n', (0, [-1])), (b'l', (0, b'f')), (b'n', (1, [0])),
... (b'l', (1, b'p2')), (b'n', (2, [0])), (b'n', (3, [2, 1]))])
'+1 :f +1 :p2 *f */p2'
Annotations:
>>> dagtext([(b'n', (0, [-1])), (b'a', b'ann'), (b'n', (1, [0]))])
'+1 @ann +1'
>>> dagtext([(b'n', (0, [-1])),
... (b'a', b'my annotation'),
... (b'n', (1, [0]))])
'+1 @"my annotation" +1'
Commands:
>>> dagtext([(b'n', (0, [-1])), (b'c', b'cmd'), (b'n', (1, [0]))])
'+1 !cmd +1'
>>> dagtext([(b'n', (0, [-1])),
... (b'c', b'my command'),
... (b'n', (1, [0]))])
'+1 !"my command" +1'
>>> dagtext([(b'n', (0, [-1])),
... (b'C', b'my command line'),
... (b'n', (1, [0]))])
'+1 !!my command line\\n+1'
Comments:
>>> dagtext([(b'n', (0, [-1])), (b'#', b' comment'), (b'n', (1, [0]))])
'+1 # comment\\n+1'
>>> dagtext([])
''
Combining parsedag and dagtext:
>>> dagtext(parsedag(b'+1 :f +1 :p2 *f */p2'))
'+1 :f +1 :p2 *f */p2'
"""
return b"\n".join(
dagtextlines(
dag,
addspaces,
wraplabels,
wrapannotations,
wrapcommands,
wrapnonlinear,
usedots,
maxlinewidth,
)
)