procutil: make stream detection in make_line_buffered more correct and strict
In make_line_buffered(), we don’t want to wrap the stream if we know that lines
get flushed to the underlying raw stream already.
Previously, the heuristic was too optimistic. It assumed that any stream which
is not an instance of io.BufferedIOBase doesn’t need wrapping. However, there
are buffered streams that aren’t instances of io.BufferedIOBase, like
Mercurial’s own winstdout.
The new logic is different in two ways:
First, only for the check, if unwraps any combination of WriteAllWrapper and
winstdout.
Second, it skips wrapping the stream only if it is an instance of io.RawIOBase
(or already wrapped). If it is an instance of io.BufferedIOBase, it gets
wrapped. In any other case, the function raises an exception. This ensures
that, if an unknown stream is passed or we add another wrapper in the future,
we don’t wrap the stream if it’s already line buffered or not wrap the stream
if it’s not line buffered. In fact, this was already helpful during development
of this change. Without it, I possibly would have forgot that WriteAllWrapper
needs to be ignored for the check, leading to unnecessary wrapping if stdout is
unbuffered.
The alternative would have been to always wrap unknown streams. However, I
don’t think that anyone would benefit from being less strict. We can expect
streams from the standard library to be subclassing either io.RawIOBase or
io.BufferedIOBase, so running Mercurial in the standard way should not regress
by this change. Py2exe might replace sys.stdout and sys.stderr, but that
currently breaks Mercurial anyway and also these streams don’t claim to be
interactive, so this function is not called for them.
# 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,
)
)