view mercurial/dagparser.py @ 18656:8eb3408bf005

import: don't rollback on failed import --exact (issue3616)

The checkexact() helper function was calling repo.rollback() from inside
an open transaction. In addition to being insane, this is unnecessary
because import will release the transaction on an exception.

It turns out that this has been broken since the feature was first
introduced, first released in v1.0:

changeset:   4263:47ba52121433
user:        Brendan Cully <[e-mail]>
date:        Thu Mar 22 10:44:59 2007 -0700
files:       mercurial/commands.py mercurial/patch.py
description:
Add import --exact.
When this option is set, import will apply the patch (which must
be generated by export) to the parents specified in the patch,
and check that the node produced by the patch matches the node
ID in the patch.

# dagparser.py - parser and generator for concise description of DAGs
#
# Copyright 2010 Peter Arrenbrecht <[e-mail]>
#
# 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, string
import util
from i18n import _

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("""
        ...
        ... +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(""))
        []

    A simple linear run:

        >>> list(parsedag("+3"))
        [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))]

    Some non-standard ways to define such runs:

        >>> list(parsedag("+1+2"))
        [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))]

        >>> list(parsedag("+1*1*"))
        [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))]

        >>> list(parsedag("*"))
        [('n', (0, [-1]))]

        >>> list(parsedag("..."))
        [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [1]))]

    A fork and a join, using numeric back references:

        >>> list(parsedag("+2*2*/2"))
        [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [0])), ('n', (3, [2, 1]))]

        >>> list(parsedag("+2<2+1/2"))
        [('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [0])), ('n', (3, [2, 1]))]

    Placing a label:

        >>> list(parsedag("+1 :mylabel +1"))
        [('n', (0, [-1])), ('l', (0, 'mylabel')), ('n', (1, [0]))]

    An empty label (silly, really):

        >>> list(parsedag("+1:+1"))
        [('n', (0, [-1])), ('l', (0, '')), ('n', (1, [0]))]

    Fork and join, but with labels instead of numeric back references:

        >>> list(parsedag("+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("+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("+1 $ +1"))
        [('n', (0, [-1])), ('n', (1, [-1]))]

    Annotations, which are meant to introduce sticky state for subsequent nodes:

        >>> list(parsedag("+1 @ann +1"))
        [('n', (0, [-1])), ('a', 'ann'), ('n', (1, [0]))]

        >>> list(parsedag('+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("+1 !cmd +1"))
        [('n', (0, [-1])), ('c', 'cmd'), ('n', (1, [0]))]

        >>> list(parsedag('+1 !"my command" +1'))
        [('n', (0, [-1])), ('c', 'my command'), ('n', (1, [0]))]

        >>> list(parsedag('+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('+1 # comment\\n+1'))
        [('n', (0, [-1])), ('n', (1, [0]))]

    Error:

        >>> try: list(parsedag('+1 bad'))
        ... except Exception, e: print e
        invalid character in dag description: bad...

    '''
    if not desc:
        return

    wordchars = string.ascii_letters + string.digits

    labels = {}
    p1 = -1
    r = 0

    def resolve(ref):
        if not ref:
            return p1
        elif ref[0] in string.digits:
            return r - int(ref)
        else:
            return labels[ref]

    chiter = (c for c in desc)

    def nextch():
        try:
            return chiter.next()
        except StopIteration:
            return '\0'

    def nextrun(c, allow):
        s = ''
        while c in allow:
            s += c
            c = nextch()
        return c, s

    def nextdelimited(c, limit, escape):
        s = ''
        while c != limit:
            if c == escape:
                c = nextch()
            s += c
            c = nextch()
        return nextch(), s

    def nextstring(c):
        if c == '"':
            return nextdelimited(nextch(), '"', '\\')
        else:
            return nextrun(c, wordchars)

    c = nextch()
    while c != '\0':
        while c in string.whitespace:
            c = nextch()
        if c == '.':
            yield 'n', (r, [p1])
            p1 = r
            r += 1
            c = nextch()
        elif c == '+':
            c, digs = nextrun(nextch(), string.digits)
            n = int(digs)
            for i in xrange(0, n):
                yield 'n', (r, [p1])
                p1 = r
                r += 1
        elif c in '*/':
            if c == '*':
                c = nextch()
            c, pref = nextstring(c)
            prefs = [pref]
            while c == '/':
                c, pref = nextstring(nextch())
                prefs.append(pref)
            ps = [resolve(ref) for ref in prefs]
            yield 'n', (r, ps)
            p1 = r
            r += 1
        elif c == '<':
            c, ref = nextstring(nextch())
            p1 = resolve(ref)
        elif c == ':':
            c, name = nextstring(nextch())
            labels[name] = p1
            yield 'l', (p1, name)
        elif c == '@':
            c, text = nextstring(nextch())
            yield 'a', text
        elif c == '!':
            c = nextch()
            if c == '!':
                cmd = ''
                c = nextch()
                while c not in '\n\r\0':
                    cmd += c
                    c = nextch()
                yield 'C', cmd
            else:
                c, cmd = nextstring(c)
                yield 'c', cmd
        elif c == '#':
            while c not in '\n\r\0':
                c = nextch()
        elif c == '$':
            p1 = -1
            c = nextch()
        elif c == '\0':
            return # in case it was preceded by whitespace
        else:
            s = ''
            i = 0
            while c != '\0' and i < 10:
                s += c
                i += 1
                c = nextch()
            raise util.Abort(_('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("^[0-9a-z]*$", text):
            return text
        return '"' + text.replace('\\', '\\\\').replace('"', '\"') + '"'

    def gen():
        labels = {}
        run = 0
        wantr = 0
        needroot = False
        for kind, data in events:
            if kind == 'n':
                r, ps = data

                # sanity check
                if r != wantr:
                    raise util.Abort(_("expected id %i, got %i") % (wantr, r))
                if not ps:
                    ps = [-1]
                else:
                    for p in ps:
                        if p >= r:
                            raise util.Abort(_("parent id %i is larger than "
                                               "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 '+' + str(run)
                            run = 0
                        if wrapnonlinear:
                            yield '\n'
                        yield '$'
                        p1 = -1
                    else:
                        needroot = True
                if len(ps) == 1 and ps[0] == p1:
                    if usedots:
                        yield "."
                    else:
                        run += 1
                else:
                    if run:
                        yield '+' + str(run)
                        run = 0
                    if wrapnonlinear:
                        yield '\n'
                    prefs = []
                    for p in ps:
                        if p == p1:
                            prefs.append('')
                        elif p in labels:
                            prefs.append(labels[p])
                        else:
                            prefs.append(str(r - p))
                    yield '*' + '/'.join(prefs)
            else:
                if run:
                    yield '+' + str(run)
                    run = 0
                if kind == 'l':
                    rid, name = data
                    labels[rid] = name
                    yield ':' + name
                    if wraplabels:
                        yield '\n'
                elif kind == 'c':
                    yield '!' + wrapstring(data)
                    if wrapcommands:
                        yield '\n'
                elif kind == 'C':
                    yield '!!' + data
                    yield '\n'
                elif kind == 'a':
                    if wrapannotations:
                        yield '\n'
                    yield '@' + wrapstring(data)
                elif kind == '#':
                    yield '#' + data
                    yield '\n'
                else:
                    raise util.Abort(_("invalid event type in dag: %s")
                                     % str((type, data)))
        if run:
            yield '+' + str(run)

    line = ''
    for part in gen():
        if part == '\n':
            if line:
                yield line
                line = ''
        else:
            if len(line) + len(part) >= maxlinewidth:
                yield line
                line = ''
            elif addspaces and line and part != '.':
                line += ' '
            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([('n', (0, [-1])), ('n', (1, [0]))])
        '+2'

    Two roots:

        >>> dagtext([('n', (0, [-1])), ('n', (1, [-1]))])
        '+1 $ +1'

    Fork and join:

        >>> dagtext([('n', (0, [-1])), ('n', (1, [0])), ('n', (2, [0])),
        ...          ('n', (3, [2, 1]))])
        '+2 *2 */2'

    Fork and join with labels:

        >>> dagtext([('n', (0, [-1])), ('l', (0, 'f')), ('n', (1, [0])),
        ...          ('l', (1, 'p2')), ('n', (2, [0])), ('n', (3, [2, 1]))])
        '+1 :f +1 :p2 *f */p2'

    Annotations:

        >>> dagtext([('n', (0, [-1])), ('a', 'ann'), ('n', (1, [0]))])
        '+1 @ann +1'

        >>> dagtext([('n', (0, [-1])),
        ...          ('a', 'my annotation'),
        ...          ('n', (1, [0]))])
        '+1 @"my annotation" +1'

    Commands:

        >>> dagtext([('n', (0, [-1])), ('c', 'cmd'), ('n', (1, [0]))])
        '+1 !cmd +1'

        >>> dagtext([('n', (0, [-1])), ('c', 'my command'), ('n', (1, [0]))])
        '+1 !"my command" +1'

        >>> dagtext([('n', (0, [-1])),
        ...          ('C', 'my command line'),
        ...          ('n', (1, [0]))])
        '+1 !!my command line\\n+1'

    Comments:

        >>> dagtext([('n', (0, [-1])), ('#', ' comment'), ('n', (1, [0]))])
        '+1 # comment\\n+1'

        >>> dagtext([])
        ''

    Combining parsedag and dagtext:

        >>> dagtext(parsedag('+1 :f +1 :p2 *f */p2'))
        '+1 :f +1 :p2 *f */p2'

    '''
    return "\n".join(dagtextlines(dag,
                                  addspaces,
                                  wraplabels,
                                  wrapannotations,
                                  wrapcommands,
                                  wrapnonlinear,
                                  usedots,
                                  maxlinewidth))