graph: add outputgraph() function, called by ascii() to print

the graph to the ui.

This allows a cleaner entrypoint for extensions to tweak the
graph output without needing to rewrite all of ascii(), or needing
to manually guess where the graph nodes/edges end and the rev
note portion begins.

This patch does not affect graph output or behavior in any way.

Differential Revision: https://phab.mercurial-scm.org/D3655

mercurial/graphmod.py

@@ -1,478 +1,493 b''
 # Revision graph generator for Mercurial
 #
 # Copyright 2008 Dirkjan Ochtman <[e-mail]>
 # Copyright 2007 Joel Rosdahl <[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.
 
 """supports walking the history as DAGs suitable for graphical output
 
 The most basic format we use is that of::
 
   (id, type, data, [parentids])
 
 The node and parent ids are arbitrary integers which identify a node in the
 context of the graph returned. Type is a constant specifying the node type.
 Data depends on type.
 """
 
 from __future__ import absolute_import
 
 from .node import nullrev
 from . import (
     dagop,
     smartset,
     util,
 )
 
 CHANGESET = 'C'
 PARENT = 'P'
 GRANDPARENT = 'G'
 MISSINGPARENT = 'M'
 # Style of line to draw. None signals a line that ends and is removed at this
 # point. A number prefix means only the last N characters of the current block
 # will use that style, the rest will use the PARENT style. Add a - sign
 # (so making N negative) and all but the first N characters use that style.
 EDGES = {PARENT: '|', GRANDPARENT: ':', MISSINGPARENT: None}
 
 def dagwalker(repo, revs):
     """cset DAG generator yielding (id, CHANGESET, ctx, [parentinfo]) tuples
 
     This generator function walks through revisions (which should be ordered
     from bigger to lower). It returns a tuple for each node.
 
     Each parentinfo entry is a tuple with (edgetype, parentid), where edgetype
     is one of PARENT, GRANDPARENT or MISSINGPARENT. The node and parent ids
     are arbitrary integers which identify a node in the context of the graph
     returned.
 
     """
     gpcache = {}
 
     for rev in revs:
         ctx = repo[rev]
         # partition into parents in the rev set and missing parents, then
         # augment the lists with markers, to inform graph drawing code about
         # what kind of edge to draw between nodes.
         pset = set(p.rev() for p in ctx.parents() if p.rev() in revs)
         mpars = [p.rev() for p in ctx.parents()
                  if p.rev() != nullrev and p.rev() not in pset]
         parents = [(PARENT, p) for p in sorted(pset)]
 
         for mpar in mpars:
             gp = gpcache.get(mpar)
             if gp is None:
                 # precompute slow query as we know reachableroots() goes
                 # through all revs (issue4782)
                 if not isinstance(revs, smartset.baseset):
                     revs = smartset.baseset(revs)
                 gp = gpcache[mpar] = sorted(set(dagop.reachableroots(
                     repo, revs, [mpar])))
             if not gp:
                 parents.append((MISSINGPARENT, mpar))
                 pset.add(mpar)
             else:
                 parents.extend((GRANDPARENT, g) for g in gp if g not in pset)
                 pset.update(gp)
 
         yield (ctx.rev(), CHANGESET, ctx, parents)
 
 def nodes(repo, nodes):
     """cset DAG generator yielding (id, CHANGESET, ctx, [parentids]) tuples
 
     This generator function walks the given nodes. It only returns parents
     that are in nodes, too.
     """
     include = set(nodes)
     for node in nodes:
         ctx = repo[node]
         parents = set((PARENT, p.rev()) for p in ctx.parents()
                       if p.node() in include)
         yield (ctx.rev(), CHANGESET, ctx, sorted(parents))
 
 def colored(dag, repo):
     """annotates a DAG with colored edge information
 
     For each DAG node this function emits tuples::
 
       (id, type, data, (col, color), [(col, nextcol, color)])
 
     with the following new elements:
 
       - Tuple (col, color) with column and color index for the current node
       - A list of tuples indicating the edges between the current node and its
         parents.
     """
     seen = []
     colors = {}
     newcolor = 1
     config = {}
 
     for key, val in repo.ui.configitems('graph'):
         if '.' in key:
             branch, setting = key.rsplit('.', 1)
             # Validation
             if setting == "width" and val.isdigit():
                 config.setdefault(branch, {})[setting] = int(val)
             elif setting == "color" and val.isalnum():
                 config.setdefault(branch, {})[setting] = val
 
     if config:
         getconf = util.lrucachefunc(
             lambda rev: config.get(repo[rev].branch(), {}))
     else:
         getconf = lambda rev: {}
 
     for (cur, type, data, parents) in dag:
 
         # Compute seen and next
         if cur not in seen:
             seen.append(cur) # new head
             colors[cur] = newcolor
             newcolor += 1
 
         col = seen.index(cur)
         color = colors.pop(cur)
         next = seen[:]
 
         # Add parents to next
         addparents = [p for pt, p in parents if p not in next]
         next[col:col + 1] = addparents
 
         # Set colors for the parents
         for i, p in enumerate(addparents):
             if not i:
                 colors[p] = color
             else:
                 colors[p] = newcolor
                 newcolor += 1
 
         # Add edges to the graph
         edges = []
         for ecol, eid in enumerate(seen):
             if eid in next:
                 bconf = getconf(eid)
                 edges.append((
                     ecol, next.index(eid), colors[eid],
                     bconf.get('width', -1),
                     bconf.get('color', '')))
             elif eid == cur:
                 for ptype, p in parents:
                     bconf = getconf(p)
                     edges.append((
                         ecol, next.index(p), color,
                         bconf.get('width', -1),
                         bconf.get('color', '')))
 
         # Yield and move on
         yield (cur, type, data, (col, color), edges)
         seen = next
 
 def asciiedges(type, char, state, rev, parents):
     """adds edge info to changelog DAG walk suitable for ascii()"""
     seen = state['seen']
     if rev not in seen:
         seen.append(rev)
     nodeidx = seen.index(rev)
 
     knownparents = []
     newparents = []
     for ptype, parent in parents:
         if parent == rev:
             # self reference (should only be seen in null rev)
             continue
         if parent in seen:
             knownparents.append(parent)
         else:
             newparents.append(parent)
             state['edges'][parent] = state['styles'].get(ptype, '|')
 
     ncols = len(seen)
     width = 1 + ncols * 2
     nextseen = seen[:]
     nextseen[nodeidx:nodeidx + 1] = newparents
     edges = [(nodeidx, nextseen.index(p)) for p in knownparents]
 
     seen[:] = nextseen
     while len(newparents) > 2:
         # ascii() only knows how to add or remove a single column between two
         # calls. Nodes with more than two parents break this constraint so we
         # introduce intermediate expansion lines to grow the active node list
         # slowly.
         edges.append((nodeidx, nodeidx))
         edges.append((nodeidx, nodeidx + 1))
         nmorecols = 1
         width += 2
         yield (type, char, width, (nodeidx, edges, ncols, nmorecols))
         char = '\\'
         nodeidx += 1
         ncols += 1
         edges = []
         del newparents[0]
 
     if len(newparents) > 0:
         edges.append((nodeidx, nodeidx))
     if len(newparents) > 1:
         edges.append((nodeidx, nodeidx + 1))
     nmorecols = len(nextseen) - ncols
     if nmorecols > 0:
         width += 2
     # remove current node from edge characters, no longer needed
     state['edges'].pop(rev, None)
     yield (type, char, width, (nodeidx, edges, ncols, nmorecols))
 
 def _fixlongrightedges(edges):
     for (i, (start, end)) in enumerate(edges):
         if end > start:
             edges[i] = (start, end + 1)
 
 def _getnodelineedgestail(
         echars, idx, pidx, ncols, coldiff, pdiff, fix_tail):
     if fix_tail and coldiff == pdiff and coldiff != 0:
         # Still going in the same non-vertical direction.
         if coldiff == -1:
             start = max(idx + 1, pidx)
             tail = echars[idx * 2:(start - 1) * 2]
             tail.extend(["/", " "] * (ncols - start))
             return tail
         else:
             return ["\\", " "] * (ncols - idx - 1)
     else:
         remainder = (ncols - idx - 1)
         return echars[-(remainder * 2):] if remainder > 0 else []
 
 def _drawedges(echars, edges, nodeline, interline):
     for (start, end) in edges:
         if start == end + 1:
             interline[2 * end + 1] = "/"
         elif start == end - 1:
             interline[2 * start + 1] = "\\"
         elif start == end:
             interline[2 * start] = echars[2 * start]
         else:
             if 2 * end >= len(nodeline):
                 continue
             nodeline[2 * end] = "+"
             if start > end:
                 (start, end) = (end, start)
             for i in range(2 * start + 1, 2 * end):
                 if nodeline[i] != "+":
                     nodeline[i] = "-"
 
 def _getpaddingline(echars, idx, ncols, edges):
     # all edges up to the current node
     line = echars[:idx * 2]
     # an edge for the current node, if there is one
     if (idx, idx - 1) in edges or (idx, idx) in edges:
         # (idx, idx - 1)      (idx, idx)
         # | | | |           | | | |
         # +---o |           | o---+
         # | | X |           | X | |
         # | |/ /            | |/ /
         # | | |             | | |
         line.extend(echars[idx * 2:(idx + 1) * 2])
     else:
         line.extend([' ', ' '])
     # all edges to the right of the current node
     remainder = ncols - idx - 1
     if remainder > 0:
         line.extend(echars[-(remainder * 2):])
     return line
 
 def _drawendinglines(lines, extra, edgemap, seen):
     """Draw ending lines for missing parent edges
 
     None indicates an edge that ends at between this node and the next
     Replace with a short line ending in ~ and add / lines to any edges to
     the right.
 
     """
     if None not in edgemap.values():
         return
 
     # Check for more edges to the right of our ending edges.
     # We need enough space to draw adjustment lines for these.
     edgechars = extra[::2]
     while edgechars and edgechars[-1] is None:
         edgechars.pop()
     shift_size = max((edgechars.count(None) * 2) - 1, 0)
     while len(lines) < 3 + shift_size:
         lines.append(extra[:])
 
     if shift_size:
         empties = []
         toshift = []
         first_empty = extra.index(None)
         for i, c in enumerate(extra[first_empty::2], first_empty // 2):
             if c is None:
                 empties.append(i * 2)
             else:
                 toshift.append(i * 2)
         targets = list(range(first_empty, first_empty + len(toshift) * 2, 2))
         positions = toshift[:]
         for line in lines[-shift_size:]:
             line[first_empty:] = [' '] * (len(line) - first_empty)
             for i in range(len(positions)):
                 pos = positions[i] - 1
                 positions[i] = max(pos, targets[i])
                 line[pos] = '/' if pos > targets[i] else extra[toshift[i]]
 
     map = {1: '|', 2: '~'}
     for i, line in enumerate(lines):
         if None not in line:
             continue
         line[:] = [c or map.get(i, ' ') for c in line]
 
     # remove edges that ended
     remove = [p for p, c in edgemap.items() if c is None]
     for parent in remove:
         del edgemap[parent]
         seen.remove(parent)
 
 def asciistate():
     """returns the initial value for the "state" argument to ascii()"""
     return {
         'seen': [],
         'edges': {},
         'lastcoldiff': 0,
         'lastindex': 0,
         'styles': EDGES.copy(),
         'graphshorten': False,
     }
 
+def outputgraph(ui, graph):
+    """outputs an ASCII graph of a DAG
+
+    this is a helper function for 'ascii' below.
+
+    takes the following arguments:
+
+    - ui to write to
+    - graph data: list of { graph nodes/edges, text }
+
+    this function can be monkey-patched by extensions to alter graph display
+    without needing to mimic all of the edge-fixup logic in ascii()
+    """
+    for (ln, logstr) in graph:
+        ui.write((ln + logstr).rstrip() + "\n")
+
 def ascii(ui, state, type, char, text, coldata):
     """prints an ASCII graph of the DAG
 
     takes the following arguments (one call per node in the graph):
 
       - ui to write to
       - Somewhere to keep the needed state in (init to asciistate())
       - Column of the current node in the set of ongoing edges.
       - Type indicator of node data, usually 'C' for changesets.
       - Payload: (char, lines):
         - Character to use as node's symbol.
         - List of lines to display as the node's text.
       - Edges; a list of (col, next_col) indicating the edges between
         the current node and its parents.
       - Number of columns (ongoing edges) in the current revision.
       - The difference between the number of columns (ongoing edges)
         in the next revision and the number of columns (ongoing edges)
         in the current revision. That is: -1 means one column removed;
         0 means no columns added or removed; 1 means one column added.
     """
     idx, edges, ncols, coldiff = coldata
     assert -2 < coldiff < 2
 
     edgemap, seen = state['edges'], state['seen']
     # Be tolerant of history issues; make sure we have at least ncols + coldiff
     # elements to work with. See test-glog.t for broken history test cases.
     echars = [c for p in seen for c in (edgemap.get(p, '|'), ' ')]
     echars.extend(('|', ' ') * max(ncols + coldiff - len(seen), 0))
 
     if coldiff == -1:
         # Transform
         #
         #     | | |        | | |
         #     o | |  into  o---+
         #     |X /         |/ /
         #     | |          | |
         _fixlongrightedges(edges)
 
     # add_padding_line says whether to rewrite
     #
     #     | | | |        | | | |
     #     | o---+  into  | o---+
     #     |  / /         |   | |  # <--- padding line
     #     o | |          |  / /
     #                    o | |
     add_padding_line = (len(text) > 2 and coldiff == -1 and
                         [x for (x, y) in edges if x + 1 < y])
 
     # fix_nodeline_tail says whether to rewrite
     #
     #     | | o | |        | | o | |
     #     | | |/ /         | | |/ /
     #     | o | |    into  | o / /   # <--- fixed nodeline tail
     #     | |/ /           | |/ /
     #     o | |            o | |
     fix_nodeline_tail = len(text) <= 2 and not add_padding_line
 
     # nodeline is the line containing the node character (typically o)
     nodeline = echars[:idx * 2]
     nodeline.extend([char, " "])
 
     nodeline.extend(
         _getnodelineedgestail(
             echars, idx, state['lastindex'], ncols, coldiff,
             state['lastcoldiff'], fix_nodeline_tail))
 
     # shift_interline is the line containing the non-vertical
     # edges between this entry and the next
     shift_interline = echars[:idx * 2]
     for i in xrange(2 + coldiff):
         shift_interline.append(' ')
     count = ncols - idx - 1
     if coldiff == -1:
         for i in xrange(count):
             shift_interline.extend(['/', ' '])
     elif coldiff == 0:
         shift_interline.extend(echars[(idx + 1) * 2:ncols * 2])
     else:
         for i in xrange(count):
             shift_interline.extend(['\\', ' '])
 
     # draw edges from the current node to its parents
     _drawedges(echars, edges, nodeline, shift_interline)
 
     # lines is the list of all graph lines to print
     lines = [nodeline]
     if add_padding_line:
         lines.append(_getpaddingline(echars, idx, ncols, edges))
 
     # If 'graphshorten' config, only draw shift_interline
     # when there is any non vertical flow in graph.
     if state['graphshorten']:
         if any(c in '\/' for c in shift_interline if c):
             lines.append(shift_interline)
     # Else, no 'graphshorten' config so draw shift_interline.
     else:
         lines.append(shift_interline)
 
     # make sure that there are as many graph lines as there are
     # log strings
     extra_interline = echars[:(ncols + coldiff) * 2]
     if len(lines) < len(text):
         while len(lines) < len(text):
             lines.append(extra_interline[:])
 
     _drawendinglines(lines, extra_interline, edgemap, seen)
 
     while len(text) < len(lines):
         text.append("")
 
     if any(len(char) > 1 for char in edgemap.values()):
         # limit drawing an edge to the first or last N lines of the current
         # section the rest of the edge is drawn like a parent line.
         parent = state['styles'][PARENT][-1:]
         def _drawgp(char, i):
             # should a grandparent character be drawn for this line?
             if len(char) < 2:
                 return True
             num = int(char[:-1])
             # either skip first num lines or take last num lines, based on sign
             return -num <= i if num < 0 else (len(lines) - i) <= num
         for i, line in enumerate(lines):
             line[:] = [c[-1:] if _drawgp(c, i) else parent for c in line]
         edgemap.update(
             (e, (c if len(c) < 2 else parent)) for e, c in edgemap.items())
 
     # print lines
     indentation_level = max(ncols, ncols + coldiff)
-    for (line, logstr) in zip(lines, text):
-        ln = "%-*s %s" % (2 * indentation_level, "".join(line), logstr)
-        ui.write(ln.rstrip() + '\n')
+    lines = ["%-*s " % (2 * indentation_level, "".join(line)) for line in lines]
+    outputgraph(ui, zip(lines, text))
 
     # ... and start over
     state['lastcoldiff'] = coldiff
     state['lastindex'] = idx