Mercurial > hg
view mercurial/graphmod.py @ 31765:264baeef3588
show: new extension for displaying various repository data
Currently, Mercurial has a number of commands to show information. And,
there are features coming down the pipe that will introduce more
commands for showing information.
Currently, when introducing a new class of data or a view that we
wish to expose to the user, the strategy is to introduce a new command
or overload an existing command, sometimes both. For example, there is
a desire to formalize the wip/smartlog/underway/mine functionality that
many have devised. There is also a desire to introduce a "topics"
concept. Others would like views of "the current stack." In the
current model, we'd need a new command for wip/smartlog/etc (that
behaves a lot like a pre-defined alias of `hg log`). For topics,
we'd likely overload `hg topic[s]` to both display and manipulate
topics.
Adding new commands for every pre-defined query doesn't scale well
and pollutes `hg help`. Overloading commands to perform read-only and
write operations is arguably an UX anti-pattern: while having all
functionality for a given concept in one command is nice, having a
single command doing multiple discrete operations is not. Furthermore,
a user may be surprised that a command they thought was read-only
actually changes something.
We discussed this at the Mercurial 4.0 Sprint in Paris and decided that
having a single command where we could hang pre-defined views of
various data would be a good idea. Having such a command would:
* Help prevent an explosion of new query-related commands
* Create a clear separation between read and write operations
(mitigates footguns)
* Avoids overloading the meaning of commands that manipulate data
(bookmark, tag, branch, etc) (while we can't take away the
existing behavior for BC reasons, we now won't introduce this
behavior on new commands)
* Allows users to discover informational views more easily by
aggregating them in a single location
* Lowers the barrier to creating the new views (since the barrier
to creating a top-level command is relatively high)
So, this commit introduces the `hg show` command via the "show"
extension. This command accepts a positional argument of the
"view" to show. New views can be registered with a decorator. To
prove it works, we implement the "bookmarks" view, which shows a
table of bookmarks and their associated nodes.
We introduce a new style to hold everything used by `hg show`.
For our initial bookmarks view, the output varies from `hg bookmarks`:
* Padding is performed in the template itself as opposed to Python
* Revision integers are not shown
* shortest() is used to display a 5 character node by default (as
opposed to static 12 characters)
I chose to implement the "bookmarks" view first because it is simple
and shouldn't invite too much bikeshedding that detracts from the
evaluation of `hg show` itself. But there is an important point
to consider: we now have 2 ways to show a list of bookmarks. I'm not
a fan of introducing multiple ways to do very similar things. So it
might be worth discussing how we wish to tackle this issue for
bookmarks, tags, branches, MQ series, etc.
I also made the choice of explicitly declaring the default show
template not part of the standard BC guarantees. History has shown
that we make mistakes and poor choices with output formatting but
can't fix these mistakes later because random tools are parsing
output and we don't want to break these tools. Optimizing for human
consumption is one of my goals for `hg show`. So, by not covering
the formatting as part of BC, the barrier to future change is much
lower and humans benefit.
There are some improvements that can be made to formatting. For
example, we don't yet use label() in the templates. We obviously
want this for color. But I'm not sure if we should reuse the existing
log.* labels or invent new ones. I figure we can punt that to a
follow-up.
At the aforementioned Sprint, we discussed and discarded various
alternatives to `hg show`.
We considered making `hg log <view>` perform this behavior. The main
reason we can't do this is because a positional argument to `hg log`
can be a file path and if there is a conflict between a path name and
a view name, behavior is ambiguous. We could have introduced
`hg log --view` or similar, but we felt that required too much typing
(we don't want to require a command flag to show a view) and wasn't
very discoverable. Furthermore, `hg log` is optimized for showing
changelog data and there are things that `hg display` could display
that aren't changelog centric.
There were concerns about using "show" as the command name.
Some users already have a "show" alias that is similar to `hg export`.
There were also concerns that Git users adapted to `git show` would
be confused by `hg show`'s different behavior. The main difference
here is `git show` prints an `hg export` like view of the current
commit by default and `hg show` requires an argument. `git show`
can also display any Git object. `git show` does not support
displaying more complex views: just single objects. If we
implemented `hg show <hash>` or `hg show <identifier>`, `hg show`
would be a superset of `git show`. Although, I'm hesitant to do that
at this time because I view `hg show` as a higher-level querying
command and there are namespace collisions between valid identifiers
and registered views.
There is also a prefix collision with `hg showconfig`, which is an
alias of `hg config`.
We also considered `hg view`, but that is already used by the "hgk"
extension.
`hg display` was also proposed at one point. It has a prefix collision
with `hg diff`. General consensus was "show" or "view" are the best
verbs. And since "view" was taken, "show" was chosen.
There are a number of inline TODOs in this patch. Some of these
represent decisions yet to be made. Others represent features
requiring non-trivial complexity. Rather than bloat the patch or
invite additional bikeshedding, I figured I'd document future
enhancements via TODO so we can get a minimal implmentation landed.
Something is better than nothing.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 24 Mar 2017 19:19:00 -0700 |
parents | d0b9e9803caf |
children | 906da89821ce |
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# Revision graph generator for Mercurial # # Copyright 2008 Dirkjan Ochtman <dirkjan@ochtman.nl> # Copyright 2007 Joel Rosdahl <joel@rosdahl.net> # # 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 ( revset, 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. """ if not revs: return 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(revset.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, lines, 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) 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 yield (type, char, lines, (nodeidx, edges, ncols, nmorecols)) char = '\\' lines = [] 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 # remove current node from edge characters, no longer needed state['edges'].pop(rev, None) yield (type, char, lines, (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 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] shift_interline.extend(' ' * (2 + coldiff)) count = ncols - idx - 1 if coldiff == -1: shift_interline.extend('/ ' * count) elif coldiff == 0: shift_interline.extend(echars[(idx + 1) * 2:ncols * 2]) else: shift_interline.extend(r'\ ' * count) # 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') # ... and start over state['lastcoldiff'] = coldiff state['lastindex'] = idx