walkchangerevs: move 'add' to callback

Now walkchangerevs is a simple iterator over contexts

hgext/churn.py

@@ -54,13 +54,10 b' def countrate(ui, repo, amap, *pats, **o'
         df = util.matchdate(opts['date'])
 
     m = cmdutil.match(repo, pats, opts)
-    for st, ctx, fns in cmdutil.walkchangerevs(ui, repo, m, opts):
-        if not st == 'add':
-            continue
-
+    def prep(ctx, fns):
         rev = ctx.rev()
         if df and not df(ctx.date()[0]): # doesn't match date format
-            continue
+            return
 
         key = getkey(ctx)
         key = amap.get(key, key) # alias remap
@@ -70,7 +67,7 b' def countrate(ui, repo, amap, *pats, **o'
             parents = ctx.parents()
             if len(parents) > 1:
                 ui.note(_('Revision %d is a merge, ignoring...\n') % (rev,))
-                continue
+                return
 
             ctx1 = parents[0]
             lines = changedlines(ui, repo, ctx1, ctx, fns)
@@ -84,6 +81,9 b' def countrate(ui, repo, amap, *pats, **o'
                 ui.write("\r" + _("generating stats: %d%%") % pct)
                 sys.stdout.flush()
 
+    for ctx in cmdutil.walkchangerevs(ui, repo, m, opts, prep):
+        continue
+
     if opts.get('progress'):
         ui.write("\r")
         sys.stdout.flush()

mercurial/cmdutil.py

@@ -1023,15 +1023,16 b' def show_changeset(ui, repo, opts, buffe'
 def finddate(ui, repo, date):
     """Find the tipmost changeset that matches the given date spec"""
     df = util.matchdate(date)
-    get = util.cachefunc(lambda r: repo[r])
     m = matchall(repo)
     results = {}
-    for st, rev, fns in walkchangerevs(ui, repo, m, get, {'rev':None}):
-        if st == 'add':
-            d = get(rev).date()
+
+    def prep(ctx, fns):
+        d = ctx.date()
             if df(d[0]):
                 results[rev] = d
-        elif st == 'iter':
+
+    for ctx in walkchangerevs(ui, repo, m, {'rev':None}, prep):
+        rev = ctx.rev()
             if rev in results:
                 ui.status(_("Found revision %s from %s\n") %
                           (rev, util.datestr(results[rev])))
@@ -1039,7 +1040,7 b' def finddate(ui, repo, date):'
 
     raise util.Abort(_("revision matching date not found"))
 
-def walkchangerevs(ui, repo, match, opts):
+def walkchangerevs(ui, repo, match, opts, prepare):
     '''Iterate over files and the revs in which they changed.
 
     Callers most commonly need to iterate backwards over the history
@@ -1050,15 +1051,9 b' def walkchangerevs(ui, repo, match, opts'
     window, we first walk forwards to gather data, then in the desired
     order (usually backwards) to display it.
 
-    This function returns an iterator. The iterator yields 3-tuples.
-    They will be of one of the following forms:
-
-    "add", rev, fns: out-of-order traversal of the given filenames
-    fns, which changed during revision rev - use to gather data for
-    possible display
-
-    "iter", rev, None: in-order traversal of the revs earlier iterated
-    over with "add" - use to display data'''
+    This function returns an iterator yielding contexts. Before
+    yielding each context, the iterator will first call the prepare
+    function on each context in the window in forward order.'''
 
     def increasing_windows(start, end, windowsize=8, sizelimit=512):
         if start < end:
@@ -1225,9 +1220,9 b' def walkchangerevs(ui, repo, match, opts'
                             if match(f):
                                 yield f
                     fns = fns_generator()
-                yield 'add', ctx, fns
+                prepare(ctx, fns)
             for rev in nrevs:
-                yield 'iter', change(rev), None
+                yield change(rev)
     return iterate()
 
 def commit(ui, repo, commitfunc, pats, opts):

mercurial/commands.py

@@ -1302,8 +1302,8 b' def grep(ui, repo, pattern, *pats, **opt'
     matchfn = cmdutil.match(repo, pats, opts)
     found = False
     follow = opts.get('follow')
-    for st, ctx, fns in cmdutil.walkchangerevs(ui, repo, matchfn, opts):
-        if st == 'add':
+
+    def prep(ctx, fns):
             rev = ctx.rev()
             pctx = ctx.parents()[0]
             parent = pctx.rev()
@@ -1337,7 +1337,8 b' def grep(ui, repo, pattern, *pats, **opt'
                         grepbody(pfn, parent, flog.read(fnode))
                     except error.LookupError:
                         pass
-        elif st == 'iter':
+
+    for ctx in cmdutil.walkchangerevs(ui, repo, matchfn, opts, prep):
             rev = ctx.rev()
             parent = ctx.parents()[0].rev()
             for fn in sorted(revfiles.get(rev, [])):
@@ -2037,21 +2038,18 b' def log(ui, repo, *pats, **opts):'
     only_branches = opts.get('only_branch')
 
     displayer = cmdutil.show_changeset(ui, repo, opts, True, matchfn)
-    for st, ctx, fns in cmdutil.walkchangerevs(ui, repo, matchfn, opts):
+    def prep(ctx, fns):
         rev = ctx.rev()
-        if st == 'add':
             parents = [p for p in repo.changelog.parentrevs(rev)
                        if p != nullrev]
             if opts.get('no_merges') and len(parents) == 2:
-                continue
+            return
             if opts.get('only_merges') and len(parents) != 2:
-                continue
-
+            return
             if only_branches and ctx.branch() not in only_branches:
-                continue
-
+            return
             if df and not df(ctx.date()[0]):
-                continue
+            return
 
             if opts.get('keyword'):
                 miss = 0
@@ -2062,11 +2060,11 b' def log(ui, repo, *pats, **opts):'
                         miss = 1
                         break
                 if miss:
-                    continue
+                return
 
             if opts['user']:
                 if not [k for k in opts['user'] if k in ctx.user()]:
-                    continue
+                return
 
             copies = []
             if opts.get('copies') and rev:
@@ -2077,10 +2075,9 b' def log(ui, repo, *pats, **opts):'
 
             displayer.show(ctx, copies=copies)
 
-        elif st == 'iter':
-            if count == limit: break
-
-            if displayer.flush(rev):
+    for ctx in cmdutil.walkchangerevs(ui, repo, matchfn, opts, prep):
+        if count != limit:
+            if displayer.flush(ctx.rev()):
                 count += 1
 
 def manifest(ui, repo, node=None, rev=None):