hgweb: document the revnavgen function

mercurial/hgweb/webutil.py

@@ -1,350 +1,363 b''
 # hgweb/webutil.py - utility library for the web interface.
 #
 # Copyright 21 May 2005 - (c) 2005 Jake Edge <[e-mail]>
 # Copyright 2005-2007 Matt Mackall <[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 os, copy
 from mercurial import match, patch, scmutil, error, ui, util
 from mercurial.i18n import _
 from mercurial.node import hex, nullid
 from common import ErrorResponse
 from common import HTTP_NOT_FOUND
 import difflib
 
 def up(p):
     if p[0] != "/":
         p = "/" + p
     if p[-1] == "/":
         p = p[:-1]
     up = os.path.dirname(p)
     if up == "/":
         return "/"
     return up + "/"
 
 def revnavgen(pos, pagelen, limit, nodefunc):
+    """computes label and revision id for navigation link
+
+    :pos: is the revision relative to which we generate navigation.
+    :pagelen: the size of each navigation page
+    :limit: how far shall we link
+    :nodefun: factory for a changectx from a revision
+
+    The return is:
+        - a single element tuple
+        - containing a dictionary with a `before` and `after` key
+        - values are generator functions taking an arbitrary number of kwargs
+        - yield items are dictionaries with `label` and `node` keys
+    """
     def seq(factor, limit=None):
         if limit:
             yield limit
             if limit >= 20 and limit <= 40:
                 yield 50
         else:
             yield 1 * factor
             yield 3 * factor
         for f in seq(factor * 10):
             yield f
 
     navbefore = []
     navafter = []
 
     last = 0
     for f in seq(1, pagelen):
         if f < pagelen or f <= last:
             continue
         if f > limit:
             break
         last = f
         if pos + f < limit:
             navafter.append(("+%d" % f, hex(nodefunc(pos + f).node())))
         if pos - f >= 0:
             navbefore.insert(0, ("-%d" % f, hex(nodefunc(pos - f).node())))
 
     navafter.append(("tip", "tip"))
     try:
         navbefore.insert(0, ("(0)", hex(nodefunc('0').node())))
     except error.RepoError:
         pass
 
     def gen(l):
         def f(**map):
             for label, node in l:
                 yield {"label": label, "node": node}
         return f
 
     return (dict(before=gen(navbefore), after=gen(navafter)),)
 
 def _siblings(siblings=[], hiderev=None):
     siblings = [s for s in siblings if s.node() != nullid]
     if len(siblings) == 1 and siblings[0].rev() == hiderev:
         return
     for s in siblings:
         d = {'node': s.hex(), 'rev': s.rev()}
         d['user'] = s.user()
         d['date'] = s.date()
         d['description'] = s.description()
         d['branch'] = s.branch()
         if util.safehasattr(s, 'path'):
             d['file'] = s.path()
         yield d
 
 def parents(ctx, hide=None):
     return _siblings(ctx.parents(), hide)
 
 def children(ctx, hide=None):
     return _siblings(ctx.children(), hide)
 
 def renamelink(fctx):
     r = fctx.renamed()
     if r:
         return [dict(file=r[0], node=hex(r[1]))]
     return []
 
 def nodetagsdict(repo, node):
     return [{"name": i} for i in repo.nodetags(node)]
 
 def nodebookmarksdict(repo, node):
     return [{"name": i} for i in repo.nodebookmarks(node)]
 
 def nodebranchdict(repo, ctx):
     branches = []
     branch = ctx.branch()
     # If this is an empty repo, ctx.node() == nullid,
     # ctx.branch() == 'default'.
     try:
         branchnode = repo.branchtip(branch)
     except error.RepoLookupError:
         branchnode = None
     if branchnode == ctx.node():
         branches.append({"name": branch})
     return branches
 
 def nodeinbranch(repo, ctx):
     branches = []
     branch = ctx.branch()
     try:
         branchnode = repo.branchtip(branch)
     except error.RepoLookupError:
         branchnode = None
     if branch != 'default' and branchnode != ctx.node():
         branches.append({"name": branch})
     return branches
 
 def nodebranchnodefault(ctx):
     branches = []
     branch = ctx.branch()
     if branch != 'default':
         branches.append({"name": branch})
     return branches
 
 def showtag(repo, tmpl, t1, node=nullid, **args):
     for t in repo.nodetags(node):
         yield tmpl(t1, tag=t, **args)
 
 def showbookmark(repo, tmpl, t1, node=nullid, **args):
     for t in repo.nodebookmarks(node):
         yield tmpl(t1, bookmark=t, **args)
 
 def cleanpath(repo, path):
     path = path.lstrip('/')
     return scmutil.canonpath(repo.root, '', path)
 
 def changeidctx (repo, changeid):
     try:
         ctx = repo[changeid]
     except error.RepoError:
         man = repo.manifest
         ctx = repo[man.linkrev(man.rev(man.lookup(changeid)))]
 
     return ctx
 
 def changectx (repo, req):
     changeid = "tip"
     if 'node' in req.form:
         changeid = req.form['node'][0]
         ipos=changeid.find(':')
         if ipos != -1:
             changeid = changeid[(ipos + 1):]
     elif 'manifest' in req.form:
         changeid = req.form['manifest'][0]
 
     return changeidctx(repo, changeid)
 
 def basechangectx(repo, req):
     if 'node' in req.form:
         changeid = req.form['node'][0]
         ipos=changeid.find(':')
         if ipos != -1:
             changeid = changeid[:ipos]
             return changeidctx(repo, changeid)
 
     return None
 
 def filectx(repo, req):
     if 'file' not in req.form:
         raise ErrorResponse(HTTP_NOT_FOUND, 'file not given')
     path = cleanpath(repo, req.form['file'][0])
     if 'node' in req.form:
         changeid = req.form['node'][0]
     elif 'filenode' in req.form:
         changeid = req.form['filenode'][0]
     else:
         raise ErrorResponse(HTTP_NOT_FOUND, 'node or filenode not given')
     try:
         fctx = repo[changeid][path]
     except error.RepoError:
         fctx = repo.filectx(path, fileid=changeid)
 
     return fctx
 
 def listfilediffs(tmpl, files, node, max):
     for f in files[:max]:
         yield tmpl('filedifflink', node=hex(node), file=f)
     if len(files) > max:
         yield tmpl('fileellipses')
 
 def diffs(repo, tmpl, ctx, basectx, files, parity, style):
 
     def countgen():
         start = 1
         while True:
             yield start
             start += 1
 
     blockcount = countgen()
     def prettyprintlines(diff, blockno):
         for lineno, l in enumerate(diff.splitlines(True)):
             lineno = "%d.%d" % (blockno, lineno + 1)
             if l.startswith('+'):
                 ltype = "difflineplus"
             elif l.startswith('-'):
                 ltype = "difflineminus"
             elif l.startswith('@'):
                 ltype = "difflineat"
             else:
                 ltype = "diffline"
             yield tmpl(ltype,
                        line=l,
                        lineid="l%s" % lineno,
                        linenumber="% 8s" % lineno)
 
     if files:
         m = match.exact(repo.root, repo.getcwd(), files)
     else:
         m = match.always(repo.root, repo.getcwd())
 
     diffopts = patch.diffopts(repo.ui, untrusted=True)
     if basectx is None:
         parents = ctx.parents()
         node1 = parents and parents[0].node() or nullid
     else:
         node1 = basectx.node()
     node2 = ctx.node()
 
     block = []
     for chunk in patch.diff(repo, node1, node2, m, opts=diffopts):
         if chunk.startswith('diff') and block:
             blockno = blockcount.next()
             yield tmpl('diffblock', parity=parity.next(), blockno=blockno,
                        lines=prettyprintlines(''.join(block), blockno))
             block = []
         if chunk.startswith('diff') and style != 'raw':
             chunk = ''.join(chunk.splitlines(True)[1:])
         block.append(chunk)
     blockno = blockcount.next()
     yield tmpl('diffblock', parity=parity.next(), blockno=blockno,
                lines=prettyprintlines(''.join(block), blockno))
 
 def compare(tmpl, context, leftlines, rightlines):
     '''Generator function that provides side-by-side comparison data.'''
 
     def compline(type, leftlineno, leftline, rightlineno, rightline):
         lineid = leftlineno and ("l%s" % leftlineno) or ''
         lineid += rightlineno and ("r%s" % rightlineno) or ''
         return tmpl('comparisonline',
                     type=type,
                     lineid=lineid,
                     leftlinenumber="% 6s" % (leftlineno or ''),
                     leftline=leftline or '',
                     rightlinenumber="% 6s" % (rightlineno or ''),
                     rightline=rightline or '')
 
     def getblock(opcodes):
         for type, llo, lhi, rlo, rhi in opcodes:
             len1 = lhi - llo
             len2 = rhi - rlo
             count = min(len1, len2)
             for i in xrange(count):
                 yield compline(type=type,
                                leftlineno=llo + i + 1,
                                leftline=leftlines[llo + i],
                                rightlineno=rlo + i + 1,
                                rightline=rightlines[rlo + i])
             if len1 > len2:
                 for i in xrange(llo + count, lhi):
                     yield compline(type=type,
                                    leftlineno=i + 1,
                                    leftline=leftlines[i],
                                    rightlineno=None,
                                    rightline=None)
             elif len2 > len1:
                 for i in xrange(rlo + count, rhi):
                     yield compline(type=type,
                                    leftlineno=None,
                                    leftline=None,
                                    rightlineno=i + 1,
                                    rightline=rightlines[i])
 
     s = difflib.SequenceMatcher(None, leftlines, rightlines)
     if context < 0:
         yield tmpl('comparisonblock', lines=getblock(s.get_opcodes()))
     else:
         for oc in s.get_grouped_opcodes(n=context):
             yield tmpl('comparisonblock', lines=getblock(oc))
 
 def diffstatgen(ctx, basectx):
     '''Generator function that provides the diffstat data.'''
 
     stats = patch.diffstatdata(util.iterlines(ctx.diff(basectx)))
     maxname, maxtotal, addtotal, removetotal, binary = patch.diffstatsum(stats)
     while True:
         yield stats, maxname, maxtotal, addtotal, removetotal, binary
 
 def diffsummary(statgen):
     '''Return a short summary of the diff.'''
 
     stats, maxname, maxtotal, addtotal, removetotal, binary = statgen.next()
     return _(' %d files changed, %d insertions(+), %d deletions(-)\n') % (
              len(stats), addtotal, removetotal)
 
 def diffstat(tmpl, ctx, statgen, parity):
     '''Return a diffstat template for each file in the diff.'''
 
     stats, maxname, maxtotal, addtotal, removetotal, binary = statgen.next()
     files = ctx.files()
 
     def pct(i):
         if maxtotal == 0:
             return 0
         return (float(i) / maxtotal) * 100
 
     fileno = 0
     for filename, adds, removes, isbinary in stats:
         template = filename in files and 'diffstatlink' or 'diffstatnolink'
         total = adds + removes
         fileno += 1
         yield tmpl(template, node=ctx.hex(), file=filename, fileno=fileno,
                    total=total, addpct=pct(adds), removepct=pct(removes),
                    parity=parity.next())
 
 class sessionvars(object):
     def __init__(self, vars, start='?'):
         self.start = start
         self.vars = vars
     def __getitem__(self, key):
         return self.vars[key]
     def __setitem__(self, key, value):
         self.vars[key] = value
     def __copy__(self):
         return sessionvars(copy.copy(self.vars), self.start)
     def __iter__(self):
         separator = self.start
         for key, value in self.vars.iteritems():
             yield {'name': key, 'value': str(value), 'separator': separator}
             separator = '&'
 
 class wsgiui(ui.ui):
     # default termwidth breaks under mod_wsgi
     def termwidth(self):
         return 80