merge-event-log-tags.py revision b75105315187ec2719bdc8adfdea6fc4f6b296ef 
1#!/usr/bin/env python
2#
3# Copyright (C) 2009 The Android Open Source Project
4#
5# Licensed under the Apache License, Version 2.0 (the "License");
6# you may not use this file except in compliance with the License.
7# You may obtain a copy of the License at
8#
9#      http://www.apache.org/licenses/LICENSE-2.0
10#
11# Unless required by applicable law or agreed to in writing, software
12# distributed under the License is distributed on an "AS IS" BASIS,
13# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14# See the License for the specific language governing permissions and
15# limitations under the License.
16
17"""
18Usage: merge-event-log-tags.py [-o output_file] [input_files...]
19
20Merge together zero or more event-logs-tags files to produce a single
21output file, stripped of comments.  Checks that no tag numbers conflict
22and fails if they do.
23
24-h to display this usage message and exit.
25"""
26
27import cStringIO
28import getopt
29import md5
30import struct
31import sys
32
33import event_log_tags
34
35errors = []
36warnings = []
37
38output_file = None
39pre_merged_file = None
40
41# Tags with a tag number of ? are assigned a tag in the range
42# [ASSIGN_START, ASSIGN_LIMIT).
43ASSIGN_START = 900000
44ASSIGN_LIMIT = 1000000
45
46try:
47  opts, args = getopt.getopt(sys.argv[1:], "ho:m:")
48except getopt.GetoptError, err:
49  print str(err)
50  print __doc__
51  sys.exit(2)
52
53for o, a in opts:
54  if o == "-h":
55    print __doc__
56    sys.exit(2)
57  elif o == "-o":
58    output_file = a
59  elif o == "-m":
60    pre_merged_file = a
61  else:
62    print >> sys.stderr, "unhandled option %s" % (o,)
63    sys.exit(1)
64
65# Restrictions on tags:
66#
67#   Tag names must be unique.  (If the tag number and description are
68#   also the same, a warning is issued instead of an error.)
69#
70#   Explicit tag numbers must be unique.  (If the tag name is also the
71#   same, no error is issued because the above rule will issue a
72#   warning or error.)
73
74by_tagname = {}
75by_tagnum = {}
76
77pre_merged_tags = {}
78if pre_merged_file:
79  for t in event_log_tags.TagFile(pre_merged_file).tags:
80    pre_merged_tags[t.tagname] = t
81
82for fn in args:
83  tagfile = event_log_tags.TagFile(fn)
84
85  for t in tagfile.tags:
86    tagnum = t.tagnum
87    tagname = t.tagname
88    description = t.description
89
90    if t.tagname in by_tagname:
91      orig = by_tagname[t.tagname]
92
93      # Allow an explicit tag number to define an implicit tag number
94      if orig.tagnum is None:
95        orig.tagnum = t.tagnum
96      elif t.tagnum is None:
97        t.tagnum = orig.tagnum
98
99      if (t.tagnum == orig.tagnum and
100          t.description == orig.description):
101        # if the name and description are identical, issue a warning
102        # instead of failing (to make it easier to move tags between
103        # projects without breaking the build).
104        tagfile.AddWarning("tag \"%s\" (%s) duplicated in %s:%d" %
105                           (t.tagname, t.tagnum, orig.filename, orig.linenum),
106                           linenum=t.linenum)
107      else:
108        tagfile.AddError(
109            "tag name \"%s\" used by conflicting tag %s from %s:%d" %
110            (t.tagname, orig.tagnum, orig.filename, orig.linenum),
111            linenum=t.linenum)
112      continue
113
114    if t.tagnum is not None and t.tagnum in by_tagnum:
115      orig = by_tagnum[t.tagnum]
116
117      if t.tagname != orig.tagname:
118        tagfile.AddError(
119            "tag number %d used by conflicting tag \"%s\" from %s:%d" %
120            (t.tagnum, orig.tagname, orig.filename, orig.linenum),
121            linenum=t.linenum)
122        continue
123
124    by_tagname[t.tagname] = t
125    if t.tagnum is not None:
126      by_tagnum[t.tagnum] = t
127
128  errors.extend(tagfile.errors)
129  warnings.extend(tagfile.warnings)
130
131if errors:
132  for fn, ln, msg in errors:
133    print >> sys.stderr, "%s:%d: error: %s" % (fn, ln, msg)
134  sys.exit(1)
135
136if warnings:
137  for fn, ln, msg in warnings:
138    print >> sys.stderr, "%s:%d: warning: %s" % (fn, ln, msg)
139
140# Python's hash function (a) isn't great and (b) varies between
141# versions of python.  Using md5 is overkill here but is the same from
142# platform to platform and speed shouldn't matter in practice.
143def hashname(str):
144  d = md5.md5(str).digest()[:4]
145  return struct.unpack("!I", d)[0]
146
147# Assign a tag number to all the entries that say they want one
148# assigned.  We do this based on a hash of the tag name so that the
149# numbers should stay relatively stable as tags are added.
150
151# If we were provided pre-merged tags (w/ the -m option), then don't
152# ever try to allocate one, just fail if we don't have a number
153
154for name, t in sorted(by_tagname.iteritems()):
155  if t.tagnum is None:
156    if pre_merged_tags:
157      try:
158        t.tagnum = pre_merged_tags[t.tagname]
159      except KeyError:
160        print >> sys.stderr, ("Error: Tag number not defined for tag `%s'."
161            +" Have you done a full build?") % t.tagname
162        sys.exit(1)
163    else:
164      while True:
165        x = (hashname(name) % (ASSIGN_LIMIT - ASSIGN_START - 1)) + ASSIGN_START
166        if x not in by_tagnum:
167          t.tagnum = x
168          by_tagnum[x] = t
169          break
170        name = "_" + name
171
172# by_tagnum should be complete now; we've assigned numbers to all tags.
173
174buffer = cStringIO.StringIO()
175for n, t in sorted(by_tagnum.iteritems()):
176  if t.description:
177    buffer.write("%d %s %s\n" % (t.tagnum, t.tagname, t.description))
178  else:
179    buffer.write("%d %s\n" % (t.tagnum, t.tagname))
180
181event_log_tags.WriteOutput(output_file, buffer)
182