From 333dd4c0fd75240be5f0329c837d8effdf705d67 Mon Sep 17 00:00:00 2001
From: Brian Harring <ferringb@google.com>
Date: Mon, 15 Oct 2012 23:13:53 -0700
Subject: ongoing work

---
 rewrite-commit-dump.py | 123 ++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 97 insertions(+), 26 deletions(-)

diff --git a/rewrite-commit-dump.py b/rewrite-commit-dump.py
index 4784cb5..7678406 100755
--- a/rewrite-commit-dump.py
+++ b/rewrite-commit-dump.py
@@ -2,6 +2,7 @@
 import functools
 import re
 import sys
+from collections import namedtuple
 
 mangler = []
 mangler.append(functools.partial(
@@ -11,29 +12,99 @@ mangler.append(functools.partial(
   re.compile(r"^\(portage version: (.*)\)$", re.M|re.I).sub,
     r"Package-Manager: portage-\1"))
 
-write = sys.stdout.write
-source = open(sys.argv[1]) if len(sys.argv) > 1 else sys.stdin
-write('reset refs/heads/master\n')
-while True:
-  x = source.readline()
-  if not x:
-    break
-  chunked = x.split()
-  if not chunked:
-    write(x)
-    continue
-  elif chunked[0] in ('reset', 'from'):
-    continue
-  elif chunked[0] == 'commit':
-    write('commit refs/heads/master\n')
-    continue
-  elif chunked[0] != 'data':
-    write(x)
-    continue
-  assert len(chunked) == 2
-  size = int(chunked[1])
-  data = source.read(size)
-  assert len(data) == size
-  for func in mangler:
-    data = func(data)
-  write("data %i\n%s" % (len(data), data))
+fields = ('mark', 'author', 'committer', 'msg', 'files')
+record = namedtuple('record', fields)
+
+def deserialize_records(source):
+  line = source.readline()
+  while line:
+    while line.split()[0] in ('reset', 'progress'):
+      line = source.readline()
+
+    # First get the free form fields; stop after we get the commit msg.
+    assert line.split()[0] == 'commit', line
+    d = {}
+    while True:
+      line = source.readline()
+      chunks = line.split(None, 1)
+      assert len(chunks) == 2, line
+      if chunks[0] == 'from':
+        continue
+      assert chunks[0] in ('mark', 'author', 'committer', 'data')
+      if chunks[0] != 'data':
+        d[chunks[0]] = chunks[1].strip()
+        continue
+      # Process the commit message...
+      size = int(chunks[1])
+      data = source.read(size)
+      assert len(data) == size, (line, data)
+      for func in mangler:
+        data = func(data)
+      d['msg'] = data
+      line = source.readline()
+      # Note that cvs2git writes slightly funky data statements; the byte count
+      # doesn't necessarily include the trailing newline.
+      if line == '\n':
+        line = source.readline()
+      break
+
+    assert line
+    # From can show up here on occasion... annoying.
+    if line.split()[0:1] == ['from']:
+      line = source.readline()
+    files = {}
+    while line != '\n':
+      # Two types I can spot; M=modify, and D=delete.
+      assert line[-1] == '\n'
+      line = line[:-1]
+      mode = line.split(None, 1)
+      assert len(mode) == 2, line
+      if mode[0] == 'D':
+        files[mode[1]] = (mode[0], line)
+      elif mode[0] == 'M':
+        # M 100644 e8b9ed651c6209820779382edee2537209aba4ae dev-cpp/gtkmm/ChangeLog
+        chunks = mode[1].split(None, 3)
+        assert len(chunks) == 3, line
+        files[chunks[2]] = (mode[0], line)
+      else:
+        raise AssertionError("got unknown file op: mode=%r, line:\n%r" % (mode[0], line))
+      line = source.readline()
+    d['files'] = files
+    # Basic sanity check for the code above...
+    assert set(fields).issuperset(d), d
+    yield record(*[d.get(x) for x in fields])
+    # Bleh... of course namedtuple doesn't make this easy.
+    line = source.readline()
+
+def serialize_records(records, handle, target='refs/heads/master', progress=1000):
+  write = handle.write
+  write('reset %s\n' % target)
+  total = len(records)
+  for idx, record in enumerate(records, 1):
+    if idx % progress == 0:
+      write('progress %02.1f%%: %i of %i commits\n'
+        % ((100 * float(idx))//total, idx, total))
+    write('commit %s\n' % target)
+    # fields = ('mark', 'author', 'committer', 'msg', 'files')
+    for name, value in zip(fields, record):
+      if name == 'files':
+        for filename in sorted(value):
+          write("%s\n" % (value[filename][1],))
+      elif name in ('mark', 'author', 'committer'):
+        write("%s %s\n" % (name, value))
+      elif name == 'msg':
+        write("data %i\n%s" % (len(value), value))
+      else:
+        raise AssertionError("serialize is out of sync; don't know field %s" % name)
+    write("\n")
+
+def main(argv):
+  source = open(argv[0], 'r') if argv else sys.stdin
+  records = list(deserialize_records(source))
+  serialize_records(records, sys.stdout)
+  return 0
+
+if __name__ == '__main__':
+  if len(sys.argv) not in (1, 2):
+    raise SystemExit("args must be either none, or path to fast-export stream to read", code=1)
+  sys.exit(main(sys.argv[1:]))
-- 
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