Move patchparser to patchwork.parser

[patchwork] / apps / patchwork / parser.py

diff --git a/apps/patchwork/parser.py b/apps/patchwork/parser.py
new file mode 100644 (file)
index 0000000..16d1de4
--- /dev/null
+++ b/apps/patchwork/parser.py
@@ -0,0 +1,158 @@
+#!/usr/bin/python
+#
+# Patchwork - automated patch tracking system
+# Copyright (C) 2008 Jeremy Kerr <jk@ozlabs.org>
+#
+# This file is part of the Patchwork package.
+#
+# Patchwork is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# Patchwork is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Patchwork; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+
+import re
+
+def parse_patch(text):
+    patchbuf = ''
+    commentbuf = ''
+    buf = ''
+
+    # state specified the line we just saw, and what to expect next
+    state = 0
+    # 0: text
+    # 1: suspected patch header (diff, ====, Index:)
+    # 2: patch header line 1 (---)
+    # 3: patch header line 2 (+++)
+    # 4: patch hunk header line (@@ line)
+    # 5: patch hunk content
+    #
+    # valid transitions:
+    #  0 -> 1 (diff, ===, Index:)
+    #  0 -> 2 (---)
+    #  1 -> 2 (---)
+    #  2 -> 3 (+++)
+    #  3 -> 4 (@@ line)
+    #  4 -> 5 (patch content)
+    #  5 -> 1 (run out of lines from @@-specifed count)
+    #
+    # Suspected patch header is stored into buf, and appended to
+    # patchbuf if we find a following hunk. Otherwise, append to
+    # comment after parsing.
+
+    # line counts while parsing a patch hunk
+    lc = (0, 0)
+    hunk = 0
+
+    hunk_re = re.compile('^\@\@ -\d+(?:,(\d+))? \+\d+(?:,(\d+))? \@\@')
+
+    for line in text.split('\n'):
+        line += '\n'
+
+        if state == 0:
+            if line.startswith('diff') or line.startswith('===') \
+                    or line.startswith('Index: '):
+                state = 1
+                buf += line
+
+            elif line.startswith('--- '):
+                state = 2
+                buf += line
+
+            else:
+                commentbuf += line
+
+        elif state == 1:
+            buf += line
+            if line.startswith('--- '):
+                state = 2
+
+        elif state == 2:
+            if line.startswith('+++ '):
+                state = 3
+                buf += line
+
+            elif hunk:
+                state = 1
+                buf += line
+
+            else:
+                state = 0
+                commentbuf += buf + line
+                buf = ''
+
+        elif state == 3:
+            match = hunk_re.match(line)
+            if match:
+
+                def fn(x):
+                    if not x:
+                        return 1
+                    return int(x)
+
+                lc = map(fn, match.groups())
+
+                state = 4
+                patchbuf += buf + line
+                buf = ''
+
+            elif line.startswith('--- '):
+                patchbuf += buf + line
+                buf = ''
+                state = 2
+
+            elif hunk:
+                state = 1
+                buf += line
+
+            else:
+                state = 0
+                commentbuf += buf + line
+                buf = ''
+
+        elif state == 4 or state == 5:
+            if line.startswith('-'):
+                lc[0] -= 1
+            elif line.startswith('+'):
+                lc[1] -= 1
+            else:
+                lc[0] -= 1
+                lc[1] -= 1
+
+            patchbuf += line
+
+            if lc[0] <= 0 and lc[1] <= 0:
+                state = 3
+                hunk += 1
+            else:
+                state = 5
+
+        else:
+            raise Exception("Unknown state %d! (line '%s')" % (state, line))
+
+    commentbuf += buf
+
+    if patchbuf == '':
+        patchbuf = None
+
+    if commentbuf == '':
+        commentbuf = None
+
+    return (patchbuf, commentbuf)
+
+if __name__ == '__main__':
+    import sys
+    (patch, comment) = parse_patch(sys.stdin.read())
+    if patch:
+        print "Patch: ------\n" + patch
+    if comment:
+        print "Comment: ----\n" + comment