darcs2hg: pause and resume support, date extraction from commit hash, does not break on empty commits

contrib/darcs2hg.py

@@ -1,131 +1,178 b''
 #!/usr/bin/env python
 # Encoding: iso-8859-1
 # vim: tw=80 ts=4 sw=4 noet
 # -----------------------------------------------------------------------------
 # Project   : Basic Darcs to Mercurial conversion script
 # -----------------------------------------------------------------------------
-# Author    : Sebastien Pierre <[e-mail]>
+# Authors   : Sebastien Pierre                           <[e-mail]>
+#             TK Soh                                      <[e-mail]>
+# -----------------------------------------------------------------------------
 # Creation  : 24-May-2006
-# Last mod  : 26-May-2006
-# History   :
-#             26-May-2006 - Updated
-#             24-May-2006 - First implementation
+# Last mod  : 05-Jun-2006
 # -----------------------------------------------------------------------------
 
 import os, sys
 import tempfile
 import xml.dom.minidom as xml_dom
 from time import strptime, mktime
 
 DARCS_REPO = None
 HG_REPO    = None
 
 USAGE = """\
-%s DARCSREPO HGREPO
+%s DARCSREPO HGREPO [SKIP]
 
     Converts the given Darcs repository to a new Mercurial repository. The given
     HGREPO must not exist, as it will be created and filled up (this will avoid
     overwriting valuable data.
 
+    In case an error occurs within the process, you can resume the process by
+    giving the last successfuly applied change number.
 """ % (os.path.basename(sys.argv[0]))
 
 # ------------------------------------------------------------------------------
 #
 # Utilities
 #
 # ------------------------------------------------------------------------------
 
-def cmd(text, path=None):
+def cmd(text, path=None, silent=False):
 	"""Executes a command, in the given directory (if any), and returns the
 	command result as a string."""
 	cwd = None
 	if path:
 		path = os.path.abspath(path)
 		cwd  = os.getcwd()
 		os.chdir(path)
-	print text
+	if not silent: print "> ", text
 	res = os.popen(text).read()
 	if path:
 		os.chdir(cwd)
 	return res
 
 def writefile(path, data):
 	"""Writes the given data into the given file."""
 	f = file(path, "w") ; f.write(data)  ; f.close()
 
+def error( *args ):
+	sys.stderr.write("ERROR: ")
+	for a in args: sys.stderr.write(str(a))
+	sys.stderr.write("\n")
+	sys.stderr.write("You can make manual fixes if necessary and then resume by"
+	" giving the last changeset number")
+	sys.exit(-1)
+
 # ------------------------------------------------------------------------------
 #
 # Darcs interface
 #
 # ------------------------------------------------------------------------------
 
 def darcs_changes(darcsRepo):
 	"""Gets the changes list from the given darcs repository. This returns the
 	chronological list of changes as (change name, change summary)."""
 	changes    = cmd("darcs changes --reverse --xml-output", darcsRepo)
 	doc        = xml_dom.parseString(changes)
-	res        = []
 	for patch_node in doc.childNodes[0].childNodes:
 		name = filter(lambda n:n.nodeName == "name", patch_node.childNodes)
 		comm = filter(lambda n:n.nodeName == "comment", patch_node.childNodes)
 		if not name:continue
 		else: name = name[0].childNodes[0].data
 		if not comm: comm = ""
 		else: comm = comm[0].childNodes[0].data
 		author = patch_node.getAttribute("author")
-		date = patch_node.getAttribute("date")
-        hash = patch_node.getAttribute("hash")
-        yield hash, author, date, name, comm
+		date   = patch_node.getAttribute("date")
+		chash  = os.path.splitext(patch_node.getAttribute("hash"))[0]
+		yield author, date, name, chash, comm
 
-def darcs_pull(hg_repo, darcs_repo, change):
-	cmd("darcs pull '%s' --all --patches='%s'" % (darcs_repo, change), hg_repo)
+def darcs_tip(darcs_repo):
+	changes = cmd("darcs changes",darcs_repo,silent=True)
+	changes = filter(lambda l:l.strip().startswith("* "), changes.split("\n"))
+	return len(changes)
+
+def darcs_pull(hg_repo, darcs_repo, chash):
+	old_tip = darcs_tip(darcs_repo)
+	res     = cmd("darcs pull '%s' --all --match='hash %s'" % (darcs_repo, chash), hg_repo)
+	print res
+	new_tip = darcs_tip(darcs_repo)
+	if not new_tip != old_tip + 1:
+		error("Darcs pull did not work as expected: " + res)
 
 # ------------------------------------------------------------------------------
 #
 # Mercurial interface
 #
 # ------------------------------------------------------------------------------
 
 def hg_commit( hg_repo, text, author, date ):
 	fd, tmpfile = tempfile.mkstemp(prefix="darcs2hg_")
 	writefile(tmpfile, text)
+	old_tip = hg_tip(hg_repo)
 	cmd("hg add -X _darcs", hg_repo)
 	cmd("hg remove -X _darcs --after", hg_repo)
-	cmd("hg commit -l %s -u '%s' -d '%s 0'"  % (tmpfile, author, date), hg_repo)
+	res = cmd("hg commit -l %s -u '%s' -d '%s 0'"  % (tmpfile, author, date), hg_repo)
 	os.unlink(tmpfile)
+	new_tip = hg_tip(hg_repo)
+	if not new_tip == old_tip + 1:
+		# Sometimes we may have empty commits, we simply skip them
+		if res.strip().lower().find("nothing changed") != -1:
+			pass
+		else:
+			error("Mercurial commit did not work as expected: " + res)
+
+def hg_tip( hg_repo ):
+	"""Returns the latest local revision number in the given repository."""
+	tip = cmd("hg tip", hg_repo, silent=True)
+	tip = tip.split("\n")[0].split(":")[1].strip()
+	return int(tip)
 
 # ------------------------------------------------------------------------------
 #
 # Main
 #
 # ------------------------------------------------------------------------------
 
 if __name__ == "__main__":
 	args = sys.argv[1:]
 	# We parse the arguments
 	if len(args)   == 2:
 		darcs_repo = os.path.abspath(args[0])
 		hg_repo    = os.path.abspath(args[1])
+		skip       = None
+	elif len(args) == 3:
+		darcs_repo = os.path.abspath(args[0])
+		hg_repo    = os.path.abspath(args[1])
+		skip       = int(args[2])
 	else:
 		print USAGE
 		sys.exit(-1)
 	# Initializes the target repo
 	if not os.path.isdir(darcs_repo + "/_darcs"):
-		print "No darcs directory found at: " + darc_repo
+		print "No darcs directory found at: " + darcs_repo
 		sys.exit(-1)
 	if not os.path.isdir(hg_repo):
 		os.mkdir(hg_repo)
-	else:
-		print "Given HG repository must not exist. It will be created"
+	elif skip == None:
+		print "Given HG repository must not exist when no SKIP is specified."
 		sys.exit(-1)
-	cmd("hg init '%s'" % (hg_repo))
-	cmd("darcs initialize", hg_repo)
+	if skip == None:
+		cmd("hg init '%s'" % (hg_repo))
+		cmd("darcs initialize", hg_repo)
 	# Get the changes from the Darcs repository
-	for hash, author, date, summary, description in darcs_changes(darcs_repo):
-		text = summary + "\n" + description
-		darcs_pull(hg_repo, darcs_repo, hash)
-		epoch = int(mktime(strptime(date, '%Y%m%d%H%M%S')))
-		hg_commit(hg_repo, text, author, epoch)
+	change_number = 0
+	for author, date, summary, chash, description in darcs_changes(darcs_repo):
+		print "== changeset", change_number,
+		if skip != None and change_number <= skip:
+			print "(skipping)"
+		else:
+			text = summary + "\n" + description
+			darcs_pull(hg_repo, darcs_repo, chash)
+			# The commit hash has a date like 20021020201112
+			# --------------------------------YYYYMMDDHHMMSS
+			date = chash.split("-")[0]
+			epoch = int(mktime(strptime(date, '%Y%m%d%H%M%S')))
+			hg_commit(hg_repo, text, author, epoch)
+		change_number += 1
+	print "Darcs repository (_darcs) was not deleted. You can keep or remove it."
 
 # EOF
-