git-p4: use subprocess in p4CmdList

diff --git a/contrib/fast-import/git-p4 b/contrib/fast-import/git-p4
index d1f8d3b78d12c95e580750c3c0b02d54865f5da5..d93e6561554a1592afdc70833d9cac51d6ad55b6 100755 (executable)
--- a/contrib/fast-import/git-p4
+++ b/contrib/fast-import/git-p4
@@ -63,21 +63,34 @@ def system(cmd):
     if os.system(cmd) != 0:
         die("command failed: %s" % cmd)
 
-def p4CmdList(cmd):
+def p4CmdList(cmd, stdin=None, stdin_mode='w+b'):
     cmd = "p4 -G %s" % cmd
     if verbose:
         sys.stderr.write("Opening pipe: %s\n" % cmd)
-    pipe = os.popen(cmd, "rb")
+
+    # Use a temporary file to avoid deadlocks without
+    # subprocess.communicate(), which would put another copy
+    # of stdout into memory.
+    stdin_file = None
+    if stdin is not None:
+        stdin_file = tempfile.TemporaryFile(prefix='p4-stdin', mode=stdin_mode)
+        stdin_file.write(stdin)
+        stdin_file.flush()
+        stdin_file.seek(0)
+
+    p4 = subprocess.Popen(cmd, shell=True,
+                          stdin=stdin_file,
+                          stdout=subprocess.PIPE)
 
     result = []
     try:
         while True:
-            entry = marshal.load(pipe)
+            entry = marshal.load(p4.stdout)
             result.append(entry)
     except EOFError:
         pass
-    exitCode = pipe.close()
-    if exitCode != None:
+    exitCode = p4.wait()
+    if exitCode != 0:
         entry = {}
         entry["p4ExitCode"] = exitCode
         result.append(entry)
@@ -168,12 +181,12 @@ def gitBranchExists(branch):
 def gitConfig(key):
     return read_pipe("git config %s" % key, ignore_error=True).strip()
 
-def findUpstreamBranchPoint():
+def findUpstreamBranchPoint(head = "HEAD"):
     settings = None
     branchPoint = ""
     parent = 0
     while parent < 65535:
-        commit = "HEAD~%s" % parent
+        commit = head + "~%s" % parent
         log = extractLogMessageFromGitCommit(commit)
         settings = extractSettingsGitLog(log)
         if not settings.has_key("depot-paths"):
@@ -700,6 +713,7 @@ class P4Sync(Command):
                     if branch not in branches:
                         branches[branch] = []
                     branches[branch].append(file)
+                    break
 
         return branches
 
@@ -716,7 +730,11 @@ class P4Sync(Command):
         # POSIX says it's 4096 bytes, default for Linux seems to be 130 K.
         # and all OS from the table below seems to be higher than POSIX.
         # See http://www.in-ulm.de/~mascheck/various/argmax/
-        argmax = min(4000, os.sysconf('SC_ARG_MAX'))
+        if (self.isWindows):
+            argmax = 2000
+        else:
+            argmax = min(4000, os.sysconf('SC_ARG_MAX'))
+
         chunk = ''
         filedata = []
         for i in xrange(len(files)):
@@ -938,6 +956,8 @@ class P4Sync(Command):
             return p
 
     def getBranchMapping(self):
+        lostAndFoundBranches = set()
+
         for info in p4CmdList("branches"):
             details = p4Cmd("branch -o %s" % info["branch"])
             viewIdx = 0
@@ -953,10 +973,23 @@ class P4Sync(Command):
                 if source.startswith(self.depotPaths[0]) and destination.startswith(self.depotPaths[0]):
                     source = source[len(self.depotPaths[0]):-4]
                     destination = destination[len(self.depotPaths[0]):-4]
-                    if destination not in self.knownBranches:
-                        self.knownBranches[destination] = source
+
+                    if destination in self.knownBranches:
+                        if not self.silent:
+                            print "p4 branch %s defines a mapping from %s to %s" % (info["branch"], source, destination)
+                            print "but there exists another mapping from %s to %s already!" % (self.knownBranches[destination], destination)
+                        continue
+
+                    self.knownBranches[destination] = source
+
+                    lostAndFoundBranches.discard(destination)
+
                     if source not in self.knownBranches:
-                        self.knownBranches[source] = source
+                        lostAndFoundBranches.add(source)
+
+
+        for branch in lostAndFoundBranches:
+            self.knownBranches[branch] = branch
 
     def listExistingP4GitBranches(self):
         self.p4BranchesInGit = []
@@ -1449,6 +1482,31 @@ class P4Clone(P4Sync):
 
         return True
 
+class P4Branches(Command):
+    def __init__(self):
+        Command.__init__(self)
+        self.options = [ ]
+        self.description = ("Shows the git branches that hold imports and their "
+                            + "corresponding perforce depot paths")
+        self.verbose = False
+
+    def run(self, args):
+        cmdline = "git rev-parse --symbolic "
+        cmdline += " --remotes"
+
+        for line in read_pipe_lines(cmdline):
+            line = line.strip()
+
+            if not line.startswith('p4/') or line == "p4/HEAD":
+                continue
+            branch = line
+
+            log = extractLogMessageFromGitCommit("refs/remotes/%s" % branch)
+            settings = extractSettingsGitLog(log)
+
+            print "%s <= %s (%s)" % (branch, ",".join(settings["depot-paths"]), settings["change"])
+        return True
+
 class HelpFormatter(optparse.IndentedHelpFormatter):
     def __init__(self):
         optparse.IndentedHelpFormatter.__init__(self)
@@ -1473,7 +1531,8 @@ commands = {
     "sync" : P4Sync,
     "rebase" : P4Rebase,
     "clone" : P4Clone,
-    "rollback" : P4RollBack
+    "rollback" : P4RollBack,
+    "branches" : P4Branches
 }