From cd537fa3dda69ea256051b12de1b417b834b9f1c Mon Sep 17 00:00:00 2001
From: Paulo Madeira <acelent@gmail.com>
Date: Wed, 22 Jun 2011 00:16:31 +0100
Subject: [PATCH] Launch a reader thread in Win32 to implement can_read().

---
 dulwich/client.py |   86 +++++++++++++++++++++++++++++++++++++++++++++++++----
 1 files changed, 80 insertions(+), 6 deletions(-)

diff --git a/dulwich/client.py b/dulwich/client.py
index 1e72543..75ab4ad 100644
--- a/dulwich/client.py
+++ b/dulwich/client.py
@@ -308,6 +308,72 @@ class SubprocessWrapper(object):
         self.proc.wait()
 
 
+class SubprocessWrapperThread(object):
+    def __init__(self, proc):
+        import threading
+
+        self.proc = proc
+        self.cv = threading.Condition()
+        self.eof = False
+        self.read_buffer = ''
+        self.to_read = 1
+
+        self.thread = threading.Thread(target=self.read_ahead)
+        self.thread.daemon = True
+        self.thread.start()
+
+    def read_ahead(self):
+        to_read = 1
+        while True:
+            data = self.proc.stdout.read(to_read)
+            with self.cv:
+                self.read_buffer = data
+                self.cv.notify()
+                if data == '':
+                    self.eof = True
+                    break
+                self.cv.wait()
+                to_read = self.to_read
+
+    def read(self, size):
+        data = ''
+        while self.thread.is_alive():
+            with self.cv:
+                if self.read_buffer == '' and not self.eof:
+                    self.cv.wait()
+                if self.read_buffer == '':
+                    break
+                elif len(self.read_buffer) > size:
+                    data += self.read_buffer[:size]
+                    self.read_buffer = self.read_buffer[size:]
+                    break
+                else:
+                    data += self.read_buffer
+                    size -= len(self.read_buffer)
+                    self.read_buffer = ''
+                    self.to_read = max(1, size)
+                    self.cv.notify()
+                    if size == 0:
+                        break
+        return data
+
+    def write(self, data):
+        return self.proc.stdin.write(data)
+
+    def can_read(self):
+        with self.cv:
+            return self.read_buffer != ''
+
+    def close(self):
+        self.proc.stdin.close()
+        self.proc.stdout.close()
+        if self.thread.is_alive():
+            with self.cv:
+                self.to_read = 0
+                self.cv.notify()
+            self.thread.join()
+
+
 class SubprocessGitClient(GitClient):
     """Git client that talks to a server using a subprocess."""
 
@@ -316,11 +382,16 @@ class SubprocessGitClient(GitClient):
         GitClient.__init__(self, *args, **kwargs)
 
     def _connect(self, service, path):
-        import subprocess
+        import subprocess, sys
         argv = ['git', service, path]
-        p = SubprocessWrapper(
-            subprocess.Popen(argv, bufsize=0, stdin=subprocess.PIPE,
-                             stdout=subprocess.PIPE))
+        proc = subprocess.Popen(argv,
+                                bufsize=0,
+                                stdin=subprocess.PIPE,
+                                stdout=subprocess.PIPE)
+        if sys.platform == 'win32':
+            p = SubprocessWrapperThread(proc)
+        else:
+            p = SubprocessWrapper(proc)
         return Protocol(p.read, p.write,
                         report_activity=self._report_activity), p.can_read
 
@@ -328,7 +399,7 @@ class SubprocessGitClient(GitClient):
 class SSHVendor(object):
 
     def connect_ssh(self, host, command, username=None, port=None):
-        import subprocess
+        import subprocess, sys
         #FIXME: This has no way to deal with passwords..
         args = ['ssh', '-x']
         if port is not None:
@@ -339,7 +410,10 @@ class SSHVendor(object):
         proc = subprocess.Popen(args + command,
                                 stdin=subprocess.PIPE,
                                 stdout=subprocess.PIPE)
-        return SubprocessWrapper(proc)
+        if sys.platform == 'win32':
+            return SubprocessWrapperThread(proc)
+        else:
+            return SubprocessWrapper(proc)
 
 # Can be overridden by users
 get_ssh_vendor = SSHVendor
-- 
1.7.4.msysgit.0