# HG changeset patch
# User Barry A. Scott <barry@barrys-emacs.org>
# Date 1477650800 -3600
# Node ID ff6efc1ab9e4ce6ecfa93a8a0d9f94ff287066ba
# Parent  c4c0efb37187b30b00561a23a18d94c07ffc3615
protocol: allow hglib user to get call backs for prompts, output and errors

setcbout(cbout), setcberr(cberr) and setcbprompt(cbprompt) are used to
set the call back function used by the hgclient class. cb stands for
call back.

cbout is a function that will be called with the stdout data of the
command as it runs. cbout is called with output as it is made available,
which can be as partial lines or multiple lines.

cberr is a function that will be called with the stderr data of the
command as it runs. cberr is called with output as it is made available,
which can be as partial lines or multiple lines.

Command that make remote connects can prompt for username and password
for HTTP/HTTPS connections.

cbprompt is called when hgclient need a response to a prompt from the
server. It receives the max number of bytes to return and the contents
of stdout received so far. The last text sent to either cbout or cberr
will contain the prompt text itself.

diff -r c4c0efb37187 -r ff6efc1ab9e4 hglib/client.py
--- a/hglib/client.py	Tue Oct 18 17:45:17 2016 +0100
+++ b/hglib/client.py	Fri Oct 28 11:33:20 2016 +0100
@@ -59,11 +59,42 @@
         # include the hidden changesets if True
         self.hidden = None
 
+        self._cbout = None
+        self._cberr = None
+        self._cbprompt = None
+
         if connect:
             self.open()
 
         self._protocoltracefn = None
 
+    def setcbout(self, cbout):
+        """
+        cbout is a function that will be called with the stdout data of
+        the command as it runs. Call with None to stop getting call backs.
+        """
+        self._cbout = cbout
+
+    def setcberr(self, cberr):
+        """
+        cberr is a function that will be called with the stderr data of
+        the command as it runs.Call with None to stop getting call backs.
+        """
+        self._cberr = cberr
+
+    def setcbprompt(self, cbprompt):
+        """
+        cbprompt is used to reply to prompts by the server
+        It receives the max number of bytes to return and the
+        contents of stdout received so far.
+
+        Call with None to stop getting call backs.
+
+        cbprompt is never called from merge() or import_()
+        which already handle the prompt.
+        """
+        self._cbprompt = cbprompt
+
     def setprotocoltrace(self, tracefn=None):
         """
         if tracefn is None no trace calls will be made.
@@ -180,9 +211,25 @@
         It receives the max number of bytes to return
         """
         out, err = BytesIO(), BytesIO()
-        outchannels = {b('o') : out.write, b('e') : err.write}
+        outchannels = {}
+        if self._cbout is None:
+            outchannels[b('o')] = out.write
+        else:
+            def out_handler(data):
+                out.write(data)
+                self._cbout(data)
+            outchannels[b('o')] = out_handler
+        if self._cberr is None:
+            outchannels[b('e')] = err.write
+        else:
+            def err_handler(data):
+                err.write(data)
+                self._cberr(data)
+            outchannels[b('e')] = err_handler
 
         inchannels = {}
+        if prompt is None:
+            prompt = self._cbprompt
         if prompt is not None:
             def func(size):
                 reply = prompt(size, out.getvalue())