From 01a036ff09bc7c283a89b23c7e24d7a33d7a4ed7 Mon Sep 17 00:00:00 2001
From: Thomas Leonard <talex5@gmail.com>
Date: Fri, 31 Oct 2003 13:22:54 +0000
Subject: [PATCH] Simplified implementation of saving.SaveFilter by using the
 new processes.PipeThroughCommand class. The child_run() method of SaveFilter
 is no longer supported. In processes.PipeThroughCommand, a None input stream
 gets /dev/null instead of inheriting its parent's stream. The class has a new
 run_child_with_streams to make overriding the behaviour easier.

git-svn-id: https://rox.svn.sourceforge.net/svnroot/rox/trunk/ROX-Lib2@3211 66de3db3-b00d-0410-b41b-f4738ad19bea
---
 Help/Changes            |  9 +++++++
 python/rox/processes.py | 19 ++++++++++----
 python/rox/saving.py    | 69 ++++---------------------------------------------
 3 files changed, 28 insertions(+), 69 deletions(-)

diff --git a/Help/Changes b/Help/Changes
index 233bf2e..caa4d51 100644
--- a/Help/Changes
+++ b/Help/Changes
@@ -3,6 +3,15 @@
 			by Thomas Leonard
 			http://rox.sourceforge.net
 
+31-Oct-2003
+~~~~~~~~~~~
+Simplified implementation of saving.SaveFilter by using the new
+processes.PipeThroughCommand class. The child_run() method of SaveFilter
+is no longer supported.
+In processes.PipeThroughCommand, a None input stream gets /dev/null instead
+of inheriting its parent's stream. The class has a new run_child_with_streams
+to make overriding the behaviour easier.
+
 29-Oct-2003
 ~~~~~~~~~~~
 Changed 'Dismiss' to 'Close' (Chris Shaffer).
diff --git a/python/rox/processes.py b/python/rox/processes.py
index 38adda2..15f6fd9 100644
--- a/python/rox/processes.py
+++ b/python/rox/processes.py
@@ -222,23 +222,32 @@ class PipeThroughCommand(Process):
 		self.tmp_stream = None
 
 	def child_run(self):
-		src = self.src
+		"""Assigns file descriptors and calls child_run_with_streams."""
+		src = self.src or file('/dev/null', 'r')
 
-		if src:
-			os.dup2(src.fileno(), 0)
-			_keep_on_exec(0)
+		os.dup2(src.fileno(), 0)
+		_keep_on_exec(0)
+		try:
 			os.lseek(0, 0, 0)	# OpenBSD needs this, dunno why
+		except:
+			pass
+
 		if self.dst:
 			os.dup2(self.tmp_stream.fileno(), 1)
 			_keep_on_exec(1)
 	
+		self.child_run_with_streams()
+		os._exit(1)
+	
+	def child_run_with_streams(self):
+		"""This is run by the child process. stdin and stdout have already been set up.
+		Should call exec() or os._exit() to finish. Default method execs self.command."""
 		# (basestr is python2.3 only)
 		if isinstance(self.command, str):
 			if os.system(self.command) == 0:
 				os._exit(0)	# No error code or signal
 		else:
 			os.execvp(self.command[0], self.command)
-		os._exit(1)
 	
 	def parent_post_fork(self):
 		if self.dst and self.tmp_stream is self.dst:
diff --git a/python/rox/saving.py b/python/rox/saving.py
index c983f8d..a441a30 100644
--- a/python/rox/saving.py
+++ b/python/rox/saving.py
@@ -561,72 +561,13 @@ class SaveFilter(Saveable):
 			self.stdin = None
 	
 	def save_to_stream(self, stream):
-		from processes import Process
-		from cStringIO import StringIO
-		errors = StringIO()
-		done = []
+		from processes import PipeThroughCommand
 
-		# Get the FD for the output, creating a tmp file if needed
-		if hasattr(stream, 'fileno'):
-			stdout_fileno = stream.fileno()
-			tmp = None
-		else:
-			import tempfile
-			tmp = tempfile.TemporaryFile()
-			stdout_fileno = tmp.fileno()
-
-		# Get the FD for the input
-		if self.stdin:
-			stdin_fileno = self.stdin.fileno()
-			self.stdin.seek(0)
-		else:
-			stdin_fileno = os.open('/dev/null', os.O_RDONLY)
-			
-		class FilterProcess(Process):
-			def child_post_fork(self):
-				if stdout_fileno != 1:
-					os.dup2(stdout_fileno, 1)
-					os.close(stdout_fileno)
-				if stdin_fileno is not None and stdin_fileno != 0:
-					os.dup2(stdin_fileno, 0)
-					os.close(stdin_fileno)
-			def got_error_output(self, data):
-				errors.write(data)
-			def child_died(self, status):
-				done.append(status)
-				g.mainquit()
-			def child_run(proc):
-				self.child_run()
-		self.process = FilterProcess()
-		self.killed = 0
-		self.process.start()
-		while not done:
-			g.mainloop()
+		assert not hasattr(self, 'child_run')	# No longer supported
+
+		self.process = PipeThroughCommand(self.command, self.stdin, stream)
+		self.process.wait()
 		self.process = None
-		status = done[0]
-		if self.killed:
-			print >> errors, '\nProcess terminated at user request'
-		error = errors.getvalue().strip()
-		if error:
-			raise AbortSave(error)
-		if status:
-			raise AbortSave('child_run() returned an error code, but no error message!')
-		if tmp:
-			# Data went to a temp file
-			tmp.seek(0)
-			stream.write(tmp.read())
-
-	def child_run(self):
-		"""This is run in the child process. The default method runs 'self.command'
-		using os.system() and prints a message to stderr if the exit code is non-zero.
-		DO NOT call gtk functions here!
-
-		Be careful to escape shell special characters when inserting filenames!
-		"""
-		command = self.command
-		if os.system(command):
-			print >>sys.stderr, "Command:\n%s\nreturned an error code" % command
-		os._exit(0)	# Writing to stderr indicates error...
 	
 	def save_cancelled(self):
 		"""Send SIGTERM to the child processes."""
-- 
2.11.4.GIT