From: Zac Medico <zmedico@gentoo.org>
Date: Sat, 5 Jan 2013 15:18:05 +0000 (-0800)
Subject: Add async FileDigester class.
X-Git-Tag: v2.2.0_alpha150~33
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=99ca26fb15414379ae3a70cc446a225f2b8d532b;p=portage.git

Add async FileDigester class.
---

diff --git a/pym/portage/util/_async/FileDigester.py b/pym/portage/util/_async/FileDigester.py
new file mode 100644
index 000000000..881c69280
--- /dev/null
+++ b/pym/portage/util/_async/FileDigester.py
@@ -0,0 +1,73 @@
+# Copyright 2013 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+
+from portage import os
+from portage.checksum import perform_multiple_checksums
+from portage.util._async.ForkProcess import ForkProcess
+from _emerge.PipeReader import PipeReader
+
+class FileDigester(ForkProcess):
+	"""
+	Asynchronously generate file digests. Pass in file_path and
+	hash_names, and after successful execution, the digests
+	attribute will be a dict containing all of the requested
+	digests.
+	"""
+
+	__slots__ = ('file_path', 'digests', 'hash_names',
+		'_digest_pipe_reader', '_digest_pw')
+
+	def _start(self):
+		pr, pw = os.pipe()
+		self.fd_pipes = {}
+		self.fd_pipes[pw] = pw
+		self._digest_pw = pw
+		self._digest_pipe_reader = PipeReader(
+			input_files={"input":pr},
+			scheduler=self.scheduler)
+		self._digest_pipe_reader.addExitListener(self._digest_pipe_reader_exit)
+		self._digest_pipe_reader.start()
+		ForkProcess._start(self)
+		os.close(pw)
+
+	def _run(self):
+		digests = perform_multiple_checksums(self.file_path,
+			hashes=self.hash_names)
+
+		buf = "".join("%s=%s\n" % item
+			for item in digests.items()).encode('utf_8')
+
+		while buf:
+			buf = buf[os.write(self._digest_pw, buf):]
+
+		return os.EX_OK
+
+	def _parse_digests(self, data):
+
+		digests = {}
+		for line in data.decode('utf_8').splitlines():
+			parts = line.split('=', 1)
+			if len(parts) == 2:
+				digests[parts[0]] = parts[1]
+
+		self.digests = digests
+
+	def _pipe_logger_exit(self, pipe_logger):
+		# Ignore this event, since we want to ensure that we
+		# exit only after _digest_pipe_reader has reached EOF.
+		self._pipe_logger = None
+
+	def _digest_pipe_reader_exit(self, pipe_reader):
+		self._parse_digests(pipe_reader.getvalue())
+		self._digest_pipe_reader = None
+		self._unregister()
+		self.wait()
+
+	def _unregister(self):
+		ForkProcess._unregister(self)
+
+		pipe_reader = self._digest_pipe_reader
+		if pipe_reader is not None:
+			self._digest_pipe_reader = None
+			pipe_reader.removeExitListener(self._digest_pipe_reader_exit)
+			pipe_reader.cancel()