add module to parse mtree output that is compatible w/ bsdtar..

ui/Makefile

@@ -1,6 +1,6 @@
-test: fixtures/sample.data.pasn1
+test: fixtures/sample.data.pasn1 fixtures/sample.mtree
 	(. ./p/bin/activate && \
-		(echo cli.py | entr sh -c 'python -m coverage run -m unittest cli && coverage report -m --omit=p/\*'))
+		(ls cli.py mtree.py | entr sh -c 'python -m coverage run -m unittest cli mtree && coverage report -m --omit=p/\*'))
 
 env:
 	virtualenv p
@@ -9,3 +9,6 @@ env:
 
 fixtures/sample.data.pasn1: fixtures/genfixtures.py
 	(. ./p/bin/activate && cd fixtures && PYTHONPATH=.. python genfixtures.py )
+
+fixtures/sample.mtree: fixtures/mtree.dir
+	bsdtar -cf - --format mtree --options='!all,time,sha512,size,indent' -C fixtures/mtree.dir . > $@

ui/fixtures/mtree.dir/test.txt

@@ -0,0 +1 @@
+this is a test

ui/fixtures/sample.mtree

@@ -0,0 +1,7 @@
+#mtree
+.               time=1567323634.0
+./\134\040\015\012\134*\134?\134['\012 \
+                time=1567323609.0 size=0 \
+                sha512digest=cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e
+./test.txt      time=1567323634.0 size=15 \
+                sha512digest=7d5768d47b6bc27dc4fa7e9732cfa2de506ca262a2749cb108923e5dddffde842bbfee6cb8d692fb43aca0f12946c521cce2633887914ca1f96898478d10ad3f

ui/mtree.py

@@ -0,0 +1,87 @@
+#!/usr/bin/env python
+
+import unittest
+
+def _destrvis(s):
+	r = []
+	state = 0
+	for i in s:
+		if state == 0:
+			if i == '\\':
+				state = 1
+				v = 0
+			else:
+				r.append(i)
+		elif state in (1, 2):
+			v = v * 8 + int(i)
+			state += 1
+		elif state == 3:
+			v = v * 8 + int(i)
+			r.append(chr(v))
+			state = 0
+			
+	return ''.join(r)
+
+def parse(fname):
+	with open(fname) as fp:
+		i = fp.readline().strip()
+		if not i.startswith('#mtree'):
+			raise ValueError('not an mtree file')
+
+		path = []
+		res = {}
+
+		while True:
+			i = fp.readline().strip()
+
+			# don't believe the bsdtar mtree output
+			# contains the cases marked below
+			if not i:
+				break
+			elif i.startswith('#'):	# pragma: no cover
+				raise NotImplementedError
+			elif i.startswith('/set'):	# pragma: no cover
+				raise NotImplementedError
+			elif i.startswith('/unset'):	# pragma: no cover
+				raise NotImplementedError
+
+			parts = i.split()
+			fname = parts.pop(0)
+			while parts[-1] == '\\':
+				del parts[-1]
+				parts.extend(fp.readline().strip().split())
+
+			res[fname] = dict(x.split('=') for x in parts)
+
+		return res
+
+class Test(unittest.TestCase):
+	def test_parsemtree(self):
+		self.assertRaises(ValueError, parse, 'fixtures/genfixtures.py')
+
+		data = parse('fixtures/sample.mtree')
+
+		proof = {
+			'.': {
+				'time': '1567323634.0'
+			},
+			"./\\134\\040\\015\\012\\134*\\134?\\134['\\012": {
+				'size': '0',
+				'sha512digest': 'cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e',
+				'time': '1567323609.0'
+			},
+			'./test.txt': {
+				'size': '15',
+				'sha512digest': '7d5768d47b6bc27dc4fa7e9732cfa2de506ca262a2749cb108923e5dddffde842bbfee6cb8d692fb43aca0f12946c521cce2633887914ca1f96898478d10ad3f',
+				'time': '1567323634.0'
+			},
+		}
+
+		self.assertEqual(data, proof)
+
+	def test_debsstr(self):
+		self.assertEqual(_destrvis(r'\015'), '\r')
+		self.assertEqual(_destrvis(r'\011'), '\t')
+		self.assertEqual(_destrvis(
+		    "./\\134\\040\\015\\012\\134*\\134?\\134['\\012"),
+		    "./\134\040\015\012\134*\134?\134['\012")