Add a MealieReader class

4 files changed, 226 insertions, 0 deletions

diff --git a/meliaereader/__init__.py b/meliaereader/__init__.py
new file mode 100644
index 00000000..8cf0a0ac
--- /dev/null
+++ b/meliaereader/__init__.py
@@ -0,0 +1,19 @@
+# Copyright 2016  Lars Wirzenius
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# =*= License: GPL-3+ =*=
+
+
+from .reader import MeliaeReader
diff --git a/meliaereader/reader.py b/meliaereader/reader.py
new file mode 100644
index 00000000..a0a2f4eb
--- /dev/null
+++ b/meliaereader/reader.py
@@ -0,0 +1,76 @@
+# Copyright 2016  Lars Wirzenius
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# =*= License: GPL-3+ =*=
+
+
+import json
+
+
+class MeliaeReader(object):
+
+    def __init__(self):
+        self._objs = []
+
+    def __iter__(self):
+        return iter(self._objs)
+
+    def __contains__(self, ref):
+        return any(o['address'] == ref for o in self)
+
+    def __len__(self):
+        return len(self._objs)
+
+    def read(self, filename):
+        with open(filename) as f:
+            self._objs.extend(json.loads(line) for line in f)
+
+    def get_total_size(self):
+        return self.get_size(self._objs)
+
+    def get_size(self, objs):
+        return sum(o['size'] for o in objs)
+
+    def get_types(self):
+        return set(o['type'] for o in self)
+
+    def get_objs_of_type(self, typename):
+        return [o for o in self if o['type'] == typename]
+
+    def get_closure(self, obj):
+        closure = []
+        todo = [obj]
+        done = set()
+        while todo:
+            o = todo.pop(0)
+            done.add(o['address'])
+            closure.append(o)
+            for ref in o['refs']:
+                if ref not in done and ref in self:
+                    todo.append(self.get_object(ref))
+        return closure
+
+    def get_object(self, ref):
+        for obj in self:
+            if obj['address'] == ref:
+                return obj
+        raise Exception('No object with address {}'.format(ref))
+
+    def get_closure_of_type(self, typename):
+        type_closure = {}
+        for obj in self.get_objs_of_type(typename):
+            for o in self.get_closure(obj):
+                type_closure[o['address']] = o
+        return type_closure.values()
diff --git a/meliaereader/reader_tests.py b/meliaereader/reader_tests.py
new file mode 100644
index 00000000..c50e97c1
--- /dev/null
+++ b/meliaereader/reader_tests.py
@@ -0,0 +1,129 @@
+# Copyright 2016  Lars Wirzenius
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# =*= License: GPL-3+ =*=
+
+
+import json
+import os
+import shutil
+import tempfile
+import unittest
+
+import meliaereader
+
+
+class MeliaeReaderTests(unittest.TestCase):
+
+    def setUp(self):
+        self.tempdir = tempfile.mkdtemp()
+
+    def tearDown(self):
+        shutil.rmtree(self.tempdir)
+
+    def make_file(self, *objs):
+        fd, filename = tempfile.mkstemp(dir=self.tempdir)
+        os.close(fd)
+        with open(filename, 'w') as f:
+            for obj in objs:
+                f.write('{}\n'.format(json.dumps(obj)))
+        return filename
+
+    def make_object(self, **kwargs):
+        return kwargs
+
+    def test_has_no_objects_initially(self):
+        mr = meliaereader.MeliaeReader()
+        self.assertEqual(len(mr), 0)
+
+    def test_reads_an_empty_file(self):
+        mr = meliaereader.MeliaeReader()
+        mr.read('/dev/null')
+        self.assertEqual(len(mr), 0)
+
+    def test_reads_file_with_one_object(self):
+        filename = self.make_file(self.make_object())
+        mr = meliaereader.MeliaeReader()
+        mr.read(filename)
+        self.assertEqual(len(mr), 1)
+
+    def test_get_object_raises_exception_if_not_found(self):
+        mr = meliaereader.MeliaeReader()
+        self.assertRaises(Exception, mr.get_object, 1)
+
+    def test_get_object_returns_object_if_found(self):
+        obj = self.make_object(type='foo', address=1)
+        filename = self.make_file(obj)
+        mr = meliaereader.MeliaeReader()
+        mr.read(filename)
+        self.assertEqual(mr.get_object(obj['address']), obj)
+
+    def test_reports_total_size_correctly(self):
+        obj = self.make_object(type='foo', address=1, size=42)
+        filename = self.make_file(obj)
+        mr = meliaereader.MeliaeReader()
+        mr.read(filename)
+        self.assertEqual(mr.get_total_size(), 42)
+
+    def test_report_size_for_list_of_objects_correctly(self):
+        obj = self.make_object(type='foo', address=1, size=42)
+        filename = self.make_file(obj)
+        mr = meliaereader.MeliaeReader()
+        mr.read(filename)
+        self.assertEqual(mr.get_size([obj]), 42)
+
+    def test_readings_adds_to_existing_objs(self):
+        filename_1 = self.make_file(self.make_object())
+        filename_2 = self.make_file(self.make_object())
+        mr = meliaereader.MeliaeReader()
+        mr.read(filename_1)
+        mr.read(filename_2)
+        self.assertEqual(len(mr), 2)
+
+    def test_reports_object_types(self):
+        filename = self.make_file(self.make_object(type='foo'))
+        mr = meliaereader.MeliaeReader()
+        mr.read(filename)
+        self.assertEqual(mr.get_types(), set(['foo']))
+
+    def test_reports_objs_of_type(self):
+        obj_1 = self.make_object(type='foo')
+        obj_2 = self.make_object(type='bar')
+        filename = self.make_file(obj_1, obj_2)
+        mr = meliaereader.MeliaeReader()
+        mr.read(filename)
+        self.assertEqual(sorted(mr.get_types()), ['bar', 'foo'])
+        self.assertEqual(mr.get_objs_of_type('foo'), [obj_1])
+        self.assertEqual(mr.get_objs_of_type('bar'), [obj_2])
+        self.assertEqual(mr.get_objs_of_type('nonononono'), [])
+
+    def test_reports_closure_for_object(self):
+        obj_1 = self.make_object(type='foo', address=1, refs=[2])
+        obj_2 = self.make_object(type='bar', address=2, refs=[])
+        filename = self.make_file(obj_1, obj_2)
+        mr = meliaereader.MeliaeReader()
+        mr.read(filename)
+        self.assertEqual(mr.get_closure(obj_1), [obj_1, obj_2])
+        self.assertEqual(mr.get_closure(obj_2), [obj_2])
+
+    def test_reports_closure_for_type(self):
+        obj_1 = self.make_object(type='foo', address=1, refs=[2])
+        obj_2 = self.make_object(type='bar', address=2, refs=[])
+        filename = self.make_file(obj_1, obj_2)
+        mr = meliaereader.MeliaeReader()
+        mr.read(filename)
+        self.assertEqual(list(mr), [obj_1, obj_2])
+        self.assertEqual(mr.get_closure_of_type('foo'), [obj_1, obj_2])
+        self.assertEqual(mr.get_closure_of_type('bar'), [obj_2])
diff --git a/without-tests b/without-tests
index fc8b281c..66df6b0d 100644
--- a/without-tests
+++ b/without-tests
@@ -1,5 +1,7 @@
 setup.py
 
+meliaereader/__init__.py
+
 obnamlib/app.py
 obnamlib/backup_progress.py
 obnamlib/defaults.py