diff options
Diffstat (limited to 'tests')
| -rwxr-xr-x | tests/qemu-iotests/040 | 283 | ||||
| -rw-r--r-- | tests/qemu-iotests/040.out | 4 | ||||
| -rwxr-xr-x | tests/qemu-iotests/041 | 138 | ||||
| -rw-r--r-- | tests/qemu-iotests/041.out | 4 | ||||
| -rwxr-xr-x | tests/qemu-iotests/155 | 7 | ||||
| -rwxr-xr-x | tests/qemu-iotests/244 | 14 | ||||
| -rw-r--r-- | tests/qemu-iotests/244.out | 6 | ||||
| -rw-r--r-- | tests/qemu-iotests/iotests.py | 59 |
8 files changed, 488 insertions, 27 deletions
diff --git a/tests/qemu-iotests/040 b/tests/qemu-iotests/040 index 2e7ee0e84f..32c82b4ec6 100755 --- a/tests/qemu-iotests/040 +++ b/tests/qemu-iotests/040 @@ -430,6 +430,289 @@ class TestReopenOverlay(ImageCommitTestCase): def test_reopen_overlay(self): self.run_commit_test(self.img1, self.img0) +class TestErrorHandling(iotests.QMPTestCase): + image_len = 2 * 1024 * 1024 + + def setUp(self): + iotests.create_image(backing_img, self.image_len) + qemu_img('create', '-f', iotests.imgfmt, '-o', 'backing_file=%s' % backing_img, mid_img) + qemu_img('create', '-f', iotests.imgfmt, '-o', 'backing_file=%s' % mid_img, test_img) + + qemu_io('-f', iotests.imgfmt, '-c', 'write -P 0x11 0 512k', mid_img) + qemu_io('-f', iotests.imgfmt, '-c', 'write -P 0x22 0 512k', test_img) + + self.vm = iotests.VM() + self.vm.launch() + + self.blkdebug_file = iotests.file_path("blkdebug.conf") + + def tearDown(self): + self.vm.shutdown() + os.remove(test_img) + os.remove(mid_img) + os.remove(backing_img) + + def blockdev_add(self, **kwargs): + result = self.vm.qmp('blockdev-add', **kwargs) + self.assert_qmp(result, 'return', {}) + + def add_block_nodes(self, base_debug=None, mid_debug=None, top_debug=None): + self.blockdev_add(node_name='base-file', driver='file', + filename=backing_img) + self.blockdev_add(node_name='mid-file', driver='file', + filename=mid_img) + self.blockdev_add(node_name='top-file', driver='file', + filename=test_img) + + if base_debug: + self.blockdev_add(node_name='base-dbg', driver='blkdebug', + image='base-file', inject_error=base_debug) + if mid_debug: + self.blockdev_add(node_name='mid-dbg', driver='blkdebug', + image='mid-file', inject_error=mid_debug) + if top_debug: + self.blockdev_add(node_name='top-dbg', driver='blkdebug', + image='top-file', inject_error=top_debug) + + self.blockdev_add(node_name='base-fmt', driver='raw', + file=('base-dbg' if base_debug else 'base-file')) + self.blockdev_add(node_name='mid-fmt', driver=iotests.imgfmt, + file=('mid-dbg' if mid_debug else 'mid-file'), + backing='base-fmt') + self.blockdev_add(node_name='top-fmt', driver=iotests.imgfmt, + file=('top-dbg' if top_debug else 'top-file'), + backing='mid-fmt') + + def run_job(self, expected_events, error_pauses_job=False): + match_device = {'data': {'device': 'job0'}} + events = [ + ('BLOCK_JOB_COMPLETED', match_device), + ('BLOCK_JOB_CANCELLED', match_device), + ('BLOCK_JOB_ERROR', match_device), + ('BLOCK_JOB_READY', match_device), + ] + + completed = False + log = [] + while not completed: + ev = self.vm.events_wait(events, timeout=5.0) + if ev['event'] == 'BLOCK_JOB_COMPLETED': + completed = True + elif ev['event'] == 'BLOCK_JOB_ERROR': + if error_pauses_job: + result = self.vm.qmp('block-job-resume', device='job0') + self.assert_qmp(result, 'return', {}) + elif ev['event'] == 'BLOCK_JOB_READY': + result = self.vm.qmp('block-job-complete', device='job0') + self.assert_qmp(result, 'return', {}) + else: + self.fail("Unexpected event: %s" % ev) + log.append(iotests.filter_qmp_event(ev)) + + self.maxDiff = None + self.assertEqual(expected_events, log) + + def event_error(self, op, action): + return { + 'event': 'BLOCK_JOB_ERROR', + 'data': {'action': action, 'device': 'job0', 'operation': op}, + 'timestamp': {'microseconds': 'USECS', 'seconds': 'SECS'} + } + + def event_ready(self): + return { + 'event': 'BLOCK_JOB_READY', + 'data': {'device': 'job0', + 'len': 524288, + 'offset': 524288, + 'speed': 0, + 'type': 'commit'}, + 'timestamp': {'microseconds': 'USECS', 'seconds': 'SECS'}, + } + + def event_completed(self, errmsg=None, active=True): + max_len = 524288 if active else self.image_len + data = { + 'device': 'job0', + 'len': max_len, + 'offset': 0 if errmsg else max_len, + 'speed': 0, + 'type': 'commit' + } + if errmsg: + data['error'] = errmsg + + return { + 'event': 'BLOCK_JOB_COMPLETED', + 'data': data, + 'timestamp': {'microseconds': 'USECS', 'seconds': 'SECS'}, + } + + def blkdebug_event(self, event, is_raw=False): + if event: + return [{ + 'event': event, + 'sector': 512 if is_raw else 1024, + 'once': True, + }] + return None + + def prepare_and_start_job(self, on_error, active=True, + top_event=None, mid_event=None, base_event=None): + + top_debug = self.blkdebug_event(top_event) + mid_debug = self.blkdebug_event(mid_event) + base_debug = self.blkdebug_event(base_event, True) + + self.add_block_nodes(top_debug=top_debug, mid_debug=mid_debug, + base_debug=base_debug) + + result = self.vm.qmp('block-commit', job_id='job0', device='top-fmt', + top_node='top-fmt' if active else 'mid-fmt', + base_node='mid-fmt' if active else 'base-fmt', + on_error=on_error) + self.assert_qmp(result, 'return', {}) + + def testActiveReadErrorReport(self): + self.prepare_and_start_job('report', top_event='read_aio') + self.run_job([ + self.event_error('read', 'report'), + self.event_completed('Input/output error') + ]) + + self.vm.shutdown() + self.assertFalse(iotests.compare_images(test_img, mid_img), + 'target image matches source after error') + + def testActiveReadErrorStop(self): + self.prepare_and_start_job('stop', top_event='read_aio') + self.run_job([ + self.event_error('read', 'stop'), + self.event_ready(), + self.event_completed() + ], error_pauses_job=True) + + self.vm.shutdown() + self.assertTrue(iotests.compare_images(test_img, mid_img), + 'target image does not match source after commit') + + def testActiveReadErrorIgnore(self): + self.prepare_and_start_job('ignore', top_event='read_aio') + self.run_job([ + self.event_error('read', 'ignore'), + self.event_ready(), + self.event_completed() + ]) + + # For commit, 'ignore' actually means retry, so this will succeed + self.vm.shutdown() + self.assertTrue(iotests.compare_images(test_img, mid_img), + 'target image does not match source after commit') + + def testActiveWriteErrorReport(self): + self.prepare_and_start_job('report', mid_event='write_aio') + self.run_job([ + self.event_error('write', 'report'), + self.event_completed('Input/output error') + ]) + + self.vm.shutdown() + self.assertFalse(iotests.compare_images(test_img, mid_img), + 'target image matches source after error') + + def testActiveWriteErrorStop(self): + self.prepare_and_start_job('stop', mid_event='write_aio') + self.run_job([ + self.event_error('write', 'stop'), + self.event_ready(), + self.event_completed() + ], error_pauses_job=True) + + self.vm.shutdown() + self.assertTrue(iotests.compare_images(test_img, mid_img), + 'target image does not match source after commit') + + def testActiveWriteErrorIgnore(self): + self.prepare_and_start_job('ignore', mid_event='write_aio') + self.run_job([ + self.event_error('write', 'ignore'), + self.event_ready(), + self.event_completed() + ]) + + # For commit, 'ignore' actually means retry, so this will succeed + self.vm.shutdown() + self.assertTrue(iotests.compare_images(test_img, mid_img), + 'target image does not match source after commit') + + def testIntermediateReadErrorReport(self): + self.prepare_and_start_job('report', active=False, mid_event='read_aio') + self.run_job([ + self.event_error('read', 'report'), + self.event_completed('Input/output error', active=False) + ]) + + self.vm.shutdown() + self.assertFalse(iotests.compare_images(mid_img, backing_img, fmt2='raw'), + 'target image matches source after error') + + def testIntermediateReadErrorStop(self): + self.prepare_and_start_job('stop', active=False, mid_event='read_aio') + self.run_job([ + self.event_error('read', 'stop'), + self.event_completed(active=False) + ], error_pauses_job=True) + + self.vm.shutdown() + self.assertTrue(iotests.compare_images(mid_img, backing_img, fmt2='raw'), + 'target image does not match source after commit') + + def testIntermediateReadErrorIgnore(self): + self.prepare_and_start_job('ignore', active=False, mid_event='read_aio') + self.run_job([ + self.event_error('read', 'ignore'), + self.event_completed(active=False) + ]) + + # For commit, 'ignore' actually means retry, so this will succeed + self.vm.shutdown() + self.assertTrue(iotests.compare_images(mid_img, backing_img, fmt2='raw'), + 'target image does not match source after commit') + + def testIntermediateWriteErrorReport(self): + self.prepare_and_start_job('report', active=False, base_event='write_aio') + self.run_job([ + self.event_error('write', 'report'), + self.event_completed('Input/output error', active=False) + ]) + + self.vm.shutdown() + self.assertFalse(iotests.compare_images(mid_img, backing_img, fmt2='raw'), + 'target image matches source after error') + + def testIntermediateWriteErrorStop(self): + self.prepare_and_start_job('stop', active=False, base_event='write_aio') + self.run_job([ + self.event_error('write', 'stop'), + self.event_completed(active=False) + ], error_pauses_job=True) + + self.vm.shutdown() + self.assertTrue(iotests.compare_images(mid_img, backing_img, fmt2='raw'), + 'target image does not match source after commit') + + def testIntermediateWriteErrorIgnore(self): + self.prepare_and_start_job('ignore', active=False, base_event='write_aio') + self.run_job([ + self.event_error('write', 'ignore'), + self.event_completed(active=False) + ]) + + # For commit, 'ignore' actually means retry, so this will succeed + self.vm.shutdown() + self.assertTrue(iotests.compare_images(mid_img, backing_img, fmt2='raw'), + 'target image does not match source after commit') + if __name__ == '__main__': iotests.main(supported_fmts=['qcow2', 'qed'], supported_protocols=['file']) diff --git a/tests/qemu-iotests/040.out b/tests/qemu-iotests/040.out index 220a5fa82c..6a917130b6 100644 --- a/tests/qemu-iotests/040.out +++ b/tests/qemu-iotests/040.out @@ -1,5 +1,5 @@ -............................................... +........................................................... ---------------------------------------------------------------------- -Ran 47 tests +Ran 59 tests OK diff --git a/tests/qemu-iotests/041 b/tests/qemu-iotests/041 index 43556b9727..5d67bf14bf 100755 --- a/tests/qemu-iotests/041 +++ b/tests/qemu-iotests/041 @@ -20,6 +20,7 @@ import time import os +import re import iotests from iotests import qemu_img, qemu_io @@ -34,6 +35,8 @@ quorum_img3 = os.path.join(iotests.test_dir, 'quorum3.img') quorum_repair_img = os.path.join(iotests.test_dir, 'quorum_repair.img') quorum_snapshot_file = os.path.join(iotests.test_dir, 'quorum_snapshot.img') +nbd_sock_path = os.path.join(iotests.test_dir, 'nbd.sock') + class TestSingleDrive(iotests.QMPTestCase): image_len = 1 * 1024 * 1024 # MB qmp_cmd = 'drive-mirror' @@ -80,7 +83,6 @@ class TestSingleDrive(iotests.QMPTestCase): self.cancel_and_wait(force=True) result = self.vm.qmp('query-block') self.assert_qmp(result, 'return[0]/inserted/file', test_img) - self.vm.shutdown() def test_cancel_after_ready(self): self.assert_no_active_block_jobs() @@ -201,8 +203,6 @@ class TestSingleDrive(iotests.QMPTestCase): self.assert_qmp(result, 'return[0]/node-name', 'top') self.assert_qmp(result, 'return[0]/backing/node-name', 'base') - self.vm.shutdown() - def test_medium_not_found(self): if iotests.qemu_default_machine != 'pc': return @@ -455,7 +455,6 @@ new_state = "1" self.assert_qmp(event, 'data/id', 'drive0') self.assert_no_active_block_jobs() - self.vm.shutdown() def test_ignore_read(self): self.assert_no_active_block_jobs() @@ -475,7 +474,6 @@ new_state = "1" result = self.vm.qmp('query-block-jobs') self.assert_qmp(result, 'return[0]/paused', False) self.complete_and_wait() - self.vm.shutdown() def test_large_cluster(self): self.assert_no_active_block_jobs() @@ -540,7 +538,6 @@ new_state = "1" self.complete_and_wait(wait_ready=False) self.assert_no_active_block_jobs() - self.vm.shutdown() class TestWriteErrors(iotests.QMPTestCase): image_len = 2 * 1024 * 1024 # MB @@ -614,7 +611,6 @@ new_state = "1" completed = True self.assert_no_active_block_jobs() - self.vm.shutdown() def test_ignore_write(self): self.assert_no_active_block_jobs() @@ -631,7 +627,6 @@ new_state = "1" result = self.vm.qmp('query-block-jobs') self.assert_qmp(result, 'return[0]/paused', False) self.complete_and_wait() - self.vm.shutdown() def test_stop_write(self): self.assert_no_active_block_jobs() @@ -667,7 +662,6 @@ new_state = "1" self.complete_and_wait(wait_ready=False) self.assert_no_active_block_jobs() - self.vm.shutdown() class TestSetSpeed(iotests.QMPTestCase): image_len = 80 * 1024 * 1024 # MB @@ -881,11 +875,14 @@ class TestRepairQuorum(iotests.QMPTestCase): # Add each individual quorum images for i in self.IMAGES: qemu_img('create', '-f', iotests.imgfmt, i, - str(TestSingleDrive.image_len)) + str(self.image_len)) # Assign a node name to each quorum image in order to manipulate # them opts = "node-name=img%i" % self.IMAGES.index(i) - self.vm = self.vm.add_drive(i, opts) + opts += ',driver=%s' % iotests.imgfmt + opts += ',file.driver=file' + opts += ',file.filename=%s' % i + self.vm = self.vm.add_blockdev(opts) self.vm.launch() @@ -898,7 +895,8 @@ class TestRepairQuorum(iotests.QMPTestCase): def tearDown(self): self.vm.shutdown() - for i in self.IMAGES + [ quorum_repair_img, quorum_snapshot_file ]: + for i in self.IMAGES + [ quorum_repair_img, quorum_snapshot_file, + nbd_sock_path ]: # Do a try/except because the test may have deleted some images try: os.remove(i) @@ -915,8 +913,7 @@ class TestRepairQuorum(iotests.QMPTestCase): self.complete_and_wait(drive="job0") self.assert_has_block_node("repair0", quorum_repair_img) - # TODO: a better test requiring some QEMU infrastructure will be added - # to check that this file is really driven by quorum + self.vm.assert_block_path('quorum0', '/children.1', 'repair0') self.vm.shutdown() self.assertTrue(iotests.compare_images(quorum_img2, quorum_repair_img), 'target image does not match source after mirroring') @@ -933,7 +930,6 @@ class TestRepairQuorum(iotests.QMPTestCase): # here we check that the last registered quorum file has not been # swapped out and unref self.assert_has_block_node(None, quorum_img3) - self.vm.shutdown() def test_cancel_after_ready(self): self.assert_no_active_block_jobs() @@ -1038,9 +1034,71 @@ class TestRepairQuorum(iotests.QMPTestCase): self.complete_and_wait('job0') self.assert_has_block_node("repair0", quorum_repair_img) - # TODO: a better test requiring some QEMU infrastructure will be added - # to check that this file is really driven by quorum + self.vm.assert_block_path('quorum0', '/children.1', 'repair0') + + def test_with_other_parent(self): + """ + Check that we cannot replace a Quorum child when it has other + parents. + """ + result = self.vm.qmp('nbd-server-start', + addr={ + 'type': 'unix', + 'data': {'path': nbd_sock_path} + }) + self.assert_qmp(result, 'return', {}) + + result = self.vm.qmp('nbd-server-add', device='img1') + self.assert_qmp(result, 'return', {}) + + result = self.vm.qmp('drive-mirror', job_id='mirror', device='quorum0', + sync='full', node_name='repair0', replaces='img1', + target=quorum_repair_img, format=iotests.imgfmt) + self.assert_qmp(result, 'error/desc', + "Cannot replace 'img1' by a node mirrored from " + "'quorum0', because it cannot be guaranteed that doing " + "so would not lead to an abrupt change of visible data") + + def test_with_other_parents_after_mirror_start(self): + """ + The same as test_with_other_parent(), but add the NBD server + only when the mirror job is already running. + """ + result = self.vm.qmp('nbd-server-start', + addr={ + 'type': 'unix', + 'data': {'path': nbd_sock_path} + }) + self.assert_qmp(result, 'return', {}) + + result = self.vm.qmp('drive-mirror', job_id='mirror', device='quorum0', + sync='full', node_name='repair0', replaces='img1', + target=quorum_repair_img, format=iotests.imgfmt) + self.assert_qmp(result, 'return', {}) + + result = self.vm.qmp('nbd-server-add', device='img1') + self.assert_qmp(result, 'return', {}) + + # The full error message goes to stderr, we will check it later + self.complete_and_wait('mirror', + completion_error='Operation not permitted') + + # Should not have been replaced + self.vm.assert_block_path('quorum0', '/children.1', 'img1') + + # Check the full error message now self.vm.shutdown() + log = self.vm.get_log() + log = re.sub(r'^\[I \d+\.\d+\] OPENED\n', '', log) + log = re.sub(r'^Formatting.*\n', '', log) + log = re.sub(r'\n\[I \+\d+\.\d+\] CLOSED\n?$', '', log) + log = re.sub(r'^%s: ' % os.path.basename(iotests.qemu_prog), '', log) + + self.assertEqual(log, + "Can no longer replace 'img1' by 'repair0', because " + + "it can no longer be guaranteed that doing so would " + + "not lead to an abrupt change of visible data") + # Test mirroring with a source that does not have any parents (not even a # BlockBackend) @@ -1132,6 +1190,52 @@ class TestOrphanedSource(iotests.QMPTestCase): self.assertFalse('mirror-filter' in nodes, 'Mirror filter node did not disappear') +# Test cases for @replaces that do not necessarily involve Quorum +class TestReplaces(iotests.QMPTestCase): + # Each of these test cases needs their own block graph, so do not + # create any nodes here + def setUp(self): + self.vm = iotests.VM() + self.vm.launch() + + def tearDown(self): + self.vm.shutdown() + for img in (test_img, target_img): + try: + os.remove(img) + except OSError: + pass + + @iotests.skip_if_unsupported(['copy-on-read']) + def test_replace_filter(self): + """ + Check that we can replace filter nodes. + """ + result = self.vm.qmp('blockdev-add', **{ + 'driver': 'copy-on-read', + 'node-name': 'filter0', + 'file': { + 'driver': 'copy-on-read', + 'node-name': 'filter1', + 'file': { + 'driver': 'null-co' + } + } + }) + self.assert_qmp(result, 'return', {}) + + result = self.vm.qmp('blockdev-add', + node_name='target', driver='null-co') + self.assert_qmp(result, 'return', {}) + + result = self.vm.qmp('blockdev-mirror', job_id='mirror', device='filter0', + target='target', sync='full', replaces='filter1') + self.assert_qmp(result, 'return', {}) + + self.complete_and_wait('mirror') + + self.vm.assert_block_path('filter0', '/file', 'target') + if __name__ == '__main__': iotests.main(supported_fmts=['qcow2', 'qed'], supported_protocols=['file'], diff --git a/tests/qemu-iotests/041.out b/tests/qemu-iotests/041.out index f496be9197..877b76fd31 100644 --- a/tests/qemu-iotests/041.out +++ b/tests/qemu-iotests/041.out @@ -1,5 +1,5 @@ -........................................................................................... +.............................................................................................. ---------------------------------------------------------------------- -Ran 91 tests +Ran 94 tests OK diff --git a/tests/qemu-iotests/155 b/tests/qemu-iotests/155 index e35b1d534b..f237868710 100755 --- a/tests/qemu-iotests/155 +++ b/tests/qemu-iotests/155 @@ -163,12 +163,7 @@ class MirrorBaseClass(BaseClass): self.assert_qmp(result, 'return', {}) - self.vm.event_wait('BLOCK_JOB_READY') - - result = self.vm.qmp('block-job-complete', device='mirror-job') - self.assert_qmp(result, 'return', {}) - - self.vm.event_wait('BLOCK_JOB_COMPLETED') + self.complete_and_wait('mirror-job') def testFull(self): self.runMirror('full') diff --git a/tests/qemu-iotests/244 b/tests/qemu-iotests/244 index 0d1efee6ef..2ec1815e6f 100755 --- a/tests/qemu-iotests/244 +++ b/tests/qemu-iotests/244 @@ -197,6 +197,20 @@ $QEMU_IO -c 'read -P 0x11 0 1M' -f $IMGFMT "$TEST_IMG" | _filter_qemu_io $QEMU_IMG map --output=human "$TEST_IMG" | _filter_testdir $QEMU_IMG map --output=json "$TEST_IMG" +echo +echo "=== Copy offloading ===" +echo + +# Make use of copy offloading if the test host can provide it +_make_test_img -o "data_file=$TEST_IMG.data" 64M +$QEMU_IMG convert -f $IMGFMT -O $IMGFMT -n -C "$TEST_IMG.src" "$TEST_IMG" +$QEMU_IMG compare -f $IMGFMT -F $IMGFMT "$TEST_IMG.src" "$TEST_IMG" + +# blkdebug doesn't support copy offloading, so this tests the error path +$QEMU_IMG amend -f $IMGFMT -o "data_file=blkdebug::$TEST_IMG.data" "$TEST_IMG" +$QEMU_IMG convert -f $IMGFMT -O $IMGFMT -n -C "$TEST_IMG.src" "$TEST_IMG" +$QEMU_IMG compare -f $IMGFMT -F $IMGFMT "$TEST_IMG.src" "$TEST_IMG" + # success, all done echo "*** done" rm -f $seq.full diff --git a/tests/qemu-iotests/244.out b/tests/qemu-iotests/244.out index 6a3d0067cc..e6f4dc7993 100644 --- a/tests/qemu-iotests/244.out +++ b/tests/qemu-iotests/244.out @@ -122,4 +122,10 @@ Offset Length Mapped to File 0 0x100000 0 TEST_DIR/t.qcow2.data [{ "start": 0, "length": 1048576, "depth": 0, "zero": false, "data": true, "offset": 0}, { "start": 1048576, "length": 66060288, "depth": 0, "zero": true, "data": false}] + +=== Copy offloading === + +Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 data_file=TEST_DIR/t.IMGFMT.data +Images are identical. +Images are identical. *** done diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py index 0473e824ed..8815052eb5 100644 --- a/tests/qemu-iotests/iotests.py +++ b/tests/qemu-iotests/iotests.py @@ -714,6 +714,65 @@ class VM(qtest.QEMUQtestMachine): return fields.items() <= ret.items() + def assert_block_path(self, root, path, expected_node, graph=None): + """ + Check whether the node under the given path in the block graph + is @expected_node. + + @root is the node name of the node where the @path is rooted. + + @path is a string that consists of child names separated by + slashes. It must begin with a slash. + + Examples for @root + @path: + - root="qcow2-node", path="/backing/file" + - root="quorum-node", path="/children.2/file" + + Hypothetically, @path could be empty, in which case it would + point to @root. However, in practice this case is not useful + and hence not allowed. + + @expected_node may be None. (All elements of the path but the + leaf must still exist.) + + @graph may be None or the result of an x-debug-query-block-graph + call that has already been performed. + """ + if graph is None: + graph = self.qmp('x-debug-query-block-graph')['return'] + + iter_path = iter(path.split('/')) + + # Must start with a / + assert next(iter_path) == '' + + node = next((node for node in graph['nodes'] if node['name'] == root), + None) + + # An empty @path is not allowed, so the root node must be present + assert node is not None, 'Root node %s not found' % root + + for child_name in iter_path: + assert node is not None, 'Cannot follow path %s%s' % (root, path) + + try: + node_id = next(edge['child'] for edge in graph['edges'] \ + if edge['parent'] == node['id'] and + edge['name'] == child_name) + + node = next(node for node in graph['nodes'] \ + if node['id'] == node_id) + except StopIteration: + node = None + + if node is None: + assert expected_node is None, \ + 'No node found under %s (but expected %s)' % \ + (path, expected_node) + else: + assert node['name'] == expected_node, \ + 'Found node %s under %s (but expected %s)' % \ + (node['name'], path, expected_node) index_re = re.compile(r'([^\[]+)\[([^\]]+)\]') |