1067
954
# prefix is the key in self._items to use, key_filter is the key_filter
1068
955
# entries that would match this node
1071
957
if key_filter is None:
1072
# yielding all nodes, yield whatever we have, and queue up a read
1073
# for whatever we are missing
1075
958
for prefix, node in self._items.iteritems():
1076
if node.__class__ is StaticTuple:
959
if type(node) == tuple:
1077
960
keys[node] = (prefix, None)
1079
962
yield node, None
1080
elif len(key_filter) == 1:
1081
# Technically, this path could also be handled by the first check
1082
# in 'self._node_width' in length_filters. However, we can handle
1083
# this case without spending any time building up the
1084
# prefix_to_keys, etc state.
1086
# This is a bit ugly, but TIMEIT showed it to be by far the fastest
1087
# 0.626us list(key_filter)[0]
1088
# is a func() for list(), 2 mallocs, and a getitem
1089
# 0.489us [k for k in key_filter][0]
1090
# still has the mallocs, avoids the func() call
1091
# 0.350us iter(key_filter).next()
1092
# has a func() call, and mallocs an iterator
1093
# 0.125us for key in key_filter: pass
1094
# no func() overhead, might malloc an iterator
1095
# 0.105us for key in key_filter: break
1096
# no func() overhead, might malloc an iterator, probably
1097
# avoids checking an 'else' clause as part of the for
1098
for key in key_filter:
1100
search_prefix = self._search_prefix_filter(key)
1101
if len(search_prefix) == self._node_width:
1102
# This item will match exactly, so just do a dict lookup, and
1103
# see what we can return
1106
node = self._items[search_prefix]
1108
# A given key can only match 1 child node, if it isn't
1109
# there, then we can just return nothing
1111
if node.__class__ is StaticTuple:
1112
keys[node] = (search_prefix, [key])
1114
# This is loaded, and the only thing that can match,
1119
# First, convert all keys into a list of search prefixes
1120
# Aggregate common prefixes, and track the keys they come from
1121
965
prefix_to_keys = {}
1122
966
length_filters = {}
1123
967
for key in key_filter:
1124
search_prefix = self._search_prefix_filter(key)
968
search_key = self._search_prefix_filter(key)
1125
969
length_filter = length_filters.setdefault(
1126
len(search_prefix), set())
1127
length_filter.add(search_prefix)
1128
prefix_to_keys.setdefault(search_prefix, []).append(key)
1130
if (self._node_width in length_filters
1131
and len(length_filters) == 1):
1132
# all of the search prefixes match exactly _node_width. This
1133
# means that everything is an exact match, and we can do a
1134
# lookup into self._items, rather than iterating over the items
1136
search_prefixes = length_filters[self._node_width]
1137
for search_prefix in search_prefixes:
1139
node = self._items[search_prefix]
1141
# We can ignore this one
1143
node_key_filter = prefix_to_keys[search_prefix]
1144
if node.__class__ is StaticTuple:
1145
keys[node] = (search_prefix, node_key_filter)
970
len(search_key), set())
971
length_filter.add(search_key)
972
prefix_to_keys.setdefault(search_key, []).append(key)
973
length_filters = length_filters.items()
974
for prefix, node in self._items.iteritems():
976
for length, length_filter in length_filters:
977
sub_prefix = prefix[:length]
978
if sub_prefix in length_filter:
979
node_key_filter.extend(prefix_to_keys[sub_prefix])
980
if node_key_filter: # this key matched something, yield it
981
if type(node) == tuple:
982
keys[node] = (prefix, node_key_filter)
1147
984
yield node, node_key_filter
1149
# The slow way. We walk every item in self._items, and check to
1150
# see if there are any matches
1151
length_filters = length_filters.items()
1152
for prefix, node in self._items.iteritems():
1153
node_key_filter = []
1154
for length, length_filter in length_filters:
1155
sub_prefix = prefix[:length]
1156
if sub_prefix in length_filter:
1157
node_key_filter.extend(prefix_to_keys[sub_prefix])
1158
if node_key_filter: # this key matched something, yield it
1159
if node.__class__ is StaticTuple:
1160
keys[node] = (prefix, node_key_filter)
1162
yield node, node_key_filter
1164
986
# Look in the page cache for some more bytes
1165
987
found_keys = set()
1166
988
for key in keys:
1168
bytes = _get_cache()[key]
990
bytes = _page_cache[key]
1169
991
except KeyError:
1466
class CHKMapDifference(object):
1467
"""Iterate the stored pages and key,value pairs for (new - old).
1469
This class provides a generator over the stored CHK pages and the
1470
(key, value) pairs that are in any of the new maps and not in any of the
1473
Note that it may yield chk pages that are common (especially root nodes),
1474
but it won't yield (key,value) pairs that are common.
1477
def __init__(self, store, new_root_keys, old_root_keys,
1478
search_key_func, pb=None):
1479
# TODO: Should we add a StaticTuple barrier here? It would be nice to
1480
# force callers to use StaticTuple, because there will often be
1481
# lots of keys passed in here. And even if we cast it locally,
1482
# that just meanst that we will have *both* a StaticTuple and a
1483
# tuple() in memory, referring to the same object. (so a net
1484
# increase in memory, not a decrease.)
1486
self._new_root_keys = new_root_keys
1487
self._old_root_keys = old_root_keys
1489
# All uninteresting chks that we have seen. By the time they are added
1490
# here, they should be either fully ignored, or queued up for
1492
# TODO: This might grow to a large size if there are lots of merge
1493
# parents, etc. However, it probably doesn't scale to O(history)
1494
# like _processed_new_refs does.
1495
self._all_old_chks = set(self._old_root_keys)
1496
# All items that we have seen from the old_root_keys
1497
self._all_old_items = set()
1498
# These are interesting items which were either read, or already in the
1499
# interesting queue (so we don't need to walk them again)
1500
# TODO: processed_new_refs becomes O(all_chks), consider switching to
1502
self._processed_new_refs = set()
1503
self._search_key_func = search_key_func
1505
# The uninteresting and interesting nodes to be searched
1506
self._old_queue = []
1507
self._new_queue = []
1508
# Holds the (key, value) items found when processing the root nodes,
1509
# waiting for the uninteresting nodes to be walked
1510
self._new_item_queue = []
1513
def _read_nodes_from_store(self, keys):
1514
# We chose not to use _get_cache(), because we think in
1515
# terms of records to be yielded. Also, we expect to touch each page
1516
# only 1 time during this code. (We may want to evaluate saving the
1517
# raw bytes into the page cache, which would allow a working tree
1518
# update after the fetch to not have to read the bytes again.)
1519
as_st = StaticTuple.from_sequence
1520
stream = self._store.get_record_stream(keys, 'unordered', True)
1521
for record in stream:
1522
if self._pb is not None:
1524
if record.storage_kind == 'absent':
1525
raise errors.NoSuchRevision(self._store, record.key)
1288
def _find_children_info(store, interesting_keys, uninteresting_keys, pb):
1289
"""Read the associated records, and determine what is interesting."""
1290
uninteresting_keys = set(uninteresting_keys)
1291
chks_to_read = uninteresting_keys.union(interesting_keys)
1292
next_uninteresting = set()
1293
next_interesting = set()
1294
uninteresting_items = set()
1295
interesting_items = set()
1296
interesting_to_yield = []
1297
for record in store.get_record_stream(chks_to_read, 'unordered', True):
1298
# records_read.add(record.key())
1301
bytes = record.get_bytes_as('fulltext')
1302
# We don't care about search_key_func for this code, because we only
1303
# care about external references.
1304
node = _deserialise(bytes, record.key, search_key_func=None)
1305
if record.key in uninteresting_keys:
1306
if type(node) is InternalNode:
1307
next_uninteresting.update(node.refs())
1309
# We know we are at a LeafNode, so we can pass None for the
1311
uninteresting_items.update(node.iteritems(None))
1313
interesting_to_yield.append(record.key)
1314
if type(node) is InternalNode:
1315
next_interesting.update(node.refs())
1317
interesting_items.update(node.iteritems(None))
1318
return (next_uninteresting, uninteresting_items,
1319
next_interesting, interesting_to_yield, interesting_items)
1322
def _find_all_uninteresting(store, interesting_root_keys,
1323
uninteresting_root_keys, pb):
1324
"""Determine the full set of uninteresting keys."""
1325
# What about duplicates between interesting_root_keys and
1326
# uninteresting_root_keys?
1327
if not uninteresting_root_keys:
1328
# Shortcut case. We know there is nothing uninteresting to filter out
1329
# So we just let the rest of the algorithm do the work
1330
# We know there is nothing uninteresting, and we didn't have to read
1331
# any interesting records yet.
1332
return (set(), set(), set(interesting_root_keys), [], set())
1333
all_uninteresting_chks = set(uninteresting_root_keys)
1334
all_uninteresting_items = set()
1336
# First step, find the direct children of both the interesting and
1338
(uninteresting_keys, uninteresting_items,
1339
interesting_keys, interesting_to_yield,
1340
interesting_items) = _find_children_info(store, interesting_root_keys,
1341
uninteresting_root_keys,
1343
all_uninteresting_chks.update(uninteresting_keys)
1344
all_uninteresting_items.update(uninteresting_items)
1345
del uninteresting_items
1346
# Note: Exact matches between interesting and uninteresting do not need
1347
# to be search further. Non-exact matches need to be searched in case
1348
# there is a future exact-match
1349
uninteresting_keys.difference_update(interesting_keys)
1351
# Second, find the full set of uninteresting bits reachable by the
1352
# uninteresting roots
1353
chks_to_read = uninteresting_keys
1356
for record in store.get_record_stream(chks_to_read, 'unordered', False):
1357
# TODO: Handle 'absent'
1526
1360
bytes = record.get_bytes_as('fulltext')
1527
node = _deserialise(bytes, record.key,
1528
search_key_func=self._search_key_func)
1361
# We don't care about search_key_func for this code, because we
1362
# only care about external references.
1363
node = _deserialise(bytes, record.key, search_key_func=None)
1529
1364
if type(node) is InternalNode:
1530
# Note we don't have to do node.refs() because we know that
1531
# there are no children that have been pushed into this node
1532
# Note: Using as_st() here seemed to save 1.2MB, which would
1533
# indicate that we keep 100k prefix_refs around while
1534
# processing. They *should* be shorter lived than that...
1535
# It does cost us ~10s of processing time
1536
#prefix_refs = [as_st(item) for item in node._items.iteritems()]
1537
prefix_refs = node._items.items()
1365
# uninteresting_prefix_chks.update(node._items.iteritems())
1366
chks = node._items.values()
1367
# TODO: We remove the entries that are already in
1368
# uninteresting_chks ?
1369
next_chks.update(chks)
1370
all_uninteresting_chks.update(chks)
1541
# Note: We don't use a StaticTuple here. Profiling showed a
1542
# minor memory improvement (0.8MB out of 335MB peak 0.2%)
1543
# But a significant slowdown (15s / 145s, or 10%)
1544
items = node._items.items()
1545
yield record, node, prefix_refs, items
1547
def _read_old_roots(self):
1548
old_chks_to_enqueue = []
1549
all_old_chks = self._all_old_chks
1550
for record, node, prefix_refs, items in \
1551
self._read_nodes_from_store(self._old_root_keys):
1552
# Uninteresting node
1553
prefix_refs = [p_r for p_r in prefix_refs
1554
if p_r[1] not in all_old_chks]
1555
new_refs = [p_r[1] for p_r in prefix_refs]
1556
all_old_chks.update(new_refs)
1557
# TODO: This might be a good time to turn items into StaticTuple
1558
# instances and possibly intern them. However, this does not
1559
# impact 'initial branch' performance, so I'm not worrying
1561
self._all_old_items.update(items)
1562
# Queue up the uninteresting references
1563
# Don't actually put them in the 'to-read' queue until we have
1564
# finished checking the interesting references
1565
old_chks_to_enqueue.extend(prefix_refs)
1566
return old_chks_to_enqueue
1568
def _enqueue_old(self, new_prefixes, old_chks_to_enqueue):
1569
# At this point, we have read all the uninteresting and interesting
1570
# items, so we can queue up the uninteresting stuff, knowing that we've
1571
# handled the interesting ones
1572
for prefix, ref in old_chks_to_enqueue:
1573
not_interesting = True
1574
for i in xrange(len(prefix), 0, -1):
1575
if prefix[:i] in new_prefixes:
1576
not_interesting = False
1579
# This prefix is not part of the remaining 'interesting set'
1581
self._old_queue.append(ref)
1583
def _read_all_roots(self):
1584
"""Read the root pages.
1586
This is structured as a generator, so that the root records can be
1587
yielded up to whoever needs them without any buffering.
1589
# This is the bootstrap phase
1590
if not self._old_root_keys:
1591
# With no old_root_keys we can just shortcut and be ready
1592
# for _flush_new_queue
1593
self._new_queue = list(self._new_root_keys)
1595
old_chks_to_enqueue = self._read_old_roots()
1596
# filter out any root keys that are already known to be uninteresting
1597
new_keys = set(self._new_root_keys).difference(self._all_old_chks)
1598
# These are prefixes that are present in new_keys that we are
1600
new_prefixes = set()
1601
# We are about to yield all of these, so we don't want them getting
1602
# added a second time
1603
processed_new_refs = self._processed_new_refs
1604
processed_new_refs.update(new_keys)
1605
for record, node, prefix_refs, items in \
1606
self._read_nodes_from_store(new_keys):
1607
# At this level, we now know all the uninteresting references
1608
# So we filter and queue up whatever is remaining
1609
prefix_refs = [p_r for p_r in prefix_refs
1610
if p_r[1] not in self._all_old_chks
1611
and p_r[1] not in processed_new_refs]
1612
refs = [p_r[1] for p_r in prefix_refs]
1613
new_prefixes.update([p_r[0] for p_r in prefix_refs])
1614
self._new_queue.extend(refs)
1615
# TODO: We can potentially get multiple items here, however the
1616
# current design allows for this, as callers will do the work
1617
# to make the results unique. We might profile whether we
1618
# gain anything by ensuring unique return values for items
1619
# TODO: This might be a good time to cast to StaticTuple, as
1620
# self._new_item_queue will hold the contents of multiple
1621
# records for an extended lifetime
1622
new_items = [item for item in items
1623
if item not in self._all_old_items]
1624
self._new_item_queue.extend(new_items)
1625
new_prefixes.update([self._search_key_func(item[0])
1626
for item in new_items])
1627
processed_new_refs.update(refs)
1629
# For new_prefixes we have the full length prefixes queued up.
1630
# However, we also need possible prefixes. (If we have a known ref to
1631
# 'ab', then we also need to include 'a'.) So expand the
1632
# new_prefixes to include all shorter prefixes
1633
for prefix in list(new_prefixes):
1634
new_prefixes.update([prefix[:i] for i in xrange(1, len(prefix))])
1635
self._enqueue_old(new_prefixes, old_chks_to_enqueue)
1637
def _flush_new_queue(self):
1638
# No need to maintain the heap invariant anymore, just pull things out
1640
refs = set(self._new_queue)
1641
self._new_queue = []
1642
# First pass, flush all interesting items and convert to using direct refs
1643
all_old_chks = self._all_old_chks
1644
processed_new_refs = self._processed_new_refs
1645
all_old_items = self._all_old_items
1646
new_items = [item for item in self._new_item_queue
1647
if item not in all_old_items]
1648
self._new_item_queue = []
1650
yield None, new_items
1651
refs = refs.difference(all_old_chks)
1652
processed_new_refs.update(refs)
1654
# TODO: Using a SimpleSet for self._processed_new_refs and
1655
# saved as much as 10MB of peak memory. However, it requires
1656
# implementing a non-pyrex version.
1658
next_refs_update = next_refs.update
1659
# Inlining _read_nodes_from_store improves 'bzr branch bzr.dev'
1660
# from 1m54s to 1m51s. Consider it.
1661
for record, _, p_refs, items in self._read_nodes_from_store(refs):
1663
# using the 'if' check saves about 145s => 141s, when
1664
# streaming initial branch of Launchpad data.
1665
items = [item for item in items
1666
if item not in all_old_items]
1668
next_refs_update([p_r[1] for p_r in p_refs])
1670
# set1.difference(set/dict) walks all of set1, and checks if it
1671
# exists in 'other'.
1672
# set1.difference(iterable) walks all of iterable, and does a
1673
# 'difference_update' on a clone of set1. Pick wisely based on the
1674
# expected sizes of objects.
1675
# in our case it is expected that 'new_refs' will always be quite
1677
next_refs = next_refs.difference(all_old_chks)
1678
next_refs = next_refs.difference(processed_new_refs)
1679
processed_new_refs.update(next_refs)
1682
def _process_next_old(self):
1683
# Since we don't filter uninteresting any further than during
1684
# _read_all_roots, process the whole queue in a single pass.
1685
refs = self._old_queue
1686
self._old_queue = []
1687
all_old_chks = self._all_old_chks
1688
for record, _, prefix_refs, items in self._read_nodes_from_store(refs):
1689
# TODO: Use StaticTuple here?
1690
self._all_old_items.update(items)
1691
refs = [r for _,r in prefix_refs if r not in all_old_chks]
1692
self._old_queue.extend(refs)
1693
all_old_chks.update(refs)
1695
def _process_queues(self):
1696
while self._old_queue:
1697
self._process_next_old()
1698
return self._flush_new_queue()
1701
for record in self._read_all_roots():
1703
for record, items in self._process_queues():
1372
all_uninteresting_items.update(node._items.iteritems())
1373
chks_to_read = next_chks
1374
return (all_uninteresting_chks, all_uninteresting_items,
1375
interesting_keys, interesting_to_yield, interesting_items)
1707
1378
def iter_interesting_nodes(store, interesting_root_keys,
1719
1390
(interesting record, {interesting key:values})
1721
iterator = CHKMapDifference(store, interesting_root_keys,
1722
uninteresting_root_keys,
1723
search_key_func=store._search_key_func,
1725
return iterator.process()
1392
# TODO: consider that it may be more memory efficient to use the 20-byte
1393
# sha1 string, rather than tuples of hexidecimal sha1 strings.
1394
# TODO: Try to factor out a lot of the get_record_stream() calls into a
1395
# helper function similar to _read_bytes. This function should be
1396
# able to use nodes from the _page_cache as well as actually
1397
# requesting bytes from the store.
1399
(all_uninteresting_chks, all_uninteresting_items, interesting_keys,
1400
interesting_to_yield, interesting_items) = _find_all_uninteresting(store,
1401
interesting_root_keys, uninteresting_root_keys, pb)
1403
# Now that we know everything uninteresting, we can yield information from
1405
interesting_items.difference_update(all_uninteresting_items)
1406
interesting_to_yield = set(interesting_to_yield) - all_uninteresting_chks
1407
if interesting_items:
1408
yield None, interesting_items
1409
if interesting_to_yield:
1410
# We request these records again, rather than buffering the root
1411
# records, most likely they are still in the _group_cache anyway.
1412
for record in store.get_record_stream(interesting_to_yield,
1413
'unordered', False):
1415
all_uninteresting_chks.update(interesting_to_yield)
1416
interesting_keys.difference_update(all_uninteresting_chks)
1418
chks_to_read = interesting_keys
1422
for record in store.get_record_stream(chks_to_read, 'unordered', False):
1425
pb.update('find chk pages', counter)
1426
# TODO: Handle 'absent'?
1427
bytes = record.get_bytes_as('fulltext')
1428
# We don't care about search_key_func for this code, because we
1429
# only care about external references.
1430
node = _deserialise(bytes, record.key, search_key_func=None)
1431
if type(node) is InternalNode:
1432
# all_uninteresting_chks grows large, as it lists all nodes we
1433
# don't want to process (including already seen interesting
1435
# small.difference_update(large) scales O(large), but
1436
# small.difference(large) scales O(small).
1437
# Also, we know we just _deserialised this node, so we can
1438
# access the dict directly.
1439
chks = set(node._items.itervalues()).difference(
1440
all_uninteresting_chks)
1441
# Is set() and .difference_update better than:
1442
# chks = [chk for chk in node.refs()
1443
# if chk not in all_uninteresting_chks]
1444
next_chks.update(chks)
1445
# These are now uninteresting everywhere else
1446
all_uninteresting_chks.update(chks)
1447
interesting_items = []
1449
interesting_items = [item for item in node._items.iteritems()
1450
if item not in all_uninteresting_items]
1451
# TODO: Do we need to filter out items that we have already
1452
# seen on other pages? We don't really want to buffer the
1453
# whole thing, but it does mean that callers need to
1454
# understand they may get duplicate values.
1455
# all_uninteresting_items.update(interesting_items)
1456
yield record, interesting_items
1457
chks_to_read = next_chks
added
removed
bzrlib/chk_map.py
