1064
954
# prefix is the key in self._items to use, key_filter is the key_filter
1065
955
# entries that would match this node
1068
957
if key_filter is None:
1069
# yielding all nodes, yield whatever we have, and queue up a read
1070
# for whatever we are missing
1072
958
for prefix, node in self._items.iteritems():
1073
if node.__class__ is StaticTuple:
959
if type(node) == tuple:
1074
960
keys[node] = (prefix, None)
1076
962
yield node, None
1077
elif len(key_filter) == 1:
1078
# Technically, this path could also be handled by the first check
1079
# in 'self._node_width' in length_filters. However, we can handle
1080
# this case without spending any time building up the
1081
# prefix_to_keys, etc state.
1083
# This is a bit ugly, but TIMEIT showed it to be by far the fastest
1084
# 0.626us list(key_filter)[0]
1085
# is a func() for list(), 2 mallocs, and a getitem
1086
# 0.489us [k for k in key_filter][0]
1087
# still has the mallocs, avoids the func() call
1088
# 0.350us iter(key_filter).next()
1089
# has a func() call, and mallocs an iterator
1090
# 0.125us for key in key_filter: pass
1091
# no func() overhead, might malloc an iterator
1092
# 0.105us for key in key_filter: break
1093
# no func() overhead, might malloc an iterator, probably
1094
# avoids checking an 'else' clause as part of the for
1095
for key in key_filter:
1097
search_prefix = self._search_prefix_filter(key)
1098
if len(search_prefix) == self._node_width:
1099
# This item will match exactly, so just do a dict lookup, and
1100
# see what we can return
1103
node = self._items[search_prefix]
1105
# A given key can only match 1 child node, if it isn't
1106
# there, then we can just return nothing
1108
if node.__class__ is StaticTuple:
1109
keys[node] = (search_prefix, [key])
1111
# This is loaded, and the only thing that can match,
1116
# First, convert all keys into a list of search prefixes
1117
# Aggregate common prefixes, and track the keys they come from
1118
965
prefix_to_keys = {}
1119
966
length_filters = {}
1120
967
for key in key_filter:
1121
search_prefix = self._search_prefix_filter(key)
968
search_key = self._search_prefix_filter(key)
1122
969
length_filter = length_filters.setdefault(
1123
len(search_prefix), set())
1124
length_filter.add(search_prefix)
1125
prefix_to_keys.setdefault(search_prefix, []).append(key)
1127
if (self._node_width in length_filters
1128
and len(length_filters) == 1):
1129
# all of the search prefixes match exactly _node_width. This
1130
# means that everything is an exact match, and we can do a
1131
# lookup into self._items, rather than iterating over the items
1133
search_prefixes = length_filters[self._node_width]
1134
for search_prefix in search_prefixes:
1136
node = self._items[search_prefix]
1138
# We can ignore this one
1140
node_key_filter = prefix_to_keys[search_prefix]
1141
if node.__class__ is StaticTuple:
1142
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)
1144
984
yield node, node_key_filter
1146
# The slow way. We walk every item in self._items, and check to
1147
# see if there are any matches
1148
length_filters = length_filters.items()
1149
for prefix, node in self._items.iteritems():
1150
node_key_filter = []
1151
for length, length_filter in length_filters:
1152
sub_prefix = prefix[:length]
1153
if sub_prefix in length_filter:
1154
node_key_filter.extend(prefix_to_keys[sub_prefix])
1155
if node_key_filter: # this key matched something, yield it
1156
if node.__class__ is StaticTuple:
1157
keys[node] = (prefix, node_key_filter)
1159
yield node, node_key_filter
1161
986
# Look in the page cache for some more bytes
1162
987
found_keys = set()
1163
988
for key in keys:
1165
bytes = _get_cache()[key]
990
bytes = _page_cache[key]
1166
991
except KeyError:
1463
class CHKMapDifference(object):
1464
"""Iterate the stored pages and key,value pairs for (new - old).
1466
This class provides a generator over the stored CHK pages and the
1467
(key, value) pairs that are in any of the new maps and not in any of the
1470
Note that it may yield chk pages that are common (especially root nodes),
1471
but it won't yield (key,value) pairs that are common.
1474
def __init__(self, store, new_root_keys, old_root_keys,
1475
search_key_func, pb=None):
1476
# TODO: Should we add a StaticTuple barrier here? It would be nice to
1477
# force callers to use StaticTuple, because there will often be
1478
# lots of keys passed in here. And even if we cast it locally,
1479
# that just meanst that we will have *both* a StaticTuple and a
1480
# tuple() in memory, referring to the same object. (so a net
1481
# increase in memory, not a decrease.)
1483
self._new_root_keys = new_root_keys
1484
self._old_root_keys = old_root_keys
1486
# All uninteresting chks that we have seen. By the time they are added
1487
# here, they should be either fully ignored, or queued up for
1489
# TODO: This might grow to a large size if there are lots of merge
1490
# parents, etc. However, it probably doesn't scale to O(history)
1491
# like _processed_new_refs does.
1492
self._all_old_chks = set(self._old_root_keys)
1493
# All items that we have seen from the old_root_keys
1494
self._all_old_items = set()
1495
# These are interesting items which were either read, or already in the
1496
# interesting queue (so we don't need to walk them again)
1497
# TODO: processed_new_refs becomes O(all_chks), consider switching to
1499
self._processed_new_refs = set()
1500
self._search_key_func = search_key_func
1502
# The uninteresting and interesting nodes to be searched
1503
self._old_queue = []
1504
self._new_queue = []
1505
# Holds the (key, value) items found when processing the root nodes,
1506
# waiting for the uninteresting nodes to be walked
1507
self._new_item_queue = []
1510
def _read_nodes_from_store(self, keys):
1511
# We chose not to use _get_cache(), because we think in
1512
# terms of records to be yielded. Also, we expect to touch each page
1513
# only 1 time during this code. (We may want to evaluate saving the
1514
# raw bytes into the page cache, which would allow a working tree
1515
# update after the fetch to not have to read the bytes again.)
1516
as_st = StaticTuple.from_sequence
1517
stream = self._store.get_record_stream(keys, 'unordered', True)
1518
for record in stream:
1519
if self._pb is not None:
1521
if record.storage_kind == 'absent':
1522
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'
1523
1360
bytes = record.get_bytes_as('fulltext')
1524
node = _deserialise(bytes, record.key,
1525
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)
1526
1364
if type(node) is InternalNode:
1527
# Note we don't have to do node.refs() because we know that
1528
# there are no children that have been pushed into this node
1529
# Note: Using as_st() here seemed to save 1.2MB, which would
1530
# indicate that we keep 100k prefix_refs around while
1531
# processing. They *should* be shorter lived than that...
1532
# It does cost us ~10s of processing time
1533
#prefix_refs = [as_st(item) for item in node._items.iteritems()]
1534
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)
1538
# Note: We don't use a StaticTuple here. Profiling showed a
1539
# minor memory improvement (0.8MB out of 335MB peak 0.2%)
1540
# But a significant slowdown (15s / 145s, or 10%)
1541
items = node._items.items()
1542
yield record, node, prefix_refs, items
1544
def _read_old_roots(self):
1545
old_chks_to_enqueue = []
1546
all_old_chks = self._all_old_chks
1547
for record, node, prefix_refs, items in \
1548
self._read_nodes_from_store(self._old_root_keys):
1549
# Uninteresting node
1550
prefix_refs = [p_r for p_r in prefix_refs
1551
if p_r[1] not in all_old_chks]
1552
new_refs = [p_r[1] for p_r in prefix_refs]
1553
all_old_chks.update(new_refs)
1554
# TODO: This might be a good time to turn items into StaticTuple
1555
# instances and possibly intern them. However, this does not
1556
# impact 'initial branch' performance, so I'm not worrying
1558
self._all_old_items.update(items)
1559
# Queue up the uninteresting references
1560
# Don't actually put them in the 'to-read' queue until we have
1561
# finished checking the interesting references
1562
old_chks_to_enqueue.extend(prefix_refs)
1563
return old_chks_to_enqueue
1565
def _enqueue_old(self, new_prefixes, old_chks_to_enqueue):
1566
# At this point, we have read all the uninteresting and interesting
1567
# items, so we can queue up the uninteresting stuff, knowing that we've
1568
# handled the interesting ones
1569
for prefix, ref in old_chks_to_enqueue:
1570
not_interesting = True
1571
for i in xrange(len(prefix), 0, -1):
1572
if prefix[:i] in new_prefixes:
1573
not_interesting = False
1576
# This prefix is not part of the remaining 'interesting set'
1578
self._old_queue.append(ref)
1580
def _read_all_roots(self):
1581
"""Read the root pages.
1583
This is structured as a generator, so that the root records can be
1584
yielded up to whoever needs them without any buffering.
1586
# This is the bootstrap phase
1587
if not self._old_root_keys:
1588
# With no old_root_keys we can just shortcut and be ready
1589
# for _flush_new_queue
1590
self._new_queue = list(self._new_root_keys)
1592
old_chks_to_enqueue = self._read_old_roots()
1593
# filter out any root keys that are already known to be uninteresting
1594
new_keys = set(self._new_root_keys).difference(self._all_old_chks)
1595
# These are prefixes that are present in new_keys that we are
1597
new_prefixes = set()
1598
# We are about to yield all of these, so we don't want them getting
1599
# added a second time
1600
processed_new_refs = self._processed_new_refs
1601
processed_new_refs.update(new_keys)
1602
for record, node, prefix_refs, items in \
1603
self._read_nodes_from_store(new_keys):
1604
# At this level, we now know all the uninteresting references
1605
# So we filter and queue up whatever is remaining
1606
prefix_refs = [p_r for p_r in prefix_refs
1607
if p_r[1] not in self._all_old_chks
1608
and p_r[1] not in processed_new_refs]
1609
refs = [p_r[1] for p_r in prefix_refs]
1610
new_prefixes.update([p_r[0] for p_r in prefix_refs])
1611
self._new_queue.extend(refs)
1612
# TODO: We can potentially get multiple items here, however the
1613
# current design allows for this, as callers will do the work
1614
# to make the results unique. We might profile whether we
1615
# gain anything by ensuring unique return values for items
1616
# TODO: This might be a good time to cast to StaticTuple, as
1617
# self._new_item_queue will hold the contents of multiple
1618
# records for an extended lifetime
1619
new_items = [item for item in items
1620
if item not in self._all_old_items]
1621
self._new_item_queue.extend(new_items)
1622
new_prefixes.update([self._search_key_func(item[0])
1623
for item in new_items])
1624
processed_new_refs.update(refs)
1626
# For new_prefixes we have the full length prefixes queued up.
1627
# However, we also need possible prefixes. (If we have a known ref to
1628
# 'ab', then we also need to include 'a'.) So expand the
1629
# new_prefixes to include all shorter prefixes
1630
for prefix in list(new_prefixes):
1631
new_prefixes.update([prefix[:i] for i in xrange(1, len(prefix))])
1632
self._enqueue_old(new_prefixes, old_chks_to_enqueue)
1634
def _flush_new_queue(self):
1635
# No need to maintain the heap invariant anymore, just pull things out
1637
refs = set(self._new_queue)
1638
self._new_queue = []
1639
# First pass, flush all interesting items and convert to using direct refs
1640
all_old_chks = self._all_old_chks
1641
processed_new_refs = self._processed_new_refs
1642
all_old_items = self._all_old_items
1643
new_items = [item for item in self._new_item_queue
1644
if item not in all_old_items]
1645
self._new_item_queue = []
1647
yield None, new_items
1648
refs = refs.difference(all_old_chks)
1649
processed_new_refs.update(refs)
1651
# TODO: Using a SimpleSet for self._processed_new_refs and
1652
# saved as much as 10MB of peak memory. However, it requires
1653
# implementing a non-pyrex version.
1655
next_refs_update = next_refs.update
1656
# Inlining _read_nodes_from_store improves 'bzr branch bzr.dev'
1657
# from 1m54s to 1m51s. Consider it.
1658
for record, _, p_refs, items in self._read_nodes_from_store(refs):
1660
# using the 'if' check saves about 145s => 141s, when
1661
# streaming initial branch of Launchpad data.
1662
items = [item for item in items
1663
if item not in all_old_items]
1665
next_refs_update([p_r[1] for p_r in p_refs])
1667
# set1.difference(set/dict) walks all of set1, and checks if it
1668
# exists in 'other'.
1669
# set1.difference(iterable) walks all of iterable, and does a
1670
# 'difference_update' on a clone of set1. Pick wisely based on the
1671
# expected sizes of objects.
1672
# in our case it is expected that 'new_refs' will always be quite
1674
next_refs = next_refs.difference(all_old_chks)
1675
next_refs = next_refs.difference(processed_new_refs)
1676
processed_new_refs.update(next_refs)
1679
def _process_next_old(self):
1680
# Since we don't filter uninteresting any further than during
1681
# _read_all_roots, process the whole queue in a single pass.
1682
refs = self._old_queue
1683
self._old_queue = []
1684
all_old_chks = self._all_old_chks
1685
for record, _, prefix_refs, items in self._read_nodes_from_store(refs):
1686
# TODO: Use StaticTuple here?
1687
self._all_old_items.update(items)
1688
refs = [r for _,r in prefix_refs if r not in all_old_chks]
1689
self._old_queue.extend(refs)
1690
all_old_chks.update(refs)
1692
def _process_queues(self):
1693
while self._old_queue:
1694
self._process_next_old()
1695
return self._flush_new_queue()
1698
for record in self._read_all_roots():
1700
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)
1704
1378
def iter_interesting_nodes(store, interesting_root_keys,
1716
1390
(interesting record, {interesting key:values})
1718
iterator = CHKMapDifference(store, interesting_root_keys,
1719
uninteresting_root_keys,
1720
search_key_func=store._search_key_func,
1722
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
1726
1461
from bzrlib._chk_map_pyx import (
1728
1462
_search_key_16,
1729
1463
_search_key_255,
1730
1464
_deserialise_leaf_node,
1731
1465
_deserialise_internal_node,
1733
except ImportError, e:
1734
osutils.failed_to_load_extension(e)
1735
1468
from bzrlib._chk_map_py import (
1737
1469
_search_key_16,
1738
1470
_search_key_255,
1739
1471
_deserialise_leaf_node,
added
removed
bzrlib/chk_map.py
