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# Copyright (C) 2007-2010 Canonical Ltd
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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"""Indexing facilities."""
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'GraphIndexPrefixAdapter',
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from bisect import bisect_right
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from cStringIO import StringIO
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from bzrlib.lazy_import import lazy_import
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lazy_import(globals(), """
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from bzrlib import trace
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from bzrlib.bisect_multi import bisect_multi_bytes
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from bzrlib.revision import NULL_REVISION
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from bzrlib.trace import mutter
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from bzrlib.static_tuple import StaticTuple
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_HEADER_READV = (0, 200)
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_OPTION_KEY_ELEMENTS = "key_elements="
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_OPTION_NODE_REFS = "node_ref_lists="
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_SIGNATURE = "Bazaar Graph Index 1\n"
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_whitespace_re = re.compile('[\t\n\x0b\x0c\r\x00 ]')
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_newline_null_re = re.compile('[\n\0]')
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def _has_key_from_parent_map(self, key):
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"""Check if this index has one key.
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If it's possible to check for multiple keys at once through
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calling get_parent_map that should be faster.
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return (key in self.get_parent_map([key]))
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def _missing_keys_from_parent_map(self, keys):
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return set(keys) - set(self.get_parent_map(keys))
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class GraphIndexBuilder(object):
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"""A builder that can build a GraphIndex.
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The resulting graph has the structure:
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_SIGNATURE OPTIONS NODES NEWLINE
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_SIGNATURE := 'Bazaar Graph Index 1' NEWLINE
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OPTIONS := 'node_ref_lists=' DIGITS NEWLINE
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NODE := KEY NULL ABSENT? NULL REFERENCES NULL VALUE NEWLINE
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KEY := Not-whitespace-utf8
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REFERENCES := REFERENCE_LIST (TAB REFERENCE_LIST){node_ref_lists - 1}
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REFERENCE_LIST := (REFERENCE (CR REFERENCE)*)?
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REFERENCE := DIGITS ; digits is the byte offset in the index of the
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VALUE := no-newline-no-null-bytes
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def __init__(self, reference_lists=0, key_elements=1):
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"""Create a GraphIndex builder.
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:param reference_lists: The number of node references lists for each
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:param key_elements: The number of bytestrings in each key.
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self.reference_lists = reference_lists
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# A dict of {key: (absent, ref_lists, value)}
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# Keys that are referenced but not actually present in this index
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self._absent_keys = set()
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self._nodes_by_key = None
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self._key_length = key_elements
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self._optimize_for_size = False
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self._combine_backing_indices = True
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def _check_key(self, key):
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"""Raise BadIndexKey if key is not a valid key for this index."""
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if type(key) not in (tuple, StaticTuple):
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raise errors.BadIndexKey(key)
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if self._key_length != len(key):
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raise errors.BadIndexKey(key)
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if not element or _whitespace_re.search(element) is not None:
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raise errors.BadIndexKey(element)
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def _external_references(self):
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"""Return references that are not present in this index.
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# TODO: JAM 2008-11-21 This makes an assumption about how the reference
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# lists are used. It is currently correct for pack-0.92 through
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# 1.9, which use the node references (3rd column) second
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# reference list as the compression parent. Perhaps this should
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# be moved into something higher up the stack, since it
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# makes assumptions about how the index is used.
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if self.reference_lists > 1:
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for node in self.iter_all_entries():
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refs.update(node[3][1])
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# If reference_lists == 0 there can be no external references, and
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# if reference_lists == 1, then there isn't a place to store the
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def _get_nodes_by_key(self):
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if self._nodes_by_key is None:
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if self.reference_lists:
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for key, (absent, references, value) in self._nodes.iteritems():
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key_dict = nodes_by_key
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for subkey in key[:-1]:
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key_dict = key_dict.setdefault(subkey, {})
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key_dict[key[-1]] = key, value, references
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for key, (absent, references, value) in self._nodes.iteritems():
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key_dict = nodes_by_key
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for subkey in key[:-1]:
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key_dict = key_dict.setdefault(subkey, {})
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key_dict[key[-1]] = key, value
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self._nodes_by_key = nodes_by_key
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return self._nodes_by_key
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def _update_nodes_by_key(self, key, value, node_refs):
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"""Update the _nodes_by_key dict with a new key.
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For a key of (foo, bar, baz) create
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_nodes_by_key[foo][bar][baz] = key_value
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if self._nodes_by_key is None:
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key_dict = self._nodes_by_key
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if self.reference_lists:
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key_value = StaticTuple(key, value, node_refs)
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key_value = StaticTuple(key, value)
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for subkey in key[:-1]:
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key_dict = key_dict.setdefault(subkey, {})
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key_dict[key[-1]] = key_value
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def _check_key_ref_value(self, key, references, value):
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"""Check that 'key' and 'references' are all valid.
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:param key: A key tuple. Must conform to the key interface (be a tuple,
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be of the right length, not have any whitespace or nulls in any key
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:param references: An iterable of reference lists. Something like
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[[(ref, key)], [(ref, key), (other, key)]]
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:param value: The value associate with this key. Must not contain
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newlines or null characters.
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:return: (node_refs, absent_references)
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node_refs basically a packed form of 'references' where all
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absent_references reference keys that are not in self._nodes.
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This may contain duplicates if the same key is
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referenced in multiple lists.
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as_st = StaticTuple.from_sequence
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if _newline_null_re.search(value) is not None:
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raise errors.BadIndexValue(value)
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if len(references) != self.reference_lists:
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raise errors.BadIndexValue(references)
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absent_references = []
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for reference_list in references:
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for reference in reference_list:
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# If reference *is* in self._nodes, then we know it has already
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if reference not in self._nodes:
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self._check_key(reference)
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absent_references.append(reference)
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reference_list = as_st([as_st(ref).intern()
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for ref in reference_list])
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node_refs.append(reference_list)
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return as_st(node_refs), absent_references
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def add_node(self, key, value, references=()):
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"""Add a node to the index.
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:param key: The key. keys are non-empty tuples containing
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as many whitespace-free utf8 bytestrings as the key length
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defined for this index.
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:param references: An iterable of iterables of keys. Each is a
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reference to another key.
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:param value: The value to associate with the key. It may be any
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bytes as long as it does not contain \0 or \n.
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absent_references) = self._check_key_ref_value(key, references, value)
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if key in self._nodes and self._nodes[key][0] != 'a':
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raise errors.BadIndexDuplicateKey(key, self)
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for reference in absent_references:
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# There may be duplicates, but I don't think it is worth worrying
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self._nodes[reference] = ('a', (), '')
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self._absent_keys.update(absent_references)
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self._absent_keys.discard(key)
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self._nodes[key] = ('', node_refs, value)
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if self._nodes_by_key is not None and self._key_length > 1:
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self._update_nodes_by_key(key, value, node_refs)
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def clear_cache(self):
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"""See GraphIndex.clear_cache()
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This is a no-op, but we need the api to conform to a generic 'Index'
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lines.append(_OPTION_NODE_REFS + str(self.reference_lists) + '\n')
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lines.append(_OPTION_KEY_ELEMENTS + str(self._key_length) + '\n')
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key_count = len(self._nodes) - len(self._absent_keys)
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lines.append(_OPTION_LEN + str(key_count) + '\n')
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prefix_length = sum(len(x) for x in lines)
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# references are byte offsets. To avoid having to do nasty
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# polynomial work to resolve offsets (references to later in the
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# file cannot be determined until all the inbetween references have
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# been calculated too) we pad the offsets with 0's to make them be
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# of consistent length. Using binary offsets would break the trivial
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# to calculate the width of zero's needed we do three passes:
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# one to gather all the non-reference data and the number of references.
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# one to pad all the data with reference-length and determine entry
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# forward sorted by key. In future we may consider topological sorting,
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# at the cost of table scans for direct lookup, or a second index for
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nodes = sorted(self._nodes.items())
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# if we do not prepass, we don't know how long it will be up front.
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expected_bytes = None
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# we only need to pre-pass if we have reference lists at all.
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if self.reference_lists:
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non_ref_bytes = prefix_length
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# TODO use simple multiplication for the constants in this loop.
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for key, (absent, references, value) in nodes:
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# record the offset known *so far* for this key:
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# the non reference bytes to date, and the total references to
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# date - saves reaccumulating on the second pass
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key_offset_info.append((key, non_ref_bytes, total_references))
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# key is literal, value is literal, there are 3 null's, 1 NL
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# key is variable length tuple, \x00 between elements
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non_ref_bytes += sum(len(element) for element in key)
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if self._key_length > 1:
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non_ref_bytes += self._key_length - 1
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# value is literal bytes, there are 3 null's, 1 NL.
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non_ref_bytes += len(value) + 3 + 1
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# one byte for absent if set.
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elif self.reference_lists:
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# (ref_lists -1) tabs
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non_ref_bytes += self.reference_lists - 1
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# (ref-1 cr's per ref_list)
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for ref_list in references:
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# how many references across the whole file?
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total_references += len(ref_list)
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# accrue reference separators
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non_ref_bytes += len(ref_list) - 1
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# how many digits are needed to represent the total byte count?
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possible_total_bytes = non_ref_bytes + total_references*digits
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while 10 ** digits < possible_total_bytes:
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possible_total_bytes = non_ref_bytes + total_references*digits
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expected_bytes = possible_total_bytes + 1 # terminating newline
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# resolve key addresses.
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for key, non_ref_bytes, total_references in key_offset_info:
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key_addresses[key] = non_ref_bytes + total_references*digits
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format_string = '%%0%sd' % digits
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for key, (absent, references, value) in nodes:
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flattened_references = []
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for ref_list in references:
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for reference in ref_list:
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ref_addresses.append(format_string % key_addresses[reference])
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flattened_references.append('\r'.join(ref_addresses))
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string_key = '\x00'.join(key)
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lines.append("%s\x00%s\x00%s\x00%s\n" % (string_key, absent,
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'\t'.join(flattened_references), value))
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result = StringIO(''.join(lines))
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if expected_bytes and len(result.getvalue()) != expected_bytes:
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raise errors.BzrError('Failed index creation. Internal error:'
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' mismatched output length and expected length: %d %d' %
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(len(result.getvalue()), expected_bytes))
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def set_optimize(self, for_size=None, combine_backing_indices=None):
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"""Change how the builder tries to optimize the result.
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:param for_size: Tell the builder to try and make the index as small as
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:param combine_backing_indices: If the builder spills to disk to save
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memory, should the on-disk indices be combined. Set to True if you
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are going to be probing the index, but to False if you are not. (If
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you are not querying, then the time spent combining is wasted.)
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# GraphIndexBuilder itself doesn't pay attention to the flag yet, but
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if for_size is not None:
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self._optimize_for_size = for_size
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if combine_backing_indices is not None:
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self._combine_backing_indices = combine_backing_indices
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def find_ancestry(self, keys, ref_list_num):
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"""See CombinedGraphIndex.find_ancestry()"""
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for _, key, value, ref_lists in self.iter_entries(pending):
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parent_keys = ref_lists[ref_list_num]
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parent_map[key] = parent_keys
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next_pending.update([p for p in parent_keys if p not in
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missing_keys.update(pending.difference(parent_map))
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pending = next_pending
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return parent_map, missing_keys
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class GraphIndex(object):
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"""An index for data with embedded graphs.
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The index maps keys to a list of key reference lists, and a value.
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Each node has the same number of key reference lists. Each key reference
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list can be empty or an arbitrary length. The value is an opaque NULL
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terminated string without any newlines. The storage of the index is
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hidden in the interface: keys and key references are always tuples of
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bytestrings, never the internal representation (e.g. dictionary offsets).
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It is presumed that the index will not be mutated - it is static data.
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Successive iter_all_entries calls will read the entire index each time.
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Additionally, iter_entries calls will read the index linearly until the
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desired keys are found. XXX: This must be fixed before the index is
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suitable for production use. :XXX
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def __init__(self, transport, name, size, unlimited_cache=False, offset=0):
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"""Open an index called name on transport.
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:param transport: A bzrlib.transport.Transport.
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:param name: A path to provide to transport API calls.
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:param size: The size of the index in bytes. This is used for bisection
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logic to perform partial index reads. While the size could be
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obtained by statting the file this introduced an additional round
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trip as well as requiring stat'able transports, both of which are
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avoided by having it supplied. If size is None, then bisection
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support will be disabled and accessing the index will just stream
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:param offset: Instead of starting the index data at offset 0, start it
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at an arbitrary offset.
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self._transport = transport
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# Becomes a dict of key:(value, reference-list-byte-locations) used by
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# the bisection interface to store parsed but not resolved keys.
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self._bisect_nodes = None
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# Becomes a dict of key:(value, reference-list-keys) which are ready to
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# be returned directly to callers.
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# a sorted list of slice-addresses for the parsed bytes of the file.
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# e.g. (0,1) would mean that byte 0 is parsed.
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self._parsed_byte_map = []
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# a sorted list of keys matching each slice address for parsed bytes
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# e.g. (None, 'foo@bar') would mean that the first byte contained no
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# key, and the end byte of the slice is the of the data for 'foo@bar'
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self._parsed_key_map = []
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self._key_count = None
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self._keys_by_offset = None
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self._nodes_by_key = None
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# The number of bytes we've read so far in trying to process this file
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self._base_offset = offset
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def __eq__(self, other):
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"""Equal when self and other were created with the same parameters."""
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type(self) == type(other) and
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self._transport == other._transport and
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self._name == other._name and
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self._size == other._size)
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def __ne__(self, other):
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return not self.__eq__(other)
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return "%s(%r)" % (self.__class__.__name__,
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self._transport.abspath(self._name))
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def _buffer_all(self, stream=None):
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"""Buffer all the index data.
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Mutates self._nodes and self.keys_by_offset.
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if self._nodes is not None:
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# We already did this
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if 'index' in debug.debug_flags:
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mutter('Reading entire index %s', self._transport.abspath(self._name))
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stream = self._transport.get(self._name)
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if self._base_offset != 0:
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# This is wasteful, but it is better than dealing with
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# adjusting all the offsets, etc.
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stream = StringIO(stream.read()[self._base_offset:])
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self._read_prefix(stream)
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self._expected_elements = 3 + self._key_length
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# raw data keyed by offset
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self._keys_by_offset = {}
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# ready-to-return key:value or key:value, node_ref_lists
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self._nodes_by_key = None
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lines = stream.read().split('\n')
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_, _, _, trailers = self._parse_lines(lines, pos)
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for key, absent, references, value in self._keys_by_offset.itervalues():
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# resolve references:
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if self.node_ref_lists:
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node_value = (value, self._resolve_references(references))
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self._nodes[key] = node_value
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# cache the keys for quick set intersections
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# there must be one line - the empty trailer line.
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raise errors.BadIndexData(self)
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def clear_cache(self):
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"""Clear out any cached/memoized values.
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This can be called at any time, but generally it is used when we have
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extracted some information, but don't expect to be requesting any more
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def external_references(self, ref_list_num):
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"""Return references that are not present in this index.
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if ref_list_num + 1 > self.node_ref_lists:
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raise ValueError('No ref list %d, index has %d ref lists'
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% (ref_list_num, self.node_ref_lists))
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for key, (value, ref_lists) in nodes.iteritems():
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ref_list = ref_lists[ref_list_num]
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refs.update([ref for ref in ref_list if ref not in nodes])
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def _get_nodes_by_key(self):
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if self._nodes_by_key is None:
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if self.node_ref_lists:
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for key, (value, references) in self._nodes.iteritems():
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key_dict = nodes_by_key
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for subkey in key[:-1]:
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key_dict = key_dict.setdefault(subkey, {})
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key_dict[key[-1]] = key, value, references
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for key, value in self._nodes.iteritems():
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key_dict = nodes_by_key
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for subkey in key[:-1]:
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key_dict = key_dict.setdefault(subkey, {})
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key_dict[key[-1]] = key, value
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self._nodes_by_key = nodes_by_key
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return self._nodes_by_key
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def iter_all_entries(self):
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"""Iterate over all keys within the index.
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:return: An iterable of (index, key, value) or (index, key, value, reference_lists).
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The former tuple is used when there are no reference lists in the
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index, making the API compatible with simple key:value index types.
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There is no defined order for the result iteration - it will be in
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the most efficient order for the index.
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if 'evil' in debug.debug_flags:
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trace.mutter_callsite(3,
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"iter_all_entries scales with size of history.")
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if self._nodes is None:
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if self.node_ref_lists:
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for key, (value, node_ref_lists) in self._nodes.iteritems():
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yield self, key, value, node_ref_lists
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for key, value in self._nodes.iteritems():
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yield self, key, value
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def _read_prefix(self, stream):
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signature = stream.read(len(self._signature()))
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if not signature == self._signature():
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raise errors.BadIndexFormatSignature(self._name, GraphIndex)
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options_line = stream.readline()
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if not options_line.startswith(_OPTION_NODE_REFS):
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raise errors.BadIndexOptions(self)
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self.node_ref_lists = int(options_line[len(_OPTION_NODE_REFS):-1])
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raise errors.BadIndexOptions(self)
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options_line = stream.readline()
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if not options_line.startswith(_OPTION_KEY_ELEMENTS):
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raise errors.BadIndexOptions(self)
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self._key_length = int(options_line[len(_OPTION_KEY_ELEMENTS):-1])
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raise errors.BadIndexOptions(self)
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options_line = stream.readline()
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if not options_line.startswith(_OPTION_LEN):
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raise errors.BadIndexOptions(self)
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self._key_count = int(options_line[len(_OPTION_LEN):-1])
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raise errors.BadIndexOptions(self)
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def _resolve_references(self, references):
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"""Return the resolved key references for references.
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References are resolved by looking up the location of the key in the
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_keys_by_offset map and substituting the key name, preserving ordering.
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:param references: An iterable of iterables of key locations. e.g.
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:return: A tuple of tuples of keys.
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for ref_list in references:
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node_refs.append(tuple([self._keys_by_offset[ref][0] for ref in ref_list]))
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return tuple(node_refs)
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def _find_index(self, range_map, key):
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"""Helper for the _parsed_*_index calls.
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Given a range map - [(start, end), ...], finds the index of the range
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in the map for key if it is in the map, and if it is not there, the
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immediately preceeding range in the map.
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result = bisect_right(range_map, key) - 1
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if result + 1 < len(range_map):
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# check the border condition, it may be in result + 1
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if range_map[result + 1][0] == key[0]:
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def _parsed_byte_index(self, offset):
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"""Return the index of the entry immediately before offset.
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e.g. if the parsed map has regions 0,10 and 11,12 parsed, meaning that
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there is one unparsed byte (the 11th, addressed as[10]). then:
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asking for 0 will return 0
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asking for 10 will return 0
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asking for 11 will return 1
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asking for 12 will return 1
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return self._find_index(self._parsed_byte_map, key)
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def _parsed_key_index(self, key):
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"""Return the index of the entry immediately before key.
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e.g. if the parsed map has regions (None, 'a') and ('b','c') parsed,
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meaning that keys from None to 'a' inclusive, and 'b' to 'c' inclusive
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have been parsed, then:
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asking for '' will return 0
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asking for 'a' will return 0
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asking for 'b' will return 1
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asking for 'e' will return 1
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search_key = (key, None)
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return self._find_index(self._parsed_key_map, search_key)
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def _is_parsed(self, offset):
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"""Returns True if offset has been parsed."""
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index = self._parsed_byte_index(offset)
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if index == len(self._parsed_byte_map):
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return offset < self._parsed_byte_map[index - 1][1]
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start, end = self._parsed_byte_map[index]
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return offset >= start and offset < end
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def _iter_entries_from_total_buffer(self, keys):
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"""Iterate over keys when the entire index is parsed."""
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# Note: See the note in BTreeBuilder.iter_entries for why we don't use
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# .intersection() here
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keys = [key for key in keys if key in nodes]
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if self.node_ref_lists:
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value, node_refs = nodes[key]
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yield self, key, value, node_refs
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yield self, key, nodes[key]
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def iter_entries(self, keys):
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"""Iterate over keys within the index.
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:param keys: An iterable providing the keys to be retrieved.
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:return: An iterable as per iter_all_entries, but restricted to the
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keys supplied. No additional keys will be returned, and every
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key supplied that is in the index will be returned.
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if self._size is None and self._nodes is None:
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# We fit about 20 keys per minimum-read (4K), so if we are looking for
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# more than 1/20th of the index its likely (assuming homogenous key
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# spread) that we'll read the entire index. If we're going to do that,
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# buffer the whole thing. A better analysis might take key spread into
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# account - but B+Tree indices are better anyway.
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# We could look at all data read, and use a threshold there, which will
667
# trigger on ancestry walks, but that is not yet fully mapped out.
668
if self._nodes is None and len(keys) * 20 > self.key_count():
670
if self._nodes is not None:
671
return self._iter_entries_from_total_buffer(keys)
673
return (result[1] for result in bisect_multi_bytes(
674
self._lookup_keys_via_location, self._size, keys))
676
def iter_entries_prefix(self, keys):
677
"""Iterate over keys within the index using prefix matching.
679
Prefix matching is applied within the tuple of a key, not to within
680
the bytestring of each key element. e.g. if you have the keys ('foo',
681
'bar'), ('foobar', 'gam') and do a prefix search for ('foo', None) then
682
only the former key is returned.
684
WARNING: Note that this method currently causes a full index parse
685
unconditionally (which is reasonably appropriate as it is a means for
686
thunking many small indices into one larger one and still supplies
687
iter_all_entries at the thunk layer).
689
:param keys: An iterable providing the key prefixes to be retrieved.
690
Each key prefix takes the form of a tuple the length of a key, but
691
with the last N elements 'None' rather than a regular bytestring.
692
The first element cannot be 'None'.
693
:return: An iterable as per iter_all_entries, but restricted to the
694
keys with a matching prefix to those supplied. No additional keys
695
will be returned, and every match that is in the index will be
701
# load data - also finds key lengths
702
if self._nodes is None:
704
if self._key_length == 1:
708
raise errors.BadIndexKey(key)
709
if len(key) != self._key_length:
710
raise errors.BadIndexKey(key)
711
if self.node_ref_lists:
712
value, node_refs = self._nodes[key]
713
yield self, key, value, node_refs
715
yield self, key, self._nodes[key]
717
nodes_by_key = self._get_nodes_by_key()
721
raise errors.BadIndexKey(key)
722
if len(key) != self._key_length:
723
raise errors.BadIndexKey(key)
724
# find what it refers to:
725
key_dict = nodes_by_key
727
# find the subdict whose contents should be returned.
729
while len(elements) and elements[0] is not None:
730
key_dict = key_dict[elements[0]]
733
# a non-existant lookup.
738
key_dict = dicts.pop(-1)
739
# can't be empty or would not exist
740
item, value = key_dict.iteritems().next()
741
if type(value) == dict:
743
dicts.extend(key_dict.itervalues())
746
for value in key_dict.itervalues():
747
# each value is the key:value:node refs tuple
749
yield (self, ) + value
751
# the last thing looked up was a terminal element
752
yield (self, ) + key_dict
754
def _find_ancestors(self, keys, ref_list_num, parent_map, missing_keys):
755
"""See BTreeIndex._find_ancestors."""
756
# The api can be implemented as a trivial overlay on top of
757
# iter_entries, it is not an efficient implementation, but it at least
761
for index, key, value, refs in self.iter_entries(keys):
762
parent_keys = refs[ref_list_num]
764
parent_map[key] = parent_keys
765
search_keys.update(parent_keys)
766
# Figure out what, if anything, was missing
767
missing_keys.update(set(keys).difference(found_keys))
768
search_keys = search_keys.difference(parent_map)
772
"""Return an estimate of the number of keys in this index.
774
For GraphIndex the estimate is exact.
776
if self._key_count is None:
777
self._read_and_parse([_HEADER_READV])
778
return self._key_count
780
def _lookup_keys_via_location(self, location_keys):
781
"""Public interface for implementing bisection.
783
If _buffer_all has been called, then all the data for the index is in
784
memory, and this method should not be called, as it uses a separate
785
cache because it cannot pre-resolve all indices, which buffer_all does
788
:param location_keys: A list of location(byte offset), key tuples.
789
:return: A list of (location_key, result) tuples as expected by
790
bzrlib.bisect_multi.bisect_multi_bytes.
792
# Possible improvements:
793
# - only bisect lookup each key once
794
# - sort the keys first, and use that to reduce the bisection window
796
# this progresses in three parts:
799
# attempt to answer the question from the now in memory data.
800
# build the readv request
801
# for each location, ask for 800 bytes - much more than rows we've seen
804
for location, key in location_keys:
805
# can we answer from cache?
806
if self._bisect_nodes and key in self._bisect_nodes:
807
# We have the key parsed.
809
index = self._parsed_key_index(key)
810
if (len(self._parsed_key_map) and
811
self._parsed_key_map[index][0] <= key and
812
(self._parsed_key_map[index][1] >= key or
813
# end of the file has been parsed
814
self._parsed_byte_map[index][1] == self._size)):
815
# the key has been parsed, so no lookup is needed even if its
818
# - if we have examined this part of the file already - yes
819
index = self._parsed_byte_index(location)
820
if (len(self._parsed_byte_map) and
821
self._parsed_byte_map[index][0] <= location and
822
self._parsed_byte_map[index][1] > location):
823
# the byte region has been parsed, so no read is needed.
826
if location + length > self._size:
827
length = self._size - location
828
# todo, trim out parsed locations.
830
readv_ranges.append((location, length))
831
# read the header if needed
832
if self._bisect_nodes is None:
833
readv_ranges.append(_HEADER_READV)
834
self._read_and_parse(readv_ranges)
836
if self._nodes is not None:
837
# _read_and_parse triggered a _buffer_all because we requested the
839
for location, key in location_keys:
840
if key not in self._nodes: # not present
841
result.append(((location, key), False))
842
elif self.node_ref_lists:
843
value, refs = self._nodes[key]
844
result.append(((location, key),
845
(self, key, value, refs)))
847
result.append(((location, key),
848
(self, key, self._nodes[key])))
851
# - figure out <, >, missing, present
852
# - result present references so we can return them.
853
# keys that we cannot answer until we resolve references
854
pending_references = []
855
pending_locations = set()
856
for location, key in location_keys:
857
# can we answer from cache?
858
if key in self._bisect_nodes:
859
# the key has been parsed, so no lookup is needed
860
if self.node_ref_lists:
861
# the references may not have been all parsed.
862
value, refs = self._bisect_nodes[key]
863
wanted_locations = []
864
for ref_list in refs:
866
if ref not in self._keys_by_offset:
867
wanted_locations.append(ref)
869
pending_locations.update(wanted_locations)
870
pending_references.append((location, key))
872
result.append(((location, key), (self, key,
873
value, self._resolve_references(refs))))
875
result.append(((location, key),
876
(self, key, self._bisect_nodes[key])))
879
# has the region the key should be in, been parsed?
880
index = self._parsed_key_index(key)
881
if (self._parsed_key_map[index][0] <= key and
882
(self._parsed_key_map[index][1] >= key or
883
# end of the file has been parsed
884
self._parsed_byte_map[index][1] == self._size)):
885
result.append(((location, key), False))
887
# no, is the key above or below the probed location:
888
# get the range of the probed & parsed location
889
index = self._parsed_byte_index(location)
890
# if the key is below the start of the range, its below
891
if key < self._parsed_key_map[index][0]:
895
result.append(((location, key), direction))
897
# lookup data to resolve references
898
for location in pending_locations:
900
if location + length > self._size:
901
length = self._size - location
902
# TODO: trim out parsed locations (e.g. if the 800 is into the
903
# parsed region trim it, and dont use the adjust_for_latency
906
readv_ranges.append((location, length))
907
self._read_and_parse(readv_ranges)
908
if self._nodes is not None:
909
# The _read_and_parse triggered a _buffer_all, grab the data and
911
for location, key in pending_references:
912
value, refs = self._nodes[key]
913
result.append(((location, key), (self, key, value, refs)))
915
for location, key in pending_references:
916
# answer key references we had to look-up-late.
917
value, refs = self._bisect_nodes[key]
918
result.append(((location, key), (self, key,
919
value, self._resolve_references(refs))))
922
def _parse_header_from_bytes(self, bytes):
923
"""Parse the header from a region of bytes.
925
:param bytes: The data to parse.
926
:return: An offset, data tuple such as readv yields, for the unparsed
927
data. (which may length 0).
929
signature = bytes[0:len(self._signature())]
930
if not signature == self._signature():
931
raise errors.BadIndexFormatSignature(self._name, GraphIndex)
932
lines = bytes[len(self._signature()):].splitlines()
933
options_line = lines[0]
934
if not options_line.startswith(_OPTION_NODE_REFS):
935
raise errors.BadIndexOptions(self)
937
self.node_ref_lists = int(options_line[len(_OPTION_NODE_REFS):])
939
raise errors.BadIndexOptions(self)
940
options_line = lines[1]
941
if not options_line.startswith(_OPTION_KEY_ELEMENTS):
942
raise errors.BadIndexOptions(self)
944
self._key_length = int(options_line[len(_OPTION_KEY_ELEMENTS):])
946
raise errors.BadIndexOptions(self)
947
options_line = lines[2]
948
if not options_line.startswith(_OPTION_LEN):
949
raise errors.BadIndexOptions(self)
951
self._key_count = int(options_line[len(_OPTION_LEN):])
953
raise errors.BadIndexOptions(self)
954
# calculate the bytes we have processed
955
header_end = (len(signature) + len(lines[0]) + len(lines[1]) +
957
self._parsed_bytes(0, None, header_end, None)
958
# setup parsing state
959
self._expected_elements = 3 + self._key_length
960
# raw data keyed by offset
961
self._keys_by_offset = {}
962
# keys with the value and node references
963
self._bisect_nodes = {}
964
return header_end, bytes[header_end:]
966
def _parse_region(self, offset, data):
967
"""Parse node data returned from a readv operation.
969
:param offset: The byte offset the data starts at.
970
:param data: The data to parse.
974
end = offset + len(data)
977
# Trivial test - if the current index's end is within the
978
# low-matching parsed range, we're done.
979
index = self._parsed_byte_index(high_parsed)
980
if end < self._parsed_byte_map[index][1]:
982
# print "[%d:%d]" % (offset, end), \
983
# self._parsed_byte_map[index:index + 2]
984
high_parsed, last_segment = self._parse_segment(
985
offset, data, end, index)
989
def _parse_segment(self, offset, data, end, index):
990
"""Parse one segment of data.
992
:param offset: Where 'data' begins in the file.
993
:param data: Some data to parse a segment of.
994
:param end: Where data ends
995
:param index: The current index into the parsed bytes map.
996
:return: True if the parsed segment is the last possible one in the
998
:return: high_parsed_byte, last_segment.
999
high_parsed_byte is the location of the highest parsed byte in this
1000
segment, last_segment is True if the parsed segment is the last
1001
possible one in the data block.
1003
# default is to use all data
1005
# accomodate overlap with data before this.
1006
if offset < self._parsed_byte_map[index][1]:
1007
# overlaps the lower parsed region
1008
# skip the parsed data
1009
trim_start = self._parsed_byte_map[index][1] - offset
1010
# don't trim the start for \n
1011
start_adjacent = True
1012
elif offset == self._parsed_byte_map[index][1]:
1013
# abuts the lower parsed region
1016
# do not trim anything
1017
start_adjacent = True
1019
# does not overlap the lower parsed region
1022
# but trim the leading \n
1023
start_adjacent = False
1024
if end == self._size:
1025
# lines up to the end of all data:
1028
# do not strip to the last \n
1031
elif index + 1 == len(self._parsed_byte_map):
1032
# at the end of the parsed data
1035
# but strip to the last \n
1036
end_adjacent = False
1038
elif end == self._parsed_byte_map[index + 1][0]:
1039
# buts up against the next parsed region
1042
# do not strip to the last \n
1045
elif end > self._parsed_byte_map[index + 1][0]:
1046
# overlaps into the next parsed region
1047
# only consider the unparsed data
1048
trim_end = self._parsed_byte_map[index + 1][0] - offset
1049
# do not strip to the last \n as we know its an entire record
1051
last_segment = end < self._parsed_byte_map[index + 1][1]
1053
# does not overlap into the next region
1056
# but strip to the last \n
1057
end_adjacent = False
1059
# now find bytes to discard if needed
1060
if not start_adjacent:
1061
# work around python bug in rfind
1062
if trim_start is None:
1063
trim_start = data.find('\n') + 1
1065
trim_start = data.find('\n', trim_start) + 1
1066
if not (trim_start != 0):
1067
raise AssertionError('no \n was present')
1068
# print 'removing start', offset, trim_start, repr(data[:trim_start])
1069
if not end_adjacent:
1070
# work around python bug in rfind
1071
if trim_end is None:
1072
trim_end = data.rfind('\n') + 1
1074
trim_end = data.rfind('\n', None, trim_end) + 1
1075
if not (trim_end != 0):
1076
raise AssertionError('no \n was present')
1077
# print 'removing end', offset, trim_end, repr(data[trim_end:])
1078
# adjust offset and data to the parseable data.
1079
trimmed_data = data[trim_start:trim_end]
1080
if not (trimmed_data):
1081
raise AssertionError('read unneeded data [%d:%d] from [%d:%d]'
1082
% (trim_start, trim_end, offset, offset + len(data)))
1084
offset += trim_start
1085
# print "parsing", repr(trimmed_data)
1086
# splitlines mangles the \r delimiters.. don't use it.
1087
lines = trimmed_data.split('\n')
1090
first_key, last_key, nodes, _ = self._parse_lines(lines, pos)
1091
for key, value in nodes:
1092
self._bisect_nodes[key] = value
1093
self._parsed_bytes(offset, first_key,
1094
offset + len(trimmed_data), last_key)
1095
return offset + len(trimmed_data), last_segment
1097
def _parse_lines(self, lines, pos):
1104
# must be at the end
1106
if not (self._size == pos + 1):
1107
raise AssertionError("%s %s" % (self._size, pos))
1110
elements = line.split('\0')
1111
if len(elements) != self._expected_elements:
1112
raise errors.BadIndexData(self)
1113
# keys are tuples. Each element is a string that may occur many
1114
# times, so we intern them to save space. AB, RC, 200807
1115
key = tuple([intern(element) for element in elements[:self._key_length]])
1116
if first_key is None:
1118
absent, references, value = elements[-3:]
1120
for ref_string in references.split('\t'):
1121
ref_lists.append(tuple([
1122
int(ref) for ref in ref_string.split('\r') if ref
1124
ref_lists = tuple(ref_lists)
1125
self._keys_by_offset[pos] = (key, absent, ref_lists, value)
1126
pos += len(line) + 1 # +1 for the \n
1129
if self.node_ref_lists:
1130
node_value = (value, ref_lists)
1133
nodes.append((key, node_value))
1134
# print "parsed ", key
1135
return first_key, key, nodes, trailers
1137
def _parsed_bytes(self, start, start_key, end, end_key):
1138
"""Mark the bytes from start to end as parsed.
1140
Calling self._parsed_bytes(1,2) will mark one byte (the one at offset
1143
:param start: The start of the parsed region.
1144
:param end: The end of the parsed region.
1146
index = self._parsed_byte_index(start)
1147
new_value = (start, end)
1148
new_key = (start_key, end_key)
1150
# first range parsed is always the beginning.
1151
self._parsed_byte_map.insert(index, new_value)
1152
self._parsed_key_map.insert(index, new_key)
1156
# extend lower region
1157
# extend higher region
1158
# combine two regions
1159
if (index + 1 < len(self._parsed_byte_map) and
1160
self._parsed_byte_map[index][1] == start and
1161
self._parsed_byte_map[index + 1][0] == end):
1162
# combine two regions
1163
self._parsed_byte_map[index] = (self._parsed_byte_map[index][0],
1164
self._parsed_byte_map[index + 1][1])
1165
self._parsed_key_map[index] = (self._parsed_key_map[index][0],
1166
self._parsed_key_map[index + 1][1])
1167
del self._parsed_byte_map[index + 1]
1168
del self._parsed_key_map[index + 1]
1169
elif self._parsed_byte_map[index][1] == start:
1170
# extend the lower entry
1171
self._parsed_byte_map[index] = (
1172
self._parsed_byte_map[index][0], end)
1173
self._parsed_key_map[index] = (
1174
self._parsed_key_map[index][0], end_key)
1175
elif (index + 1 < len(self._parsed_byte_map) and
1176
self._parsed_byte_map[index + 1][0] == end):
1177
# extend the higher entry
1178
self._parsed_byte_map[index + 1] = (
1179
start, self._parsed_byte_map[index + 1][1])
1180
self._parsed_key_map[index + 1] = (
1181
start_key, self._parsed_key_map[index + 1][1])
1184
self._parsed_byte_map.insert(index + 1, new_value)
1185
self._parsed_key_map.insert(index + 1, new_key)
1187
def _read_and_parse(self, readv_ranges):
1188
"""Read the ranges and parse the resulting data.
1190
:param readv_ranges: A prepared readv range list.
1192
if not readv_ranges:
1194
if self._nodes is None and self._bytes_read * 2 >= self._size:
1195
# We've already read more than 50% of the file and we are about to
1196
# request more data, just _buffer_all() and be done
1200
base_offset = self._base_offset
1201
if base_offset != 0:
1202
# Rewrite the ranges for the offset
1203
readv_ranges = [(start+base_offset, size)
1204
for start, size in readv_ranges]
1205
readv_data = self._transport.readv(self._name, readv_ranges, True,
1206
self._size + self._base_offset)
1208
for offset, data in readv_data:
1209
offset -= base_offset
1210
self._bytes_read += len(data)
1212
# transport.readv() expanded to extra data which isn't part of
1214
data = data[-offset:]
1216
if offset == 0 and len(data) == self._size:
1217
# We read the whole range, most likely because the
1218
# Transport upcast our readv ranges into one long request
1219
# for enough total data to grab the whole index.
1220
self._buffer_all(StringIO(data))
1222
if self._bisect_nodes is None:
1223
# this must be the start
1224
if not (offset == 0):
1225
raise AssertionError()
1226
offset, data = self._parse_header_from_bytes(data)
1227
# print readv_ranges, "[%d:%d]" % (offset, offset + len(data))
1228
self._parse_region(offset, data)
1230
def _signature(self):
1231
"""The file signature for this index type."""
1235
"""Validate that everything in the index can be accessed."""
1236
# iter_all validates completely at the moment, so just do that.
1237
for node in self.iter_all_entries():
1241
class CombinedGraphIndex(object):
1242
"""A GraphIndex made up from smaller GraphIndices.
1244
The backing indices must implement GraphIndex, and are presumed to be
1247
Queries against the combined index will be made against the first index,
1248
and then the second and so on. The order of indices can thus influence
1249
performance significantly. For example, if one index is on local disk and a
1250
second on a remote server, the local disk index should be before the other
1253
Also, queries tend to need results from the same indices as previous
1254
queries. So the indices will be reordered after every query to put the
1255
indices that had the result(s) of that query first (while otherwise
1256
preserving the relative ordering).
1259
def __init__(self, indices, reload_func=None):
1260
"""Create a CombinedGraphIndex backed by indices.
1262
:param indices: An ordered list of indices to query for data.
1263
:param reload_func: A function to call if we find we are missing an
1264
index. Should have the form reload_func() => True/False to indicate
1265
if reloading actually changed anything.
1267
self._indices = indices
1268
self._reload_func = reload_func
1269
# Sibling indices are other CombinedGraphIndex that we should call
1270
# _move_to_front_by_name on when we auto-reorder ourself.
1271
self._sibling_indices = []
1272
# A list of names that corresponds to the instances in self._indices,
1273
# so _index_names[0] is always the name for _indices[0], etc. Sibling
1274
# indices must all use the same set of names as each other.
1275
self._index_names = [None] * len(self._indices)
1279
self.__class__.__name__,
1280
', '.join(map(repr, self._indices)))
1282
def clear_cache(self):
1283
"""See GraphIndex.clear_cache()"""
1284
for index in self._indices:
1287
def get_parent_map(self, keys):
1288
"""See graph.StackedParentsProvider.get_parent_map"""
1289
search_keys = set(keys)
1290
if NULL_REVISION in search_keys:
1291
search_keys.discard(NULL_REVISION)
1292
found_parents = {NULL_REVISION:[]}
1295
for index, key, value, refs in self.iter_entries(search_keys):
1298
parents = (NULL_REVISION,)
1299
found_parents[key] = parents
1300
return found_parents
1302
has_key = _has_key_from_parent_map
1304
def insert_index(self, pos, index, name=None):
1305
"""Insert a new index in the list of indices to query.
1307
:param pos: The position to insert the index.
1308
:param index: The index to insert.
1309
:param name: a name for this index, e.g. a pack name. These names can
1310
be used to reflect index reorderings to related CombinedGraphIndex
1311
instances that use the same names. (see set_sibling_indices)
1313
self._indices.insert(pos, index)
1314
self._index_names.insert(pos, name)
1316
def iter_all_entries(self):
1317
"""Iterate over all keys within the index
1319
Duplicate keys across child indices are presumed to have the same
1320
value and are only reported once.
1322
:return: An iterable of (index, key, reference_lists, value).
1323
There is no defined order for the result iteration - it will be in
1324
the most efficient order for the index.
1329
for index in self._indices:
1330
for node in index.iter_all_entries():
1331
if node[1] not in seen_keys:
1333
seen_keys.add(node[1])
1335
except errors.NoSuchFile:
1336
self._reload_or_raise()
1338
def iter_entries(self, keys):
1339
"""Iterate over keys within the index.
1341
Duplicate keys across child indices are presumed to have the same
1342
value and are only reported once.
1344
:param keys: An iterable providing the keys to be retrieved.
1345
:return: An iterable of (index, key, reference_lists, value). There is
1346
no defined order for the result iteration - it will be in the most
1347
efficient order for the index.
1353
for index in self._indices:
1357
for node in index.iter_entries(keys):
1358
keys.remove(node[1])
1362
hit_indices.append(index)
1364
except errors.NoSuchFile:
1365
self._reload_or_raise()
1366
self._move_to_front(hit_indices)
1368
def iter_entries_prefix(self, keys):
1369
"""Iterate over keys within the index using prefix matching.
1371
Duplicate keys across child indices are presumed to have the same
1372
value and are only reported once.
1374
Prefix matching is applied within the tuple of a key, not to within
1375
the bytestring of each key element. e.g. if you have the keys ('foo',
1376
'bar'), ('foobar', 'gam') and do a prefix search for ('foo', None) then
1377
only the former key is returned.
1379
:param keys: An iterable providing the key prefixes to be retrieved.
1380
Each key prefix takes the form of a tuple the length of a key, but
1381
with the last N elements 'None' rather than a regular bytestring.
1382
The first element cannot be 'None'.
1383
:return: An iterable as per iter_all_entries, but restricted to the
1384
keys with a matching prefix to those supplied. No additional keys
1385
will be returned, and every match that is in the index will be
1395
for index in self._indices:
1397
for node in index.iter_entries_prefix(keys):
1398
if node[1] in seen_keys:
1400
seen_keys.add(node[1])
1404
hit_indices.append(index)
1406
except errors.NoSuchFile:
1407
self._reload_or_raise()
1408
self._move_to_front(hit_indices)
1410
def _move_to_front(self, hit_indices):
1411
"""Rearrange self._indices so that hit_indices are first.
1413
Order is maintained as much as possible, e.g. the first unhit index
1414
will be the first index in _indices after the hit_indices, and the
1415
hit_indices will be present in exactly the order they are passed to
1418
_move_to_front propagates to all objects in self._sibling_indices by
1419
calling _move_to_front_by_name.
1421
hit_names = self._move_to_front_by_index(hit_indices)
1422
for sibling_idx in self._sibling_indices:
1423
sibling_idx._move_to_front_by_name(hit_names)
1425
def _move_to_front_by_index(self, hit_indices):
1426
"""Core logic for _move_to_front.
1428
Returns a list of names corresponding to the hit_indices param.
1430
indices_info = zip(self._index_names, self._indices)
1431
if 'index' in debug.debug_flags:
1432
mutter('CombinedGraphIndex reordering: currently %r, promoting %r',
1433
indices_info, hit_indices)
1434
hit_indices_info = []
1436
unhit_indices_info = []
1437
for name, idx in indices_info:
1438
if idx in hit_indices:
1439
info = hit_indices_info
1440
hit_names.append(name)
1442
info = unhit_indices_info
1443
info.append((name, idx))
1444
final_info = hit_indices_info + unhit_indices_info
1445
self._indices = [idx for (name, idx) in final_info]
1446
self._index_names = [name for (name, idx) in final_info]
1447
if 'index' in debug.debug_flags:
1448
mutter('CombinedGraphIndex reordered: %r', self._indices)
1451
def _move_to_front_by_name(self, hit_names):
1452
"""Moves indices named by 'hit_names' to front of the search order, as
1453
described in _move_to_front.
1455
# Translate names to index instances, and then call
1456
# _move_to_front_by_index.
1457
indices_info = zip(self._index_names, self._indices)
1459
for name, idx in indices_info:
1460
if name in hit_names:
1461
hit_indices.append(idx)
1462
self._move_to_front_by_index(hit_indices)
1464
def find_ancestry(self, keys, ref_list_num):
1465
"""Find the complete ancestry for the given set of keys.
1467
Note that this is a whole-ancestry request, so it should be used
1470
:param keys: An iterable of keys to look for
1471
:param ref_list_num: The reference list which references the parents
1473
:return: (parent_map, missing_keys)
1475
# XXX: make this call _move_to_front?
1476
missing_keys = set()
1478
keys_to_lookup = set(keys)
1480
while keys_to_lookup:
1481
# keys that *all* indexes claim are missing, stop searching them
1483
all_index_missing = None
1484
# print 'gen\tidx\tsub\tn_keys\tn_pmap\tn_miss'
1485
# print '%4d\t\t\t%4d\t%5d\t%5d' % (generation, len(keys_to_lookup),
1487
# len(missing_keys))
1488
for index_idx, index in enumerate(self._indices):
1489
# TODO: we should probably be doing something with
1490
# 'missing_keys' since we've already determined that
1491
# those revisions have not been found anywhere
1492
index_missing_keys = set()
1493
# Find all of the ancestry we can from this index
1494
# keep looking until the search_keys set is empty, which means
1495
# things we didn't find should be in index_missing_keys
1496
search_keys = keys_to_lookup
1498
# print ' \t%2d\t\t%4d\t%5d\t%5d' % (
1499
# index_idx, len(search_keys),
1500
# len(parent_map), len(index_missing_keys))
1503
# TODO: ref_list_num should really be a parameter, since
1504
# CombinedGraphIndex does not know what the ref lists
1506
search_keys = index._find_ancestors(search_keys,
1507
ref_list_num, parent_map, index_missing_keys)
1508
# print ' \t \t%2d\t%4d\t%5d\t%5d' % (
1509
# sub_generation, len(search_keys),
1510
# len(parent_map), len(index_missing_keys))
1511
# Now set whatever was missing to be searched in the next index
1512
keys_to_lookup = index_missing_keys
1513
if all_index_missing is None:
1514
all_index_missing = set(index_missing_keys)
1516
all_index_missing.intersection_update(index_missing_keys)
1517
if not keys_to_lookup:
1519
if all_index_missing is None:
1520
# There were no indexes, so all search keys are 'missing'
1521
missing_keys.update(keys_to_lookup)
1522
keys_to_lookup = None
1524
missing_keys.update(all_index_missing)
1525
keys_to_lookup.difference_update(all_index_missing)
1526
return parent_map, missing_keys
1528
def key_count(self):
1529
"""Return an estimate of the number of keys in this index.
1531
For CombinedGraphIndex this is approximated by the sum of the keys of
1532
the child indices. As child indices may have duplicate keys this can
1533
have a maximum error of the number of child indices * largest number of
1538
return sum((index.key_count() for index in self._indices), 0)
1539
except errors.NoSuchFile:
1540
self._reload_or_raise()
1542
missing_keys = _missing_keys_from_parent_map
1544
def _reload_or_raise(self):
1545
"""We just got a NoSuchFile exception.
1547
Try to reload the indices, if it fails, just raise the current
1550
if self._reload_func is None:
1552
exc_type, exc_value, exc_traceback = sys.exc_info()
1553
trace.mutter('Trying to reload after getting exception: %s',
1555
if not self._reload_func():
1556
# We tried to reload, but nothing changed, so we fail anyway
1557
trace.mutter('_reload_func indicated nothing has changed.'
1558
' Raising original exception.')
1559
raise exc_type, exc_value, exc_traceback
1561
def set_sibling_indices(self, sibling_combined_graph_indices):
1562
"""Set the CombinedGraphIndex objects to reorder after reordering self.
1564
self._sibling_indices = sibling_combined_graph_indices
1567
"""Validate that everything in the index can be accessed."""
1570
for index in self._indices:
1573
except errors.NoSuchFile:
1574
self._reload_or_raise()
1577
class InMemoryGraphIndex(GraphIndexBuilder):
1578
"""A GraphIndex which operates entirely out of memory and is mutable.
1580
This is designed to allow the accumulation of GraphIndex entries during a
1581
single write operation, where the accumulated entries need to be immediately
1582
available - for example via a CombinedGraphIndex.
1585
def add_nodes(self, nodes):
1586
"""Add nodes to the index.
1588
:param nodes: An iterable of (key, node_refs, value) entries to add.
1590
if self.reference_lists:
1591
for (key, value, node_refs) in nodes:
1592
self.add_node(key, value, node_refs)
1594
for (key, value) in nodes:
1595
self.add_node(key, value)
1597
def iter_all_entries(self):
1598
"""Iterate over all keys within the index
1600
:return: An iterable of (index, key, reference_lists, value). There is no
1601
defined order for the result iteration - it will be in the most
1602
efficient order for the index (in this case dictionary hash order).
1604
if 'evil' in debug.debug_flags:
1605
trace.mutter_callsite(3,
1606
"iter_all_entries scales with size of history.")
1607
if self.reference_lists:
1608
for key, (absent, references, value) in self._nodes.iteritems():
1610
yield self, key, value, references
1612
for key, (absent, references, value) in self._nodes.iteritems():
1614
yield self, key, value
1616
def iter_entries(self, keys):
1617
"""Iterate over keys within the index.
1619
:param keys: An iterable providing the keys to be retrieved.
1620
:return: An iterable of (index, key, value, reference_lists). There is no
1621
defined order for the result iteration - it will be in the most
1622
efficient order for the index (keys iteration order in this case).
1624
# Note: See BTreeBuilder.iter_entries for an explanation of why we
1625
# aren't using set().intersection() here
1627
keys = [key for key in keys if key in nodes]
1628
if self.reference_lists:
1632
yield self, key, node[2], node[1]
1637
yield self, key, node[2]
1639
def iter_entries_prefix(self, keys):
1640
"""Iterate over keys within the index using prefix matching.
1642
Prefix matching is applied within the tuple of a key, not to within
1643
the bytestring of each key element. e.g. if you have the keys ('foo',
1644
'bar'), ('foobar', 'gam') and do a prefix search for ('foo', None) then
1645
only the former key is returned.
1647
:param keys: An iterable providing the key prefixes to be retrieved.
1648
Each key prefix takes the form of a tuple the length of a key, but
1649
with the last N elements 'None' rather than a regular bytestring.
1650
The first element cannot be 'None'.
1651
:return: An iterable as per iter_all_entries, but restricted to the
1652
keys with a matching prefix to those supplied. No additional keys
1653
will be returned, and every match that is in the index will be
1656
# XXX: To much duplication with the GraphIndex class; consider finding
1657
# a good place to pull out the actual common logic.
1661
if self._key_length == 1:
1665
raise errors.BadIndexKey(key)
1666
if len(key) != self._key_length:
1667
raise errors.BadIndexKey(key)
1668
node = self._nodes[key]
1671
if self.reference_lists:
1672
yield self, key, node[2], node[1]
1674
yield self, key, node[2]
1676
nodes_by_key = self._get_nodes_by_key()
1680
raise errors.BadIndexKey(key)
1681
if len(key) != self._key_length:
1682
raise errors.BadIndexKey(key)
1683
# find what it refers to:
1684
key_dict = nodes_by_key
1685
elements = list(key)
1686
# find the subdict to return
1688
while len(elements) and elements[0] is not None:
1689
key_dict = key_dict[elements[0]]
1692
# a non-existant lookup.
1697
key_dict = dicts.pop(-1)
1698
# can't be empty or would not exist
1699
item, value = key_dict.iteritems().next()
1700
if type(value) == dict:
1702
dicts.extend(key_dict.itervalues())
1705
for value in key_dict.itervalues():
1706
yield (self, ) + value
1708
yield (self, ) + key_dict
1710
def key_count(self):
1711
"""Return an estimate of the number of keys in this index.
1713
For InMemoryGraphIndex the estimate is exact.
1715
return len(self._nodes) - len(self._absent_keys)
1718
"""In memory index's have no known corruption at the moment."""
1721
class GraphIndexPrefixAdapter(object):
1722
"""An adapter between GraphIndex with different key lengths.
1724
Queries against this will emit queries against the adapted Graph with the
1725
prefix added, queries for all items use iter_entries_prefix. The returned
1726
nodes will have their keys and node references adjusted to remove the
1727
prefix. Finally, an add_nodes_callback can be supplied - when called the
1728
nodes and references being added will have prefix prepended.
1731
def __init__(self, adapted, prefix, missing_key_length,
1732
add_nodes_callback=None):
1733
"""Construct an adapter against adapted with prefix."""
1734
self.adapted = adapted
1735
self.prefix_key = prefix + (None,)*missing_key_length
1736
self.prefix = prefix
1737
self.prefix_len = len(prefix)
1738
self.add_nodes_callback = add_nodes_callback
1740
def add_nodes(self, nodes):
1741
"""Add nodes to the index.
1743
:param nodes: An iterable of (key, node_refs, value) entries to add.
1745
# save nodes in case its an iterator
1746
nodes = tuple(nodes)
1747
translated_nodes = []
1749
# Add prefix_key to each reference node_refs is a tuple of tuples,
1750
# so split it apart, and add prefix_key to the internal reference
1751
for (key, value, node_refs) in nodes:
1752
adjusted_references = (
1753
tuple(tuple(self.prefix + ref_node for ref_node in ref_list)
1754
for ref_list in node_refs))
1755
translated_nodes.append((self.prefix + key, value,
1756
adjusted_references))
1758
# XXX: TODO add an explicit interface for getting the reference list
1759
# status, to handle this bit of user-friendliness in the API more
1761
for (key, value) in nodes:
1762
translated_nodes.append((self.prefix + key, value))
1763
self.add_nodes_callback(translated_nodes)
1765
def add_node(self, key, value, references=()):
1766
"""Add a node to the index.
1768
:param key: The key. keys are non-empty tuples containing
1769
as many whitespace-free utf8 bytestrings as the key length
1770
defined for this index.
1771
:param references: An iterable of iterables of keys. Each is a
1772
reference to another key.
1773
:param value: The value to associate with the key. It may be any
1774
bytes as long as it does not contain \0 or \n.
1776
self.add_nodes(((key, value, references), ))
1778
def _strip_prefix(self, an_iter):
1779
"""Strip prefix data from nodes and return it."""
1780
for node in an_iter:
1782
if node[1][:self.prefix_len] != self.prefix:
1783
raise errors.BadIndexData(self)
1784
for ref_list in node[3]:
1785
for ref_node in ref_list:
1786
if ref_node[:self.prefix_len] != self.prefix:
1787
raise errors.BadIndexData(self)
1788
yield node[0], node[1][self.prefix_len:], node[2], (
1789
tuple(tuple(ref_node[self.prefix_len:] for ref_node in ref_list)
1790
for ref_list in node[3]))
1792
def iter_all_entries(self):
1793
"""Iterate over all keys within the index
1795
iter_all_entries is implemented against the adapted index using
1796
iter_entries_prefix.
1798
:return: An iterable of (index, key, reference_lists, value). There is no
1799
defined order for the result iteration - it will be in the most
1800
efficient order for the index (in this case dictionary hash order).
1802
return self._strip_prefix(self.adapted.iter_entries_prefix([self.prefix_key]))
1804
def iter_entries(self, keys):
1805
"""Iterate over keys within the index.
1807
:param keys: An iterable providing the keys to be retrieved.
1808
:return: An iterable of (index, key, value, reference_lists). There is no
1809
defined order for the result iteration - it will be in the most
1810
efficient order for the index (keys iteration order in this case).
1812
return self._strip_prefix(self.adapted.iter_entries(
1813
self.prefix + key for key in keys))
1815
def iter_entries_prefix(self, keys):
1816
"""Iterate over keys within the index using prefix matching.
1818
Prefix matching is applied within the tuple of a key, not to within
1819
the bytestring of each key element. e.g. if you have the keys ('foo',
1820
'bar'), ('foobar', 'gam') and do a prefix search for ('foo', None) then
1821
only the former key is returned.
1823
:param keys: An iterable providing the key prefixes to be retrieved.
1824
Each key prefix takes the form of a tuple the length of a key, but
1825
with the last N elements 'None' rather than a regular bytestring.
1826
The first element cannot be 'None'.
1827
:return: An iterable as per iter_all_entries, but restricted to the
1828
keys with a matching prefix to those supplied. No additional keys
1829
will be returned, and every match that is in the index will be
1832
return self._strip_prefix(self.adapted.iter_entries_prefix(
1833
self.prefix + key for key in keys))
1835
def key_count(self):
1836
"""Return an estimate of the number of keys in this index.
1838
For GraphIndexPrefixAdapter this is relatively expensive - key
1839
iteration with the prefix is done.
1841
return len(list(self.iter_all_entries()))
1844
"""Call the adapted's validate."""
1845
self.adapted.validate()
added
removed
bzrlib/index.py
