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# Copyright (C) 2008, 2009 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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"""Core compression logic for compressing streams of related files."""
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from itertools import izip
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from cStringIO import StringIO
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from bzrlib.graph import Graph
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from bzrlib.btree_index import BTreeBuilder
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from bzrlib.lru_cache import LRUSizeCache
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from bzrlib.tsort import topo_sort
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from bzrlib.versionedfile import (
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ChunkedContentFactory,
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FulltextContentFactory,
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_USE_LZMA = False and (pylzma is not None)
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# osutils.sha_string('')
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_null_sha1 = 'da39a3ee5e6b4b0d3255bfef95601890afd80709'
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def sort_gc_optimal(parent_map):
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"""Sort and group the keys in parent_map into groupcompress order.
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groupcompress is defined (currently) as reverse-topological order, grouped
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:return: A sorted-list of keys
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# groupcompress ordering is approximately reverse topological,
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# properly grouped by file-id.
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for item in parent_map.iteritems():
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if isinstance(key, str) or len(key) == 1:
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per_prefix_map[prefix].append(item)
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per_prefix_map[prefix] = [item]
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for prefix in sorted(per_prefix_map):
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present_keys.extend(reversed(topo_sort(per_prefix_map[prefix])))
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# The max zlib window size is 32kB, so if we set 'max_size' output of the
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# decompressor to the requested bytes + 32kB, then we should guarantee
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# num_bytes coming out.
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_ZLIB_DECOMP_WINDOW = 32*1024
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class GroupCompressBlock(object):
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"""An object which maintains the internal structure of the compressed data.
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This tracks the meta info (start of text, length, type, etc.)
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# Group Compress Block v1 Zlib
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GCB_HEADER = 'gcb1z\n'
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# Group Compress Block v1 Lzma
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GCB_LZ_HEADER = 'gcb1l\n'
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GCB_KNOWN_HEADERS = (GCB_HEADER, GCB_LZ_HEADER)
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# map by key? or just order in file?
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self._compressor_name = None
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self._z_content = None
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self._z_content_decompressor = None
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self._z_content_length = None
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self._content_length = None
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# This is the maximum number of bytes this object will reference if
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# everything is decompressed. However, if we decompress less than
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# everything... (this would cause some problems for LRUSizeCache)
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return self._content_length + self._z_content_length
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def _ensure_content(self, num_bytes=None):
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"""Make sure that content has been expanded enough.
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:param num_bytes: Ensure that we have extracted at least num_bytes of
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content. If None, consume everything
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# TODO: If we re-use the same content block at different times during
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# get_record_stream(), it is possible that the first pass will
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# get inserted, triggering an extract/_ensure_content() which
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# will get rid of _z_content. And then the next use of the block
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# will try to access _z_content (to send it over the wire), and
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# fail because it is already extracted. Consider never releasing
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# _z_content because of this.
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if num_bytes is None:
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num_bytes = self._content_length
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elif (self._content_length is not None
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and num_bytes > self._content_length):
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raise AssertionError(
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'requested num_bytes (%d) > content length (%d)'
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% (num_bytes, self._content_length))
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# Expand the content if required
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if self._content is None:
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if self._z_content is None:
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raise AssertionError('No content to decompress')
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if self._z_content == '':
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elif self._compressor_name == 'lzma':
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# We don't do partial lzma decomp yet
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self._content = pylzma.decompress(self._z_content)
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elif self._compressor_name == 'zlib':
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# Start a zlib decompressor
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if num_bytes is None:
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self._content = zlib.decompress(self._z_content)
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self._z_content_decompressor = zlib.decompressobj()
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# Seed the decompressor with the uncompressed bytes, so
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# that the rest of the code is simplified
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self._content = self._z_content_decompressor.decompress(
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self._z_content, num_bytes + _ZLIB_DECOMP_WINDOW)
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raise AssertionError('Unknown compressor: %r'
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% self._compressor_name)
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# Any bytes remaining to be decompressed will be in the decompressors
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# Do we have enough bytes already?
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if num_bytes is not None and len(self._content) >= num_bytes:
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if num_bytes is None and self._z_content_decompressor is None:
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# We must have already decompressed everything
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# If we got this far, and don't have a decompressor, something is wrong
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if self._z_content_decompressor is None:
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raise AssertionError(
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'No decompressor to decompress %d bytes' % num_bytes)
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remaining_decomp = self._z_content_decompressor.unconsumed_tail
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if num_bytes is None:
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# We don't know how much is left, but we'll decompress it all
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self._content += self._z_content_decompressor.decompress(
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# Note: There's what I consider a bug in zlib.decompressobj
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# If you pass back in the entire unconsumed_tail, only
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# this time you don't pass a max-size, it doesn't
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# change the unconsumed_tail back to None/''.
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# However, we know we are done with the whole stream
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self._z_content_decompressor = None
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# XXX: Why is this the only place in this routine we set this?
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self._content_length = len(self._content)
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if not remaining_decomp:
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raise AssertionError('Nothing left to decompress')
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needed_bytes = num_bytes - len(self._content)
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# We always set max_size to 32kB over the minimum needed, so that
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# zlib will give us as much as we really want.
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# TODO: If this isn't good enough, we could make a loop here,
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# that keeps expanding the request until we get enough
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self._content += self._z_content_decompressor.decompress(
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remaining_decomp, needed_bytes + _ZLIB_DECOMP_WINDOW)
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if len(self._content) < num_bytes:
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raise AssertionError('%d bytes wanted, only %d available'
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% (num_bytes, len(self._content)))
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if not self._z_content_decompressor.unconsumed_tail:
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# The stream is finished
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self._z_content_decompressor = None
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def _parse_bytes(self, bytes, pos):
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"""Read the various lengths from the header.
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This also populates the various 'compressed' buffers.
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:return: The position in bytes just after the last newline
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# At present, we have 2 integers for the compressed and uncompressed
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# content. In base10 (ascii) 14 bytes can represent > 1TB, so to avoid
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# checking too far, cap the search to 14 bytes.
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pos2 = bytes.index('\n', pos, pos + 14)
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self._z_content_length = int(bytes[pos:pos2])
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pos2 = bytes.index('\n', pos, pos + 14)
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self._content_length = int(bytes[pos:pos2])
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if len(bytes) != (pos + self._z_content_length):
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# XXX: Define some GCCorrupt error ?
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raise AssertionError('Invalid bytes: (%d) != %d + %d' %
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(len(bytes), pos, self._z_content_length))
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self._z_content = bytes[pos:]
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def from_bytes(cls, bytes):
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if bytes[:6] not in cls.GCB_KNOWN_HEADERS:
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raise ValueError('bytes did not start with any of %r'
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% (cls.GCB_KNOWN_HEADERS,))
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# XXX: why not testing the whole header ?
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out._compressor_name = 'zlib'
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elif bytes[4] == 'l':
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out._compressor_name = 'lzma'
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raise ValueError('unknown compressor: %r' % (bytes,))
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out._parse_bytes(bytes, 6)
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def extract(self, key, start, end, sha1=None):
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"""Extract the text for a specific key.
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:param key: The label used for this content
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:param sha1: TODO (should we validate only when sha1 is supplied?)
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:return: The bytes for the content
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if start == end == 0:
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self._ensure_content(end)
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# The bytes are 'f' or 'd' for the type, then a variable-length
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# base128 integer for the content size, then the actual content
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# We know that the variable-length integer won't be longer than 5
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# bytes (it takes 5 bytes to encode 2^32)
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c = self._content[start]
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raise ValueError('Unknown content control code: %s'
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content_len, len_len = decode_base128_int(
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self._content[start + 1:start + 6])
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content_start = start + 1 + len_len
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if end != content_start + content_len:
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raise ValueError('end != len according to field header'
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' %s != %s' % (end, content_start + content_len))
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bytes = self._content[content_start:end]
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bytes = apply_delta_to_source(self._content, content_start, end)
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def set_content(self, content):
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"""Set the content of this block."""
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self._content_length = len(content)
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self._content = content
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self._z_content = None
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"""Encode the information into a byte stream."""
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compress = zlib.compress
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compress = pylzma.compress
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if self._z_content is None:
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if self._content is None:
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raise AssertionError('Nothing to compress')
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self._z_content = compress(self._content)
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self._z_content_length = len(self._z_content)
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header = self.GCB_LZ_HEADER
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header = self.GCB_HEADER
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'%d\n%d\n' % (self._z_content_length, self._content_length),
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return ''.join(chunks)
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def _dump(self, include_text=False):
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"""Take this block, and spit out a human-readable structure.
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:param include_text: Inserts also include text bits, chose whether you
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want this displayed in the dump or not.
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:return: A dump of the given block. The layout is something like:
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[('f', length), ('d', delta_length, text_length, [delta_info])]
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delta_info := [('i', num_bytes, text), ('c', offset, num_bytes),
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self._ensure_content()
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while pos < self._content_length:
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kind = self._content[pos]
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if kind not in ('f', 'd'):
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raise ValueError('invalid kind character: %r' % (kind,))
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content_len, len_len = decode_base128_int(
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self._content[pos:pos + 5])
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if content_len + pos > self._content_length:
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raise ValueError('invalid content_len %d for record @ pos %d'
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% (content_len, pos - len_len - 1))
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if kind == 'f': # Fulltext
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text = self._content[pos:pos+content_len]
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result.append(('f', content_len, text))
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result.append(('f', content_len))
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elif kind == 'd': # Delta
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delta_content = self._content[pos:pos+content_len]
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# The first entry in a delta is the decompressed length
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decomp_len, delta_pos = decode_base128_int(delta_content)
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result.append(('d', content_len, decomp_len, delta_info))
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while delta_pos < content_len:
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c = ord(delta_content[delta_pos])
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delta_pos) = decode_copy_instruction(delta_content, c,
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text = self._content[offset:offset+length]
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delta_info.append(('c', offset, length, text))
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delta_info.append(('c', offset, length))
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measured_len += length
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txt = delta_content[delta_pos:delta_pos+c]
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delta_info.append(('i', c, txt))
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if delta_pos != content_len:
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raise ValueError('Delta consumed a bad number of bytes:'
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' %d != %d' % (delta_pos, content_len))
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if measured_len != decomp_len:
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raise ValueError('Delta claimed fulltext was %d bytes, but'
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' extraction resulted in %d bytes'
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% (decomp_len, measured_len))
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class _LazyGroupCompressFactory(object):
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"""Yield content from a GroupCompressBlock on demand."""
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def __init__(self, key, parents, manager, start, end, first):
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"""Create a _LazyGroupCompressFactory
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:param key: The key of just this record
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:param parents: The parents of this key (possibly None)
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:param gc_block: A GroupCompressBlock object
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:param start: Offset of the first byte for this record in the
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:param end: Offset of the byte just after the end of this record
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(ie, bytes = content[start:end])
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:param first: Is this the first Factory for the given block?
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self.parents = parents
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# Note: This attribute coupled with Manager._factories creates a
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# reference cycle. Perhaps we would rather use a weakref(), or
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# find an appropriate time to release the ref. After the first
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# get_bytes_as call? After Manager.get_record_stream() returns
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self._manager = manager
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self.storage_kind = 'groupcompress-block'
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self.storage_kind = 'groupcompress-block-ref'
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return '%s(%s, first=%s)' % (self.__class__.__name__,
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self.key, self._first)
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def get_bytes_as(self, storage_kind):
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if storage_kind == self.storage_kind:
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# wire bytes, something...
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return self._manager._wire_bytes()
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if storage_kind in ('fulltext', 'chunked'):
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if self._bytes is None:
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# Grab and cache the raw bytes for this entry
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# and break the ref-cycle with _manager since we don't need it
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self._manager._prepare_for_extract()
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block = self._manager._block
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self._bytes = block.extract(self.key, self._start, self._end)
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# There are code paths that first extract as fulltext, and then
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# extract as storage_kind (smart fetch). So we don't break the
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# refcycle here, but instead in manager.get_record_stream()
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# self._manager = None
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if storage_kind == 'fulltext':
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raise errors.UnavailableRepresentation(self.key, storage_kind,
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class _LazyGroupContentManager(object):
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"""This manages a group of _LazyGroupCompressFactory objects."""
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def __init__(self, block):
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# We need to preserve the ordering
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def add_factory(self, key, parents, start, end):
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if not self._factories:
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# Note that this creates a reference cycle....
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factory = _LazyGroupCompressFactory(key, parents, self,
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start, end, first=first)
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# max() works here, but as a function call, doing a compare seems to be
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# significantly faster, timeit says 250ms for max() and 100ms for the
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if end > self._last_byte:
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self._last_byte = end
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self._factories.append(factory)
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def get_record_stream(self):
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"""Get a record for all keys added so far."""
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for factory in self._factories:
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# Break the ref-cycle
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factory._bytes = None
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factory._manager = None
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# TODO: Consider setting self._factories = None after the above loop,
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# as it will break the reference cycle
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def _trim_block(self, last_byte):
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"""Create a new GroupCompressBlock, with just some of the content."""
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# None of the factories need to be adjusted, because the content is
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# located in an identical place. Just that some of the unreferenced
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# trailing bytes are stripped
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trace.mutter('stripping trailing bytes from groupcompress block'
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' %d => %d', self._block._content_length, last_byte)
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new_block = GroupCompressBlock()
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self._block._ensure_content(last_byte)
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new_block.set_content(self._block._content[:last_byte])
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self._block = new_block
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def _rebuild_block(self):
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"""Create a new GroupCompressBlock with only the referenced texts."""
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compressor = GroupCompressor()
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old_length = self._block._content_length
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for factory in self._factories:
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bytes = factory.get_bytes_as('fulltext')
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(found_sha1, start_point, end_point,
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type) = compressor.compress(factory.key, bytes, factory.sha1)
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# Now update this factory with the new offsets, etc
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factory.sha1 = found_sha1
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factory._start = start_point
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factory._end = end_point
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self._last_byte = end_point
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new_block = compressor.flush()
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# TODO: Should we check that new_block really *is* smaller than the old
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# block? It seems hard to come up with a method that it would
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# expand, since we do full compression again. Perhaps based on a
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# request that ends up poorly ordered?
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delta = time.time() - tstart
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self._block = new_block
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trace.mutter('creating new compressed block on-the-fly in %.3fs'
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' %d bytes => %d bytes', delta, old_length,
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self._block._content_length)
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def _prepare_for_extract(self):
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"""A _LazyGroupCompressFactory is about to extract to fulltext."""
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# We expect that if one child is going to fulltext, all will be. This
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# helps prevent all of them from extracting a small amount at a time.
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# Which in itself isn't terribly expensive, but resizing 2MB 32kB at a
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# time (self._block._content) is a little expensive.
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self._block._ensure_content(self._last_byte)
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def _check_rebuild_block(self):
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"""Check to see if our block should be repacked."""
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for factory in self._factories:
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total_bytes_used += factory._end - factory._start
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last_byte_used = max(last_byte_used, factory._end)
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# If we are using most of the bytes from the block, we have nothing
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# else to check (currently more that 1/2)
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if total_bytes_used * 2 >= self._block._content_length:
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# Can we just strip off the trailing bytes? If we are going to be
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# transmitting more than 50% of the front of the content, go ahead
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if total_bytes_used * 2 > last_byte_used:
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self._trim_block(last_byte_used)
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# We are using a small amount of the data, and it isn't just packed
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# nicely at the front, so rebuild the content.
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# Note: This would be *nicer* as a strip-data-from-group, rather than
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# building it up again from scratch
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# It might be reasonable to consider the fulltext sizes for
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# different bits when deciding this, too. As you may have a small
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# fulltext, and a trivial delta, and you are just trading around
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# for another fulltext. If we do a simple 'prune' you may end up
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# expanding many deltas into fulltexts, as well.
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# If we build a cheap enough 'strip', then we could try a strip,
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# if that expands the content, we then rebuild.
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self._rebuild_block()
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def _wire_bytes(self):
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"""Return a byte stream suitable for transmitting over the wire."""
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self._check_rebuild_block()
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# The outer block starts with:
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# 'groupcompress-block\n'
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# <length of compressed key info>\n
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# <length of uncompressed info>\n
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# <length of gc block>\n
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lines = ['groupcompress-block\n']
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# The minimal info we need is the key, the start offset, and the
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# parents. The length and type are encoded in the record itself.
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# However, passing in the other bits makes it easier. The list of
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# keys, and the start offset, the length
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# 1 line with parents, '' for ()
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# 1 line for start offset
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# 1 line for end byte
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for factory in self._factories:
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key_bytes = '\x00'.join(factory.key)
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parents = factory.parents
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parent_bytes = 'None:'
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parent_bytes = '\t'.join('\x00'.join(key) for key in parents)
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record_header = '%s\n%s\n%d\n%d\n' % (
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key_bytes, parent_bytes, factory._start, factory._end)
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header_lines.append(record_header)
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# TODO: Can we break the refcycle at this point and set
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# factory._manager = None?
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header_bytes = ''.join(header_lines)
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header_bytes_len = len(header_bytes)
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z_header_bytes = zlib.compress(header_bytes)
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z_header_bytes_len = len(z_header_bytes)
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block_bytes = self._block.to_bytes()
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lines.append('%d\n%d\n%d\n' % (z_header_bytes_len, header_bytes_len,
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lines.append(z_header_bytes)
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lines.append(block_bytes)
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del z_header_bytes, block_bytes
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return ''.join(lines)
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def from_bytes(cls, bytes):
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# TODO: This does extra string copying, probably better to do it a
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(storage_kind, z_header_len, header_len,
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block_len, rest) = bytes.split('\n', 4)
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if storage_kind != 'groupcompress-block':
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raise ValueError('Unknown storage kind: %s' % (storage_kind,))
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z_header_len = int(z_header_len)
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if len(rest) < z_header_len:
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raise ValueError('Compressed header len shorter than all bytes')
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z_header = rest[:z_header_len]
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header_len = int(header_len)
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header = zlib.decompress(z_header)
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if len(header) != header_len:
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raise ValueError('invalid length for decompressed bytes')
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block_len = int(block_len)
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if len(rest) != z_header_len + block_len:
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raise ValueError('Invalid length for block')
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block_bytes = rest[z_header_len:]
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# So now we have a valid GCB, we just need to parse the factories that
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header_lines = header.split('\n')
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last = header_lines.pop()
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raise ValueError('header lines did not end with a trailing'
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if len(header_lines) % 4 != 0:
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raise ValueError('The header was not an even multiple of 4 lines')
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block = GroupCompressBlock.from_bytes(block_bytes)
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for start in xrange(0, len(header_lines), 4):
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key = tuple(header_lines[start].split('\x00'))
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parents_line = header_lines[start+1]
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if parents_line == 'None:':
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parents = tuple([tuple(segment.split('\x00'))
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for segment in parents_line.split('\t')
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start_offset = int(header_lines[start+2])
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end_offset = int(header_lines[start+3])
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result.add_factory(key, parents, start_offset, end_offset)
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def network_block_to_records(storage_kind, bytes, line_end):
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if storage_kind != 'groupcompress-block':
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raise ValueError('Unknown storage kind: %s' % (storage_kind,))
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manager = _LazyGroupContentManager.from_bytes(bytes)
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return manager.get_record_stream()
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class _CommonGroupCompressor(object):
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"""Create a GroupCompressor."""
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self.labels_deltas = {}
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self._delta_index = None # Set by the children
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self._block = GroupCompressBlock()
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def compress(self, key, bytes, expected_sha, nostore_sha=None, soft=False):
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"""Compress lines with label key.
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:param key: A key tuple. It is stored in the output
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for identification of the text during decompression. If the last
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element is 'None' it is replaced with the sha1 of the text -
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:param bytes: The bytes to be compressed
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:param expected_sha: If non-None, the sha the lines are believed to
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have. During compression the sha is calculated; a mismatch will
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:param nostore_sha: If the computed sha1 sum matches, we will raise
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ExistingContent rather than adding the text.
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:param soft: Do a 'soft' compression. This means that we require larger
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ranges to match to be considered for a copy command.
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:return: The sha1 of lines, the start and end offsets in the delta, and
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the type ('fulltext' or 'delta').
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:seealso VersionedFiles.add_lines:
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if not bytes: # empty, like a dir entry, etc
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if nostore_sha == _null_sha1:
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raise errors.ExistingContent()
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return _null_sha1, 0, 0, 'fulltext'
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# we assume someone knew what they were doing when they passed it in
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if expected_sha is not None:
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sha1 = osutils.sha_string(bytes)
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if nostore_sha is not None:
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if sha1 == nostore_sha:
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raise errors.ExistingContent()
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key = key[:-1] + ('sha1:' + sha1,)
697
start, end, type = self._compress(key, bytes, len(bytes) / 2, soft)
698
return sha1, start, end, type
700
def _compress(self, key, bytes, max_delta_size, soft=False):
701
"""Compress lines with label key.
703
:param key: A key tuple. It is stored in the output for identification
704
of the text during decompression.
706
:param bytes: The bytes to be compressed
708
:param max_delta_size: The size above which we issue a fulltext instead
711
:param soft: Do a 'soft' compression. This means that we require larger
712
ranges to match to be considered for a copy command.
714
:return: The sha1 of lines, the start and end offsets in the delta, and
715
the type ('fulltext' or 'delta').
717
raise NotImplementedError(self._compress)
719
def extract(self, key):
720
"""Extract a key previously added to the compressor.
722
:param key: The key to extract.
723
:return: An iterable over bytes and the sha1.
725
(start_byte, start_chunk, end_byte, end_chunk) = self.labels_deltas[key]
726
delta_chunks = self.chunks[start_chunk:end_chunk]
727
stored_bytes = ''.join(delta_chunks)
728
if stored_bytes[0] == 'f':
729
fulltext_len, offset = decode_base128_int(stored_bytes[1:10])
730
data_len = fulltext_len + 1 + offset
731
if data_len != len(stored_bytes):
732
raise ValueError('Index claimed fulltext len, but stored bytes'
734
% (len(stored_bytes), data_len))
735
bytes = stored_bytes[offset + 1:]
737
# XXX: This is inefficient at best
738
source = ''.join(self.chunks[:start_chunk])
739
if stored_bytes[0] != 'd':
740
raise ValueError('Unknown content kind, bytes claim %s'
741
% (stored_bytes[0],))
742
delta_len, offset = decode_base128_int(stored_bytes[1:10])
743
data_len = delta_len + 1 + offset
744
if data_len != len(stored_bytes):
745
raise ValueError('Index claimed delta len, but stored bytes'
747
% (len(stored_bytes), data_len))
748
bytes = apply_delta(source, stored_bytes[offset + 1:])
749
bytes_sha1 = osutils.sha_string(bytes)
750
return bytes, bytes_sha1
753
"""Finish this group, creating a formatted stream.
755
After calling this, the compressor should no longer be used
757
# TODO: this causes us to 'bloat' to 2x the size of content in the
758
# group. This has an impact for 'commit' of large objects.
759
# One possibility is to use self._content_chunks, and be lazy and
760
# only fill out self._content as a full string when we actually
761
# need it. That would at least drop the peak memory consumption
762
# for 'commit' down to ~1x the size of the largest file, at a
763
# cost of increased complexity within this code. 2x is still <<
764
# 3x the size of the largest file, so we are doing ok.
765
content = ''.join(self.chunks)
767
self._delta_index = None
768
self._block.set_content(content)
772
"""Call this if you want to 'revoke' the last compression.
774
After this, the data structures will be rolled back, but you cannot do
777
self._delta_index = None
778
del self.chunks[self._last[0]:]
779
self.endpoint = self._last[1]
783
"""Return the overall compression ratio."""
784
return float(self.input_bytes) / float(self.endpoint)
787
class PythonGroupCompressor(_CommonGroupCompressor):
790
"""Create a GroupCompressor.
792
Used only if the pyrex version is not available.
794
super(PythonGroupCompressor, self).__init__()
795
self._delta_index = LinesDeltaIndex([])
796
# The actual content is managed by LinesDeltaIndex
797
self.chunks = self._delta_index.lines
799
def _compress(self, key, bytes, max_delta_size, soft=False):
800
"""see _CommonGroupCompressor._compress"""
801
input_len = len(bytes)
802
new_lines = osutils.split_lines(bytes)
803
out_lines, index_lines = self._delta_index.make_delta(
804
new_lines, bytes_length=input_len, soft=soft)
805
delta_length = sum(map(len, out_lines))
806
if delta_length > max_delta_size:
807
# The delta is longer than the fulltext, insert a fulltext
809
out_lines = ['f', encode_base128_int(input_len)]
810
out_lines.extend(new_lines)
811
index_lines = [False, False]
812
index_lines.extend([True] * len(new_lines))
814
# this is a worthy delta, output it
817
# Update the delta_length to include those two encoded integers
818
out_lines[1] = encode_base128_int(delta_length)
820
start = self.endpoint
821
chunk_start = len(self.chunks)
822
self._last = (chunk_start, self.endpoint)
823
self._delta_index.extend_lines(out_lines, index_lines)
824
self.endpoint = self._delta_index.endpoint
825
self.input_bytes += input_len
826
chunk_end = len(self.chunks)
827
self.labels_deltas[key] = (start, chunk_start,
828
self.endpoint, chunk_end)
829
return start, self.endpoint, type
832
class PyrexGroupCompressor(_CommonGroupCompressor):
833
"""Produce a serialised group of compressed texts.
835
It contains code very similar to SequenceMatcher because of having a similar
836
task. However some key differences apply:
837
- there is no junk, we want a minimal edit not a human readable diff.
838
- we don't filter very common lines (because we don't know where a good
839
range will start, and after the first text we want to be emitting minmal
841
- we chain the left side, not the right side
842
- we incrementally update the adjacency matrix as new lines are provided.
843
- we look for matches in all of the left side, so the routine which does
844
the analagous task of find_longest_match does not need to filter on the
849
super(PyrexGroupCompressor, self).__init__()
850
self._delta_index = DeltaIndex()
852
def _compress(self, key, bytes, max_delta_size, soft=False):
853
"""see _CommonGroupCompressor._compress"""
854
input_len = len(bytes)
855
# By having action/label/sha1/len, we can parse the group if the index
856
# was ever destroyed, we have the key in 'label', we know the final
857
# bytes are valid from sha1, and we know where to find the end of this
858
# record because of 'len'. (the delta record itself will store the
859
# total length for the expanded record)
860
# 'len: %d\n' costs approximately 1% increase in total data
861
# Having the labels at all costs us 9-10% increase, 38% increase for
862
# inventory pages, and 5.8% increase for text pages
863
# new_chunks = ['label:%s\nsha1:%s\n' % (label, sha1)]
864
if self._delta_index._source_offset != self.endpoint:
865
raise AssertionError('_source_offset != endpoint'
866
' somehow the DeltaIndex got out of sync with'
868
delta = self._delta_index.make_delta(bytes, max_delta_size)
871
enc_length = encode_base128_int(len(bytes))
872
len_mini_header = 1 + len(enc_length)
873
self._delta_index.add_source(bytes, len_mini_header)
874
new_chunks = ['f', enc_length, bytes]
877
enc_length = encode_base128_int(len(delta))
878
len_mini_header = 1 + len(enc_length)
879
new_chunks = ['d', enc_length, delta]
880
self._delta_index.add_delta_source(delta, len_mini_header)
882
start = self.endpoint
883
chunk_start = len(self.chunks)
884
# Now output these bytes
885
self._output_chunks(new_chunks)
886
self.input_bytes += input_len
887
chunk_end = len(self.chunks)
888
self.labels_deltas[key] = (start, chunk_start,
889
self.endpoint, chunk_end)
890
if not self._delta_index._source_offset == self.endpoint:
891
raise AssertionError('the delta index is out of sync'
892
'with the output lines %s != %s'
893
% (self._delta_index._source_offset, self.endpoint))
894
return start, self.endpoint, type
896
def _output_chunks(self, new_chunks):
897
"""Output some chunks.
899
:param new_chunks: The chunks to output.
901
self._last = (len(self.chunks), self.endpoint)
902
endpoint = self.endpoint
903
self.chunks.extend(new_chunks)
904
endpoint += sum(map(len, new_chunks))
905
self.endpoint = endpoint
908
def make_pack_factory(graph, delta, keylength):
909
"""Create a factory for creating a pack based groupcompress.
911
This is only functional enough to run interface tests, it doesn't try to
912
provide a full pack environment.
914
:param graph: Store a graph.
915
:param delta: Delta compress contents.
916
:param keylength: How long should keys be.
918
def factory(transport):
923
graph_index = BTreeBuilder(reference_lists=ref_length,
924
key_elements=keylength)
925
stream = transport.open_write_stream('newpack')
926
writer = pack.ContainerWriter(stream.write)
928
index = _GCGraphIndex(graph_index, lambda:True, parents=parents,
929
add_callback=graph_index.add_nodes)
930
access = knit._DirectPackAccess({})
931
access.set_writer(writer, graph_index, (transport, 'newpack'))
932
result = GroupCompressVersionedFiles(index, access, delta)
933
result.stream = stream
934
result.writer = writer
939
def cleanup_pack_group(versioned_files):
940
versioned_files.writer.end()
941
versioned_files.stream.close()
944
class GroupCompressVersionedFiles(VersionedFiles):
945
"""A group-compress based VersionedFiles implementation."""
947
def __init__(self, index, access, delta=True):
948
"""Create a GroupCompressVersionedFiles object.
950
:param index: The index object storing access and graph data.
951
:param access: The access object storing raw data.
952
:param delta: Whether to delta compress or just entropy compress.
955
self._access = access
957
self._unadded_refs = {}
958
self._group_cache = LRUSizeCache(max_size=50*1024*1024)
959
self._fallback_vfs = []
961
def add_lines(self, key, parents, lines, parent_texts=None,
962
left_matching_blocks=None, nostore_sha=None, random_id=False,
964
"""Add a text to the store.
966
:param key: The key tuple of the text to add.
967
:param parents: The parents key tuples of the text to add.
968
:param lines: A list of lines. Each line must be a bytestring. And all
969
of them except the last must be terminated with \n and contain no
970
other \n's. The last line may either contain no \n's or a single
971
terminating \n. If the lines list does meet this constraint the add
972
routine may error or may succeed - but you will be unable to read
973
the data back accurately. (Checking the lines have been split
974
correctly is expensive and extremely unlikely to catch bugs so it
975
is not done at runtime unless check_content is True.)
976
:param parent_texts: An optional dictionary containing the opaque
977
representations of some or all of the parents of version_id to
978
allow delta optimisations. VERY IMPORTANT: the texts must be those
979
returned by add_lines or data corruption can be caused.
980
:param left_matching_blocks: a hint about which areas are common
981
between the text and its left-hand-parent. The format is
982
the SequenceMatcher.get_matching_blocks format.
983
:param nostore_sha: Raise ExistingContent and do not add the lines to
984
the versioned file if the digest of the lines matches this.
985
:param random_id: If True a random id has been selected rather than
986
an id determined by some deterministic process such as a converter
987
from a foreign VCS. When True the backend may choose not to check
988
for uniqueness of the resulting key within the versioned file, so
989
this should only be done when the result is expected to be unique
991
:param check_content: If True, the lines supplied are verified to be
992
bytestrings that are correctly formed lines.
993
:return: The text sha1, the number of bytes in the text, and an opaque
994
representation of the inserted version which can be provided
995
back to future add_lines calls in the parent_texts dictionary.
997
self._index._check_write_ok()
998
self._check_add(key, lines, random_id, check_content)
1000
# The caller might pass None if there is no graph data, but kndx
1001
# indexes can't directly store that, so we give them
1002
# an empty tuple instead.
1004
# double handling for now. Make it work until then.
1005
length = sum(map(len, lines))
1006
record = ChunkedContentFactory(key, parents, None, lines)
1007
sha1 = list(self._insert_record_stream([record], random_id=random_id,
1008
nostore_sha=nostore_sha))[0]
1009
return sha1, length, None
1011
def add_fallback_versioned_files(self, a_versioned_files):
1012
"""Add a source of texts for texts not present in this knit.
1014
:param a_versioned_files: A VersionedFiles object.
1016
self._fallback_vfs.append(a_versioned_files)
1018
def annotate(self, key):
1019
"""See VersionedFiles.annotate."""
1021
parent_map = self.get_parent_map([key])
1023
raise errors.RevisionNotPresent(key, self)
1024
if parent_map[key] is not None:
1025
parent_map = dict((k, v) for k, v in graph.iter_ancestry([key])
1027
keys = parent_map.keys()
1030
parent_map = {key:()}
1031
# We used Graph(self) to load the parent_map, but now that we have it,
1032
# we can just query the parent map directly, so create a KnownGraph
1033
heads_provider = _mod_graph.KnownGraph(parent_map)
1035
reannotate = annotate.reannotate
1036
for record in self.get_record_stream(keys, 'topological', True):
1038
lines = osutils.chunks_to_lines(record.get_bytes_as('chunked'))
1039
parent_lines = [parent_cache[parent] for parent in parent_map[key]]
1040
parent_cache[key] = list(
1041
reannotate(parent_lines, lines, key, None, heads_provider))
1042
return parent_cache[key]
1044
def check(self, progress_bar=None):
1045
"""See VersionedFiles.check()."""
1047
for record in self.get_record_stream(keys, 'unordered', True):
1048
record.get_bytes_as('fulltext')
1050
def _check_add(self, key, lines, random_id, check_content):
1051
"""check that version_id and lines are safe to add."""
1052
version_id = key[-1]
1053
if version_id is not None:
1054
if osutils.contains_whitespace(version_id):
1055
raise errors.InvalidRevisionId(version_id, self)
1056
self.check_not_reserved_id(version_id)
1057
# TODO: If random_id==False and the key is already present, we should
1058
# probably check that the existing content is identical to what is
1059
# being inserted, and otherwise raise an exception. This would make
1060
# the bundle code simpler.
1062
self._check_lines_not_unicode(lines)
1063
self._check_lines_are_lines(lines)
1065
def get_parent_map(self, keys):
1066
"""Get a map of the graph parents of keys.
1068
:param keys: The keys to look up parents for.
1069
:return: A mapping from keys to parents. Absent keys are absent from
1072
return self._get_parent_map_with_sources(keys)[0]
1074
def _get_parent_map_with_sources(self, keys):
1075
"""Get a map of the parents of keys.
1077
:param keys: The keys to look up parents for.
1078
:return: A tuple. The first element is a mapping from keys to parents.
1079
Absent keys are absent from the mapping. The second element is a
1080
list with the locations each key was found in. The first element
1081
is the in-this-knit parents, the second the first fallback source,
1085
sources = [self._index] + self._fallback_vfs
1088
for source in sources:
1091
new_result = source.get_parent_map(missing)
1092
source_results.append(new_result)
1093
result.update(new_result)
1094
missing.difference_update(set(new_result))
1095
return result, source_results
1097
def _get_block(self, index_memo):
1098
read_memo = index_memo[0:3]
1101
block = self._group_cache[read_memo]
1104
zdata = self._access.get_raw_records([read_memo]).next()
1105
# decompress - whole thing - this is not a bug, as it
1106
# permits caching. We might want to store the partially
1107
# decompresed group and decompress object, so that recent
1108
# texts are not penalised by big groups.
1109
block = GroupCompressBlock.from_bytes(zdata)
1110
self._group_cache[read_memo] = block
1112
# print len(zdata), len(plain)
1113
# parse - requires split_lines, better to have byte offsets
1114
# here (but not by much - we only split the region for the
1115
# recipe, and we often want to end up with lines anyway.
1118
def get_missing_compression_parent_keys(self):
1119
"""Return the keys of missing compression parents.
1121
Missing compression parents occur when a record stream was missing
1122
basis texts, or a index was scanned that had missing basis texts.
1124
# GroupCompress cannot currently reference texts that are not in the
1125
# group, so this is valid for now
1128
def get_record_stream(self, keys, ordering, include_delta_closure):
1129
"""Get a stream of records for keys.
1131
:param keys: The keys to include.
1132
:param ordering: Either 'unordered' or 'topological'. A topologically
1133
sorted stream has compression parents strictly before their
1135
:param include_delta_closure: If True then the closure across any
1136
compression parents will be included (in the opaque data).
1137
:return: An iterator of ContentFactory objects, each of which is only
1138
valid until the iterator is advanced.
1140
# keys might be a generator
1141
orig_keys = list(keys)
1145
if (not self._index.has_graph
1146
and ordering in ('topological', 'groupcompress')):
1147
# Cannot topological order when no graph has been stored.
1148
# but we allow 'as-requested' or 'unordered'
1149
ordering = 'unordered'
1151
remaining_keys = keys
1154
keys = set(remaining_keys)
1155
for content_factory in self._get_remaining_record_stream(keys,
1156
orig_keys, ordering, include_delta_closure):
1157
remaining_keys.discard(content_factory.key)
1158
yield content_factory
1160
except errors.RetryWithNewPacks, e:
1161
self._access.reload_or_raise(e)
1163
def _find_from_fallback(self, missing):
1164
"""Find whatever keys you can from the fallbacks.
1166
:param missing: A set of missing keys. This set will be mutated as keys
1167
are found from a fallback_vfs
1168
:return: (parent_map, key_to_source_map, source_results)
1169
parent_map the overall key => parent_keys
1170
key_to_source_map a dict from {key: source}
1171
source_results a list of (source: keys)
1174
key_to_source_map = {}
1176
for source in self._fallback_vfs:
1179
source_parents = source.get_parent_map(missing)
1180
parent_map.update(source_parents)
1181
source_parents = list(source_parents)
1182
source_results.append((source, source_parents))
1183
key_to_source_map.update((key, source) for key in source_parents)
1184
missing.difference_update(source_parents)
1185
return parent_map, key_to_source_map, source_results
1187
def _get_ordered_source_keys(self, ordering, parent_map, key_to_source_map):
1188
"""Get the (source, [keys]) list.
1190
The returned objects should be in the order defined by 'ordering',
1191
which can weave between different sources.
1192
:param ordering: Must be one of 'topological' or 'groupcompress'
1193
:return: List of [(source, [keys])] tuples, such that all keys are in
1194
the defined order, regardless of source.
1196
if ordering == 'topological':
1197
present_keys = topo_sort(parent_map)
1199
# ordering == 'groupcompress'
1200
# XXX: This only optimizes for the target ordering. We may need
1201
# to balance that with the time it takes to extract
1202
# ordering, by somehow grouping based on
1203
# locations[key][0:3]
1204
present_keys = sort_gc_optimal(parent_map)
1205
# Now group by source:
1207
current_source = None
1208
for key in present_keys:
1209
source = key_to_source_map.get(key, self)
1210
if source is not current_source:
1211
source_keys.append((source, []))
1212
current_source = source
1213
source_keys[-1][1].append(key)
1216
def _get_as_requested_source_keys(self, orig_keys, locations, unadded_keys,
1219
current_source = None
1220
for key in orig_keys:
1221
if key in locations or key in unadded_keys:
1223
elif key in key_to_source_map:
1224
source = key_to_source_map[key]
1227
if source is not current_source:
1228
source_keys.append((source, []))
1229
current_source = source
1230
source_keys[-1][1].append(key)
1233
def _get_io_ordered_source_keys(self, locations, unadded_keys,
1236
# This is the group the bytes are stored in, followed by the
1237
# location in the group
1238
return locations[key][0]
1239
present_keys = sorted(locations.iterkeys(), key=get_group)
1240
# We don't have an ordering for keys in the in-memory object, but
1241
# lets process the in-memory ones first.
1242
present_keys = list(unadded_keys) + present_keys
1243
# Now grab all of the ones from other sources
1244
source_keys = [(self, present_keys)]
1245
source_keys.extend(source_result)
1248
def _get_remaining_record_stream(self, keys, orig_keys, ordering,
1249
include_delta_closure):
1250
"""Get a stream of records for keys.
1252
:param keys: The keys to include.
1253
:param ordering: one of 'unordered', 'topological', 'groupcompress' or
1255
:param include_delta_closure: If True then the closure across any
1256
compression parents will be included (in the opaque data).
1257
:return: An iterator of ContentFactory objects, each of which is only
1258
valid until the iterator is advanced.
1261
locations = self._index.get_build_details(keys)
1262
unadded_keys = set(self._unadded_refs).intersection(keys)
1263
missing = keys.difference(locations)
1264
missing.difference_update(unadded_keys)
1265
(fallback_parent_map, key_to_source_map,
1266
source_result) = self._find_from_fallback(missing)
1267
if ordering in ('topological', 'groupcompress'):
1268
# would be better to not globally sort initially but instead
1269
# start with one key, recurse to its oldest parent, then grab
1270
# everything in the same group, etc.
1271
parent_map = dict((key, details[2]) for key, details in
1272
locations.iteritems())
1273
for key in unadded_keys:
1274
parent_map[key] = self._unadded_refs[key]
1275
parent_map.update(fallback_parent_map)
1276
source_keys = self._get_ordered_source_keys(ordering, parent_map,
1278
elif ordering == 'as-requested':
1279
source_keys = self._get_as_requested_source_keys(orig_keys,
1280
locations, unadded_keys, key_to_source_map)
1282
# We want to yield the keys in a semi-optimal (read-wise) ordering.
1283
# Otherwise we thrash the _group_cache and destroy performance
1284
source_keys = self._get_io_ordered_source_keys(locations,
1285
unadded_keys, source_result)
1287
yield AbsentContentFactory(key)
1289
last_read_memo = None
1290
# TODO: This works fairly well at batching up existing groups into a
1291
# streamable format, and possibly allowing for taking one big
1292
# group and splitting it when it isn't fully utilized.
1293
# However, it doesn't allow us to find under-utilized groups and
1294
# combine them into a bigger group on the fly.
1295
# (Consider the issue with how chk_map inserts texts
1296
# one-at-a-time.) This could be done at insert_record_stream()
1297
# time, but it probably would decrease the number of
1298
# bytes-on-the-wire for fetch.
1299
for source, keys in source_keys:
1302
if key in self._unadded_refs:
1303
if manager is not None:
1304
for factory in manager.get_record_stream():
1306
last_read_memo = manager = None
1307
bytes, sha1 = self._compressor.extract(key)
1308
parents = self._unadded_refs[key]
1309
yield FulltextContentFactory(key, parents, sha1, bytes)
1311
index_memo, _, parents, (method, _) = locations[key]
1312
read_memo = index_memo[0:3]
1313
if last_read_memo != read_memo:
1314
# We are starting a new block. If we have a
1315
# manager, we have found everything that fits for
1316
# now, so yield records
1317
if manager is not None:
1318
for factory in manager.get_record_stream():
1320
# Now start a new manager
1321
block = self._get_block(index_memo)
1322
manager = _LazyGroupContentManager(block)
1323
last_read_memo = read_memo
1324
start, end = index_memo[3:5]
1325
manager.add_factory(key, parents, start, end)
1327
if manager is not None:
1328
for factory in manager.get_record_stream():
1330
last_read_memo = manager = None
1331
for record in source.get_record_stream(keys, ordering,
1332
include_delta_closure):
1334
if manager is not None:
1335
for factory in manager.get_record_stream():
1338
def get_sha1s(self, keys):
1339
"""See VersionedFiles.get_sha1s()."""
1341
for record in self.get_record_stream(keys, 'unordered', True):
1342
if record.sha1 != None:
1343
result[record.key] = record.sha1
1345
if record.storage_kind != 'absent':
1346
result[record.key] = osutils.sha_string(
1347
record.get_bytes_as('fulltext'))
1350
def insert_record_stream(self, stream):
1351
"""Insert a record stream into this container.
1353
:param stream: A stream of records to insert.
1355
:seealso VersionedFiles.get_record_stream:
1357
# XXX: Setting random_id=True makes
1358
# test_insert_record_stream_existing_keys fail for groupcompress and
1359
# groupcompress-nograph, this needs to be revisited while addressing
1360
# 'bzr branch' performance issues.
1361
for _ in self._insert_record_stream(stream, random_id=False):
1364
def _insert_record_stream(self, stream, random_id=False, nostore_sha=None,
1366
"""Internal core to insert a record stream into this container.
1368
This helper function has a different interface than insert_record_stream
1369
to allow add_lines to be minimal, but still return the needed data.
1371
:param stream: A stream of records to insert.
1372
:param nostore_sha: If the sha1 of a given text matches nostore_sha,
1373
raise ExistingContent, rather than committing the new text.
1374
:param reuse_blocks: If the source is streaming from
1375
groupcompress-blocks, just insert the blocks as-is, rather than
1376
expanding the texts and inserting again.
1377
:return: An iterator over the sha1 of the inserted records.
1378
:seealso insert_record_stream:
1382
def get_adapter(adapter_key):
1384
return adapters[adapter_key]
1386
adapter_factory = adapter_registry.get(adapter_key)
1387
adapter = adapter_factory(self)
1388
adapters[adapter_key] = adapter
1390
# This will go up to fulltexts for gc to gc fetching, which isn't
1392
self._compressor = GroupCompressor()
1393
self._unadded_refs = {}
1396
bytes = self._compressor.flush().to_bytes()
1397
index, start, length = self._access.add_raw_records(
1398
[(None, len(bytes))], bytes)[0]
1400
for key, reads, refs in keys_to_add:
1401
nodes.append((key, "%d %d %s" % (start, length, reads), refs))
1402
self._index.add_records(nodes, random_id=random_id)
1403
self._unadded_refs = {}
1405
self._compressor = GroupCompressor()
1408
max_fulltext_len = 0
1409
max_fulltext_prefix = None
1410
insert_manager = None
1413
# XXX: TODO: remove this, it is just for safety checking for now
1414
inserted_keys = set()
1415
for record in stream:
1416
# Raise an error when a record is missing.
1417
if record.storage_kind == 'absent':
1418
raise errors.RevisionNotPresent(record.key, self)
1420
if record.key in inserted_keys:
1421
trace.note('Insert claimed random_id=True,'
1422
' but then inserted %r two times', record.key)
1424
inserted_keys.add(record.key)
1426
# If the reuse_blocks flag is set, check to see if we can just
1427
# copy a groupcompress block as-is.
1428
if record.storage_kind == 'groupcompress-block':
1429
# Insert the raw block into the target repo
1430
insert_manager = record._manager
1431
insert_manager._check_rebuild_block()
1432
bytes = record._manager._block.to_bytes()
1433
_, start, length = self._access.add_raw_records(
1434
[(None, len(bytes))], bytes)[0]
1437
block_length = length
1438
if record.storage_kind in ('groupcompress-block',
1439
'groupcompress-block-ref'):
1440
if insert_manager is None:
1441
raise AssertionError('No insert_manager set')
1442
value = "%d %d %d %d" % (block_start, block_length,
1443
record._start, record._end)
1444
nodes = [(record.key, value, (record.parents,))]
1445
# TODO: Consider buffering up many nodes to be added, not
1446
# sure how much overhead this has, but we're seeing
1447
# ~23s / 120s in add_records calls
1448
self._index.add_records(nodes, random_id=random_id)
1451
bytes = record.get_bytes_as('fulltext')
1452
except errors.UnavailableRepresentation:
1453
adapter_key = record.storage_kind, 'fulltext'
1454
adapter = get_adapter(adapter_key)
1455
bytes = adapter.get_bytes(record)
1456
if len(record.key) > 1:
1457
prefix = record.key[0]
1458
soft = (prefix == last_prefix)
1462
if max_fulltext_len < len(bytes):
1463
max_fulltext_len = len(bytes)
1464
max_fulltext_prefix = prefix
1465
(found_sha1, start_point, end_point,
1466
type) = self._compressor.compress(record.key,
1467
bytes, record.sha1, soft=soft,
1468
nostore_sha=nostore_sha)
1469
# delta_ratio = float(len(bytes)) / (end_point - start_point)
1470
# Check if we want to continue to include that text
1471
if (prefix == max_fulltext_prefix
1472
and end_point < 2 * max_fulltext_len):
1473
# As long as we are on the same file_id, we will fill at least
1474
# 2 * max_fulltext_len
1475
start_new_block = False
1476
elif end_point > 4*1024*1024:
1477
start_new_block = True
1478
elif (prefix is not None and prefix != last_prefix
1479
and end_point > 2*1024*1024):
1480
start_new_block = True
1482
start_new_block = False
1483
last_prefix = prefix
1485
self._compressor.pop_last()
1487
max_fulltext_len = len(bytes)
1488
(found_sha1, start_point, end_point,
1489
type) = self._compressor.compress(record.key, bytes,
1491
if record.key[-1] is None:
1492
key = record.key[:-1] + ('sha1:' + found_sha1,)
1495
self._unadded_refs[key] = record.parents
1497
keys_to_add.append((key, '%d %d' % (start_point, end_point),
1499
if len(keys_to_add):
1501
self._compressor = None
1503
def iter_lines_added_or_present_in_keys(self, keys, pb=None):
1504
"""Iterate over the lines in the versioned files from keys.
1506
This may return lines from other keys. Each item the returned
1507
iterator yields is a tuple of a line and a text version that that line
1508
is present in (not introduced in).
1510
Ordering of results is in whatever order is most suitable for the
1511
underlying storage format.
1513
If a progress bar is supplied, it may be used to indicate progress.
1514
The caller is responsible for cleaning up progress bars (because this
1518
* Lines are normalised by the underlying store: they will all have \n
1520
* Lines are returned in arbitrary order.
1522
:return: An iterator over (line, key).
1525
pb = progress.DummyProgress()
1528
# we don't care about inclusions, the caller cares.
1529
# but we need to setup a list of records to visit.
1530
# we need key, position, length
1531
for key_idx, record in enumerate(self.get_record_stream(keys,
1532
'unordered', True)):
1533
# XXX: todo - optimise to use less than full texts.
1535
pb.update('Walking content', key_idx, total)
1536
if record.storage_kind == 'absent':
1537
raise errors.RevisionNotPresent(key, self)
1538
lines = osutils.split_lines(record.get_bytes_as('fulltext'))
1541
pb.update('Walking content', total, total)
1544
"""See VersionedFiles.keys."""
1545
if 'evil' in debug.debug_flags:
1546
trace.mutter_callsite(2, "keys scales with size of history")
1547
sources = [self._index] + self._fallback_vfs
1549
for source in sources:
1550
result.update(source.keys())
1554
class _GCGraphIndex(object):
1555
"""Mapper from GroupCompressVersionedFiles needs into GraphIndex storage."""
1557
def __init__(self, graph_index, is_locked, parents=True,
1558
add_callback=None, track_external_parent_refs=False):
1559
"""Construct a _GCGraphIndex on a graph_index.
1561
:param graph_index: An implementation of bzrlib.index.GraphIndex.
1562
:param is_locked: A callback, returns True if the index is locked and
1564
:param parents: If True, record knits parents, if not do not record
1566
:param add_callback: If not None, allow additions to the index and call
1567
this callback with a list of added GraphIndex nodes:
1568
[(node, value, node_refs), ...]
1569
:param track_external_parent_refs: As keys are added, keep track of the
1570
keys they reference, so that we can query get_missing_parents(),
1573
self._add_callback = add_callback
1574
self._graph_index = graph_index
1575
self._parents = parents
1576
self.has_graph = parents
1577
self._is_locked = is_locked
1578
if track_external_parent_refs:
1579
self._key_dependencies = knit._KeyRefs()
1581
self._key_dependencies = None
1583
def add_records(self, records, random_id=False):
1584
"""Add multiple records to the index.
1586
This function does not insert data into the Immutable GraphIndex
1587
backing the KnitGraphIndex, instead it prepares data for insertion by
1588
the caller and checks that it is safe to insert then calls
1589
self._add_callback with the prepared GraphIndex nodes.
1591
:param records: a list of tuples:
1592
(key, options, access_memo, parents).
1593
:param random_id: If True the ids being added were randomly generated
1594
and no check for existence will be performed.
1596
if not self._add_callback:
1597
raise errors.ReadOnlyError(self)
1598
# we hope there are no repositories with inconsistent parentage
1603
for (key, value, refs) in records:
1604
if not self._parents:
1608
raise KnitCorrupt(self,
1609
"attempt to add node with parents "
1610
"in parentless index.")
1613
keys[key] = (value, refs)
1616
present_nodes = self._get_entries(keys)
1617
for (index, key, value, node_refs) in present_nodes:
1618
if node_refs != keys[key][1]:
1619
raise errors.KnitCorrupt(self, "inconsistent details in add_records"
1620
": %s %s" % ((value, node_refs), keys[key]))
1626
for key, (value, node_refs) in keys.iteritems():
1627
result.append((key, value, node_refs))
1629
for key, (value, node_refs) in keys.iteritems():
1630
result.append((key, value))
1632
key_dependencies = self._key_dependencies
1633
if key_dependencies is not None and self._parents:
1634
for key, value, refs in records:
1636
key_dependencies.add_references(key, parents)
1637
self._add_callback(records)
1639
def _check_read(self):
1640
"""Raise an exception if reads are not permitted."""
1641
if not self._is_locked():
1642
raise errors.ObjectNotLocked(self)
1644
def _check_write_ok(self):
1645
"""Raise an exception if writes are not permitted."""
1646
if not self._is_locked():
1647
raise errors.ObjectNotLocked(self)
1649
def _get_entries(self, keys, check_present=False):
1650
"""Get the entries for keys.
1652
Note: Callers are responsible for checking that the index is locked
1653
before calling this method.
1655
:param keys: An iterable of index key tuples.
1660
for node in self._graph_index.iter_entries(keys):
1662
found_keys.add(node[1])
1664
# adapt parentless index to the rest of the code.
1665
for node in self._graph_index.iter_entries(keys):
1666
yield node[0], node[1], node[2], ()
1667
found_keys.add(node[1])
1669
missing_keys = keys.difference(found_keys)
1671
raise RevisionNotPresent(missing_keys.pop(), self)
1673
def get_parent_map(self, keys):
1674
"""Get a map of the parents of keys.
1676
:param keys: The keys to look up parents for.
1677
:return: A mapping from keys to parents. Absent keys are absent from
1681
nodes = self._get_entries(keys)
1685
result[node[1]] = node[3][0]
1688
result[node[1]] = None
1691
def get_missing_parents(self):
1692
"""Return the keys of missing parents."""
1693
# Copied from _KnitGraphIndex.get_missing_parents
1694
# We may have false positives, so filter those out.
1695
self._key_dependencies.add_keys(
1696
self.get_parent_map(self._key_dependencies.get_unsatisfied_refs()))
1697
return frozenset(self._key_dependencies.get_unsatisfied_refs())
1699
def get_build_details(self, keys):
1700
"""Get the various build details for keys.
1702
Ghosts are omitted from the result.
1704
:param keys: An iterable of keys.
1705
:return: A dict of key:
1706
(index_memo, compression_parent, parents, record_details).
1708
opaque structure to pass to read_records to extract the raw
1711
Content that this record is built upon, may be None
1713
Logical parents of this node
1715
extra information about the content which needs to be passed to
1716
Factory.parse_record
1720
entries = self._get_entries(keys)
1721
for entry in entries:
1723
if not self._parents:
1726
parents = entry[3][0]
1728
result[key] = (self._node_to_position(entry),
1729
None, parents, (method, None))
1733
"""Get all the keys in the collection.
1735
The keys are not ordered.
1738
return [node[1] for node in self._graph_index.iter_all_entries()]
1740
def _node_to_position(self, node):
1741
"""Convert an index value to position details."""
1742
bits = node[2].split(' ')
1743
# It would be nice not to read the entire gzip.
1744
start = int(bits[0])
1746
basis_end = int(bits[2])
1747
delta_end = int(bits[3])
1748
return node[0], start, stop, basis_end, delta_end
1750
def scan_unvalidated_index(self, graph_index):
1751
"""Inform this _GCGraphIndex that there is an unvalidated index.
1753
This allows this _GCGraphIndex to keep track of any missing
1754
compression parents we may want to have filled in to make those
1757
:param graph_index: A GraphIndex
1759
if self._key_dependencies is not None:
1760
# Add parent refs from graph_index (and discard parent refs that
1761
# the graph_index has).
1762
add_refs = self._key_dependencies.add_references
1763
for node in graph_index.iter_all_entries():
1764
add_refs(node[1], node[3][0])
1768
from bzrlib._groupcompress_py import (
1770
apply_delta_to_source,
1773
decode_copy_instruction,
1777
from bzrlib._groupcompress_pyx import (
1779
apply_delta_to_source,
1784
GroupCompressor = PyrexGroupCompressor
1786
GroupCompressor = PythonGroupCompressor
added
removed
bzrlib/groupcompress.py
