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# Copyright (C) 2008, 2009, 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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"""Core compression logic for compressing streams of related files."""
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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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# Minimum number of uncompressed bytes to try fetch at once when retrieving
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# groupcompress blocks.
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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 key, value in parent_map.iteritems():
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if isinstance(key, str) or len(key) == 1:
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per_prefix_map[prefix][key] = value
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per_prefix_map[prefix] = {key: value}
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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_chunks = 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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self._content_chunks = 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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if self._content_length is None:
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raise AssertionError('self._content_length should never be None')
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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._content_chunks is not None:
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self._content = ''.join(self._content_chunks)
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self._content_chunks = None
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if self._content is None:
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# We join self._z_content_chunks here, because if we are
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# decompressing, then it is *very* likely that we have a single
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if self._z_content_chunks is None:
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raise AssertionError('No content to decompress')
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z_content = ''.join(self._z_content_chunks)
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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(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 * 4 > self._content_length * 3:
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# If we are requesting more that 3/4ths of the content,
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# just extract the whole thing in a single pass
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num_bytes = self._content_length
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self._content = zlib.decompress(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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z_content, num_bytes + _ZLIB_DECOMP_WINDOW)
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if not self._z_content_decompressor.unconsumed_tail:
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self._z_content_decompressor = None
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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 len(self._content) >= num_bytes:
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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 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_chunks = (bytes[pos:],)
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def _z_content(self):
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"""Return z_content_chunks as a simple string.
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Meant only to be used by the test suite.
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if self._z_content_chunks is not None:
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return ''.join(self._z_content_chunks)
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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_chunked_content(self, content_chunks, length):
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"""Set the content of this block to the given chunks."""
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# If we have lots of short lines, it is may be more efficient to join
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# the content ahead of time. If the content is <10MiB, we don't really
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# care about the extra memory consumption, so we can just pack it and
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# be done. However, timing showed 18s => 17.9s for repacking 1k revs of
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# mysql, which is below the noise margin
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self._content_length = length
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self._content_chunks = content_chunks
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self._z_content_chunks = None
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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_chunks = None
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def _create_z_content_using_lzma(self):
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if self._content_chunks is not None:
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self._content = ''.join(self._content_chunks)
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self._content_chunks = None
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if self._content is None:
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raise AssertionError('Nothing to compress')
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z_content = pylzma.compress(self._content)
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self._z_content_chunks = (z_content,)
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self._z_content_length = len(z_content)
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def _create_z_content_from_chunks(self, chunks):
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compressor = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION)
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# Peak in this point is 1 fulltext, 1 compressed text, + zlib overhead
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# (measured peak is maybe 30MB over the above...)
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compressed_chunks = map(compressor.compress, chunks)
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compressed_chunks.append(compressor.flush())
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# Ignore empty chunks
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self._z_content_chunks = [c for c in compressed_chunks if c]
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self._z_content_length = sum(map(len, self._z_content_chunks))
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def _create_z_content(self):
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if self._z_content_chunks is not None:
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self._create_z_content_using_lzma()
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if self._content_chunks is not None:
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chunks = self._content_chunks
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chunks = (self._content,)
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self._create_z_content_from_chunks(chunks)
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"""Create the byte stream as a series of 'chunks'"""
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self._create_z_content()
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header = self.GCB_LZ_HEADER
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header = self.GCB_HEADER
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chunks = ['%s%d\n%d\n'
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% (header, self._z_content_length, self._content_length),
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chunks.extend(self._z_content_chunks)
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total_len = sum(map(len, chunks))
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return total_len, chunks
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"""Encode the information into a byte stream."""
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total_len, chunks = self.to_chunks()
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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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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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_max_cut_fraction = 0.75 # We allow a block to be trimmed to 75% of
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# current size, and still be considered
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_full_block_size = 4*1024*1024
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_full_mixed_block_size = 2*1024*1024
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_full_enough_block_size = 3*1024*1024 # size at which we won't repack
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_full_enough_mixed_block_size = 2*768*1024 # 1.5MB
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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_action(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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if last_byte_used < factory._end:
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last_byte_used = factory._end
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# If we are using more than half of the bytes from the block, we have
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# nothing else to check
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if total_bytes_used * 2 >= self._block._content_length:
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return None, last_byte_used, total_bytes_used
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# We are using less than 50% of the content. Is the content we are
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# using at the beginning of the block? If so, we can just trim the
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# tail, rather than rebuilding from scratch.
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if total_bytes_used * 2 > last_byte_used:
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return 'trim', last_byte_used, total_bytes_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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return 'rebuild', last_byte_used, total_bytes_used
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def check_is_well_utilized(self):
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"""Is the current block considered 'well utilized'?
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This heuristic asks if the current block considers itself to be a fully
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developed group, rather than just a loose collection of data.
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if len(self._factories) == 1:
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# A block of length 1 could be improved by combining with other
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# groups - don't look deeper. Even larger than max size groups
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# could compress well with adjacent versions of the same thing.
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action, last_byte_used, total_bytes_used = self._check_rebuild_action()
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block_size = self._block._content_length
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if total_bytes_used < block_size * self._max_cut_fraction:
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# This block wants to trim itself small enough that we want to
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# consider it under-utilized.
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# TODO: This code is meant to be the twin of _insert_record_stream's
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# 'start_new_block' logic. It would probably be better to factor
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# out that logic into a shared location, so that it stays
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# We currently assume a block is properly utilized whenever it is >75%
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# of the size of a 'full' block. In normal operation, a block is
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# considered full when it hits 4MB of same-file content. So any block
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# >3MB is 'full enough'.
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# The only time this isn't true is when a given block has large-object
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# content. (a single file >4MB, etc.)
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# Under these circumstances, we allow a block to grow to
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# 2 x largest_content. Which means that if a given block had a large
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# object, it may actually be under-utilized. However, given that this
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# is 'pack-on-the-fly' it is probably reasonable to not repack large
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# content blobs on-the-fly. Note that because we return False for all
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# 1-item blobs, we will repack them; we may wish to reevaluate our
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# treatment of large object blobs in the future.
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if block_size >= self._full_enough_block_size:
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# If a block is <3MB, it still may be considered 'full' if it contains
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# mixed content. The current rule is 2MB of mixed content is considered
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# full. So check to see if this block contains mixed content, and
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# set the threshold appropriately.
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for factory in self._factories:
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prefix = factory.key[:-1]
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if common_prefix is None:
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common_prefix = prefix
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elif prefix != common_prefix:
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# Mixed content, check the size appropriately
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if block_size >= self._full_enough_mixed_block_size:
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# The content failed both the mixed check and the single-content check
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# so obviously it is not fully utilized
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# TODO: there is one other constraint that isn't being checked
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# namely, that the entries in the block are in the appropriate
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# order. For example, you could insert the entries in exactly
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# reverse groupcompress order, and we would think that is ok.
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# (all the right objects are in one group, and it is fully
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# utilized, etc.) For now, we assume that case is rare,
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# especially since we should always fetch in 'groupcompress'
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def _check_rebuild_block(self):
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action, last_byte_used, total_bytes_used = self._check_rebuild_action()
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self._trim_block(last_byte_used)
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elif action == 'rebuild':
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self._rebuild_block()
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raise ValueError('unknown rebuild action: %r' % (action,))
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def _wire_bytes(self):
669
"""Return a byte stream suitable for transmitting over the wire."""
670
self._check_rebuild_block()
671
# The outer block starts with:
672
# 'groupcompress-block\n'
673
# <length of compressed key info>\n
674
# <length of uncompressed info>\n
675
# <length of gc block>\n
678
lines = ['groupcompress-block\n']
679
# The minimal info we need is the key, the start offset, and the
680
# parents. The length and type are encoded in the record itself.
681
# However, passing in the other bits makes it easier. The list of
682
# keys, and the start offset, the length
684
# 1 line with parents, '' for ()
685
# 1 line for start offset
686
# 1 line for end byte
688
for factory in self._factories:
689
key_bytes = '\x00'.join(factory.key)
690
parents = factory.parents
692
parent_bytes = 'None:'
694
parent_bytes = '\t'.join('\x00'.join(key) for key in parents)
695
record_header = '%s\n%s\n%d\n%d\n' % (
696
key_bytes, parent_bytes, factory._start, factory._end)
697
header_lines.append(record_header)
698
# TODO: Can we break the refcycle at this point and set
699
# factory._manager = None?
700
header_bytes = ''.join(header_lines)
702
header_bytes_len = len(header_bytes)
703
z_header_bytes = zlib.compress(header_bytes)
705
z_header_bytes_len = len(z_header_bytes)
706
block_bytes_len, block_chunks = self._block.to_chunks()
707
lines.append('%d\n%d\n%d\n' % (z_header_bytes_len, header_bytes_len,
709
lines.append(z_header_bytes)
710
lines.extend(block_chunks)
711
del z_header_bytes, block_chunks
712
# TODO: This is a point where we will double the memory consumption. To
713
# avoid this, we probably have to switch to a 'chunked' api
714
return ''.join(lines)
717
def from_bytes(cls, bytes):
718
# TODO: This does extra string copying, probably better to do it a
719
# different way. At a minimum this creates 2 copies of the
721
(storage_kind, z_header_len, header_len,
722
block_len, rest) = bytes.split('\n', 4)
724
if storage_kind != 'groupcompress-block':
725
raise ValueError('Unknown storage kind: %s' % (storage_kind,))
726
z_header_len = int(z_header_len)
727
if len(rest) < z_header_len:
728
raise ValueError('Compressed header len shorter than all bytes')
729
z_header = rest[:z_header_len]
730
header_len = int(header_len)
731
header = zlib.decompress(z_header)
732
if len(header) != header_len:
733
raise ValueError('invalid length for decompressed bytes')
735
block_len = int(block_len)
736
if len(rest) != z_header_len + block_len:
737
raise ValueError('Invalid length for block')
738
block_bytes = rest[z_header_len:]
740
# So now we have a valid GCB, we just need to parse the factories that
742
header_lines = header.split('\n')
744
last = header_lines.pop()
746
raise ValueError('header lines did not end with a trailing'
748
if len(header_lines) % 4 != 0:
749
raise ValueError('The header was not an even multiple of 4 lines')
750
block = GroupCompressBlock.from_bytes(block_bytes)
753
for start in xrange(0, len(header_lines), 4):
755
key = tuple(header_lines[start].split('\x00'))
756
parents_line = header_lines[start+1]
757
if parents_line == 'None:':
760
parents = tuple([tuple(segment.split('\x00'))
761
for segment in parents_line.split('\t')
763
start_offset = int(header_lines[start+2])
764
end_offset = int(header_lines[start+3])
765
result.add_factory(key, parents, start_offset, end_offset)
769
def network_block_to_records(storage_kind, bytes, line_end):
770
if storage_kind != 'groupcompress-block':
771
raise ValueError('Unknown storage kind: %s' % (storage_kind,))
772
manager = _LazyGroupContentManager.from_bytes(bytes)
773
return manager.get_record_stream()
776
class _CommonGroupCompressor(object):
779
"""Create a GroupCompressor."""
784
self.labels_deltas = {}
785
self._delta_index = None # Set by the children
786
self._block = GroupCompressBlock()
788
def compress(self, key, bytes, expected_sha, nostore_sha=None, soft=False):
789
"""Compress lines with label key.
791
:param key: A key tuple. It is stored in the output
792
for identification of the text during decompression. If the last
793
element is 'None' it is replaced with the sha1 of the text -
795
:param bytes: The bytes to be compressed
796
:param expected_sha: If non-None, the sha the lines are believed to
797
have. During compression the sha is calculated; a mismatch will
799
:param nostore_sha: If the computed sha1 sum matches, we will raise
800
ExistingContent rather than adding the text.
801
:param soft: Do a 'soft' compression. This means that we require larger
802
ranges to match to be considered for a copy command.
804
:return: The sha1 of lines, the start and end offsets in the delta, and
805
the type ('fulltext' or 'delta').
807
:seealso VersionedFiles.add_lines:
809
if not bytes: # empty, like a dir entry, etc
810
if nostore_sha == _null_sha1:
811
raise errors.ExistingContent()
812
return _null_sha1, 0, 0, 'fulltext'
813
# we assume someone knew what they were doing when they passed it in
814
if expected_sha is not None:
817
sha1 = osutils.sha_string(bytes)
818
if nostore_sha is not None:
819
if sha1 == nostore_sha:
820
raise errors.ExistingContent()
822
key = key[:-1] + ('sha1:' + sha1,)
824
start, end, type = self._compress(key, bytes, len(bytes) / 2, soft)
825
return sha1, start, end, type
827
def _compress(self, key, bytes, max_delta_size, soft=False):
828
"""Compress lines with label key.
830
:param key: A key tuple. It is stored in the output for identification
831
of the text during decompression.
833
:param bytes: The bytes to be compressed
835
:param max_delta_size: The size above which we issue a fulltext instead
838
:param soft: Do a 'soft' compression. This means that we require larger
839
ranges to match to be considered for a copy command.
841
:return: The sha1 of lines, the start and end offsets in the delta, and
842
the type ('fulltext' or 'delta').
844
raise NotImplementedError(self._compress)
846
def extract(self, key):
847
"""Extract a key previously added to the compressor.
849
:param key: The key to extract.
850
:return: An iterable over bytes and the sha1.
852
(start_byte, start_chunk, end_byte, end_chunk) = self.labels_deltas[key]
853
delta_chunks = self.chunks[start_chunk:end_chunk]
854
stored_bytes = ''.join(delta_chunks)
855
if stored_bytes[0] == 'f':
856
fulltext_len, offset = decode_base128_int(stored_bytes[1:10])
857
data_len = fulltext_len + 1 + offset
858
if data_len != len(stored_bytes):
859
raise ValueError('Index claimed fulltext len, but stored bytes'
861
% (len(stored_bytes), data_len))
862
bytes = stored_bytes[offset + 1:]
864
# XXX: This is inefficient at best
865
source = ''.join(self.chunks[:start_chunk])
866
if stored_bytes[0] != 'd':
867
raise ValueError('Unknown content kind, bytes claim %s'
868
% (stored_bytes[0],))
869
delta_len, offset = decode_base128_int(stored_bytes[1:10])
870
data_len = delta_len + 1 + offset
871
if data_len != len(stored_bytes):
872
raise ValueError('Index claimed delta len, but stored bytes'
874
% (len(stored_bytes), data_len))
875
bytes = apply_delta(source, stored_bytes[offset + 1:])
876
bytes_sha1 = osutils.sha_string(bytes)
877
return bytes, bytes_sha1
880
"""Finish this group, creating a formatted stream.
882
After calling this, the compressor should no longer be used
884
self._block.set_chunked_content(self.chunks, self.endpoint)
886
self._delta_index = None
890
"""Call this if you want to 'revoke' the last compression.
892
After this, the data structures will be rolled back, but you cannot do
895
self._delta_index = None
896
del self.chunks[self._last[0]:]
897
self.endpoint = self._last[1]
901
"""Return the overall compression ratio."""
902
return float(self.input_bytes) / float(self.endpoint)
905
class PythonGroupCompressor(_CommonGroupCompressor):
908
"""Create a GroupCompressor.
910
Used only if the pyrex version is not available.
912
super(PythonGroupCompressor, self).__init__()
913
self._delta_index = LinesDeltaIndex([])
914
# The actual content is managed by LinesDeltaIndex
915
self.chunks = self._delta_index.lines
917
def _compress(self, key, bytes, max_delta_size, soft=False):
918
"""see _CommonGroupCompressor._compress"""
919
input_len = len(bytes)
920
new_lines = osutils.split_lines(bytes)
921
out_lines, index_lines = self._delta_index.make_delta(
922
new_lines, bytes_length=input_len, soft=soft)
923
delta_length = sum(map(len, out_lines))
924
if delta_length > max_delta_size:
925
# The delta is longer than the fulltext, insert a fulltext
927
out_lines = ['f', encode_base128_int(input_len)]
928
out_lines.extend(new_lines)
929
index_lines = [False, False]
930
index_lines.extend([True] * len(new_lines))
932
# this is a worthy delta, output it
935
# Update the delta_length to include those two encoded integers
936
out_lines[1] = encode_base128_int(delta_length)
938
start = self.endpoint
939
chunk_start = len(self.chunks)
940
self._last = (chunk_start, self.endpoint)
941
self._delta_index.extend_lines(out_lines, index_lines)
942
self.endpoint = self._delta_index.endpoint
943
self.input_bytes += input_len
944
chunk_end = len(self.chunks)
945
self.labels_deltas[key] = (start, chunk_start,
946
self.endpoint, chunk_end)
947
return start, self.endpoint, type
950
class PyrexGroupCompressor(_CommonGroupCompressor):
951
"""Produce a serialised group of compressed texts.
953
It contains code very similar to SequenceMatcher because of having a similar
954
task. However some key differences apply:
955
- there is no junk, we want a minimal edit not a human readable diff.
956
- we don't filter very common lines (because we don't know where a good
957
range will start, and after the first text we want to be emitting minmal
959
- we chain the left side, not the right side
960
- we incrementally update the adjacency matrix as new lines are provided.
961
- we look for matches in all of the left side, so the routine which does
962
the analagous task of find_longest_match does not need to filter on the
967
super(PyrexGroupCompressor, self).__init__()
968
self._delta_index = DeltaIndex()
970
def _compress(self, key, bytes, max_delta_size, soft=False):
971
"""see _CommonGroupCompressor._compress"""
972
input_len = len(bytes)
973
# By having action/label/sha1/len, we can parse the group if the index
974
# was ever destroyed, we have the key in 'label', we know the final
975
# bytes are valid from sha1, and we know where to find the end of this
976
# record because of 'len'. (the delta record itself will store the
977
# total length for the expanded record)
978
# 'len: %d\n' costs approximately 1% increase in total data
979
# Having the labels at all costs us 9-10% increase, 38% increase for
980
# inventory pages, and 5.8% increase for text pages
981
# new_chunks = ['label:%s\nsha1:%s\n' % (label, sha1)]
982
if self._delta_index._source_offset != self.endpoint:
983
raise AssertionError('_source_offset != endpoint'
984
' somehow the DeltaIndex got out of sync with'
986
delta = self._delta_index.make_delta(bytes, max_delta_size)
989
enc_length = encode_base128_int(len(bytes))
990
len_mini_header = 1 + len(enc_length)
991
self._delta_index.add_source(bytes, len_mini_header)
992
new_chunks = ['f', enc_length, bytes]
995
enc_length = encode_base128_int(len(delta))
996
len_mini_header = 1 + len(enc_length)
997
new_chunks = ['d', enc_length, delta]
998
self._delta_index.add_delta_source(delta, len_mini_header)
1000
start = self.endpoint
1001
chunk_start = len(self.chunks)
1002
# Now output these bytes
1003
self._output_chunks(new_chunks)
1004
self.input_bytes += input_len
1005
chunk_end = len(self.chunks)
1006
self.labels_deltas[key] = (start, chunk_start,
1007
self.endpoint, chunk_end)
1008
if not self._delta_index._source_offset == self.endpoint:
1009
raise AssertionError('the delta index is out of sync'
1010
'with the output lines %s != %s'
1011
% (self._delta_index._source_offset, self.endpoint))
1012
return start, self.endpoint, type
1014
def _output_chunks(self, new_chunks):
1015
"""Output some chunks.
1017
:param new_chunks: The chunks to output.
1019
self._last = (len(self.chunks), self.endpoint)
1020
endpoint = self.endpoint
1021
self.chunks.extend(new_chunks)
1022
endpoint += sum(map(len, new_chunks))
1023
self.endpoint = endpoint
1026
def make_pack_factory(graph, delta, keylength, inconsistency_fatal=True):
1027
"""Create a factory for creating a pack based groupcompress.
1029
This is only functional enough to run interface tests, it doesn't try to
1030
provide a full pack environment.
1032
:param graph: Store a graph.
1033
:param delta: Delta compress contents.
1034
:param keylength: How long should keys be.
1036
def factory(transport):
1041
graph_index = BTreeBuilder(reference_lists=ref_length,
1042
key_elements=keylength)
1043
stream = transport.open_write_stream('newpack')
1044
writer = pack.ContainerWriter(stream.write)
1046
index = _GCGraphIndex(graph_index, lambda:True, parents=parents,
1047
add_callback=graph_index.add_nodes,
1048
inconsistency_fatal=inconsistency_fatal)
1049
access = knit._DirectPackAccess({})
1050
access.set_writer(writer, graph_index, (transport, 'newpack'))
1051
result = GroupCompressVersionedFiles(index, access, delta)
1052
result.stream = stream
1053
result.writer = writer
1058
def cleanup_pack_group(versioned_files):
1059
versioned_files.writer.end()
1060
versioned_files.stream.close()
1063
class _BatchingBlockFetcher(object):
1064
"""Fetch group compress blocks in batches.
1066
:ivar total_bytes: int of expected number of bytes needed to fetch the
1067
currently pending batch.
1070
def __init__(self, gcvf, locations):
1072
self.locations = locations
1074
self.batch_memos = {}
1075
self.memos_to_get = []
1076
self.total_bytes = 0
1077
self.last_read_memo = None
1080
def add_key(self, key):
1081
"""Add another to key to fetch.
1083
:return: The estimated number of bytes needed to fetch the batch so
1086
self.keys.append(key)
1087
index_memo, _, _, _ = self.locations[key]
1088
read_memo = index_memo[0:3]
1089
# Three possibilities for this read_memo:
1090
# - it's already part of this batch; or
1091
# - it's not yet part of this batch, but is already cached; or
1092
# - it's not yet part of this batch and will need to be fetched.
1093
if read_memo in self.batch_memos:
1094
# This read memo is already in this batch.
1095
return self.total_bytes
1097
cached_block = self.gcvf._group_cache[read_memo]
1099
# This read memo is new to this batch, and the data isn't cached
1101
self.batch_memos[read_memo] = None
1102
self.memos_to_get.append(read_memo)
1103
byte_length = read_memo[2]
1104
self.total_bytes += byte_length
1106
# This read memo is new to this batch, but cached.
1107
# Keep a reference to the cached block in batch_memos because it's
1108
# certain that we'll use it when this batch is processed, but
1109
# there's a risk that it would fall out of _group_cache between now
1111
self.batch_memos[read_memo] = cached_block
1112
return self.total_bytes
1114
def _flush_manager(self):
1115
if self.manager is not None:
1116
for factory in self.manager.get_record_stream():
1119
self.last_read_memo = None
1121
def yield_factories(self, full_flush=False):
1122
"""Yield factories for keys added since the last yield. They will be
1123
returned in the order they were added via add_key.
1125
:param full_flush: by default, some results may not be returned in case
1126
they can be part of the next batch. If full_flush is True, then
1127
all results are returned.
1129
if self.manager is None and not self.keys:
1131
# Fetch all memos in this batch.
1132
blocks = self.gcvf._get_blocks(self.memos_to_get)
1133
# Turn blocks into factories and yield them.
1134
memos_to_get_stack = list(self.memos_to_get)
1135
memos_to_get_stack.reverse()
1136
for key in self.keys:
1137
index_memo, _, parents, _ = self.locations[key]
1138
read_memo = index_memo[:3]
1139
if self.last_read_memo != read_memo:
1140
# We are starting a new block. If we have a
1141
# manager, we have found everything that fits for
1142
# now, so yield records
1143
for factory in self._flush_manager():
1145
# Now start a new manager.
1146
if memos_to_get_stack and memos_to_get_stack[-1] == read_memo:
1147
# The next block from _get_blocks will be the block we
1149
block_read_memo, block = blocks.next()
1150
if block_read_memo != read_memo:
1151
raise AssertionError(
1152
"block_read_memo out of sync with read_memo"
1153
"(%r != %r)" % (block_read_memo, read_memo))
1154
self.batch_memos[read_memo] = block
1155
memos_to_get_stack.pop()
1157
block = self.batch_memos[read_memo]
1158
self.manager = _LazyGroupContentManager(block)
1159
self.last_read_memo = read_memo
1160
start, end = index_memo[3:5]
1161
self.manager.add_factory(key, parents, start, end)
1163
for factory in self._flush_manager():
1166
self.batch_memos.clear()
1167
del self.memos_to_get[:]
1168
self.total_bytes = 0
1171
class GroupCompressVersionedFiles(VersionedFiles):
1172
"""A group-compress based VersionedFiles implementation."""
1174
def __init__(self, index, access, delta=True, _unadded_refs=None):
1175
"""Create a GroupCompressVersionedFiles object.
1177
:param index: The index object storing access and graph data.
1178
:param access: The access object storing raw data.
1179
:param delta: Whether to delta compress or just entropy compress.
1180
:param _unadded_refs: private parameter, don't use.
1183
self._access = access
1185
if _unadded_refs is None:
1187
self._unadded_refs = _unadded_refs
1188
self._group_cache = LRUSizeCache(max_size=50*1024*1024)
1189
self._fallback_vfs = []
1191
def without_fallbacks(self):
1192
"""Return a clone of this object without any fallbacks configured."""
1193
return GroupCompressVersionedFiles(self._index, self._access,
1194
self._delta, _unadded_refs=dict(self._unadded_refs))
1196
def add_lines(self, key, parents, lines, parent_texts=None,
1197
left_matching_blocks=None, nostore_sha=None, random_id=False,
1198
check_content=True):
1199
"""Add a text to the store.
1201
:param key: The key tuple of the text to add.
1202
:param parents: The parents key tuples of the text to add.
1203
:param lines: A list of lines. Each line must be a bytestring. And all
1204
of them except the last must be terminated with \n and contain no
1205
other \n's. The last line may either contain no \n's or a single
1206
terminating \n. If the lines list does meet this constraint the add
1207
routine may error or may succeed - but you will be unable to read
1208
the data back accurately. (Checking the lines have been split
1209
correctly is expensive and extremely unlikely to catch bugs so it
1210
is not done at runtime unless check_content is True.)
1211
:param parent_texts: An optional dictionary containing the opaque
1212
representations of some or all of the parents of version_id to
1213
allow delta optimisations. VERY IMPORTANT: the texts must be those
1214
returned by add_lines or data corruption can be caused.
1215
:param left_matching_blocks: a hint about which areas are common
1216
between the text and its left-hand-parent. The format is
1217
the SequenceMatcher.get_matching_blocks format.
1218
:param nostore_sha: Raise ExistingContent and do not add the lines to
1219
the versioned file if the digest of the lines matches this.
1220
:param random_id: If True a random id has been selected rather than
1221
an id determined by some deterministic process such as a converter
1222
from a foreign VCS. When True the backend may choose not to check
1223
for uniqueness of the resulting key within the versioned file, so
1224
this should only be done when the result is expected to be unique
1226
:param check_content: If True, the lines supplied are verified to be
1227
bytestrings that are correctly formed lines.
1228
:return: The text sha1, the number of bytes in the text, and an opaque
1229
representation of the inserted version which can be provided
1230
back to future add_lines calls in the parent_texts dictionary.
1232
self._index._check_write_ok()
1233
self._check_add(key, lines, random_id, check_content)
1235
# The caller might pass None if there is no graph data, but kndx
1236
# indexes can't directly store that, so we give them
1237
# an empty tuple instead.
1239
# double handling for now. Make it work until then.
1240
length = sum(map(len, lines))
1241
record = ChunkedContentFactory(key, parents, None, lines)
1242
sha1 = list(self._insert_record_stream([record], random_id=random_id,
1243
nostore_sha=nostore_sha))[0]
1244
return sha1, length, None
1246
def _add_text(self, key, parents, text, nostore_sha=None, random_id=False):
1247
"""See VersionedFiles._add_text()."""
1248
self._index._check_write_ok()
1249
self._check_add(key, None, random_id, check_content=False)
1250
if text.__class__ is not str:
1251
raise errors.BzrBadParameterUnicode("text")
1253
# The caller might pass None if there is no graph data, but kndx
1254
# indexes can't directly store that, so we give them
1255
# an empty tuple instead.
1257
# double handling for now. Make it work until then.
1259
record = FulltextContentFactory(key, parents, None, text)
1260
sha1 = list(self._insert_record_stream([record], random_id=random_id,
1261
nostore_sha=nostore_sha))[0]
1262
return sha1, length, None
1264
def add_fallback_versioned_files(self, a_versioned_files):
1265
"""Add a source of texts for texts not present in this knit.
1267
:param a_versioned_files: A VersionedFiles object.
1269
self._fallback_vfs.append(a_versioned_files)
1271
def annotate(self, key):
1272
"""See VersionedFiles.annotate."""
1273
ann = annotate.Annotator(self)
1274
return ann.annotate_flat(key)
1276
def get_annotator(self):
1277
return annotate.Annotator(self)
1279
def check(self, progress_bar=None, keys=None):
1280
"""See VersionedFiles.check()."""
1283
for record in self.get_record_stream(keys, 'unordered', True):
1284
record.get_bytes_as('fulltext')
1286
return self.get_record_stream(keys, 'unordered', True)
1288
def clear_cache(self):
1289
"""See VersionedFiles.clear_cache()"""
1290
self._group_cache.clear()
1291
self._index._graph_index.clear_cache()
1292
self._index._int_cache.clear()
1294
def _check_add(self, key, lines, random_id, check_content):
1295
"""check that version_id and lines are safe to add."""
1296
version_id = key[-1]
1297
if version_id is not None:
1298
if osutils.contains_whitespace(version_id):
1299
raise errors.InvalidRevisionId(version_id, self)
1300
self.check_not_reserved_id(version_id)
1301
# TODO: If random_id==False and the key is already present, we should
1302
# probably check that the existing content is identical to what is
1303
# being inserted, and otherwise raise an exception. This would make
1304
# the bundle code simpler.
1306
self._check_lines_not_unicode(lines)
1307
self._check_lines_are_lines(lines)
1309
def get_known_graph_ancestry(self, keys):
1310
"""Get a KnownGraph instance with the ancestry of keys."""
1311
# Note that this is identical to
1312
# KnitVersionedFiles.get_known_graph_ancestry, but they don't share
1314
parent_map, missing_keys = self._index.find_ancestry(keys)
1315
for fallback in self._fallback_vfs:
1316
if not missing_keys:
1318
(f_parent_map, f_missing_keys) = fallback._index.find_ancestry(
1320
parent_map.update(f_parent_map)
1321
missing_keys = f_missing_keys
1322
kg = _mod_graph.KnownGraph(parent_map)
1325
def get_parent_map(self, keys):
1326
"""Get a map of the graph parents of keys.
1328
:param keys: The keys to look up parents for.
1329
:return: A mapping from keys to parents. Absent keys are absent from
1332
return self._get_parent_map_with_sources(keys)[0]
1334
def _get_parent_map_with_sources(self, keys):
1335
"""Get a map of the parents of keys.
1337
:param keys: The keys to look up parents for.
1338
:return: A tuple. The first element is a mapping from keys to parents.
1339
Absent keys are absent from the mapping. The second element is a
1340
list with the locations each key was found in. The first element
1341
is the in-this-knit parents, the second the first fallback source,
1345
sources = [self._index] + self._fallback_vfs
1348
for source in sources:
1351
new_result = source.get_parent_map(missing)
1352
source_results.append(new_result)
1353
result.update(new_result)
1354
missing.difference_update(set(new_result))
1355
return result, source_results
1357
def _get_blocks(self, read_memos):
1358
"""Get GroupCompressBlocks for the given read_memos.
1360
:returns: a series of (read_memo, block) pairs, in the order they were
1364
for read_memo in read_memos:
1366
block = self._group_cache[read_memo]
1370
cached[read_memo] = block
1372
not_cached_seen = set()
1373
for read_memo in read_memos:
1374
if read_memo in cached:
1375
# Don't fetch what we already have
1377
if read_memo in not_cached_seen:
1378
# Don't try to fetch the same data twice
1380
not_cached.append(read_memo)
1381
not_cached_seen.add(read_memo)
1382
raw_records = self._access.get_raw_records(not_cached)
1383
for read_memo in read_memos:
1385
yield read_memo, cached[read_memo]
1387
# Read the block, and cache it.
1388
zdata = raw_records.next()
1389
block = GroupCompressBlock.from_bytes(zdata)
1390
self._group_cache[read_memo] = block
1391
cached[read_memo] = block
1392
yield read_memo, block
1394
def get_missing_compression_parent_keys(self):
1395
"""Return the keys of missing compression parents.
1397
Missing compression parents occur when a record stream was missing
1398
basis texts, or a index was scanned that had missing basis texts.
1400
# GroupCompress cannot currently reference texts that are not in the
1401
# group, so this is valid for now
1404
def get_record_stream(self, keys, ordering, include_delta_closure):
1405
"""Get a stream of records for keys.
1407
:param keys: The keys to include.
1408
:param ordering: Either 'unordered' or 'topological'. A topologically
1409
sorted stream has compression parents strictly before their
1411
:param include_delta_closure: If True then the closure across any
1412
compression parents will be included (in the opaque data).
1413
:return: An iterator of ContentFactory objects, each of which is only
1414
valid until the iterator is advanced.
1416
# keys might be a generator
1417
orig_keys = list(keys)
1421
if (not self._index.has_graph
1422
and ordering in ('topological', 'groupcompress')):
1423
# Cannot topological order when no graph has been stored.
1424
# but we allow 'as-requested' or 'unordered'
1425
ordering = 'unordered'
1427
remaining_keys = keys
1430
keys = set(remaining_keys)
1431
for content_factory in self._get_remaining_record_stream(keys,
1432
orig_keys, ordering, include_delta_closure):
1433
remaining_keys.discard(content_factory.key)
1434
yield content_factory
1436
except errors.RetryWithNewPacks, e:
1437
self._access.reload_or_raise(e)
1439
def _find_from_fallback(self, missing):
1440
"""Find whatever keys you can from the fallbacks.
1442
:param missing: A set of missing keys. This set will be mutated as keys
1443
are found from a fallback_vfs
1444
:return: (parent_map, key_to_source_map, source_results)
1445
parent_map the overall key => parent_keys
1446
key_to_source_map a dict from {key: source}
1447
source_results a list of (source: keys)
1450
key_to_source_map = {}
1452
for source in self._fallback_vfs:
1455
source_parents = source.get_parent_map(missing)
1456
parent_map.update(source_parents)
1457
source_parents = list(source_parents)
1458
source_results.append((source, source_parents))
1459
key_to_source_map.update((key, source) for key in source_parents)
1460
missing.difference_update(source_parents)
1461
return parent_map, key_to_source_map, source_results
1463
def _get_ordered_source_keys(self, ordering, parent_map, key_to_source_map):
1464
"""Get the (source, [keys]) list.
1466
The returned objects should be in the order defined by 'ordering',
1467
which can weave between different sources.
1468
:param ordering: Must be one of 'topological' or 'groupcompress'
1469
:return: List of [(source, [keys])] tuples, such that all keys are in
1470
the defined order, regardless of source.
1472
if ordering == 'topological':
1473
present_keys = topo_sort(parent_map)
1475
# ordering == 'groupcompress'
1476
# XXX: This only optimizes for the target ordering. We may need
1477
# to balance that with the time it takes to extract
1478
# ordering, by somehow grouping based on
1479
# locations[key][0:3]
1480
present_keys = sort_gc_optimal(parent_map)
1481
# Now group by source:
1483
current_source = None
1484
for key in present_keys:
1485
source = key_to_source_map.get(key, self)
1486
if source is not current_source:
1487
source_keys.append((source, []))
1488
current_source = source
1489
source_keys[-1][1].append(key)
1492
def _get_as_requested_source_keys(self, orig_keys, locations, unadded_keys,
1495
current_source = None
1496
for key in orig_keys:
1497
if key in locations or key in unadded_keys:
1499
elif key in key_to_source_map:
1500
source = key_to_source_map[key]
1503
if source is not current_source:
1504
source_keys.append((source, []))
1505
current_source = source
1506
source_keys[-1][1].append(key)
1509
def _get_io_ordered_source_keys(self, locations, unadded_keys,
1512
# This is the group the bytes are stored in, followed by the
1513
# location in the group
1514
return locations[key][0]
1515
present_keys = sorted(locations.iterkeys(), key=get_group)
1516
# We don't have an ordering for keys in the in-memory object, but
1517
# lets process the in-memory ones first.
1518
present_keys = list(unadded_keys) + present_keys
1519
# Now grab all of the ones from other sources
1520
source_keys = [(self, present_keys)]
1521
source_keys.extend(source_result)
1524
def _get_remaining_record_stream(self, keys, orig_keys, ordering,
1525
include_delta_closure):
1526
"""Get a stream of records for keys.
1528
:param keys: The keys to include.
1529
:param ordering: one of 'unordered', 'topological', 'groupcompress' or
1531
:param include_delta_closure: If True then the closure across any
1532
compression parents will be included (in the opaque data).
1533
:return: An iterator of ContentFactory objects, each of which is only
1534
valid until the iterator is advanced.
1537
locations = self._index.get_build_details(keys)
1538
unadded_keys = set(self._unadded_refs).intersection(keys)
1539
missing = keys.difference(locations)
1540
missing.difference_update(unadded_keys)
1541
(fallback_parent_map, key_to_source_map,
1542
source_result) = self._find_from_fallback(missing)
1543
if ordering in ('topological', 'groupcompress'):
1544
# would be better to not globally sort initially but instead
1545
# start with one key, recurse to its oldest parent, then grab
1546
# everything in the same group, etc.
1547
parent_map = dict((key, details[2]) for key, details in
1548
locations.iteritems())
1549
for key in unadded_keys:
1550
parent_map[key] = self._unadded_refs[key]
1551
parent_map.update(fallback_parent_map)
1552
source_keys = self._get_ordered_source_keys(ordering, parent_map,
1554
elif ordering == 'as-requested':
1555
source_keys = self._get_as_requested_source_keys(orig_keys,
1556
locations, unadded_keys, key_to_source_map)
1558
# We want to yield the keys in a semi-optimal (read-wise) ordering.
1559
# Otherwise we thrash the _group_cache and destroy performance
1560
source_keys = self._get_io_ordered_source_keys(locations,
1561
unadded_keys, source_result)
1563
yield AbsentContentFactory(key)
1564
# Batch up as many keys as we can until either:
1565
# - we encounter an unadded ref, or
1566
# - we run out of keys, or
1567
# - the total bytes to retrieve for this batch > BATCH_SIZE
1568
batcher = _BatchingBlockFetcher(self, locations)
1569
for source, keys in source_keys:
1572
if key in self._unadded_refs:
1573
# Flush batch, then yield unadded ref from
1575
for factory in batcher.yield_factories(full_flush=True):
1577
bytes, sha1 = self._compressor.extract(key)
1578
parents = self._unadded_refs[key]
1579
yield FulltextContentFactory(key, parents, sha1, bytes)
1581
if batcher.add_key(key) > BATCH_SIZE:
1582
# Ok, this batch is big enough. Yield some results.
1583
for factory in batcher.yield_factories():
1586
for factory in batcher.yield_factories(full_flush=True):
1588
for record in source.get_record_stream(keys, ordering,
1589
include_delta_closure):
1591
for factory in batcher.yield_factories(full_flush=True):
1594
def get_sha1s(self, keys):
1595
"""See VersionedFiles.get_sha1s()."""
1597
for record in self.get_record_stream(keys, 'unordered', True):
1598
if record.sha1 != None:
1599
result[record.key] = record.sha1
1601
if record.storage_kind != 'absent':
1602
result[record.key] = osutils.sha_string(
1603
record.get_bytes_as('fulltext'))
1606
def insert_record_stream(self, stream):
1607
"""Insert a record stream into this container.
1609
:param stream: A stream of records to insert.
1611
:seealso VersionedFiles.get_record_stream:
1613
# XXX: Setting random_id=True makes
1614
# test_insert_record_stream_existing_keys fail for groupcompress and
1615
# groupcompress-nograph, this needs to be revisited while addressing
1616
# 'bzr branch' performance issues.
1617
for _ in self._insert_record_stream(stream, random_id=False):
1620
def _insert_record_stream(self, stream, random_id=False, nostore_sha=None,
1622
"""Internal core to insert a record stream into this container.
1624
This helper function has a different interface than insert_record_stream
1625
to allow add_lines to be minimal, but still return the needed data.
1627
:param stream: A stream of records to insert.
1628
:param nostore_sha: If the sha1 of a given text matches nostore_sha,
1629
raise ExistingContent, rather than committing the new text.
1630
:param reuse_blocks: If the source is streaming from
1631
groupcompress-blocks, just insert the blocks as-is, rather than
1632
expanding the texts and inserting again.
1633
:return: An iterator over the sha1 of the inserted records.
1634
:seealso insert_record_stream:
1638
def get_adapter(adapter_key):
1640
return adapters[adapter_key]
1642
adapter_factory = adapter_registry.get(adapter_key)
1643
adapter = adapter_factory(self)
1644
adapters[adapter_key] = adapter
1646
# This will go up to fulltexts for gc to gc fetching, which isn't
1648
self._compressor = GroupCompressor()
1649
self._unadded_refs = {}
1652
bytes_len, chunks = self._compressor.flush().to_chunks()
1653
self._compressor = GroupCompressor()
1654
# Note: At this point we still have 1 copy of the fulltext (in
1655
# record and the var 'bytes'), and this generates 2 copies of
1656
# the compressed text (one for bytes, one in chunks)
1657
# TODO: Push 'chunks' down into the _access api, so that we don't
1658
# have to double compressed memory here
1659
# TODO: Figure out how to indicate that we would be happy to free
1660
# the fulltext content at this point. Note that sometimes we
1661
# will want it later (streaming CHK pages), but most of the
1662
# time we won't (everything else)
1663
bytes = ''.join(chunks)
1665
index, start, length = self._access.add_raw_records(
1666
[(None, len(bytes))], bytes)[0]
1668
for key, reads, refs in keys_to_add:
1669
nodes.append((key, "%d %d %s" % (start, length, reads), refs))
1670
self._index.add_records(nodes, random_id=random_id)
1671
self._unadded_refs = {}
1675
max_fulltext_len = 0
1676
max_fulltext_prefix = None
1677
insert_manager = None
1680
# XXX: TODO: remove this, it is just for safety checking for now
1681
inserted_keys = set()
1682
reuse_this_block = reuse_blocks
1683
for record in stream:
1684
# Raise an error when a record is missing.
1685
if record.storage_kind == 'absent':
1686
raise errors.RevisionNotPresent(record.key, self)
1688
if record.key in inserted_keys:
1689
trace.note('Insert claimed random_id=True,'
1690
' but then inserted %r two times', record.key)
1692
inserted_keys.add(record.key)
1694
# If the reuse_blocks flag is set, check to see if we can just
1695
# copy a groupcompress block as-is.
1696
# We only check on the first record (groupcompress-block) not
1697
# on all of the (groupcompress-block-ref) entries.
1698
# The reuse_this_block flag is then kept for as long as
1699
if record.storage_kind == 'groupcompress-block':
1700
# Check to see if we really want to re-use this block
1701
insert_manager = record._manager
1702
reuse_this_block = insert_manager.check_is_well_utilized()
1704
reuse_this_block = False
1705
if reuse_this_block:
1706
# We still want to reuse this block
1707
if record.storage_kind == 'groupcompress-block':
1708
# Insert the raw block into the target repo
1709
insert_manager = record._manager
1710
bytes = record._manager._block.to_bytes()
1711
_, start, length = self._access.add_raw_records(
1712
[(None, len(bytes))], bytes)[0]
1715
block_length = length
1716
if record.storage_kind in ('groupcompress-block',
1717
'groupcompress-block-ref'):
1718
if insert_manager is None:
1719
raise AssertionError('No insert_manager set')
1720
if insert_manager is not record._manager:
1721
raise AssertionError('insert_manager does not match'
1722
' the current record, we cannot be positive'
1723
' that the appropriate content was inserted.'
1725
value = "%d %d %d %d" % (block_start, block_length,
1726
record._start, record._end)
1727
nodes = [(record.key, value, (record.parents,))]
1728
# TODO: Consider buffering up many nodes to be added, not
1729
# sure how much overhead this has, but we're seeing
1730
# ~23s / 120s in add_records calls
1731
self._index.add_records(nodes, random_id=random_id)
1734
bytes = record.get_bytes_as('fulltext')
1735
except errors.UnavailableRepresentation:
1736
adapter_key = record.storage_kind, 'fulltext'
1737
adapter = get_adapter(adapter_key)
1738
bytes = adapter.get_bytes(record)
1739
if len(record.key) > 1:
1740
prefix = record.key[0]
1741
soft = (prefix == last_prefix)
1745
if max_fulltext_len < len(bytes):
1746
max_fulltext_len = len(bytes)
1747
max_fulltext_prefix = prefix
1748
(found_sha1, start_point, end_point,
1749
type) = self._compressor.compress(record.key,
1750
bytes, record.sha1, soft=soft,
1751
nostore_sha=nostore_sha)
1752
# delta_ratio = float(len(bytes)) / (end_point - start_point)
1753
# Check if we want to continue to include that text
1754
if (prefix == max_fulltext_prefix
1755
and end_point < 2 * max_fulltext_len):
1756
# As long as we are on the same file_id, we will fill at least
1757
# 2 * max_fulltext_len
1758
start_new_block = False
1759
elif end_point > 4*1024*1024:
1760
start_new_block = True
1761
elif (prefix is not None and prefix != last_prefix
1762
and end_point > 2*1024*1024):
1763
start_new_block = True
1765
start_new_block = False
1766
last_prefix = prefix
1768
self._compressor.pop_last()
1770
max_fulltext_len = len(bytes)
1771
(found_sha1, start_point, end_point,
1772
type) = self._compressor.compress(record.key, bytes,
1774
if record.key[-1] is None:
1775
key = record.key[:-1] + ('sha1:' + found_sha1,)
1778
self._unadded_refs[key] = record.parents
1780
as_st = static_tuple.StaticTuple.from_sequence
1781
if record.parents is not None:
1782
parents = as_st([as_st(p) for p in record.parents])
1785
refs = static_tuple.StaticTuple(parents)
1786
keys_to_add.append((key, '%d %d' % (start_point, end_point), refs))
1787
if len(keys_to_add):
1789
self._compressor = None
1791
def iter_lines_added_or_present_in_keys(self, keys, pb=None):
1792
"""Iterate over the lines in the versioned files from keys.
1794
This may return lines from other keys. Each item the returned
1795
iterator yields is a tuple of a line and a text version that that line
1796
is present in (not introduced in).
1798
Ordering of results is in whatever order is most suitable for the
1799
underlying storage format.
1801
If a progress bar is supplied, it may be used to indicate progress.
1802
The caller is responsible for cleaning up progress bars (because this
1806
* Lines are normalised by the underlying store: they will all have \n
1808
* Lines are returned in arbitrary order.
1810
:return: An iterator over (line, key).
1814
# we don't care about inclusions, the caller cares.
1815
# but we need to setup a list of records to visit.
1816
# we need key, position, length
1817
for key_idx, record in enumerate(self.get_record_stream(keys,
1818
'unordered', True)):
1819
# XXX: todo - optimise to use less than full texts.
1822
pb.update('Walking content', key_idx, total)
1823
if record.storage_kind == 'absent':
1824
raise errors.RevisionNotPresent(key, self)
1825
lines = osutils.split_lines(record.get_bytes_as('fulltext'))
1829
pb.update('Walking content', total, total)
1832
"""See VersionedFiles.keys."""
1833
if 'evil' in debug.debug_flags:
1834
trace.mutter_callsite(2, "keys scales with size of history")
1835
sources = [self._index] + self._fallback_vfs
1837
for source in sources:
1838
result.update(source.keys())
1842
class _GCBuildDetails(object):
1843
"""A blob of data about the build details.
1845
This stores the minimal data, which then allows compatibility with the old
1846
api, without taking as much memory.
1849
__slots__ = ('_index', '_group_start', '_group_end', '_basis_end',
1850
'_delta_end', '_parents')
1853
compression_parent = None
1855
def __init__(self, parents, position_info):
1856
self._parents = parents
1857
(self._index, self._group_start, self._group_end, self._basis_end,
1858
self._delta_end) = position_info
1861
return '%s(%s, %s)' % (self.__class__.__name__,
1862
self.index_memo, self._parents)
1865
def index_memo(self):
1866
return (self._index, self._group_start, self._group_end,
1867
self._basis_end, self._delta_end)
1870
def record_details(self):
1871
return static_tuple.StaticTuple(self.method, None)
1873
def __getitem__(self, offset):
1874
"""Compatibility thunk to act like a tuple."""
1876
return self.index_memo
1878
return self.compression_parent # Always None
1880
return self._parents
1882
return self.record_details
1884
raise IndexError('offset out of range')
1890
class _GCGraphIndex(object):
1891
"""Mapper from GroupCompressVersionedFiles needs into GraphIndex storage."""
1893
def __init__(self, graph_index, is_locked, parents=True,
1894
add_callback=None, track_external_parent_refs=False,
1895
inconsistency_fatal=True, track_new_keys=False):
1896
"""Construct a _GCGraphIndex on a graph_index.
1898
:param graph_index: An implementation of bzrlib.index.GraphIndex.
1899
:param is_locked: A callback, returns True if the index is locked and
1901
:param parents: If True, record knits parents, if not do not record
1903
:param add_callback: If not None, allow additions to the index and call
1904
this callback with a list of added GraphIndex nodes:
1905
[(node, value, node_refs), ...]
1906
:param track_external_parent_refs: As keys are added, keep track of the
1907
keys they reference, so that we can query get_missing_parents(),
1909
:param inconsistency_fatal: When asked to add records that are already
1910
present, and the details are inconsistent with the existing
1911
record, raise an exception instead of warning (and skipping the
1914
self._add_callback = add_callback
1915
self._graph_index = graph_index
1916
self._parents = parents
1917
self.has_graph = parents
1918
self._is_locked = is_locked
1919
self._inconsistency_fatal = inconsistency_fatal
1920
# GroupCompress records tend to have the same 'group' start + offset
1921
# repeated over and over, this creates a surplus of ints
1922
self._int_cache = {}
1923
if track_external_parent_refs:
1924
self._key_dependencies = knit._KeyRefs(
1925
track_new_keys=track_new_keys)
1927
self._key_dependencies = None
1929
def add_records(self, records, random_id=False):
1930
"""Add multiple records to the index.
1932
This function does not insert data into the Immutable GraphIndex
1933
backing the KnitGraphIndex, instead it prepares data for insertion by
1934
the caller and checks that it is safe to insert then calls
1935
self._add_callback with the prepared GraphIndex nodes.
1937
:param records: a list of tuples:
1938
(key, options, access_memo, parents).
1939
:param random_id: If True the ids being added were randomly generated
1940
and no check for existence will be performed.
1942
if not self._add_callback:
1943
raise errors.ReadOnlyError(self)
1944
# we hope there are no repositories with inconsistent parentage
1949
for (key, value, refs) in records:
1950
if not self._parents:
1954
raise errors.KnitCorrupt(self,
1955
"attempt to add node with parents "
1956
"in parentless index.")
1959
keys[key] = (value, refs)
1962
present_nodes = self._get_entries(keys)
1963
for (index, key, value, node_refs) in present_nodes:
1964
# Sometimes these are passed as a list rather than a tuple
1965
node_refs = static_tuple.as_tuples(node_refs)
1966
passed = static_tuple.as_tuples(keys[key])
1967
if node_refs != passed[1]:
1968
details = '%s %s %s' % (key, (value, node_refs), passed)
1969
if self._inconsistency_fatal:
1970
raise errors.KnitCorrupt(self, "inconsistent details"
1971
" in add_records: %s" %
1974
trace.warning("inconsistent details in skipped"
1975
" record: %s", details)
1981
for key, (value, node_refs) in keys.iteritems():
1982
result.append((key, value, node_refs))
1984
for key, (value, node_refs) in keys.iteritems():
1985
result.append((key, value))
1987
key_dependencies = self._key_dependencies
1988
if key_dependencies is not None:
1990
for key, value, refs in records:
1992
key_dependencies.add_references(key, parents)
1994
for key, value, refs in records:
1995
new_keys.add_key(key)
1996
self._add_callback(records)
1998
def _check_read(self):
1999
"""Raise an exception if reads are not permitted."""
2000
if not self._is_locked():
2001
raise errors.ObjectNotLocked(self)
2003
def _check_write_ok(self):
2004
"""Raise an exception if writes are not permitted."""
2005
if not self._is_locked():
2006
raise errors.ObjectNotLocked(self)
2008
def _get_entries(self, keys, check_present=False):
2009
"""Get the entries for keys.
2011
Note: Callers are responsible for checking that the index is locked
2012
before calling this method.
2014
:param keys: An iterable of index key tuples.
2019
for node in self._graph_index.iter_entries(keys):
2021
found_keys.add(node[1])
2023
# adapt parentless index to the rest of the code.
2024
for node in self._graph_index.iter_entries(keys):
2025
yield node[0], node[1], node[2], ()
2026
found_keys.add(node[1])
2028
missing_keys = keys.difference(found_keys)
2030
raise errors.RevisionNotPresent(missing_keys.pop(), self)
2032
def find_ancestry(self, keys):
2033
"""See CombinedGraphIndex.find_ancestry"""
2034
return self._graph_index.find_ancestry(keys, 0)
2036
def get_parent_map(self, keys):
2037
"""Get a map of the parents of keys.
2039
:param keys: The keys to look up parents for.
2040
:return: A mapping from keys to parents. Absent keys are absent from
2044
nodes = self._get_entries(keys)
2048
result[node[1]] = node[3][0]
2051
result[node[1]] = None
2054
def get_missing_parents(self):
2055
"""Return the keys of missing parents."""
2056
# Copied from _KnitGraphIndex.get_missing_parents
2057
# We may have false positives, so filter those out.
2058
self._key_dependencies.satisfy_refs_for_keys(
2059
self.get_parent_map(self._key_dependencies.get_unsatisfied_refs()))
2060
return frozenset(self._key_dependencies.get_unsatisfied_refs())
2062
def get_build_details(self, keys):
2063
"""Get the various build details for keys.
2065
Ghosts are omitted from the result.
2067
:param keys: An iterable of keys.
2068
:return: A dict of key:
2069
(index_memo, compression_parent, parents, record_details).
2071
opaque structure to pass to read_records to extract the raw
2074
Content that this record is built upon, may be None
2076
Logical parents of this node
2078
extra information about the content which needs to be passed to
2079
Factory.parse_record
2083
entries = self._get_entries(keys)
2084
for entry in entries:
2086
if not self._parents:
2089
parents = entry[3][0]
2090
details = _GCBuildDetails(parents, self._node_to_position(entry))
2091
result[key] = details
2095
"""Get all the keys in the collection.
2097
The keys are not ordered.
2100
return [node[1] for node in self._graph_index.iter_all_entries()]
2102
def _node_to_position(self, node):
2103
"""Convert an index value to position details."""
2104
bits = node[2].split(' ')
2105
# It would be nice not to read the entire gzip.
2106
# start and stop are put into _int_cache because they are very common.
2107
# They define the 'group' that an entry is in, and many groups can have
2108
# thousands of objects.
2109
# Branching Launchpad, for example, saves ~600k integers, at 12 bytes
2110
# each, or about 7MB. Note that it might be even more when you consider
2111
# how PyInt is allocated in separate slabs. And you can't return a slab
2112
# to the OS if even 1 int on it is in use. Note though that Python uses
2113
# a LIFO when re-using PyInt slots, which might cause more
2115
start = int(bits[0])
2116
start = self._int_cache.setdefault(start, start)
2118
stop = self._int_cache.setdefault(stop, stop)
2119
basis_end = int(bits[2])
2120
delta_end = int(bits[3])
2121
# We can't use StaticTuple here, because node[0] is a BTreeGraphIndex
2123
return (node[0], start, stop, basis_end, delta_end)
2125
def scan_unvalidated_index(self, graph_index):
2126
"""Inform this _GCGraphIndex that there is an unvalidated index.
2128
This allows this _GCGraphIndex to keep track of any missing
2129
compression parents we may want to have filled in to make those
2130
indices valid. It also allows _GCGraphIndex to track any new keys.
2132
:param graph_index: A GraphIndex
2134
key_dependencies = self._key_dependencies
2135
if key_dependencies is None:
2137
for node in graph_index.iter_all_entries():
2138
# Add parent refs from graph_index (and discard parent refs
2139
# that the graph_index has).
2140
key_dependencies.add_references(node[1], node[3][0])
2143
from bzrlib._groupcompress_py import (
2145
apply_delta_to_source,
2148
decode_copy_instruction,
2152
from bzrlib._groupcompress_pyx import (
2154
apply_delta_to_source,
2159
GroupCompressor = PyrexGroupCompressor
2160
except ImportError, e:
2161
osutils.failed_to_load_extension(e)
2162
GroupCompressor = PythonGroupCompressor
added
removed
bzrlib/groupcompress.py
