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# Copyright (C) 2008, 2009 Canonical Ltd
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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"""Core compression logic for compressing streams of related files."""
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from 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 = 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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# TODO: If we re-use the same content block at different times during
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# get_record_stream(), it is possible that the first pass will
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# get inserted, triggering an extract/_ensure_content() which
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# will get rid of _z_content. And then the next use of the block
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# will try to access _z_content (to send it over the wire), and
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# fail because it is already extracted. Consider never releasing
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# _z_content because of this.
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if num_bytes is None:
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num_bytes = self._content_length
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elif (self._content_length is not None
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and num_bytes > self._content_length):
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raise AssertionError(
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'requested num_bytes (%d) > content length (%d)'
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% (num_bytes, self._content_length))
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# Expand the content if required
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if self._content is None:
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if self._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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if self._z_content is None:
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raise AssertionError('No content to decompress')
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if self._z_content == '':
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elif self._compressor_name == 'lzma':
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# We don't do partial lzma decomp yet
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self._content = pylzma.decompress(self._z_content)
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elif self._compressor_name == 'zlib':
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# Start a zlib decompressor
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if num_bytes is None:
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self._content = zlib.decompress(self._z_content)
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self._z_content_decompressor = zlib.decompressobj()
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# Seed the decompressor with the uncompressed bytes, so
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# that the rest of the code is simplified
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self._content = self._z_content_decompressor.decompress(
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self._z_content, num_bytes + _ZLIB_DECOMP_WINDOW)
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raise AssertionError('Unknown compressor: %r'
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% self._compressor_name)
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# Any bytes remaining to be decompressed will be in the decompressors
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# Do we have enough bytes already?
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if num_bytes is not None and len(self._content) >= num_bytes:
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if num_bytes is None and self._z_content_decompressor is None:
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# We must have already decompressed everything
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# If we got this far, and don't have a decompressor, something is wrong
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if self._z_content_decompressor is None:
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raise AssertionError(
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'No decompressor to decompress %d bytes' % num_bytes)
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remaining_decomp = self._z_content_decompressor.unconsumed_tail
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if num_bytes is None:
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# We don't know how much is left, but we'll decompress it all
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self._content += self._z_content_decompressor.decompress(
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# Note: There's what I consider a bug in zlib.decompressobj
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# If you pass back in the entire unconsumed_tail, only
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# this time you don't pass a max-size, it doesn't
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# change the unconsumed_tail back to None/''.
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# However, we know we are done with the whole stream
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self._z_content_decompressor = None
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# XXX: Why is this the only place in this routine we set this?
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self._content_length = len(self._content)
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if not remaining_decomp:
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raise AssertionError('Nothing left to decompress')
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needed_bytes = num_bytes - len(self._content)
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# We always set max_size to 32kB over the minimum needed, so that
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# zlib will give us as much as we really want.
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# TODO: If this isn't good enough, we could make a loop here,
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# that keeps expanding the request until we get enough
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self._content += self._z_content_decompressor.decompress(
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remaining_decomp, needed_bytes + _ZLIB_DECOMP_WINDOW)
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if len(self._content) < num_bytes:
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raise AssertionError('%d bytes wanted, only %d available'
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% (num_bytes, len(self._content)))
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if not self._z_content_decompressor.unconsumed_tail:
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# The stream is finished
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self._z_content_decompressor = None
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def _parse_bytes(self, bytes, pos):
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"""Read the various lengths from the header.
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This also populates the various 'compressed' buffers.
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:return: The position in bytes just after the last newline
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# At present, we have 2 integers for the compressed and uncompressed
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# content. In base10 (ascii) 14 bytes can represent > 1TB, so to avoid
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# checking too far, cap the search to 14 bytes.
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pos2 = bytes.index('\n', pos, pos + 14)
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self._z_content_length = int(bytes[pos:pos2])
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pos2 = bytes.index('\n', pos, pos + 14)
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self._content_length = int(bytes[pos:pos2])
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if len(bytes) != (pos + self._z_content_length):
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# XXX: Define some GCCorrupt error ?
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raise AssertionError('Invalid bytes: (%d) != %d + %d' %
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(len(bytes), pos, self._z_content_length))
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self._z_content = bytes[pos:]
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def from_bytes(cls, bytes):
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if bytes[:6] not in cls.GCB_KNOWN_HEADERS:
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raise ValueError('bytes did not start with any of %r'
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% (cls.GCB_KNOWN_HEADERS,))
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# XXX: why not testing the whole header ?
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out._compressor_name = 'zlib'
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elif bytes[4] == 'l':
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out._compressor_name = 'lzma'
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raise ValueError('unknown compressor: %r' % (bytes,))
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out._parse_bytes(bytes, 6)
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def extract(self, key, start, end, sha1=None):
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"""Extract the text for a specific key.
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:param key: The label used for this content
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:param sha1: TODO (should we validate only when sha1 is supplied?)
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:return: The bytes for the content
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if start == end == 0:
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self._ensure_content(end)
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# The bytes are 'f' or 'd' for the type, then a variable-length
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# base128 integer for the content size, then the actual content
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# We know that the variable-length integer won't be longer than 5
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# bytes (it takes 5 bytes to encode 2^32)
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c = self._content[start]
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raise ValueError('Unknown content control code: %s'
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content_len, len_len = decode_base128_int(
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self._content[start + 1:start + 6])
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content_start = start + 1 + len_len
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if end != content_start + content_len:
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raise ValueError('end != len according to field header'
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' %s != %s' % (end, content_start + content_len))
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bytes = self._content[content_start:end]
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bytes = apply_delta_to_source(self._content, content_start, end)
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def set_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 = 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 = 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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self._z_content = pylzma.compress(self._content)
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self._z_content_length = len(self._z_content)
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def _create_z_content_from_chunks(self):
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compressor = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION)
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compressed_chunks = map(compressor.compress, self._content_chunks)
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compressed_chunks.append(compressor.flush())
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self._z_content = ''.join(compressed_chunks)
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self._z_content_length = len(self._z_content)
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def _create_z_content(self):
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if self._z_content 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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self._create_z_content_from_chunks()
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self._z_content = zlib.compress(self._content)
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self._z_content_length = len(self._z_content)
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"""Encode the information into a byte stream."""
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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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'%d\n%d\n' % (self._z_content_length, self._content_length),
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return ''.join(chunks)
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def _dump(self, include_text=False):
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"""Take this block, and spit out a human-readable structure.
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:param include_text: Inserts also include text bits, chose whether you
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want this displayed in the dump or not.
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:return: A dump of the given block. The layout is something like:
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[('f', length), ('d', delta_length, text_length, [delta_info])]
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delta_info := [('i', num_bytes, text), ('c', offset, num_bytes),
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self._ensure_content()
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while pos < self._content_length:
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kind = self._content[pos]
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if kind not in ('f', 'd'):
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raise ValueError('invalid kind character: %r' % (kind,))
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content_len, len_len = decode_base128_int(
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self._content[pos:pos + 5])
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if content_len + pos > self._content_length:
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raise ValueError('invalid content_len %d for record @ pos %d'
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% (content_len, pos - len_len - 1))
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if kind == 'f': # Fulltext
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text = self._content[pos:pos+content_len]
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result.append(('f', content_len, text))
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result.append(('f', content_len))
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elif kind == 'd': # Delta
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delta_content = self._content[pos:pos+content_len]
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# The first entry in a delta is the decompressed length
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decomp_len, delta_pos = decode_base128_int(delta_content)
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result.append(('d', content_len, decomp_len, delta_info))
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while delta_pos < content_len:
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c = ord(delta_content[delta_pos])
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delta_pos) = decode_copy_instruction(delta_content, c,
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text = self._content[offset:offset+length]
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delta_info.append(('c', offset, length, text))
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delta_info.append(('c', offset, length))
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measured_len += length
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txt = delta_content[delta_pos:delta_pos+c]
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delta_info.append(('i', c, txt))
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if delta_pos != content_len:
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raise ValueError('Delta consumed a bad number of bytes:'
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' %d != %d' % (delta_pos, content_len))
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if measured_len != decomp_len:
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raise ValueError('Delta claimed fulltext was %d bytes, but'
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' extraction resulted in %d bytes'
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% (decomp_len, measured_len))
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class _LazyGroupCompressFactory(object):
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"""Yield content from a GroupCompressBlock on demand."""
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def __init__(self, key, parents, manager, start, end, first):
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"""Create a _LazyGroupCompressFactory
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:param key: The key of just this record
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:param parents: The parents of this key (possibly None)
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:param gc_block: A GroupCompressBlock object
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:param start: Offset of the first byte for this record in the
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:param end: Offset of the byte just after the end of this record
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(ie, bytes = content[start:end])
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:param first: Is this the first Factory for the given block?
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self.parents = parents
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# Note: This attribute coupled with Manager._factories creates a
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# reference cycle. Perhaps we would rather use a weakref(), or
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# find an appropriate time to release the ref. After the first
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# get_bytes_as call? After Manager.get_record_stream() returns
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self._manager = manager
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self.storage_kind = 'groupcompress-block'
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self.storage_kind = 'groupcompress-block-ref'
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return '%s(%s, first=%s)' % (self.__class__.__name__,
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self.key, self._first)
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def get_bytes_as(self, storage_kind):
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if storage_kind == self.storage_kind:
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# wire bytes, something...
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return self._manager._wire_bytes()
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if storage_kind in ('fulltext', 'chunked'):
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if self._bytes is None:
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# Grab and cache the raw bytes for this entry
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# and break the ref-cycle with _manager since we don't need it
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self._manager._prepare_for_extract()
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block = self._manager._block
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self._bytes = block.extract(self.key, self._start, self._end)
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# There are code paths that first extract as fulltext, and then
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# extract as storage_kind (smart fetch). So we don't break the
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# refcycle here, but instead in manager.get_record_stream()
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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):
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"""Return a byte stream suitable for transmitting over the wire."""
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self._check_rebuild_block()
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# The outer block starts with:
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# 'groupcompress-block\n'
665
# <length of compressed key info>\n
666
# <length of uncompressed info>\n
667
# <length of gc block>\n
670
lines = ['groupcompress-block\n']
671
# The minimal info we need is the key, the start offset, and the
672
# parents. The length and type are encoded in the record itself.
673
# However, passing in the other bits makes it easier. The list of
674
# keys, and the start offset, the length
676
# 1 line with parents, '' for ()
677
# 1 line for start offset
678
# 1 line for end byte
680
for factory in self._factories:
681
key_bytes = '\x00'.join(factory.key)
682
parents = factory.parents
684
parent_bytes = 'None:'
686
parent_bytes = '\t'.join('\x00'.join(key) for key in parents)
687
record_header = '%s\n%s\n%d\n%d\n' % (
688
key_bytes, parent_bytes, factory._start, factory._end)
689
header_lines.append(record_header)
690
# TODO: Can we break the refcycle at this point and set
691
# factory._manager = None?
692
header_bytes = ''.join(header_lines)
694
header_bytes_len = len(header_bytes)
695
z_header_bytes = zlib.compress(header_bytes)
697
z_header_bytes_len = len(z_header_bytes)
698
block_bytes = self._block.to_bytes()
699
lines.append('%d\n%d\n%d\n' % (z_header_bytes_len, header_bytes_len,
701
lines.append(z_header_bytes)
702
lines.append(block_bytes)
703
del z_header_bytes, block_bytes
704
return ''.join(lines)
707
def from_bytes(cls, bytes):
708
# TODO: This does extra string copying, probably better to do it a
710
(storage_kind, z_header_len, header_len,
711
block_len, rest) = bytes.split('\n', 4)
713
if storage_kind != 'groupcompress-block':
714
raise ValueError('Unknown storage kind: %s' % (storage_kind,))
715
z_header_len = int(z_header_len)
716
if len(rest) < z_header_len:
717
raise ValueError('Compressed header len shorter than all bytes')
718
z_header = rest[:z_header_len]
719
header_len = int(header_len)
720
header = zlib.decompress(z_header)
721
if len(header) != header_len:
722
raise ValueError('invalid length for decompressed bytes')
724
block_len = int(block_len)
725
if len(rest) != z_header_len + block_len:
726
raise ValueError('Invalid length for block')
727
block_bytes = rest[z_header_len:]
729
# So now we have a valid GCB, we just need to parse the factories that
731
header_lines = header.split('\n')
733
last = header_lines.pop()
735
raise ValueError('header lines did not end with a trailing'
737
if len(header_lines) % 4 != 0:
738
raise ValueError('The header was not an even multiple of 4 lines')
739
block = GroupCompressBlock.from_bytes(block_bytes)
742
for start in xrange(0, len(header_lines), 4):
744
key = tuple(header_lines[start].split('\x00'))
745
parents_line = header_lines[start+1]
746
if parents_line == 'None:':
749
parents = tuple([tuple(segment.split('\x00'))
750
for segment in parents_line.split('\t')
752
start_offset = int(header_lines[start+2])
753
end_offset = int(header_lines[start+3])
754
result.add_factory(key, parents, start_offset, end_offset)
758
def network_block_to_records(storage_kind, bytes, line_end):
759
if storage_kind != 'groupcompress-block':
760
raise ValueError('Unknown storage kind: %s' % (storage_kind,))
761
manager = _LazyGroupContentManager.from_bytes(bytes)
762
return manager.get_record_stream()
765
class _CommonGroupCompressor(object):
768
"""Create a GroupCompressor."""
773
self.labels_deltas = {}
774
self._delta_index = None # Set by the children
775
self._block = GroupCompressBlock()
777
def compress(self, key, bytes, expected_sha, nostore_sha=None, soft=False):
778
"""Compress lines with label key.
780
:param key: A key tuple. It is stored in the output
781
for identification of the text during decompression. If the last
782
element is 'None' it is replaced with the sha1 of the text -
784
:param bytes: The bytes to be compressed
785
:param expected_sha: If non-None, the sha the lines are believed to
786
have. During compression the sha is calculated; a mismatch will
788
:param nostore_sha: If the computed sha1 sum matches, we will raise
789
ExistingContent rather than adding the text.
790
:param soft: Do a 'soft' compression. This means that we require larger
791
ranges to match to be considered for a copy command.
793
:return: The sha1 of lines, the start and end offsets in the delta, and
794
the type ('fulltext' or 'delta').
796
:seealso VersionedFiles.add_lines:
798
if not bytes: # empty, like a dir entry, etc
799
if nostore_sha == _null_sha1:
800
raise errors.ExistingContent()
801
return _null_sha1, 0, 0, 'fulltext'
802
# we assume someone knew what they were doing when they passed it in
803
if expected_sha is not None:
806
sha1 = osutils.sha_string(bytes)
807
if nostore_sha is not None:
808
if sha1 == nostore_sha:
809
raise errors.ExistingContent()
811
key = key[:-1] + ('sha1:' + sha1,)
813
start, end, type = self._compress(key, bytes, len(bytes) / 2, soft)
814
return sha1, start, end, type
816
def _compress(self, key, bytes, max_delta_size, soft=False):
817
"""Compress lines with label key.
819
:param key: A key tuple. It is stored in the output for identification
820
of the text during decompression.
822
:param bytes: The bytes to be compressed
824
:param max_delta_size: The size above which we issue a fulltext instead
827
:param soft: Do a 'soft' compression. This means that we require larger
828
ranges to match to be considered for a copy command.
830
:return: The sha1 of lines, the start and end offsets in the delta, and
831
the type ('fulltext' or 'delta').
833
raise NotImplementedError(self._compress)
835
def extract(self, key):
836
"""Extract a key previously added to the compressor.
838
:param key: The key to extract.
839
:return: An iterable over bytes and the sha1.
841
(start_byte, start_chunk, end_byte, end_chunk) = self.labels_deltas[key]
842
delta_chunks = self.chunks[start_chunk:end_chunk]
843
stored_bytes = ''.join(delta_chunks)
844
if stored_bytes[0] == 'f':
845
fulltext_len, offset = decode_base128_int(stored_bytes[1:10])
846
data_len = fulltext_len + 1 + offset
847
if data_len != len(stored_bytes):
848
raise ValueError('Index claimed fulltext len, but stored bytes'
850
% (len(stored_bytes), data_len))
851
bytes = stored_bytes[offset + 1:]
853
# XXX: This is inefficient at best
854
source = ''.join(self.chunks[:start_chunk])
855
if stored_bytes[0] != 'd':
856
raise ValueError('Unknown content kind, bytes claim %s'
857
% (stored_bytes[0],))
858
delta_len, offset = decode_base128_int(stored_bytes[1:10])
859
data_len = delta_len + 1 + offset
860
if data_len != len(stored_bytes):
861
raise ValueError('Index claimed delta len, but stored bytes'
863
% (len(stored_bytes), data_len))
864
bytes = apply_delta(source, stored_bytes[offset + 1:])
865
bytes_sha1 = osutils.sha_string(bytes)
866
return bytes, bytes_sha1
869
"""Finish this group, creating a formatted stream.
871
After calling this, the compressor should no longer be used
873
# TODO: this causes us to 'bloat' to 2x the size of content in the
874
# group. This has an impact for 'commit' of large objects.
875
# One possibility is to use self._content_chunks, and be lazy and
876
# only fill out self._content as a full string when we actually
877
# need it. That would at least drop the peak memory consumption
878
# for 'commit' down to ~1x the size of the largest file, at a
879
# cost of increased complexity within this code. 2x is still <<
880
# 3x the size of the largest file, so we are doing ok.
881
self._block.set_chunked_content(self.chunks, self.endpoint)
883
self._delta_index = None
887
"""Call this if you want to 'revoke' the last compression.
889
After this, the data structures will be rolled back, but you cannot do
892
self._delta_index = None
893
del self.chunks[self._last[0]:]
894
self.endpoint = self._last[1]
898
"""Return the overall compression ratio."""
899
return float(self.input_bytes) / float(self.endpoint)
902
class PythonGroupCompressor(_CommonGroupCompressor):
905
"""Create a GroupCompressor.
907
Used only if the pyrex version is not available.
909
super(PythonGroupCompressor, self).__init__()
910
self._delta_index = LinesDeltaIndex([])
911
# The actual content is managed by LinesDeltaIndex
912
self.chunks = self._delta_index.lines
914
def _compress(self, key, bytes, max_delta_size, soft=False):
915
"""see _CommonGroupCompressor._compress"""
916
input_len = len(bytes)
917
new_lines = osutils.split_lines(bytes)
918
out_lines, index_lines = self._delta_index.make_delta(
919
new_lines, bytes_length=input_len, soft=soft)
920
delta_length = sum(map(len, out_lines))
921
if delta_length > max_delta_size:
922
# The delta is longer than the fulltext, insert a fulltext
924
out_lines = ['f', encode_base128_int(input_len)]
925
out_lines.extend(new_lines)
926
index_lines = [False, False]
927
index_lines.extend([True] * len(new_lines))
929
# this is a worthy delta, output it
932
# Update the delta_length to include those two encoded integers
933
out_lines[1] = encode_base128_int(delta_length)
935
start = self.endpoint
936
chunk_start = len(self.chunks)
937
self._last = (chunk_start, self.endpoint)
938
self._delta_index.extend_lines(out_lines, index_lines)
939
self.endpoint = self._delta_index.endpoint
940
self.input_bytes += input_len
941
chunk_end = len(self.chunks)
942
self.labels_deltas[key] = (start, chunk_start,
943
self.endpoint, chunk_end)
944
return start, self.endpoint, type
947
class PyrexGroupCompressor(_CommonGroupCompressor):
948
"""Produce a serialised group of compressed texts.
950
It contains code very similar to SequenceMatcher because of having a similar
951
task. However some key differences apply:
952
- there is no junk, we want a minimal edit not a human readable diff.
953
- we don't filter very common lines (because we don't know where a good
954
range will start, and after the first text we want to be emitting minmal
956
- we chain the left side, not the right side
957
- we incrementally update the adjacency matrix as new lines are provided.
958
- we look for matches in all of the left side, so the routine which does
959
the analagous task of find_longest_match does not need to filter on the
964
super(PyrexGroupCompressor, self).__init__()
965
self._delta_index = DeltaIndex()
967
def _compress(self, key, bytes, max_delta_size, soft=False):
968
"""see _CommonGroupCompressor._compress"""
969
input_len = len(bytes)
970
# By having action/label/sha1/len, we can parse the group if the index
971
# was ever destroyed, we have the key in 'label', we know the final
972
# bytes are valid from sha1, and we know where to find the end of this
973
# record because of 'len'. (the delta record itself will store the
974
# total length for the expanded record)
975
# 'len: %d\n' costs approximately 1% increase in total data
976
# Having the labels at all costs us 9-10% increase, 38% increase for
977
# inventory pages, and 5.8% increase for text pages
978
# new_chunks = ['label:%s\nsha1:%s\n' % (label, sha1)]
979
if self._delta_index._source_offset != self.endpoint:
980
raise AssertionError('_source_offset != endpoint'
981
' somehow the DeltaIndex got out of sync with'
983
delta = self._delta_index.make_delta(bytes, max_delta_size)
986
enc_length = encode_base128_int(len(bytes))
987
len_mini_header = 1 + len(enc_length)
988
self._delta_index.add_source(bytes, len_mini_header)
989
new_chunks = ['f', enc_length, bytes]
992
enc_length = encode_base128_int(len(delta))
993
len_mini_header = 1 + len(enc_length)
994
new_chunks = ['d', enc_length, delta]
995
self._delta_index.add_delta_source(delta, len_mini_header)
997
start = self.endpoint
998
chunk_start = len(self.chunks)
999
# Now output these bytes
1000
self._output_chunks(new_chunks)
1001
self.input_bytes += input_len
1002
chunk_end = len(self.chunks)
1003
self.labels_deltas[key] = (start, chunk_start,
1004
self.endpoint, chunk_end)
1005
if not self._delta_index._source_offset == self.endpoint:
1006
raise AssertionError('the delta index is out of sync'
1007
'with the output lines %s != %s'
1008
% (self._delta_index._source_offset, self.endpoint))
1009
return start, self.endpoint, type
1011
def _output_chunks(self, new_chunks):
1012
"""Output some chunks.
1014
:param new_chunks: The chunks to output.
1016
self._last = (len(self.chunks), self.endpoint)
1017
endpoint = self.endpoint
1018
self.chunks.extend(new_chunks)
1019
endpoint += sum(map(len, new_chunks))
1020
self.endpoint = endpoint
1023
def make_pack_factory(graph, delta, keylength, inconsistency_fatal=True):
1024
"""Create a factory for creating a pack based groupcompress.
1026
This is only functional enough to run interface tests, it doesn't try to
1027
provide a full pack environment.
1029
:param graph: Store a graph.
1030
:param delta: Delta compress contents.
1031
:param keylength: How long should keys be.
1033
def factory(transport):
1038
graph_index = BTreeBuilder(reference_lists=ref_length,
1039
key_elements=keylength)
1040
stream = transport.open_write_stream('newpack')
1041
writer = pack.ContainerWriter(stream.write)
1043
index = _GCGraphIndex(graph_index, lambda:True, parents=parents,
1044
add_callback=graph_index.add_nodes,
1045
inconsistency_fatal=inconsistency_fatal)
1046
access = knit._DirectPackAccess({})
1047
access.set_writer(writer, graph_index, (transport, 'newpack'))
1048
result = GroupCompressVersionedFiles(index, access, delta)
1049
result.stream = stream
1050
result.writer = writer
1055
def cleanup_pack_group(versioned_files):
1056
versioned_files.writer.end()
1057
versioned_files.stream.close()
1060
class _BatchingBlockFetcher(object):
1061
"""Fetch group compress blocks in batches.
1063
:ivar total_bytes: int of expected number of bytes needed to fetch the
1064
currently pending batch.
1067
def __init__(self, gcvf, locations):
1069
self.locations = locations
1071
self.batch_memos = {}
1072
self.memos_to_get = []
1073
self.total_bytes = 0
1074
self.last_read_memo = None
1077
def add_key(self, key):
1078
"""Add another to key to fetch.
1080
:return: The estimated number of bytes needed to fetch the batch so
1083
self.keys.append(key)
1084
index_memo, _, _, _ = self.locations[key]
1085
read_memo = index_memo[0:3]
1086
# Three possibilities for this read_memo:
1087
# - it's already part of this batch; or
1088
# - it's not yet part of this batch, but is already cached; or
1089
# - it's not yet part of this batch and will need to be fetched.
1090
if read_memo in self.batch_memos:
1091
# This read memo is already in this batch.
1092
return self.total_bytes
1094
cached_block = self.gcvf._group_cache[read_memo]
1096
# This read memo is new to this batch, and the data isn't cached
1098
self.batch_memos[read_memo] = None
1099
self.memos_to_get.append(read_memo)
1100
byte_length = read_memo[2]
1101
self.total_bytes += byte_length
1103
# This read memo is new to this batch, but cached.
1104
# Keep a reference to the cached block in batch_memos because it's
1105
# certain that we'll use it when this batch is processed, but
1106
# there's a risk that it would fall out of _group_cache between now
1108
self.batch_memos[read_memo] = cached_block
1109
return self.total_bytes
1111
def _flush_manager(self):
1112
if self.manager is not None:
1113
for factory in self.manager.get_record_stream():
1116
self.last_read_memo = None
1118
def yield_factories(self, full_flush=False):
1119
"""Yield factories for keys added since the last yield. They will be
1120
returned in the order they were added via add_key.
1122
:param full_flush: by default, some results may not be returned in case
1123
they can be part of the next batch. If full_flush is True, then
1124
all results are returned.
1126
if self.manager is None and not self.keys:
1128
# Fetch all memos in this batch.
1129
blocks = self.gcvf._get_blocks(self.memos_to_get)
1130
# Turn blocks into factories and yield them.
1131
memos_to_get_stack = list(self.memos_to_get)
1132
memos_to_get_stack.reverse()
1133
for key in self.keys:
1134
index_memo, _, parents, _ = self.locations[key]
1135
read_memo = index_memo[:3]
1136
if self.last_read_memo != read_memo:
1137
# We are starting a new block. If we have a
1138
# manager, we have found everything that fits for
1139
# now, so yield records
1140
for factory in self._flush_manager():
1142
# Now start a new manager.
1143
if memos_to_get_stack and memos_to_get_stack[-1] == read_memo:
1144
# The next block from _get_blocks will be the block we
1146
block_read_memo, block = blocks.next()
1147
if block_read_memo != read_memo:
1148
raise AssertionError(
1149
"block_read_memo out of sync with read_memo"
1150
"(%r != %r)" % (block_read_memo, read_memo))
1151
self.batch_memos[read_memo] = block
1152
memos_to_get_stack.pop()
1154
block = self.batch_memos[read_memo]
1155
self.manager = _LazyGroupContentManager(block)
1156
self.last_read_memo = read_memo
1157
start, end = index_memo[3:5]
1158
self.manager.add_factory(key, parents, start, end)
1160
for factory in self._flush_manager():
1163
self.batch_memos.clear()
1164
del self.memos_to_get[:]
1165
self.total_bytes = 0
1168
class GroupCompressVersionedFiles(VersionedFiles):
1169
"""A group-compress based VersionedFiles implementation."""
1171
def __init__(self, index, access, delta=True):
1172
"""Create a GroupCompressVersionedFiles object.
1174
:param index: The index object storing access and graph data.
1175
:param access: The access object storing raw data.
1176
:param delta: Whether to delta compress or just entropy compress.
1179
self._access = access
1181
self._unadded_refs = {}
1182
self._group_cache = LRUSizeCache(max_size=50*1024*1024)
1183
self._fallback_vfs = []
1185
def add_lines(self, key, parents, lines, parent_texts=None,
1186
left_matching_blocks=None, nostore_sha=None, random_id=False,
1187
check_content=True):
1188
"""Add a text to the store.
1190
:param key: The key tuple of the text to add.
1191
:param parents: The parents key tuples of the text to add.
1192
:param lines: A list of lines. Each line must be a bytestring. And all
1193
of them except the last must be terminated with \n and contain no
1194
other \n's. The last line may either contain no \n's or a single
1195
terminating \n. If the lines list does meet this constraint the add
1196
routine may error or may succeed - but you will be unable to read
1197
the data back accurately. (Checking the lines have been split
1198
correctly is expensive and extremely unlikely to catch bugs so it
1199
is not done at runtime unless check_content is True.)
1200
:param parent_texts: An optional dictionary containing the opaque
1201
representations of some or all of the parents of version_id to
1202
allow delta optimisations. VERY IMPORTANT: the texts must be those
1203
returned by add_lines or data corruption can be caused.
1204
:param left_matching_blocks: a hint about which areas are common
1205
between the text and its left-hand-parent. The format is
1206
the SequenceMatcher.get_matching_blocks format.
1207
:param nostore_sha: Raise ExistingContent and do not add the lines to
1208
the versioned file if the digest of the lines matches this.
1209
:param random_id: If True a random id has been selected rather than
1210
an id determined by some deterministic process such as a converter
1211
from a foreign VCS. When True the backend may choose not to check
1212
for uniqueness of the resulting key within the versioned file, so
1213
this should only be done when the result is expected to be unique
1215
:param check_content: If True, the lines supplied are verified to be
1216
bytestrings that are correctly formed lines.
1217
:return: The text sha1, the number of bytes in the text, and an opaque
1218
representation of the inserted version which can be provided
1219
back to future add_lines calls in the parent_texts dictionary.
1221
self._index._check_write_ok()
1222
self._check_add(key, lines, random_id, check_content)
1224
# The caller might pass None if there is no graph data, but kndx
1225
# indexes can't directly store that, so we give them
1226
# an empty tuple instead.
1228
# double handling for now. Make it work until then.
1229
length = sum(map(len, lines))
1230
record = ChunkedContentFactory(key, parents, None, lines)
1231
sha1 = list(self._insert_record_stream([record], random_id=random_id,
1232
nostore_sha=nostore_sha))[0]
1233
return sha1, length, None
1235
def _add_text(self, key, parents, text, nostore_sha=None, random_id=False):
1236
"""See VersionedFiles._add_text()."""
1237
self._index._check_write_ok()
1238
self._check_add(key, None, random_id, check_content=False)
1239
if text.__class__ is not str:
1240
raise errors.BzrBadParameterUnicode("text")
1242
# The caller might pass None if there is no graph data, but kndx
1243
# indexes can't directly store that, so we give them
1244
# an empty tuple instead.
1246
# double handling for now. Make it work until then.
1248
record = FulltextContentFactory(key, parents, None, text)
1249
sha1 = list(self._insert_record_stream([record], random_id=random_id,
1250
nostore_sha=nostore_sha))[0]
1251
return sha1, length, None
1253
def add_fallback_versioned_files(self, a_versioned_files):
1254
"""Add a source of texts for texts not present in this knit.
1256
:param a_versioned_files: A VersionedFiles object.
1258
self._fallback_vfs.append(a_versioned_files)
1260
def annotate(self, key):
1261
"""See VersionedFiles.annotate."""
1262
ann = annotate.Annotator(self)
1263
return ann.annotate_flat(key)
1265
def get_annotator(self):
1266
return annotate.Annotator(self)
1268
def check(self, progress_bar=None, keys=None):
1269
"""See VersionedFiles.check()."""
1272
for record in self.get_record_stream(keys, 'unordered', True):
1273
record.get_bytes_as('fulltext')
1275
return self.get_record_stream(keys, 'unordered', True)
1277
def _check_add(self, key, lines, random_id, check_content):
1278
"""check that version_id and lines are safe to add."""
1279
version_id = key[-1]
1280
if version_id is not None:
1281
if osutils.contains_whitespace(version_id):
1282
raise errors.InvalidRevisionId(version_id, self)
1283
self.check_not_reserved_id(version_id)
1284
# TODO: If random_id==False and the key is already present, we should
1285
# probably check that the existing content is identical to what is
1286
# being inserted, and otherwise raise an exception. This would make
1287
# the bundle code simpler.
1289
self._check_lines_not_unicode(lines)
1290
self._check_lines_are_lines(lines)
1292
def get_known_graph_ancestry(self, keys):
1293
"""Get a KnownGraph instance with the ancestry of keys."""
1294
# Note that this is identical to
1295
# KnitVersionedFiles.get_known_graph_ancestry, but they don't share
1297
parent_map, missing_keys = self._index.find_ancestry(keys)
1298
for fallback in self._fallback_vfs:
1299
if not missing_keys:
1301
(f_parent_map, f_missing_keys) = fallback._index.find_ancestry(
1303
parent_map.update(f_parent_map)
1304
missing_keys = f_missing_keys
1305
kg = _mod_graph.KnownGraph(parent_map)
1308
def get_parent_map(self, keys):
1309
"""Get a map of the graph parents of keys.
1311
:param keys: The keys to look up parents for.
1312
:return: A mapping from keys to parents. Absent keys are absent from
1315
return self._get_parent_map_with_sources(keys)[0]
1317
def _get_parent_map_with_sources(self, keys):
1318
"""Get a map of the parents of keys.
1320
:param keys: The keys to look up parents for.
1321
:return: A tuple. The first element is a mapping from keys to parents.
1322
Absent keys are absent from the mapping. The second element is a
1323
list with the locations each key was found in. The first element
1324
is the in-this-knit parents, the second the first fallback source,
1328
sources = [self._index] + self._fallback_vfs
1331
for source in sources:
1334
new_result = source.get_parent_map(missing)
1335
source_results.append(new_result)
1336
result.update(new_result)
1337
missing.difference_update(set(new_result))
1338
return result, source_results
1340
def _get_blocks(self, read_memos):
1341
"""Get GroupCompressBlocks for the given read_memos.
1343
:returns: a series of (read_memo, block) pairs, in the order they were
1347
for read_memo in read_memos:
1349
block = self._group_cache[read_memo]
1353
cached[read_memo] = block
1355
not_cached_seen = set()
1356
for read_memo in read_memos:
1357
if read_memo in cached:
1358
# Don't fetch what we already have
1360
if read_memo in not_cached_seen:
1361
# Don't try to fetch the same data twice
1363
not_cached.append(read_memo)
1364
not_cached_seen.add(read_memo)
1365
raw_records = self._access.get_raw_records(not_cached)
1366
for read_memo in read_memos:
1368
yield read_memo, cached[read_memo]
1370
# Read the block, and cache it.
1371
zdata = raw_records.next()
1372
block = GroupCompressBlock.from_bytes(zdata)
1373
self._group_cache[read_memo] = block
1374
cached[read_memo] = block
1375
yield read_memo, block
1377
def get_missing_compression_parent_keys(self):
1378
"""Return the keys of missing compression parents.
1380
Missing compression parents occur when a record stream was missing
1381
basis texts, or a index was scanned that had missing basis texts.
1383
# GroupCompress cannot currently reference texts that are not in the
1384
# group, so this is valid for now
1387
def get_record_stream(self, keys, ordering, include_delta_closure):
1388
"""Get a stream of records for keys.
1390
:param keys: The keys to include.
1391
:param ordering: Either 'unordered' or 'topological'. A topologically
1392
sorted stream has compression parents strictly before their
1394
:param include_delta_closure: If True then the closure across any
1395
compression parents will be included (in the opaque data).
1396
:return: An iterator of ContentFactory objects, each of which is only
1397
valid until the iterator is advanced.
1399
# keys might be a generator
1400
orig_keys = list(keys)
1404
if (not self._index.has_graph
1405
and ordering in ('topological', 'groupcompress')):
1406
# Cannot topological order when no graph has been stored.
1407
# but we allow 'as-requested' or 'unordered'
1408
ordering = 'unordered'
1410
remaining_keys = keys
1413
keys = set(remaining_keys)
1414
for content_factory in self._get_remaining_record_stream(keys,
1415
orig_keys, ordering, include_delta_closure):
1416
remaining_keys.discard(content_factory.key)
1417
yield content_factory
1419
except errors.RetryWithNewPacks, e:
1420
self._access.reload_or_raise(e)
1422
def _find_from_fallback(self, missing):
1423
"""Find whatever keys you can from the fallbacks.
1425
:param missing: A set of missing keys. This set will be mutated as keys
1426
are found from a fallback_vfs
1427
:return: (parent_map, key_to_source_map, source_results)
1428
parent_map the overall key => parent_keys
1429
key_to_source_map a dict from {key: source}
1430
source_results a list of (source: keys)
1433
key_to_source_map = {}
1435
for source in self._fallback_vfs:
1438
source_parents = source.get_parent_map(missing)
1439
parent_map.update(source_parents)
1440
source_parents = list(source_parents)
1441
source_results.append((source, source_parents))
1442
key_to_source_map.update((key, source) for key in source_parents)
1443
missing.difference_update(source_parents)
1444
return parent_map, key_to_source_map, source_results
1446
def _get_ordered_source_keys(self, ordering, parent_map, key_to_source_map):
1447
"""Get the (source, [keys]) list.
1449
The returned objects should be in the order defined by 'ordering',
1450
which can weave between different sources.
1451
:param ordering: Must be one of 'topological' or 'groupcompress'
1452
:return: List of [(source, [keys])] tuples, such that all keys are in
1453
the defined order, regardless of source.
1455
if ordering == 'topological':
1456
present_keys = topo_sort(parent_map)
1458
# ordering == 'groupcompress'
1459
# XXX: This only optimizes for the target ordering. We may need
1460
# to balance that with the time it takes to extract
1461
# ordering, by somehow grouping based on
1462
# locations[key][0:3]
1463
present_keys = sort_gc_optimal(parent_map)
1464
# Now group by source:
1466
current_source = None
1467
for key in present_keys:
1468
source = key_to_source_map.get(key, self)
1469
if source is not current_source:
1470
source_keys.append((source, []))
1471
current_source = source
1472
source_keys[-1][1].append(key)
1475
def _get_as_requested_source_keys(self, orig_keys, locations, unadded_keys,
1478
current_source = None
1479
for key in orig_keys:
1480
if key in locations or key in unadded_keys:
1482
elif key in key_to_source_map:
1483
source = key_to_source_map[key]
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_io_ordered_source_keys(self, locations, unadded_keys,
1495
# This is the group the bytes are stored in, followed by the
1496
# location in the group
1497
return locations[key][0]
1498
present_keys = sorted(locations.iterkeys(), key=get_group)
1499
# We don't have an ordering for keys in the in-memory object, but
1500
# lets process the in-memory ones first.
1501
present_keys = list(unadded_keys) + present_keys
1502
# Now grab all of the ones from other sources
1503
source_keys = [(self, present_keys)]
1504
source_keys.extend(source_result)
1507
def _get_remaining_record_stream(self, keys, orig_keys, ordering,
1508
include_delta_closure):
1509
"""Get a stream of records for keys.
1511
:param keys: The keys to include.
1512
:param ordering: one of 'unordered', 'topological', 'groupcompress' or
1514
:param include_delta_closure: If True then the closure across any
1515
compression parents will be included (in the opaque data).
1516
:return: An iterator of ContentFactory objects, each of which is only
1517
valid until the iterator is advanced.
1520
locations = self._index.get_build_details(keys)
1521
unadded_keys = set(self._unadded_refs).intersection(keys)
1522
missing = keys.difference(locations)
1523
missing.difference_update(unadded_keys)
1524
(fallback_parent_map, key_to_source_map,
1525
source_result) = self._find_from_fallback(missing)
1526
if ordering in ('topological', 'groupcompress'):
1527
# would be better to not globally sort initially but instead
1528
# start with one key, recurse to its oldest parent, then grab
1529
# everything in the same group, etc.
1530
parent_map = dict((key, details[2]) for key, details in
1531
locations.iteritems())
1532
for key in unadded_keys:
1533
parent_map[key] = self._unadded_refs[key]
1534
parent_map.update(fallback_parent_map)
1535
source_keys = self._get_ordered_source_keys(ordering, parent_map,
1537
elif ordering == 'as-requested':
1538
source_keys = self._get_as_requested_source_keys(orig_keys,
1539
locations, unadded_keys, key_to_source_map)
1541
# We want to yield the keys in a semi-optimal (read-wise) ordering.
1542
# Otherwise we thrash the _group_cache and destroy performance
1543
source_keys = self._get_io_ordered_source_keys(locations,
1544
unadded_keys, source_result)
1546
yield AbsentContentFactory(key)
1547
# Batch up as many keys as we can until either:
1548
# - we encounter an unadded ref, or
1549
# - we run out of keys, or
1550
# - the total bytes to retrieve for this batch > BATCH_SIZE
1551
batcher = _BatchingBlockFetcher(self, locations)
1552
for source, keys in source_keys:
1555
if key in self._unadded_refs:
1556
# Flush batch, then yield unadded ref from
1558
for factory in batcher.yield_factories(full_flush=True):
1560
bytes, sha1 = self._compressor.extract(key)
1561
parents = self._unadded_refs[key]
1562
yield FulltextContentFactory(key, parents, sha1, bytes)
1564
if batcher.add_key(key) > BATCH_SIZE:
1565
# Ok, this batch is big enough. Yield some results.
1566
for factory in batcher.yield_factories():
1569
for factory in batcher.yield_factories(full_flush=True):
1571
for record in source.get_record_stream(keys, ordering,
1572
include_delta_closure):
1574
for factory in batcher.yield_factories(full_flush=True):
1577
def get_sha1s(self, keys):
1578
"""See VersionedFiles.get_sha1s()."""
1580
for record in self.get_record_stream(keys, 'unordered', True):
1581
if record.sha1 != None:
1582
result[record.key] = record.sha1
1584
if record.storage_kind != 'absent':
1585
result[record.key] = osutils.sha_string(
1586
record.get_bytes_as('fulltext'))
1589
def insert_record_stream(self, stream):
1590
"""Insert a record stream into this container.
1592
:param stream: A stream of records to insert.
1594
:seealso VersionedFiles.get_record_stream:
1596
# XXX: Setting random_id=True makes
1597
# test_insert_record_stream_existing_keys fail for groupcompress and
1598
# groupcompress-nograph, this needs to be revisited while addressing
1599
# 'bzr branch' performance issues.
1600
for _ in self._insert_record_stream(stream, random_id=False):
1603
def _insert_record_stream(self, stream, random_id=False, nostore_sha=None,
1605
"""Internal core to insert a record stream into this container.
1607
This helper function has a different interface than insert_record_stream
1608
to allow add_lines to be minimal, but still return the needed data.
1610
:param stream: A stream of records to insert.
1611
:param nostore_sha: If the sha1 of a given text matches nostore_sha,
1612
raise ExistingContent, rather than committing the new text.
1613
:param reuse_blocks: If the source is streaming from
1614
groupcompress-blocks, just insert the blocks as-is, rather than
1615
expanding the texts and inserting again.
1616
:return: An iterator over the sha1 of the inserted records.
1617
:seealso insert_record_stream:
1621
def get_adapter(adapter_key):
1623
return adapters[adapter_key]
1625
adapter_factory = adapter_registry.get(adapter_key)
1626
adapter = adapter_factory(self)
1627
adapters[adapter_key] = adapter
1629
# This will go up to fulltexts for gc to gc fetching, which isn't
1631
self._compressor = GroupCompressor()
1632
self._unadded_refs = {}
1635
bytes = self._compressor.flush().to_bytes()
1636
index, start, length = self._access.add_raw_records(
1637
[(None, len(bytes))], bytes)[0]
1639
for key, reads, refs in keys_to_add:
1640
nodes.append((key, "%d %d %s" % (start, length, reads), refs))
1641
self._index.add_records(nodes, random_id=random_id)
1642
self._unadded_refs = {}
1644
self._compressor = GroupCompressor()
1647
max_fulltext_len = 0
1648
max_fulltext_prefix = None
1649
insert_manager = None
1652
# XXX: TODO: remove this, it is just for safety checking for now
1653
inserted_keys = set()
1654
reuse_this_block = reuse_blocks
1655
for record in stream:
1656
# Raise an error when a record is missing.
1657
if record.storage_kind == 'absent':
1658
raise errors.RevisionNotPresent(record.key, self)
1660
if record.key in inserted_keys:
1661
trace.note('Insert claimed random_id=True,'
1662
' but then inserted %r two times', record.key)
1664
inserted_keys.add(record.key)
1666
# If the reuse_blocks flag is set, check to see if we can just
1667
# copy a groupcompress block as-is.
1668
# We only check on the first record (groupcompress-block) not
1669
# on all of the (groupcompress-block-ref) entries.
1670
# The reuse_this_block flag is then kept for as long as
1671
if record.storage_kind == 'groupcompress-block':
1672
# Check to see if we really want to re-use this block
1673
insert_manager = record._manager
1674
reuse_this_block = insert_manager.check_is_well_utilized()
1676
reuse_this_block = False
1677
if reuse_this_block:
1678
# We still want to reuse this block
1679
if record.storage_kind == 'groupcompress-block':
1680
# Insert the raw block into the target repo
1681
insert_manager = record._manager
1682
bytes = record._manager._block.to_bytes()
1683
_, start, length = self._access.add_raw_records(
1684
[(None, len(bytes))], bytes)[0]
1687
block_length = length
1688
if record.storage_kind in ('groupcompress-block',
1689
'groupcompress-block-ref'):
1690
if insert_manager is None:
1691
raise AssertionError('No insert_manager set')
1692
if insert_manager is not record._manager:
1693
raise AssertionError('insert_manager does not match'
1694
' the current record, we cannot be positive'
1695
' that the appropriate content was inserted.'
1697
value = "%d %d %d %d" % (block_start, block_length,
1698
record._start, record._end)
1699
nodes = [(record.key, value, (record.parents,))]
1700
# TODO: Consider buffering up many nodes to be added, not
1701
# sure how much overhead this has, but we're seeing
1702
# ~23s / 120s in add_records calls
1703
self._index.add_records(nodes, random_id=random_id)
1706
bytes = record.get_bytes_as('fulltext')
1707
except errors.UnavailableRepresentation:
1708
adapter_key = record.storage_kind, 'fulltext'
1709
adapter = get_adapter(adapter_key)
1710
bytes = adapter.get_bytes(record)
1711
if len(record.key) > 1:
1712
prefix = record.key[0]
1713
soft = (prefix == last_prefix)
1717
if max_fulltext_len < len(bytes):
1718
max_fulltext_len = len(bytes)
1719
max_fulltext_prefix = prefix
1720
(found_sha1, start_point, end_point,
1721
type) = self._compressor.compress(record.key,
1722
bytes, record.sha1, soft=soft,
1723
nostore_sha=nostore_sha)
1724
# delta_ratio = float(len(bytes)) / (end_point - start_point)
1725
# Check if we want to continue to include that text
1726
if (prefix == max_fulltext_prefix
1727
and end_point < 2 * max_fulltext_len):
1728
# As long as we are on the same file_id, we will fill at least
1729
# 2 * max_fulltext_len
1730
start_new_block = False
1731
elif end_point > 4*1024*1024:
1732
start_new_block = True
1733
elif (prefix is not None and prefix != last_prefix
1734
and end_point > 2*1024*1024):
1735
start_new_block = True
1737
start_new_block = False
1738
last_prefix = prefix
1740
self._compressor.pop_last()
1742
max_fulltext_len = len(bytes)
1743
(found_sha1, start_point, end_point,
1744
type) = self._compressor.compress(record.key, bytes,
1746
if record.key[-1] is None:
1747
key = record.key[:-1] + ('sha1:' + found_sha1,)
1750
self._unadded_refs[key] = record.parents
1752
keys_to_add.append((key, '%d %d' % (start_point, end_point),
1754
if len(keys_to_add):
1756
self._compressor = None
1758
def iter_lines_added_or_present_in_keys(self, keys, pb=None):
1759
"""Iterate over the lines in the versioned files from keys.
1761
This may return lines from other keys. Each item the returned
1762
iterator yields is a tuple of a line and a text version that that line
1763
is present in (not introduced in).
1765
Ordering of results is in whatever order is most suitable for the
1766
underlying storage format.
1768
If a progress bar is supplied, it may be used to indicate progress.
1769
The caller is responsible for cleaning up progress bars (because this
1773
* Lines are normalised by the underlying store: they will all have \n
1775
* Lines are returned in arbitrary order.
1777
:return: An iterator over (line, key).
1781
# we don't care about inclusions, the caller cares.
1782
# but we need to setup a list of records to visit.
1783
# we need key, position, length
1784
for key_idx, record in enumerate(self.get_record_stream(keys,
1785
'unordered', True)):
1786
# XXX: todo - optimise to use less than full texts.
1789
pb.update('Walking content', key_idx, total)
1790
if record.storage_kind == 'absent':
1791
raise errors.RevisionNotPresent(key, self)
1792
lines = osutils.split_lines(record.get_bytes_as('fulltext'))
1796
pb.update('Walking content', total, total)
1799
"""See VersionedFiles.keys."""
1800
if 'evil' in debug.debug_flags:
1801
trace.mutter_callsite(2, "keys scales with size of history")
1802
sources = [self._index] + self._fallback_vfs
1804
for source in sources:
1805
result.update(source.keys())
1809
class _GCGraphIndex(object):
1810
"""Mapper from GroupCompressVersionedFiles needs into GraphIndex storage."""
1812
def __init__(self, graph_index, is_locked, parents=True,
1813
add_callback=None, track_external_parent_refs=False,
1814
inconsistency_fatal=True, track_new_keys=False):
1815
"""Construct a _GCGraphIndex on a graph_index.
1817
:param graph_index: An implementation of bzrlib.index.GraphIndex.
1818
:param is_locked: A callback, returns True if the index is locked and
1820
:param parents: If True, record knits parents, if not do not record
1822
:param add_callback: If not None, allow additions to the index and call
1823
this callback with a list of added GraphIndex nodes:
1824
[(node, value, node_refs), ...]
1825
:param track_external_parent_refs: As keys are added, keep track of the
1826
keys they reference, so that we can query get_missing_parents(),
1828
:param inconsistency_fatal: When asked to add records that are already
1829
present, and the details are inconsistent with the existing
1830
record, raise an exception instead of warning (and skipping the
1833
self._add_callback = add_callback
1834
self._graph_index = graph_index
1835
self._parents = parents
1836
self.has_graph = parents
1837
self._is_locked = is_locked
1838
self._inconsistency_fatal = inconsistency_fatal
1839
if track_external_parent_refs:
1840
self._key_dependencies = knit._KeyRefs(
1841
track_new_keys=track_new_keys)
1843
self._key_dependencies = None
1845
def add_records(self, records, random_id=False):
1846
"""Add multiple records to the index.
1848
This function does not insert data into the Immutable GraphIndex
1849
backing the KnitGraphIndex, instead it prepares data for insertion by
1850
the caller and checks that it is safe to insert then calls
1851
self._add_callback with the prepared GraphIndex nodes.
1853
:param records: a list of tuples:
1854
(key, options, access_memo, parents).
1855
:param random_id: If True the ids being added were randomly generated
1856
and no check for existence will be performed.
1858
if not self._add_callback:
1859
raise errors.ReadOnlyError(self)
1860
# we hope there are no repositories with inconsistent parentage
1865
for (key, value, refs) in records:
1866
if not self._parents:
1870
raise errors.KnitCorrupt(self,
1871
"attempt to add node with parents "
1872
"in parentless index.")
1875
keys[key] = (value, refs)
1878
present_nodes = self._get_entries(keys)
1879
for (index, key, value, node_refs) in present_nodes:
1880
if node_refs != keys[key][1]:
1881
details = '%s %s %s' % (key, (value, node_refs), keys[key])
1882
if self._inconsistency_fatal:
1883
raise errors.KnitCorrupt(self, "inconsistent details"
1884
" in add_records: %s" %
1887
trace.warning("inconsistent details in skipped"
1888
" record: %s", details)
1894
for key, (value, node_refs) in keys.iteritems():
1895
result.append((key, value, node_refs))
1897
for key, (value, node_refs) in keys.iteritems():
1898
result.append((key, value))
1900
key_dependencies = self._key_dependencies
1901
if key_dependencies is not None:
1903
for key, value, refs in records:
1905
key_dependencies.add_references(key, parents)
1907
for key, value, refs in records:
1908
new_keys.add_key(key)
1909
self._add_callback(records)
1911
def _check_read(self):
1912
"""Raise an exception if reads are not permitted."""
1913
if not self._is_locked():
1914
raise errors.ObjectNotLocked(self)
1916
def _check_write_ok(self):
1917
"""Raise an exception if writes are not permitted."""
1918
if not self._is_locked():
1919
raise errors.ObjectNotLocked(self)
1921
def _get_entries(self, keys, check_present=False):
1922
"""Get the entries for keys.
1924
Note: Callers are responsible for checking that the index is locked
1925
before calling this method.
1927
:param keys: An iterable of index key tuples.
1932
for node in self._graph_index.iter_entries(keys):
1934
found_keys.add(node[1])
1936
# adapt parentless index to the rest of the code.
1937
for node in self._graph_index.iter_entries(keys):
1938
yield node[0], node[1], node[2], ()
1939
found_keys.add(node[1])
1941
missing_keys = keys.difference(found_keys)
1943
raise errors.RevisionNotPresent(missing_keys.pop(), self)
1945
def find_ancestry(self, keys):
1946
"""See CombinedGraphIndex.find_ancestry"""
1947
return self._graph_index.find_ancestry(keys, 0)
1949
def get_parent_map(self, keys):
1950
"""Get a map of the parents of keys.
1952
:param keys: The keys to look up parents for.
1953
:return: A mapping from keys to parents. Absent keys are absent from
1957
nodes = self._get_entries(keys)
1961
result[node[1]] = node[3][0]
1964
result[node[1]] = None
1967
def get_missing_parents(self):
1968
"""Return the keys of missing parents."""
1969
# Copied from _KnitGraphIndex.get_missing_parents
1970
# We may have false positives, so filter those out.
1971
self._key_dependencies.satisfy_refs_for_keys(
1972
self.get_parent_map(self._key_dependencies.get_unsatisfied_refs()))
1973
return frozenset(self._key_dependencies.get_unsatisfied_refs())
1975
def get_build_details(self, keys):
1976
"""Get the various build details for keys.
1978
Ghosts are omitted from the result.
1980
:param keys: An iterable of keys.
1981
:return: A dict of key:
1982
(index_memo, compression_parent, parents, record_details).
1984
opaque structure to pass to read_records to extract the raw
1987
Content that this record is built upon, may be None
1989
Logical parents of this node
1991
extra information about the content which needs to be passed to
1992
Factory.parse_record
1996
entries = self._get_entries(keys)
1997
for entry in entries:
1999
if not self._parents:
2002
parents = entry[3][0]
2004
result[key] = (self._node_to_position(entry),
2005
None, parents, (method, None))
2009
"""Get all the keys in the collection.
2011
The keys are not ordered.
2014
return [node[1] for node in self._graph_index.iter_all_entries()]
2016
def _node_to_position(self, node):
2017
"""Convert an index value to position details."""
2018
bits = node[2].split(' ')
2019
# It would be nice not to read the entire gzip.
2020
start = int(bits[0])
2022
basis_end = int(bits[2])
2023
delta_end = int(bits[3])
2024
return node[0], start, stop, basis_end, delta_end
2026
def scan_unvalidated_index(self, graph_index):
2027
"""Inform this _GCGraphIndex that there is an unvalidated index.
2029
This allows this _GCGraphIndex to keep track of any missing
2030
compression parents we may want to have filled in to make those
2031
indices valid. It also allows _GCGraphIndex to track any new keys.
2033
:param graph_index: A GraphIndex
2035
key_dependencies = self._key_dependencies
2036
if key_dependencies is None:
2038
for node in graph_index.iter_all_entries():
2039
# Add parent refs from graph_index (and discard parent refs
2040
# that the graph_index has).
2041
key_dependencies.add_references(node[1], node[3][0])
2044
from bzrlib._groupcompress_py import (
2046
apply_delta_to_source,
2049
decode_copy_instruction,
2053
from bzrlib._groupcompress_pyx import (
2055
apply_delta_to_source,
2060
GroupCompressor = PyrexGroupCompressor
2062
GroupCompressor = PythonGroupCompressor
added
removed
bzrlib/groupcompress.py
