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Differential D11934

changelog-v2: use helper constant in the code to pack/unpack entries
ClosedPublic

Authored by marmoute on Dec 16 2021, 12:43 PM.

Details

Reviewers
Alphare
Group Reviewers
hg-reviewers
Commits
rHG2c6084f67a86: changelog-v2: use helper constant in the code to pack/unpack entries
Summary

This makes the code simpler to read and modify. This is probably less
efficient, but we are talking about the Python implementation here, so
performance is concerne secondary to readability.

Diff Detail

Repository
rHG Mercurial
Lint
Automatic diff as part of commit; lint not applicable.
Unit
Automatic diff as part of commit; unit tests not applicable.

Revision Contents
Changeset List

Diff 31531

mercurial/pure/parsers.py

raise error.ProgrammingError(msg) raise error.ProgrammingError(msg)
class IndexChangelogV2(IndexObject2): class IndexChangelogV2(IndexObject2):
index_format = revlog_constants.INDEX_ENTRY_CL_V2 index_format = revlog_constants.INDEX_ENTRY_CL_V2
def _unpack_entry(self, rev, data, r=True): def _unpack_entry(self, rev, data, r=True):
items = self.index_format.unpack(data) items = self.index_format.unpack(data)
entry = items[:3] + (rev, rev) + items[3:8] return (
data_comp = items[8] & 3 items[revlog_constants.INDEX_ENTRY_V2_IDX_OFFSET],
sidedata_comp = (items[8] >> 2) & 3 items[revlog_constants.INDEX_ENTRY_V2_IDX_COMPRESSED_LENGTH],
return entry + (data_comp, sidedata_comp) items[revlog_constants.INDEX_ENTRY_V2_IDX_UNCOMPRESSED_LENGTH],
rev,
rev,
items[revlog_constants.INDEX_ENTRY_V2_IDX_PARENT_1],
items[revlog_constants.INDEX_ENTRY_V2_IDX_PARENT_2],
items[revlog_constants.INDEX_ENTRY_V2_IDX_NODEID],
items[revlog_constants.INDEX_ENTRY_V2_IDX_SIDEDATA_OFFSET],
items[
revlog_constants.INDEX_ENTRY_V2_IDX_SIDEDATA_COMPRESSED_LENGTH
],
items[revlog_constants.INDEX_ENTRY_V2_IDX_COMPRESSION_MODE] & 3,
(items[revlog_constants.INDEX_ENTRY_V2_IDX_COMPRESSION_MODE] >> 2)
& 3,
)
def _pack_entry(self, rev, entry): def _pack_entry(self, rev, entry):
assert entry[3] == rev, entry[3]
assert entry[4] == rev, entry[4] base = entry[revlog_constants.ENTRY_DELTA_BASE]
data = entry[:3] + entry[5:10] link_rev = entry[revlog_constants.ENTRY_LINK_REV]
data_comp = entry[10] & 3 assert base == rev, (base, rev)
sidedata_comp = (entry[11] & 3) << 2 assert link_rev == rev, (link_rev, rev)
data += (data_comp | sidedata_comp,) data = (
entry[revlog_constants.ENTRY_DATA_OFFSET],
entry[revlog_constants.ENTRY_DATA_COMPRESSED_LENGTH],
entry[revlog_constants.ENTRY_DATA_UNCOMPRESSED_LENGTH],
entry[revlog_constants.ENTRY_PARENT_1],
entry[revlog_constants.ENTRY_PARENT_2],
entry[revlog_constants.ENTRY_NODE_ID],
entry[revlog_constants.ENTRY_SIDEDATA_OFFSET],
entry[revlog_constants.ENTRY_SIDEDATA_COMPRESSED_LENGTH],
entry[revlog_constants.ENTRY_DATA_COMPRESSION_MODE] & 3
| (entry[revlog_constants.ENTRY_SIDEDATA_COMPRESSION_MODE] & 3)
<< 2,
)
return self.index_format.pack(*data) return self.index_format.pack(*data)
def parse_index_devel_nodemap(data, inline): def parse_index_devel_nodemap(data, inline):
"""like parse_index2, but alway return a PersistentNodeMapIndexObject""" """like parse_index2, but alway return a PersistentNodeMapIndexObject"""
return PersistentNodeMapIndexObject(data), None return PersistentNodeMapIndexObject(data), None

mercurial/revlogutils/constants.py

# 4 bytes: parent 2 rev # 4 bytes: parent 2 rev
# 32 bytes: nodeid # 32 bytes: nodeid
# 8 bytes: sidedata offset # 8 bytes: sidedata offset
# 4 bytes: sidedata compressed length # 4 bytes: sidedata compressed length
# 1 bytes: compression mode (2 lower bit are data_compression_mode) # 1 bytes: compression mode (2 lower bit are data_compression_mode)
# 27 bytes: Padding to align to 96 bytes (see RevlogV2Plan wiki page) # 27 bytes: Padding to align to 96 bytes (see RevlogV2Plan wiki page)
INDEX_ENTRY_CL_V2 = struct.Struct(b">Qiiii20s12xQiB27x") INDEX_ENTRY_CL_V2 = struct.Struct(b">Qiiii20s12xQiB27x")
assert INDEX_ENTRY_CL_V2.size == 32 * 3, INDEX_ENTRY_V2.size assert INDEX_ENTRY_CL_V2.size == 32 * 3, INDEX_ENTRY_V2.size
INDEX_ENTRY_V2_IDX_OFFSET = 0
INDEX_ENTRY_V2_IDX_COMPRESSED_LENGTH = 1
INDEX_ENTRY_V2_IDX_UNCOMPRESSED_LENGTH = 2
INDEX_ENTRY_V2_IDX_PARENT_1 = 3
INDEX_ENTRY_V2_IDX_PARENT_2 = 4
INDEX_ENTRY_V2_IDX_NODEID = 5
INDEX_ENTRY_V2_IDX_SIDEDATA_OFFSET = 6
INDEX_ENTRY_V2_IDX_SIDEDATA_COMPRESSED_LENGTH = 7
INDEX_ENTRY_V2_IDX_COMPRESSION_MODE = 8
# revlog index flags # revlog index flags
# For historical reasons, revlog's internal flags were exposed via the # For historical reasons, revlog's internal flags were exposed via the
# wire protocol and are even exposed in parts of the storage APIs. # wire protocol and are even exposed in parts of the storage APIs.
# revision has censor metadata, must be verified # revision has censor metadata, must be verified
REVIDX_ISCENSORED = repository.REVISION_FLAG_CENSORED REVIDX_ISCENSORED = repository.REVISION_FLAG_CENSORED