# Copyright (C) 2017-2021 The Software Heritage developers
# See the AUTHORS file at the top-level directory of this distribution
# License: GNU General Public License version 3, or any later version
# See top-level LICENSE file for more information
"""Storage backfiller.
The backfiller goal is to produce back part or all of the objects
from a storage to the journal topics
Current implementation consists in the JournalBackfiller class.
It simply reads the objects from the storage and sends every object identifier back to
the journal.
"""
import logging
from typing import Any, Callable, Dict, Iterable, Iterator, Optional, Tuple, Union
from swh.core.db import BaseDb
from swh.model.model import (
BaseModel,
Directory,
DirectoryEntry,
ExtID,
RawExtrinsicMetadata,
Release,
Revision,
Snapshot,
SnapshotBranch,
TargetType,
)
from swh.model.swhids import ExtendedObjectType
from swh.storage.postgresql.converters import (
db_to_extid,
db_to_raw_extrinsic_metadata,
db_to_release,
db_to_revision,
)
from swh.storage.replay import OBJECT_CONVERTERS
from swh.storage.writer import JournalWriter
logger = logging.getLogger(__name__)
PARTITION_KEY = {
"content": "sha1",
"skipped_content": "sha1",
"directory": "id",
"extid": "target",
"metadata_authority": "type, url",
"metadata_fetcher": "name, version",
"raw_extrinsic_metadata": "target",
"revision": "revision.id",
"release": "release.id",
"snapshot": "id",
"origin": "id",
"origin_visit": "origin_visit.origin",
"origin_visit_status": "origin_visit_status.origin",
}
COLUMNS = {
"content": [
"sha1",
"sha1_git",
"sha256",
"blake2s256",
"length",
"status",
"ctime",
],
"skipped_content": [
"sha1",
"sha1_git",
"sha256",
"blake2s256",
"length",
"ctime",
"status",
"reason",
],
"directory": ["id", "dir_entries", "file_entries", "rev_entries", "raw_manifest"],
"extid": ["extid_type", "extid", "extid_version", "target_type", "target"],
"metadata_authority": ["type", "url"],
"metadata_fetcher": ["name", "version"],
"origin": ["url"],
"origin_visit": [
"visit",
"type",
("origin.url", "origin"),
"date",
],
"origin_visit_status": [
("origin_visit_status.visit", "visit"),
("origin.url", "origin"),
("origin_visit_status.date", "date"),
"type",
"snapshot",
"status",
"metadata",
],
"raw_extrinsic_metadata": [
"raw_extrinsic_metadata.type",
"raw_extrinsic_metadata.target",
"metadata_authority.type",
"metadata_authority.url",
"metadata_fetcher.name",
"metadata_fetcher.version",
"discovery_date",
"format",
"raw_extrinsic_metadata.metadata",
"origin",
"visit",
"snapshot",
"release",
"revision",
"path",
"directory",
],
"revision": [
("revision.id", "id"),
"date",
"date_offset_bytes",
"committer_date",
"committer_date_offset_bytes",
"type",
"directory",
"message",
"synthetic",
"metadata",
"extra_headers",
(
"array(select parent_id::bytea from revision_history rh "
"where rh.id = revision.id order by rh.parent_rank asc)",
"parents",
),
"raw_manifest",
("a.id", "author_id"),
("a.name", "author_name"),
("a.email", "author_email"),
("a.fullname", "author_fullname"),
("c.id", "committer_id"),
("c.name", "committer_name"),
("c.email", "committer_email"),
("c.fullname", "committer_fullname"),
],
"release": [
("release.id", "id"),
"date",
"date_offset_bytes",
"comment",
("release.name", "name"),
"synthetic",
"target",
"target_type",
("a.id", "author_id"),
("a.name", "author_name"),
("a.email", "author_email"),
("a.fullname", "author_fullname"),
"raw_manifest",
],
"snapshot": ["id", "object_id"],
}
JOINS = {
"release": ["person a on release.author=a.id"],
"revision": [
"person a on revision.author=a.id",
"person c on revision.committer=c.id",
],
"origin_visit": ["origin on origin_visit.origin=origin.id"],
"origin_visit_status": [
"origin on origin_visit_status.origin=origin.id",
],
"raw_extrinsic_metadata": [
"metadata_authority on "
"raw_extrinsic_metadata.authority_id=metadata_authority.id",
"metadata_fetcher on raw_extrinsic_metadata.fetcher_id=metadata_fetcher.id",
],
}
EXTRA_WHERE = {
# hack to force the right index usage on table extid
"extid": "target_type in ('revision', 'release', 'content', 'directory')"
}
[docs]
def directory_converter(db: BaseDb, directory_d: Dict[str, Any]) -> Directory:
"""Convert directory from the flat representation to swh model
compatible objects.
"""
columns = ["target", "name", "perms"]
query_template = """
select %(columns)s
from directory_entry_%(type)s
where id in %%s
"""
types = ["file", "dir", "rev"]
entries = []
with db.cursor() as cur:
for type in types:
ids = directory_d.pop("%s_entries" % type)
if not ids:
continue
query = query_template % {
"columns": ",".join(columns),
"type": type,
}
cur.execute(query, (tuple(ids),))
for row in cur:
entry_d = dict(zip(columns, row))
entry = DirectoryEntry(
name=entry_d["name"],
type=type,
target=entry_d["target"],
perms=entry_d["perms"],
)
entries.append(entry)
(is_corrupt, dir_) = Directory.from_possibly_duplicated_entries(
id=directory_d["id"],
entries=tuple(entries),
raw_manifest=directory_d["raw_manifest"],
)
if is_corrupt:
logger.info("%s has duplicated entries", dir_.swhid())
return dir_
[docs]
def extid_converter(db: BaseDb, extid: Dict[str, Any]) -> ExtID:
"""Convert an extid from the flat representation to swh model
compatible objects.
"""
return db_to_extid(extid)
[docs]
def revision_converter(db: BaseDb, revision_d: Dict[str, Any]) -> Revision:
"""Convert revision from the flat representation to swh model
compatible objects.
"""
return db_to_revision(revision_d)
[docs]
def release_converter(db: BaseDb, release_d: Dict[str, Any]) -> Release:
"""Convert release from the flat representation to swh model
compatible objects.
"""
return db_to_release(release_d)
[docs]
def snapshot_converter(db: BaseDb, snapshot_d: Dict[str, Any]) -> Snapshot:
"""Convert snapshot from the flat representation to swh model
compatible objects.
"""
columns = ["name", "target", "target_type"]
query = """
select %s
from snapshot_branches sbs
inner join snapshot_branch sb on sb.object_id=sbs.branch_id
where sbs.snapshot_id=%%s
""" % ", ".join(
columns
)
with db.cursor() as cur:
cur.execute(query, (snapshot_d["object_id"],))
branches = {}
for name, *row in cur:
branch_d = dict(zip(columns[1:], row))
if branch_d["target"] is not None and branch_d["target_type"] is not None:
branch: Optional[SnapshotBranch] = SnapshotBranch(
target=branch_d["target"],
target_type=TargetType(branch_d["target_type"]),
)
else:
branch = None
branches[name] = branch
return Snapshot(
id=snapshot_d["id"],
branches=branches,
)
CONVERTERS: Dict[str, Callable[[BaseDb, Dict[str, Any]], BaseModel]] = {
"directory": directory_converter,
"extid": extid_converter,
"raw_extrinsic_metadata": raw_extrinsic_metadata_converter,
"revision": revision_converter,
"release": release_converter,
"snapshot": snapshot_converter,
}
[docs]
def object_to_offset(object_id, numbits):
"""Compute the index of the range containing object id, when dividing
space into 2^numbits.
Args:
object_id (str): The hex representation of object_id
numbits (int): Number of bits in which we divide input space
Returns:
The index of the range containing object id
"""
q, r = divmod(numbits, 8)
length = q + (r != 0)
shift_bits = 8 - r if r else 0
truncated_id = object_id[: length * 2]
if len(truncated_id) < length * 2:
truncated_id += "0" * (length * 2 - len(truncated_id))
truncated_id_bytes = bytes.fromhex(truncated_id)
return int.from_bytes(truncated_id_bytes, byteorder="big") >> shift_bits
[docs]
def byte_ranges(
numbits: int, start_object: Optional[str] = None, end_object: Optional[str] = None
) -> Iterator[Tuple[Optional[bytes], Optional[bytes]]]:
"""Generate start/end pairs of bytes spanning numbits bits and
constrained by optional start_object and end_object.
Args:
numbits: Number of bits in which we divide input space
start_object: Hex object id contained in the first range
returned
end_object: Hex object id contained in the last range
returned
Yields:
2^numbits pairs of bytes
"""
q, r = divmod(numbits, 8)
length = q + (r != 0)
shift_bits = 8 - r if r else 0
def to_bytes(i):
return int.to_bytes(i << shift_bits, length=length, byteorder="big")
start_offset = 0
end_offset = 1 << numbits
if start_object is not None:
start_offset = object_to_offset(start_object, numbits)
if end_object is not None:
end_offset = object_to_offset(end_object, numbits) + 1
for start in range(start_offset, end_offset):
end = start + 1
if start == 0:
yield None, to_bytes(end)
elif end == 1 << numbits:
yield to_bytes(start), None
else:
yield to_bytes(start), to_bytes(end)
[docs]
def integer_ranges(
start: str, end: str, block_size: int = 1000
) -> Iterator[Tuple[Optional[int], Optional[int]]]:
for range_start in range(int(start), int(end), block_size):
if range_start == 0:
yield None, block_size
elif range_start + block_size > int(end):
yield range_start, int(end)
else:
yield range_start, range_start + block_size
RANGE_GENERATORS: Dict[
str,
Union[
Callable[[str, str], Iterable[Tuple[Optional[str], Optional[str]]]],
Callable[[str, str], Iterable[Tuple[Optional[bytes], Optional[bytes]]]],
Callable[[str, str], Iterable[Tuple[Optional[int], Optional[int]]]],
],
] = {
"content": lambda start, end: byte_ranges(24, start, end),
"skipped_content": lambda start, end: [(None, None)],
"directory": lambda start, end: byte_ranges(24, start, end),
"extid": lambda start, end: byte_ranges(24, start, end),
"revision": lambda start, end: byte_ranges(24, start, end),
"release": lambda start, end: byte_ranges(16, start, end),
"raw_extrinsic_metadata": raw_extrinsic_metadata_target_ranges,
"snapshot": lambda start, end: byte_ranges(16, start, end),
"origin": integer_ranges,
"origin_visit": integer_ranges,
"origin_visit_status": integer_ranges,
}
[docs]
def compute_query(obj_type, start, end):
columns = COLUMNS.get(obj_type)
join_specs = JOINS.get(obj_type, [])
join_clause = "\n".join("left join %s" % clause for clause in join_specs)
additional_where = EXTRA_WHERE.get(obj_type)
where = []
where_args = []
if start:
where.append("%(keys)s >= %%s")
where_args.append(start)
if end:
where.append("%(keys)s < %%s")
where_args.append(end)
if additional_where:
where.append(additional_where)
where_clause = ""
if where:
where_clause = ("where " + " and ".join(where)) % {
"keys": "(%s)" % PARTITION_KEY[obj_type]
}
column_specs = []
column_aliases = []
for column in columns:
if isinstance(column, str):
column_specs.append(column)
column_aliases.append(column)
else:
column_specs.append("%s as %s" % column)
column_aliases.append(column[1])
query = """
select %(columns)s
from %(table)s
%(join)s
%(where)s
""" % {
"columns": ",".join(column_specs),
"table": obj_type,
"join": join_clause,
"where": where_clause,
}
return query, where_args, column_aliases
[docs]
def fetch(db, obj_type, start, end):
"""Fetch all obj_type's identifiers from db.
This opens one connection, stream objects and when done, close
the connection.
Args:
db (BaseDb): Db connection object
obj_type (str): Object type
start (Union[bytes|Tuple]): Range start identifier
end (Union[bytes|Tuple]): Range end identifier
Raises:
ValueError if obj_type is not supported
Yields:
Objects in the given range
"""
query, where_args, column_aliases = compute_query(obj_type, start, end)
converter = CONVERTERS.get(obj_type)
with db.cursor() as cursor:
logger.debug("Fetching data for table %s", obj_type)
logger.debug("query: %s %s", query, where_args)
cursor.execute(query, where_args)
for row in cursor:
record = dict(zip(column_aliases, row))
if converter:
record = converter(db, record)
else:
record = OBJECT_CONVERTERS[obj_type](record)
logger.debug("record: %s", record)
yield record
def _format_range_bound(bound):
if isinstance(bound, bytes):
return bound.hex()
else:
return str(bound)
MANDATORY_KEYS = ["storage", "journal_writer"]
[docs]
class JournalBackfiller:
"""Class in charge of reading the storage's objects and sends those
back to the journal's topics.
This is designed to be run periodically.
"""
def __init__(self, config=None):
self.config = config
self.check_config(config)
self._db = None
self.writer = JournalWriter({"cls": "kafka", **self.config["journal_writer"]})
assert self.writer.journal is not None
@property
def db(self):
if self._db is None:
self._db = BaseDb.connect(self.config["storage"]["db"])
return self._db
[docs]
def check_config(self, config):
missing_keys = []
for key in MANDATORY_KEYS:
if not config.get(key):
missing_keys.append(key)
if missing_keys:
raise ValueError(
"Configuration error: The following keys must be"
" provided: %s" % (",".join(missing_keys),)
)
if "cls" not in config["storage"] or config["storage"]["cls"] not in (
"local",
"postgresql",
):
raise ValueError(
"swh storage backfiller must be configured to use a local"
" (PostgreSQL) storage"
)
[docs]
def parse_arguments(self, object_type, start_object, end_object):
"""Parse arguments
Raises:
ValueError for unsupported object type
ValueError if object ids are not parseable
Returns:
Parsed start and end object ids
"""
if object_type not in COLUMNS:
raise ValueError(
"Object type %s is not supported. "
"The only possible values are %s"
% (object_type, ", ".join(sorted(COLUMNS.keys())))
)
if object_type in ["origin", "origin_visit", "origin_visit_status"]:
start_object = start_object or "0"
end_object = end_object or str(100_000_000) # hard-coded limit
return start_object, end_object
[docs]
def run(self, object_type, start_object, end_object, dry_run=False):
"""Reads storage's subscribed object types and send them to the
journal's reading topic.
"""
start_object, end_object = self.parse_arguments(
object_type, start_object, end_object
)
for range_start, range_end in RANGE_GENERATORS[object_type](
start_object, end_object
):
logger.info(
"Processing %s range %s to %s",
object_type,
_format_range_bound(range_start),
_format_range_bound(range_end),
)
objects = fetch(self.db, object_type, start=range_start, end=range_end)
if not dry_run:
self.writer.write_additions(object_type, objects)
else:
# only consume the objects iterator to check for any potential
# decoding/encoding errors
for obj in objects:
pass
if __name__ == "__main__":
print('Please use the "swh-journal backfiller run" command')
