ArchiveBox/archivebox/abid_utils/abid.py
2024-09-05 03:36:18 -07:00

223 lines
6.9 KiB
Python

__package__ = 'archivebox.abid_utils'
from typing import NamedTuple, Any, Union, Optional, Dict
import ulid
import uuid6
import hashlib
from urllib.parse import urlparse
from uuid import UUID
from typeid import TypeID # type: ignore[import-untyped]
from datetime import datetime
from ..util import enforce_types
ABID_PREFIX_LEN = 4
ABID_SUFFIX_LEN = 26
ABID_LEN = 30
ABID_TS_LEN = 10
ABID_URI_LEN = 8
ABID_SUBTYPE_LEN = 2
ABID_RAND_LEN = 6
DEFAULT_ABID_PREFIX = 'obj_'
# allows people to keep their uris secret on a per-instance basis by changing the salt.
# the default means everyone can share the same namespace for URI hashes,
# meaning anyone who has a URI and wants to check if you have it can guess the ABID
DEFAULT_ABID_URI_SALT = '687c2fff14e3a7780faa5a40c237b19b5b51b089'
class ABID(NamedTuple):
"""
e.g. ABID('obj_01HX9FPYTRE4A5CCD901ZYEBQE')
"""
prefix: str # e.g. obj_
ts: str # e.g. 01HX9FPYTR
uri: str # e.g. E4A5CCD9
subtype: str # e.g. 01
rand: str # e.g. ZYEBQE
# salt: str = DEFAULT_ABID_URI_SALT
def __getattr__(self, attr: str) -> Any:
return getattr(self.ulid, attr)
def __eq__(self, other: Any) -> bool:
try:
return self.ulid == other.ulid
except AttributeError:
return NotImplemented
def __str__(self) -> str:
return self.prefix + self.suffix
def __len__(self) -> int:
return len(self.prefix + self.suffix)
@classmethod
def parse(cls, buffer: Union[str, UUID, ulid.ULID, TypeID, 'ABID'], prefix=DEFAULT_ABID_PREFIX) -> 'ABID':
assert buffer, f'Attempted to create ABID from null value {buffer}'
buffer = str(buffer)
if '_' in buffer:
prefix, suffix = buffer.split('_')
else:
prefix, suffix = prefix.strip('_'), buffer
assert len(prefix) == ABID_PREFIX_LEN - 1 # length without trailing _
assert len(suffix) == ABID_SUFFIX_LEN, f'Suffix {suffix} from {buffer} was not {ABID_SUFFIX_LEN} chars long'
return cls(
prefix=abid_part_from_prefix(prefix),
ts=suffix[0:10].upper(),
uri=suffix[10:18].upper(),
subtype=suffix[18:20].upper(),
rand=suffix[20:26].upper(),
)
@property
def uri_salt(self) -> str:
return DEFAULT_ABID_URI_SALT
@property
def suffix(self):
return ''.join((self.ts, self.uri, self.subtype, self.rand))
@property
def ulid(self) -> ulid.ULID:
return ulid.parse(self.suffix)
@property
def uuid(self) -> UUID:
return self.ulid.uuid
@property
def uuid6(self) -> uuid6.UUID:
return uuid6.UUID(hex=self.uuid.hex)
@property
def typeid(self) -> TypeID:
return TypeID.from_uuid(prefix=self.prefix.strip('_'), suffix=self.uuid6)
@property
def datetime(self) -> datetime:
return self.ulid.timestamp().datetime
####################################################
@enforce_types
def uri_hash(uri: Union[str, bytes], salt: str=DEFAULT_ABID_URI_SALT) -> str:
"""
https://example.com -> 'E4A5CCD9AF4ED2A6E0954DF19FD274E9CDDB4853051F033FD518BFC90AA1AC25' (example.com)
"""
if isinstance(uri, bytes):
uri_str: str = uri.decode()
else:
uri_str = str(uri)
# only hash the domain part of URLs
if '://' in uri_str:
try:
domain = urlparse(uri_str).netloc
if domain:
uri_str = domain
except AttributeError:
pass
# the uri hash is the sha256 of the domain + salt
uri_bytes = uri_str.encode('utf-8') + salt.encode('utf-8')
return hashlib.sha256(uri_bytes).hexdigest().upper()
@enforce_types
def abid_part_from_prefix(prefix: str) -> str:
"""
'snp_'
"""
# if prefix is None:
# return 'obj_'
prefix = prefix.strip('_').lower()
assert len(prefix) == 3
return prefix + '_'
@enforce_types
def abid_part_from_uri(uri: Any, salt: str=DEFAULT_ABID_URI_SALT) -> str:
"""
'E4A5CCD9' # takes first 8 characters of sha256(url)
"""
uri = str(uri).strip()
assert uri not in ('None', '')
return uri_hash(uri, salt=salt)[:ABID_URI_LEN]
@enforce_types
def abid_part_from_ts(ts: datetime) -> str:
"""
'01HX9FPYTR' # produces 10 character Timestamp section of ulid based on added date
"""
return str(ulid.from_timestamp(ts))[:ABID_TS_LEN]
@enforce_types
def ts_from_abid(abid: str) -> datetime:
return ulid.parse(abid.split('_', 1)[-1]).timestamp().datetime
@enforce_types
def abid_part_from_subtype(subtype: str | int) -> str:
"""
Snapshots have 01 type, other objects have other subtypes like wget/media/etc.
Also allows us to change the ulid spec later by putting special sigil values here.
"""
subtype = str(subtype)
if len(subtype) == ABID_SUBTYPE_LEN:
return subtype
return hashlib.sha256(subtype.encode('utf-8')).hexdigest()[:ABID_SUBTYPE_LEN].upper()
@enforce_types
def abid_part_from_rand(rand: Union[str, UUID, None, int]) -> str:
"""
'ZYEBQE' # takes last 6 characters of randomness from existing legacy uuid db field
"""
if rand is None:
# if it's None we generate a new random 6 character hex string
return str(ulid.new())[-ABID_RAND_LEN:]
elif isinstance(rand, UUID):
# if it's a uuid we take the last 6 characters of the ULID represation of it
return str(ulid.from_uuid(rand))[-ABID_RAND_LEN:]
elif isinstance(rand, int):
# if it's a BigAutoInteger field we convert it from an int to a 0-padded string
rand_str = str(rand)[-ABID_RAND_LEN:]
padding_needed = ABID_RAND_LEN - len(rand_str)
rand_str = ('0'*padding_needed) + rand_str
return rand_str
# otherwise treat it as a string, take the last 6 characters of it verbatim
return str(rand)[-ABID_RAND_LEN:].upper()
@enforce_types
def abid_hashes_from_values(prefix: str, ts: datetime, uri: Any, subtype: str | int, rand: Union[str, UUID, None, int], salt: str=DEFAULT_ABID_URI_SALT) -> Dict[str, str]:
return {
'prefix': abid_part_from_prefix(prefix),
'ts': abid_part_from_ts(ts),
'uri': abid_part_from_uri(uri, salt=salt),
'subtype': abid_part_from_subtype(subtype),
'rand': abid_part_from_rand(rand),
# 'salt': don't add this, salt combined with uri above to form a single hash
}
@enforce_types
def abid_from_values(prefix: str, ts: datetime, uri: str, subtype: str, rand: Union[str, UUID, None, int], salt: str=DEFAULT_ABID_URI_SALT) -> ABID:
"""
Return a freshly derived ABID (assembled from attrs defined in ABIDModel.abid_*_src).
"""
abid = ABID(**abid_hashes_from_values(prefix, ts, uri, subtype, rand, salt=salt))
assert abid.ulid and abid.uuid and abid.typeid, f'Failed to calculate {prefix}_ABID for ts={ts} uri={uri} subtyp={subtype} rand={rand}'
return abid