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devicehub-teal/ereuse_devicehub/resources/device/search.py

152 lines
6.3 KiB
Python

from itertools import chain
import inflection
from sqlalchemy.dialects import postgresql
from sqlalchemy.dialects.postgresql import TSVECTOR
from sqlalchemy.orm import aliased
from ereuse_devicehub.db import db
from ereuse_devicehub.resources import search
from ereuse_devicehub.resources.agent.models import Organization
from ereuse_devicehub.resources.device.models import Component, Computer, Device
from ereuse_devicehub.resources.event.models import Event, EventWithMultipleDevices, \
EventWithOneDevice
from ereuse_devicehub.resources.tag.model import Tag
class DeviceSearch(db.Model):
"""Temporary table that stores full-text device documents.
It provides methods to auto-run
"""
device_id = db.Column(db.BigInteger,
db.ForeignKey(Device.id, ondelete='CASCADE'),
primary_key=True)
device = db.relationship(Device, primaryjoin=Device.id == device_id)
properties = db.Column(TSVECTOR, nullable=False)
tags = db.Column(TSVECTOR)
__table_args__ = (
# todo to add concurrency this should be commited separately
# see https://docs.sqlalchemy.org/en/latest/dialects/postgresql.html#indexes-with-concurrently
db.Index('properties gist', properties, postgresql_using='gist'),
db.Index('tags gist', tags, postgresql_using='gist'),
{
'prefixes': ['UNLOGGED']
# Only for temporal tables, can cause table to empty on turn on
}
)
@classmethod
def update_modified_devices(cls, session: db.Session):
"""Updates the documents of the devices that are part of a
modified event, or tag in the passed-in session.
This method is registered as a SQLAlchemy listener in the
Devicehub class.
"""
devices_to_update = set()
for model in chain(session.new, session.dirty):
if isinstance(model, Event):
if isinstance(model, EventWithMultipleDevices):
devices_to_update |= model.devices
elif isinstance(model, EventWithOneDevice):
devices_to_update.add(model.device)
if model.parent:
devices_to_update.add(model.parent)
devices_to_update |= model.components
elif isinstance(model, Tag) and model.device:
devices_to_update.add(model.device)
# this flush is controversial:
# see https://groups.google.com/forum/#!topic/sqlalchemy/hBzfypgPfYo
# todo probably should replace it with what the solution says
session.flush()
for device in (d for d in devices_to_update if not isinstance(d, Component)):
cls.set_device_tokens(session, device)
@classmethod
def set_all_devices_tokens_if_empty(cls, session: db.Session):
"""Generates the search docs if the table is empty.
This can happen if Postgres' shut down unexpectedly, as
it deletes unlogged tables as ours.
"""
if not DeviceSearch.query.first():
cls.regenerate_search_table(session)
@classmethod
def regenerate_search_table(cls, session: db.Session):
"""Deletes and re-computes all the search table."""
DeviceSearch.query.delete()
for device in Device.query:
if not isinstance(device, Component):
cls.set_device_tokens(session, device)
@classmethod
def set_device_tokens(cls, session: db.Session, device: Device):
"""(Re)Generates the device search tokens."""
assert not isinstance(device, Component)
tokens = [
(str(device.id), search.Weight.A),
(inflection.humanize(device.type), search.Weight.B),
(Device.model, search.Weight.B),
(Device.manufacturer, search.Weight.C),
(Device.serial_number, search.Weight.A)
]
if device.manufacturer:
# todo this has to be done using a dictionary
manufacturer = device.manufacturer.lower()
if 'asus' in manufacturer:
tokens.append(('asus', search.Weight.B))
if 'hewlett' in manufacturer or 'hp' in manufacturer or 'h.p' in manufacturer:
tokens.append(('hp', search.Weight.B))
tokens.append(('h.p', search.Weight.C))
tokens.append(('hewlett', search.Weight.C))
tokens.append(('packard', search.Weight.C))
if isinstance(device, Computer):
# Aggregate the values of all the components of pc
Comp = aliased(Component)
tokens.extend((
(db.func.string_agg(db.cast(Comp.id, db.TEXT), ' '), search.Weight.D),
(db.func.string_agg(Comp.model, ' '), search.Weight.C),
(db.func.string_agg(Comp.manufacturer, ' '), search.Weight.D),
(db.func.string_agg(Comp.serial_number, ' '), search.Weight.B),
(db.func.string_agg(Comp.type, ' '), search.Weight.B),
('Computer', search.Weight.C),
('PC', search.Weight.C),
(inflection.humanize(device.chassis.name), search.Weight.B),
))
properties = session \
.query(search.Search.vectorize(*tokens)) \
.filter(Device.id == device.id)
if isinstance(device, Computer):
# Join to components
properties = properties \
.outerjoin(Comp, Computer.components) \
.group_by(Device.id)
tags = session.query(
search.Search.vectorize(
(db.func.string_agg(Tag.id, ' '), search.Weight.A),
(db.func.string_agg(Tag.secondary, ' '), search.Weight.A),
(db.func.string_agg(Organization.name, ' '), search.Weight.B)
)
).filter(Tag.device_id == device.id).join(Tag.org)
# Note that commit flushes later
# todo see how to get rid of the one_or_none() by embedding those as subqueries
# I don't like this but I want the 'on_conflict_on_update' thingie
device_document = dict(properties=properties.one_or_none(), tags=tags.one_or_none())
insert = postgresql.insert(DeviceSearch.__table__) \
.values(device_id=device.id, **device_document) \
.on_conflict_do_update(constraint='device_search_pkey', set_=device_document)
session.execute(insert)