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.action.models import Action, ActionWithMultipleDevices, \ ActionWithOneDevice from ereuse_devicehub.resources.agent.models import Organization from ereuse_devicehub.resources.device.models import Component, Computer, Device 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 action, 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, Action): if isinstance(model, ActionWithMultipleDevices): devices_to_update |= model.devices elif isinstance(model, ActionWithOneDevice): 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)