mirror of
https://github.com/Infinidat/infi.clickhouse_orm.git
synced 2025-10-29 14:57:27 +03:00
120 lines
4.6 KiB
Python
120 lines
4.6 KiB
Python
import requests
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from collections import namedtuple
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from models import ModelBase
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from utils import escape, parse_tsv, import_submodules
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from math import ceil
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import datetime
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import logging
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Page = namedtuple('Page', 'objects number_of_objects pages_total number page_size')
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class DatabaseException(Exception):
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pass
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class Database(object):
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def __init__(self, db_name, db_url='http://localhost:8123/', username=None, password=None):
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self.db_name = db_name
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self.db_url = db_url
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self.username = username
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self.password = password
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self._send('CREATE DATABASE IF NOT EXISTS `%s`' % db_name)
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def create_table(self, model_class):
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# TODO check that model has an engine
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self._send(model_class.create_table_sql(self.db_name))
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def drop_table(self, model_class):
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self._send(model_class.drop_table_sql(self.db_name))
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def drop_database(self):
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self._send('DROP DATABASE `%s`' % self.db_name)
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def insert(self, model_instances):
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i = iter(model_instances)
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try:
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first_instance = i.next()
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except StopIteration:
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return # model_instances is empty
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model_class = first_instance.__class__
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def gen():
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yield 'INSERT INTO `%s`.`%s` FORMAT TabSeparated\n' % (self.db_name, model_class.table_name())
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yield first_instance.to_tsv()
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yield '\n'
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for instance in i:
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yield instance.to_tsv()
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yield '\n'
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self._send(gen())
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def count(self, model_class, conditions=None):
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query = 'SELECT count() FROM `%s`.`%s`' % (self.db_name, model_class.table_name())
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if conditions:
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query += ' WHERE ' + conditions
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r = self._send(query)
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return int(r.text) if r.text else 0
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def select(self, query, model_class=None, settings=None):
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query += ' FORMAT TabSeparatedWithNamesAndTypes'
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r = self._send(query, settings)
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lines = r.iter_lines()
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field_names = parse_tsv(next(lines))
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field_types = parse_tsv(next(lines))
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model_class = model_class or ModelBase.create_ad_hoc_model(zip(field_names, field_types))
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for line in lines:
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yield model_class.from_tsv(line, field_names)
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def paginate(self, model_class, order_by, page_num=1, page_size=100, conditions=None, settings=None):
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count = self.count(model_class, conditions)
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pages_total = int(ceil(count / float(page_size)))
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offset = (page_num - 1) * page_size
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query = 'SELECT * FROM `%s`.`%s`' % (self.db_name, model_class.table_name())
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if conditions:
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query += ' WHERE ' + conditions
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query += ' ORDER BY %s' % order_by
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query += ' LIMIT %d, %d' % (offset, page_size)
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return Page(
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objects=list(self.select(query, model_class, settings)),
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number_of_objects=count,
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pages_total=pages_total,
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number=page_num,
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page_size=page_size
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)
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def migrate(self, migrations_package_name, up_to=9999):
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from migrations import MigrationHistory
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logger = logging.getLogger('migrations')
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applied_migrations = self._get_applied_migrations(migrations_package_name)
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modules = import_submodules(migrations_package_name)
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unapplied_migrations = set(modules.keys()) - applied_migrations
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for name in sorted(unapplied_migrations):
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logger.info('Applying migration %s...', name)
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for operation in modules[name].operations:
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operation.apply(self)
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self.insert([MigrationHistory(package_name=migrations_package_name, module_name=name, applied=datetime.date.today())])
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if int(name[:4]) >= up_to:
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break
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def _get_applied_migrations(self, migrations_package_name):
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from migrations import MigrationHistory
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self.create_table(MigrationHistory)
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query = "SELECT module_name from `%s`.`%s` WHERE package_name = '%s'" % (self.db_name, MigrationHistory.table_name(), migrations_package_name)
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return set(obj.module_name for obj in self.select(query))
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def _send(self, data, settings=None):
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params = self._build_params(settings)
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r = requests.post(self.db_url, params=params, data=data, stream=True)
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if r.status_code != 200:
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raise DatabaseException(r.text)
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return r
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def _build_params(self, settings):
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params = dict(settings or {})
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if self.username:
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params['username'] = username
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if self.password:
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params['password'] = password
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return params
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