apdbSqlSchema.py

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# This file is part of dax_apdb.
#
# Developed for the LSST Data Management System.
# This product includes software developed by the LSST Project
# (http://www.lsst.org).
# See the COPYRIGHT file at the top-level directory of this distribution
# for details of code ownership.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
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# GNU General Public License for more details.
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"""Module responsible for APDB schema operations.
"""
 
from __future__ import annotations
 
__all__ = ["ApdbSqlSchema"]
 
import logging
from typing import Any, Dict, List, Mapping, Type
 
import sqlalchemy
from sqlalchemy import (Column, Index, MetaData, PrimaryKeyConstraint,
                        UniqueConstraint, Table)
 
from .apdbSchema import ApdbSchema, ApdbTables, ColumnDef, IndexDef, IndexType
 
 
_LOG = logging.getLogger(__name__)
 
 
class ApdbSqlSchema(ApdbSchema):
    """Class for management of APDB schema.
 
    Attributes
    ----------
    objects : `sqlalchemy.Table`
        DiaObject table instance
    objects_last : `sqlalchemy.Table`
        DiaObjectLast table instance, may be None
    sources : `sqlalchemy.Table`
        DiaSource table instance
    forcedSources : `sqlalchemy.Table`
        DiaForcedSource table instance
 
    Parameters
    ----------
    engine : `sqlalchemy.engine.Engine`
        SQLAlchemy engine instance
    dia_object_index : `str`
        Indexing mode for DiaObject table, see `ApdbSqlConfig.dia_object_index`
        for details.
    htm_index_column : `str`
        Name of a HTM index column for DiaObject and DiaSource tables.
    schema_file : `str`
        Name of the YAML schema file.
    schema_name : `str`, optional
        Name of the schema in YAML files.
    prefix : `str`, optional
        Prefix to add to all scheam elements.
    """
    def __init__(self, engine: sqlalchemy.engine.Engine, dia_object_index: str, htm_index_column: str,
                 schema_file: str, schema_name: str = "ApdbSchema", prefix: str = ""):
 
        super().__init__(schema_file, schema_name)
 
        self._engine_engine = engine
        self._dia_object_index_dia_object_index = dia_object_index
        self._prefix_prefix = prefix
 
        self._metadata_metadata = MetaData(self._engine_engine)
 
        # map YAML column types to SQLAlchemy
        self._type_map_type_map = dict(double=self._getDoubleType_getDoubleType(engine),
                              float=sqlalchemy.types.Float,
                              timestamp=sqlalchemy.types.TIMESTAMP,
                              long=sqlalchemy.types.BigInteger,
                              int=sqlalchemy.types.Integer,
                              short=sqlalchemy.types.Integer,
                              byte=sqlalchemy.types.Integer,
                              binary=sqlalchemy.types.LargeBinary,
                              text=sqlalchemy.types.CHAR,
                              string=sqlalchemy.types.CHAR,
                              char=sqlalchemy.types.CHAR,
                              unicode=sqlalchemy.types.CHAR,
                              boolean=sqlalchemy.types.Boolean)
 
        # Adjust index if needed
        if self._dia_object_index_dia_object_index == 'pix_id_iov':
            objects = self.tableSchemastableSchemas[ApdbTables.DiaObject]
            objects.primary_key.columns.insert(0, htm_index_column)
 
        # Add pixelId column and index to tables that need it
        for table in (ApdbTables.DiaObject, ApdbTables.DiaObjectLast, ApdbTables.DiaSource):
            tableDef = self.tableSchemastableSchemas.get(table)
            if not tableDef:
                continue
            column = ColumnDef(name=htm_index_column,
                               type="long",
                               nullable=False,
                               default=None,
                               description="",
                               unit="",
                               ucd="")
            tableDef.columns.append(column)
 
            if table is ApdbTables.DiaObjectLast:
                # use it as a leading PK column
                tableDef.primary_key.columns.insert(0, htm_index_column)
            else:
                # make a regular index
                index = IndexDef(name=f"IDX_{tableDef.name}_{htm_index_column}",
                                 type=IndexType.INDEX, columns=[htm_index_column])
                tableDef.indices.append(index)
 
        # generate schema for all tables, must be called last
        self._tables_tables = self._makeTables_makeTables()
 
        self.objectsobjects = self._tables_tables[ApdbTables.DiaObject]
        self.objects_lastobjects_last = self._tables_tables.get(ApdbTables.DiaObjectLast)
        self.sourcessources = self._tables_tables[ApdbTables.DiaSource]
        self.forcedSourcesforcedSources = self._tables_tables[ApdbTables.DiaForcedSource]
        self.ssObjectsssObjects = self._tables_tables[ApdbTables.SSObject]
 
    def _makeTables(self, mysql_engine: str = 'InnoDB') -> Mapping[ApdbTables, Table]:
        """Generate schema for all tables.
 
        Parameters
        ----------
        mysql_engine : `str`, optional
            MySQL engine type to use for new tables.
        """
 
        info: Dict[str, Any] = {}
 
        tables = {}
        for table_enum in ApdbTables:
 
            if table_enum is ApdbTables.DiaObjectLast and self._dia_object_index_dia_object_index != "last_object_table":
                continue
 
            columns = self._tableColumns_tableColumns(table_enum)
            constraints = self._tableIndices_tableIndices(table_enum, info)
            table = Table(table_enum.table_name(self._prefix_prefix),
                          self._metadata_metadata,
                          *columns,
                          *constraints,
                          mysql_engine=mysql_engine,
                          info=info)
            tables[table_enum] = table
 
        return tables
 
    def makeSchema(self, drop: bool = False, mysql_engine: str = 'InnoDB') -> None:
        """Create or re-create all tables.
 
        Parameters
        ----------
        drop : `bool`, optional
            If True then drop tables before creating new ones.
        mysql_engine : `str`, optional
            MySQL engine type to use for new tables.
        """
 
        # re-make table schema for all needed tables with possibly different options
        _LOG.debug("clear metadata")
        self._metadata_metadata.clear()
        _LOG.debug("re-do schema mysql_engine=%r", mysql_engine)
        self._makeTables_makeTables(mysql_engine=mysql_engine)
 
        # create all tables (optionally drop first)
        if drop:
            _LOG.info('dropping all tables')
            self._metadata_metadata.drop_all()
        _LOG.info('creating all tables')
        self._metadata_metadata.create_all()
 
    def _tableColumns(self, table_name: ApdbTables) -> List[Column]:
        """Return set of columns in a table
 
        Parameters
        ----------
        table_name : `ApdbTables`
            Name of the table.
 
        Returns
        -------
        column_defs : `list`
            List of `Column` objects.
        """
 
        # get the list of columns in primary key, they are treated somewhat
        # specially below
        table_schema = self.tableSchemastableSchemas[table_name]
        pkey_columns = set()
        for index in table_schema.indices:
            if index.type is IndexType.PRIMARY:
                pkey_columns = set(index.columns)
                break
 
        # convert all column dicts into alchemy Columns
        column_defs = []
        for column in table_schema.columns:
            kwargs: Dict[str, Any] = dict(nullable=column.nullable)
            if column.default is not None:
                kwargs.update(server_default=str(column.default))
            if column.name in pkey_columns:
                kwargs.update(autoincrement=False)
            ctype = self._type_map_type_map[column.type]
            column_defs.append(Column(column.name, ctype, **kwargs))
 
        return column_defs
 
    def _tableIndices(self, table_name: ApdbTables, info: Dict) -> List[sqlalchemy.schema.Constraint]:
        """Return set of constraints/indices in a table
 
        Parameters
        ----------
        table_name : `ApdbTables`
            Name of the table.
        info : `dict`
            Additional options passed to SQLAlchemy index constructor.
 
        Returns
        -------
        index_defs : `list`
            List of SQLAlchemy index/constraint objects.
        """
 
        table_schema = self.tableSchemastableSchemas[table_name]
 
        # convert all index dicts into alchemy Columns
        index_defs: List[sqlalchemy.schema.Constraint] = []
        for index in table_schema.indices:
            if index.type is IndexType.INDEX:
                index_defs.append(Index(self._prefix_prefix + index.name, *index.columns, info=info))
            else:
                kwargs = {}
                if index.name:
                    kwargs['name'] = self._prefix_prefix + index.name
                if index.type is IndexType.PRIMARY:
                    index_defs.append(PrimaryKeyConstraint(*index.columns, **kwargs))
                elif index.type is IndexType.UNIQUE:
                    index_defs.append(UniqueConstraint(*index.columns, **kwargs))
 
        return index_defs
 
    @classmethod
    def _getDoubleType(cls, engine: sqlalchemy.engine.Engine) -> Type:
        """DOUBLE type is database-specific, select one based on dialect.
 
        Parameters
        ----------
        engine : `sqlalchemy.engine.Engine`
            Database engine.
 
        Returns
        -------
        type_object : `object`
            Database-specific type definition.
        """
        if engine.name == 'mysql':
            from sqlalchemy.dialects.mysql import DOUBLE
            return DOUBLE(asdecimal=False)
        elif engine.name == 'postgresql':
            from sqlalchemy.dialects.postgresql import DOUBLE_PRECISION
            return DOUBLE_PRECISION
        elif engine.name == 'oracle':
            from sqlalchemy.dialects.oracle import DOUBLE_PRECISION
            return DOUBLE_PRECISION
        elif engine.name == 'sqlite':
            # all floats in sqlite are 8-byte
            from sqlalchemy.dialects.sqlite import REAL
            return REAL
        else:
            raise TypeError('cannot determine DOUBLE type, unexpected dialect: ' + engine.name)