minos.aggregate.snapshots.pg.readers module

class minos.aggregate.snapshots.pg.readers.PostgreSqlSnapshotReader(host, port, database, user, password, *args, **kwargs)[source]

Bases: minos.aggregate.snapshots.pg.abc.PostgreSqlSnapshotSetup

PostgreSQL Snapshot class.

The snapshot provides a direct accessor to the aggregate instances stored as events by the event repository class.

__init__(host, port, database, user, password, *args, **kwargs)
property already_destroyed: bool

Already Destroy getter.

Return type

bool

Returns

A boolean value.

property already_setup: bool

Already Setup getter.

Return type

bool

Returns

A boolean value.

cursor(*args, **kwargs)

Get a new cursor.

Parameters

  • args – Additional positional arguments.

  • kwargs – Additional named arguments.

Return type

typing.AsyncContextManager[aiopg.connection.Cursor]

Returns

A Cursor wrapped into an asynchronous context manager.

async destroy()

Destroy miscellaneous repository things.

Return type

None

Returns

This method does not return anything.

async find(*args, **kwargs)[source]

Find a collection of Aggregate instances based on a Condition.

Parameters

  • args – Additional positional arguments.

  • kwargs – Additional named arguments.

Return type

typing.AsyncIterator[minos.aggregate.models.aggregates.Aggregate]

Returns

An asynchronous iterator that containing the Aggregate instances.

async find_entries(aggregate_name, condition, ordering=None, limit=None, streaming_mode=False, transaction=None, exclude_deleted=True, **kwargs)[source]

Find a collection of SnapshotEntry instances based on a Condition.

Parameters

  • aggregate_name (str) – Class name of the Aggregate.

  • condition (minos.aggregate.queries._Condition) – The condition that must be satisfied by the Aggregate instances.

  • ordering (typing.Optional[minos.aggregate.queries._Ordering]) – Optional argument to return the instance with specific ordering strategy. The default behaviour is to retrieve them without any order pattern.

  • limit (typing.Optional[int]) – Optional argument to return only a subset of instances. The default behaviour is to return all the instances that meet the given condition.

  • streaming_mode (bool) – If True return the values in streaming directly from the database (keep an open database connection), otherwise preloads the full set of values on memory and then retrieves them.

  • transaction (typing.Optional[minos.aggregate.transactions.entries.TransactionEntry]) – The transaction within the operation is performed. If not any value is provided, then the transaction is extracted from the context var. If not any transaction is being scoped then the query is performed to the global snapshot.

  • exclude_deleted (bool) – If True, deleted Aggregate entries are included, otherwise deleted Aggregate entries are filtered.

  • kwargs – Additional named arguments.

Return type

typing.AsyncIterator[minos.aggregate.snapshots.entries.SnapshotEntry]

Returns

An asynchronous iterator that containing the Aggregate instances.

classmethod from_config(config=None, **kwargs)

Build a new instance from config.

Parameters

  • config (typing.Union[minos.common.configuration.config.MinosConfig, pathlib.Path, None]) – Config instance. If None is provided, default config is chosen.

  • kwargs – Additional named arguments.

Return type

~S

Returns

A instance of the called class.

async get(aggregate_name, uuid, **kwargs)[source]

Get an aggregate instance from its identifier.

Parameters

  • aggregate_name (str) – Class name of the Aggregate.

  • uuid (uuid.UUID) – Identifier of the Aggregate.

  • kwargs – Additional named arguments.

Return type

minos.aggregate.models.aggregates.Aggregate

Returns

The Aggregate instance.

async get_entry(aggregate_name, uuid, **kwargs)[source]

Get a SnapshotEntry from its identifier.

Parameters

  • aggregate_name (str) – Class name of the Aggregate.

  • uuid (uuid.UUID) – Identifier of the Aggregate.

  • kwargs – Additional named arguments.

Return type

minos.aggregate.snapshots.entries.SnapshotEntry

Returns

The SnapshotEntry instance.

locked_cursor(key, *args, **kwargs)

Get a new locked cursor.

Parameters

  • key (collections.abc.Hashable) – The key to be used for locking.

  • args – Additional positional arguments.

  • kwargs – Additional named arguments.

Return type

typing.AsyncContextManager[aiopg.connection.Cursor]

Returns

A Cursor wrapped into an asynchronous context manager.

property pool: minos.common.database.pools.PostgreSqlPool

Get the connections pool.

Return type

minos.common.database.pools.PostgreSqlPool

Returns

A Pool object.

async setup()

Setup miscellaneous repository things.

Return type

None

Returns

This method does not return anything.

async submit_query(operation, parameters=None, *, timeout=None, lock=None, **kwargs)

Submit a SQL query.

Parameters

  • operation (typing.Any) – Query to be executed.

  • parameters (typing.Optional[typing.Any]) – Parameters to be projected into the query.

  • timeout (typing.Optional[float]) – An optional timeout.

  • lock (typing.Optional[typing.Any]) – Optional key to perform the query with locking. If not set, the query is performed without any lock.

  • kwargs – Additional named arguments.

Return type

None

Returns

This method does not return anything.

async submit_query_and_fetchone(*args, **kwargs)

Submit a SQL query and gets the first response.

Parameters

  • args – Additional positional arguments.

  • kwargs – Additional named arguments.

Return type

tuple

Returns

This method does not return anything.

async submit_query_and_iter(operation, parameters=None, *, timeout=None, lock=None, streaming_mode=False, **kwargs)

Submit a SQL query and return an asynchronous iterator.

Parameters

  • operation (typing.Any) – Query to be executed.

  • parameters (typing.Optional[typing.Any]) – Parameters to be projected into the query.

  • timeout (typing.Optional[float]) – An optional timeout.

  • lock (typing.Optional[int]) – Optional key to perform the query with locking. If not set, the query is performed without any lock.

  • streaming_mode (bool) – If True the data fetching is performed in streaming mode, that is iterating over the cursor and yielding once a time (requires an opening connection to do that). Otherwise, all the data is fetched and keep in memory before yielding it.

  • kwargs – Additional named arguments.

Return type

typing.AsyncIterator[tuple]

Returns

This method does not return anything.