taucmdr.cf.storage.sqlite3_file module¶

Local file backend for SQLite databases.

A persistent, transactional record storage system using sqlite3 for both the database and the key/value store.

class taucmdr.cf.storage.sqlite3_file.SQLiteDatabase(dbfile, storage=None)[source]¶

Bases: object

Represents a connection to the database.

dbfile¶

Path to database file

Type:	str

close()[source]¶

Close the database connection

commit_transaction()[source]¶

Commit a transaction previously started with _SQLiteDatabase.start_transaction

cursor()[source]¶

Returns a cursor which can be used to query the SQLite database

open()[source]¶

Open the database connection specified in this object’s dbfile attribute

purge()[source]¶

Delete every record in every table in the database. :raises: SQLiteStorageError – Attempt to perform and operation on a database which is not open

revert_transaction()[source]¶

Revert a transaction previously started with _SQLiteDatabase.start_transaction

start_transaction()[source]¶

Begin a transaction, which can be reverted with _SQLiteDatabase.revert_transaction or committed with _SQLiteDatabase.commit_transaction.

table(table_name)[source]¶

Get a table object for a table in this database. :param table_name: The name of the table requested :type table_name: str

Returns:	A table object for the table table_name
Raises:	SQLiteStorageError – Attempt to perform and operation on a database which is not open

tables()[source]¶

Get a list of all the tables in the database :returns: A list of the target names for the tables in the database.

Raises:	SQLiteStorageError – Attempt to perform and operation on a database which is not open

class taucmdr.cf.storage.sqlite3_file.SQLiteLocalFileStorage(name, prefix)[source]¶

Bases: taucmdr.cf.storage.local_file.LocalFileStorage

A persistent, transactional record storage system.

Uses sqlite3 for both the database and the key/value store.

dbfile¶

Absolute path to database file.

Type:	str

Record¶

alias of _SQLiteJsonRecord

__enter__()[source]¶

Initiates the database transaction.

__exit__(ex_type, value, traceback)[source]¶

Finalizes the database transaction.

__str__()[source]¶

Human-readable identifier for this database.

connect_database(*args, **kwargs)[source]¶

Open the database for reading and writing.

contains(keys, table_name=None, match_any=False)[source]¶

Check if the specified table contains at least one matching record.

The behavior depends on the type of keys:

• self.Record.eid_type: check for the record with that element identifier.
• dict: check for the record with attributes matching keys.
• list or tuple: return the equivalent of map(contains, keys).
• None: return False.

Parameters:	keys – Fields or element identifiers to match. table_name (str) – Name of the table to operate on. See AbstractDatabase.table. match_any (bool) – Only applies if keys is a dictionary. If True then any key in keys may match or if False then all keys in keys must match.
Returns:	True if the table contains at least one matching record, False otherwise.
Return type:	bool
Raises:	ValueError – Invalid value for keys.

count(table_name=None)[source]¶

Count the records in the database.

Parameters:	table_name (str) – Name of the table to operate on. See AbstractDatabase.table.
Returns:	Number of records in the table.
Return type:	int

database_exists()[source]¶

Determine if the database file backing this Storage object exists.

Returns:	True if database exists; false otherwise.
Return type:	bool

dbfile

disconnect_database(*args, **kwargs)[source]¶

Close the database for reading and writing.

get(keys, table_name=None, match_any=False)[source]¶

Find a single record.

The behavior depends on the type of keys:

• self.Record.eid_type: return the record with that element identifier.
• dict: return the record with attributes matching keys.
• list or tuple: return a list of records matching the elements of keys
• None: return None.

Parameters:	keys – Fields or element identifiers to match. table_name (str) – Name of the table to operate on. See AbstractDatabase.table. match_any (bool) – Only applies if keys is a dictionary. If True then any key in keys may match or if False then all keys in keys must match.
Returns:	The matching data record if keys was a self.Record.eid_type or dict. list: All matching data records if keys was a list or tuple. None: No record found or bool(keys) == False.
Return type:	Record
Raises:	ValueError – Invalid value for keys.

insert(data, table_name=None)[source]¶

Create a new record.

If the table doesn’t exist it will be created.

Parameters:	data (dict) – Data to insert in table. table_name (str) – Name of the table to operate on. See AbstractDatabase.table.
Returns:	The new record.
Return type:	Record

match(field, table_name=None, regex=None, test=None)[source]¶

Find records where field matches regex or test.

Either regex or test may be specified, not both. If regex is given, then all records with field matching the regular expression are returned. If test is given then all records with field set to a value that caues test to return True are returned. If neither is given, return all records where field is set to any value.

Parameters:	table_name (str) – Name of the table to operate on. See AbstractDatabase.table. field (string) – Name of the data field to match. regex (string) – Regular expression string. test – Callable returning a boolean value.
Returns:	Matching data records.
Return type:	list
Raises:	ValueError – Invalid value for keys.

purge(table_name=None)[source]¶

Delete all records.

Parameters:	table_name (str) – Name of the table to operate on. See AbstractDatabase.table.

remove(keys, table_name=None, match_any=False)[source]¶

Delete records.

The behavior depends on the type of keys:

• self.Record.eid_type: delete the record with that element identifier.
• dict: delete all records with attributes matching keys.
• list or tuple: delete all records matching the elements of keys.

Parameters:	keys – Fields or element identifiers to match. table_name (str) – Name of the table to operate on. See AbstractDatabase.table. match_any (bool) – Only applies if keys is a dictionary. If True then any key in keys may match or if False then all keys in keys must match.
Raises:	ValueError – bool(keys) == False or invalid value for keys.

search(keys=None, table_name=None, match_any=False)[source]¶

Find multiple records.

The behavior depends on the type of keys:

• self.Record.eid_type: return the record with that element identifier.
• dict: return all records with attributes matching keys.
• list or tuple: return a list of records matching the elements of keys
• None: return all records.

Parameters:	keys – Fields or element identifiers to match. table_name (str) – Name of the table to operate on. See AbstractDatabase.table. match_any (bool) – Only applies if keys is a dictionary. If True then any key in keys may match or if False then all keys in keys must match.
Returns:	Matching data records.
Return type:	list
Raises:	ValueError – Invalid value for keys.

table(table_name)[source]¶

Return a handle to a table.

Return a handle to the named table or, if table_name is None, return the default table.

Parameters:	table_name (str) – Name of the table or None.
Returns:	A database table object.
Return type:	object

unset(fields, keys, table_name=None, match_any=False)[source]¶

Update records by unsetting fields.

Update only allows you to update a record by adding new fields or overwriting existing fields. Use this method to remove a field from the record.

The behavior depends on the type of keys:

• self.Record.eid_type: update the record with that element identifier.
• dict: update all records with attributes matching keys.
• list or tuple: apply update to all records matching the elements of keys.

Parameters:	fields (list) – Names of fields to remove from matching records. keys – Fields or element identifiers to match. table_name (str) – Name of the table to operate on. See AbstractDatabase.table. match_any (bool) – Only applies if keys is a dictionary. If True then any key in keys may match or if False then all keys in keys must match.
Raises:	ValueError – bool(keys) == False or invalid value for keys.

update(fields, keys, table_name=None, match_any=False)[source]¶

Update records.

The behavior depends on the type of keys:

• self.Record.eid_type: update the record with that element identifier.
• dict: update all records with attributes matching keys.
• list or tuple: apply update to all records matching the elements of keys.

Parameters:	fields (dict) – Data to record. keys – Fields or element identifiers to match. table_name (str) – Name of the table to operate on. See AbstractDatabase.table. match_any (bool) – Only applies if keys is a dictionary. If True then any key in keys may match or if False then all keys in keys must match.
Raises:	ValueError – bool(keys) == False or invalid value for keys.

exception taucmdr.cf.storage.sqlite3_file.SQLiteStorageError(table_name=None)[source]¶

Bases: taucmdr.cf.storage.StorageError

Indicates that the database connection has not been initialized.

message_fmt = '%(value)s\n\n%(hints)s\nPlease contact %(contact)s for assistance.'¶

class taucmdr.cf.storage.sqlite3_file._SQLiteJsonTable(database, name)[source]¶

Bases: object

Represents a JSON Table within the SQLite database. Operations on the table are made through this class.

Attributes:

Record¶

alias of _SQLiteJsonRecord

count(cond, match_any=False)[source]¶

exists(field)[source]¶

get(keys=None, eid=None, match_any=False)[source]¶

insert(element)[source]¶

name¶

purge()[source]¶

remove(keys=None, eid=None, match_any=False)[source]¶

search(cond, match_any=False)[source]¶

update(fields, keys=None, eids=None, match_any=False, unset=False)[source]¶