querying Namespace Reference

Classes
class	connection
class	factory

Functions
def	_get_netrc_data (netrc_file, key)
def	connect (connection_data, mode="r", map_blobs=False, secrets=None, pooling=True)
def	engine_from_dictionary (dictionary, pooling=True)
def	new_connection_dictionary (connection_data, secrets=None, mode="r")

Detailed Description

connection class translates either a connection string for sqlite, oracle of frontier into a connection object.
Also sets up ORM with SQLAlchemy.

connection class can also take a pre-constructed engine - useful for web services.

Function Documentation

def querying._get_netrc_data (   netrc_file,   key  )

private

Returns a dictionary {login : ..., account : ..., password : ...}

Definition at line 334 of file querying.py.

References cmsPerfStripChart.dict, and ComparisonHelper.zip().

Referenced by new_connection_dictionary().

def _get_netrc_data(netrc_file, key):
    """
    Returns a dictionary {login : ..., account : ..., password : ...}
    """
    try:
        headers = ["login", "account", "password"]
        authenticator_tuple = netrc.netrc(netrc_file).authenticators(key)
        if authenticator_tuple == None:
            raise Exception("netrc file must contain key '%s'." % key)
    except:
        raise Exception("Couldn't get credentials from netrc file.")
    return dict(zip(headers, authenticator_tuple))

def querying.connect	(		connection_data,
			mode = "r",
			map_blobs = False,
			secrets = None,
			pooling = True
	)

Utility method for user - set up a connection object.

Definition at line 450 of file querying.py.

Referenced by shell.connect(), command_line.copy_global_tag(), command_line.copy_tag(), command_line.diff_of_gts(), command_line.diff_of_tags(), command_line.list_object(), command_line.search(), uploads.uploader.send_payloads(), and payload_tests.payload_tests.test_write_blob_to_sqlite().

def connect(connection_data, mode="r", map_blobs=False, secrets=None, pooling=True):
    """
    Utility method for user - set up a connection object.
    """
    con = connection(connection_data=connection_data, mode=mode, map_blobs=map_blobs, secrets=secrets, pooling=pooling)
    con = con.setup()
    return con

def querying.engine_from_dictionary	(		dictionary,
			pooling = True
	)

Definition at line 426 of file querying.py.

def engine_from_dictionary(dictionary, pooling=True):
    if dictionary["host"] != "sqlite":
        if dictionary["host"] != "frontier":
            # probably oracle
            # if not frontier, we have to authenticate
            user = dictionary["secrets"]["login"]
            pwd = dictionary["secrets"]["password"]
            # set max label length for oracle
            if pooling:
                return create_engine(connection.build_oracle_url(user, pwd, dictionary["database_name"]), label_length=6)
            else:
                return create_engine(connection.build_oracle_url(user, pwd, dictionary["database_name"]), label_length=6, poolclass=NullPool)
        else:
            # if frontier, no need to authenticate
            # set max label length for frontier
            if pooling:
                return create_engine(connection.build_frontier_url(dictionary["database_name"], dictionary["schema"]), label_length=6)
            else:
                return create_engine(connection.build_frontier_url(dictionary["database_name"], dictionary["schema"]), label_length=6, poolclass=NullPool)
    else:
        # if host is sqlite, making the url is easy - no authentication
        return create_engine("sqlite:///%s" % dictionary["database_name"])

def querying.new_connection_dictionary	(		connection_data,
			secrets = None,
			mode = "r"
	)

Function used to construct connection data dictionaries - internal to framework.

Definition at line 347 of file querying.py.

References _get_netrc_data(), split, and str.

def new_connection_dictionary(connection_data, secrets=None, mode="r"):
    """
    Function used to construct connection data dictionaries - internal to framework.
    """
    frontier_str_length = len("frontier://")
    sqlite_str_length = len("sqlite://")
    #sqlite_file_str_length = len("sqlite_file://")
    oracle_str_length = len("oracle://")

    if type(connection_data) in [str, unicode] and connection_data[0:frontier_str_length] == "frontier://":
        """
        frontier://database_name/schema
        """
        db_name = connection_data[frontier_str_length:].split("/")[0]
        schema = connection_data[frontier_str_length:].split("/")[1]
        connection_data = {}
        connection_data["database_name"] = db_name
        connection_data["schema"] = schema
        connection_data["host"] = "frontier"
        connection_data["secrets"] = None
    elif type(connection_data) in [str, unicode] and connection_data[0:sqlite_str_length] == "sqlite://":
        """
        sqlite://database_file_name
        """
        # for now, just support "sqlite://" format for sqlite connection strings
        db_name = connection_data[sqlite_str_length:]
        schema = ""
        connection_data = {}
        connection_data["database_name"] = os.path.abspath(db_name)
        connection_data["schema"] = schema
        connection_data["host"] = "sqlite"
        connection_data["secrets"] = None
    elif type(connection_data) in [str, unicode] and connection_data[0:oracle_str_length] == "oracle://":
        """
        oracle://account:password@database_name
        or
        oracle://database_name/schema (requires a separate method of authentication - either dictionary or netrc)
        """
        new_connection_string = connection_data[oracle_str_length:]

        if ":" in new_connection_string:
            # the user has given a password - usually in the case of the db upload service
            database_name = new_connection_string[new_connection_string.index("@")+1:]
            schema_name = new_connection_string[0:new_connection_string.index(":")]
            # set username based on connection string
            username = new_connection_string[0:new_connection_string.index(":")]
            password = new_connection_string[new_connection_string.index(":")+1:new_connection_string.index("@")]
        else:
            mode_to_netrc_key_suffix = {"r" : "read", "w" : "write"}
            database_name = new_connection_string[0:new_connection_string.index("/")]
            schema_name = new_connection_string[new_connection_string.index("/")+1:]
            if secrets == None:
                username = str(raw_input("Enter the username you want to connect to the schema '%s' with: " % (schema_name)))
                password = str(raw_input("Enter the password for the user '%s' in database '%s': " % (username, database_name)))
            else:
                if isinstance(secrets, str):
                    netrc_key = "%s/%s/%s" % (database_name, schema_name, mode_to_netrc_key_suffix[mode])
                    netrc_data = _get_netrc_data(secrets, key=netrc_key)
                    # take the username from the netrc entry corresponding to the mode the database is opened in
                    # eg, if the user has given mode="read", the database_name/schema_name/read entry will be taken
                    username = netrc_data["login"]
                    password = netrc_data["password"]
                elif isinstance(secrets, dict):
                    username = secrets["user"]
                    password = secrets["password"]
                else:
                    raise Exception("Invalid type given for secrets.  Either an str or a dict must be given.")

        #print("Connected to database %s, schema %s, with username %s." % (database_name, schema_name, username))

        connection_data = {}
        connection_data["database_name"] = database_name
        connection_data["schema"] = schema_name
        connection_data["password"] = password
        connection_data["host"] = "oracle"
        connection_data["secrets"] = {"login" : username, "password" : password}

    return connection_data

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