def get_digest_result(self):
"""Retrieving the digest of a particular ledger."""
try:
data = get_requested_data()
digest = get_digest_result(data["ledger_name"])
return digest
except Exception as e:
logger.exception('Unable to get a ledger digest!')
return fail_response('Unable to delete the ledger. Please try again.', HTTPStatus.UNPROCESSABLE_ENTITY)
def describe_ledger(ledger_name):
"""
Returns information about a ledger, including its state and when it was created.
"""
try:
logger.info("Let's describe ledger...{}".format(ledger_name))
ledger = qldb.client().describe_ledger(Name=ledger_name)
logger.info('Success. describe ledger...{}.'.format(ledger))
return ledger
except Exception as e:
logger.exception('Unable to list ledgers!')
return fail_response('Unable to list ledgers!. Please try again.',
HTTPStatus.UNPROCESSABLE_ENTITY)
def create_ledger(ledger_name):
"""Create a ledger and wait for it to be active."""
try:
DdlServices.do_create_ledger(ledger_name)
wait_for_active(ledger_name)
DdlServices.reset_ledgers()
return success_response('Ledger is active and ready to use.',
HTTPStatus.CREATED)
except Exception as e:
logger.exception('Unable to create the ledger!')
return fail_response(
'Unable to create the ledger. error: {}. Please try again.'.
format(e), HTTPStatus.UNPROCESSABLE_ENTITY)
def delete_ledger(ledger_name):
"""Delete a ledger."""
try:
set_deletion_protection(ledger_name, False)
DdlServices.do_delete_ledger(ledger_name)
wait_for_deleted(ledger_name)
DdlServices.reset_ledgers()
return success_response('The ledger is successfully deleted.',
HTTPStatus.ACCEPTED)
except Exception as e:
logger.exception('Unable to delete the ledger.')
return fail_response(
'Unable to delete the ledger. Please try again.',
HTTPStatus.UNPROCESSABLE_ENTITY)
def drop_table(ledger_name=None, table_name=None):
"""Create a Table"""
try:
with qldb.session(ledger_name) as session:
session.execute_lambda(
lambda x: DdlServices.do_drop_table(x, table_name),
lambda retry_attempt: logger.info(
'Retrying due to OCC conflict...'))
logger.info('Table dropped successfully.')
return success_response('Table dropped successfully.',
HTTPStatus.CREATED)
except Exception:
logger.exception('Error creating table.')
return fail_response(
'Unable to create the table. Please try again.',
HTTPStatus.UNPROCESSABLE_ENTITY)
def get_ledger_list():
"""
List all ledgers.
:rtype: list
:return: List of ledgers.
"""
try:
logger.info("Let's list all the ledgers...")
ledgers = DdlServices.ledger_list()
logger.info('Success. List of ledgers: {}.'.format(ledgers))
return ledgers
except Exception as e:
logger.exception('Unable to list ledgers!')
return fail_response('Unable to list ledgers!. Please try again.',
HTTPStatus.UNPROCESSABLE_ENTITY)
def insert_documents(ledger_name, table_name, documents):
"""
Insert documents into a table in a QLDB ledger.
"""
try:
with qldb.session(ledger_name) as session:
# An INSERT statement creates the initial revision of a document with a version number of zero.
# QLDB also assigns a unique document identifier in GUID format as part of the metadata.
session.execute_lambda(
lambda executor: DmlServices.do_insert_documents(executor, table_name, documents),
lambda retry_attempt: logger.info('Retrying due to OCC conflict...'))
logger.info('Documents inserted successfully!')
return success_response('Ledger is active and ready to use.', HTTPStatus.CREATED)
except Exception as e:
logger.exception('Error inserting or updating documents.')
return fail_response('Error inserting or updating documents. error: {}. Please try again.'.format(e),
HTTPStatus.UNPROCESSABLE_ENTITY)
def list_tables(ledger_name):
"""
Connect to a session for a given ledger using default settings.
"""
try:
qldb_session = qldb.session(ledger_name)
logger.info('Listing table names ')
tables = qldb_session.list_tables()
_tables = []
for table in tables:
_tables.append(table)
return _tables
except Exception as e:
logger.exception('Unable to create session.')
return fail_response(
'Unable to connect ledgers!. Please try again.',
HTTPStatus.UNPROCESSABLE_ENTITY)
def create_table_index(ledger_name=None,
table_name=None,
index_attribute=None):
"""Create index on tables in a particular ledger."""
logger.info('Creating index on all tables in a single transaction...')
try:
with qldb.session(ledger_name) as session:
session.execute_lambda(
lambda x: DdlServices.do_create_table_index(
x, table_name, index_attribute), lambda retry_attempt:
logger.info('Retrying due to OCC conflict...'))
logger.info('Index created successfully.')
return success_response('Index created successfully.',
HTTPStatus.CREATED)
except Exception:
logger.exception('Unable to create index.')
return fail_response(
'Unable to create the index. Please try again.',
HTTPStatus.UNPROCESSABLE_ENTITY)
