def get_key(self):
''' Get the current key at the iterator
:returns: The current key at the iterator
'''
size = new_native_size()
pointer = LDB.leveldb_iter_key(self.iterator, get_reference_to(size))
return as_python_string(pointer, size)
def get(self, key, verify_checksum=False, fill_cache=True):
''' Delete the supplied value at the given key.
:param key: The key to delete the value at
:throws DatabaseException: If an error has occurred
'''
result = None
options = self.get_read_options(verify_checksum, fill_cache)
try:
error = new_native_string()
size = new_native_size()
value = LDB.leveldb_get(self.database, options, key, len(key),
get_reference_to(size), get_reference_to(error))
self.handle_error(error)
return as_python_string(value, size)
finally:
if LDB and options:
LDB.leveldb_readoptions_destroy(options)
def assert_no_error(self):
''' Check if there was an error after the last error.
If there was, then throw an exception.
:throws DatabaseException: If there was a problem with the iterator
'''
error = new_native_string()
LDB.leveldb_iter_get_error(error, get_reference_to(error))
message = as_python_string(error)
if message:
raise DatabaseException(message)
def destroy(self):
''' Completely blows away the underlying database. This process
is not reversable.
:throws DatabaseException: If an error has occurred
'''
options = self.get_open_options()
try:
error = new_native_string()
LDB.leveldb_destroy_db(options, self.filename, get_reference_to(error))
self.handle_error(error)
finally:
if LDB and options:
LDB.leveldb_options_destroy(options)
self.close()
def repair(self):
''' Attempt to repair a database after setting paranoid checks
still results in an error.
:throws DatabaseException: If an error has occurred
'''
options = self.get_open_options()
try:
error = new_native_string()
LDB.leveldb_repair_db(options, self.filename, get_reference_to(error))
self.handle_error(error)
finally:
if LDB and options:
LDB.leveldb_options_destroy(options)
self.close()
def delete(self, key, synchronous=False):
''' Delete the supplied value at the given key.
:param key: The key to delete the value at
:param synchronous: True to make the put to disk synchronous, False to buffer
:throws DatabaseException: If an error has occurred
'''
options = LDB.leveldb_writeoptions_create()
try:
error = new_native_string()
LDB.leveldb_writeoptions_set_sync(options, synchronous)
LDB.leveldb_delete(self.database, options, key, len(key), get_reference_to(error))
self.handle_error(error)
finally:
if options: LDB.leveldb_writeoptions_destroy(options)
def write(self, write_batch, synchronous=False):
''' Apply the write batch to the datbase.
:param write_batch: The write batch to apply to the database.
:param synchronous: True to make the put to disk synchronous, False to buffer
:throws DatabaseException: If an error has occurred
'''
options = LDB.leveldb_writeoptions_create()
try:
error = new_native_string()
LDB.leveldb_writeoptions_set_sync(options, synchronous)
LDB.leveldb_write(self.database, options, write_batch, get_reference_to(error))
self.handle_error(error)
finally:
if options: LDB.leveldb_writeoptions_destroy(options)
def open(self):
''' Creates the neccessary data structures and opens the
underlying database. To tune the underlying options for the
database read the following:
http://docs.basho.com/riak/1.0.0/tutorials/choosing-a-backend/LevelDB/
:throws DatabaseException: If an error has occurred
'''
options = self.get_open_options()
try:
error = new_native_string()
self.database = LDB.leveldb_open(options, self.filename, get_reference_to(error))
self.handle_error(error)
finally:
LDB.leveldb_options_destroy(options)