def get(self, database, table):
if not os.path.exists(self.db_file):
return None
table = to_bytes(table)
database = to_bytes(database)
meta = None
with open(self.db_file, "rb") as f:
content = f.read(ctypes.sizeof(MetaStruct))
while content:
meta = MetaStruct.from_buffer_copy(content)
if meta.database == database and meta.table == table:
break
content = f.read(ctypes.sizeof(MetaStruct))
meta = None
return meta
def create(self, database, table, primary_key, columns):
table = to_bytes(table)
columns = to_bytes(columns)
database = to_bytes(database)
primary_key = to_bytes(primary_key)
meta = MetaStruct()
meta.database = database
meta.table = table
meta.primary_key = primary_key
meta.columns = columns
meta.auto_pk_value = 0
with open(self.db_file, "ab+") as f:
meta.offset = f.tell()
f.write(bytes(meta))
def find_by_index(self, value):
value = to_bytes(value)
index = self.index.get(value=value)
if not index:
print("index not found.")
return
with open(self.db_file, "rb") as f:
f.seek(index.data_offset)
content = f.read(ctypes.sizeof(BucketStruct))
bucket = BucketStruct.from_buffer_copy(content)
return bucket
def find(self, name):
name = to_bytes(name)
bucket = None
with open(self.db_file, "rb") as f:
content = f.read(ctypes.sizeof(BucketStruct))
while content:
bucket = BucketStruct.from_buffer_copy(content)
if bucket.name == name:
break
content = f.read(ctypes.sizeof(BucketStruct))
bucket = None
return bucket
def add(self, name, public):
pk_value = self.meta.get_next_pk(database=self.database,
table=self.table)
bucket = BucketStruct()
bucket.id = pk_value
bucket.name = to_bytes(name)
bucket.public = public
with open(self.db_file, "ab") as f:
data_offset = f.tell()
f.write(bytes(bucket))
self.index.create(value=pk_value, data_offset=data_offset)
return bucket
def create(self, value, data_offset):
# key = to_bytes(key)
value = to_bytes(value)
# table = to_bytes(table)
# database = to_bytes(database)
index = IndexStruct()
# index.database = self.database
# index.table = self.table
# index.key = self.key
index.value = value
index.offset = 0
index.data_offset = data_offset
self.btree.add(index)
self.btree.saveTree()