class StorageEngine:
"""
A storage engine implementation, containing a file manager and buffer pool.
This provides a high-level API to operate on database relations and tuples
based on the functionality provided by the buffer pool, file manager and
the remaining components of the storage engine.
>>> schema = DBSchema('employee', [('id', 'int'), ('age', 'int')])
>>> storage = StorageEngine()
>>> list(storage.relations())
[]
# Create employee relation
>>> storage.createRelation(schema.name, schema)
# Populate relation
>>> for tup in [schema.pack(schema.instantiate(i, 2*i+20)) for i in range(20)]:
... _ = storage.insertTuple(schema.name, tup)
...
# Test table scan
>>> [schema.unpack(tup).id for tup in storage.tuples(schema.name)] == list(range(20))
True
"""
def __init__(self, **kwargs):
other = kwargs.get("other", None)
if other:
self.fromOther(other)
else:
bpArgs = {k: v for (k, v) in kwargs.items() if k in ["pageSize", "poolSize"]}
fmArgs = {k: v for (k, v) in kwargs.items() if k in ["pageSize", "dataDir", "indexDir"]}
self.bufferPool = BufferPool(**bpArgs)
self.fileMgr = FileManager(bufferPool=self.bufferPool, **fmArgs)
if self.fileMgr:
self.bufferPool.setFileManager(self.fileMgr)
def fromOther(self, other):
self.bufferPool = other.bufferPool
self.fileMgr = other.fileMgr
def close(self):
if self.fileMgr:
self.fileMgr.close()
# Data definition operations
def relations(self):
if self.fileMgr:
return self.fileMgr.relations()
def hasRelation(self, relId):
if self.fileMgr:
return self.fileMgr.hasRelation(relId)
def createRelation(self, relId, schema):
if self.fileMgr:
self.fileMgr.createRelation(relId, schema)
else:
raise ValueError("Could not create relation, no file manager found")
def removeRelation(self, relId):
if self.fileMgr:
self.fileMgr.removeRelation(relId)
else:
raise ValueError("Could not remove relation, no file manager found")
def relationStats(self, relId):
if self.fileMgr:
(_, rf) = self.fileMgr.relationFile(relId)
if rf:
return (rf.pageSize(), rf.numPages(), rf.numTuples())
else:
raise ValueError("Could not find relation " + relId + " in file manager")
else:
raise ValueError("Could not find relation stats, no file manager found")
def hasIndex(self, relId, keySchema):
if self.fileMgr:
return self.fileMgr.hasIndex(relId, keySchema)
def createIndex(self, relId, relSchema, keySchema, primary):
if self.fileMgr:
return self.fileMgr.createIndex(relId, relSchema, keySchema, primary)
def addIndex(self, relId, relSchema, keySchema, primary, indexId, indexDb):
if self.fileMgr:
self.fileMgr.addIndex(relId, relSchema, keySchema, primary, indexId, indexDb)
def removeIndex(self, relId, indexId):
if self.fileMgr:
self.fileMgr.removeIndex(relId, indexId)
def getIndex(self, indexId):
if self.fileMgr:
return self.fileMgr.getIndex(indexId)
# Data manipulation operations
# Returns a tuple id for the newly inserted data.
def insertTuple(self, relId, tupleData):
if self.fileMgr:
return self.fileMgr.insertTuple(relId, tupleData)
else:
raise ValueError("Could not insert tuple, no file manager found")
def deleteTuple(self, relId, tupleId):
if self.fileMgr:
self.fileMgr.deleteTuple(relId, tupleId)
else:
raise ValueError("Could not delete tuple, no file manager found")
def updateTuple(self, relId, tupleId, tupleData):
if self.fileMgr:
self.fileMgr.updateTuple(relId, tupleId, tupleData)
else:
raise ValueError("Could not update tuple, no file manager found")
# Tuple-based table scan
def tuples(self, relId):
if self.fileMgr:
return self.fileMgr.tuples(relId)
# Page-based table scan
def pages(self, relId):
if self.fileMgr:
return self.fileMgr.pages(relId)
class StorageEngine:
"""
A storage engine implementation, containing a file manager and buffer pool.
This provides a high-level API to operate on database relations and tuples
based on the functionality provided by the buffer pool, file manager and
the remaining components of the storage engine.
>>> schema = DBSchema('employee', [('id', 'int'), ('age', 'int')])
>>> storage = StorageEngine()
>>> list(storage.relations())
[]
# Create employee relation
>>> storage.createRelation(schema.name, schema)
# Populate relation
>>> for tup in [schema.pack(schema.instantiate(i, 2*i+20)) for i in range(20)]:
... _ = storage.insertTuple(schema.name, tup)
...
# Test table scan
>>> [schema.unpack(tup).id for tup in storage.tuples(schema.name)] == list(range(20))
True
"""
def __init__(self, **kwargs):
other = kwargs.get("other", None)
if other:
self.fromOther(other)
else:
bpArgs = {
k: v
for (k, v) in kwargs.items() if k in ["pageSize", "poolSize"]
}
fmArgs = {
k: v
for (k, v) in kwargs.items()
if k in ["pageSize", "dataDir", "indexDir"]
}
self.bufferPool = BufferPool(**bpArgs)
self.fileMgr = FileManager(bufferPool=self.bufferPool, **fmArgs)
if self.fileMgr:
self.bufferPool.setFileManager(self.fileMgr)
def fromOther(self, other):
self.bufferPool = other.bufferPool
self.fileMgr = other.fileMgr
def close(self):
if self.fileMgr:
self.fileMgr.close()
# Data definition operations
def relations(self):
if self.fileMgr:
return self.fileMgr.relations()
def hasRelation(self, relId):
if self.fileMgr:
return self.fileMgr.hasRelation(relId)
def createRelation(self, relId, schema):
if self.fileMgr:
self.fileMgr.createRelation(relId, schema)
else:
raise ValueError(
"Could not create relation, no file manager found")
def removeRelation(self, relId):
if self.fileMgr:
self.fileMgr.removeRelation(relId)
else:
raise ValueError(
"Could not remove relation, no file manager found")
def relationStats(self, relId):
if self.fileMgr:
(_, rf) = self.fileMgr.relationFile(relId)
if rf:
return (rf.pageSize(), rf.numPages(), rf.numTuples())
else:
raise ValueError("Could not find relation " + relId +
" in file manager")
else:
raise ValueError(
"Could not find relation stats, no file manager found")
def hasIndex(self, relId, keySchema):
if self.fileMgr:
return self.fileMgr.hasIndex(relId, keySchema)
def createIndex(self, relId, relSchema, keySchema, primary):
if self.fileMgr:
return self.fileMgr.createIndex(relId, relSchema, keySchema,
primary)
def addIndex(self, relId, relSchema, keySchema, primary, indexId, indexDb):
if self.fileMgr:
self.fileMgr.addIndex(relId, relSchema, keySchema, primary,
indexId, indexDb)
def removeIndex(self, relId, indexId):
if self.fileMgr:
self.fileMgr.removeIndex(relId, indexId)
def getIndex(self, indexId):
if self.fileMgr:
return self.fileMgr.getIndex(indexId)
# Data manipulation operations
# Returns a tuple id for the newly inserted data.
def insertTuple(self, relId, tupleData):
if self.fileMgr:
return self.fileMgr.insertTuple(relId, tupleData)
else:
raise ValueError("Could not insert tuple, no file manager found")
def deleteTuple(self, relId, tupleId):
if self.fileMgr:
self.fileMgr.deleteTuple(relId, tupleId)
else:
raise ValueError("Could not delete tuple, no file manager found")
def updateTuple(self, relId, tupleId, tupleData):
if self.fileMgr:
self.fileMgr.updateTuple(relId, tupleId, tupleData)
else:
raise ValueError("Could not update tuple, no file manager found")
# Tuple-based table scan
def tuples(self, relId):
if self.fileMgr:
return self.fileMgr.tuples(relId)
# Page-based table scan
def pages(self, relId):
if self.fileMgr:
return self.fileMgr.pages(relId)
class StorageEngine:
"""
A storage engine implementation, containing a file manager and buffer pool.
This provides a high-level API to operate on database relations and tuples
based on the functionality provided by the buffer pool, file manager and
the remaining components of the storage engine.
>>> schema = DBSchema('employee', [('id', 'int'), ('age', 'int')])
>>> storage = StorageEngine()
>>> list(storage.relations())
[]
# Create employee relation
>>> storage.createRelation(schema.name, schema)
# Populate relation
>>> for tup in [schema.pack(schema.instantiate(i, 2*i+20)) for i in range(20)]:
... _ = storage.insertTuple(schema.name, tup)
...
# Test table scan
>>> [schema.unpack(tup).id for tup in storage.tuples(schema.name)] == list(range(20))
True
"""
def __init__(self, **kwargs):
other = kwargs.get("other", None)
if other:
self.fromOther(other)
else:
pageSize = kwargs.get("pageSize", io.DEFAULT_BUFFER_SIZE)
self.bufferPool = BufferPool(pageSize=pageSize)
self.fileMgr = FileManager(pageSize=pageSize, bufferPool=self.bufferPool)
if self.fileMgr:
self.bufferPool.setFileManager(self.fileMgr)
def fromOther(self, other):
self.bufferPool = other.bufferPool
self.fileMgr = other.fileMgr
# Data definition operations
def relations(self):
if self.fileMgr:
return self.fileMgr.relations()
def hasRelation(self, relId):
if self.fileMgr:
return self.fileMgr.hasRelation(relId)
def createRelation(self, relId, schema):
if self.fileMgr:
self.fileMgr.createRelation(relId, schema)
else:
raise ValueError("Could not create relation, no file manager found")
def removeRelation(self, relId):
if self.fileMgr:
self.fileMgr.removeRelation(relId)
else:
raise ValueError("Could not remove relation, no file manager found")
# Data manipulation operations
# Returns a tuple id for the newly inserted data.
def insertTuple(self, relId, tupleData):
if self.fileMgr:
return self.fileMgr.insertTuple(relId, tupleData)
else:
raise ValueError("Could not insert tuple, no file manager found")
def deleteTuple(self, tupleId):
if self.fileMgr:
self.fileMgr.deleteTuple(tupleId)
else:
raise ValueError("Could not delete tuple, no file manager found")
def updateTuple(self, tupleId, tupleData):
if self.fileMgr:
self.fileMgr.updateTuple(tupleId, tupleData)
else:
raise ValueError("Could not update tuple, no file manager found")
# Tuple-based table scan
def tuples(self, relId):
if self.fileMgr:
return self.fileMgr.tuples(relId)
# Page-based table scan
def pages(self, relId):
if self.fileMgr:
return self.fileMgr.pages(relId)