def insert(self, value, record):
start = timer()
if self.workings:
print("Search for key value first to ensure record does not already exist.")
if not (self.utilSearch(value, False, False) is None):
print("Record with that key already exists, cannot insert.")
return
if self.workings:
print("Begin insert.")
#using the hash function
bucket = self.getBucketPointer(value)
if self.workings:
print(str(value) + " maps to bucket " + str(bucket))
#format the record to be inserted
formattedRecord = Record.new(self.recordSize, self.fieldSize, False, value, record)
#open the file as binary read and write
with open(self.file, 'r+b', buffering=self.blockSize) as f:
#navigate to the appropriate bucket
f.seek(self.blockSize*(bucket))
if self.workings:
print("Navigate to bucket " + str(bucket))
#check to see if data exits in this bucket
theBlock = self.makeBlock(f.read(self.blockSize))
space = theBlock.hasSpace()
if space>=0:
if self.workings:
print("Space " + str(space) + " is available in this bucket.")
# spot was open, move pointer back
f.seek(self.blockSize*(bucket) + self.recordSize*space)
#slot data in there boiiiiii
f.write(formattedRecord.bytes)
if self.workings:
print("The record was inserted at record number " + str(space) + " in bucket " + str(bucket) + ".")
else:
if self.workings:
print("The bucket is full. Initiate a split.")
# clear out bucket on disk
f.seek(self.blockSize*(bucket))
f.write(bytearray(self.blockSize))
self.split(f, theBlock, formattedRecord, value)
end = timer()
if self.times:
print("Insert time: " + str((end-start)*1000) + "ms")
def update(self, value, data):
start = timer()
#format record
formattedRecord = Record.new(self.recordSize, self.fieldSize, False, value, data)
bucket = self.getBucketPointer(value)
recordInfo = self.utilSearch(value, True, False)
if recordInfo is None:
print("Record not found.")
else:
# open the file as binary read and write
with open(self.file, 'r+b', buffering=self.blockSize) as f:
# navigate to the appropriate bucket
# plus 2 is to account for the header
f.seek(self.blockSize*(bucket))
# load bucket into memory
theBlock = self.makeBlock(f.read(self.blockSize))
if theBlock.containsRecordWithValue(value):
recLoc = theBlock.getRecordWithValueLoc(value)
f.seek(self.blockSize*bucket + self.recordSize*recLoc)
f.write(formattedRecord.bytes)
end = timer()
if self.times:
print("Search time: " + str((end-start)*1000) + "ms")
