"""

Retrieve records with a given data

"""

msg = "Please enter the data you would like to search for"

title = "Retrieve key with given data"

searchdata = eg.enterbox(msg, title)

if searchdata == None:

eg.msgbox("Operation cancelled.")

return

# Change the data from string to bytes:

bytes_data = searchdata.encode('utf-8')

time_before = time.time()

key = sec_cur.set(bytes_data)

time_after = time.time()

# Get time in microseconds

runtime = (time_after - time_before) * 1000000

# Results found

if (key):

# Append to answers file.

answers.write(key[1].decode('utf-8'))

answers.write('\n')

answers.write(key[0].decode('utf-8'))

answers.write('\n')

answers.write('\n')

text = ("Data input: \n{} \nKey value found: \n{} \nNumber of records retrieved: 1 \nTime: {} microseconds.".format(key[1].decode('utf-8'), key[0].decode('utf-8'), runtime))

# No results

else:

text = ("No results found for the following data: \n{} \nNumber of records retrieved: 0 \nTime: {} microseconds".format(searchdata, runtime))

msg = "Results:"

title = "Retrieve With Data"

"""

Creates and populates the database

"""

# gets the type from the arguements used to run the program

type = sys.argv

print("Type is {}".format(type))

# Check if there is an existing database

try:

print ("Opening existing database.")

DATABASE = db.DB()

DATABASE.open(DB_FILE)

# Database should not exist, if you hit this something is wrong

eg.msgbox("Reaching this box should be impossible")

except:

# Create a database based on type

DATABASE = db.DB()

print ("Database doesn't exist. Creating a new one.")

if "BTREE" in type or "btree" in type or "indexfile" in type:

DATABASE.open(DB_FILE, None, db.DB_BTREE, db.DB_CREATE)

if "indexfile" in type or "IndexFile" in type:

SEC_DB = db.DB()

SEC_DB.open(SDB_FILE, None, db.DB_BTREE, db.DB_CREATE)

eg.msgbox("Creating Indexed Database. Please wait.")

else:

print("btree database created")

eg.msgbox("Creating Btree Database. Please wait.")

elif "HASH" in type or "hash" in type:

DATABASE.open(DB_FILE, None, db.DB_HASH, db.DB_CREATE)

eg.msgbox("Creating Hash Table Database. Please wait.")

else:

eg.msgbox("Invalid type on execution, format should be ./mydbtest.py btree or hash or indexfile")

return

# This is taken from python example shown in lab, with changes for python3

# Add records to the database

lib.set_seed(SEED)

#for index in range(DB_SIZE):

index = 1

while index <= DB_SIZE:

krng = 64 + (lib.get_random() % 64)

key = ""

for i in range(krng):

key = key + str(chr(lib.get_random_char()))

vrng = 64 + (lib.get_random() % 64)

value = ""

for i in range(vrng):

value = value + str(chr(lib.get_random_char()))

# Change the string into bytes.

key = key.encode('utf-8')

value = value.encode('utf-8')

# Add key,value pair to database only if key is unique.

if (DATABASE.exists(key) == False):

DATABASE.put(key,value)

if "indexfile" in type:

SEC_DB.put(value, key)

else:

while (DATABASE.exists(key) == True):

print(key.decode('utf-8'), "cannot be added as it is a duplicate.")

krng = 64 + (lib.get_random() % 64)

key = ""

for i in range(krng):

key = key + str(chr(lib.get_random_char()))

key = key.encode('utf-8')

if "indexfile" in type:

SEC_DB.put(value, key)

DATABASE.put(key,value)

index = index + 1

if "indexfile" in type:

SEC_DB.close()

print("Length of Database: ", len(DATABASE))

DATABASE.close()

"""

Retrieve records with a given key.

"""

msg = "Please enter the key you wish to search for"

title = "Retrieve data with given key"

searchkey = eg.enterbox(msg, title)

if searchkey == None:

eg.msgbox("Operation cancelled.")

return

# >>>> Enable the following 2 lines for testing: <<<<<<

# searchkey = Testing(1)

# print (searchkey)

# Change the key from string to bytes:

bytes_key = searchkey.encode('utf-8')

# Run the query, taking time before and after.

time_before = time.time()

data = cur.set(bytes_key)

time_after = time.time()

# Get time in microseconds

runtime = (time_after - time_before) * 1000000

# Results found

if (data):

# Get the data portion of the <key,data> pair

strdata = data[1]

# Convert from bytes to a string.

strdata = strdata.decode('utf-8')

# Append to answers file.

answers.write(searchkey)

answers.write('\n')

answers.write(strdata)

answers.write('\n')

answers.write('\n')

text = ("Key input: \n{} \nData value found: \n{} \nNumber of records retrieved: 1 \nTime: {} microseconds.".format(searchkey, strdata, runtime))

# No results

else:

text = ("No results found for the following key: \n{} \nNumber of records retrieved: 0 \nTime: {} microseconds".format(searchkey, runtime))

msg = "Results:"

title = "Retrieve With Key"

"""

Retrieve records with a given range when database type is hash.

Just a proof of concept, doesn't return anything readable or write to the

answer file yet, but it does work.

"""

# Take input values

msg = "Please enter the range search key values."

title = "Ranged Search"

fieldNames = ["Lower Bound", "Upper Bound"]

fieldValues = []

fieldValues = eg.multenterbox(msg, title, fieldNames)

if fieldValues == None:

eg.msgbox('Operation cancelled')

return

lowerKey = fieldValues[0]

upperKey = fieldValues[1]

# Check that lower key < upper key.

if upperKey <= lowerKey:

eg.msgbox("Error! Upper bound must be larger than lower bound.")

return

# Change the key from string to bytes:

lowbyte_key = lowerKey.encode('utf-8')

upperbyte_key = upperKey.encode('utf-8')

current = cur.first()

# Iterate through the database, taking time before and after

resultlist = []

i = 0

time_before = time.time()

while i < len(DATABASE):

if lowbyte_key <= current[0] <= upperbyte_key:

resultlist.append((current[0], current[1]))

current = cur.next()

i += 1

time_after = time.time()

# Get time in microseconds

runtime = (time_after - time_before) * 1000000

# Results found

if (resultlist):

for item in resultlist:

answers.write(item[0].decode('utf-8'))

answers.write('\n')

answers.write(item[1].decode('utf-8'))

answers.write('\n')

answers.write('\n')

else:

text = ("No results found for the following key range:\n{}\n{}\nTime: {} microseconds".format(lowerKey, upperKey, runtime))

msg = "Results:"

title = "Retrieve With Key"

"""

Retrieve records with a given data

"""

msg = "Please enter the data you would like to search for"

title = "Retrieve key with given data"

searchdata = eg.enterbox(msg, title)

if searchdata == None:

eg.msgbox("Operation cancelled.")

return

# Change the data from string to bytes:

bytes_data = searchdata.encode('utf-8')

time_before = time.time()

first = cur.first()

data = first[1]

i = 1

while data != bytes_data and i < len(DATABASE):

next_record = cur.next()

data = next_record[1]

i += 1

if data == bytes_data:

key = next_record[0]

else:

key = 0

time_after = time.time()

# Get time in microseconds

runtime = (time_after - time_before) * 1000000

# Results found

if (key):

# Open answers file.

answers = open('answers','a')

# Convert from bytes to a string.

key = key.decode('utf-8')

# Append to answers file.

answers.write(key)

answers.write('\n')

answers.write(searchdata)

answers.write('\n')

answers.write('\n')

text = ("Data input: \n{} \nKey value found: \n{} \nNumber of records retrieved: 1 \nTime: {} microseconds.".format(searchdata, key, runtime))

# No results

else:

text = ("No results found for the following data: \n{} \nNumber of records retrieved: 0 \nTime: {} microseconds".format(searchdata, runtime))

msg = "Results:"

title = "Retrieve With Data"

"""

Retrieve records with a given range of key values

"""

msg = "Please enter the range search key values."

title = "Ranged Search"

fieldNames = ["Lower Bound", "Upper Bound"]

fieldValues = []

fieldValues = eg.multenterbox(msg, title, fieldNames)

if fieldValues == None:

eg.msgbox('Operation cancelled')

return

lowerKey = fieldValues[0]

upperKey = fieldValues[1]

# Check that lower key < upper key.

if upperKey <= lowerKey:

eg.msgbox("Error! Upper bound must be larger than lower bound.")

return

print("Lower Key: ",lowerKey)

print("Upper Key: ",upperKey)

time_before = time.time()

# Get the next key that is greater than lowerKey or equal to it.

# cur.set_range returns the key,data pair. Key is at 0th index.

tempPair = (cur.set_range(lowerKey.encode('utf-8')))

# Check if there are no results

if (tempPair == None):

time_after = time.time()

# Get the runtime in microseconds

runtime = (time_after - time_before) * 1000000

text = ("No results found in the following range: \nLower Bound: {} \nUpper Bound: {} \nNumber of records retrieved: 0 \nTime: {} microseconds".format(lowerKey, upperKey, runtime))

else:

tempKey = tempPair[0]

tempData = tempPair[1]

tempKey = tempKey.decode('utf-8')

tempData = tempData.decode('utf-8')

# Create a list to hold all keys found by range search

rangeResults = []

# Continue getting keys until 1 is larger than the upperKey.

while tempKey <= upperKey:

# Add to results

rangeResults.append((tempKey, tempData))

# Append to answers file.

answers.write(tempKey)

answers.write('\n')

answers.write(tempData)

answers.write('\n')

answers.write('\n')

# Get the next pair.

tempPair = (cur.next())

tempKey = tempPair[0]

tempData = tempPair[1]

tempKey = tempKey.decode('utf-8')

tempData = tempData.decode('utf-8')

time_after = time.time()

# Get the runtime in microseconds

runtime = (time_after - time_before) * 1000000

numResults = len(rangeResults)

text = ("Data input: \nLower Bound: {} \nUpper Bound: {} \nNumber of records retrieved: {} \nTime: {} microseconds \nRecords found: \n{}".format(lowerKey, upperKey, numResults, runtime, rangeResults))

msg = "Results:"

title = "Retrieve With Data"

eg.textbox(msg, title, text)

"""

Destroy the database

"""

# Close the existing database handle.

DATABASE.close()

try:

SEC_DB.close()

except:

pass

# Open a new database handle and drop the database.

db_destroy = db.DB()

if "indexfile" in sys.argv: sec_destroy = db.DB()

try:

db_destroy.remove(DB_FILE)

if "indexfile" in sys.argv: sec_destroy.remove(SDB_FILE)

eg.msgbox("Database was successfully dropped.")

db_destroy.close()

except Exception as e:

eg.msgbox("Database has already been dropped")

"""

Get a random key or data value from the database.

This is for testing the queries.

** If you want a random key val_type = 1.

If you want a random data value val_type = 2.

"""

# Get all pairs in database and add them to a list.

all_pairs = []

iter = cur.first()

while iter:

all_pairs.append(iter)

iter = cur.next()

# Get a random pair from the list.

index = random.randint(0, (len(all_pairs)-1))

random_pair = all_pairs[index]

# Get the key or data part.

if val_type == 1:

random_key = random_pair[0]

# Decode back to a string.

random_key = random_key.decode('utf-8')

return random_key

elif val_type == 2:

random_data = random_pair[1]

# Decode back to a string.

random_data = random_data.decode('utf-8')

return random_data

else:

# Should never be in here.