def search_run(size):
# Create an Skip List
sl = SkipList()
# Insert elements
for i in xrange(size):
sl.insert(i)
# Now, get time
start = time.clock()
# Find elements
for i in xrange(size):
sl.find(size)
# Get final time, and store
end = time.clock()
return {
'structure': 'skip_list',
'size': size,
'time': end - start,
'comparisons': sl.comparisons,
'height': sl.maxHeight
}
class TestSkipList:
def setup(self):
self.skip_list = SkipList()
def test_root(self):
self.skip_list.append(3)
eq_(self.skip_list.root.val(), 3)
eq_(len(self.skip_list), 1)
eq_(self.skip_list.root, self.skip_list.last)
def test_append(self):
self.skip_list.append(1)
self.skip_list.append(2)
self.skip_list.append(3)
self.skip_list.append(4)
eq_(self.skip_list.root.val(), 1)
eq_(len(self.skip_list), 4)
eq_(self.skip_list.last.val(), 4)
def test_generate_skips(self):
for i in range(30):
self.skip_list.append(i)
skip_pairs = [(a, b) for (a, b) in self.skip_list.generate_skips()]
eq_(skip_pairs, [(1, 6), (6, 11), (11, 16), (16, 21), (21, 26)])
def build_dictionary(terms, dictionary, doc_id, postings):
"""Build a dictionary and respective postings list from the terms"""
global pointer
for term in terms:
if term not in dictionary:
skip_list = SkipList()
skip_list.append(doc_id)
dictionary[term] = [len(skip_list), pointer]
postings.insert(pointer, skip_list)
else:
pointer = dictionary[term][1]
postings[dictionary[term][1]].append(doc_id)
dictionary[term][0] += 1
pointer += 1
def build_dictionary(terms, dictionary, doc_id, postings):
"""Build a dictionary and respective postings list from the terms"""
global pointer
for term in terms:
if term not in dictionary:
skip_list = SkipList()
skip_list.append(doc_id)
dictionary[term] = [len(skip_list), pointer]
postings.insert(pointer, skip_list)
else:
pointer = dictionary[term][1]
postings[dictionary[term][1]].append(doc_id)
dictionary[term][0] += 1
pointer += 1
def main(): sl = SkipList() sl.set(1, 1) sl.set(2, 2) sl.set(4, 4) sl.set(3, 3) sl.set(6, 6) sl.set(5, 5) print_skip_list(sl) sl.remove(3) print_skip_list(sl) print(sl.at(4))
def test():
skip_list = SkipList()
items = list(range(NUMBER_OF_ITEMS))
for item in items:
skip_list.insert(item)
# Runs the experiment on the original skip list.
skip_times = [0 for i in items]
for i in range(NUMBER_OF_RUNS):
for item in items:
start = time.time() * 1000
skip_list.search(item)
end = time.time() * 1000
skip_times[item] += (end - start) / NUMBER_OF_RUNS
mean_skip_time = sum(skip_times) / len(skip_times)
std_dev_skip_time = math.sqrt(sum([(mean_skip_time - t)**2 for t in skip_times]))
max_z_score_skip_time = (max(skip_times) - mean_skip_time) / std_dev_skip_time
print("Skip List Data: ")
print(skip_times)
print(mean_skip_time)
print(std_dev_skip_time)
print(max_z_score_skip_time)
# Runs the experiment on the TUSL.
tusl_list = TUSL(skip_list)
tusl_times = [0 for i in items]
for i in range(NUMBER_OF_RUNS):
for item in items:
start = time.time() * 1000
tusl_list.search(item)
end = time.time() * 1000
tusl_times[item] += (end-start) / NUMBER_OF_RUNS
mean_tusl_time = sum(tusl_times) / len(tusl_times)
std_dev_tusl_time = math.sqrt(sum([(mean_tusl_time - t) ** 2 for t in tusl_times]))
max_z_score_tusl_time = (max(tusl_times) - mean_tusl_time) / std_dev_tusl_time
print("TUSL Data: ")
print(tusl_times)
print(mean_tusl_time)
print(std_dev_tusl_time)
print(max_z_score_tusl_time)
# Creates charts showing the query times for each index.
fig1 = plt.figure(1, (12, 12))
plt.bar(items, skip_times)
fig2 = plt.figure(2, (12, 12))
plt.bar(items, tusl_times)
plt.show()
def setup(self):
self.skip_list = SkipList()
def main():
sl = SkipList()
sl.set(1, 1)
sl.set(2, 2)
sl.set(4, 4)
sl.set(3, 3)
sl.set(6, 6)
sl.set(5, 5)
print_skip_list(sl)
sl.remove(3)
print_skip_list(sl)
print(sl.at(4))