borg/src/borg/testsuite/hashindex_pytest.py

76 lines
2.5 KiB
Python

# more hashindex tests. kept separate so we can use pytest here.
import os
import random
import pytest
from ..hashindex import NSIndex
def verify_hash_table(kv, idx):
"""kv should be a python dictionary and idx an NSIndex. Check that idx
has the expected entries and the right number of entries.
"""
for k, v in kv.items():
assert k in idx and idx[k] == (v, v, v)
assert len(idx) == len(kv)
def make_hashtables(*, entries, loops):
idx = NSIndex()
kv = {}
for i in range(loops):
# put some entries
for j in range(entries):
k = random.randbytes(32)
v = random.randint(0, NSIndex.MAX_VALUE - 1)
idx[k] = (v, v, v)
kv[k] = v
# check and delete a random amount of entries
delete_keys = random.sample(list(kv), k=random.randint(0, len(kv)))
for k in delete_keys:
v = kv.pop(k)
assert idx.pop(k) == (v, v, v)
verify_hash_table(kv, idx)
return idx, kv
@pytest.mark.skipif("BORG_TESTS_SLOW" not in os.environ, reason="slow tests not enabled, use BORG_TESTS_SLOW=1")
def test_hashindex_stress():
"""checks if the hashtable behaves as expected
This can be used in _hashindex.c before running this test to provoke more collisions (don't forget to compile):
#define HASH_MAX_LOAD .99
#define HASH_MAX_EFF_LOAD .999
"""
make_hashtables(entries=10000, loops=1000) # we do quite some assertions while making them
def test_hashindex_compact():
"""test that we do not lose or corrupt data by the compaction nor by expanding/rebuilding"""
idx, kv = make_hashtables(entries=5000, loops=5)
size_noncompact = idx.size()
# compact the hashtable (remove empty/tombstone buckets)
saved_space = idx.compact()
# did we actually compact (reduce space usage)?
size_compact = idx.size()
assert saved_space > 0
assert size_noncompact - size_compact == saved_space
# did we lose anything?
verify_hash_table(kv, idx)
# now expand the hashtable again. trigger a resize/rebuild by adding an entry.
k = b"x" * 32
idx[k] = (0, 0, 0)
kv[k] = 0
size_rebuilt = idx.size()
assert size_rebuilt > size_compact + 1
# did we lose anything?
verify_hash_table(kv, idx)
@pytest.mark.skipif("BORG_TESTS_SLOW" not in os.environ, reason="slow tests not enabled, use BORG_TESTS_SLOW=1")
def test_hashindex_compact_stress():
for _ in range(100):
test_hashindex_compact()