def test_with_cache(blobs_digests):
blobs, digests = blobs_digests
blob1, blob2, blob3, *_ = blobs
digest1, digest2, digest3, *_ = digests
cache = LRUMemoryCache(256)
fallback = LRUMemoryCache(256)
with_cache_storage = WithCacheStorage(cache, fallback)
assert not with_cache_storage.has_blob(digest1)
write(with_cache_storage, digest1, blob1)
assert cache.has_blob(digest1)
assert fallback.has_blob(digest1)
assert with_cache_storage.get_blob(digest1).read() == blob1
# Even if a blob is in cache, we still need to check if the fallback
# has it.
write(cache, digest2, blob2)
assert not with_cache_storage.has_blob(digest2)
write(fallback, digest2, blob2)
assert with_cache_storage.has_blob(digest2)
# When a blob is in the fallback but not the cache, reading it should
# put it into the cache.
write(fallback, digest3, blob3)
assert with_cache_storage.get_blob(digest3).read() == blob3
assert cache.has_blob(digest3)
assert cache.get_blob(digest3).read() == blob3
assert cache.has_blob(digest3)
def test_lru_eviction(blobs_digests):
blobs, digests = blobs_digests
blob1, blob2, blob3, *_ = blobs
digest1, digest2, digest3, *_ = digests
lru = LRUMemoryCache(8)
write(lru, digest1, blob1)
write(lru, digest2, blob2)
assert lru.has_blob(digest1)
assert lru.has_blob(digest2)
write(lru, digest3, blob3)
# Check that the LRU evicted blob1 (it was written first)
assert not lru.has_blob(digest1)
assert lru.has_blob(digest2)
assert lru.has_blob(digest3)
assert lru.get_blob(digest2).read() == blob2
write(lru, digest1, blob1)
# Check that the LRU evicted blob3 (since we just read blob2)
assert lru.has_blob(digest1)
assert lru.has_blob(digest2)
assert not lru.has_blob(digest3)
assert lru.has_blob(digest2)
write(lru, digest3, blob1)
# Check that the LRU evicted blob1 (since we just checked blob3)
assert not lru.has_blob(digest1)
assert lru.has_blob(digest2)
assert lru.has_blob(digest3)