Files
sglang/test/registered/unit/mem_cache/test_evict_policy.py
2026-03-23 00:18:45 -07:00

219 lines
7.6 KiB
Python

"""Unit tests for evict_policy.py"""
from sglang.test.ci.ci_register import register_cpu_ci
register_cpu_ci(est_time=5, suite="stage-a-test-cpu")
import unittest
from unittest.mock import MagicMock
from sglang.srt.mem_cache.evict_policy import (
FIFOStrategy,
FILOStrategy,
LFUStrategy,
LRUStrategy,
MRUStrategy,
PriorityStrategy,
SLRUStrategy,
)
def _make_node(**kwargs):
node = MagicMock()
node.last_access_time = kwargs.get("last_access_time", 0.0)
node.hit_count = kwargs.get("hit_count", 0)
node.creation_time = kwargs.get("creation_time", 0.0)
node.priority = kwargs.get("priority", 0)
return node
class TestLRUStrategy(unittest.TestCase):
def setUp(self):
self.strategy = LRUStrategy()
def test_priority_is_last_access_time(self):
node = _make_node(last_access_time=42.0)
self.assertEqual(self.strategy.get_priority(node), 42.0)
def test_older_access_evicted_first(self):
old = _make_node(last_access_time=1.0)
new = _make_node(last_access_time=10.0)
self.assertLess(
self.strategy.get_priority(old), self.strategy.get_priority(new)
)
class TestLFUStrategy(unittest.TestCase):
def setUp(self):
self.strategy = LFUStrategy()
def test_priority_is_hit_count_and_time(self):
node = _make_node(hit_count=5, last_access_time=3.0)
self.assertEqual(self.strategy.get_priority(node), (5, 3.0))
def test_lower_hit_count_evicted_first(self):
cold = _make_node(hit_count=1, last_access_time=10.0)
hot = _make_node(hit_count=100, last_access_time=1.0)
self.assertLess(
self.strategy.get_priority(cold), self.strategy.get_priority(hot)
)
def test_same_hit_count_older_access_evicted_first(self):
old = _make_node(hit_count=3, last_access_time=1.0)
new = _make_node(hit_count=3, last_access_time=10.0)
self.assertLess(
self.strategy.get_priority(old), self.strategy.get_priority(new)
)
class TestFIFOStrategy(unittest.TestCase):
def setUp(self):
self.strategy = FIFOStrategy()
def test_priority_is_creation_time(self):
node = _make_node(creation_time=7.0)
self.assertEqual(self.strategy.get_priority(node), 7.0)
def test_earlier_created_evicted_first(self):
first = _make_node(creation_time=1.0)
second = _make_node(creation_time=5.0)
self.assertLess(
self.strategy.get_priority(first), self.strategy.get_priority(second)
)
class TestMRUStrategy(unittest.TestCase):
def setUp(self):
self.strategy = MRUStrategy()
def test_priority_is_negated_access_time(self):
node = _make_node(last_access_time=5.0)
self.assertEqual(self.strategy.get_priority(node), -5.0)
def test_most_recently_used_evicted_first(self):
"""MRU evicts the most recently accessed node first (lowest priority value)."""
old = _make_node(last_access_time=1.0)
new = _make_node(last_access_time=10.0)
self.assertLess(
self.strategy.get_priority(new), self.strategy.get_priority(old)
)
class TestFILOStrategy(unittest.TestCase):
def setUp(self):
self.strategy = FILOStrategy()
def test_priority_is_negated_creation_time(self):
node = _make_node(creation_time=3.0)
self.assertEqual(self.strategy.get_priority(node), -3.0)
def test_last_created_evicted_first(self):
"""FILO evicts the most recently created node first."""
first = _make_node(creation_time=1.0)
second = _make_node(creation_time=5.0)
self.assertLess(
self.strategy.get_priority(second), self.strategy.get_priority(first)
)
class TestPriorityStrategy(unittest.TestCase):
def setUp(self):
self.strategy = PriorityStrategy()
def test_priority_is_tuple(self):
node = _make_node(priority=2, last_access_time=4.0)
self.assertEqual(self.strategy.get_priority(node), (2, 4.0))
def test_lower_priority_evicted_first(self):
low = _make_node(priority=1, last_access_time=10.0)
high = _make_node(priority=5, last_access_time=1.0)
self.assertLess(
self.strategy.get_priority(low), self.strategy.get_priority(high)
)
def test_same_priority_older_access_evicted_first(self):
old = _make_node(priority=3, last_access_time=1.0)
new = _make_node(priority=3, last_access_time=10.0)
self.assertLess(
self.strategy.get_priority(old), self.strategy.get_priority(new)
)
class TestSLRUStrategy(unittest.TestCase):
def setUp(self):
self.strategy = SLRUStrategy(protected_threshold=2)
def test_probationary_segment(self):
node = _make_node(hit_count=1, last_access_time=5.0)
self.assertEqual(self.strategy.get_priority(node), (0, 5.0))
def test_protected_segment(self):
node = _make_node(hit_count=2, last_access_time=5.0)
self.assertEqual(self.strategy.get_priority(node), (1, 5.0))
def test_highly_accessed_is_protected(self):
node = _make_node(hit_count=100, last_access_time=5.0)
self.assertEqual(self.strategy.get_priority(node), (1, 5.0))
def test_probationary_evicted_before_protected(self):
prob = _make_node(hit_count=1, last_access_time=10.0)
prot = _make_node(hit_count=5, last_access_time=1.0)
self.assertLess(
self.strategy.get_priority(prob), self.strategy.get_priority(prot)
)
def test_same_segment_older_access_evicted_first(self):
old = _make_node(hit_count=0, last_access_time=1.0)
new = _make_node(hit_count=0, last_access_time=10.0)
self.assertLess(
self.strategy.get_priority(old), self.strategy.get_priority(new)
)
def test_custom_threshold(self):
strategy = SLRUStrategy(protected_threshold=5)
below = _make_node(hit_count=4, last_access_time=1.0)
at = _make_node(hit_count=5, last_access_time=1.0)
self.assertEqual(strategy.get_priority(below), (0, 1.0))
self.assertEqual(strategy.get_priority(at), (1, 1.0))
def test_default_threshold_is_2(self):
default = SLRUStrategy()
self.assertEqual(default.protected_threshold, 2)
class TestEvictionOrdering(unittest.TestCase):
"""Integration-style test: sort a list of nodes by eviction priority."""
def test_lru_ordering(self):
strategy = LRUStrategy()
nodes = [
_make_node(last_access_time=5.0),
_make_node(last_access_time=1.0),
_make_node(last_access_time=3.0),
]
eviction_order = sorted(nodes, key=strategy.get_priority)
times = [n.last_access_time for n in eviction_order]
self.assertEqual(times, [1.0, 3.0, 5.0])
def test_slru_ordering(self):
strategy = SLRUStrategy(protected_threshold=2)
nodes = [
_make_node(hit_count=5, last_access_time=1.0), # protected, old
_make_node(hit_count=0, last_access_time=10.0), # probationary, new
_make_node(hit_count=0, last_access_time=2.0), # probationary, old
_make_node(hit_count=3, last_access_time=8.0), # protected, new
]
eviction_order = sorted(nodes, key=strategy.get_priority)
expected = [
(0, 2.0), # probationary old
(0, 10.0), # probationary new
(1, 1.0), # protected old
(1, 8.0), # protected new
]
actual = [strategy.get_priority(n) for n in eviction_order]
self.assertEqual(actual, expected)
if __name__ == "__main__":
unittest.main()