Copy async_lru for Python 3.7 compatibility

tests/external/test_cache_invalidate.py

@@ -0,0 +1,85 @@
+import asyncio
+
+import pytest
+from great_ai.external.async_lru import alru_cache
+
+pytestmark = pytest.mark.asyncio
+
+
+async def test_cache_invalidate(check_lru, loop):
+    @alru_cache()
+    async def coro(val):
+        return val
+
+    inputs = [1, 2, 3]
+
+    coro.invalidate(1)
+    coro.invalidate(2)
+    coro.invalidate(3)
+
+    coros = [coro(v) for v in inputs]
+
+    ret = await asyncio.gather(*coros)
+
+    assert ret == inputs
+    check_lru(coro, hits=0, misses=3, cache=3, tasks=0)
+
+    coro.invalidate(1)
+    check_lru(coro, hits=0, misses=3, cache=2, tasks=0)
+    coro.invalidate(2)
+    check_lru(coro, hits=0, misses=3, cache=1, tasks=0)
+    coro.invalidate(3)
+    check_lru(coro, hits=0, misses=3, cache=0, tasks=0)
+
+    inputs = [1, 2, 3]
+    coros = [coro(v) for v in inputs]
+
+    ret = await asyncio.gather(*coros)
+
+    assert ret == inputs
+    check_lru(coro, hits=0, misses=6, cache=3, tasks=0)
+
+
+async def test_cache_invalidate_multiple_args(check_lru, loop):
+    @alru_cache()
+    async def coro(*args):
+        return len(args)
+
+    for i, size in enumerate(range(10)):
+        args = tuple(range(size))
+        ret = await coro(*args)
+        assert ret == size
+        check_lru(coro, hits=0, misses=i + 1, cache=1, tasks=0)
+        coro.invalidate(*args)
+        check_lru(coro, hits=0, misses=i + 1, cache=0, tasks=0)
+
+    for size in range(10):
+        args = tuple(range(size))
+        ret = await coro(*args)
+        assert ret == size
+    check_lru(coro, hits=0, misses=20, cache=10, tasks=0)
+
+
+async def test_cache_invalidate_multiple_args_different_order(check_lru, loop):
+    @alru_cache()
+    async def coro(*args):
+        return len(args)
+
+    for i, size in enumerate(range(2, 10)):
+        args = tuple(range(size))
+        rev_args = tuple(reversed(args))
+        ret = await coro(*args)
+        assert ret == size
+        check_lru(coro, hits=0, misses=2 * i + 1, cache=i + 1, tasks=0)
+        ret = await coro(*rev_args)
+        # The reversed args should be a miss
+        check_lru(coro, hits=0, misses=2 * i + 2, cache=i + 2, tasks=0)
+        coro.invalidate(*rev_args)
+        # The reversed args should be invalidated
+        check_lru(coro, hits=0, misses=2 * i + 2, cache=i + 1, tasks=0)
+
+    for i, size in enumerate(range(2, 10)):
+        args = tuple(range(size))
+        ret = await coro(*args)
+        assert ret == size
+        check_lru(coro, hits=i + 1, misses=16, cache=8, tasks=0)