优化crc速度

tests/test_common.py

@@ -0,0 +1,27 @@
+"""Common codec utility tests."""
+import struct
+
+from go1_pro_sdk.utils.common import gen_crc
+
+
+def _gen_crc_bitwise(data: bytes) -> bytes:
+    crc = 0xFFFFFFFF
+    for (word,) in struct.iter_unpack("<I", data):
+        for bit in range(32):
+            x = (crc >> 31) & 1
+            crc <<= 1
+            crc &= 0xFFFFFFFF
+            if x ^ (1 & (word >> (31 - bit))):
+                crc ^= 0x04c11db7
+    return struct.pack("<I", crc)
+
+
+def test_gen_crc_matches_reference_bitwise():
+    samples = [
+        b"",
+        bytes(4),
+        bytes(range(64)),
+        b"\xfe\xef\xff\x00" + bytes(range(252)) * 2,
+    ]
+    for sample in samples:
+        assert gen_crc(sample) == _gen_crc_bitwise(sample)