Hmm, it seems my implementation is 30% slower when many mishit scenario.
Maybe, dict is faster than OrderedDict about massive insert/discard.  But I need to profile it.

On the other hand, GC speed looks about 2x faster as expected.

$ ./python -m perf compare_to master.json patched.json  -G
Slower (5):
- lru_1000_100: 217 ns +- 6 ns -> 302 ns +- 6 ns: 1.39x slower (+39%)
- lru_10000_1000: 225 ns +- 4 ns -> 309 ns +- 2 ns: 1.37x slower (+37%)
- lru_100_1000: 114 ns +- 5 ns -> 119 ns +- 1 ns: 1.05x slower (+5%)
- lru_100_100: 115 ns +- 6 ns -> 119 ns +- 1 ns: 1.03x slower (+3%)
- lru_1000_1000: 134 ns +- 6 ns -> 136 ns +- 1 ns: 1.02x slower (+2%)

Faster (4):
- gc(1000000): 98.3 ms +- 0.3 ms -> 37.9 ms +- 0.2 ms: 2.59x faster (-61%)
- gc(100000): 11.7 ms +- 0.0 ms -> 5.10 ms +- 0.02 ms: 2.29x faster (-56%)
- gc(10000): 1.48 ms +- 0.02 ms -> 1.04 ms +- 0.01 ms: 1.41x faster (-29%)
- lru_10_100: 149 ns +- 6 ns -> 147 ns +- 2 ns: 1.02x faster (-2%)