| """Bounded, expiring CPU transcript cache; never retains audio or CUDA objects.""" |
|
|
| import hashlib |
| import time |
| from collections import OrderedDict |
| from threading import Lock |
|
|
|
|
| class TranscriptCache: |
| def __init__(self, max_entries=16, ttl_seconds=600, clock=time.monotonic): |
| self.max_entries = max_entries |
| self.ttl_seconds = ttl_seconds |
| self.clock = clock |
| self.entries = OrderedDict() |
| self.lock = Lock() |
|
|
| @staticmethod |
| def key(waveform, settings): |
| digest = hashlib.sha256() |
| digest.update(repr((waveform.shape, waveform.dtype.str, settings)).encode()) |
| digest.update(waveform.tobytes()) |
| return digest.digest() |
|
|
| def _expire(self, now): |
| for key, (expires, _) in list(self.entries.items()): |
| if expires <= now: |
| del self.entries[key] |
|
|
| def get(self, key): |
| with self.lock: |
| self._expire(self.clock()) |
| entry = self.entries.get(key) |
| if entry is None: |
| return None |
| self.entries.move_to_end(key) |
| return entry[1] |
|
|
| def put(self, key, value): |
| with self.lock: |
| now = self.clock() |
| self._expire(now) |
| self.entries[key] = (now + self.ttl_seconds, value) |
| self.entries.move_to_end(key) |
| while len(self.entries) > self.max_entries: |
| self.entries.popitem(last=False) |
|
|
