Now use the routing to actually store data. Each shard is its own little dict; a key only ever lives in the one shard that owns it.
put(key, value): store the pair in the key's shardget(key): read the value from the key's shard, or None if it's not thereclass ShardedDB:
def __init__(self, num_shards):
self.num_shards = num_shards
self.shards = [dict() for _ in range(num_shards)]
def _hash(self, key):
h = 0
for ch in str(key):
h = (h * 31 + ord(ch)) & 0xffffffff
return h
def _shard_for(self, key):
return self._hash(key) % self.num_shards
def put(self, key, value):
"""Store the pair in the shard that owns the key."""
# TODO: self.shards[self._shard_for(key)][key] = value
pass
def get(self, key):
"""Fetch the value from the shard that owns the key, or None."""
# TODO: return self.shards[self._shard_for(key)].get(key)
pass
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Now use the routing to actually store data. Each shard is its own little dict; a key only ever lives in the one shard that owns it.
put(key, value): store the pair in the key's shardget(key): read the value from the key's shard, or None if it's not therePress Run Tests or ⌘↩ to check your solution.