124 lines
3.4 KiB
Python
124 lines
3.4 KiB
Python
import hashlib
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import bisect
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import xxhash
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def hash_str(s):
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xxh = xxhash.xxh64()
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xxh.update(s.encode('ascii'))
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return xxh.hexdigest()
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def sha256_str(s):
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return hashlib.sha256(s.encode('ascii')).hexdigest()
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def walk_ring_from_pos(tokens, dcs, start, rep):
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ret = []
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ret_dcs = set()
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delta = 0
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while len(ret) < rep:
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i = (start + delta) % len(tokens)
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delta = delta + 1
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(token_k, token_dc, token_node) = tokens[i]
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if token_dc not in ret_dcs:
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ret_dcs |= set([token_dc])
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ret.append(token_node)
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elif len(ret_dcs) == len(dcs) and token_node not in ret:
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ret.append(token_node)
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return ret
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def count_tokens_per_node(tokens):
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tokens_of_node = {}
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for _, _, token_node in tokens:
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if token_node not in tokens_of_node:
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tokens_of_node[token_node] = 0
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tokens_of_node[token_node] += 1
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print("#tokens per node:")
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for node, ntok in sorted(list(tokens_of_node.items())):
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print(node, ": ", ntok)
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def method1(nodes):
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tokens = []
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dcs = set()
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for (node_id, dc, n_tokens) in nodes:
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dcs |= set([dc])
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for i in range(n_tokens):
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token = hash_str(f"{node_id} {i}")
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tokens.append((token, dc, node_id))
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tokens.sort(key=lambda tok: tok[0])
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print(tokens)
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count_tokens_per_node(tokens)
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space_of_node = {}
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def walk_ring(v, rep):
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i = bisect.bisect_left([tok for tok, _, _ in tokens], hash_str(v))
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return walk_ring_from_pos(tokens, dcs, i, rep)
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return walk_ring
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def method2(nodes):
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partition_bits = 10
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partitions = list(range(2**partition_bits))
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def partition_node(i):
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h, hn, hndc = None, None, None
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for (node_id, node_dc, n_tokens) in nodes:
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for tok in range(n_tokens):
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hnode = hash_str(f"partition {i} node {node_id} token {tok}")
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if h is None or hnode < h:
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h = hnode
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hn = node_id
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hndc = node_dc
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return (i, hndc, hn)
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partition_nodes = [partition_node(i) for i in partitions]
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count_tokens_per_node(partition_nodes)
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dcs = list(set(node_dc for _, node_dc, _ in nodes))
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def walk_ring(v, rep):
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xxh = xxhash.xxh32()
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xxh.update(v.encode('ascii'))
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vh = xxh.intdigest()
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i = vh % (2**partition_bits)
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return walk_ring_from_pos(partition_nodes, dcs, i, rep)
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return walk_ring
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def evaluate_method(walk_ring):
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node_data_counts = {}
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for i in range(100000):
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nodes = walk_ring(f"{i}", 3)
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for n in nodes:
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if n not in node_data_counts:
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node_data_counts[n] = 0
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node_data_counts[n] += 1
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print("Number of data items per node:")
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for n, v in sorted(list(node_data_counts.items())):
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print(n, ": ", v)
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if __name__ == "__main__":
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print("------")
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print("method 1")
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nodes = [('digitale', 'atuin', 64),
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('drosera', 'atuin', 64),
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('datura', 'atuin', 64),
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('io', 'jupiter', 128)]
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method1_walk_ring = method1(nodes)
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evaluate_method(method1_walk_ring)
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print("------")
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print("method 2")
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nodes = [('digitale', 'atuin', 10),
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('drosera', 'atuin', 10),
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('datura', 'atuin', 10),
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('io', 'jupiter', 20)]
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method2_walk_ring = method2(nodes)
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evaluate_method(method2_walk_ring)
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