Chord\u7b97\u6cd5<\/p>\n
P2P\u7684\u4e00\u4e2a\u5e38\u89c1\u95ee\u9898\u662f\u5982\u4f55\u9ad8\u6548\u7684\u5b9a\u4f4d\u8282\u70b9\uff0c\u4e5f\u5c31\u662f\u8bf4\uff0c\u4e00\u4e2a\u8282\u70b9\u600e\u6837\u9ad8\u6548\u7684\u77e5\u9053\u5728\u7f51\u7edc\u4e2d\u7684\u54ea\u4e2a\u8282\u70b9\u5305\u542b\u5b83\u6240\u5bfb\u627e\u7684\u6570\u636e\uff0c\u5982\u4e0b\u56fe\uff1a<\/p>\n
\n
\u5bf9\u6b64\uff0c\u6709\u4e09\u79cd\u6bd4\u8f83\u5178\u578b\u7684\u6765\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u3002<\/p>\n
Napster\uff1a\u4f7f\u7528\u4e00\u4e2a\u4e2d\u5fc3\u670d\u52a1\u5668\u63a5\u6536\u6240\u6709\u7684\u67e5\u8be2\uff0c\u670d\u52a1\u5668\u544a\u77e5\u53bb\u54ea\u4e0b\u8f7d\u5176\u6240\u9700\u8981\u7684\u6570\u636e\u3002\u5b58\u5728\u7684\u95ee\u9898\u662f\u4e2d\u5fc3\u670d\u52a1\u5668\u5355\u70b9\u5931\u6548\u5bfc\u81f4\u6574\u4e2a\u7f51\u7edc\u762b\u75ea\u3002<\/p>\n
\n
Gnutella\uff1a\u4f7f\u7528\u6d88\u606f\u6d2a\u6cdb\uff08message flooding\uff09\u6765\u5b9a\u4f4d\u6570\u636e\u3002\u4e00\u4e2a\u6d88\u606f\u88ab\u53d1\u5230\u7cfb\u7edf\u5185\u6bcf\u4e00\u4e2a\u8282\u70b9\uff0c\u76f4\u5230\u627e\u5230\u5176\u9700\u8981\u7684\u6570\u636e\u4e3a\u6b62\u3002\u5f53\u7136\uff0c\u4f7f\u7528\u751f\u5b58\u65f6\u95f4\uff08TTL\uff09\u6765\u9650\u5236\u7f51\u7edc\u5185\u8f6c\u53d1\u6d88\u606f\u7684\u6570\u91cf\u3002\u5b58\u5728\u7684\u95ee\u9898\u662f\u6d88\u606f\u6570\u4e0e\u8282\u70b9\u6570\u6210\u7ebf\u6027\u5173\u7cfb\uff0c\u5bfc\u81f4\u7f51\u7edc\u8d1f\u8f7d\u8f83\u91cd\u3002<\/p>\n
\n
SN\u578b\uff1a\u73b0\u5728\u5927\u591a\u6570\u91c7\u7528\u6240\u8c13\u8d85\u7ea7\u8282\u70b9\uff08Super Node\uff09\uff0cSN\u4fdd\u5b58\u7f51\u7edc\u4e2d\u8282\u70b9\u7684\u7d22\u5f15\u4fe1\u606f\uff0c\u8fd9\u4e00\u70b9\u548c\u4e2d\u5fc3\u670d\u52a1\u5668\u7c7b\u578b\u4e00\u6837\uff0c\u4f46\u662f\u7f51\u5185\u6709\u591a\u4e2aSN\uff0c\u5176\u7d22\u5f15\u4fe1\u606f\u4f1a\u5728\u8fd9\u4e9bSN\u4e2d\u8fdb\u884c\u4f20\u64ad\uff0c\u6240\u4ee5\u6574\u4e2a\u7cfb\u7edf\u7684\u5d29\u6e83\u51e0\u7387\u5c31\u4f1a\u5c0f\u5f88\u591a\u3002\u5c3d\u7ba1\u5982\u6b64\uff0c\u7f51\u7edc\u8fd8\u662f\u6709\u5d29\u6e83\u7684\u53ef\u80fd\u3002<\/p>\n
\u73b0\u5728\u7684\u7814\u7a76\u7ed3\u679c\u4e2d\uff0cChord\u3001Pastry\u3001CAN\u548cTapestry\u7b49\u5e38\u7528\u4e8e\u6784\u5efa\u7ed3\u6784\u5316P2P\u7684\u5206\u5e03\u5f0f\u54c8\u5e0c\u8868\u7cfb\u7edf\uff08Distributed Hash Table\uff0cDHT\uff09\u3002<\/p>\n
DHT\u7684\u4e3b\u8981\u601d\u60f3\u662f\uff1a\u9996\u5148\uff0c\u6bcf\u6761\u6587\u4ef6\u7d22\u5f15\u88ab\u8868\u793a\u6210\u4e00\u4e2a(K, V)\u5bf9\uff0cK\u79f0\u4e3a\u5173\u952e\u5b57\uff0c\u53ef\u4ee5\u662f\u6587\u4ef6\u540d\uff08\u6216\u6587\u4ef6\u7684\u5176\u4ed6\u63cf\u8ff0\u4fe1\u606f\uff09\u7684\u54c8\u5e0c\u503c\uff0cV\u662f\u5b9e\u9645\u5b58\u50a8\u6587\u4ef6\u7684\u8282\u70b9\u7684IP\u5730\u5740\uff08\u6216\u8282\u70b9\u7684\u5176\u4ed6\u63cf\u8ff0\u4fe1\u606f\uff09\u3002\u6240\u6709\u7684\u6587\u4ef6\u7d22\u5f15\u6761\u76ee(\u5373\u6240\u6709\u7684\uff08K, V\uff09\u5bf9)\u7ec4\u6210\u4e00\u5f20\u5927\u7684\u6587\u4ef6\u7d22\u5f15\u54c8\u5e0c\u8868\uff0c\u53ea\u8981\u8f93\u5165\u76ee\u6807\u6587\u4ef6\u7684K\u503c\uff0c\u5c31\u53ef\u4ee5\u4ece\u8fd9\u5f20\u8868\u4e2d\u67e5\u51fa\u6240\u6709\u5b58\u50a8\u8be5\u6587\u4ef6\u7684\u8282\u70b9\u5730\u5740\u3002\u7136\u540e\uff0c\u518d\u5c06\u4e0a\u9762\u7684\u5927\u6587\u4ef6\u54c8\u5e0c\u8868\u5206\u5272\u6210\u5f88\u591a\u5c40\u90e8\u5c0f\u5757\uff0c\u6309\u7167\u7279\u5b9a\u7684\u89c4\u5219\u628a\u8fd9\u4e9b\u5c0f\u5757\u7684\u5c40\u90e8\u54c8\u5e0c\u8868\u5206\u5e03\u5230\u7cfb\u7edf\u4e2d\u7684\u6240\u6709\u53c2\u4e0e\u8282\u70b9\u4e0a\uff0c\u4f7f\u5f97\u6bcf\u4e2a\u8282\u70b9\u8d1f\u8d23\u7ef4\u62a4\u5176\u4e2d\u7684\u4e00\u5757\u3002\u8fd9\u6837\uff0c\u8282\u70b9\u67e5\u8be2\u6587\u4ef6\u65f6\uff0c\u53ea\u8981\u628a\u67e5\u8be2\u62a5\u6587\u8def\u7531\u5230\u76f8\u5e94\u7684\u8282\u70b9\u5373\u53ef\uff08\u8be5\u8282\u70b9\u7ef4\u62a4\u7684\u54c8\u5e0c\u8868\u5206\u5757\u4e2d\u542b\u6709\u8981\u67e5\u627e\u7684(K,V)\u5bf9\uff09\u3002<\/p>\n
\u8fd9\u91cc\u4ecb\u7ecd\u7684Chord\u7b97\u6cd5\u5c31\u662f\u89e3\u51b3\u7f51\u7edc\u5185\u8282\u70b9\u5b9a\u4f4d\u95ee\u9898\u7684\u4e00\u79cdP2P\u534f\u8bae\u3002\u5b83\u901a\u8fc7\u591a\u4e2a\u8282\u70b9\u8df3\u8f6c\u627e\u5230\u6211\u4eec\u6240\u67e5\u627e\u7684\u8d44\u6e90\uff1a<\/p>\n
\n
\u6211\u4eec\u5148\u770b\u770b\u5b83\u662f\u5982\u4f55\u8fdb\u884c\u7684\uff0c\u968f\u540e\u518d\u603b\u7ed3\u5176\u7279\u70b9\u548c\u64cd\u4f5c\u7279\u5f81\uff0c\u4ee5\u53ca\u4e00\u4e9b\u5b9e\u73b0\u3002<\/p>\n
1.Chord\u91cc\u9762\u7684\u57fa\u672c\u8981\u7d20<\/strong><\/p>\n \u8282\u70b9ID\uff1aNID\uff08node identifier\uff09\uff0c\u8868\u793a\u4e00\u4e2a\u7269\u7406\u673a\u5668\uff0cm\u4f4d\u7684\u4e00\u4e2a\u6570\u5b57\uff08m\u8981\u8db3\u591f\u5927\u4ee5\u4fdd\u8bc1\u4e0d\u540c\u8282\u70b9\u7684NID\u76f8\u540c\u7684\u51e0\u7387\u5c0f\u7684\u53ef\u4ee5\u5ffd\u7565\u4e0d\u8ba1\uff09\uff0c\u7531\u8282\u70b9\u673a\u5668\u7684IP\u5730\u5740\u901a\u8fc7\u54c8\u5e0c\u64cd\u4f5c\u5f97\u5230\u3002<\/p>\n \u8d44\u6e90ID\uff1bKID\uff08key identifiers\uff09\uff0c\u539f\u4e3a\u952eID\uff0c\u5176\u5b9e\u9645\u8868\u793a\u4e00\u4e2a\u8d44\u6e90\uff08\u56e0\u4e3aKey\u4e0e\u4e00\u4e2a\u8d44\u6e90value\u54c8\u5e0c\u7ed1\u5b9a\uff09\uff0c\u6545\u5728\u672c\u6587\u4e2d\u7edf\u79f0\u8d44\u6e90ID\uff08\u8fd9\u6837\u6bd4\u8f83\u76f4\u89c2\uff09\uff0cm\u4f4d\u7684\u4e00\u4e2a\u6570\u5b57\uff08m\u8981\u8db3\u591f\u5927\u4ee5\u4fdd\u8bc1\u4e0d\u540c\u8d44\u6e90\u7684KID\u76f8\u540c\u7684\u51e0\u7387\u5c0f\u7684\u53ef\u4ee5\u5ffd\u7565\u4e0d\u8ba1\uff09\uff0c\u7531Key\u901a\u8fc7\u54c8\u5e0c\u64cd\u4f5c\u5f97\u5230\u3002<\/p>\n \u5e38\u54c8\u5e0c\u51fd\u6570\uff1a\u8f83\u4e4b\u4e00\u822c\u54c8\u5e0c\u51fd\u6570\uff0c\u8282\u70b9\u7684\u52a0\u5165\u548c\u79bb\u5f00\u5bf9\u6574\u4e2a\u7cfb\u7edf\u5f71\u54cd\u6700\u5c0f\uff0c\u53e6\u5916\u8fd8\u6709\u4e00\u4e9b\u4f18\u52bf\u5728\u6b64\u4e0d\u8d58\u8ff0\u3002\u5728Chord\u4e2d\u4f7f\u7528SHA-1\u6765\u8fdb\u884c\u5e38\u54c8\u5e0c\u8ba1\u7b97\u3002<\/p>\n Chord\u73af\uff1aChord Ring\uff0cNID\u548cKID\u88ab\u5206\u914d\u5230\u4e00\u4e2a\u5927\u5c0f\u4e3a2^m\u7684\u73af\u4e0a\uff0c\u7528\u4e8e\u8d44\u6e90\u5206\u914d\uff08\u7ed9\u67d0\u4e00\u4e2a\u8282\u70b9\uff09\u548c\u8282\u70b9\u5206\u5e03\uff0c\u4ee5\u53ca\u8d44\u6e90\u5b9a\u4f4d\uff08\u6ce8\uff1a\u5728\u8fd9\u4e2a\u73af\u4e0a\u7684ID\u4e3a0--2^m-1\uff09\u3002\u9996\u5148\u6211\u4eec\u8bf4\u8d44\u6e90\u5206\u914d\uff0c\u8d44\u6e90\u88ab\u5206\u914d\u5230NID>=KID\u7684\u8282\u70b9\u4e0a\uff0c\u8fd9\u4e2a\u8282\u70b9\u6210\u4e3ak\u7684\u540e\u7ee7\u8282\u70b9\uff0c\u662f\u73af\u4e0a\u4ecek\u8d77\u987a\u65f6\u9488\u65b9\u5411\u7684\u7b2c\u4e00\u4e2a\u8282\u70b9\uff0c\u8bb0\u4e3asuccessor(k)\u3002\u800c\u8282\u70b9\u5206\u5e03\u5219\u987a\u65f6\u9488\u5c06\u8282\u70b9N\u7531\u5927\u5230\u5c0f\u653e\u5728\u8fd9\u4e2a\u73af\u4e0a\u3002\u4f8b\u5982\u4e0b\u8fb9\u8fd9\u5e45\u56fe\uff1a<\/p>\n \n \u8fd9\u662f\u4e00\u4e2am=6\u7684\u73af\uff0c\u5176\u4e2d\u670910\u4e2a\u8282\u70b9\uff0c5\u4e2a\u8d44\u6e90\uff0cK10\u7684\u540e\u7ee7\u8282\u70b9\u4e3aN14\uff0c\u4e5f\u5c31\u662f\u8bf4K10\u88ab\u5206\u914d\u7ed9\u4e86N14\u3002<\/p>\n 2.Chord\u8d44\u6e90\u5b9a\u4f4d\uff08Key Location\uff09<\/strong><\/p>\n \u8d44\u6e90\u5b9a\u4f4d\u662fChord\u534f\u8bae\u7684\u6838\u5fc3\u529f\u80fd\uff0c\u4e3a\u4e86\u4fbf\u4e8e\u7406\u89e3\uff0c\u6211\u4eec\u5148\u4ecb\u7ecd\u4e00\u4e2a\u7b80\u5355\u7684\u8d44\u6e90\u5b9a\u4f4d\u65b9\u6cd5\uff0c\u7136\u540e\u518d\u4ecb\u7ecd\u8fd9\u4e2a\u53ef\u4f38\u7f29\u7684\u8d44\u6e90\u5b9a\u4f4d\u65b9\u6cd5\u3002<\/p>\n \u7b80\u5355\u65b9\u6cd5\uff1a<\/strong><\/p>\n \u8003\u8651\u5982\u4e0b\u573a\u666f\uff1a\u8282\u70b9n\u5bfb\u627eKID\u4e3aid\u7684\u8d44\u6e90\uff0c\u6b64\u65f6\u8282\u70b9n\u9996\u5148\u95ee\u8be2\u662f\u5426\u5728\u4e0b\u4e00\u4e2a\u8282\u70b9\u4e0a\uff08find_successor\uff09\uff0c\u8fd9\u8981\u770b\u8d44\u6e90k\u7684KID\u662f\u5426\u5728\u8be5\u8282\u70b9NID\u548c\u4e0b\u4e00\u4e2a\u8282\u70b9\u7684NID\u4e4b\u95f4\uff0c\u82e5\u5728\u5219\u8bf4\u660e\u8d44\u6e90k\u88ab\u5206\u914d\u7ed9\u4e86\u4e0b\u4e00\u4e2a\u8282\u70b9\uff0c\u82e5\u4e0d\u5728\u5219\u5728\u4e0b\u4e00\u4e2a\u8282\u70b9\u4e0a\u53d1\u8d77\u540c\u6837\u7684\u67e5\u8be2\uff0c\u95ee\u8be2\u4e0b\u4e0b\u4e00\u4e2a\u70b9\u662f\u5426\u6709\u8be5\u8d44\u6e90\u3002\u5982\u6b64\u8fed\u4ee3\u4e0b\u53bb\uff0c\u7528\u4f2a\u4ee3\u7801\u5b9a\u4e49\u8fd9\u4e2a\u64cd\u4f5c\uff1a<\/p>\n n.find_successor(id) \u4f8b\u5982\u4e0b\u56fe\uff1a<\/p>\n \n \u8282\u70b9N8\u5bfb\u627eK54\u8fd9\u4e2a\u8d44\u6e90\uff0cN8.find_successor(K54)\u53d1\u73b0\u4e0b\u4e00\u4e2a\u8282\u70b9N14\u4e0d\u5408\u7b2654\u0454 (8; 14]\uff0c\u4e8e\u662fN14\u53d1\u8d77\u540c\u6837\u7684\u641c\u7d22\uff0c\u7136\u540e\u4e00\u8df3\u4e00\u8df3\u540e\u76f4\u5230\u8282\u70b9N56\u6ee1\u8db354\u0454 (51; 56]\uff0c\u4e8e\u662f\u5f97\u77e5\u8d44\u6e90K54\u5728N56\u8fd9\u4e2a\u8282\u70b9\u4e0a\u3002<\/p>\n \u5728\u4e00\u4e2a\u6709N\u4e2a\u8282\u70b9\u7684\u73af\u4e0a\uff0c\u8fd9\u6837\u7684\u67e5\u627e\u65b9\u6cd5\u663e\u7136\u5728\u6700\u574f\u7684\u65f6\u5019\u8981\u67e5\u627eN\u6b21\u624d\u80fd\u5f97\u5230\u6240\u9700\u8d44\u6e90\u7684\u4f4d\u7f6e\uff0c\u67e5\u627e\u6b21\u6570\u4e0e\u8282\u70b9\u4e2a\u6570\u6210\u7ebf\u6027\u5173\u7cfb\u3002\u663e\u7136\uff0c\u8fd9\u6837\u7684\u6548\u7387\u4e0d\u7ed9\u529b\uff0c\u6240\u4ee5Chord\u4f7f\u7528\u4e86\u53ef\u4f38\u7f29\u8d44\u6e90\u5b9a\u4f4d\u7684\u65b9\u5f0f\u6765\u63d0\u9ad8\u6548\u7387\u3002<\/p>\n \u53ef\u4f38\u7f29\u65b9\u6cd5\uff1a<\/strong><\/p>\n \u5728\u6bcf\u4e2a\u8282\u70b9N\u4e0a\u90fd\u7ef4\u62a4\u4e86\u6700\u591a\u6709m\u9879\uff08m\u4e3aID\u7684\u4f4d\u6570\uff09\u7684\u8def\u7531\u8868\uff08\u79f0\u4e3afinger table\uff09\uff0c\u7528\u6765\u5b9a\u4f4d\u8d44\u6e90\u3002\u8fd9\u4e2a\u8868\u7684\u7b2ci\u9879\u662f\u8be5\u8282\u70b9\u7684\u540e\u7ee7\u8282\u4f4d\u7f6e\uff0c\u81f3\u5c11\u5305\u542b\u52302^(i-1)\u540e\u7684\u4f4d\u7f6e\u3002\u8fd8\u662f\u5ef6\u7eed\u4e0a\u8fb9\u7684\u4f8b\u5b50\uff1a<\/p>\n \n \u8282\u70b9N8\u7684\u8def\u7531\u8868\u4e2d\uff0c\u5de6\u8fb9\u90a3\u4e00\u680f\u5305\u542b\u4e86N8+1\u5230N8+32\uff082^5-1\uff09\u7684\u4f4d\u7f6e\uff0c\u53f3\u8fb9\u90a3\u4e00\u680f\u6bcf\u4e2a\u4f4d\u7f6e\u5bf9\u5e94\u7684\u5b9e\u9645\u5b58\u5728\u7684\u8282\u70b9\u3002\u6bd4\u5982N8+1-N14\uff0c\u8868\u793a\u5728N8\u540e\u7684\u7b2c\u4e00\u4e2a\u4f4d\u7f6e\u4e0a\u7684\u8d44\u6e90\u7531N14\u6765\u8d1f\u8d23\u3002\u8fd9\u6837\u8bb0\u5f55\u6709\u4ee5\u4e0b\u4f18\u52bf\uff1a<\/p>\n \u6bcf\u4e2a\u8282\u70b9\u53ea\u5305\u542b\u5168\u7f51\u4e2d\u4e00\u5c0f\u90e8\u5206\u8282\u70b9\u7684\u4fe1\u606f\u3002<\/p>\n \u6bcf\u4e2a\u8282\u70b9\u5bf9\u4e8e\u4e34\u8fd1\u8282\u70b9\u8d1f\u8d23\u7684\u4f4d\u7f6e\u77e5\u9053\u7684\u66f4\u591a\uff0c\u6bd4\u5982N8\u8282\u70b9\u5bf9\u4e8eN14\u8d1f\u8d23\u7684\u4f4d\u7f6e\u77e5\u90533\u5904\uff0c\u800c\u5bf9N21\u8d1f\u8d23\u7684\u4f4d\u7f6e\u53ea\u77e5\u90531\u5904\u3002<\/p>\n \u8def\u7531\u8868\u901a\u5e38\u4e0d\u5305\u542b\u76f4\u63a5\u627e\u5230\u540e\u7ee7\u8282\u70b9\u7684\u4fe1\u606f\uff0c\u5f80\u5f80\u9700\u8981\u8be2\u95ee\u5176\u4ed6\u8282\u70b9\u6765\u5b8c\u6210\u3002<\/p>\n \u5f53\u5728\u67d0\u4e2a\u8282\u70b9\u4e0a\u67e5\u627e\u8d44\u6e90\u65f6\uff0c\u9996\u5148\u5224\u65ad\u5176\u540e\u7ee7\u8282\u70b9\u662f\u4e0d\u662f\u5c31\u6301\u6709\u8be5\u8d44\u6e90\uff0c\u82e5\u6ca1\u6709\u5219\u76f4\u63a5\u4ece\u8be5\u8282\u70b9\u7684\u8def\u7531\u8868\u4ece\u6700\u8fdc\u5904\u5f00\u59cb\u67e5\u627e\uff0c\u770b\u54ea\u4e00\u9879\u79bb\u6301\u6709\u8d44\u6e90\u7684\u8282\u70b9\u6700\u8fd1\uff08\u53d1\u73b0\u540e\u8df3\u8f6c\uff09\uff0c\u82e5\u6ca1\u6709\u5219\u8bf4\u660e\u672c\u8282\u70b9\u81ea\u8eab\u5c31\u6709\u8981\u5bfb\u627e\u7684\u8d44\u6e90\u3002\u5982\u6b64\u8fed\u4ee3\u4e0b\u53bb\u3002<\/p>\n \u4f8b\u5982\uff1a\u8282\u70b9N8\u5bfb\u627eK54\u8fd9\u4e2a\u8d44\u6e90<\/p>\n \n \u9996\u5148\uff0c\u5728N8\u4e0a\u67e5\u627e\u540e\u7ee7\u8282\u70b9\u4e3aN14\uff0c\u53d1\u73b0K54\u5e76\u4e0d\u7b26\u540854\u0454 (8; 14]\u7684\u8981\u6c42\uff0c\u90a3\u4e48\u76f4\u63a5\u5728N8\u7684\u8def\u7531\u8868\u4e0a\u67e5\u627e\u7b26\u5408\u8fd9\u4e2a\u8981\u6c42\u7684\u8868\u9879\uff08\u7531\u8fdc\u53ca\u8fd1\u67e5\u627e\uff09\uff0c\u6b64\u65f6N8\u7684\u8def\u7531\u8868\u4e3a\uff1a<\/p>\n \n \u6211\u4eec\u53d1\u73b0\u8def\u7531\u8868\u4e2d\u6700\u8fdc\u7684\u4e00\u9879N8+32--N42\u6ee1\u8db342\u0454 (8; 54]\uff0c\u5219\u8bf4\u660eN42\u8fd9\u4e2a\u70b9\u79bb\u6301\u6709K54\u8fd9\u4e2a\u8d44\u6e90\u7684\u8282\u70b9\u6700\u8fd1\uff08\u56e0\u4e3aN42\u5728\u8be5\u8def\u7531\u8868\u4e2d\u79bbN8\u8fd9\u4e2a\u8282\u70b9\u6700\u8fdc\uff09\uff0c\u90a3\u4e48\u6b64\u65f6\u8df3\u5230N42\u8fd9\u4e2a\u8282\u70b9\u4e0a\u7ee7\u7eed\u67e5\u627e\u3002N42\u7684\u540e\u7ee7\u8282\u70b9\u4e3aN48\uff0c\u4e0d\u7b26\u540854\u0454 (42; 48]\u7684\u8981\u6c42\uff0c\u8bf4\u660eN48\u4e0d\u6301\u6709\u8d44\u6e9054\uff0c\u6b64\u65f6\uff0c\u5f00\u59cb\u5728N42\u7684\u8def\u7531\u8868\u4e0a\u67e5\u627e\uff1a<\/p>\n N42\u8282\u70b9\u7684\u8def\u7531\u8868\u4e3a\uff1a<\/p>\n \n \u6211\u4eec\u7531\u8fdc\u53ca\u8fd1\u5f00\u59cb\u67e5\u627e\uff0c\u53d1\u73b0N42+8--N51\u6ee1\u8db351\u0454 (42; 54]\uff0c\u5219\u8bf4\u660eN51\u8fd9\u4e2a\u70b9\u79bb\u6301\u6709K54\u8fd9\u4e2a\u8d44\u6e90\u7684\u8282\u70b9\u6700\u8fd1\uff0c\u90a3\u4e48\u6b64\u65f6\u8df3\u5230N51\u8fd9\u4e2a\u8282\u70b9\u4e0a\u7ee7\u7eed\u67e5\u627e\u3002N51\u8282\u70b9\u7684\u540e\u7ee7\u8282\u70b9\u4e3aN56\uff0c\u7b26\u540854\u0454 (51; 56]\uff0c\u6b64\u65f6\u5b9a\u4f4d\u5b8c\u6210\uff0cN56\u6301\u6709\u8d44\u6e90\u8282\u70b9K54\u3002<\/p>\n \u7528\u4f2a\u4ee3\u7801\u8868\u793a\uff1a<\/p>\n \/\/ \u67e5\u8be2\u8282\u70b9n\u540e\u7ee7\u8282\u70b9\u3002 \u7ecf\u8bc1\u660e\uff0c\u6700\u591a\u7ecf\u8fc7O(log N)\u6b21\u67e5\u627e\u5c31\u80fd\u627e\u5230\u4e00\u4e2a\u8d44\u6e90\u3002<\/p>\n 3.Chord\u7684\u8282\u70b9\u52a0\u5165<\/strong><\/p>\n Chord\u901a\u8fc7\u5728\u6bcf\u4e2a\u8282\u70b9\u7684\u540e\u53f0\u5468\u671f\u6027\u7684\u8fdb\u884cstabilization\u8be2\u95ee\u540e\u7ee7\u8282\u70b9\u7684\u524d\u5e8f\u8282\u70b9\u662f\u4e0d\u662f\u81ea\u5df1\u6765\u66f4\u65b0\u540e\u7ee7\u8282\u70b9\u4ee5\u53ca\u8def\u7531\u8868\u4e2d\u7684\u9879\u3002<\/p>\n \u6709\u4e09\u4e2a\u64cd\u4f5c\uff1a Stabilize(): n\u67e5\u8be2\u5176\u540e\u7ee7\u8282\u70b9\u7684\u524d\u5e8f\u8282\u70b9P\u6765\u51b3\u5b9aP\u662f\u5426\u5e94\u8be5\u662fn\u7684\u540e\u7eed\u8282\u70b9\uff0c\u4e5f\u5c31\u662f\u8bf4\u5f53p\u4e0d\u662fn\u672c\u8eab\u65f6\uff0c\u8bf4\u660ep\u662f\u65b0\u52a0\u5165\u7684\uff0c\u6b64\u65f6\u5c06n\u7684\u540e\u7ee7\u8282\u70b9\u8bbe\u7f6e\u4e3ap\u3002<\/p>\n Notify(n0): n0\u901a\u77e5n\u5b83\u7684\u5b58\u5728\uff0c\u82e5\u6b64\u65f6n\u6ca1\u6709\u524d\u5e8f\u8282\u70b9\u6216\uff0cn0\u6bd4n\u73b0\u6709\u7684\u524d\u5e8f\u8282\u70b9\u66f4\u52a0\u9760\u8fd1n\uff0c\u5219n\u5c06\u5176\u8bbe\u7f6e\u4e3a\u524d\u5e8f\u8282\u70b9\u3002<\/p>\n Fix_fingers(): \u4fee\u6539\u8def\u7531\u8868\u3002<\/p>\n \u5177\u4f53\u7684\uff0c\u4f8b\u5982\uff1a<\/p>\n \u8fd9\u662f\u539f\u5148\u7684\u7ed3\u6784\uff1a<\/p>\n \n \u73b0\u5728N26\u8282\u70b9\u8981\u52a0\u5165\u7cfb\u7edf\uff0c\u9996\u5148\u5b83\u6307\u5411\u5176\u540e\u7ee7N32\uff0c\u7136\u540e\u901a\u77e5N32\uff0cN32\u63a5\u5230\u901a\u77e5\u540e\u5c06N26\u6807\u8bb0\u4e3a\u5b83\u7684\u524d\u5e8f\u8282\u70b9\uff08predecessor\uff09\u3002\u5982\u4e0b\u56fe\uff1a<\/p>\n \n \u7136\u540eN26\u4fee\u6539\u8def\u7531\u8868\uff0c\u5982\u4e0b\u56fe\uff1a<\/p>\n \n \u4e0b\u4e00\u6b21N21\u8fd0\u884cstabilize()\u8be2\u95ee\u5176\u540e\u7ee7\u8282\u70b9N32\u7684\u524d\u5e8f\u8282\u70b9\u662f\u4e0d\u662f\u8fd8\u662f\u81ea\u5df1\uff0c\u6b64\u65f6\u53d1\u73b0N32\u7684\u524d\u5e8f\u8282\u70b9\u5df2\u7ecf\u662fN26\uff1a<\/p>\n \n \u4e8e\u662fN21\u5c31\u5c06\u540e\u7ee7\u8282\u70b9\u4fee\u6539\u4e3aN26\uff0c\u5e76\u901a\u77e5N26\u81ea\u5df1\u5df2\u7ecf\u5c06\u5176\u8bbe\u7f6e\u4e3a\u540e\u7ee7\u8282\u70b9\uff0cN26\u63a5\u5230\u901a\u77e5\u540e\u5c06N21\u8bbe\u7f6e\u4e3a\u81ea\u5df1\u7684\u524d\u5e8f\u8282\u70b9\u3002<\/p>\n \u8fd9\u4e2a\u52a0\u5165\u64cd\u4f5c\u4f1a\u5e26\u6765\u4e24\u65b9\u9762\u7684\u5f71\u54cd\uff1a<\/p>\n 1)\u6b63\u786e\u6027\u65b9\u9762\uff1a\u5f53\u4e00\u4e2a\u8282\u70b9\u52a0\u5165\u7cfb\u7edf\uff0c\u800c\u4e00\u4e2a\u67e5\u627e\u53d1\u751f\u5728stabilization\u7ed3\u675f\u524d\uff0c\u90a3\u4e48\u6b64\u65f6\u7cfb\u7edf\u4f1a\u6709\u4e09\u4e2a\u72b6\u6001\uff1a<\/p>\n A.\u6240\u6709\u540e\u7ee7\u6307\u9488\u548c\u8def\u7531\u8868\u9879\u90fd\u6b63\u786e\u65f6\uff1a\u5bf9\u6b63\u786e\u6027\u6ca1\u6709\u5f71\u54cd\u3002<\/p>\n B.\u540e\u7ee7\u6307\u9488\u6b63\u786e\u4f46\u8868\u9879\u4e0d\u6b63\u786e\uff1a\u67e5\u627e\u7ed3\u679c\u6b63\u786e\uff0c\u4f46\u901f\u5ea6\u7a0d\u6162\uff08\u5728\u76ee\u6807\u8282\u70b9\u548c\u76ee\u6807\u8282\u70b9\u7684\u540e\u7ee7\u5904\u52a0\u5165\u975e\u5e38\u591a\u4e2a\u8282\u70b9\u65f6\uff09\u3002\u5982\u4e0b\u56fe\uff1a<\/p>\n \n C.\u540e\u7ee7\u6307\u9488\u548c\u8def\u7531\u8868\u9879\u90fd\u4e0d\u6b63\u786e\uff1a\u6b64\u65f6\u67e5\u627e\u5931\u8d25\uff0cChord\u4e0a\u5c42\u7684\u8f6f\u4ef6\u4f1a\u53d1\u73b0\u6570\u636e\u67e5\u627e\u5931\u8d25\uff0c\u5728\u4e00\u6bb5\u65f6\u95f4\u540e\u4f1a\u8fdb\u884c\u91cd\u8bd5\u3002<\/p>\n \u603b\u7ed3\u4e00\u4e0b\uff1a\u8282\u70b9\u52a0\u5165\u5bf9\u6570\u636e\u67e5\u627e\u6ca1\u6709\u5f71\u54cd\u3002<\/p>\n 2)\u6548\u7387\u65b9\u9762\uff1a\u5f53stabilization\u5b8c\u6210\u65f6\uff0c\u5bf9\u67e5\u627e\u6548\u7387\u7684\u5f71\u54cd\u4e0d\u4f1a\u8d85\u8fc7O(log N) \u7684\u65f6\u95f4\u3002\u5f53stabilization\u672a\u5b8c\u6210\u65f6\uff0c\u5728\u76ee\u6807\u8282\u70b9\u548c\u76ee\u6807\u8282\u70b9\u7684\u540e\u7ee7\u5904\u52a0\u5165\u975e\u5e38\u591a\u4e2a\u8282\u70b9\u65f6\u624d\u4f1a\u6709\u6027\u80fd\u5f71\u54cd\u3002\u53ef\u4ee5\u8bc1\u660e\uff0c\u53ea\u8981\u8def\u7531\u8868\u8c03\u6574\u901f\u5ea6\u5feb\u4e8e\u7f51\u7edc\u8282\u70b9\u6570\u91cf\u52a0\u500d\u7684\u901f\u5ea6\uff0c\u6027\u80fd\u5c31\u4e0d\u53d7\u5f71\u54cd\u3002<\/p>\n 4.Chord\u8282\u70b9\u5931\u8d25\u7684\u5904\u7406<\/strong><\/p>\n \u6211\u4eec\u53ef\u4ee5\u770b\u51fa\uff0cChord\u4f9d\u8d56\u540e\u7ee7\u6307\u9488\u7684\u6b63\u786e\u6027\u4ee5\u4fdd\u8bc1\u6574\u4e2a\u7f51\u7edc\u7684\u6b63\u786e\u6027\u3002\u4f46\u5982\u56fe\uff0c\u82e5N14, N21, N32\u540c\u65f6\u5931\u6548\uff0c\u90a3\u4e48N8\u662f\u4e0d\u4f1a\u77e5\u9053N38\u662f\u5b83\u65b0\u7684\u540e\u7ee7\u8282\u70b9\u3002\u4e3a\u4e86\u9632\u6b62\u8fd9\u6837\u7684\u60c5\u51b5\uff0c\u6bcf\u4e2a\u8282\u70b9\u90fd\u5305\u542b\u4e00\u4e2a\u5927\u5c0f\u4e3ar\u7684\u540e\u7ee7\u8282\u70b9\u5217\u8868\uff0c\u4e00\u4e2a\u540e\u7eed\u8282\u70b9\u5931\u6548\u4e86\u5c31\u4f9d\u6b21\u5c1d\u8bd5\u5217\u8868\u4e2d\u7684\u5176\u4ed6\u540e\u7ee7\u8282\u70b9\u3002\u53ef\u4ee5\u8bc1\u660e\uff0c\u5728\u5931\u6548\u51e0\u7387\u4e3a1\/2\u7684\u7f51\u7edc\u4e2d\uff0c\u5bfb\u627e\u540e\u7ee7\u7684\u65f6\u95f4\u4e3aO(log N) \u3002<\/p>\n 5.Chord\u7684\u7279\u5f81\u548c\u5e94\u7528<\/strong><\/p>\n \u7279\u5f81\uff1a\u53bb\u4e2d\u5fc3\u5316\uff0c\u9ad8\u53ef\u7528\u5ea6\uff0c\u9ad8\u4f38\u7f29\u6027\uff0c\u8d1f\u8f7d\u5e73\u8861\uff0c\u547d\u540d\u7075\u6d3b\u3002<\/p>\n \u5e94\u7528\uff1a\u5168\u7403\u6587\u4ef6\u7cfb\u7edf\u3001\u547d\u540d\u670d\u52a1\u3001\u6570\u636e\u5e93\u8bf7\u6c42\u5904\u7406\u3001\u4e92\u8054\u7f51\u7ea7\u522b\u7684\u6570\u636e\u7ed3\u6784\u3001\u901a\u4fe1\u670d\u52a1\u3001\u4e8b\u4ef6\u901a\u77e5\u3001\u6587\u4ef6\u5171\u4eab\u3002\u70b9\u51fb\u6253\u5f00\u94fe\u63a5<\/p>\n","protected":false},"excerpt":{"rendered":"Chord\u7b97\u6cd5_diff\u7b97\u6cd5\u65f6\u95f4\u590d\u6742\u5ea6http:\/\/blog.csdn.net\/wangxiaoqin00007\/article\/details\/P2P\u7684\u4e00\u4e2a\u5e38\u89c1\u95ee\u9898\u662f\u5982\u4f55\u9ad8\u6548\u7684\u5b9a\u4f4d\u8282...","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[],"_links":{"self":[{"href":"https:\/\/mushiming.com\/wp-json\/wp\/v2\/posts\/5364"}],"collection":[{"href":"https:\/\/mushiming.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mushiming.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mushiming.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mushiming.com\/wp-json\/wp\/v2\/comments?post=5364"}],"version-history":[{"count":0,"href":"https:\/\/mushiming.com\/wp-json\/wp\/v2\/posts\/5364\/revisions"}],"wp:attachment":[{"href":"https:\/\/mushiming.com\/wp-json\/wp\/v2\/media?parent=5364"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mushiming.com\/wp-json\/wp\/v2\/categories?post=5364"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mushiming.com\/wp-json\/wp\/v2\/tags?post=5364"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
if (id \u0454 (n; successor])
return successor;
else
\/\/ \u5c06\u67e5\u8be2\u6cbf\u7740\u73af\u8fdb\u884c\u4e0b\u53bb
return successor.find_successor(id);<\/p>\n
n.find_successor(id)
if (id \u0454 (n; successor])
return successor;
else n0 = closest_preceding_node(id);
return n0.find successor(id);
\/\/ search the local table for the highest
\/\/ predecessor of id
n.closest_preceding_node(id)
for i = m downto 1
if (finger[i] \u0454 (n; id))
return finger[i];
return n;<\/p>\n
join(n0) \uff1an\u52a0\u5165\u4e00\u4e2aChord\u73af\uff0c\u5df2\u77e5\u5176\u4e2d\u6709\u4e00\u4e2a\u8282\u70b9n0.<\/p>\n