我正在通過哈希映射的實現,並在代碼中找到了計算哈希碼的代碼。你能解釋一下h的價值是如何在下面計算的,以及它爲什麼以這種特定的方式完成的?哈希映射中的哈希碼約束
final int hash(Object k) {
int h = hashSeed;
if (0 != h && k instanceof String) {
return sun.misc.Hashing.stringHash32((String) k);
}
h ^= k.hashCode();
// This function ensures that hashCodes that differ only by
// constant multiples at each bit position have a bounded
// number of collisions (approximately 8 at default load factor).
h ^= (h >>> 20)^(h >>> 12);
return h^(h >>> 7)^(h >>> 4);
}