}
if (k == null) {
replaceStaleEntry(key, value, i);
return;
}
}
tab = new Entry(key, value);
int sz = ++size;
if (!cleanSomeSlots(i, sz) && sz >= threshold)
rehash();
}
private void remove(Key key) {
Entry[] tab = table;
int len = tab.length;
int i = key.hashCode & (len-1);
for (Entry e = tab;
e != null;
e = tab[i = nextIndex(i, len)]) {
if (e.get() == key) {
e.clear();
expungeStaleEntry(i);
return;
}
}
}
private void replaceStaleEntry(Key key, Object value,
int staleSlot) {
Entry[] tab = table;
int len = tab.length;
Entry e;
int slotToExpunge = staleSlot;
for (int i = prevIndex(staleSlot, len);
(e = tab) != null;
i = prevIndex(i, len))
if (e.get() == null)
slotToExpunge = i;
for (int i = nextIndex(staleSlot, len);
(e = tab) != null;
i = nextIndex(i, len)) {
Key k = e.get();
if (k == key) {
e.value = value;
tab = tab[staleSlot];
tab[staleSlot] = e;
// Start expunge at preceding stale entry if it exists
if (slotToExpunge == staleSlot)
slotToExpunge = i;
cleanSomeSlots(expungeStaleEntry(slotToExpunge), len);
return;
}
if (k == null && slotToExpunge == staleSlot)
slotToExpunge = i;
}
// If key not found, put new entry in stale slot
tab[staleSlot].value = null;
tab[staleSlot] = new Entry(key, value);
// If there are any other stale entries in run, expunge them
if (slotToExpunge != staleSlot)
cleanSomeSlots(expungeStaleEntry(slotToExpunge), len);
}
/**擦除staleSlot的Entry。
*调整所有不在哈希映射位置的value的位置，让它尽量在哈希映射的位置
*/
private int expungeStaleEntry(int staleSlot) {
Entry[] tab = table;
int len = tab.length;
tab[staleSlot].value = null;
tab[staleSlot] = null;
size--;
// Rehash until we encounter null
Entry e;
int i;
for (i = nextIndex(staleSlot, len);
(e = tab) != null;
i = nextIndex(i, len)) {
Key k = e.get();
if (k == null) {
e.value = null;
tab = null;
size--;
} else {
int h = k.hashCode & (len - 1);
if (h != i) {
tab = null;
// Unlike Knuth 6.4 Algorithm R, we must scan until
// null because multiple entries could have been stale.
while (tab[h] != null)