private CharKeyOpenHashMap(
CharHashFunction keyhash,
int capacity,
int growthPolicy,
double growthFactor,
int growthChunk,
double loadFactor) {
if (keyhash == null) Exceptions.nullArgument("hash function");
if (capacity < 0) Exceptions.negativeArgument("capacity", String.valueOf(capacity));
if (growthFactor <= 0.0)
Exceptions.negativeOrZeroArgument("growthFactor", String.valueOf(growthFactor));
if (growthChunk <= 0)
Exceptions.negativeOrZeroArgument("growthChunk", String.valueOf(growthChunk));
if (loadFactor <= 0.0)
Exceptions.negativeOrZeroArgument("loadFactor", String.valueOf(loadFactor));
this.keyhash = keyhash;
capacity = Primes.nextPrime(capacity);
keys = new char[capacity];
values = (Object[]) new Object[capacity];
this.states = new byte[capacity];
size = 0;
expandAt = (int) Math.round(loadFactor * capacity);
this.used = 0;
this.growthPolicy = growthPolicy;
this.growthFactor = growthFactor;
this.growthChunk = growthChunk;
this.loadFactor = loadFactor;
}
private void ensureCapacity(int elements) {
if (elements >= expandAt) {
int newcapacity;
if (growthPolicy == GROWTH_POLICY_RELATIVE)
newcapacity = (int) (keys.length * (1.0 + growthFactor));
else newcapacity = keys.length + growthChunk;
if (newcapacity * loadFactor < elements)
newcapacity = (int) Math.round(((double) elements / loadFactor));
newcapacity = Primes.nextPrime(newcapacity);
expandAt = (int) Math.round(loadFactor * newcapacity);
char[] newkeys = new char[newcapacity];
Object[] newvalues = (Object[]) new Object[newcapacity];
byte[] newstates = new byte[newcapacity];
used = 0;
// re-hash
for (int i = 0; i < keys.length; i++) {
if (states[i] == OCCUPIED) {
used++;
char k = keys[i];
Object v = values[i];
// first hash
int h = Math.abs(keyhash.hash(k));
int n = h % newcapacity;
if (newstates[n] == OCCUPIED) {
// second hash
int c = 1 + (h % (newcapacity - 2));
for (; ; ) {
n -= c;
if (n < 0) n += newcapacity;
if (newstates[n] == EMPTY) break;
}
}
newstates[n] = OCCUPIED;
newvalues[n] = v;
newkeys[n] = k;
}
}
keys = newkeys;
values = newvalues;
states = newstates;
}
}