/** start recording of history */
public void beginRecording() {
history_ = new SparseMatrix<Integer>();
time_ = 1;
history_.set(getTableSize(), 1, 0);
for (int i = 0; i < table_.size(); ++i) {
SList<T> bucket = table_.at(i);
if (!bucket.empty()) history_.set(i, time_, bucket.size());
}
}
@Override
public String toString() {
String s =
"SimpleHashTable [m="
+ getTableSize()
+ ", n="
+ getNumEntries()
+ ", n/m="
+ getLoadFactor()
+ ", counted "
+ nCollisions_
+ " collisions]\n";
for (int i = 0; i < table_.size(); ++i) {
SList<T> bucket = table_.at(i);
s += i + ": ";
if (!bucket.empty()) s += bucket.toString();
s += "\n";
}
return s;
}
/**
* insert {@code key}
*
* @return {@code true} if this caused a collision
*/
boolean insert(T key) {
long h = hash_.hash(key);
int idx = (int) (h % table_.size());
SList<T> bucket = table_.at(idx);
if (bucket.empty()) {
++n_;
bucket.push_front(key);
recordInsert(idx);
if (verbose) System.err.println("SimpleHashTable: insert " + key + " @ " + idx);
return false;
} else if (onCollision_ == null) { // separate chaining
++n_;
bucket.push_front(key);
recordInsert(idx);
++nCollisions_;
if (verbose)
System.err.println(
"SimpleHashTable: insert "
+ key
+ " @ "
+ idx
+ " (bucket size="
+ bucket.size()
+ ")");
return true;
} else {
for (int j = 1; j < table_.size(); ++j) {
if (verbose) System.err.println("SimpleHashTable: insert " + key + " with " + onCollision_);
h = onCollision_.newHash(this, key, h, j);
if (verbose) System.err.print("SimpleHashTable: " + idx + " occupied => ");
idx = (int) (h % table_.size());
if (verbose) System.err.println(idx);
++nCollisions_;
if ((bucket = table_.at(idx)).empty()) {
++n_;
bucket.push_front(key);
recordInsert(idx);
return true;
}
}
// give up after N tries !
throw new RuntimeException("collision handling failed!");
}
}