/**
* Puts the digram into collection, it overrides the old entry.
*
* @param digramFrequencyEntry The digram entry.
*/
public void put(DigramFrequencyEntry digramFrequencyEntry) {
this.digramsToEntries.put(digramFrequencyEntry.getDigram(), digramFrequencyEntry);
Integer freq = digramFrequencyEntry.getFrequency();
ArrayList<DigramFrequencyEntry> bucket = this.bucketsToEntries.get(freq);
if (null == bucket) {
bucket = new ArrayList<DigramFrequencyEntry>();
this.bucketsToEntries.put(freq, bucket);
}
bucket.add(digramFrequencyEntry);
}
/**
* Increments a frequency counter for a digram.
*
* @param entry the entry.
* @param increment the increment value.
*/
public void incrementFrequency(DigramFrequencyEntry entry, int increment) {
// findout the old bucket and remove this entry
ArrayList<DigramFrequencyEntry> oldBucket = this.bucketsToEntries.get(entry.getFrequency());
oldBucket.remove(entry);
if (oldBucket.isEmpty()) {
this.bucketsToEntries.remove(entry.getFrequency());
}
// get the increment added
int newFreq = entry.getFrequency() + increment;
entry.setFrequency(newFreq);
// put into the new bucket
ArrayList<DigramFrequencyEntry> bucket = this.bucketsToEntries.get(newFreq);
if (null == bucket) {
bucket = new ArrayList<DigramFrequencyEntry>();
this.bucketsToEntries.put(newFreq, bucket);
}
bucket.add(entry);
}
/**
* Removes the digram frequency entry from the collection.
*
* @param digramStr the digram string.
*/
public void remove(String digramStr) {
// get the entry
DigramFrequencyEntry entry = this.digramsToEntries.get(digramStr);
if (null == entry) {
return;
} else {
// get its frequency and the corresponding bucket
int freq = entry.getFrequency();
ArrayList<DigramFrequencyEntry> bucket = this.bucketsToEntries.get(freq);
if (!bucket.remove(entry)) {
throw (new RuntimeException("There was an error!"));
}
// check if the bucket left empty after deletion
if (bucket.isEmpty()) {
this.bucketsToEntries.remove(freq);
}
// now clean-up the second map
this.digramsToEntries.remove(digramStr);
}
// and drop the entry itself
entry = null;
}