MatchingMagicMimeEntry.java

/*
 * Copyright 2007-2009 Medsea Business Solutions S.L.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package eu.medsea.mimeutil.detector;

import java.util.Iterator;

import eu.medsea.mimeutil.MimeType;


class MatchingMagicMimeEntry
{
	public MatchingMagicMimeEntry(MagicMimeEntry magicMimeEntry) // , boolean exactMatch)
	{
		this.magicMimeEntry = magicMimeEntry;
	}

	private MagicMimeEntry magicMimeEntry;
	private double specificity = -1; // can only be positive when initialised - at least with our current formula ;-)

	public MagicMimeEntry getMagicMimeEntry() {
		return magicMimeEntry;
	}

	private int getLevel() {
		int l = 0;
		MagicMimeEntry parent = magicMimeEntry.getParent();
		while (parent != null) {
			++l;
			parent = parent.getParent();
		}
		return l;
	}

	private int getRecursiveSubEntryCount()
	{
		return getRecursiveSubEntryCount(magicMimeEntry, 0);
	}

	public int getRecursiveSubEntryCount(MagicMimeEntry entry, int subLevel)
	{
		++subLevel;
		int result = 0;
		for (Iterator it = entry.getSubEntries().iterator(); it.hasNext();) {
			MagicMimeEntry subEntry = (MagicMimeEntry) it.next();
			result += subLevel * (1 + getRecursiveSubEntryCount(subEntry, subLevel));
		}
		return result;
	}

	public double getSpecificity() {
		if (specificity < 0) {
			// The higher the level, the more specific it probably is.
			// The more children below the current match, the less specific it is.
			// TODO This formula needs to be changed/optimized.
			specificity = (double)(getLevel() + 1) / (getRecursiveSubEntryCount() + 1);
		}

		return specificity;
	}

	public MimeType getMimeType()
	{
		return new MimeType(magicMimeEntry.getMimeType());
	}

	public String toString() {
		return this.getClass().getName() + '[' + getMimeType() + ',' + getSpecificity() + ']';
	}
}