// By Haw-ren Fang, TA of cmsc420-0401, Spring 2002

import java.io.*;
import java.lang.*;
import java.util.Hashtable;

// Usage: HashTableDriver2 [input file] [size1] [size2] [size3] ...
// The driver will read in a file that contains patch identifiers (or
// simply, patches).  A patch identifier is a string satisfying the
// regular expression [a-z][a-z]{0,1}*. Each patch is terminated by a new
// line. An example file is:
// pq011001 2.3 2.4 2.5 3.3 3.4 3.5 4.3 4.4 4.5 6.6 6.4 6.5
// pr101101 2.3 2.4 2.5 3.3 3.4 3.5 4.3 4.4 4.5 6.6 6.4 6.5
// The items, (key, value) pairs, will be stored in the hashtable
// The output will report probing counts (cost) of linear and double
// hashing. You can get 10/10 points if the result shows your double
// hashing is more efficient than linear probing.

public class HashTableDriver2 {
	private static void printUsage() {
		System.out.println("Usage: HashTableDriver2 [input file] [size1] [size2] [size3] ...");
		System.exit(1);
	}

	private static void putError(String key) {
		System.err.println("Error occurs while running HashTable.put() with key=" + key);
		System.err.println("Either your HashTable does not guarantee successful insert when there is an empty address available,");
		System.err.println("Or your HashTable does not reject duplicate keys.");
		System.err.println("You get 0/10 points." );
		System.exit(1);
	}

	public static void main(String args[]) throws Exception {
		if (args.length <= 1)
			printUsage();

		String key, value;
		System.out.println("Double hashing test:");
		try {
			for (int i=1; i<args.length; i++) {
				int size = Integer.parseInt(args[i]);
				int putCount = 0;
				if (size <= 0)
					continue;
				Hashtable table0 = new Hashtable(); // JDK version
				HashTable table1 = new HashTable(size) {
					public int probeHashValue(String k) {
						return 1; // linear probing
					}
				};
				// double hashing
				HashTable table2 = new HashTable(size);

				size = table1.getSize();
				if (size != table2.getSize() ) {
					System.err.println("HashTable.getSize() Error.");
					System.err.println("You get 0/10 points." );
					System.exit(1);
				}
				FileInputStream fileInput = new FileInputStream(args[0]);
				for (int j=0; j<size; j++) {
					int c;
					StringBuffer key0 = new StringBuffer();
					StringBuffer value0 = new StringBuffer();
					while (true) {
						c = fileInput.read();
						if (c==-1) // end of file
							break;
						if ((char)c==' ')
							break;
						key0.append((char)c);
					}
					if (c==-1)
						break;
					
					while (true) {
						c = fileInput.read();
						if (c==-1)
							break;
						if ((char)c=='\n')
							break;
						value0.append((char)c);
					}
					if (c==-1)
						break;
					key = key0.toString();
					value = value0.toString();
					// System.out.println("key=" + key + ", value=" + value);
					if (!table0.containsKey(key)) {
						putCount ++;
						table0.put(key, value);
						if (!table1.put(key, value))
							putError(key);
						if (!table2.put(key, value))
							putError(key);
					}
					else {
						if (table1.put(key, value))
							putError(key);
						if (table2.put(key, value))
							putError(key);
					}
				}
				System.out.println("Table size: " + size +
				", Items inserted: " + putCount);
				System.out.println("Loading factor: " +
				(double)putCount/(double)size);
				System.out.println("Linear probing count: " + table1.probeCount);
				System.out.println("Double hashing count: " + table2.probeCount);
				fileInput.close();
			}
		}
		catch(FileNotFoundException e1) {
			printUsage();
		}
		catch(Exception e2) {
			e2.printStackTrace();
			System.err.println("You get 0/10 points.");
			System.exit(1);
		}
	}
}