Add threading to VanityGen

src/main/java/org/qora/VanityGen.java

@@ -4,6 +4,8 @@ import java.io.IOException;
 import java.security.SecureRandom;
 import java.security.Security;
 import java.util.Random;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 
 import org.bouncycastle.jce.provider.BouncyCastleProvider;
 import org.bouncycastle.jsse.provider.BouncyCastleJsseProvider;
@@ -16,37 +18,87 @@ import com.google.common.primitives.Bytes;
 
 public class VanityGen {
 
+	// From utils.Base58:
+	private static final String ALPHABET_STR = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
+
+	private static String prefix = null;
+
+	private static void usage() {
+		System.err.println("Usage: Vanitygen [-t threads] <leading-chars>");
+		System.err.println("Example: VanityGen Qcat");
+		System.exit(1);
+	}
+
+	private static class Generator implements Runnable {
+		public void run() {
+			Random random = new SecureRandom();
+			byte[] entropy = new byte[16];
+
+			while (true) {
+				// Generate entropy internally
+				random.nextBytes(entropy);
+
+				// Use SHA256 to generate more bits
+				byte[] hash = Crypto.digest(entropy);
+
+				// Append first 4 bits from hash to end. (Actually 8 bits but we only use 4).
+				byte checksum = (byte) (hash[0] & 0xf0);
+				byte[] entropy132 = Bytes.concat(entropy, new byte[] { checksum });
+
+				String mnemonic = BIP39.encode(entropy132, "en");
+
+				PrivateKeyAccount account = new PrivateKeyAccount(null, hash);
+
+				if (!account.getAddress().startsWith(prefix))
+					continue;
+
+				System.out.println(String.format("Address: %s, public key: %s, private key: %s, mnemonic: %s",
+						account.getAddress(), Base58.encode(account.getPublicKey()), Base58.encode(hash), mnemonic));
+				System.out.flush();
+			}
+		}
+	}
+
 	public static void main(String argv[]) throws IOException {
-		if (argv.length != 1) {
+		if (argv.length == 0)
-			System.err.println("Usage: Vanitygen <leading-chars>");
+			usage();
-			System.err.println("Example: VanityGen Qcat");
+
-			return;
+		int threadCount = 1;
+
+		int argIndex = 0;
+		while (argIndex < argv.length) {
+			String arg = argv[argIndex++];
+
+			if (arg.equals("-t")) {
+				if (argIndex >= argv.length)
+					usage();
+
+				try {
+					threadCount = Integer.parseInt(argv[argIndex++]);
+				} catch (NumberFormatException e) {
+					usage();
+				}
+
+				continue;
+			}
+
+			if (prefix != null)
+				usage();
+
+			prefix = arg;
+			if (!prefix.matches("[" + ALPHABET_STR + "]+")) {
+				System.err.println("Only the following characters are allowed:\n" + ALPHABET_STR);
+				System.exit(1);
+			}
 		}
 
 		Security.insertProviderAt(new BouncyCastleProvider(), 0);
 		Security.insertProviderAt(new BouncyCastleJsseProvider(), 1);
 
-		Random random = new SecureRandom();
+		ExecutorService executor = Executors.newFixedThreadPool(threadCount);
-		byte[] entropy = new byte[16];
 
-		while (true) {
+		for (int ti = 0; ti < threadCount; ++ti)
-			// Generate entropy internally
+			executor.execute(new Generator());
-			random.nextBytes(entropy);
-
-			// Use SHA256 to generate more bits
-			byte[] hash = Crypto.digest(entropy);
-
-			// Append first 4 bits from hash to end. (Actually 8 bits but we only use 4).
-			byte checksum = (byte) (hash[0] & 0xf0);
-			byte[] entropy132 = Bytes.concat(entropy, new byte[] { checksum });
-
-			String mnemonic = BIP39.encode(entropy132, "en");
-
-			PrivateKeyAccount account = new PrivateKeyAccount(null, hash);
-
-			if (account.getAddress().startsWith(argv[0]))
-				System.out.println(String.format("Address: %s, public key: %s, private key: %s, mnemonic: %s", account.getAddress(), Base58.encode(account.getPublicKey()), Base58.encode(hash), mnemonic));
-		}
 	}
 
 }