Utils.java

package com.mopub.common.util;

import com.mopub.common.VisibleForTesting;

import java.security.MessageDigest;
import java.util.Locale;
import java.util.concurrent.atomic.AtomicLong;

public class Utils {
    private static final AtomicLong sNextGeneratedId = new AtomicLong(1);

    public static String sha1(String string) {
        StringBuilder stringBuilder = new StringBuilder();

        try {
            MessageDigest digest = MessageDigest.getInstance("SHA-1");
            byte[] bytes = string.getBytes("UTF-8");
            digest.update(bytes, 0, bytes.length);
            bytes = digest.digest();

            for (final byte b : bytes) {
                stringBuilder.append(String.format("%02X", b));
            }

            return stringBuilder.toString().toLowerCase(Locale.US);
        } catch (Exception e) {
            return "";
        }
    }

    /**
     * Adaptation of View.generateViewId() from API 17.
     * There is only a guarantee of ID uniqueness within a given session. Please do not store these
     * values between sessions.
     */
    public static long generateUniqueId() {
        for (;;) {
            final long result = sNextGeneratedId.get();
            long newValue = result + 1;
            if (newValue > Long.MAX_VALUE - 1) {
                newValue = 1;
            }
            if (sNextGeneratedId.compareAndSet(result, newValue)) {
                return result;
            }
        }
    }

    public static boolean bitMaskContainsFlag(final int bitMask, final int flag) {
        return (bitMask & flag) != 0;
    }
}