Example usage for io.netty.util.internal ConstantTimeUtils equalsConstantTime

Introduction

In this page you can find the example usage for io.netty.util.internal ConstantTimeUtils equalsConstantTime.

Prototype

public static int equalsConstantTime(CharSequence s1, CharSequence s2) 

Source Link

Document

Compare two CharSequence objects without leaking timing information.

Usage

From source file:io.grpc.netty.GrpcHpackUtil.java

License:Apache License

/**
 * Compare two {@link CharSequence} objects without leaking timing information.
 * <p>// ww  w. j av  a  2  s.c om
 * The {@code int} return type is intentional and is designed to allow cascading of constant time operations:
 * <pre>
 *     String s1 = "foo";
 *     String s2 = "foo";
 *     String s3 = "foo";
 *     String s4 = "goo";
 *     boolean equals = (equalsConstantTime(s1, s2) & equalsConstantTime(s3, s4)) != 0;
 * </pre>
 * @param s1 the first value.
 * @param s2 the second value.
 * @return {@code 0} if not equal. {@code 1} if equal.
 */
static int equalsConstantTime(CharSequence s1, CharSequence s2) {
    if (s1 instanceof AsciiString && s2 instanceof AsciiString) {
        if (s1.length() != s2.length()) {
            return 0;
        }
        AsciiString s1Ascii = (AsciiString) s1;
        AsciiString s2Ascii = (AsciiString) s2;
        return PlatformDependent.equalsConstantTime(s1Ascii.array(), s1Ascii.arrayOffset(), s2Ascii.array(),
                s2Ascii.arrayOffset(), s1.length());
    }

    return ConstantTimeUtils.equalsConstantTime(s1, s2);
}

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