MemoryUsage.java

package io.netty.microbench.headers;

import io.netty.handler.codec.http.DefaultHttpHeaders;
import io.netty.handler.codec.http2.DefaultHttp2Headers;
import io.netty.microbench.headers.ExampleHeaders.HeaderExample;
import io.netty.util.AsciiString;
import io.netty.util.ByteString;
import io.netty.util.CharsetUtil;
import org.openjdk.jol.info.GraphLayout;

import java.util.Map;
import java.util.Map.Entry;

public class MemoryUsage {

    private static class LowerBound {
        private ByteString[] keys;
        private ByteString[] values;
        private int idx;

        public LowerBound(int size) {
            keys = new ByteString[size];
            values = new ByteString[size];
        }

        public void add(ByteString key, ByteString value) {
            keys[idx] = key;
            values[idx] = value;
            idx++;
        }
    }

    public static void main(String... args) {
        for (Entry<HeaderExample, Map<String, String>> header : ExampleHeaders.EXAMPLES.entrySet()) {
            DefaultHttpHeaders http = new DefaultHttpHeaders(false);
            DefaultHttp2Headers http2 = new DefaultHttp2Headers();
            LowerBound lower = new LowerBound(header.getValue().size());
            for (Entry<String, String> entry : header.getValue().entrySet()) {
                http.add(new AsciiString(entry.getKey()), new AsciiString(entry.getValue()));
                http2.add(new ByteString(entry.getKey(), CharsetUtil.US_ASCII), new ByteString(entry.getValue(), CharsetUtil.US_ASCII));
                lower.add(new ByteString(entry.getKey(), CharsetUtil.US_ASCII), new ByteString(entry.getValue(), CharsetUtil.US_ASCII));
            }

            System.out.println(header.getKey().toString());
            System.out.println("HTTP: " + GraphLayout.parseInstance(http).totalSize());
            System.out.println("HTTP2: " + GraphLayout.parseInstance(http2).totalSize());
            System.out.println("LOWER: " + GraphLayout.parseInstance(lower).totalSize());
        }
    }
}