TestSizeLimitedResponseReader

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package org.apache.http.impl.client.cache;

import java.io.IOException;
import java.lang.reflect.Proxy;
import java.util.concurrent.atomic.AtomicBoolean;

import org.apache.http.HttpEntity;
import org.apache.http.HttpRequest;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.HttpVersion;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.entity.ByteArrayEntity;
import org.apache.http.entity.StringEntity;
import org.apache.http.message.BasicHttpResponse;
import org.apache.http.util.EntityUtils;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

public class TestSizeLimitedResponseReader {

    private static final long MAX_SIZE = 4;

    private HttpRequest request;
    private SizeLimitedResponseReader impl;

    @Before
    public void setUp() {
        request = new HttpGet("http://foo.example.com/bar");
    }

    @Test
    public void testLargeResponseIsTooLarge() throws Exception {
        final byte[] buf = new byte[] { 1, 2, 3, 4, 5 };
        final CloseableHttpResponse response = make200Response(buf);

        impl = new SizeLimitedResponseReader(new HeapResourceFactory(), MAX_SIZE, request, response);

        impl.readResponse();
        final boolean tooLarge = impl.isLimitReached();
        final HttpResponse result = impl.getReconstructedResponse();
        final byte[] body = EntityUtils.toByteArray(result.getEntity());

        Assert.assertTrue(tooLarge);
        Assert.assertArrayEquals(buf, body);
    }

    @Test
    public void testExactSizeResponseIsNotTooLarge() throws Exception {
        final byte[] buf = new byte[] { 1, 2, 3, 4 };
        final CloseableHttpResponse response = make200Response(buf);

        impl = new SizeLimitedResponseReader(new HeapResourceFactory(), MAX_SIZE, request, response);

        impl.readResponse();
        final boolean tooLarge = impl.isLimitReached();
        final HttpResponse reconstructed = impl.getReconstructedResponse();
        final byte[] result = EntityUtils.toByteArray(reconstructed.getEntity());

        Assert.assertFalse(tooLarge);
        Assert.assertArrayEquals(buf, result);
    }

    @Test
    public void testSmallResponseIsNotTooLarge() throws Exception {
        final byte[] buf = new byte[] { 1, 2, 3 };
        final CloseableHttpResponse response = make200Response(buf);

        impl = new SizeLimitedResponseReader(new HeapResourceFactory(), MAX_SIZE, request, response);

        impl.readResponse();
        final boolean tooLarge = impl.isLimitReached();
        final HttpResponse reconstructed = impl.getReconstructedResponse();
        final byte[] result = EntityUtils.toByteArray(reconstructed.getEntity());

        Assert.assertFalse(tooLarge);
        Assert.assertArrayEquals(buf, result);
    }

    @Test
    public void testResponseWithNoEntityIsNotTooLarge() throws Exception {
        final CloseableHttpResponse response = make200Response();

        impl = new SizeLimitedResponseReader(new HeapResourceFactory(), MAX_SIZE, request, response);

        impl.readResponse();
        final boolean tooLarge = impl.isLimitReached();

        Assert.assertFalse(tooLarge);
    }

    @Test
    public void testTooLargeEntityHasOriginalContentTypes() throws Exception {
        final CloseableHttpResponse response = make200Response();
        final StringEntity entity = new StringEntity("large entity content");
        response.setEntity(entity);

        impl = new SizeLimitedResponseReader(new HeapResourceFactory(), MAX_SIZE, request, response);

        impl.readResponse();
        final boolean tooLarge = impl.isLimitReached();
        final HttpResponse result = impl.getReconstructedResponse();
        final HttpEntity reconstructedEntity = result.getEntity();
        Assert.assertEquals(entity.getContentEncoding(), reconstructedEntity.getContentEncoding());
        Assert.assertEquals(entity.getContentType(), reconstructedEntity.getContentType());

        final String content = EntityUtils.toString(reconstructedEntity);

        Assert.assertTrue(tooLarge);
        Assert.assertEquals("large entity content", content);
    }

    @Test
    public void testTooLargeResponseCombinedClosed() throws Exception {
        final AtomicBoolean closed = new AtomicBoolean(false);
        final CloseableHttpResponse response = (CloseableHttpResponse) Proxy
                .newProxyInstance(ResponseProxyHandler.class.getClassLoader(),
                        new Class<?>[] { CloseableHttpResponse.class },
                        new ResponseProxyHandler(new BasicHttpResponse(
                                HttpVersion.HTTP_1_1, HttpStatus.SC_OK, "OK")) {
                            @Override
                            public void close() throws IOException {
                                closed.set(true);
                            }
                        });
        final StringEntity entity = new StringEntity("large entity content");
        response.setEntity(entity);

        impl = new SizeLimitedResponseReader(new HeapResourceFactory(), MAX_SIZE, request, response);

        impl.readResponse();
        final boolean tooLarge = impl.isLimitReached();
        final CloseableHttpResponse result = impl.getReconstructedResponse();
        try {
            final HttpEntity reconstructedEntity = result.getEntity();
            Assert.assertEquals(entity.getContentEncoding(), reconstructedEntity.getContentEncoding());
            Assert.assertEquals(entity.getContentType(), reconstructedEntity.getContentType());

            Assert.assertFalse(closed.get());
            final String content = EntityUtils.toString(reconstructedEntity);

            Assert.assertTrue(tooLarge);
            Assert.assertEquals("large entity content", content);
        } finally {
            result.close();
        }
        Assert.assertTrue(closed.get());
    }

    @Test
    public void testResponseCopiesAllOriginalHeaders() throws Exception {
        final byte[] buf = new byte[] { 1, 2, 3 };
        final CloseableHttpResponse response = make200Response(buf);
        response.setHeader("Content-Encoding", "gzip");

        impl = new SizeLimitedResponseReader(new HeapResourceFactory(), MAX_SIZE, request, response);

        impl.readResponse();
        final boolean tooLarge = impl.isLimitReached();
        final HttpResponse reconstructed = impl.getReconstructedResponse();
        final byte[] result = EntityUtils.toByteArray(reconstructed.getEntity());

        Assert.assertFalse(tooLarge);
        Assert.assertArrayEquals(buf, result);
        Assert.assertEquals("gzip", reconstructed.getFirstHeader("Content-Encoding").getValue());
    }

    private CloseableHttpResponse make200Response() {
        return Proxies.enhanceResponse(new BasicHttpResponse(
                HttpVersion.HTTP_1_1, HttpStatus.SC_OK, "OK"));
    }

    private CloseableHttpResponse make200Response(final byte[] buf) {
        final HttpResponse response = new BasicHttpResponse(
                HttpVersion.HTTP_1_1, HttpStatus.SC_OK, "OK");
        response.setEntity(new ByteArrayEntity(buf));
        return Proxies.enhanceResponse(response);
    }

}