com.amazonaws.http.ExecutionContext.java Source code

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/*
 * Copyright 2011-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *  http://aws.amazon.com/apache2.0
 *
 * or in the "license" file accompanying this file. This file is distributed
 * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. See the License for the specific language governing
 * permissions and limitations under the License.
 */
package com.amazonaws.http;

import com.amazonaws.AmazonWebServiceClient;
import com.amazonaws.annotation.NotThreadSafe;
import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.AWSCredentialsProvider;
import com.amazonaws.auth.Signer;
import com.amazonaws.handlers.RequestHandler2;
import com.amazonaws.http.timers.client.ClientExecutionAbortTrackerTask;
import com.amazonaws.internal.auth.NoOpSignerProvider;
import com.amazonaws.internal.auth.SignerProviderContext;
import com.amazonaws.internal.auth.SignerProvider;
import com.amazonaws.retry.internal.AuthErrorRetryStrategy;
import com.amazonaws.util.AWSRequestMetrics;
import com.amazonaws.util.AWSRequestMetricsFullSupport;

import java.net.URI;
import java.util.List;

/**
 * @NotThreadSafe This class should only be accessed by a single thread and be used throughout
 *                a single request lifecycle.
 */
@NotThreadSafe
public class ExecutionContext {
    private final AWSRequestMetrics awsRequestMetrics;
    private final List<RequestHandler2> requestHandler2s;
    private final AmazonWebServiceClient awsClient;
    private final SignerProvider signerProvider;

    private boolean retryCapacityConsumed;

    /**
     * Optional credentials to enable the runtime layer to handle signing requests (and resigning on
     * retries).
     */
    private AWSCredentialsProvider credentialsProvider;

    /**
     * An internal retry strategy for auth errors. This is currently only used by the S3 client for
     * auto-resolving V4-required regions.
     */
    private AuthErrorRetryStrategy authErrorRetryStrategy;

    private ClientExecutionAbortTrackerTask clientExecutionTrackerTask;

    /** For testing purposes. */
    public ExecutionContext(boolean isMetricEnabled) {
        this(builder().withUseRequestMetrics(isMetricEnabled).withSignerProvider(new NoOpSignerProvider()));
    }

    /** For testing purposes. */
    public ExecutionContext() {
        this(builder().withSignerProvider(new NoOpSignerProvider()));
    }

    @Deprecated
    public ExecutionContext(List<RequestHandler2> requestHandler2s, boolean isMetricEnabled,
            AmazonWebServiceClient awsClient) {
        this.requestHandler2s = requestHandler2s;
        awsRequestMetrics = isMetricEnabled ? new AWSRequestMetricsFullSupport() : new AWSRequestMetrics();
        this.awsClient = awsClient;
        this.signerProvider = new SignerProvider() {
            @Override
            public Signer getSigner(SignerProviderContext context) {
                return getSignerByURI(context.getUri());
            }
        };
    }

    private ExecutionContext(final Builder builder) {
        this.requestHandler2s = builder.requestHandler2s;
        this.awsRequestMetrics = builder.useRequestMetrics ? new AWSRequestMetricsFullSupport()
                : new AWSRequestMetrics();
        this.awsClient = builder.awsClient;
        this.signerProvider = builder.signerProvider;
    }

    public List<RequestHandler2> getRequestHandler2s() {
        return requestHandler2s;
    }

    public AWSRequestMetrics getAwsRequestMetrics() {
        return awsRequestMetrics;
    }

    protected AmazonWebServiceClient getAwsClient() {
        return awsClient;
    }

    /**
     * There is in general no need to set the signer in the execution context, since the signer for
     * each request may differ depending on the URI of the request. The exception is S3 where the
     * signer is currently determined only when the S3 client is constructed. Hence the need for
     * this method. We may consider supporting a per request level signer determination for S3 later
     * on.
     */
    @Deprecated
    public void setSigner(Signer signer) {
    }

    /**
     * Returns whether retry capacity was consumed during this request lifecycle.
     * This can be inspected to determine whether capacity should be released if a retry succeeds.
     *
     * @return true if retry capacity was consumed
     */
    public boolean retryCapacityConsumed() {
        return retryCapacityConsumed;
    }

    /**
     * Marks that a retry during this request lifecycle has consumed retry capacity.  This is inspected
     * when determining if capacity should be released if a retry succeeds.
     */
    public void markRetryCapacityConsumed() {
        this.retryCapacityConsumed = true;
    }

    /**
     * Passes in the provided {@link SignerProviderContext} into a {@link SignerProvider} and returns
     * a {@link Signer} instance.
     */
    public Signer getSigner(SignerProviderContext context) {
        return signerProvider.getSigner(context);
    }

    /**
     * Returns the signer for the given uri. Note S3 in particular overrides this method.
     */
    @Deprecated
    public Signer getSignerByURI(URI uri) {
        return awsClient == null ? null : awsClient.getSignerByURI(uri);
    }

    /**
     * Sets the credentials provider used for fetching the credentials. The credentials fetched is
     * used for signing the request. If there is no credential provider, then the runtime will not
     * attempt to sign (or resign on retries) requests.
     *
     * @param credentialsProvider
     *            the credentials provider to fetch {@link AWSCredentials}
     */
    public void setCredentialsProvider(AWSCredentialsProvider credentialsProvider) {
        this.credentialsProvider = credentialsProvider;
    }

    /**
     * Returns the credentials provider used for fetching the credentials. The credentials fetched
     * is used for signing the request. If there is no credential provider, then the runtime will
     * not attempt to sign (or resign on retries) requests.
     *
     * @return the credentials provider to fetch {@link AWSCredentials}
     */
    public AWSCredentialsProvider getCredentialsProvider() {
        return this.credentialsProvider;
    }

    /**
     * Returns the retry strategy for auth errors. This is currently only used by the S3 client for
     * auto-resolving sigv4-required regions.
     * <p>
     * Note that this will be checked BEFORE the HTTP client consults the user-specified
     * RetryPolicy. i.e. if the configured AuthErrorRetryStrategy says the request should be
     * retried, the retry will be performed internally and the effect is transparent to the user's
     * RetryPolicy.
     */
    public AuthErrorRetryStrategy getAuthErrorRetryStrategy() {
        return authErrorRetryStrategy;
    }

    /**
     * Sets the optional auth error retry strategy for this request execution.
     *
     * @see #getAuthErrorRetryStrategy()
     */
    public void setAuthErrorRetryStrategy(AuthErrorRetryStrategy authErrorRetryStrategy) {
        this.authErrorRetryStrategy = authErrorRetryStrategy;
    }

    public ClientExecutionAbortTrackerTask getClientExecutionTrackerTask() {
        return clientExecutionTrackerTask;
    }

    public void setClientExecutionTrackerTask(ClientExecutionAbortTrackerTask clientExecutionTrackerTask) {
        this.clientExecutionTrackerTask = clientExecutionTrackerTask;
    }

    public static ExecutionContext.Builder builder() {
        return new ExecutionContext.Builder();
    }

    public static class Builder {

        private boolean useRequestMetrics;
        private List<RequestHandler2> requestHandler2s;
        private AmazonWebServiceClient awsClient;
        private SignerProvider signerProvider = new NoOpSignerProvider();

        private Builder() {
        }

        public boolean useRequestMetrics() {
            return useRequestMetrics;
        }

        public void setUseRequestMetrics(final boolean useRequestMetrics) {
            this.useRequestMetrics = useRequestMetrics;
        }

        public Builder withUseRequestMetrics(final boolean withUseRequestMetrics) {
            setUseRequestMetrics(withUseRequestMetrics);
            return this;
        }

        public List<RequestHandler2> getRequestHandler2s() {
            return requestHandler2s;
        }

        public void setRequestHandler2s(final List<RequestHandler2> requestHandler2s) {
            this.requestHandler2s = requestHandler2s;
        }

        public Builder withRequestHandler2s(final List<RequestHandler2> requestHandler2s) {
            setRequestHandler2s(requestHandler2s);
            return this;
        }

        public AmazonWebServiceClient getAwsClient() {
            return awsClient;
        }

        public void setAwsClient(final AmazonWebServiceClient awsClient) {
            this.awsClient = awsClient;
        }

        public Builder withAwsClient(final AmazonWebServiceClient awsClient) {
            setAwsClient(awsClient);
            return this;
        }

        public SignerProvider getSignerProvider() {
            return signerProvider;
        }

        public void setSignerProvider(final SignerProvider signerProvider) {
            this.signerProvider = signerProvider;
        }

        public Builder withSignerProvider(final SignerProvider signerProvider) {
            setSignerProvider(signerProvider);
            return this;
        }

        public ExecutionContext build() {
            return new ExecutionContext(this);
        }

    }

}