NativeFunctionDefinitionProvider.java

/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License 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.facebook.presto.sidecar.functionNamespace;

import com.facebook.airlift.http.client.HttpClient;
import com.facebook.airlift.http.client.HttpUriBuilder;
import com.facebook.airlift.http.client.Request;
import com.facebook.airlift.json.JsonCodec;
import com.facebook.airlift.log.Logger;
import com.facebook.presto.functionNamespace.JsonBasedUdfFunctionMetadata;
import com.facebook.presto.functionNamespace.UdfFunctionSignatureMap;
import com.facebook.presto.sidecar.ForSidecarInfo;
import com.facebook.presto.spi.Node;
import com.facebook.presto.spi.NodeManager;
import com.facebook.presto.spi.PrestoException;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.ImmutableMap;
import com.google.inject.Inject;

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

import static com.facebook.airlift.http.client.JsonResponseHandler.createJsonResponseHandler;
import static com.facebook.airlift.http.client.Request.Builder.prepareGet;
import static com.facebook.presto.spi.StandardErrorCode.INVALID_ARGUMENTS;
import static java.util.Objects.requireNonNull;

public class NativeFunctionDefinitionProvider
        implements FunctionDefinitionProvider
{
    private static final Logger log = Logger.get(NativeFunctionDefinitionProvider.class);
    private final JsonCodec<Map<String, List<JsonBasedUdfFunctionMetadata>>> nativeFunctionSignatureMapJsonCodec;
    private final NodeManager nodeManager;
    private final HttpClient httpClient;
    private static final String FUNCTION_SIGNATURES_ENDPOINT = "/v1/functions";

    @Inject
    public NativeFunctionDefinitionProvider(
            @ForSidecarInfo HttpClient httpClient,
            JsonCodec<Map<String, List<JsonBasedUdfFunctionMetadata>>> nativeFunctionSignatureMapJsonCodec,
            NodeManager nodeManager)
    {
        this.nativeFunctionSignatureMapJsonCodec =
                requireNonNull(nativeFunctionSignatureMapJsonCodec, "nativeFunctionSignatureMapJsonCodec is null");
        this.nodeManager = requireNonNull(nodeManager, "nodeManager is null");
        this.httpClient = requireNonNull(httpClient, "typeManager is null");
    }

    @Override
    public UdfFunctionSignatureMap getUdfDefinition(NodeManager nodeManager)
    {
        try {
            Request request = prepareGet().setUri(getSidecarLocation()).build();
            Map<String, List<JsonBasedUdfFunctionMetadata>> nativeFunctionSignatureMap = httpClient.execute(request, createJsonResponseHandler(nativeFunctionSignatureMapJsonCodec));
            return new UdfFunctionSignatureMap(ImmutableMap.copyOf(nativeFunctionSignatureMap));
        }
        catch (Exception e) {
            throw new PrestoException(INVALID_ARGUMENTS, "Failed to get functions from sidecar.", e);
        }
    }

    private URI getSidecarLocation()
    {
        Node sidecarNode = nodeManager.getSidecarNode();
        return HttpUriBuilder
                .uriBuilderFrom(sidecarNode.getHttpUri())
                .appendPath(FUNCTION_SIGNATURES_ENDPOINT)
                .build();
    }

    @VisibleForTesting
    public HttpClient getHttpClient()
    {
        return httpClient;
    }
}