HBASE-18972 Use Builder pattern to remove nullable parameters for coprocessor methods in RawAsyncTable interface

hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncTable.java

@@ -38,11 +38,6 @@ import com.google.protobuf.RpcController;
  * <p>
  * So, only experts that want to build high performance service should use this interface directly,
  * especially for the {@link #scan(Scan, RawScanResultConsumer)} below.
- * <p>
- * TODO: For now the only difference between this interface and {@link AsyncTable} is the scan
- * method. The {@link RawScanResultConsumer} exposes the implementation details of a scan(heartbeat)
- * so it is not suitable for a normal user. If it is still the only difference after we implement
- * most features of AsyncTable, we can think about merge these two interfaces.
  * @since 2.0.0
  */
 @InterfaceAudience.Public
@@ -135,8 +130,8 @@ public interface RawAsyncTable extends AsyncTableBase {
    * the rpc calls, so we need an {@link #onComplete()} which is used to tell you that we have
    * passed all the return values to you(through the {@link #onRegionComplete(RegionInfo, Object)}
    * or {@link #onRegionError(RegionInfo, Throwable)} calls), i.e, there will be no
-   * {@link #onRegionComplete(RegionInfo, Object)} or
+   * {@link #onRegionComplete(RegionInfo, Object)} or {@link #onRegionError(RegionInfo, Throwable)}
-   * {@link #onRegionError(RegionInfo, Throwable)} calls in the future.
+   * calls in the future.
    * <p>
    * Here is a pseudo code to describe a typical implementation of a range coprocessor service
    * method to help you better understand how the {@link CoprocessorCallback} will be called. The
@@ -200,25 +195,56 @@ public interface RawAsyncTable extends AsyncTableBase {
   }
 
   /**
-   * Execute the given coprocessor call on the regions which are covered by the range from
+   * Helper class for sending coprocessorService request that executes a coprocessor call on regions
-   * {@code startKey} inclusive and {@code endKey} exclusive. See the comment of
+   * which are covered by a range.
-   * {@link #coprocessorService(Function, CoprocessorCallable, byte[], boolean, byte[], boolean, CoprocessorCallback)}
+   * <p>
-   * for more details.
+   * If {@code fromRow} is not specified the selection will start with the first table region. If
-   * @see #coprocessorService(Function, CoprocessorCallable, byte[], boolean, byte[], boolean,
+   * {@code toRow} is not specified the selection will continue through the last table region.
-   *      CoprocessorCallback)
+   * @param <S> the type of the protobuf Service you want to call.
+   * @param <R> the type of the return value.
    */
-  default <S, R> void coprocessorService(Function<RpcChannel, S> stubMaker,
+  interface CoprocessorServiceBuilder<S, R> {
-      CoprocessorCallable<S, R> callable, byte[] startKey, byte[] endKey,
+
-      CoprocessorCallback<R> callback) {
+    /**
-    coprocessorService(stubMaker, callable, startKey, true, endKey, false, callback);
+     * @param startKey start region selection with region containing this row, inclusive.
+     */
+    default CoprocessorServiceBuilder<S, R> fromRow(byte[] startKey) {
+      return fromRow(startKey, true);
+    }
+
+    /**
+     * @param startKey start region selection with region containing this row
+     * @param inclusive whether to include the startKey
+     */
+    CoprocessorServiceBuilder<S, R> fromRow(byte[] startKey, boolean inclusive);
+
+    /**
+     * @param endKey select regions up to and including the region containing this row, exclusive.
+     */
+    default CoprocessorServiceBuilder<S, R> toRow(byte[] endKey) {
+      return toRow(endKey, false);
+    }
+
+    /**
+     * @param endKey select regions up to and including the region containing this row
+     * @param inclusive whether to include the endKey
+     */
+    CoprocessorServiceBuilder<S, R> toRow(byte[] endKey, boolean inclusive);
+
+    /**
+     * Execute the coprocessorService request. You can get the response through the
+     * {@link CoprocessorCallback}.
+     */
+    void execute();
   }
 
   /**
-   * Execute the given coprocessor call on the regions which are covered by the range from
+   * Execute a coprocessor call on the regions which are covered by a range.
-   * {@code startKey} and {@code endKey}. The inclusive of boundaries are specified by
+   * <p>
-   * {@code startKeyInclusive} and {@code endKeyInclusive}. The {@code stubMaker} is just a
+   * Use the returned {@link CoprocessorServiceBuilder} construct your request and then execute it.
-   * delegation to the {@code xxxService.newStub} call. Usually it is only a one line lambda
+   * <p>
-   * expression, like:
+   * The {@code stubMaker} is just a delegation to the {@code xxxService.newStub} call. Usually it
+   * is only a one line lambda expression, like:
    *
    * <pre>
    * <code>
@@ -229,20 +255,9 @@ public interface RawAsyncTable extends AsyncTableBase {
    * @param stubMaker a delegation to the actual {@code newStub} call.
    * @param callable a delegation to the actual protobuf rpc call. See the comment of
    *          {@link CoprocessorCallable} for more details.
-   * @param startKey start region selection with region containing this row. If {@code null}, the
-   *          selection will start with the first table region.
-   * @param startKeyInclusive whether to include the startKey
-   * @param endKey select regions up to and including the region containing this row. If
-   *          {@code null}, selection will continue through the last table region.
-   * @param endKeyInclusive whether to include the endKey
    * @param callback callback to get the response. See the comment of {@link CoprocessorCallback}
    *          for more details.
-   * @param <S> the type of the asynchronous stub
-   * @param <R> the type of the return value
-   * @see CoprocessorCallable
-   * @see CoprocessorCallback
    */
-  <S, R> void coprocessorService(Function<RpcChannel, S> stubMaker,
+  <S, R> CoprocessorServiceBuilder<S, R> coprocessorService(Function<RpcChannel, S> stubMaker,
-      CoprocessorCallable<S, R> callable, byte[] startKey, boolean startKeyInclusive, byte[] endKey,
+      CoprocessorCallable<S, R> callable, CoprocessorCallback<R> callback);
-      boolean endKeyInclusive, CoprocessorCallback<R> callback);
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncTableImpl.java

@@ -18,8 +18,6 @@
 package org.apache.hadoop.hbase.client;
 
 import static java.util.stream.Collectors.toList;
-import static org.apache.hadoop.hbase.HConstants.EMPTY_END_ROW;
-import static org.apache.hadoop.hbase.HConstants.EMPTY_START_ROW;
 import static org.apache.hadoop.hbase.client.ConnectionUtils.checkHasFamilies;
 import static org.apache.hadoop.hbase.client.ConnectionUtils.isEmptyStopRow;
 
@@ -29,7 +27,6 @@ import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
-import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -38,6 +35,7 @@ import java.util.function.Function;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.CompareOperator;
+import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.HRegionLocation;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.AsyncRpcRetryingCallerFactory.SingleRequestCallerBuilder;
@@ -560,19 +558,64 @@ class RawAsyncTableImpl implements RawAsyncTable {
     });
   }
 
-  @Override
+  private final class CoprocessorServiceBuilderImpl<S, R>
-  public <S, R> void coprocessorService(Function<RpcChannel, S> stubMaker,
+      implements CoprocessorServiceBuilder<S, R> {
-      CoprocessorCallable<S, R> callable, byte[] startKey, boolean startKeyInclusive, byte[] endKey,
+
-      boolean endKeyInclusive, CoprocessorCallback<R> callback) {
+    private final Function<RpcChannel, S> stubMaker;
-    byte[] nonNullStartKey = Optional.ofNullable(startKey).orElse(EMPTY_START_ROW);
+
-    byte[] nonNullEndKey = Optional.ofNullable(endKey).orElse(EMPTY_END_ROW);
+    private final CoprocessorCallable<S, R> callable;
-    List<HRegionLocation> locs = new ArrayList<>();
+
-    conn.getLocator()
+    private final CoprocessorCallback<R> callback;
-        .getRegionLocation(tableName, nonNullStartKey,
+
-          startKeyInclusive ? RegionLocateType.CURRENT : RegionLocateType.AFTER, operationTimeoutNs)
+    private byte[] startKey = HConstants.EMPTY_START_ROW;
-        .whenComplete(
+
-          (loc, error) -> onLocateComplete(stubMaker, callable, callback, locs, nonNullEndKey,
+    private boolean startKeyInclusive;
-            endKeyInclusive, new AtomicBoolean(false), new AtomicInteger(0), loc, error));
+
+    private byte[] endKey = HConstants.EMPTY_END_ROW;
+
+    private boolean endKeyInclusive;
+
+    public CoprocessorServiceBuilderImpl(Function<RpcChannel, S> stubMaker,
+        CoprocessorCallable<S, R> callable, CoprocessorCallback<R> callback) {
+      this.stubMaker = Preconditions.checkNotNull(stubMaker, "stubMaker is null");
+      this.callable = Preconditions.checkNotNull(callable, "callable is null");
+      this.callback = Preconditions.checkNotNull(callback, "callback is null");
+    }
+
+    @Override
+    public CoprocessorServiceBuilderImpl<S, R> fromRow(byte[] startKey, boolean inclusive) {
+      this.startKey = Preconditions.checkNotNull(startKey,
+        "startKey is null. Consider using" +
+            " an empty byte array, or just do not call this method if you want to start selection" +
+            " from the first region");
+      this.startKeyInclusive = inclusive;
+      return this;
+    }
+
+    @Override
+    public CoprocessorServiceBuilderImpl<S, R> toRow(byte[] endKey, boolean inclusive) {
+      this.endKey = Preconditions.checkNotNull(endKey,
+        "endKey is null. Consider using" +
+            " an empty byte array, or just do not call this method if you want to continue" +
+            " selection to the last region");
+      this.endKeyInclusive = inclusive;
+      return this;
+    }
+
+    @Override
+    public void execute() {
+      conn.getLocator().getRegionLocation(tableName, startKey,
+        startKeyInclusive ? RegionLocateType.CURRENT : RegionLocateType.AFTER, operationTimeoutNs)
+          .whenComplete(
+            (loc, error) -> onLocateComplete(stubMaker, callable, callback, new ArrayList<>(),
+              endKey, endKeyInclusive, new AtomicBoolean(false), new AtomicInteger(0), loc, error));
+    }
   }
 
+  @Override
+  public <S, R> CoprocessorServiceBuilder<S, R> coprocessorService(
+      Function<RpcChannel, S> stubMaker, CoprocessorCallable<S, R> callable,
+      CoprocessorCallback<R> callback) {
+    return new CoprocessorServiceBuilderImpl<>(stubMaker, callable, callback);
+  }
 }

hbase-endpoint/src/main/java/org/apache/hadoop/hbase/client/coprocessor/AsyncAggregationClient.java

@@ -20,6 +20,8 @@ package org.apache.hadoop.hbase.client.coprocessor;
 import static org.apache.hadoop.hbase.client.coprocessor.AggregationHelper.getParsedGenericInstance;
 import static org.apache.hadoop.hbase.client.coprocessor.AggregationHelper.validateArgAndGetPB;
 
+import com.google.protobuf.Message;
+
 import java.io.IOException;
 import java.util.Map;
 import java.util.NavigableMap;
@@ -29,6 +31,7 @@ import java.util.TreeMap;
 import java.util.concurrent.CompletableFuture;
 
 import org.apache.hadoop.hbase.Cell;
+import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.client.RawAsyncTable;
 import org.apache.hadoop.hbase.client.RawAsyncTable.CoprocessorCallback;
 import org.apache.hadoop.hbase.client.RawScanResultConsumer;
@@ -43,8 +46,6 @@ import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.ReflectionUtils;
 import org.apache.yetus.audience.InterfaceAudience;
 
-import com.google.protobuf.Message;
-
 /**
  * This client class is for invoking the aggregate functions deployed on the Region Server side via
  * the AggregateService. This class will implement the supporting functionality for
@@ -120,6 +121,10 @@ public class AsyncAggregationClient {
     return ci.getPromotedValueFromProto(t);
   }
 
+  private static byte[] nullToEmpty(byte[] b) {
+    return b != null ? b : HConstants.EMPTY_BYTE_ARRAY;
+  }
+
   public static <R, S, P extends Message, Q extends Message, T extends Message> CompletableFuture<R>
       max(RawAsyncTable table, ColumnInterpreter<R, S, P, Q, T> ci, Scan scan) {
     CompletableFuture<R> future = new CompletableFuture<>();
@@ -149,10 +154,11 @@ public class AsyncAggregationClient {
         return max;
       }
     };
-    table.coprocessorService(channel -> AggregateService.newStub(channel),
+    table
-      (stub, controller, rpcCallback) -> stub.getMax(controller, req, rpcCallback),
+        .<AggregateService, AggregateResponse> coprocessorService(AggregateService::newStub,
-      scan.getStartRow(), scan.includeStartRow(), scan.getStopRow(), scan.includeStopRow(),
+          (stub, controller, rpcCallback) -> stub.getMax(controller, req, rpcCallback), callback)
-      callback);
+        .fromRow(nullToEmpty(scan.getStartRow()), scan.includeStartRow())
+        .toRow(nullToEmpty(scan.getStopRow()), scan.includeStopRow()).execute();
     return future;
   }
 
@@ -185,10 +191,11 @@ public class AsyncAggregationClient {
         return min;
       }
     };
-    table.coprocessorService(channel -> AggregateService.newStub(channel),
+    table
-      (stub, controller, rpcCallback) -> stub.getMin(controller, req, rpcCallback),
+        .<AggregateService, AggregateResponse> coprocessorService(AggregateService::newStub,
-      scan.getStartRow(), scan.includeStartRow(), scan.getStopRow(), scan.includeStopRow(),
+          (stub, controller, rpcCallback) -> stub.getMin(controller, req, rpcCallback), callback)
-      callback);
+        .fromRow(nullToEmpty(scan.getStartRow()), scan.includeStartRow())
+        .toRow(nullToEmpty(scan.getStopRow()), scan.includeStopRow()).execute();
     return future;
   }
 
@@ -217,10 +224,11 @@ public class AsyncAggregationClient {
         return count;
       }
     };
-    table.coprocessorService(channel -> AggregateService.newStub(channel),
+    table
-      (stub, controller, rpcCallback) -> stub.getRowNum(controller, req, rpcCallback),
+        .<AggregateService, AggregateResponse> coprocessorService(AggregateService::newStub,
-      scan.getStartRow(), scan.includeStartRow(), scan.getStopRow(), scan.includeStopRow(),
+          (stub, controller, rpcCallback) -> stub.getRowNum(controller, req, rpcCallback), callback)
-      callback);
+        .fromRow(nullToEmpty(scan.getStartRow()), scan.includeStartRow())
+        .toRow(nullToEmpty(scan.getStopRow()), scan.includeStopRow()).execute();
     return future;
   }
 
@@ -251,10 +259,11 @@ public class AsyncAggregationClient {
         return sum;
       }
     };
-    table.coprocessorService(channel -> AggregateService.newStub(channel),
+    table
-      (stub, controller, rpcCallback) -> stub.getSum(controller, req, rpcCallback),
+        .<AggregateService, AggregateResponse> coprocessorService(AggregateService::newStub,
-      scan.getStartRow(), scan.includeStartRow(), scan.getStopRow(), scan.includeStopRow(),
+          (stub, controller, rpcCallback) -> stub.getSum(controller, req, rpcCallback), callback)
-      callback);
+        .fromRow(nullToEmpty(scan.getStartRow()), scan.includeStartRow())
+        .toRow(nullToEmpty(scan.getStopRow()), scan.includeStopRow()).execute();
     return future;
   }
 
@@ -288,10 +297,11 @@ public class AsyncAggregationClient {
         return ci.divideForAvg(sum, count);
       }
     };
-    table.coprocessorService(channel -> AggregateService.newStub(channel),
+    table
-      (stub, controller, rpcCallback) -> stub.getAvg(controller, req, rpcCallback),
+        .<AggregateService, AggregateResponse> coprocessorService(AggregateService::newStub,
-      scan.getStartRow(), scan.includeStartRow(), scan.getStopRow(), scan.includeStopRow(),
+          (stub, controller, rpcCallback) -> stub.getAvg(controller, req, rpcCallback), callback)
-      callback);
+        .fromRow(nullToEmpty(scan.getStartRow()), scan.includeStartRow())
+        .toRow(nullToEmpty(scan.getStopRow()), scan.includeStopRow()).execute();
     return future;
   }
 
@@ -330,10 +340,11 @@ public class AsyncAggregationClient {
         return Math.sqrt(avgSq - avg * avg);
       }
     };
-    table.coprocessorService(channel -> AggregateService.newStub(channel),
+    table
-      (stub, controller, rpcCallback) -> stub.getStd(controller, req, rpcCallback),
+        .<AggregateService, AggregateResponse> coprocessorService(AggregateService::newStub,
-      scan.getStartRow(), scan.includeStartRow(), scan.getStopRow(), scan.includeStopRow(),
+          (stub, controller, rpcCallback) -> stub.getStd(controller, req, rpcCallback), callback)
-      callback);
+        .fromRow(nullToEmpty(scan.getStartRow()), scan.includeStartRow())
+        .toRow(nullToEmpty(scan.getStopRow()), scan.includeStopRow()).execute();
     return future;
   }
 
@@ -368,10 +379,11 @@ public class AsyncAggregationClient {
             return map;
           }
         };
-    table.coprocessorService(channel -> AggregateService.newStub(channel),
+    table
-      (stub, controller, rpcCallback) -> stub.getMedian(controller, req, rpcCallback),
+        .<AggregateService, AggregateResponse> coprocessorService(AggregateService::newStub,
-      scan.getStartRow(), scan.includeStartRow(), scan.getStopRow(), scan.includeStopRow(),
+          (stub, controller, rpcCallback) -> stub.getMedian(controller, req, rpcCallback), callback)
-      callback);
+        .fromRow(nullToEmpty(scan.getStartRow()), scan.includeStartRow())
+        .toRow(nullToEmpty(scan.getStopRow()), scan.includeStopRow()).execute();
     return future;
   }