Merge pull request #516 from mziccard/bigquery-functional-classes

Add functional classes for BigQuery datasets jobs and tables

gcloud-java-bigquery/src/main/java/com/google/gcloud/bigquery/Dataset.java

@@ -0,0 +1,287 @@
+/*
+ * Copyright 2015 Google Inc. 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.
+ * 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.google.gcloud.bigquery;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import com.google.common.base.Function;
+import com.google.common.collect.Iterators;
+import com.google.gcloud.Page;
+import com.google.gcloud.PageImpl;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.Serializable;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * A Google BigQuery Dataset.
+ *
+ * <p>Objects of this class are immutable. Operations that modify the dataset like {@link #update}
+ * return a new object. To get a {@code Dataset} object with the most recent information use
+ * {@link #reload}.
+ * </p>
+ */
+public final class Dataset {
+
+  private final BigQuery bigquery;
+  private final DatasetInfo info;
+
+  private static class TablePageFetcher implements PageImpl.NextPageFetcher<Table> {
+
+    private static final long serialVersionUID = 6906197848579250598L;
+
+    private final BigQueryOptions options;
+    private final Page<BaseTableInfo> infoPage;
+
+    TablePageFetcher(BigQueryOptions options, Page<BaseTableInfo> infoPage) {
+      this.options = options;
+      this.infoPage = infoPage;
+    }
+
+    @Override
+    public Page<Table> nextPage() {
+      Page<BaseTableInfo> nextInfoPage = infoPage.nextPage();
+      return new PageImpl<>(new TablePageFetcher(options, nextInfoPage),
+          nextInfoPage.nextPageCursor(), new LazyTableIterable(options, nextInfoPage.values()));
+    }
+  }
+
+  private static class LazyTableIterable implements Iterable<Table>, Serializable {
+
+    private static final long serialVersionUID = 3312744215731674032L;
+
+    private final BigQueryOptions options;
+    private Iterable<BaseTableInfo> infoIterable;
+    private transient BigQuery bigquery;
+
+    public LazyTableIterable(BigQueryOptions options, Iterable<BaseTableInfo> infoIterable) {
+      this.options = options;
+      this.infoIterable = infoIterable;
+      this.bigquery = options.service();
+    }
+
+    private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
+      in.defaultReadObject();
+      this.bigquery = options.service();
+    }
+
+    @Override
+    public Iterator<Table> iterator() {
+      return Iterators.transform(infoIterable.iterator(), new Function<BaseTableInfo, Table>() {
+        @Override
+        public Table apply(BaseTableInfo tableInfo) {
+          return new Table(bigquery, tableInfo);
+        }
+      });
+    }
+
+    @Override
+    public int hashCode() {
+      return Objects.hash(options, infoIterable);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+      if (!(obj instanceof LazyTableIterable)) {
+        return false;
+      }
+      LazyTableIterable other = (LazyTableIterable) obj;
+      return Objects.equals(options, other.options)
+          && Objects.equals(infoIterable, other.infoIterable);
+    }
+  }
+
+  /**
+   * Constructs a {@code Dataset} object for the provided {@code DatasetInfo}. The BigQuery service
+   * is used to issue requests.
+   *
+   * @param bigquery the BigQuery service used for issuing requests
+   * @param info dataset's info
+   */
+  public Dataset(BigQuery bigquery, DatasetInfo info) {
+    this.bigquery = checkNotNull(bigquery);
+    this.info = checkNotNull(info);
+  }
+
+  /**
+   * Creates a {@code Dataset} object for the provided dataset's user-defined id. Performs an RPC
+   * call to get the latest dataset information.
+   *
+   * @param bigquery the BigQuery service used for issuing requests
+   * @param dataset dataset's user-defined id
+   * @param options dataset options
+   * @return the {@code Dataset} object or {@code null} if not found
+   * @throws BigQueryException upon failure
+   */
+  public static Dataset load(BigQuery bigquery, String dataset, BigQuery.DatasetOption... options) {
+    DatasetInfo info = bigquery.getDataset(dataset, options);
+    return info != null ? new Dataset(bigquery, info) : null;
+  }
+
+  /**
+   * Returns the dataset's information.
+   */
+  public DatasetInfo info() {
+    return info;
+  }
+
+  /**
+   * Checks if this dataset exists.
+   *
+   * @return {@code true} if this dataset exists, {@code false} otherwise
+   * @throws BigQueryException upon failure
+   */
+  public boolean exists() {
+    return bigquery.getDataset(info.datasetId(), BigQuery.DatasetOption.fields()) != null;
+  }
+
+  /**
+   * Fetches current dataset's latest information. Returns {@code null} if the dataset does not
+   * exist.
+   *
+   * @param options dataset options
+   * @return a {@code Dataset} object with latest information or {@code null} if not found
+   * @throws BigQueryException upon failure
+   */
+  public Dataset reload(BigQuery.DatasetOption... options) {
+    return Dataset.load(bigquery, info.datasetId().dataset(), options);
+  }
+
+  /**
+   * Updates the dataset's information. Dataset's user-defined id cannot be changed. A new
+   * {@code Dataset} object is returned.
+   *
+   * @param datasetInfo new dataset's information. User-defined id must match the one of the current
+   *     dataset
+   * @param options dataset options
+   * @return a {@code Dataset} object with updated information
+   * @throws BigQueryException upon failure
+   */
+  public Dataset update(DatasetInfo datasetInfo, BigQuery.DatasetOption... options) {
+    checkArgument(Objects.equals(datasetInfo.datasetId().dataset(),
+        info.datasetId().dataset()), "Dataset's user-defined ids must match");
+    return new Dataset(bigquery, bigquery.update(datasetInfo, options));
+  }
+
+  /**
+   * Deletes this dataset.
+   *
+   * @return {@code true} if dataset was deleted, {@code false} if it was not found.
+   * @throws BigQueryException upon failure
+   */
+  public boolean delete() {
+    return bigquery.delete(info.datasetId());
+  }
+
+  /**
+   * Returns the paginated list of tables in this dataset.
+   *
+   * @param options options for listing tables
+   * @throws BigQueryException upon failure
+   */
+  public Page<Table> list(BigQuery.TableListOption... options) {
+    Page<BaseTableInfo> infoPage = bigquery.listTables(info.datasetId(), options);
+    BigQueryOptions bigqueryOptions = bigquery.options();
+    return new PageImpl<>(new TablePageFetcher(bigqueryOptions, infoPage),
+        infoPage.nextPageCursor(), new LazyTableIterable(bigqueryOptions, infoPage.values()));
+  }
+
+  /**
+   * Returns the requested table in this dataset or {@code null} if not found.
+   *
+   * @param table user-defined id of the requested table
+   * @param options table options
+   * @throws BigQueryException upon failure
+   */
+  public Table get(String table, BigQuery.TableOption... options) {
+    BaseTableInfo tableInfo =
+        bigquery.getTable(TableId.of(info.datasetId().dataset(), table), options);
+    return tableInfo != null ? new Table(bigquery, tableInfo) : null;
+  }
+
+  /**
+   * Creates a new simple table in this dataset.
+   *
+   * @param table the table's user-defined id
+   * @param schema the table's schema
+   * @param options options for table creation
+   * @return a {@code Table} object for the created table
+   * @throws BigQueryException upon failure
+   */
+  public Table create(String table, Schema schema, BigQuery.TableOption... options) {
+    BaseTableInfo tableInfo = TableInfo.of(TableId.of(info.datasetId().dataset(), table), schema);
+    return new Table(bigquery, bigquery.create(tableInfo, options));
+  }
+
+  /**
+   * Creates a new view table in this dataset.
+   *
+   * @param table the table's user-defined id
+   * @param query the query used to generate the table
+   * @param functions user-defined functions that can be used by the query
+   * @param options options for table creation
+   * @return a {@code Table} object for the created table
+   * @throws BigQueryException upon failure
+   */
+  public Table create(String table, String query, List<UserDefinedFunction> functions,
+      BigQuery.TableOption... options) {
+    BaseTableInfo tableInfo =
+        ViewInfo.of(TableId.of(info.datasetId().dataset(), table), query, functions);
+    return new Table(bigquery, bigquery.create(tableInfo, options));
+  }
+
+  /**
+   * Creates a new view table in this dataset.
+   *
+   * @param table the table's user-defined id
+   * @param query the query used to generate the table
+   * @param options options for table creation
+   * @return a {@code Table} object for the created table
+   * @throws BigQueryException upon failure
+   */
+  public Table create(String table, String query, BigQuery.TableOption... options) {
+    BaseTableInfo tableInfo =  ViewInfo.of(TableId.of(info.datasetId().dataset(), table), query);
+    return new Table(bigquery, bigquery.create(tableInfo, options));
+  }
+
+  /**
+   * Creates a new external table in this dataset.
+   *
+   * @param table the table's user-defined id
+   * @param configuration data format, location and other properties of an external table
+   * @param options options for table creation
+   * @return a {@code Table} object for the created table
+   * @throws BigQueryException upon failure
+   */
+  public Table create(String table, ExternalDataConfiguration configuration,
+      BigQuery.TableOption... options) {
+    BaseTableInfo tableInfo =
+        ExternalTableInfo.of(TableId.of(info.datasetId().dataset(), table), configuration);
+    return new Table(bigquery, bigquery.create(tableInfo, options));
+  }
+
+  /**
+   * Returns the dataset's {@code BigQuery} object used to issue requests.
+   */
+  public BigQuery bigquery() {
+    return bigquery;
+  }
+}