feat: Adding CDC Sample

samples/snippets/src/main/java/com/example/bigquerystorage/AppendCompleteCallback.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2023 Google LLC
+ *
+ * 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.example;
+
+import com.google.api.core.ApiFuture;
+import com.google.api.core.ApiFutureCallback;
+import com.google.api.core.ApiFutures;
+import com.google.cloud.bigquery.BigQuery;
+import com.google.cloud.bigquery.BigQueryOptions;
+import com.google.cloud.bigquery.Field;
+import com.google.cloud.bigquery.FieldList;
+import com.google.cloud.bigquery.Schema;
+import com.google.cloud.bigquery.StandardSQLTypeName;
+import com.google.cloud.bigquery.StandardTableDefinition;
+import com.google.cloud.bigquery.Table;
+import com.google.cloud.bigquery.TableId;
+import com.google.cloud.bigquery.TableInfo;
+import com.google.cloud.bigquery.storage.v1.AppendRowsResponse;
+import com.google.cloud.bigquery.storage.v1.JsonStreamWriter;
+import com.google.cloud.bigquery.storage.v1.TableName;
+import com.google.cloud.bigquery.storage.v1.TableSchema;
+import com.google.common.util.concurrent.MoreExecutors;
+import com.google.protobuf.Descriptors.DescriptorValidationException;
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
+import org.json.JSONArray;
+import org.json.JSONObject;
+
+class AppendCompleteCallback implements ApiFutureCallback<AppendRowsResponse> {
+  private static final Object lock = new Object();
+  private static int batchCount = 0;
+
+  public void onSuccess(AppendRowsResponse response) {
+    synchronized (lock) {
+      if (response.hasError()) {
+        System.out.format("Error: %s\n", response.getError());
+      } else {
+        ++batchCount;
+        System.out.format("Wrote batch %d\n", batchCount);
+      }
+    }
+  }
+
+  public void onFailure(Throwable throwable) {
+    System.out.format("Error: %s\n", throwable.toString());
+  }
+}

samples/snippets/src/main/java/com/example/bigquerystorage/JsonWriterStreamCdc.java

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+/*
+ * Copyright 2023 Google LLC
+ *
+ * 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.example;
+
+import com.google.api.core.ApiFuture;
+import com.google.api.core.ApiFutureCallback;
+import com.google.api.core.ApiFutures;
+import com.google.cloud.bigquery.BigQuery;
+import com.google.cloud.bigquery.BigQueryOptions;
+import com.google.cloud.bigquery.Field;
+import com.google.cloud.bigquery.FieldList;
+import com.google.cloud.bigquery.Schema;
+import com.google.cloud.bigquery.StandardSQLTypeName;
+import com.google.cloud.bigquery.StandardTableDefinition;
+import com.google.cloud.bigquery.Table;
+import com.google.cloud.bigquery.TableId;
+import com.google.cloud.bigquery.TableInfo;
+import com.google.cloud.bigquery.storage.v1.AppendRowsResponse;
+import com.google.cloud.bigquery.storage.v1.JsonStreamWriter;
+import com.google.cloud.bigquery.storage.v1.TableFieldSchema;
+import com.google.cloud.bigquery.storage.v1.TableName;
+import com.google.cloud.bigquery.storage.v1.TableSchema;
+import com.google.common.util.concurrent.MoreExecutors;
+import com.google.protobuf.Descriptors.DescriptorValidationException;
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
+import org.json.JSONArray;
+import org.json.JSONObject;
+
+public class JsonWriterStreamCdc {
+
+  private static final String CHANGE_TYPE_PSEUDO_COLUMN = "_change_type";
+
+  public static void main(String[] args) throws Exception {
+    if (args.length < 4) {
+      System.out.println("Arguments: project, dataset, table, source_file");
+      return;
+    }
+
+    String projectId = args[0];
+    String datasetName = args[1];
+    String tableName = args[2];
+    String dataFile = args[3];
+    createDestinationTable(projectId, datasetName, tableName);
+    writeToDefaultStream(projectId, datasetName, tableName, dataFile);
+  }
+
+  public static void createDestinationTable(
+          String projectId, String datasetName, String tableName) {
+    BigQuery bigquery = BigQueryOptions.getDefaultInstance().getService();
+    // Create a schema that matches the source data.
+    Schema schema =
+            Schema.of(
+                    Field.of("commit", StandardSQLTypeName.STRING),
+                    Field.newBuilder("parent", StandardSQLTypeName.STRING)
+                            .setMode(Field.Mode.REPEATED)
+                            .build(),
+                    Field.of("author", StandardSQLTypeName.STRING),
+                    Field.of("committer", StandardSQLTypeName.STRING),
+                    Field.of("commit_date", StandardSQLTypeName.DATETIME),
+                    Field.of(
+                            "commit_msg",
+                            StandardSQLTypeName.STRUCT,
+                            FieldList.of(
+                                    Field.of("subject", StandardSQLTypeName.STRING),
+                                    Field.of("message", StandardSQLTypeName.STRING))),
+                    Field.of("repo_name", StandardSQLTypeName.STRING));
+
+    // Create a table that uses this schema.
+    TableId tableId = TableId.of(projectId, datasetName, tableName);
+    Table table = bigquery.getTable(tableId);
+    if (table == null) {
+      TableInfo tableInfo =
+              TableInfo.newBuilder(tableId, StandardTableDefinition.of(schema)).build();
+      bigquery.create(tableInfo);
+    }
+  }
+
+  // writeToDefaultStream: Writes records from the source file to the destination table.
+  public static void writeToDefaultStream(
+          String projectId, String datasetName, String tableName, String dataFile)
+          throws DescriptorValidationException, InterruptedException, IOException {
+
+    BigQuery bigquery = BigQueryOptions.getDefaultInstance().getService();
+
+    // Get the schema of the destination table and convert to the equivalent BigQueryStorage type.
+    Table table = bigquery.getTable(datasetName, tableName);
+    Schema schema = table.getDefinition().getSchema();
+    TableSchema tableSchema = BqToBqStorageSchemaConverter.convertTableSchema(schema);
+
+    // Use the JSON stream writer to send records in JSON format.
+    TableName parentTable = TableName.of(projectId, datasetName, tableName);
+    try (JsonStreamWriter writer =
+                 JsonStreamWriter.newBuilder(parentTable.toString(),
+                                 addPseudoColumnsIfNeeded(tableSchema))
+                         .build()) {
+      // Read JSON data from the source file and send it to the Write API.
+      BufferedReader reader = new BufferedReader(new FileReader(dataFile));
+      String line = reader.readLine();
+      while (line != null) {
+        // As a best practice, send batches of records, instead of single records at a time.
+        JSONArray jsonArr = new JSONArray();
+        for (int i = 0; i < 100; i++) {
+          JSONObject record = new JSONObject(line);
+          jsonArr.put(record);
+          line = reader.readLine();
+          if (line == null) {
+            break;
+          }
+        } // batch
+        ApiFuture<AppendRowsResponse> future = writer.append(jsonArr);
+        // The append method is asynchronous. Rather than waiting for the method to complete,
+        // which can hurt performance, register a completion callback and continue streaming.
+        ApiFutures.addCallback(
+                future, new AppendCompleteCallback(), MoreExecutors.directExecutor());
+      }
+    }
+  }
+
+  private static TableSchema addPseudoColumnsIfNeeded(TableSchema tableSchema) {
+    return tableSchema
+            .toBuilder()
+            .addFields(
+                    TableFieldSchema.newBuilder()
+                            .setType(TableFieldSchema.Type.STRING)
+                            .setMode(TableFieldSchema.Mode.NULLABLE)
+                            .build())
+            .addFields(
+                    TableFieldSchema.newBuilder()
+                            .setName(CHANGE_TYPE_PSEUDO_COLUMN)
+                            .setType(TableFieldSchema.Type.STRING)
+                            .setMode(TableFieldSchema.Mode.NULLABLE)
+                            .build())
+            .build();
+  }
+}