purbanow commented on a change in pull request #11794:
URL: https://github.com/apache/beam/pull/11794#discussion_r444031088
##########
File path:
sdks/java/io/snowflake/src/main/java/org/apache/beam/sdk/io/snowflake/SnowflakeIO.java
##########
@@ -447,6 +513,346 @@ public void populateDisplayData(DisplayData.Builder
builder) {
}
}
+ /** Implementation of {@link #write()}. */
+ @AutoValue
+ public abstract static class Write<T> extends PTransform<PCollection<T>,
PDone> {
+ @Nullable
+ abstract SerializableFunction<Void, DataSource> getDataSourceProviderFn();
+
+ @Nullable
+ abstract String getTable();
+
+ @Nullable
+ abstract String getStorageIntegrationName();
+
+ @Nullable
+ abstract String getStagingBucketName();
+
+ @Nullable
+ abstract String getQuery();
+
+ @Nullable
+ abstract String getFileNameTemplate();
+
+ @Nullable
+ abstract WriteDisposition getWriteDisposition();
+
+ @Nullable
+ abstract UserDataMapper getUserDataMapper();
+
+ @Nullable
+ abstract SnowflakeService getSnowflakeService();
+
+ abstract Builder<T> toBuilder();
+
+ @AutoValue.Builder
+ abstract static class Builder<T> {
+ abstract Builder<T> setDataSourceProviderFn(
+ SerializableFunction<Void, DataSource> dataSourceProviderFn);
+
+ abstract Builder<T> setTable(String table);
+
+ abstract Builder<T> setStorageIntegrationName(String
storageIntegrationName);
+
+ abstract Builder<T> setStagingBucketName(String stagingBucketName);
+
+ abstract Builder<T> setQuery(String query);
+
+ abstract Builder<T> setFileNameTemplate(String fileNameTemplate);
+
+ abstract Builder<T> setUserDataMapper(UserDataMapper userDataMapper);
+
+ abstract Builder<T> setWriteDisposition(WriteDisposition
writeDisposition);
+
+ abstract Builder<T> setSnowflakeService(SnowflakeService
snowflakeService);
+
+ abstract Write<T> build();
+ }
+
+ /**
+ * Setting information about Snowflake server.
+ *
+ * @param config - An instance of {@link DataSourceConfiguration}.
+ */
+ public Write<T> withDataSourceConfiguration(final DataSourceConfiguration
config) {
+ return withDataSourceProviderFn(new
DataSourceProviderFromDataSourceConfiguration(config));
+ }
+
+ /**
+ * Setting function that will provide {@link DataSourceConfiguration} in
runtime.
+ *
+ * @param dataSourceProviderFn a {@link SerializableFunction}.
+ */
+ public Write<T> withDataSourceProviderFn(
+ SerializableFunction<Void, DataSource> dataSourceProviderFn) {
+ return toBuilder().setDataSourceProviderFn(dataSourceProviderFn).build();
+ }
+
+ /**
+ * A table name to be written in Snowflake.
+ *
+ * @param table - String with the name of the table.
+ */
+ public Write<T> withTable(String table) {
+ return toBuilder().setTable(table).build();
+ }
+
+ /**
+ * Name of the cloud bucket (GCS by now) to use as tmp location of CSVs
during COPY statement.
+ *
+ * @param stagingBucketName - String with the name of the bucket.
+ */
+ public Write<T> withStagingBucketName(String stagingBucketName) {
+ return toBuilder().setStagingBucketName(stagingBucketName).build();
+ }
+
+ /**
+ * Name of the Storage Integration in Snowflake to be used. See
+ *
https://docs.snowflake.com/en/sql-reference/sql/create-storage-integration.html
for
+ * reference.
+ *
+ * @param integrationName - String with the name of the Storage
Integration.
+ */
+ public Write<T> withStorageIntegrationName(String integrationName) {
+ return toBuilder().setStorageIntegrationName(integrationName).build();
+ }
+
+ /**
+ * A query to be executed in Snowflake.
+ *
+ * @param query - String with query.
+ */
+ public Write<T> withQueryTransformation(String query) {
+ return toBuilder().setQuery(query).build();
+ }
+
+ /**
+ * A template name for files saved to GCP.
+ *
+ * @param fileNameTemplate - String with template name for files.
+ */
+ public Write<T> withFileNameTemplate(String fileNameTemplate) {
+ return toBuilder().setFileNameTemplate(fileNameTemplate).build();
+ }
+
+ /**
+ * User-defined function mapping user data into CSV lines.
+ *
+ * @param userDataMapper - an instance of {@link UserDataMapper}.
+ */
+ public Write<T> withUserDataMapper(UserDataMapper userDataMapper) {
+ return toBuilder().setUserDataMapper(userDataMapper).build();
+ }
+
+ /**
+ * A disposition to be used during writing to table phase.
+ *
+ * @param writeDisposition - an instance of {@link WriteDisposition}.
+ */
+ public Write<T> withWriteDisposition(WriteDisposition writeDisposition) {
+ return toBuilder().setWriteDisposition(writeDisposition).build();
+ }
+
+ /**
+ * A snowflake service which is supposed to be used. Note: Currently we
have {@link
+ * SnowflakeServiceImpl} with corresponding {@link
FakeSnowflakeServiceImpl} used for testing.
+ *
+ * @param snowflakeService - an instance of {@link SnowflakeService}.
+ */
+ public Write<T> withSnowflakeService(SnowflakeService snowflakeService) {
+ return toBuilder().setSnowflakeService(snowflakeService).build();
+ }
+
+ @Override
+ public PDone expand(PCollection<T> input) {
+ checkArguments();
+
+ String stagingBucketDir = String.format("%s/%s/",
getStagingBucketName(), WRITE_TMP_PATH);
+
+ PCollection<String> out = write(input, stagingBucketDir);
+ out.setCoder(StringUtf8Coder.of());
+
+ return PDone.in(out.getPipeline());
+ }
+
+ private void checkArguments() {
+ checkArgument(getStagingBucketName() != null, "withStagingBucketName is
required");
+
+ checkArgument(getUserDataMapper() != null, "withUserDataMapper() is
required");
+
+ checkArgument(
+ (getDataSourceProviderFn() != null),
+ "withDataSourceConfiguration() or withDataSourceProviderFn() is
required");
+
+ checkArgument(getTable() != null, "withTable() is required");
+ }
+
+ private PCollection<String> write(PCollection<T> input, String
stagingBucketDir) {
+ SnowflakeService snowflakeService =
+ getSnowflakeService() != null ? getSnowflakeService() : new
SnowflakeServiceImpl();
+
+ PCollection<String> files = writeFiles(input, stagingBucketDir);
+
+ // Combining PCollection of files as a side input into one list of files
+ ListCoder<String> coder = ListCoder.of(StringUtf8Coder.of());
+ files =
+ (PCollection)
+ files
+ .getPipeline()
+ .apply(
+ Reify.viewInGlobalWindow(
+ (PCollectionView) files.apply(View.asList()),
coder));
+
+ return (PCollection)
+ files.apply("Copy files to table", copyToTable(snowflakeService,
stagingBucketDir));
+ }
+
+ private PCollection<String> writeFiles(PCollection<T> input, String
stagingBucketDir) {
+
+ PCollection<String> mappedUserData =
+ input
+ .apply(
+ MapElements.via(
+ new SimpleFunction<T, Object[]>() {
+ @Override
+ public Object[] apply(T element) {
+ return getUserDataMapper().mapRow(element);
+ }
+ }))
+ .apply("Map Objects array to CSV lines", ParDo.of(new
MapObjectsArrayToCsvFn()))
+ .setCoder(StringUtf8Coder.of());
+
+ WriteFilesResult filesResult =
+ mappedUserData.apply(
+ "Write files to specified location",
+ FileIO.<String>write()
+ .via(TextIO.sink())
+ .to(stagingBucketDir)
+ .withPrefix(getFileNameTemplate())
+ .withSuffix(".csv")
+ .withCompression(Compression.GZIP));
+
+ return (PCollection)
+ filesResult
+ .getPerDestinationOutputFilenames()
+ .apply("Parse KV filenames to Strings", Values.<String>create());
+ }
+
+ private ParDo.SingleOutput<Object, Object> copyToTable(
+ SnowflakeService snowflakeService, String stagingBucketDir) {
+ return ParDo.of(
+ new CopyToTableFn<>(
+ getDataSourceProviderFn(),
+ getTable(),
+ getQuery(),
+ stagingBucketDir,
+ getStorageIntegrationName(),
+ getWriteDisposition(),
+ snowflakeService));
+ }
+ }
+
+ public static class Concatenate extends Combine.CombineFn<String,
List<String>, List<String>> {
+ @Override
+ public List<String> createAccumulator() {
+ return new ArrayList<>();
+ }
+
+ @Override
+ public List<String> addInput(List<String> mutableAccumulator, String
input) {
+ mutableAccumulator.add(String.format("'%s'", input));
+ return mutableAccumulator;
+ }
+
+ @Override
+ public List<String> mergeAccumulators(Iterable<List<String>> accumulators)
{
+ List<String> result = createAccumulator();
+ for (List<String> accumulator : accumulators) {
+ result.addAll(accumulator);
+ }
+ return result;
+ }
+
+ @Override
+ public List<String> extractOutput(List<String> accumulator) {
+ return accumulator;
+ }
+ }
+
+ /**
+ * Custom DoFn that maps {@link Object[]} into CSV line to be saved to
Snowflake.
+ *
+ * <p>Adds Snowflake-specific quotations around strings.
+ */
+ private static class MapObjectsArrayToCsvFn extends DoFn<Object[], String> {
+
+ @ProcessElement
+ public void processElement(ProcessContext context) {
+ List<Object> csvItems = new ArrayList<>();
+ for (Object o : context.element()) {
+ if (o instanceof String) {
+ String field = (String) o;
+ field = field.replace("'", "''");
+ field = quoteField(field);
+
+ csvItems.add(field);
+ } else {
+ csvItems.add(o);
+ }
+ }
+ context.output(Joiner.on(",").useForNull("").join(csvItems));
Review comment:
@RyanSkraba thanks for pointing this. We're going to add this concern to
our feature improvement list :)
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