boyuanzz commented on a change in pull request #12223:
URL: https://github.com/apache/beam/pull/12223#discussion_r461796953
##########
File path:
sdks/java/io/parquet/src/main/java/org/apache/beam/sdk/io/parquet/ParquetIO.java
##########
@@ -235,12 +284,151 @@ public ReadFiles withAvroDataModel(GenericData model) {
return toBuilder().setAvroDataModel(model).build();
}
+ public ReadFiles withSplit() {
+ return toBuilder().setSplit(true).build();
+ }
+
@Override
public PCollection<GenericRecord> expand(PCollection<FileIO.ReadableFile>
input) {
checkNotNull(getSchema(), "Schema can not be null");
- return input
- .apply(ParDo.of(new ReadFn(getAvroDataModel())))
- .setCoder(AvroCoder.of(getSchema()));
+ if (getSplit() != null) {
+ return input
+ .apply(ParDo.of(new SplitReadFn(getAvroDataModel())))
+ .setCoder(AvroCoder.of(getSchema()));
+ } else {
+ return input
+ .apply(ParDo.of(new ReadFn(getAvroDataModel())))
+ .setCoder(AvroCoder.of(getSchema()));
+ }
+ }
+
+ @DoFn.BoundedPerElement
+ static class SplitReadFn extends DoFn<FileIO.ReadableFile, GenericRecord> {
+ private Class<? extends GenericData> modelClass;
+ private static final Logger LOG =
LoggerFactory.getLogger(SplitReadFn.class);
+ ReadSupport<GenericRecord> readSupport;
+
+ SplitReadFn(GenericData model) {
+ this.modelClass = model != null ? model.getClass() : null;
+ }
+
+ private static <K, V> Map<K, Set<V>> toSetMultiMap(Map<K, V> map) {
+ Map<K, Set<V>> setMultiMap = new HashMap<K, Set<V>>();
+ for (Map.Entry<K, V> entry : map.entrySet()) {
+ Set<V> set = new HashSet<V>();
+ set.add(entry.getValue());
+ setMultiMap.put(entry.getKey(), Collections.unmodifiableSet(set));
+ }
+ return Collections.unmodifiableMap(setMultiMap);
+ }
+
+ @ProcessElement
+ public void processElement(
+ @Element FileIO.ReadableFile file,
+ RestrictionTracker<OffsetRange, Long> tracker,
+ OutputReceiver<GenericRecord> outputReceiver)
+ throws Exception {
+ if (!file.getMetadata().isReadSeekEfficient()) {
+ ResourceId filename = file.getMetadata().resourceId();
+ throw new RuntimeException(String.format("File has to be seekable:
%s", filename));
+ }
+
+ SeekableByteChannel seekableByteChannel = file.openSeekable();
+ ReadSupport<GenericRecord> readSupport;
+ InputFile inputFile = new BeamParquetInputFile(seekableByteChannel);
+ Configuration conf = setConf();
+ GenericData model = null;
+ if (modelClass != null) {
+ model = (GenericData) modelClass.getMethod("get").invoke(null);
+ }
+ readSupport = new AvroReadSupport<GenericRecord>(model);
+ ParquetReadOptions options = HadoopReadOptions.builder(conf).build();
+ ParquetFileReader reader = ParquetFileReader.open(inputFile, options);
+ Filter filter = checkNotNull(options.getRecordFilter(), "filter");
+ conf = ((HadoopReadOptions) options).getConf();
+ for (String property : options.getPropertyNames()) {
+ conf.set(property, options.getProperty(property));
+ }
+ FileMetaData parquetFileMetadata =
reader.getFooter().getFileMetaData();
+ MessageType fileSchema = parquetFileMetadata.getSchema();
+ Map<String, String> fileMetadata =
parquetFileMetadata.getKeyValueMetaData();
+
+ ReadSupport.ReadContext readContext =
+ readSupport.init(new InitContext(conf,
toSetMultiMap(fileMetadata), fileSchema));
+ ColumnIOFactory columnIOFactory = new
ColumnIOFactory(parquetFileMetadata.getCreatedBy());
+ MessageType requestedSchema = readContext.getRequestedSchema();
+ RecordMaterializer<GenericRecord> recordConverter =
+ readSupport.prepareForRead(conf, fileMetadata, fileSchema,
readContext);
+ boolean strictTypeChecking = options.isEnabled(STRICT_TYPE_CHECKING,
true);
+ boolean filterRecords = options.useRecordFilter();
+ reader.setRequestedSchema(requestedSchema);
+ MessageColumnIO columnIO =
+ columnIOFactory.getColumnIO(requestedSchema, fileSchema,
strictTypeChecking);
+ for (int i = 0; i < reader.getRowGroups().size(); i++) {
+ if (i < tracker.currentRestriction().getFrom()) {
+ reader.skipNextRowGroup();
+ continue;
+ }
+ if (tracker.tryClaim((long) i)) {
+ PageReadStore pages = reader.readNextRowGroup();
+ i += 1;
+ RecordReader<GenericRecord> recordReader =
+ columnIO.getRecordReader(
+ pages, recordConverter, filterRecords ? filter :
FilterCompat.NOOP);
+ GenericRecord read;
+ long current = 0;
+ long totalRows = pages.getRowCount();
+ while (current < totalRows) {
+ read = recordReader.read();
+ outputReceiver.output(read);
+ current += 1;
+ }
+ } else {
+ break;
+ }
+ }
+ }
+
+ private Configuration setConf() throws Exception {
+ Configuration conf = new Configuration();
+ GenericData model = null;
+ if (modelClass != null) {
+ model = (GenericData) modelClass.getMethod("get").invoke(null);
+ }
+ if (model != null
+ && (model.getClass() == GenericData.class || model.getClass() ==
SpecificData.class)) {
+ conf.setBoolean(AvroReadSupport.AVRO_COMPATIBILITY, true);
+ } else {
+ conf.setBoolean(AvroReadSupport.AVRO_COMPATIBILITY, false);
+ }
+ return conf;
+ }
+
+ @GetInitialRestriction
+ public OffsetRange getInitialRestriction(@Element FileIO.ReadableFile
file) throws Exception {
+ if (!file.getMetadata().isReadSeekEfficient()) {
+ ResourceId filename = file.getMetadata().resourceId();
+ throw new RuntimeException(String.format("File has to be seekable:
%s", filename));
+ }
+ SeekableByteChannel seekableByteChannel = file.openSeekable();
+ InputFile inputFile = new BeamParquetInputFile(seekableByteChannel);
+ Configuration conf = setConf();
+ ParquetReadOptions options = HadoopReadOptions.builder(conf).build();
+ ParquetFileReader reader = ParquetFileReader.open(inputFile, options);
+ return new OffsetRange(0, reader.getRowGroups().size());
+ }
+
+ @SplitRestriction
+ public void split(@Restriction OffsetRange restriction,
OutputReceiver<OffsetRange> out) {
Review comment:
It seems like what Jiadai is trying to do is taking a file as element
and the number of row group as restriction. When SDF.process() is called, it
will read all row groups defined in the restriction for one file. If using
BlockBasedTracker, the restriction will be the number of blocks. I think the
key point here is to define what should be the element and restriction for this
source.
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