GH-3141: Add constructor to ParquetFileReader to pass parquet footer and expose setRequestedSchema that accepts List<ColumnDescriptor> (#3262)

Author: pan3793

parquet-hadoop/src/main/java/org/apache/parquet/hadoop/ParquetFileReader.java

@@ -567,8 +567,23 @@ public static final ParquetMetadata readFooter(InputFile file, MetadataFilter fi
 
   public static final ParquetMetadata readFooter(InputFile file, ParquetReadOptions options, SeekableInputStream f)
       throws IOException {
+    return readFooter(file, options, f, /*closeStreamOnFailure*/ false);
+  }
+
+  private static final ParquetMetadata readFooter(
+      InputFile file, ParquetReadOptions options, SeekableInputStream f, boolean closeStreamOnFailure)
+      throws IOException {
     ParquetMetadataConverter converter = new ParquetMetadataConverter(options);
-    return readFooter(file, options, f, converter);
+    try {
+      return readFooter(file, options, f, converter);
+    } catch (Exception e) {
+      // In case that readFooter throws an exception in the constructor, the new stream
+      // should be closed. Otherwise, there's no way to close this outside.
+      if (closeStreamOnFailure) {
+        f.close();
+      }
+      throw e;
+    }
   }
 
   private static final ParquetMetadata readFooter(
@@ -729,6 +744,22 @@ public static ParquetFileReader open(InputFile file, ParquetReadOptions options,
     return new ParquetFileReader(file, options, f);
   }
 
+  /**
+   * Open a {@link InputFile file} with {@link ParquetMetadata footer} and {@link ParquetReadOptions options}.
+   *
+   * @param file    an input file
+   * @param footer  a {@link ParquetMetadata} footer already read from the file
+   * @param options parquet read options
+   * @param f       the input stream for the file
+   * @return an open ParquetFileReader
+   * @throws IOException if there is an error while opening the file
+   */
+  public static ParquetFileReader open(
+      InputFile file, ParquetMetadata footer, ParquetReadOptions options, SeekableInputStream f)
+      throws IOException {
+    return new ParquetFileReader(file, footer, options, f);
+  }
+
   protected SeekableInputStream f;
   private final InputFile file;
   private final ParquetReadOptions options;
@@ -930,19 +961,31 @@ public ParquetFileReader(InputFile file, ParquetReadOptions options) throws IOEx
     this(file, options, file.newStream());
   }
 
+  /**
+   * @param file    Path to a parquet file
+   * @param options {@link ParquetReadOptions}
+   * @param f       a {@link SeekableInputStream} for the parquet file
+   * @throws IOException if the file can not be opened
+   */
   public ParquetFileReader(InputFile file, ParquetReadOptions options, SeekableInputStream f) throws IOException {
+    this(file, readFooter(file, options, f, /*closeStreamOnFailure*/ true), options, f);
+  }
+
+  /**
+   * @param file    Path to a parquet file
+   * @param footer  a {@link ParquetMetadata} footer already read from the file
+   * @param options {@link ParquetReadOptions}
+   * @param f       a {@link SeekableInputStream} for the parquet file
+   * @throws IOException if the file can not be opened
+   */
+  public ParquetFileReader(InputFile file, ParquetMetadata footer, ParquetReadOptions options, SeekableInputStream f)
+      throws IOException {
     this.converter = new ParquetMetadataConverter(options);
     this.file = file;
     this.f = f;
     this.options = options;
-    try {
-      this.footer = readFooter(file, options, f, converter);
-    } catch (Exception e) {
-      // In case that reading footer throws an exception in the constructor, the new stream
-      // should be closed. Otherwise, there's no way to close this outside.
-      f.close();
-      throw e;
-    }
+    this.footer = footer;
+
     this.fileMetaData = footer.getFileMetaData();
     this.fileDecryptor = fileMetaData.getFileDecryptor(); // must be called before filterRowGroups!
     if (null != fileDecryptor && fileDecryptor.plaintextFile()) {
@@ -1054,13 +1097,17 @@ public List<BlockMetaData> getRowGroups() {
     return blocks;
   }
 
-  public void setRequestedSchema(MessageType projection) {
+  public void setRequestedSchema(List<ColumnDescriptor> columns) {
     paths.clear();
-    for (ColumnDescriptor col : projection.getColumns()) {
+    for (ColumnDescriptor col : columns) {
       paths.put(ColumnPath.get(col.getPath()), col);
     }
   }
 
+  public void setRequestedSchema(MessageType projection) {
+    setRequestedSchema(projection.getColumns());
+  }
+
   public void appendTo(ParquetFileWriter writer) throws IOException {
     writer.appendRowGroups(f, blocks, true);
   }

parquet-hadoop/src/test/java/org/apache/parquet/hadoop/TestDataPageChecksums.java

@@ -36,6 +36,8 @@
 import java.util.zip.CRC32;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.Path;
+import org.apache.parquet.HadoopReadOptions;
+import org.apache.parquet.ParquetReadOptions;
 import org.apache.parquet.bytes.BytesInput;
 import org.apache.parquet.bytes.HeapByteBufferAllocator;
 import org.apache.parquet.bytes.TrackingByteBufferAllocator;
@@ -688,8 +690,13 @@ private int getDataOffset(Page page) {
    */
   private ParquetFileReader getParquetFileReader(Path path, Configuration conf, List<ColumnDescriptor> columns)
       throws IOException {
-    ParquetMetadata footer = ParquetFileReader.readFooter(conf, path);
-    return new ParquetFileReader(conf, footer.getFileMetaData(), path, footer.getBlocks(), columns);
+    HadoopInputFile inputFile = HadoopInputFile.fromPath(path, conf);
+    SeekableInputStream inputStream = inputFile.newStream();
+    ParquetReadOptions readOptions = HadoopReadOptions.builder(conf).build();
+    ParquetMetadata footer = ParquetFileReader.readFooter(inputFile, readOptions, inputStream);
+    ParquetFileReader reader = ParquetFileReader.open(inputFile, footer, readOptions, inputStream);
+    reader.setRequestedSchema(columns);
+    return reader;
   }
 
   /**