Java Reader类代码示例

import org.apache.hadoop.io.file.tfile.TFile.Reader; //导入依赖的package包/类
void unsortedWithSomeCodec(String codec) throws IOException {
  Path uTfile = new Path(ROOT, "unsorted.tfile");
  FSDataOutputStream fout = createFSOutput(uTfile);
  Writer writer = new Writer(fout, minBlockSize, codec, null, conf);
  writeRecords(writer);
  writer.close();
  fout.close();
  FSDataInputStream fin = fs.open(uTfile);
  Reader reader =
      new Reader(fs.open(uTfile), fs.getFileStatus(uTfile).getLen(), conf);

  Scanner scanner = reader.createScanner();
  readAllRecords(scanner);
  scanner.close();
  reader.close();
  fin.close();
  fs.delete(uTfile, true);
}
 

import org.apache.hadoop.io.file.tfile.TFile.Reader; //导入依赖的package包/类
@Test
public void testFailureNegativeOffset() throws IOException {
  if (skip)
    return;
  writeRecords(2, true, true);

  Reader reader = new Reader(fs.open(path), fs.getFileStatus(path).getLen(), conf);
  Scanner scanner = reader.createScanner();
  byte[] buf = new byte[K];
  try {
    scanner.entry().getKey(buf, -1);
    fail("Failed to handle key negative offset.");
  }
  catch (Exception e) {
    // noop, expecting exceptions
  }
  finally {
  }
  scanner.close();
  reader.close();
}
 

import org.apache.hadoop.io.file.tfile.TFile.Reader; //导入依赖的package包/类
@Test
public void testFailureGetNonExistentMetaBlock() throws IOException {
  if (skip)
    return;
  writer.append("keyX".getBytes(), "valueX".getBytes());

  // create a new metablock
  DataOutputStream outMeta =
      writer.prepareMetaBlock("testX", Compression.Algorithm.GZ.getName());
  outMeta.write(123);
  outMeta.write("foo".getBytes());
  outMeta.close();
  closeOutput();

  Reader reader = new Reader(fs.open(path), fs.getFileStatus(path).getLen(), conf);
  DataInputStream mb = reader.getMetaBlock("testX");
  Assert.assertNotNull(mb);
  mb.close();
  try {
    DataInputStream mbBad = reader.getMetaBlock("testY");
    Assert.fail("Error on handling non-existent metablocks.");
  } catch (Exception e) {
    // noop, expecting exceptions
  }
  reader.close();
}
 

import org.apache.hadoop.io.file.tfile.TFile.Reader; //导入依赖的package包/类
@Test
public void testFailureReadValueManyTimes() throws IOException {
  if (skip)
    return;
  writeRecords(5);

  Reader reader = new Reader(fs.open(path), fs.getFileStatus(path).getLen(), conf);
  Scanner scanner = reader.createScanner();

  byte[] vbuf = new byte[BUF_SIZE];
  int vlen = scanner.entry().getValueLength();
  scanner.entry().getValue(vbuf);
  Assert.assertEquals(new String(vbuf, 0, vlen), VALUE + 0);
  try {
    scanner.entry().getValue(vbuf);
    Assert.fail("Cannot get the value mlutiple times.");
  } catch (Exception e) {
    // noop, expecting exceptions
  }

  scanner.close();
  reader.close();
}
 

import org.apache.hadoop.io.file.tfile.TFile.Reader; //导入依赖的package包/类
@Test
public void testFailureOpenEmptyFile() throws IOException {
  if (skip)
    return;
  closeOutput();
  // create an absolutely empty file
  path = new Path(fs.getWorkingDirectory(), outputFile);
  out = fs.create(path);
  out.close();
  try {
    new Reader(fs.open(path), fs.getFileStatus(path).getLen(), conf);
    Assert.fail("Error on handling empty files.");
  } catch (EOFException e) {
    // noop, expecting exceptions
  }
}
 

import org.apache.hadoop.io.file.tfile.TFile.Reader; //导入依赖的package包/类
@Test
public void testFailureOpenRandomFile() throws IOException {
  if (skip)
    return;
  closeOutput();
  // create an random file
  path = new Path(fs.getWorkingDirectory(), outputFile);
  out = fs.create(path);
  Random rand = new Random();
  byte[] buf = new byte[K];
  // fill with > 1MB data
  for (int nx = 0; nx < K + 2; nx++) {
    rand.nextBytes(buf);
    out.write(buf);
  }
  out.close();
  try {
    new Reader(fs.open(path), fs.getFileStatus(path).getLen(), conf);
    Assert.fail("Error on handling random files.");
  } catch (IOException e) {
    // noop, expecting exceptions
  }
}
 

import org.apache.hadoop.io.file.tfile.TFile.Reader; //导入依赖的package包/类
@Test
public void testFailureNegativeOffset_2() throws IOException {
  if (skip)
    return;
  closeOutput();

  Reader reader = new Reader(fs.open(path), fs.getFileStatus(path).getLen(), conf);
  Scanner scanner = reader.createScanner();
  try {
    scanner.lowerBound("keyX".getBytes(), -1, 4);
    Assert.fail("Error on handling negative offset.");
  } catch (Exception e) {
    // noop, expecting exceptions
  } finally {
    reader.close();
    scanner.close();
  }
  closeOutput();
}
 

import org.apache.hadoop.io.file.tfile.TFile.Reader; //导入依赖的package包/类
@Test
public void testFailureNegativeLength_2() throws IOException {
  if (skip)
    return;
  closeOutput();

  Reader reader = new Reader(fs.open(path), fs.getFileStatus(path).getLen(), conf);
  Scanner scanner = reader.createScanner();
  try {
    scanner.lowerBound("keyX".getBytes(), 0, -1);
    Assert.fail("Error on handling negative length.");
  } catch (Exception e) {
    // noop, expecting exceptions
  } finally {
    scanner.close();
    reader.close();
  }
  closeOutput();
}
 

import org.apache.hadoop.io.file.tfile.TFile.Reader; //导入依赖的package包/类
private void readValueBeforeKey(int recordIndex)
    throws IOException {
  Reader reader =
      new Reader(fs.open(path), fs.getFileStatus(path).getLen(), conf);
  Scanner scanner =
      reader.createScannerByKey(composeSortedKey(KEY, recordIndex)
          .getBytes(), null);

  try {
    byte[] vbuf = new byte[BUF_SIZE];
    int vlen = scanner.entry().getValueLength();
    scanner.entry().getValue(vbuf);
    Assert.assertEquals(new String(vbuf, 0, vlen), VALUE + recordIndex);

    byte[] kbuf = new byte[BUF_SIZE];
    int klen = scanner.entry().getKeyLength();
    scanner.entry().getKey(kbuf);
    Assert.assertEquals(new String(kbuf, 0, klen), composeSortedKey(KEY,
        recordIndex));
  } finally {
    scanner.close();
    reader.close();
  }
}
 

import org.apache.hadoop.io.file.tfile.TFile.Reader; //导入依赖的package包/类
private void readValueWithoutKey(int recordIndex)
    throws IOException {
  Reader reader = new Reader(fs.open(path), fs.getFileStatus(path).getLen(), conf);

  Scanner scanner =
      reader.createScannerByKey(composeSortedKey(KEY, recordIndex)
          .getBytes(), null);

  byte[] vbuf1 = new byte[BUF_SIZE];
  int vlen1 = scanner.entry().getValueLength();
  scanner.entry().getValue(vbuf1);
  Assert.assertEquals(new String(vbuf1, 0, vlen1), VALUE + recordIndex);

  if (scanner.advance() && !scanner.atEnd()) {
    byte[] vbuf2 = new byte[BUF_SIZE];
    int vlen2 = scanner.entry().getValueLength();
    scanner.entry().getValue(vbuf2);
    Assert.assertEquals(new String(vbuf2, 0, vlen2), VALUE
        + (recordIndex + 1));
  }

  scanner.close();
  reader.close();
}
 

import org.apache.hadoop.io.file.tfile.TFile.Reader; //导入依赖的package包/类
@Test
public void testFailureScannerWithKeys() throws IOException {
  Reader reader =
      new Reader(fs.open(path), fs.getFileStatus(path).getLen(), conf);
  Assert.assertFalse(reader.isSorted());
  Assert.assertEquals((int) reader.getEntryCount(), 4);

  try {
    Scanner scanner =
        reader.createScannerByKey("aaa".getBytes(), "zzz".getBytes());
    Assert
        .fail("Failed to catch creating scanner with keys on unsorted file.");
  }
  catch (RuntimeException e) {
  }
  finally {
    reader.close();
  }
}
 

import org.apache.hadoop.io.file.tfile.TFile.Reader; //导入依赖的package包/类
public void testFailureNegativeOffset() throws IOException {
  if (skip)
    return;
  writeRecords(2, true, true);

  Reader reader = new Reader(fs.open(path), fs.getFileStatus(path).getLen(), conf);
  Scanner scanner = reader.createScanner();
  byte[] buf = new byte[K];
  try {
    scanner.entry().getKey(buf, -1);
    Assert.fail("Failed to handle key negative offset.");
  }
  catch (Exception e) {
    // noop, expecting exceptions
  }
  finally {
  }
  scanner.close();
  reader.close();
}
 

import org.apache.hadoop.io.file.tfile.TFile.Reader; //导入依赖的package包/类
public void testFailureScannerWithKeys() throws IOException {
  Reader reader =
      new Reader(fs.open(path), fs.getFileStatus(path).getLen(), conf);
  Assert.assertFalse(reader.isSorted());
  Assert.assertEquals((int) reader.getEntryCount(), 4);

  try {
    Scanner scanner =
        reader.createScannerByKey("aaa".getBytes(), "zzz".getBytes());
    Assert
        .fail("Failed to catch creating scanner with keys on unsorted file.");
  }
  catch (RuntimeException e) {
  }
  finally {
    reader.close();
  }
}