/**
* Test a simple flush on a simple HDFS file.
*
* @throws IOException an exception might be thrown
*/
@Test
public void testSimpleFlush() throws IOException {
Configuration conf = new HdfsConfiguration();
if (simulatedStorage) {
conf.setBoolean(SimulatedFSDataset.CONFIG_PROPERTY_SIMULATED, true);
}
fileContents = AppendTestUtil.initBuffer(AppendTestUtil.FILE_SIZE);
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).build();
FileSystem fs = cluster.getFileSystem();
try {
// create a new file.
Path file1 = new Path("/simpleFlush.dat");
FSDataOutputStream stm = AppendTestUtil.createFile(fs, file1, 1);
System.out.println("Created file simpleFlush.dat");
// write to file
int mid = AppendTestUtil.FILE_SIZE / 2;
stm.write(fileContents, 0, mid);
stm.hflush();
System.out.println("Wrote and Flushed first part of file.");
// write the remainder of the file
stm.write(fileContents, mid, AppendTestUtil.FILE_SIZE - mid);
System.out.println("Written second part of file");
stm.hflush();
stm.hflush();
System.out.println("Wrote and Flushed second part of file.");
// verify that full blocks are sane
checkFile(fs, file1, 1);
stm.close();
System.out.println("Closed file.");
// verify that entire file is good
AppendTestUtil.checkFullFile(fs, file1, AppendTestUtil.FILE_SIZE, fileContents, "Read 2");
} catch (IOException e) {
System.out.println("Exception :" + e);
throw e;
} catch (Throwable e) {
System.out.println("Throwable :" + e);
e.printStackTrace();
throw new IOException("Throwable : " + e);
} finally {
fs.close();
cluster.shutdown();
}
}
/**
* Test that file data can be flushed.
*
* @throws IOException an exception might be thrown
*/
@Test
public void testComplexFlush() throws IOException {
Configuration conf = new HdfsConfiguration();
if (simulatedStorage) {
conf.setBoolean(SimulatedFSDataset.CONFIG_PROPERTY_SIMULATED, true);
}
fileContents = AppendTestUtil.initBuffer(AppendTestUtil.FILE_SIZE);
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).build();
FileSystem fs = cluster.getFileSystem();
try {
// create a new file.
Path file1 = new Path("/complexFlush.dat");
FSDataOutputStream stm = AppendTestUtil.createFile(fs, file1, 1);
System.out.println("Created file complexFlush.dat");
int start = 0;
for (start = 0; (start + 29) < AppendTestUtil.FILE_SIZE; ) {
stm.write(fileContents, start, 29);
stm.hflush();
start += 29;
}
stm.write(fileContents, start, AppendTestUtil.FILE_SIZE - start);
// verify that full blocks are sane
checkFile(fs, file1, 1);
stm.close();
// verify that entire file is good
AppendTestUtil.checkFullFile(fs, file1, AppendTestUtil.FILE_SIZE, fileContents, "Read 2");
} catch (IOException e) {
System.out.println("Exception :" + e);
throw e;
} catch (Throwable e) {
System.out.println("Throwable :" + e);
e.printStackTrace();
throw new IOException("Throwable : " + e);
} finally {
fs.close();
cluster.shutdown();
}
}
//
// writes to file but does not close it
//
private void writeFile(FSDataOutputStream stm) throws IOException {
byte[] buffer = AppendTestUtil.initBuffer(AppendTestUtil.FILE_SIZE);
stm.write(buffer);
}