/// <exception cref="System.Exception"/>
public virtual void TestSeekAfterSetDropBehind()
{
// start a cluster
Log.Info("testSeekAfterSetDropBehind");
Configuration conf = new HdfsConfiguration();
MiniDFSCluster cluster = null;
string TestPath = "/test";
int TestPathLen = MaxTestFileLen;
try
{
cluster = new MiniDFSCluster.Builder(conf).NumDataNodes(1).Build();
cluster.WaitActive();
FileSystem fs = cluster.GetFileSystem();
CreateHdfsFile(fs, new Path(TestPath), TestPathLen, false);
// verify that we can seek after setDropBehind
FSDataInputStream fis = fs.Open(new Path(TestPath));
try
{
NUnit.Framework.Assert.IsTrue(fis.Read() != -1);
// create BlockReader
fis.SetDropBehind(false);
// clear BlockReader
fis.Seek(2);
}
finally
{
// seek
fis.Close();
}
}
finally
{
if (cluster != null)
{
cluster.Shutdown();
}
}
}
/// <exception cref="System.Exception"/>
internal static long ReadHdfsFile(FileSystem fs, Path p, long length, bool dropBehind
)
{
FSDataInputStream fis = null;
long totalRead = 0;
try
{
fis = fs.Open(p);
if (dropBehind != null)
{
fis.SetDropBehind(dropBehind);
}
byte[] buf = new byte[8196];
while (length > 0)
{
int amt = (length > buf.Length) ? buf.Length : (int)length;
int ret = fis.Read(buf, 0, amt);
if (ret == -1)
{
return(totalRead);
}
totalRead += ret;
length -= ret;
}
}
catch (IOException e)
{
Log.Error("ioexception", e);
}
finally
{
if (fis != null)
{
fis.Close();
}
}
throw new RuntimeException("unreachable");
}