private void ReadProc()
{
var lengthBuffer = new byte[4];
var dataBuffer = new byte[m_mmf.Length - 4];
while (true)
{
// use a timeout so if the app ends, this thread can exit
if (!m_dataReady.WaitOne(1000, false))
{
continue;
}
// avoid receiving our own data
if (Sending)
{
// wait long enough for the sender to reset the m_dataReady flag
Thread2.Sleep(5);
continue;
}
// grab the mutex to prevent concurrency issues
m_mutex.WaitOne(1000, false);
// read from the start
m_mmf.Seek(0, System.IO.SeekOrigin.Begin);
// get the length
m_mmf.Read(lengthBuffer, 0, 4);
var length = BitConverter.ToInt32(lengthBuffer, 0);
// get the data
m_mmf.Read(dataBuffer, 0, length);
// release the mutex so any other clients can receive
m_mutex.ReleaseMutex();
// convert to a string
var received = Encoding.ASCII.GetString(dataBuffer, 0, length);
Console.WriteLine("Received: " + received);
Debug.WriteLine("Received: " + received);
}
}
public void TestInMemoryReadPositive()
{
MemoryMappedFile mmf = MemoryMappedFile.CreateInMemoryMap();
Assert.IsNotNull(mmf);
byte[] data = new byte[10];
long oldpos = mmf.Position;
mmf.Read(data, 0, data.Length);
Assert.AreEqual(oldpos + data.Length, mmf.Position, "Read caused incorrect movement in position");
}
public void TestBasicReadWritePositive()
{
MemoryMappedFile mmf = MemoryMappedFile.CreateInMemoryMap();
Assert.IsNotNull(mmf);
string sourceString = "This is some test data";
byte[] outdata = Encoding.ASCII.GetBytes(sourceString);
mmf.Write(outdata, 0, outdata.Length);
mmf.Seek(-outdata.Length, SeekOrigin.Current);
byte[] indata = new byte[outdata.Length];
mmf.Read(indata, 0, indata.Length);
string targetString = Encoding.ASCII.GetString(indata, 0, indata.Length);
Assert.AreEqual(sourceString, targetString);
}
public void TestReadPastEnd()
{
MemoryMappedFile mmf = MemoryMappedFile.CreateInMemoryMap();
Assert.IsNotNull(mmf);
EndOfStreamException expected = null;
mmf.Position = MemoryMappedFile.DefaultInMemoryMapSize - 5;
byte[] buffer = new byte[10];
try
{
mmf.Read(buffer, 0, buffer.Length);
}
catch (EndOfStreamException ex)
{
expected = ex;
}
Assert.IsNotNull(expected);
}
public void TestReadBeforeStart()
{
MemoryMappedFile mmf = MemoryMappedFile.CreateInMemoryMap();
Assert.IsNotNull(mmf);
ArgumentOutOfRangeException expected = null;
mmf.Position = 0;
byte[] buffer = new byte[10];
try
{
mmf.Read(buffer, -1, buffer.Length);
}
catch (ArgumentOutOfRangeException ex)
{
expected = ex;
}
Assert.IsNotNull(expected);
}
public static string readMemFile()
{
m_mmf = MemoryMappedFile.CreateInMemoryMap(SharedMapName, MaxMapSize);
// grab the mutex to prevent concurrency issues
if (!m_mutex.WaitOne(1000, false))
{
Debug.WriteLine("Unable to acquire mutex. read Abandoned");
return "@ERROR";
}
// read from the start
m_mmf.Seek(0, System.IO.SeekOrigin.Begin);
// get the length
m_mmf.Read(dataBuffer, 0, MaxMapSize);
int i;
for (i = 0; i < MaxMapSize; ++i)
{
if (dataBuffer[i] == 0)
{
if ((dataBuffer[i + 1] | dataBuffer[i + 2] | dataBuffer[i + 3] |
dataBuffer[i + 4] | dataBuffer[i + 5] | dataBuffer[i + 6] | dataBuffer[i + 7]) == 0)
break;
}
}
string received = Encoding.UTF8.GetString(dataBuffer, 0, i);
// release the mutex so any other clients can receive
m_mutex.ReleaseMutex();
Debug.WriteLine("Received: " + received);
return received;
}
byte[] ReadFileBytes(long Position, long Size)
{
if (FileBytes != null)
{
return(FileBytes.SubArray(Position, Size));
}
#if USE_MEMORY_MAPPED_FILE
var Data = new byte[Size];
// gr: [on OSX at least] you can read past the file size, (but within capacity)
// this doesn't error, but does fill the bytes with zeros.
var BytesRead = FileView.ReadArray(Position, Data, 0, (int)Size);
if (BytesRead != Size)
{
throw new System.Exception("Memory mapped file only read " + BytesRead + "/" + Size + " bytes");
}
return(Data);
#elif USE_FILE_HANDLE
var Data = new byte[Size];
var NewPos = File.Seek(Position, System.IO.SeekOrigin.Begin);
if (NewPos != Position)
{
throw new System.Exception("Seeked to " + Position + " but stream is at " + NewPos);
}
var BytesRead = File.Read(Data, 0, (int)Size);
if (BytesRead != Size)
{
throw new System.Exception("FileStream only read " + BytesRead + "/" + Size + " bytes");
}
return(Data);
#elif USE_JAVA_FILEHANDLE
return(File.ReadBytes(Position, Size));
#else
return(FileBytes.SubArray(Position, Size));
#endif
}