static FileHandle[] openFiles = new FileHandle[100]; // all file handles in use (0 will not be used at any time)
private static Primitive OpenWriteImpl(Primitive filename, bool append)
{
String f = (filename == null ? "" : filename.ToString());
if (!f.StartsWith("/"))
{
f = "/home/root/lms2012/prjs/" + f;
}
lock (openFiles)
{
if (findHandle(f) >= 0) // already have open file with this name
{
return(new Primitive(0));
}
int i = findUnusedHandleSlot();
if (i <= 0) // can not hold any more files
{
return(new Primitive(0));
}
// create a new empty file. must close handle immediately because it can not be kept accross direct commands
ByteCodeBuffer c = new ByteCodeBuffer();
c.OP(0xC0); // opFile
c.CONST(append ? 0x00: 0x02); // OPEN_APPEND = 0x00 OPEN_WRITE = 0x02
c.STRING(f);
c.GLOBVAR(0); // result: 16-bit handle
c.OP(0xC0); // opFile
c.CONST(0x07); // CLOSE = 0x07
c.GLOBVAR(0);
// check if could indeed create/append file on the brick
byte[] reply = EV3RemoteControler.DirectCommand(c, 2, 0);
if (reply == null || reply.Length < 2 || (reply[0] == 0 && reply[1] == 0))
{
return(new Primitive(0));
}
// memorize the open file
openFiles[i] = new FileHandle(f);
return(new Primitive((double)i));
}
}
/// <summary>
/// Read one byte of data from the file.
/// </summary>
/// <param name="handle">The file handle (previously obtained from an Open... call)</param>
/// <returns>The next byte from the file</returns>
public static Primitive ReadByte(Primitive handle)
{
int hdl = handle;
lock (openFiles)
{
if (hdl >= 0 && hdl < openFiles.Length && openFiles[hdl] != null)
{
FileHandle fh = openFiles[hdl];
if (fh.content != null && fh.readcursor < fh.content.Length)
{
byte b = fh.content[fh.readcursor];
fh.readcursor++;
return(new Primitive((int)b));
}
}
}
return(new Primitive(0));
}
/// <summary>
/// Open a file for reading data. When the file does not exist, a 0 is returned.
/// </summary>
/// <param name="filename">Name of the file to read from</param>
/// <returns>A number that identifies this open file (a.k.a. file handle) or 0 if file does not exist</returns>
public static Primitive OpenRead(Primitive filename)
{
String f = (filename == null ? "" : filename.ToString());
if (!f.StartsWith("/"))
{
f = "/home/root/lms2012/prjs/" + f;
}
lock (openFiles)
{
if (findHandle(f) >= 0) // already have open file with this name
{
return(new Primitive(0));
}
int i = findUnusedHandleSlot();
if (i <= 0) // can not hold any more files
{
return(new Primitive(0));
}
byte[] content = null;
try
{
content = EV3RemoteControler.ReadEV3File(f);
}
catch (Exception) { }
if (content == null)
{
return(new Primitive(0));
}
FileHandle fh = new FileHandle(f, content);
openFiles[i] = fh;
return(new Primitive((double)i));
}
}
/// <summary>
/// Read a whole array of numbers in binary form from the file. The numbers are encoded in IEEE single precision floating point representation.
/// </summary>
/// <param name="handle">The file handle (previously obtained from an Open... call)</param>
/// <param name="size">Number of values to read</param>
/// <returns>An array of size elements holding the values</returns>
public static Primitive ReadNumberArray(Primitive handle, Primitive size)
{
int hdl = handle;
int siz = size;
lock (openFiles)
{
if (hdl >= 0 && hdl < openFiles.Length && openFiles[hdl] != null && siz > 0)
{
FileHandle fh = openFiles[hdl];
if (fh.content != null && fh.readcursor + 4 * siz <= fh.content.Length)
{
double[] values = new double[siz];
for (int i = 0; i < siz; i++)
{
values[i] = BitConverter.ToSingle(fh.content, fh.readcursor + 4 * i);
}
fh.readcursor += 4 * siz;
return(A2P(values));
}
}
}
return(A2P(new double[0]));
}
/// <summary>
/// Read one line of text from the file. The line will be decoded using the ISO-8859-1 encoding and must be terminated with a newline-character (code 10).
/// </summary>
/// <param name="handle">The file handle (previously obtained from an Open... call)</param>
/// <returns>The text from the current line in the file</returns>
public static Primitive ReadLine(Primitive handle)
{
int hdl = handle;
lock (openFiles)
{
if (hdl >= 0 && hdl < openFiles.Length && openFiles[hdl] != null)
{
FileHandle fh = openFiles[hdl];
if (fh.content != null && fh.readcursor < fh.content.Length)
{
StringBuilder b = new StringBuilder();
while (fh.readcursor < fh.content.Length && fh.content[fh.readcursor] != '\n')
{
b.Append((char)fh.content[fh.readcursor]);
fh.readcursor++;
}
fh.readcursor++;
return(new Primitive(b.ToString()));
}
}
}
return(new Primitive(""));
}
