org.rosuda.REngine.Rserve.protocol
Class RTalk

java.lang.Object
  org.rosuda.REngine.Rserve.protocol.RTalk

public class RTalk
extends java.lang.Object

This class encapsulates the QAP1 protocol used by Rserv. it is independent of the underying protocol(s), therefore RTalk can be used over any transport layer

The current implementation supports long (0.3+/0102) data format only up to 32-bit and only for incoming packets.

Version:

$Id: RTalk.java 3247 2010-01-26 11:40:59Z urbanek $

Field Summary

static int	CMD_assignSEXP
static int	CMD_attachSession
static int	CMD_closeFile
static int	CMD_createFile
static int	CMD_ctrlEval
static int	CMD_ctrlShutdown
static int	CMD_ctrlSource
static int	CMD_detachedVoidEval
static int	CMD_detachSession
static int	CMD_eval
static int	CMD_login
static int	CMD_openFile
static int	CMD_readFile
static int	CMD_removeFile
static int	CMD_setBufferSize
static int	CMD_setEncoding
static int	CMD_setSEXP
static int	CMD_shutdown
static int	CMD_voidEval
static int	CMD_writeFile
static int	DT_ARRAY
static int	DT_BYTESTREAM
static int	DT_CHAR
static int	DT_DOUBLE
static int	DT_INT
static int	DT_LARGE this is a flag saying that the contents is large (>0xfffff0) and hence uses 56-bit length field
static int	DT_SEXP
static int	DT_STRING
static int	ERR_access_denied
static int	ERR_auth_failed
static int	ERR_conn_broken
static int	ERR_ctrl_closed
static int	ERR_data_overflow
static int	ERR_detach_failed
static int	ERR_inv_cmd
static int	ERR_inv_par
static int	ERR_IOerror
static int	ERR_not_open
static int	ERR_object_too_big
static int	ERR_out_of_mem
static int	ERR_Rerror
static int	ERR_session_busy
static int	ERR_unknown_cmd
static int	ERR_unsupported_cmd

Constructor Summary

RTalk(java.io.InputStream sis, java.io.OutputStream sos)
constructor; parameters specify the streams

Method Summary

static int	getInt(byte[] buf, int o) converts bit-wise stored int in Intel-endian form into Java int
static int	getLen(byte[] buf, int o) converts bit-wise stored length from a header.
static long	getLong(byte[] buf, int o) converts bit-wise Intel-endian format into long
static byte[]	newHdr(int ty, int len) creates a new header according to the type and length of the parameter
RPacket	request(int cmd) sends a request with no attached parameters
RPacket	request(int cmd, byte[] cont) sends a request with attached parameters
RPacket	request(int cmd, byte[] prefix, byte[] cont, int offset, int len) sends a request with attached prefix and parameters.
RPacket	request(int cmd, int par) sends a request with one string parameter attached
RPacket	request(int cmd, java.lang.String par) sends a request with one string parameter attached
static int	setHdr(int ty, int len, byte[] buf, int o) writes cmd/resp/type byte + 3/7 bytes len into a byte buffer at specified offset.
static void	setInt(int v, byte[] buf, int o) writes bit-wise int to a byte buffer at specified position in Intel-endian form
static void	setLong(long l, byte[] buf, int o)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DT_INT

public static final int DT_INT

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DT_CHAR

public static final int DT_CHAR

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DT_DOUBLE

public static final int DT_DOUBLE

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DT_STRING

public static final int DT_STRING

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DT_BYTESTREAM

public static final int DT_BYTESTREAM

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DT_SEXP

public static final int DT_SEXP

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DT_ARRAY

public static final int DT_ARRAY

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DT_LARGE

public static final int DT_LARGE

this is a flag saying that the contents is large (>0xfffff0) and hence uses 56-bit length field

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CMD_login

public static final int CMD_login

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CMD_voidEval

public static final int CMD_voidEval

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CMD_eval

public static final int CMD_eval

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CMD_shutdown

public static final int CMD_shutdown

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CMD_openFile

public static final int CMD_openFile

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CMD_createFile

public static final int CMD_createFile

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CMD_closeFile

public static final int CMD_closeFile

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CMD_readFile

public static final int CMD_readFile

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CMD_writeFile

public static final int CMD_writeFile

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CMD_removeFile

public static final int CMD_removeFile

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CMD_setSEXP

public static final int CMD_setSEXP

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CMD_assignSEXP

public static final int CMD_assignSEXP

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CMD_setBufferSize

public static final int CMD_setBufferSize

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CMD_setEncoding

public static final int CMD_setEncoding

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CMD_detachSession

public static final int CMD_detachSession

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CMD_detachedVoidEval

public static final int CMD_detachedVoidEval

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CMD_attachSession

public static final int CMD_attachSession

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CMD_ctrlEval

public static final int CMD_ctrlEval

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CMD_ctrlSource

public static final int CMD_ctrlSource

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CMD_ctrlShutdown

public static final int CMD_ctrlShutdown

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ERR_auth_failed

public static final int ERR_auth_failed

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ERR_conn_broken

public static final int ERR_conn_broken

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ERR_inv_cmd

public static final int ERR_inv_cmd

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ERR_inv_par

public static final int ERR_inv_par

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ERR_Rerror

public static final int ERR_Rerror

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ERR_IOerror

public static final int ERR_IOerror

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ERR_not_open

public static final int ERR_not_open

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ERR_access_denied

public static final int ERR_access_denied

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ERR_unsupported_cmd

public static final int ERR_unsupported_cmd

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ERR_unknown_cmd

public static final int ERR_unknown_cmd

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ERR_data_overflow

public static final int ERR_data_overflow

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ERR_object_too_big

public static final int ERR_object_too_big

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ERR_out_of_mem

public static final int ERR_out_of_mem

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ERR_ctrl_closed

public static final int ERR_ctrl_closed

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ERR_session_busy

public static final int ERR_session_busy

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ERR_detach_failed

public static final int ERR_detach_failed

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Constructor Detail

RTalk

public RTalk(java.io.InputStream sis,
             java.io.OutputStream sos)

constructor; parameters specify the streams

Parameters:

sis - socket input stream

sos - socket output stream

Method Detail

setInt

public static void setInt(int v,
                          byte[] buf,
                          int o)

writes bit-wise int to a byte buffer at specified position in Intel-endian form

Parameters:

v - value to be written

buf - buffer

o - offset in the buffer to start at. An int takes always 4 bytes

setHdr

public static int setHdr(int ty,
                         int len,
                         byte[] buf,
                         int o)

writes cmd/resp/type byte + 3/7 bytes len into a byte buffer at specified offset.

Parameters:

ty - type/cmd/resp byte

len - length

buf - buffer

o - offset

Returns:

offset in buf just after the header. Please note that since Rserve 0.3 the header can be either 4 or 8 bytes long, depending on the len parameter.

newHdr

public static byte[] newHdr(int ty,
                            int len)

creates a new header according to the type and length of the parameter

Parameters:

ty - type/cmd/resp byte

len - length

getInt

public static int getInt(byte[] buf,
                         int o)

converts bit-wise stored int in Intel-endian form into Java int

Parameters:

buf - buffer containg the representation

o - offset where to start (4 bytes will be used)

Returns:

the int value. no bounds checking is done so you need to make sure that the buffer is big enough

getLen

public static int getLen(byte[] buf,
                         int o)

converts bit-wise stored length from a header. "long" format is supported up to 32-bit

Parameters:

buf - buffer

o - offset of the header (length is at o+1)

Returns:

length

getLong

public static long getLong(byte[] buf,
                           int o)

converts bit-wise Intel-endian format into long

Parameters:

buf - buffer

o - offset (8 bytes will be used)

Returns:

long value

setLong

public static void setLong(long l,
                           byte[] buf,
                           int o)

request

public RPacket request(int cmd)

sends a request with no attached parameters

Parameters:

cmd - command

Returns:

returned packet or null if something went wrong

request

public RPacket request(int cmd,
                       byte[] cont)

sends a request with attached parameters

Parameters:

cmd - command

cont - contents - parameters

Returns:

returned packet or null if something went wrong

request

public RPacket request(int cmd,
                       byte[] prefix,
                       byte[] cont,
                       int offset,
                       int len)

sends a request with attached prefix and parameters. Both prefix and cont can be null. Effectively request(a,b,null) and request(a,null,b) are equivalent.

Parameters:

cmd - command - a special command of -1 prevents request from sending anything

prefix - - this content is sent *before* cont. It is provided to save memory copy operations where a small header precedes a large data chunk (usually prefix conatins the parameter header and cont contains the actual data).

cont - contents

offset - offset in cont where to start sending (if <0 then 0 is assumed, if >cont.length then no cont is sent)

len - number of bytes in cont to send (it is clipped to the length of cont if necessary)

Returns:

returned packet or null if something went wrong

request

public RPacket request(int cmd,
                       java.lang.String par)

sends a request with one string parameter attached

Parameters:

cmd - command

par - parameter - length and DT_STRING will be prepended

Returns:

returned packet or null if something went wrong

request

public RPacket request(int cmd,
                       int par)

sends a request with one string parameter attached

Parameters:

cmd - command

par - parameter of the type DT_INT

Returns:

returned packet or null if something went wrong