Jawin Instruction String Reference (in progress)

Important: Please note that the information in this document is from before the transition from com.develop.jawin to org.jawin in early 2003. Therefore this document may contain obsolete or incorrect information. Please also consult the instructions.h file.

Note: All instructions use little-endian byte ordering

List of instruction codes

Use cases

1. [in] long parameters
   
//Sample C API
__declspec (dllexport) bool WINAPI SendMeATen(long l) {
return (l == 10);
}

//Implementing a Java stub for the C API
static public void SendMeATen(int n) throws IOException, COMException {
FuncPtr fp = new FuncPtr("bin\\CallCOMUnitTestD.DLL", "SendMeATen");
NakedByteStream nbs = new NakedByteStream();
LittleEndianOutputStream leos = new LittleEndianOutputStream(nbs);
leos.writeInt(n);
GenericStub.win32Invoke(fp.getPeer(),"I:T1:", 4, 4, nbs.getInternalBuffer(), null);
}

//Calling the Java stub
InstructionTests.SendMeATen(10);


Use cases

1. [out] long* parameters
   
//Sample C API
__declspec (dllexport) void WINAPI FillInWithEleven(long* pl) {
*pl = 11;
}

//Implementing a Java stub for the C API
static public int FillInWithEleven() throws IOException, COMException {
FuncPtr fp = new FuncPtr("bin\\CallCOMUnitTestD.DLL", "FillInWithEleven");
byte[] result = GenericStub.win32Invoke(fp.getPeer(),"A::n4", 4, 0, null, null);
return StructConverter.bytesIntoInt(result, 0);
}

//Calling the Java stub
int eleven = InstructionTests.FillInWithEleven();
TestAssert.isTrue(eleven == 11);


Use cases

1. skipping past input params that take 0 default in Win32 APIs
   
//Sample C API
__declspec (dllexport) long WINAPI SkipDefaultedArg(long skip, long check) {
return check;
}

//Implementing a Java stub for the C API
static public int SkipDefaultedArg(int n) throws IOException, COMException {
FuncPtr fp = new FuncPtr("bin\\CallCOMUnitTestD.DLL", "SkipDefaultedArg");
NakedByteStream nbs = new NakedByteStream();
LittleEndianOutputStream leos = new LittleEndianOutputStream(nbs);
leos.writeInt(n);
byte[] result = GenericStub.win32Invoke(fp.getPeer(),"kI:I:", 8, 4, nbs.getInternalBuffer(), null);
return StructConverter.bytesIntoInt(result, 0);
}

//Calling the Java stub
int twelve = InstructionTests.SkipDefaultedArg(12);
TestAssert.isTrue(twelve == 12);


Use cases

1. passing in Unicode strings
   
//Sample C API
__declspec (dllexport) long WINAPI GetStringLength(BSTR bs) {
return wcslen(bs);
}

//Implementing a Java stub for the C API
static public int GetStringLength(String s) throws IOException, COMException {
FuncPtr fp = new FuncPtr("bin\\CallCOMUnitTestD.DLL", "GetStringLength");
NakedByteStream nbs = new NakedByteStream();
LittleEndianOutputStream leos = new LittleEndianOutputStream(nbs);
leos.writeStringUnicode(s);
byte[] result = GenericStub.win32Invoke(fp.getPeer(),"G:I:", 4, leos.size(), nbs.getInternalBuffer(), null);
return StructConverter.bytesIntoInt(result, 0);
}

//Calling the Java stub
int five = InstructionTests.GetStringLength("hello");
TestAssert.isTrue(five == 5);


Use cases

1. passing in structs, arrays
   
//Sample C API
__declspec (dllexport) long WINAPI GetNthByte(byte* b, long n) {
return (b[n]);
}

//Implementing a Java stub for the C API
static public int GetNthByte(byte[] b, int n) throws IOException, COMException {
FuncPtr fp = new FuncPtr("bin\\CallCOMUnitTestD.DLL", "GetNthByte");
NakedByteStream nbs = new NakedByteStream();
LittleEndianOutputStream leos = new LittleEndianOutputStream(nbs);
for (int loop=0; loop<b.length; loop++) {
leos.writeByte(b[loop]);
}
leos.writeInt(n);
String marshal = "P" + b.length + "I:I:";
byte[] result = GenericStub.win32Invoke(fp.getPeer(),marshal, 8, leos.size(), nbs.getInternalBuffer(), null);
return StructConverter.bytesIntoInt(result, 0);
}

//Calling the Java stub
byte[] bytes = {2,3,5,7,11};
int three = InstructionTests.GetNthByte(bytes, 1);
TestAssert.isTrue(three == 3);


Use cases

1. skipping unused arguments, going back to pick up arg
   
//Sample C API
__declspec (dllexport) void WINAPI FillOneTwoThree(long* one, long* two, long* three) {
*one = 1;
*two = 2;
*three = 3;
}

//Implementing a Java stub for the C API
static public void FillOneTwoThree() throws IOException, COMException {
FuncPtr fp = new FuncPtr("bin\\CallCOMUnitTestD.DLL", "FillOneTwoThree");
//extract second arg, then back up and extract first
byte[] result = GenericStub.win32Invoke(fp.getPeer(),"AAA::L4n4L-8n4", 12, 0, null, null);
//verify extractions
int two = StructConverter.bytesIntoInt(result, 0);
int one = StructConverter.bytesIntoInt(result, 4);
TestAssert.isTrue(two == 2);
TestAssert.isTrue(one == 1);
}

//Calling the Java stub
InstructionTests.FillOneTwoThree();


Use cases

1. arrays of complex types
   
//Sample C API
__declspec (dllexport) void WINAPI OneFishTwoFish(VARIANT* fill) {
fill[0].vt = VT_I4;
fill[0].iVal = 1;
fill[1].vt = VT_BSTR;
fill[1].bstrVal = ::SysAllocString(L"fish");
fill[2].vt = VT_I4;
fill[2].iVal = 2;
fill[3].vt = VT_BSTR;
fill[3].bstrVal = ::SysAllocString(L"fish");
}

//Implementing a Java stub for the C API
static public Object[] OneFishTwoFish() throws IOException, COMException {
FuncPtr fp = new FuncPtr("bin\\CallCOMUnitTestD.DLL", "OneFishTwoFish");
//extract second arg, then back up and extract first
int size = Variant.SIZEOF * 4;
String marshal = "M" + size + "::O|r4V!|";
byte[] result = GenericStub.win32Invoke(fp.getPeer(),marshal, 4, 0, null, null);
LittleEndianInputStream leis = new LittleEndianInputStream(new ByteArrayInputStream(result));
Object[] ret = new Object[4];
for (int n=0; n<4; n++) {
ret[n] = Variant.marshalOut(leis);
}
return ret;
}

//Calling the Java stub
Object[] oftf = InstructionTests.OneFishTwoFish();
TestAssert.isTrue(new Integer(1).equals(oftf[0]));
TestAssert.isTrue("fish".equals(oftf[1]));
TestAssert.isTrue(new Integer(2).equals(oftf[2]));
TestAssert.isTrue("fish".equals(oftf[3]));


Copyright (c) 2000-2005, The Jawin Project - LICENSE
This documentation was written for version: 1.0.19 of Jawin.
$Id: instruction_docs.html,v 1.6 2005/03/23 20:38:11 arosii_moa Exp $