*
NOTES for Sim coders --------------------------------------------------
*
* A string will only be resolved once, therefore a variable may only be substituted in
* a string once. No references to reference. :-)
*
* SET. Both name and value will be resolved. All variables preceded with a '!' will be
* set on the registered transport. It will *not* be removed from the transport when
* it falls out of scope!
* WAIT. This instruction will block the VM until the time expires.
* *
* -----------------------------------------------------------------------
*
* This VM expects the following environment variables to be set
* before the execute() method is called. If they aren't set, the defaults
* will be used.
*
*
* VAR | DESC | DEFAULT | * ------------------------------------------------------------------------ * $sname$ | Session name. Added to log | The Sim.name | * | entries | | * ** * @see autohit.vm.VM * @see autohit.Sim * * @author Erich P. Gatejen * @version 1.0 * Version History *
EPG - Initial - 5Jan99
* EPG - Ok, try again using new VM architecture. - 22Jan99
*
*/
public class SimVM extends VM {
// --- FINAL FIELDS ------------------------------------------------------
// --- FIELDS ------------------------------------------------------------
/**
* The Sim to execute.
*
* @see autohit.Sim
*/
private Sim mySim;
/**
* Last response. Verification instructions will reference THIS
* field.
*
* @see autohit.transport.Response
*/
private Response lResponse;
/**
* Session name. This will be appended to each logged line.
* * If a $sname$ environment var was set for this sim, it will be used. * Otherwise, the Sim.name will be used. */ private String sname; /** * The logging mechinism. * * @see autohit.utils.Log */ public Log myLog; /** * The transport mechinism. * * @see autohit.transport.Transport */ public Transport myTransport; /** * The verification mechinism. * * @see autohit.verify.Verify */ public Verify myVerify; // --- PUBLIC METHODS ---------------------------------------------------- /** * Constructor. Will create the Sim VM but will not start execution; use the * start() method for that. *
* This class assumes that the logging object has already been started. *
* Do NOT use the default constructor! Call this constructor. * * @param theSim the Sim to be executed. * @param logTarget target for logging. * @param myTransport transport mechanism to use. This is for future use; you * can pass null to it. * @param myVerify verification mechanism. */ public SimVM(Sim theSim, Log logTarget, Transport theTransport, Verify theVerify ) { super(); mySim = theSim; myLog = logTarget; myTransport = theTransport; myVerify = theVerify; } /** * Prepare for execution of the first instruction. We need to * add environment variables. DO NOT call this method directly. * * @throws Any exceptions it encounters. */ public void prepare() throws Exception { // Check for default environment variables if (vars.containsKey("sname")) { sname = (String)vars.get("sname"); } else { vars.put("sname", mySim.name); sname = mySim.name; } // Set stock environment vars vars.put("lastVerify", "0"); vars.put("transCode", "0"); } /** * Implements the inherited abstract method execute(). Call this to execute * a single instruction, The first call will be automatic after the inherited * start() method is called. From there, the owning Object/Thread should * call this method for each successive instruction to execute. *
* This method will throw a VMException(VMException.DONE) if there are * no more instructions that can be executed. (The ip is past the * end of the exec Vector). *
* We shall assume that a VMContext will handle * threading issues. * @see autohit.vm.VMContext * @throws VMException * @see autohit.vm.VMException */ public void execute() throws VMException { // Any instructions left to execute? if (ip >= mySim.exec.size()) { throw new VMException(VMException.DONE); } try { VMInstruction ci = (VMInstruction)mySim.exec.get(ip); // NOTES: Each instruction is responsible for advancing the // ip. //DEBUG //System.out.println("IP = " + ip + " token=" + ci.nToken); switch(ci.nToken) { case VMInstruction.NOP: // Just burn the cycle ip++; break; case VMInstruction.GET: handleGet((VMIGet)ci); ip++; break; case VMInstruction.FOR: handleFor((VMIFor)ci); break; case VMInstruction.WHILE: handleWhile((VMIWhile)ci); break; case VMInstruction.SET: handleSet((VMISet)ci); ip++; break; case VMInstruction.WAIT: handleWait((VMIWait)ci); ip++; break; case VMInstruction.SCOPE: // Just toss it on the scope stack pushScope(ci); ip++; break; case VMInstruction.RSCOPE: // Let the VM unravel the scope stack. discardScopeFrame(); ip++; break; case VMInstruction.HEADER: // Just toss it on the scope stack pushScope(ci); ip++; break; case VMInstruction.IF: handleIf((VMIIf)ci); break; case VMInstruction.NV: // Just toss it on the scope stack pushScope(ci); ip++; break; case VMInstruction.JUMP: // Change the instruction pointer to the target VMIJump vmij = (VMIJump)ci; ip = vmij.target; break; case VMInstruction.ADD: handleAdd((VMIAdd)ci); ip++; break; case VMInstruction.VERIFY: handleVerify((VMIVerify)ci); ip++; break; case VMInstruction.CRC: handleCrc((VMICrc)ci); ip++; break; case VMInstruction.SEEK: handleSeek((VMISeek)ci); ip++; break; case VMInstruction.EXEC: handleExec((VMIExec)ci); ip++; break; default: String em = new String("Software Detected Fault: Unsupported instruction encounted by autohit.SimVM. nToken=[" + ci.nToken + "]"); wfLogPut(em); throw new VMException(VMException.INVALID_INSTRUCTION, em); } } catch (VMException e) { wfLogPut("!FAULT! in SimVM. Exception #" + e.numeric); wfLogSub("message= " + e.getMessage()); throw e; } } // == =============================================================================== // == = INSTRUCTION HANDLERS = // == =============================================================================== private void handleSet(VMISet instr) throws VMException { String name = instr.name; String value = instr.value; // Resolve any variables. if (instr.iv) { name = subVar(name); value = subVar(value); } // If it isn't already in the vars, toss a reference on the scope stack. if (!vars.containsKey(name)) { pushScope(name); } vars.put(name, value); // Do we need to set it with the transport? if(name.charAt(0) == '!') { try { myTransport.environment(name.substring(1), value); } catch (Exception e) { throw new VMException(VMException.VARIABLE_TYPE_MISMATCH, "Empty transport environment variable"); } } } private void handleWait(VMIWait instr) throws VMException { String time = instr.time; int numeric = 0; // Resolve any variables. if (instr.iv) { time = subVar(time); } // try to get a number out of the time field try { numeric = Integer.parseInt(time); } catch (Exception e) { throw new VMException(VMException.VARIABLE_TYPE_MISMATCH , "Time is not a numeric. [" + time + "]"); } // Wait... try { wfLogPut("WAIT: start=" + ticks() + " for " + numeric); Thread.sleep(numeric); } catch (Exception e) { // dont care if we are interrupted. } } private void handleGet(VMIGet instr) throws VMException { int tstart = 0; int tlen = 0; try { Query q = buildQuery(); if (instr.iv) { q.qs = subVar(instr.qs); } else { q.qs = instr.qs; } tstart = this.ticks(); lResponse = myTransport.push(q); tlen = this.ticks() - tstart; wfLogPut("GET:" + "[s=" + tstart + " l=" + tlen + "] tcode=" + lResponse.code + " size=" + lResponse.cLength); wfLogSub("url=" + q.qs); vars.put("transCode", Integer.toString(lResponse.code)); } catch (Exception e) { // Prolly should come back and make this exception more informative.... wfLogPut("GET: Failed do to exception! for url="); wfLogSub(instr.qs); wfLogSub("Exception =" + e.getMessage()); } } private void handleIf(VMIIf instr) throws VMException { String e = instr.e; String value = instr.value; // Resolve any variables. if (instr.iv) { e = subVar(e); value = subVar(value); } // Are they equal? if (e.equals(value)) { // Yes. Advance IP to next instruction ip++; } else { // Nope. Jump over the block ip = instr.target; } } private void handleFor(VMIFor instr) throws VMException { String count = instr.count; // automatically resolve any variables. count = subVar(count); String value = (String)vars.get(count); // Are they equal? if (value.equals("0")) { // Yes. JJump to the target ip = instr.target; } else { // Nope. Next instruction ip++; } } private void handleWhile(VMIWhile instr) throws VMException { String e = instr.e; String value = instr.value; // Resolve any variables. if (instr.iv) { e = subVar(e); value = subVar(value); } // Are they equal? if (e.equals(value)) { // Yes. jump back and do the loop again ip = instr.target; } else { // Nope. move out of the block ip++; } } private void handleAdd(VMIAdd instr) throws VMException { String name = instr.name; String value = instr.value; int result = 0; // Resolve any variables. if (instr.iv) { name = subVar(name); value = subVar(value); } // Find the variable. String varVal = (String)vars.get(name); if (varVal == null) { throw new VMException(VMException.VARIABLE_NOT_DEFINED , "Variable not defined for ADD. [" + name + "]"); } // Try add them. try { result = Integer.parseInt(varVal) + Integer.parseInt(value); } catch (Exception e) { throw new VMException(VMException.VARIABLE_TYPE_MISMATCH , "Type mismatch in add. [" + varVal + "][" + value + "]"); } vars.put(name, String.valueOf(result)); } private void handleVerify(VMIVerify instr) throws VMException { try { // freshed the context myVerify.fresh(lResponse); // verify size if we must... if (instr.size != VMIVerify.NO_SIZE) { if (myVerify.size(instr.size)) { wfPass("SIZE."); } else { wfFail("SIZE. difference=" + myVerify.lastDelta()); } } } catch (Exception e) { throw new VMException(VMException.SUBSYSTEM_FAULT , "Verification Subsystem fault. Unable to freshen context. sub=" + e.getMessage()); } } private void handleCrc(VMICrc instr) throws VMException { try { if (myVerify.crc(instr.expected)) { wfPass("CRC."); } else { wfFail("CRC. difference=" + myVerify.lastDelta()); } } catch (Exception e) { throw new VMException(VMException.SUBSYSTEM_FAULT , "Verification Subsystem fault. Unable to verify CRC. sub=" + e.getMessage()); } } private void handleSeek(VMISeek instr) throws VMException { try { if (myVerify.seek(instr.expected)) { wfPass("SEEK."); } else { wfFail("SEEK. expected=" + instr.expected); } } catch (Exception e) { throw new VMException(VMException.SUBSYSTEM_FAULT , "Verification Subsystem fault. Unable to verify SEEK. sub=" + e.getMessage()); } } private void handleExec(VMIExec instr) throws VMException { try { if (myVerify.exec(instr.invocation, instr.content)) { wfPass("EXEC."); } else { wfFail("EXEC."); } } catch (Exception e) { throw new VMException(VMException.SUBSYSTEM_FAULT , "Verification Subsystem fault. Unable to verify EXEC. sub=" + e.getMessage()); } } // == =============================================================================== // == = PRIVATE METHODS = // == =============================================================================== private void wfLogPut(String text) { myLog.put(sname + ":" + text); } private void wfLogSub(String text) { myLog.putSub(sname + ":" + text); } private void wfPass(String text) { vars.put("lastVerify", "1"); myLog.putSub("PASS :" + text); } private void wfFail(String text) { vars.put("lastVerify", "0"); myLog.putSub("FAIL :" + text); } // Does the grunt work of looking throw the scope stack for headers and NVs private Query buildQuery() throws VMException { Vector h = new Vector(); Vector b = new Vector(); String name; String value; Object so; VMIHeader hobj; VMINV nobj; NVPair nv; Query q = new Query(); // Run the scope stack. int size = scope.size() - 1; while (size > 0) { so = scope.elementAt(size); if ( so instanceof VMIHeader) { hobj = (VMIHeader)so; name = subVar(hobj.name); value = subVar(hobj.value); nv = new NVPair(name, value); h.add(nv); } else if (so instanceof VMINV) { nobj = (VMINV)so; name = subVar(nobj.name); value = subVar(nobj.value); nv = new NVPair(name, value); b.add(nv); } size--; } // build the Query if (h.size() > 0) { q.headers = (HTTPClient.NVPair[]) h.toArray(new NVPair[h.size()]); } else { q.headers = null; } if (b.size() > 0) { q.body = (HTTPClient.NVPair[]) b.toArray(new NVPair[b.size()]); } else { q.body = null; } return q; } }