/**
* Compile a string into a function or SimpleVariable.
*
* <p>Called by {@link #compileString(String)} when that has detected "${".
*
* <p>Calls {@link CompoundVariable#getNamedFunction(String)} if it detects: '(' - start of
* parameter list '}' - end of function call
*
* @param reader points to input after the "${"
* @return the function or variable object (or a String)
*/
Object makeFunction(StringReader reader) throws InvalidVariableException {
char[] current = new char[1];
char previous = ' '; // TODO - why use space?
StringBuilder buffer = new StringBuilder();
Object function;
try {
while (reader.read(current) == 1) {
if (current[0] == '\\') {
if (reader.read(current) == 0) {
break;
}
previous = ' ';
buffer.append(current[0]);
continue;
} else if (current[0] == '(' && previous != ' ') {
String funcName = buffer.toString();
function = CompoundVariable.getNamedFunction(funcName);
if (function instanceof Function) {
((Function) function).setParameters(parseParams(reader));
if (reader.read(current) == 0 || current[0] != '}') {
reader.reset(); // set to start of string
char[] cb = new char[100];
reader.read(cb); // return deliberately ignored
throw new InvalidVariableException(
"Expected } after " + funcName + " function call in " + new String(cb));
}
if (function instanceof TestListener) {
StandardJMeterEngine.register((TestListener) function);
}
return function;
} else { // Function does not exist, so treat as per missing variable
buffer.append(current[0]);
}
continue;
} else if (current[0] == '}') { // variable, or function with no parameter list
function = CompoundVariable.getNamedFunction(buffer.toString());
if (function instanceof Function) { // ensure that setParameters() is called.
((Function) function).setParameters(new LinkedList<CompoundVariable>());
}
buffer.setLength(0);
return function;
} else {
buffer.append(current[0]);
previous = current[0];
}
}
} catch (IOException e) {
log.error("Error parsing function: " + buffer.toString(), e);
return null;
}
log.warn("Probably an invalid function string: " + buffer.toString());
return buffer.toString();
}
/**
* Compile a String into a list of parameters, each made into a CompoundVariable.
*
* <p>Parses strings of the following form:
*
* <ul>
* <li>text)
* <li>text,text)
* <li>
* </ul>
*
* @param reader a StringReader pointing to the current input location, just after "("
* @return a list of CompoundVariable elements
*/
LinkedList<CompoundVariable> parseParams(StringReader reader) throws InvalidVariableException {
LinkedList<CompoundVariable> result = new LinkedList<CompoundVariable>();
StringBuilder buffer = new StringBuilder();
char[] current = new char[1];
char previous = ' ';
int functionRecursion = 0;
int parenRecursion = 0;
try {
while (reader.read(current) == 1) {
if (current[0] == '\\') { // Process escaped characters
buffer.append(current[0]); // Store the \
if (reader.read(current) == 0) {
break; // end of buffer
}
previous = ' ';
buffer.append(current[0]); // store the following character
continue;
} else if (current[0] == ',' && functionRecursion == 0) {
CompoundVariable param = new CompoundVariable();
param.setParameters(buffer.toString());
buffer.setLength(0);
result.add(param);
} else if (current[0] == ')' && functionRecursion == 0 && parenRecursion == 0) {
// Detect functionName() so this does not generate empty string as the parameter
if (buffer.length() == 0 && result.isEmpty()) {
return result;
}
// Normal exit occurs here
CompoundVariable param = new CompoundVariable();
param.setParameters(buffer.toString());
buffer.setLength(0);
result.add(param);
return result;
} else if (current[0] == '{' && previous == '$') {
buffer.append(current[0]);
previous = current[0];
functionRecursion++;
} else if (current[0] == '}' && functionRecursion > 0) {
buffer.append(current[0]);
previous = current[0];
functionRecursion--;
} else if (current[0] == ')' && functionRecursion == 0 && parenRecursion > 0) {
buffer.append(current[0]);
previous = current[0];
parenRecursion--;
} else if (current[0] == '(' && functionRecursion == 0) {
buffer.append(current[0]);
previous = current[0];
parenRecursion++;
} else {
buffer.append(current[0]);
previous = current[0];
}
}
} catch (IOException e) { // Should not happen with StringReader
log.error("Error parsing function: " + buffer.toString(), e);
}
// Dropped out, i.e. did not find closing ')'
log.warn("Probably an invalid function string: " + buffer.toString());
CompoundVariable var = new CompoundVariable();
var.setParameters(buffer.toString());
result.add(var);
return result;
}