public FunctionRegistry(DrillConfig config) {
try {
Set<Class<? extends CallProvider>> providerClasses =
PathScanner.scanForImplementations(
CallProvider.class,
config.getStringList(CommonConstants.LOGICAL_FUNCTION_SCAN_PACKAGES));
Map<String, FunctionDefinition> funcs = new HashMap<String, FunctionDefinition>();
for (Class<? extends CallProvider> c : providerClasses) {
CallProvider p = c.newInstance();
FunctionDefinition[] defs = p.getFunctionDefintions();
for (FunctionDefinition d : defs) {
for (String rn : d.getRegisteredNames()) {
FunctionDefinition d2 = funcs.put(rn, d);
// logger.debug("Registering function {}", d);
if (d2 != null) {
throw new ExceptionInInitializerError(
String.format(
"Failure while registering functions. The function %s tried to register with the name %s but the function %s already registered with that name.",
d.getName(), rn, d2.getName()));
}
}
}
}
funcMap = funcs;
} catch (Exception e) {
throw new RuntimeException("Failure while setting up FunctionRegistry.", e);
}
}
