/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.pig;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.apache.pig.classification.InterfaceAudience;
import org.apache.pig.classification.InterfaceStability;
import org.apache.pig.impl.logicalLayer.schema.Schema;
/**
* Class to represent a UDF specification.
* Encapsulates the class name and the arguments to the constructor.
*/
@InterfaceAudience.Public
@InterfaceStability.Stable
public class FuncSpec implements Serializable, Cloneable {
private static final long serialVersionUID = 2L;
String className = null;
String[] ctorArgs = null;
Schema inputArgsSchema = null;
/**
* @param className the name of the class for the udf
* @param ctorArg the argument to pass the constructor for the above class.
* Constructors can only take strings.
*/
public FuncSpec(String className, String ctorArg) {
this.className = className;
this.ctorArgs = new String[1];
this.ctorArgs[0] = ctorArg;
}
/**
* @param className the name of the class for the udf
* @param ctorArgs the arguments to pass to the constructor for the above class.
* Constructors can only take strings.
*/
public FuncSpec(String className, String[] ctorArgs) {
this.className = className;
this.ctorArgs = ctorArgs;
}
/**
* @param className the name of the class for the udf
* @param ctorArgs the arguments to pass to the constructor for the above class.
* Constructors can only take strings.
* @param inputArgsSchema schema for input args taken by this Function
*/
public FuncSpec(String className, String[] ctorArgs, Schema inputArgsSchema) {
this(className, ctorArgs);
this.inputArgsSchema = inputArgsSchema;
}
/**
* @param funcSpec the name of the function and any arguments.
* It should have the form: classname('arg1', 'arg2', ...)
*/
public FuncSpec(String funcSpec) {
this.className = getClassNameFromSpec(funcSpec);
List<String> args = parseArguments(getArgStringFromSpec(funcSpec));
if(args.size() > 0) {
this.ctorArgs = new String[args.size()];
int i = 0;
for (Iterator<String> iterator = args.iterator(); iterator.hasNext();) {
this.ctorArgs[i++] = iterator.next();
}
}
}
/**
*
* @param funcSpec funcSpec the name of the function and any arguments.
* It should have the form: classname('arg1', 'arg2', ...)
* @param inputArgsSchema schema for input args taken by this Function
*/
public FuncSpec(String funcSpec, Schema inputArgsSchema) {
this(funcSpec);
this.inputArgsSchema = inputArgsSchema;
}
/**
* Parse the class name out of a function specification string.
* @return name of the class.
*/
public static String getClassNameFromSpec(String funcSpec){
int paren = funcSpec.indexOf('(');
if (paren!=-1)
return funcSpec.substring(0, paren);
else
return funcSpec;
}
/**
* Get the argument values passed to the func spec.
* @return argument values. Format will be arg1, arg2, ... )
*/
public static String getArgStringFromSpec(String funcSpec){
int paren = funcSpec.indexOf('(');
if (paren!=-1)
return funcSpec.substring(paren+1);
else
return "";
}
/**
* Parse the argument values out of a function specification string.
* @param argString should be of the form "'arg1', 'arg2', ..."
* @return List of the different argument strings
*/
public static List<String> parseArguments(String argString){
List<String> args = new ArrayList<String>();
int startIndex = 0;
int endIndex;
while (startIndex < argString.length()) {
while (startIndex < argString.length() && argString.charAt(startIndex++) != '\'')
;
endIndex = startIndex;
while (endIndex < argString.length() && argString.charAt(endIndex) != '\'') {
if (argString.charAt(endIndex) == '\\')
endIndex++;
endIndex++;
}
if (endIndex < argString.length()) {
args.add(argString.substring(startIndex, endIndex));
}
startIndex = endIndex + 1;
}
return args;
}
/**
* @return the className
*/
public String getClassName() {
return className;
}
/**
* @param className the className to set
*/
public void setClassName(String className) {
this.className = className;
}
/**
* @return the ctorArgs
*/
public String[] getCtorArgs() {
return ctorArgs;
}
/**
* @param ctorArgs the ctorArgs to set
*/
public void setCtorArgs(String[] ctorArgs) {
this.ctorArgs = ctorArgs;
}
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append(className);
if(ctorArgs != null) {
sb.append("(");
for (int i = 0; i < ctorArgs.length; i++) {
sb.append("'");
sb.append(ctorArgs[i]);
sb.append("'");
if(i != ctorArgs.length - 1) {
sb.append(",");
}
}
sb.append(")");
}
return sb.toString();
}
/**
* @return the inputArgsSchema
*/
public Schema getInputArgsSchema() {
return inputArgsSchema;
}
/**
* @param inputArgsSchema the inputArgsSchema to set
*/
public void setInputArgsSchema(Schema inputArgsSchema) {
this.inputArgsSchema = inputArgsSchema;
}
@Override
public boolean equals(Object other) {
if (other != null && other instanceof FuncSpec) {
FuncSpec ofs = (FuncSpec)other;
if (!className.equals(ofs.className)) return false;
if (ctorArgs == null && ofs.ctorArgs != null ||
ctorArgs != null && ofs.ctorArgs == null) {
return false;
}
if (ctorArgs != null && ofs.ctorArgs != null) {
if (ctorArgs.length != ofs.ctorArgs.length) return false;
for (int i = 0; i < ctorArgs.length; i++) {
if (!ctorArgs[i].equals(ofs.ctorArgs[i])) return false;
}
}
return Schema.equals(inputArgsSchema, ofs.inputArgsSchema, false, true);
} else {
return false;
}
}
@Override
public int hashCode() {
return getClassName().hashCode() + ctorArgs.length;
}
@Override
public FuncSpec clone() throws CloneNotSupportedException {
String[] args = null;
if (ctorArgs != null) {
args = new String[ctorArgs.length];
for (int i = 0; i < ctorArgs.length; i++) {
// Can use the same strings, they're immutable
args[i] = ctorArgs[i];
}
}
Schema s = null;
if (inputArgsSchema != null) s = inputArgsSchema.clone();
return new FuncSpec(className, args, s);
}
}