com.nflabs.zeppelin.zengine.stmt.Q Maven / Gradle / Ivy
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Zengine is java framework for data analysis on Hadoop. see http://nflabs.github.io/zeppelin/#/zengine
package com.nflabs.zeppelin.zengine.stmt;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URI;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import javax.script.Bindings;
import javax.script.ScriptContext;
import javax.script.ScriptEngine;
import javax.script.ScriptException;
import javax.script.SimpleBindings;
import org.apache.commons.lang.StringEscapeUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.nflabs.zeppelin.driver.ZeppelinConnection;
import com.nflabs.zeppelin.driver.ZeppelinDriver;
import com.nflabs.zeppelin.result.Result;
import com.nflabs.zeppelin.zengine.ParamInfo;
import com.nflabs.zeppelin.zengine.ZContext;
import com.nflabs.zeppelin.zengine.ZException;
import com.nflabs.zeppelin.zengine.ZWebContext;
import com.nflabs.zeppelin.zengine.Zengine;
import com.sun.script.jruby.JRubyScriptEngineFactory;
/**
* Q stands for Query
* @author moon
*
*/
public class Q extends Z {
protected String query;
private List resources = new LinkedList();
Result cachedResultDataObject;
transient boolean initialized = false;
transient static final String ARG_VAR_NAME="arg";
transient static final String INPUT_VAR_NAME="in";
transient static final String OUTPUT_VAR_NAME="out";
/**
* Create with given query. Query is single HiveQL statement.
* Query can erb template. ZContext is injected to the template
* @param query
* @param z
* @param driver
* @throws ZException
*/
public Q(String query) throws ZException{
super();
this.query = query;
initialize();
}
private Logger logger(){
return LoggerFactory.getLogger(Q.class);
}
protected void initialize() throws ZException {
if(initialized){
return ;
}
initialized = true;
}
/**
* Adds resource required by this query.
* Either normal file or jar lib.
* Will be automatically added before executing this query.
* i.e. ADD FILE [uri] or ADD JAR [uri] is executed automatically.
* @param r
* @return
*/
public Q withResource(URI r){
resources.add(r);
return this;
}
protected String getQuery(BufferedReader erb, ZContext zcontext) throws ZException{
return evalErb(erb, zcontext);
}
private static ScriptEngine rubyScriptEngine;
static {
JRubyScriptEngineFactory factory = new JRubyScriptEngineFactory();
rubyScriptEngine = factory.getScriptEngine();
StringBuffer rubyScript = new StringBuffer();
rubyScript.append("require 'erb'\n");
try {
rubyScriptEngine.eval(rubyScript.toString());
} catch (ScriptException e) {
e.printStackTrace();
}
}
protected String evalErb(BufferedReader erb, Object zcontext) throws ZException{
synchronized(rubyScriptEngine){
StringBuffer rubyScript = new StringBuffer();
Bindings bindings = rubyScriptEngine.createBindings();
bindings.put("z", zcontext);
rubyScriptEngine.setBindings(bindings, ScriptContext.ENGINE_SCOPE);
rubyScript.append("require 'erb'\n");
rubyScript.append("z = $z\n");
try {
String line = null;
rubyScript.append("erb = \"\"\n");
boolean first = true;
while((line = erb.readLine())!=null){
String newline;
if(first==false){
newline = "\\n";
} else {
newline = "";
first = false;
}
rubyScript.append("erb += \""+newline+StringEscapeUtils.escapeJavaScript(line)+"\"\n");
}
} catch (IOException e1) {
throw new ZException(e1);
}
rubyScript.append("$e = ERB.new(erb).result(binding)\n");
try {
logger().debug("rubyScript to run : \n"+rubyScript.toString());
rubyScriptEngine.eval(rubyScript.toString(), bindings);
} catch (ScriptException e) {
throw new ZException(e);
}
String q = (String) rubyScriptEngine.getBindings(ScriptContext.ENGINE_SCOPE).get("e");
return nonNullString(q);
}
}
private String nonNullString(String q) {
return q == null ? "" : q;
}
protected String evalWebTemplate(BufferedReader erb, ZWebContext zWebContext) throws ZException{
return evalErb(erb, zWebContext);
}
/**
* Get query to be executed.
* Template is evaluated with ZContext.
* And CREATE TABLE or CREATE VIEW statement is added in front of query according to settings
*/
@Override
public String getQuery() throws ZException{
ByteArrayInputStream ins = new ByteArrayInputStream(query.getBytes());
BufferedReader erb = new BufferedReader(new InputStreamReader(ins));
ZContext zContext = new ZContext( hasPrev() ? prev().name() : null, name(), query, params);
String q = getQuery(erb, zContext);
try {ins.close();} catch (IOException e) {}
return q;
}
/**
* Get web representation of result.
* Printed as a table
*/
public InputStream readWebResource(String path) throws ZException{
initialize();
ZWebContext zWebContext = null;
try{
zWebContext = new ZWebContext(result());
} catch(ZException e){
}
InputStream ins = this.getClass().getResourceAsStream("/table.erb");
BufferedReader erb = new BufferedReader(new InputStreamReader(ins));
String q = evalWebTemplate(erb, zWebContext);
try {
ins.close();
} catch (IOException e) {
logger().error("Assert", e);
}
return new ByteArrayInputStream(q.getBytes());
}
/**
* Return URI of resources
*/
@Override
public List getResources() throws ZException {
if(prev()==null){
return resources;
} else {
List r = new LinkedList();
r.addAll(resources);
r.addAll(prev().getResources());
return r;
}
}
/**
* When this object is no longer used, this method is invoked to cleanup results.
*/
@Override
public String getReleaseQuery() throws ZException {
return null;
}
/**
* Check if it is capable of rendering web
*/
@Override
public boolean isWebEnabled() {
if(next()==null) return true;
else return false;
}
@Override
protected Map extractParams() throws ZException {
Map paramInfos = new HashMap();
ByteArrayInputStream ins = new ByteArrayInputStream(query.getBytes());
BufferedReader erb = new BufferedReader(new InputStreamReader(ins));
ZContext zContext = new ZContext( (prev()==null) ? null : prev().name(), name(), query, params);
try {
getQuery(erb, zContext);
} catch (ZException e1) {
logger().debug("dry run error", e1);
}
try {ins.close();} catch (IOException e) {}
ZWebContext zWebContext = null;
if(isWebEnabled()==true){
zWebContext = new ZWebContext(null);
InputStream in = this.getClass().getResourceAsStream("/table.erb");
erb = new BufferedReader(new InputStreamReader(in));
try {
evalWebTemplate(erb, zWebContext);
} catch (ZException e1) {
logger().debug("dry run error", e1);
}
try {
ins.close();
} catch (IOException e) {
logger().error("Assert", e);
}
}
if(zWebContext!=null){
paramInfos.putAll(zWebContext.getParamInfos());
}
if(zContext!=null){
paramInfos.putAll(zContext.getParamInfos());
}
return paramInfos;
}
}