org.codelibs.elasticsearch.velocity.service.VelocityScriptEngineService Maven / Gradle / Ivy
package org.codelibs.elasticsearch.velocity.service;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.lang.ref.SoftReference;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import org.apache.velocity.Template;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.VelocityEngine;
import org.apache.velocity.context.Context;
import org.apache.velocity.exception.VelocityException;
import org.elasticsearch.common.bytes.BytesReference;
import org.elasticsearch.common.component.AbstractComponent;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.io.UTF8StreamWriter;
import org.elasticsearch.common.io.stream.BytesStreamOutput;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.env.Environment;
import org.elasticsearch.script.CompiledScript;
import org.elasticsearch.script.ExecutableScript;
import org.elasticsearch.script.ScriptEngineService;
import org.elasticsearch.script.SearchScript;
import org.elasticsearch.search.lookup.SearchLookup;
public class VelocityScriptEngineService extends AbstractComponent implements
ScriptEngineService {
public static String VELOCITY_SCRIPT_PROPS = "script.velocity.props.";
/**
* Thread local UTF8StreamWriter to store template execution results in,
* thread local to save object creation.
*/
private static ThreadLocal> utf8StreamWriter = new ThreadLocal<>();
private VelocityEngine velocityEngine;
private File workDir;
private List templateFileList = new LinkedList();
/**
* If exists, reset and return, otherwise create, reset and return a writer.
*/
private static UTF8StreamWriter utf8StreamWriter() {
final SoftReference ref = utf8StreamWriter.get();
UTF8StreamWriter writer = ref == null ? null : ref.get();
if (writer == null) {
writer = new UTF8StreamWriter(1024 * 4);
utf8StreamWriter.set(new SoftReference<>(writer));
}
writer.reset();
return writer;
}
@Inject
public VelocityScriptEngineService(final Settings settings,
final Environment env) {
super(settings);
Object workDirPath = settings.get("script.velocity.work_dir");
if (workDirPath == null) {
workDir = env.tmpFile().resolve("velocity").toFile();
} else {
workDir = new File(workDirPath.toString());
}
if (!workDir.exists() && !workDir.mkdirs()) {
throw new VelocityException(
"Could not create a working directory: "
+ workDir.getAbsolutePath());
}
final Properties props = new Properties();
for (final Map.Entry entry : settings
.getByPrefix(VELOCITY_SCRIPT_PROPS).getAsMap().entrySet()) {
props.put(entry.getKey(), entry.getValue());
}
final String resourceLoader = (String) props.get("resource.loader");
if (resourceLoader != null) {
props.put("resource.loader", "WORK_TMPL,ES_TMPL," + resourceLoader);
} else {
props.put("resource.loader", "WORK_TMPL,ES_TMPL");
}
initPropertyValue(props, "WORK_TMPL.resource.loader.class",
"org.apache.velocity.runtime.resource.loader.FileResourceLoader");
initPropertyValue(props, "WORK_TMPL.resource.loader.path",
workDir.getAbsolutePath());
initPropertyValue(props, "WORK_TMPL.resource.loader.cache", "true");
initPropertyValue(props,
"WORK_TMPL.resource.loader.modificationCheckInterval", "0");
initPropertyValue(props, "ES_TMPL.resource.loader.class",
"org.apache.velocity.runtime.resource.loader.FileResourceLoader");
initPropertyValue(props, "ES_TMPL.resource.loader.path",
env.configFile().resolve("scripts").toFile().getAbsolutePath());
initPropertyValue(props, "ES_TMPL.resource.loader.cache", "true");
initPropertyValue(props,
"ES_TMPL.resource.loader.modificationCheckInterval", "60");
initPropertyValue(props, "velocimacro.library.autoreload", "false");
initPropertyValue(props, "input.encoding", "UTF-8");
initPropertyValue(props, "output.encoding", "UTF-8");
initPropertyValue(props, "runtime.log", env.logsFile()
.resolve("velocity.log").toFile().getAbsolutePath());
velocityEngine = new VelocityEngine(props);
velocityEngine.init();
}
private boolean initPropertyValue(final Properties props, final String key,
final String value) {
if (!props.containsKey(key)) {
props.put(key, value);
return true;
}
return false;
}
@Override
public String[] types() {
return new String[] { "velocity" };
}
@Override
public String[] extensions() {
return new String[] { "vm", "velocity" };
}
@Override
public boolean sandboxed() {
return false;
}
@Override
public Object compile(final String script) {
final VelocityScriptTemplate scriptTemplate = new VelocityScriptTemplate(
velocityEngine, workDir, script);
final File templateFile = scriptTemplate.getTemplateFile();
if (templateFile != null) {
synchronized (templateFileList) {
templateFileList.add(templateFile);
}
}
return scriptTemplate;
}
@Override
public ExecutableScript executable(CompiledScript compiledScript,
Map vars) {
return new VelocityExecutableScript(
(VelocityScriptTemplate) compiledScript.compiled(), vars);
}
@Override
public SearchScript search(CompiledScript compiledScript,
SearchLookup lookup, Map vars) {
throw new UnsupportedOperationException();
}
@Override
public Object execute(CompiledScript compiledScript,
Map vars) {
final BytesStreamOutput result = new BytesStreamOutput();
final UTF8StreamWriter writer = utf8StreamWriter().setOutput(result);
try {
((VelocityScriptTemplate) compiledScript.compiled())
.merge(new VelocityContext(vars), writer);
writer.flush();
} catch (final IOException e) {
logger.error(
"Could not execute query template (failed to flush writer): ",
e);
} finally {
try {
writer.close();
} catch (final IOException e) {
logger.error(
"Could not execute query template (failed to close writer): ",
e);
}
}
return result.bytes();
}
@Override
public Object unwrap(final Object value) {
return value;
}
@Override
public void scriptRemoved(final CompiledScript script) {
final Object compiled = script.compiled();
if (compiled instanceof VelocityScriptTemplate) {
final File templateFile = ((VelocityScriptTemplate) compiled)
.getTemplateFile();
if (templateFile != null) {
synchronized (templateFileList) {
templateFileList.remove(templateFile);
}
if (logger.isDebugEnabled()) {
logger.debug("Deleting {}", templateFile.getAbsolutePath());
}
if (!templateFile.delete()) {
logger.warn("Failed to delete {}.",
templateFile.getAbsolutePath());
}
}
}
}
@Override
public void close() {
synchronized (templateFileList) {
for (final File templateFile : templateFileList) {
if (logger.isDebugEnabled()) {
logger.debug("Deleting {}", templateFile.getAbsolutePath());
}
if (!templateFile.delete()) {
logger.warn("Failed to delete {}.",
templateFile.getAbsolutePath());
}
}
}
}
public static class VelocityScriptTemplate {
private Template template;
private File templateFile;
private String script;
private VelocityEngine velocityEngine;
public VelocityScriptTemplate(final VelocityEngine velocityEngine,
final File workDir, final String script) {
this.velocityEngine = velocityEngine;
if (script.startsWith("##cache")) {
String encoding = (String) velocityEngine
.getProperty("input.encoding");
if (encoding == null) {
encoding = "UTF-8";
}
if (!workDir.exists() && !workDir.mkdirs()) {
throw new VelocityException(
"Could not create a working directory: "
+ workDir.getAbsolutePath());
}
templateFile = null;
BufferedWriter bw = null;
try {
templateFile = File.createTempFile("templ", ".vm", workDir);
bw = new BufferedWriter(new OutputStreamWriter(
new FileOutputStream(templateFile), encoding));
bw.write(script);
bw.flush();
} catch (final IOException e) {
throw new VelocityException(
"Failed to create a template file.", e);
} finally {
if (bw != null) {
try {
bw.close();
} catch (final IOException e) {
// ignore
}
}
}
template = velocityEngine.getTemplate(templateFile.getName());
} else {
this.script = script;
}
}
public File getTemplateFile() {
return templateFile;
}
public void merge(final Context context, final Writer writer) {
if (script != null) {
int length = script.length();
if (length > 10) {
length = 10;
}
velocityEngine.evaluate(context, writer,
script.substring(0, length), script);
} else {
template.merge(context, writer);
}
}
}
private class VelocityExecutableScript implements ExecutableScript {
/** Compiled template object. */
private VelocityScriptTemplate context;
/** Parameters to fill above object with. */
private Map vars;
/**
* @param template the compiled template object
* @param vars the parameters to fill above object with
**/
public VelocityExecutableScript(final VelocityScriptTemplate context,
final Map vars) {
this.context = context;
if (vars == null) {
this.vars = Collections.emptyMap();
} else {
this.vars = vars;
}
}
@Override
public void setNextVar(final String name, final Object value) {
vars.put(name, value);
}
@Override
public Object run() {
final BytesStreamOutput result = new BytesStreamOutput();
final UTF8StreamWriter writer = utf8StreamWriter()
.setOutput(result);
try {
context.merge(new VelocityContext(vars), writer);
writer.flush();
} catch (final Exception e) {
logger.error(
"Could not execute query template (failed to flush writer): ",
e);
} finally {
try {
writer.close();
} catch (final IOException e) {
logger.error(
"Could not execute query template (failed to close writer): ",
e);
}
}
BytesReference bytes = result.bytes();
if (logger.isDebugEnabled()) {
logger.debug("output: {}", new String(bytes.array()));
}
return bytes;
}
@Override
public Object unwrap(final Object value) {
return value;
}
}
}
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