/*
* Copyright: Almende B.V. (2014), Rotterdam, The Netherlands
* License: The Apache Software License, Version 2.0
*/
package com.almende.eve.state.file;
import java.io.File;
import java.io.IOException;
import java.lang.ref.WeakReference;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.logging.Level;
import java.util.logging.Logger;
import com.almende.eve.capabilities.AbstractCapabilityBuilder;
import com.almende.eve.state.State;
import com.almende.eve.state.StateService;
import com.fasterxml.jackson.databind.node.ObjectNode;
/**
* A factory for creating FileState objects.
*/
public class FileStateBuilder extends AbstractCapabilityBuilder<State> {
private static final Logger LOG = Logger.getLogger(FileStateBuilder.class
.getSimpleName());
private static Map<String, FileStateProvider> instances = new ConcurrentHashMap<String, FileStateProvider>(
10);
@Override
public State build() {
final FileStateProvider provider = getInstanceByParams(getParams());
if (provider != null) {
return provider.get(getParams());
} else {
LOG.warning("Couldn't get FileStateProvider!");
return null;
}
}
/**
* Gets the instance by params.
*
* @param params
* the params
* @return the instance by params
*/
private FileStateProvider getInstanceByParams(final ObjectNode params) {
final FileStateConfig config = FileStateConfig.decorate(params);
final String key = config.getPath();
if (instances.containsKey(key)) {
return instances.get(key);
} else {
synchronized (instances) {
if (!instances.containsKey(key)) {
final FileStateProvider result = new FileStateProvider(
params);
if (result != null) {
instances.put(key, result);
}
}
return instances.get(key);
}
}
}
class FileStateProvider implements StateService {
private String path = null;
private Boolean json = true;
private final Map<String, WeakReference<State>> states = new ConcurrentHashMap<String, WeakReference<State>>(
10);
/**
* Instantiates a new file state provider.
*
* @param params
* the params
*/
public FileStateProvider(final ObjectNode params) {
final FileStateConfig config = FileStateConfig.decorate(params);
json = config.getJson();
setPath(config.getPath());
}
/**
* Instantiates a new file state provider.
*
* @param path
* the path
* @param json
* the json
* @param multilevel
* Whether the path contains a subdirectory for agent
* categories.
*/
public FileStateProvider(final String path, final Boolean json,
final Boolean multilevel) {
this.json = json;
setPath(path);
}
/**
* Instantiates a new file state factory.
*
* @param path
* the path
* @param json
* the json
*/
public FileStateProvider(final String path, final Boolean json) {
this.json = json;
setPath(path);
}
/**
* Instantiates a new file state factory.
*
* @param path
* the path
*/
public FileStateProvider(final String path) {
this(path, false);
}
/**
* Set the path where the agents data will be stored.
*
* @param path
* the new path
*/
private synchronized void setPath(final String path) {
String actualPath = path;
if (actualPath == null) {
actualPath = ".eveagents";
LOG.warning("Config parameter 'path' missing in State "
+ "configuration. Using the default path '" + path
+ "'");
}
if (!actualPath.endsWith("/")) {
actualPath += "/";
}
this.path = actualPath;
// make the directory
final File file = new File(actualPath);
if (!file.exists() && !file.mkdir()) {
LOG.severe("Could not create State folder!");
throw new IllegalStateException();
}
// log info
String info = "Agents will be stored in ";
try {
info += file.getCanonicalPath();
} catch (final IOException e) {
info += actualPath;
}
LOG.info(info
+ ". "
+ (json ? "(stored in JSON format)"
: "(stored in JavaObject format)"));
}
/**
* Gets the.
*
* @param params
* the params
* @return the state
*/
public State get(final ObjectNode params) {
final FileStateConfig config = FileStateConfig.decorate(params);
final String agentId = config.getId();
if (agentId == null) {
LOG.warning("Parameter 'id' is required for a file State.");
return null;
}
State state = null;
try {
if (!exists(agentId)) {
final String filename = getFilename(agentId);
final File file = new File(filename);
file.createNewFile();
}
if (states.containsKey(agentId)) {
WeakReference<State> ref = states.get(agentId);
if (ref != null) {
state = ref.get();
}
}
if (state == null) {
if (json) {
state = new ConcurrentJsonFileState(agentId,
getFilename(agentId), this, params);
} else {
state = new ConcurrentSerializableFileState(agentId,
getFilename(agentId), this, params);
}
states.put(agentId, new WeakReference<State>(state));
}
} catch (IOException e) {
LOG.log(Level.WARNING, "Couldn't create FileState", e);
}
return state;
}
/**
* Test if a state with given agentId exists.
*
* @param agentId
* the agent id
* @return true, if successful
*/
public boolean exists(final String agentId) {
final File file = new File(getFilename(agentId));
return file.exists();
}
/**
* Get the filename of the saved.
*
* @param agentId
* the agent id
* @return the filename
*/
private String getFilename(final String agentId) {
final String apath = path != null ? path : "./";
return apath + agentId;
}
/*
* (non-Javadoc)
* @see
* com.almende.eve.state.StateService#delete(com.almende.eve.state.State)
*/
@Override
public void delete(final State instance) {
delete(instance, false);
}
/*
* (non-Javadoc)
* @see
* com.almende.eve.state.StateService#delete(com.almende.eve.state.State)
*/
@Override
public void delete(final State instance, final Boolean instanceOnly) {
final String id = instance.getId();
if(!instanceOnly) {
final File file = new File(getFilename(id));
if (file.exists()) {
file.delete();
}
}
states.remove(id);
}
/*
* (non-Javadoc)
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
final Map<String, Object> data = new HashMap<String, Object>();
data.put("class", this.getClass().getName());
data.put("path", path);
return data.toString();
}
@Override
public Set<String> getStateIds() {
final Set<String> result = new HashSet<String>();
try {
Iterator<Path> iter = Files.newDirectoryStream(
Paths.get(this.path)).iterator();
while (iter.hasNext()) {
final Path path = iter.next();
final File file = path.toFile();
if (!file.isDirectory()) {
result.add(path.getFileName().toString());
}
}
} catch (IOException e) {
LOG.log(Level.WARNING,
"Couldn't read the path at:" + this.path, e);
}
return result;
}
}
}