org.apache.juneau.config.internal.ConfigMap Maven / Gradle / Ivy
// ***************************************************************************************************************************
// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file *
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// * 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.juneau.config.internal;
import static org.apache.juneau.internal.StringUtils.*;
import static org.apache.juneau.config.event.ConfigEventType.*;
import java.io.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.concurrent.locks.*;
import org.apache.juneau.*;
import org.apache.juneau.config.event.*;
import org.apache.juneau.config.store.*;
import org.apache.juneau.internal.*;
/**
* Represents the parsed contents of a configuration.
*/
public class ConfigMap implements ConfigStoreListener {
private final ConfigStore store; // The store that created this object.
private volatile String contents; // The original contents of this object.
private final String name; // The name of this object.
private final static AsciiSet MOD_CHARS = AsciiSet.create("#$%&*+^@~");
// Changes that have been applied since the last load.
private final List changes = Collections.synchronizedList(new ArrayList());
// Registered listeners listening for changes during saves or reloads.
private final Set listeners = Collections.synchronizedSet(new HashSet());
// The parsed entries of this map with all changes applied.
final Map entries = Collections.synchronizedMap(new LinkedHashMap());
// The original entries of this map before any changes were applied.
final Map oentries = Collections.synchronizedMap(new LinkedHashMap());
private final ReadWriteLock lock = new ReentrantReadWriteLock();
/**
* Constructor.
*
* @param store The config store.
* @param name The config name.
* @throws IOException
*/
public ConfigMap(ConfigStore store, String name) throws IOException {
this.store = store;
this.name = name;
load(store.read(name));
}
ConfigMap(String contents) {
this.store = null;
this.name = null;
load(contents);
}
private ConfigMap load(String contents) {
if (contents == null)
contents = "";
this.contents = contents;
entries.clear();
oentries.clear();
List lines = new LinkedList<>();
try (Scanner scanner = new Scanner(contents)) {
while (scanner.hasNextLine()) {
String line = scanner.nextLine();
char c = firstChar(line);
if (c == '[') {
int c2 = StringUtils.lastNonWhitespaceChar(line);
String l = line.trim();
if (c2 != ']' || ! isValidNewSectionName(l.substring(1, l.length()-1)))
throw new ConfigException("Invalid section name found in configuration: {0}", line) ;
}
lines.add(line);
}
}
// Add [blank] section.
boolean inserted = false;
boolean foundComment = false;
for (ListIterator li = lines.listIterator(); li.hasNext();) {
String l = li.next();
char c = firstNonWhitespaceChar(l);
if (c != '#') {
if (c == 0 && foundComment) {
li.set("[]");
inserted = true;
}
break;
}
foundComment = true;
}
if (! inserted)
lines.add(0, "[]");
// Collapse any multi-lines.
ListIterator li = lines.listIterator(lines.size());
String accumulator = null;
while (li.hasPrevious()) {
String l = li.previous();
char c = firstChar(l);
if (c == '\t') {
c = firstNonWhitespaceChar(l);
if (c != '#') {
if (accumulator == null)
accumulator = l.substring(1);
else
accumulator = l.substring(1) + "\n" + accumulator;
li.remove();
}
} else if (accumulator != null) {
li.set(l + "\n" + accumulator);
accumulator = null;
}
}
lines = new ArrayList<>(lines);
int last = lines.size()-1;
int S1 = 1; // Looking for section.
int S2 = 2; // Found section, looking for start.
int state = S1;
List sections = new ArrayList<>();
for (int i = last; i >= 0; i--) {
String l = lines.get(i);
char c = firstChar(l);
if (state == S1) {
if (c == '[') {
state = S2;
}
} else {
if (c != '#' && (c == '[' || l.indexOf('=') != -1)) {
sections.add(new ConfigSection(lines.subList(i+1, last+1)));
last = i + 1;// (c == '[' ? i+1 : i);
state = (c == '[' ? S2 : S1);
}
}
}
sections.add(new ConfigSection(lines.subList(0, last+1)));
for (int i = sections.size() - 1; i >= 0; i--) {
ConfigSection cs = sections.get(i);
if (entries.containsKey(cs.name))
throw new ConfigException("Duplicate section found in configuration: [{0}]", cs.name);
entries.put(cs.name, cs);
}
oentries.putAll(entries);
return this;
}
//-----------------------------------------------------------------------------------------------------------------
// Getters
//-----------------------------------------------------------------------------------------------------------------
/**
* Reads an entry from this map.
*
* @param section
* The section name.
*
Must not be null .
*
Use blank to refer to the default section.
* @param key
* The entry key.
*
Must not be null .
* @return The entry, or null if the entry doesn't exist.
*/
public ConfigEntry getEntry(String section, String key) {
checkSectionName(section);
checkKeyName(key);
readLock();
try {
ConfigSection cs = entries.get(section);
return cs == null ? null : cs.entries.get(key);
} finally {
readUnlock();
}
}
/**
* Returns the pre-lines on the specified section.
*
*
* The pre-lines are all lines such as blank lines and comments that preceed a section.
*
* @param section
* The section name.
*
Must not be null .
*
Use blank to refer to the default section.
* @return
* An unmodifiable list of lines, or null if the section doesn't exist.
*/
public List getPreLines(String section) {
checkSectionName(section);
readLock();
try {
ConfigSection cs = entries.get(section);
return cs == null ? null : cs.preLines;
} finally {
readUnlock();
}
}
/**
* Returns the keys of the entries in the specified section.
*
* @return
* An unmodifiable set of keys.
*/
public Set getSections() {
return Collections.unmodifiableSet(entries.keySet());
}
/**
* Returns the keys of the entries in the specified section.
*
* @param section
* The section name.
*
Must not be null .
*
Use blank to refer to the default section.
* @return
* An unmodifiable set of keys, or an empty set if the section doesn't exist.
*/
public Set getKeys(String section) {
checkSectionName(section);
ConfigSection cs = entries.get(section);
return cs == null ? Collections.emptySet() : Collections.unmodifiableSet(cs.entries.keySet());
}
/**
* Returns true if this config has the specified section.
*
* @param section
* The section name.
*
Must not be null .
*
Use blank to refer to the default section.
* @return true if this config has the specified section.
*/
public boolean hasSection(String section) {
checkSectionName(section);
return entries.get(section) != null;
}
//-----------------------------------------------------------------------------------------------------------------
// Setters
//-----------------------------------------------------------------------------------------------------------------
/**
* Adds a new section or replaces the pre-lines on an existing section.
*
* @param section
* The section name.
*
Must not be null .
*
Use blank to refer to the default section.
* @param preLines
* The pre-lines on the section.
*
If null , the previous value will not be overwritten.
* @return This object (for method chaining).
*/
public ConfigMap setSection(String section, List preLines) {
checkSectionName(section);
return applyChange(true, ConfigEvent.setSection(section, preLines));
}
/**
* Adds or overwrites an existing entry.
*
* @param section
* The section name.
*
Must not be null .
*
Use blank to refer to the default section.
* @param key
* The entry key.
*
Must not be null .
* @param value
* The entry value.
*
If null , the previous value will not be overwritten.
* @param modifiers
* Optional modifiers.
*
If null , the previous value will not be overwritten.
* @param comment
* Optional comment.
*
If null , the previous value will not be overwritten.
* @param preLines
* Optional pre-lines.
*
If null , the previous value will not be overwritten.
* @return This object (for method chaining).
*/
public ConfigMap setEntry(String section, String key, String value, String modifiers, String comment, List preLines) {
checkSectionName(section);
checkKeyName(key);
if (modifiers != null && ! MOD_CHARS.containsOnly(modifiers))
throw new ConfigException("Invalid modifiers: {0}", modifiers);
return applyChange(true, ConfigEvent.setEntry(section, key, value, modifiers, comment, preLines));
}
/**
* Removes a section.
*
*
* This eliminates all entries in the section as well.
*
* @param section
* The section name.
*
Must not be null .
*
Use blank to refer to the default section.
* @return This object (for method chaining).
*/
public ConfigMap removeSection(String section) {
checkSectionName(section);
return applyChange(true, ConfigEvent.removeSection(section));
}
/**
* Removes an entry.
*
* @param section
* The section name.
*
Must not be null .
*
Use blank to refer to the default section.
* @param key
* The entry key.
*
Must not be null .
* @return This object (for method chaining).
*/
public ConfigMap removeEntry(String section, String key) {
checkSectionName(section);
checkKeyName(key);
return applyChange(true, ConfigEvent.removeEntry(section, key));
}
private ConfigMap applyChange(boolean addToChangeList, ConfigEvent ce) {
if (ce == null)
return this;
writeLock();
try {
String section = ce.getSection();
ConfigSection cs = entries.get(section);
if (ce.getType() == SET_ENTRY) {
if (cs == null) {
cs = new ConfigSection(section);
entries.put(section, cs);
}
ConfigEntry oe = cs.entries.get(ce.getKey());
if (oe == null)
oe = ConfigEntry.NULL;
cs.addEntry(
ce.getKey(),
ce.getValue() == null ? oe.value : ce.getValue(),
ce.getModifiers() == null ? oe.modifiers : ce.getModifiers(),
ce.getComment() == null ? oe.comment : ce.getComment(),
ce.getPreLines() == null ? oe.preLines : ce.getPreLines()
);
} else if (ce.getType() == SET_SECTION) {
if (cs == null) {
cs = new ConfigSection(section);
entries.put(section, cs);
}
if (ce.getPreLines() != null)
cs.setPreLines(ce.getPreLines());
} else if (ce.getType() == REMOVE_ENTRY) {
if (cs != null)
cs.entries.remove(ce.getKey());
} else if (ce.getType() == REMOVE_SECTION) {
if (cs != null)
entries.remove(section);
}
if (addToChangeList)
changes.add(ce);
} finally {
writeUnlock();
}
return this;
}
/**
* Overwrites the contents of the config file.
*
* @param contents The new contents of the config file.
* @param synchronous Wait until the change has been persisted before returning this map.
* @return This object (for method chaining).
* @throws IOException
* @throws InterruptedException
*/
public ConfigMap load(String contents, boolean synchronous) throws IOException, InterruptedException {
if (synchronous) {
final CountDownLatch latch = new CountDownLatch(1);
ConfigStoreListener l = new ConfigStoreListener() {
@Override
public void onChange(String contents) {
latch.countDown();
}
};
store.register(name, l);
store.write(name, null, contents);
latch.await(30, TimeUnit.SECONDS);
store.unregister(name, l);
} else {
store.write(name, null, contents);
}
return this;
}
//-----------------------------------------------------------------------------------------------------------------
// Lifecycle events
//-----------------------------------------------------------------------------------------------------------------
/**
* Persist any changes made to this map and signal all listeners.
*
*
* If the underlying contents of the file have changed, this will reload it and apply the changes
* on top of the modified file.
*
*
* Subsequent changes made to the underlying file will also be signaled to all listeners.
*
*
* We try saving the file up to 10 times.
*
If the file keeps changing on the file system, we throw an exception.
*
* @return This object (for method chaining).
* @throws IOException
*/
public ConfigMap commit() throws IOException {
writeLock();
try {
String newContents = asString();
for (int i = 0; i <= 10; i++) {
if (i == 10)
throw new ConfigException("Unable to store contents of config to store.");
String currentContents = store.write(name, contents, newContents);
if (currentContents == null)
break;
onChange(currentContents);
}
this.changes.clear();
} finally {
writeUnlock();
}
return this;
}
//-----------------------------------------------------------------------------------------------------------------
// Listeners
//-----------------------------------------------------------------------------------------------------------------
/**
* Registers an event listener on this map.
*
* @param listener The new listener.
* @return This object (for method chaining).
*/
public ConfigMap register(ConfigEventListener listener) {
listeners.add(listener);
return this;
}
/**
* Unregisters an event listener from this map.
*
* @param listener The listener to remove.
* @return This object (for method chaining).
*/
public ConfigMap unregister(ConfigEventListener listener) {
listeners.remove(listener);
return this;
}
@Override /* ConfigStoreListener */
public void onChange(String newContents) {
List changes = null;
writeLock();
try {
if (! StringUtils.isEquals(contents, newContents)) {
changes = findDiffs(newContents);
load(newContents);
// Reapply our changes on top of the modifications.
for (ConfigEvent ce : this.changes)
applyChange(false, ce);
}
} finally {
writeUnlock();
}
if (changes != null && ! changes.isEmpty())
signal(changes);
}
@Override /* Object */
public String toString() {
readLock();
try {
return asString();
} finally {
readUnlock();
}
}
/**
* Returns the values in this config map as a map of maps.
*
*
* This is considered a snapshot copy of the config map.
*
*
* The returned map is modifiable, but modifications to the returned map are not reflected in the config map.
*
* @return A copy of this config as a map of maps.
*/
public ObjectMap asMap() {
ObjectMap m = new ObjectMap();
readLock();
try {
for (ConfigSection cs : entries.values()) {
Map m2 = new LinkedHashMap<>();
for (ConfigEntry ce : cs.entries.values())
m2.put(ce.key, ce.value);
m.put(cs.name, m2);
}
} finally {
readUnlock();
}
return m;
}
/**
* Serializes this map to the specified writer.
*
* @param w The writer to serialize to.
* @return The same writer passed in.
* @throws IOException
*/
public Writer writeTo(Writer w) throws IOException {
readLock();
try {
for (ConfigSection cs : entries.values())
cs.writeTo(w);
} finally {
readUnlock();
}
return w;
}
/**
* Does a rollback of any changes on this map currently in memory.
*
* @return This object (for method chaining).
*/
public ConfigMap rollback() {
if (changes.size() > 0) {
writeLock();
try {
changes.clear();
load(contents);
} finally {
writeUnlock();
}
}
return this;
}
//-----------------------------------------------------------------------------------------------------------------
// Private methods
//-----------------------------------------------------------------------------------------------------------------
private void readLock() {
lock.readLock().lock();
}
private void readUnlock() {
lock.readLock().unlock();
}
private void writeLock() {
lock.writeLock().lock();
}
private void writeUnlock() {
lock.writeLock().unlock();
}
private void checkSectionName(String s) {
if (! ("".equals(s) || isValidNewSectionName(s)))
throw new IllegalArgumentException("Invalid section name: '" + s + "'");
}
private void checkKeyName(String s) {
if (! isValidKeyName(s))
throw new IllegalArgumentException("Invalid key name: '" + s + "'");
}
private boolean isValidKeyName(String s) {
if (s == null)
return false;
s = s.trim();
if (s.isEmpty())
return false;
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
if (c == '/' || c == '\\' || c == '[' || c == ']' || c == '=' || c == '#')
return false;
}
return true;
}
private boolean isValidNewSectionName(String s) {
if (s == null)
return false;
s = s.trim();
if (s.isEmpty())
return false;
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
if (c == '/' || c == '\\' || c == '[' || c == ']')
return false;
}
return true;
}
private void signal(List changes) {
for (ConfigEventListener l : listeners)
l.onConfigChange(changes);
}
private List findDiffs(String updatedContents) {
List changes = new ArrayList<>();
ConfigMap newMap = new ConfigMap(updatedContents);
for (ConfigSection ns : newMap.oentries.values()) {
ConfigSection s = oentries.get(ns.name);
if (s == null) {
//changes.add(ConfigEvent.setSection(ns.name, ns.preLines));
for (ConfigEntry ne : ns.entries.values()) {
changes.add(ConfigEvent.setEntry(ns.name, ne.key, ne.value, ne.modifiers, ne.comment, ne.preLines));
}
} else {
for (ConfigEntry ne : ns.oentries.values()) {
ConfigEntry e = s.oentries.get(ne.key);
if (e == null || ! isEquals(e.value, ne.value)) {
changes.add(ConfigEvent.setEntry(s.name, ne.key, ne.value, ne.modifiers, ne.comment, ne.preLines));
}
}
for (ConfigEntry e : s.oentries.values()) {
ConfigEntry ne = ns.oentries.get(e.key);
if (ne == null) {
changes.add(ConfigEvent.removeEntry(s.name, e.key));
}
}
}
}
for (ConfigSection s : oentries.values()) {
ConfigSection ns = newMap.oentries.get(s.name);
if (ns == null) {
//changes.add(ConfigEvent.removeSection(s.name));
for (ConfigEntry e : s.oentries.values())
changes.add(ConfigEvent.removeEntry(s.name, e.key));
}
}
return changes;
}
// This method should only be called from behind a lock.
private String asString() {
try {
StringWriter sw = new StringWriter();
for (ConfigSection cs : entries.values())
cs.writeTo(sw);
return sw.toString();
} catch (IOException e) {
throw new RuntimeException(e); // Not possible.
}
}
//---------------------------------------------------------------------------------------------
// ConfigSection
//---------------------------------------------------------------------------------------------
class ConfigSection {
final String name; // The config section name, or blank if the default section. Never null.
final List preLines = Collections.synchronizedList(new ArrayList());
private final String rawLine;
final Map oentries = Collections.synchronizedMap(new LinkedHashMap());
final Map entries = Collections.synchronizedMap(new LinkedHashMap());
/**
* Constructor.
*/
ConfigSection(String name) {
this.name = name;
this.rawLine = "[" + name + "]";
}
/**
* Constructor.
*/
ConfigSection(List lines) {
String name = null, rawLine = null;
int S1 = 1; // Looking for section.
int S2 = 2; // Found section, looking for end.
int state = S1;
int start = 0;
for (int i = 0; i < lines.size(); i++) {
String l = lines.get(i);
char c = StringUtils.firstNonWhitespaceChar(l);
if (state == S1) {
if (c == '[') {
int i1 = l.indexOf('['), i2 = l.indexOf(']');
name = l.substring(i1+1, i2).trim();
rawLine = l;
state = S2;
start = i+1;
} else {
preLines.add(l);
}
} else {
if (c != '#' && l.indexOf('=') != -1) {
ConfigEntry e = new ConfigEntry(l, lines.subList(start, i));
if (entries.containsKey(e.key))
throw new ConfigException("Duplicate entry found in section [{0}] of configuration: {1}", name, e.key);
entries.put(e.key, e);
start = i+1;
}
}
}
this.name = name;
this.rawLine = rawLine;
this.oentries.putAll(entries);
}
ConfigSection addEntry(String key, String value, String modifiers, String comment, List preLines) {
ConfigEntry e = new ConfigEntry(key, value, modifiers, comment, preLines);
this.entries.put(e.key, e);
return this;
}
ConfigSection setPreLines(List preLines) {
this.preLines.clear();
this.preLines.addAll(preLines);
return this;
}
Writer writeTo(Writer w) throws IOException {
for (String s : preLines)
w.append(s).append('\n');
if (! name.equals(""))
w.append(rawLine).append('\n');
else {
// Need separation between default prelines and first-entry prelines.
if (! preLines.isEmpty())
w.append('\n');
}
for (ConfigEntry e : entries.values())
e.writeTo(w);
return w;
}
}
}