ninja.leaping.configurate.loader.CommentHandlers Maven / Gradle / Ivy
/**
* Configurate
* Copyright (C) zml and Configurate contributors
*
* Licensed 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 ninja.leaping.configurate.loader;
import com.google.common.base.Function;
import com.google.common.base.Optional;
import com.google.common.collect.Collections2;
import java.io.BufferedReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
/**
* Created by zml on 20.02.15.
*/
public enum CommentHandlers implements CommentHandler {
HASH("#"),
DOUBLE_SLASH("//"),
/**
* Block comments delineated by
*/
SLASH_BLOCK() {
@Override
public Optional extractHeader(BufferedReader reader) throws IOException {
final StringBuilder build = new StringBuilder();
String line = reader.readLine();
if (line == null) {
return Optional.absent();
}
if (!line.trim().startsWith("/*")) {
return Optional.absent();
}
line = line.substring(line.indexOf("/*") + 2);
if (handleSingleLine(build, line)) {
for (line = reader.readLine(); line != null; line = reader.readLine()) {
if (!handleSingleLine(build, line)) {
break;
}
}
}
line = reader.readLine();
if (!(line == null || line.trim().isEmpty())) { // Require a blank line after a comment to make it a header
return Optional.absent();
}
if (build.length() > 0) {
return Optional.of(build.toString());
} else {
return Optional.absent();
}
}
private boolean handleSingleLine(StringBuilder builder, String line) {
boolean moreLines = true;
if (line.trim().endsWith("*/")) {
line = line.substring(0, line.lastIndexOf("*/"));
if (line.endsWith(" ")) {
line = line.substring(0, line.length() - 1);
}
moreLines = false;
if (line.isEmpty()) {
return false;
}
}
if (line.trim().startsWith("*")) {
line = line.substring(line.indexOf("*") + 1);
}
if (line.startsWith(" ")) {
line = line.substring(1);
}
if (builder.length() > 0) {
builder.append(AbstractConfigurationLoader.LINE_SEPARATOR);
}
builder.append(line);
return moreLines;
}
@Override
public Collection toComment(Collection lines) {
if (lines.size() == 1) {
return Collections2.transform(lines, new Function() {
@Override
public String apply(String input) {
return "/* " + input + " */";
}
});
} else {
Collection ret = new ArrayList<>();
ret.add("/*");
ret.addAll(Collections2.transform(lines, new Function() {
@Override
public String apply(String input) {
return " * " + input;
}
}));
ret.add(" */");
return ret;
}
}
}
;
private static final int READAHEAD_LEN = 4096;
private final String commentPrefix;
private CommentHandlers() {
this.commentPrefix = null;
}
private CommentHandlers(String commentPrefix) {
this.commentPrefix = commentPrefix;
}
public Optional extractHeader(BufferedReader reader) throws IOException {
StringBuilder build = new StringBuilder();
for (String line = reader.readLine(); line != null; line = reader.readLine()) {
if (line.trim().startsWith(commentPrefix)) {
line = line.substring(line.indexOf(commentPrefix) + 1);
if (line.startsWith(" ")) {
line = line.substring(1);
}
if (build.length() > 0) {
build.append(AbstractConfigurationLoader.LINE_SEPARATOR);
}
build.append(line);
} else {
if (line.trim().isEmpty()) {
break;
} else {
return Optional.absent();
}
}
}
// We've reached the end of the document?
return build.length() > 0 ? Optional.fromNullable(build.toString()) : Optional.absent();
}
@Override
public Collection toComment(Collection lines) {
return Collections2.transform(lines, new Function() {
@Override
public String apply(String s) {
if (s.startsWith(" ")) {
return commentPrefix + s;
} else {
return commentPrefix + " " + s;
}
}
});
}
public static String extractComment(BufferedReader reader, CommentHandler... allowedHeaderTypes) throws IOException {
reader.mark(READAHEAD_LEN);
for (CommentHandler handler : allowedHeaderTypes) {
Optional comment = handler.extractHeader(reader);
if (!comment.isPresent()) {
reader.reset();
} else {
return comment.get();
}
}
return null;
}
}