82 lines
2.5 KiB
Java
82 lines
2.5 KiB
Java
package net.minecraft.util.eventlog;
|
|
|
|
import com.google.gson.Gson;
|
|
import com.google.gson.JsonElement;
|
|
import com.mojang.serialization.Codec;
|
|
import com.mojang.serialization.JsonOps;
|
|
import java.io.Closeable;
|
|
import java.io.IOException;
|
|
import java.io.Writer;
|
|
import java.nio.channels.Channels;
|
|
import java.nio.channels.FileChannel;
|
|
import java.nio.charset.StandardCharsets;
|
|
import java.nio.file.Path;
|
|
import java.nio.file.StandardOpenOption;
|
|
import java.util.concurrent.atomic.AtomicInteger;
|
|
import org.jetbrains.annotations.Nullable;
|
|
|
|
public class JsonEventLog<T> implements Closeable {
|
|
private static final Gson GSON = new Gson();
|
|
private final Codec<T> codec;
|
|
final FileChannel channel;
|
|
private final AtomicInteger referenceCount = new AtomicInteger(1);
|
|
|
|
public JsonEventLog(Codec<T> codec, FileChannel channel) {
|
|
this.codec = codec;
|
|
this.channel = channel;
|
|
}
|
|
|
|
public static <T> JsonEventLog<T> open(Codec<T> codec, Path path) throws IOException {
|
|
FileChannel fileChannel = FileChannel.open(path, StandardOpenOption.WRITE, StandardOpenOption.READ, StandardOpenOption.CREATE);
|
|
return new JsonEventLog<>(codec, fileChannel);
|
|
}
|
|
|
|
public void write(T data) throws IOException {
|
|
JsonElement jsonElement = this.codec.encodeStart(JsonOps.INSTANCE, data).getOrThrow(IOException::new);
|
|
this.channel.position(this.channel.size());
|
|
Writer writer = Channels.newWriter(this.channel, StandardCharsets.UTF_8);
|
|
GSON.toJson(jsonElement, GSON.newJsonWriter(writer));
|
|
writer.write(10);
|
|
writer.flush();
|
|
}
|
|
|
|
public JsonEventLogReader<T> openReader() throws IOException {
|
|
if (this.referenceCount.get() <= 0) {
|
|
throw new IOException("Event log has already been closed");
|
|
} else {
|
|
this.referenceCount.incrementAndGet();
|
|
final JsonEventLogReader<T> jsonEventLogReader = JsonEventLogReader.create(this.codec, Channels.newReader(this.channel, StandardCharsets.UTF_8));
|
|
return new JsonEventLogReader<T>() {
|
|
private volatile long position;
|
|
|
|
@Nullable
|
|
@Override
|
|
public T next() throws IOException {
|
|
Object var1;
|
|
try {
|
|
JsonEventLog.this.channel.position(this.position);
|
|
var1 = jsonEventLogReader.next();
|
|
} finally {
|
|
this.position = JsonEventLog.this.channel.position();
|
|
}
|
|
|
|
return (T)var1;
|
|
}
|
|
|
|
public void close() throws IOException {
|
|
JsonEventLog.this.releaseReference();
|
|
}
|
|
};
|
|
}
|
|
}
|
|
|
|
public void close() throws IOException {
|
|
this.releaseReference();
|
|
}
|
|
|
|
void releaseReference() throws IOException {
|
|
if (this.referenceCount.decrementAndGet() <= 0) {
|
|
this.channel.close();
|
|
}
|
|
}
|
|
}
|