84 lines
3.1 KiB
Java
84 lines
3.1 KiB
Java
package net.minecraft.network.chat;
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import it.unimi.dsi.fastutil.objects.ObjectArrayList;
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import it.unimi.dsi.fastutil.objects.ObjectList;
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import org.jetbrains.annotations.Nullable;
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public class LastSeenMessagesValidator {
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private final int lastSeenCount;
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private final ObjectList<LastSeenTrackedEntry> trackedMessages = new ObjectArrayList<>();
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@Nullable
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private MessageSignature lastPendingMessage;
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public LastSeenMessagesValidator(int lastSeenCount) {
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this.lastSeenCount = lastSeenCount;
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for (int i = 0; i < lastSeenCount; i++) {
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this.trackedMessages.add(null);
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}
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}
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public void addPending(MessageSignature signature) {
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if (!signature.equals(this.lastPendingMessage)) {
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this.trackedMessages.add(new LastSeenTrackedEntry(signature, true));
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this.lastPendingMessage = signature;
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}
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}
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public int trackedMessagesCount() {
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return this.trackedMessages.size();
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}
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public void applyOffset(int offset) throws LastSeenMessagesValidator.ValidationException {
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int i = this.trackedMessages.size() - this.lastSeenCount;
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if (offset >= 0 && offset <= i) {
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this.trackedMessages.removeElements(0, offset);
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} else {
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throw new LastSeenMessagesValidator.ValidationException("Advanced last seen window by " + offset + " messages, but expected at most " + i);
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}
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}
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public LastSeenMessages applyUpdate(LastSeenMessages.Update update) throws LastSeenMessagesValidator.ValidationException {
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this.applyOffset(update.offset());
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ObjectList<MessageSignature> objectList = new ObjectArrayList<>(update.acknowledged().cardinality());
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if (update.acknowledged().length() > this.lastSeenCount) {
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throw new LastSeenMessagesValidator.ValidationException(
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"Last seen update contained " + update.acknowledged().length() + " messages, but maximum window size is " + this.lastSeenCount
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);
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} else {
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for (int i = 0; i < this.lastSeenCount; i++) {
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boolean bl = update.acknowledged().get(i);
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LastSeenTrackedEntry lastSeenTrackedEntry = (LastSeenTrackedEntry)this.trackedMessages.get(i);
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if (bl) {
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if (lastSeenTrackedEntry == null) {
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throw new LastSeenMessagesValidator.ValidationException("Last seen update acknowledged unknown or previously ignored message at index " + i);
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}
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this.trackedMessages.set(i, lastSeenTrackedEntry.acknowledge());
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objectList.add(lastSeenTrackedEntry.signature());
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} else {
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if (lastSeenTrackedEntry != null && !lastSeenTrackedEntry.pending()) {
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throw new LastSeenMessagesValidator.ValidationException(
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"Last seen update ignored previously acknowledged message at index " + i + " and signature " + lastSeenTrackedEntry.signature()
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);
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}
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this.trackedMessages.set(i, null);
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}
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}
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LastSeenMessages lastSeenMessages = new LastSeenMessages(objectList);
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if (!update.verifyChecksum(lastSeenMessages)) {
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throw new LastSeenMessagesValidator.ValidationException("Checksum mismatch on last seen update: the client and server must have desynced");
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} else {
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return lastSeenMessages;
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}
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}
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}
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public static class ValidationException extends Exception {
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public ValidationException(String message) {
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super(message);
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}
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}
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}
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