Transaction debugging

OriginAware.java

package io.github.daomephsta;

import java.lang.StackWalker.StackFrame;
import java.util.List;

public interface OriginAware
{
    public List<StackFrame> silverfish_getOrigin();
}

TransactionManagerImplMixin.java

package io.github.daomephsta.mixin;

import java.lang.StackWalker.StackFrame;
import java.util.Iterator;

import org.spongepowered.asm.mixin.Mixin;
import org.spongepowered.asm.mixin.Shadow;
import org.spongepowered.asm.mixin.injection.At;
import org.spongepowered.asm.mixin.injection.Inject;
import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
import io.github.daomephsta.OriginAware;
import net.fabricmc.fabric.api.transfer.v1.transaction.Transaction;
import net.fabricmc.fabric.api.transfer.v1.transaction.TransactionContext;
import net.fabricmc.fabric.impl.transfer.transaction.TransactionManagerImpl;

@Mixin(TransactionManagerImpl.class)
public abstract class TransactionManagerImplMixin
{
    @Shadow
    public abstract TransactionContext getCurrentUnsafe();

    @Inject(method = "openOuter",
        at = @At(value = "NEW", target = "java.lang.IllegalStateException"))
    private void silverfish_improveOuterTransactionError(CallbackInfoReturnable<Transaction> info)
    {
        var originAware = (OriginAware) getCurrentUnsafe();
        var origin = new StringBuilder().append("Origin of current outer transaction\n");
        for (Iterator<StackFrame> iter = originAware.silverfish_getOrigin().iterator(); iter.hasNext();)
        {
            StackFrame frame = iter.next();
            origin.append("\tat ").append(frame);
            if (iter.hasNext()) origin.append('\n');
        }
        System.err.println(origin);
    }
}

TransactionOriginTracer.java

package io.github.daomephsta.mixin;

import java.lang.StackWalker.Option;
import java.lang.StackWalker.StackFrame;
import java.util.List;
import java.util.stream.Stream;

import org.spongepowered.asm.mixin.Final;
import org.spongepowered.asm.mixin.Mixin;
import org.spongepowered.asm.mixin.Unique;
import org.spongepowered.asm.mixin.injection.At;
import org.spongepowered.asm.mixin.injection.Inject;
import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;

import io.github.daomephsta.OriginAware;
import net.fabricmc.fabric.api.transfer.v1.transaction.Transaction;

@Mixin(targets = "net/fabricmc/fabric/impl/transfer/transaction/TransactionManagerImpl$TransactionImpl")
public abstract class TransactionOriginTracer implements Transaction, OriginAware
{
    @Unique
    private @Final List<StackFrame> silverfish_origin;

    @Inject(method = "<init>", at = @At("TAIL"))
    private void silverfish_traceOrigin(CallbackInfo info)
    {
        silverfish_origin = StackWalker.getInstance(Option.RETAIN_CLASS_REFERENCE)
            .walk(this::silverfish_originWalker);
    }

    private List<StackFrame> silverfish_originWalker(Stream<StackFrame> trace)
    {
        return trace
            // Trim the head until it's the frame calling the constructor
            .dropWhile(this::silverfish_trimHead)
            .toList();
    }

    private boolean silverfish_trimHead(StackFrame frame)
    {
        return frame.getMethodName().contains("silverfish_traceOrigin") ||
            frame.getMethodName().equals("<init>") &&
            // Check the constructor is declared by the target or a supertype
            frame.getDeclaringClass().isAssignableFrom(getClass());
    }

    @Override
    public List<StackFrame> silverfish_getOrigin()
    {
        return silverfish_origin;
    }
}