[DRAFT] Expose AssumeUTXO Load Snapshot Functionality To The GUI

[D33r-Gee]

based on the QML PR 424. For evaluation purposes only!

GUI Integration for UTXO Snapshot Loading

Overview

This PR adds initial GUI support for loading a UTXO snapshot, building on Bitcoin Core's assumeutxo infrastructure.

What This PR Does

1. Adds a basic GUI interface for loading UTXO snapshots via the Options Dialog panel
2. Provides visual confirmation of snapshot activation
3. Adds a snapshot progress notification bar accessible via a handler

Implementation Details

Core Components Modified

1. Node Interface (src/node/interfaces.cpp)

• Implements snapshotLoad() based on the loadtxoutset RPC

2. QT Integration (src/qt/optionsdialog.cpp)

• Manages snapshot loading state and progress
• makes use of a worker class to manage snapshot metadata (src/qt/snapshotmodel.cpp)
• Provides progress updates via a progress bar

Key Design Decisions

2. Extensibility

• Interface designed to accommodate future assumeutxo changes
• Error handling framework in place

Testing Instructions

1. Build
2. Launch Bitcoin Core GUI (bitcoin-qt)
3. Navigate to Settings -> Options
4. Click Load Snapshot button
5. Follow pop-up instructions
6. Test with sample snapshot:

https://bitcoin-snapshots.jaonoctus.dev/ (No affiliation with the maintainer of this site. As always "Don't trust! Verify!")

POC Ubuntu Screenshots `signet`

Launch bitcoin-qt on signet

Navigate to Settings -> Options

Click the "Load Snapshot..." button

Navigate to where your snapshot file is. The snapshot was downloaded from here

Click "Yes"

Wait for the snapshot to load and for this pop-up to appear and click "Ok"

Verify the "chain_snapshot" directory is present in your datadir

Expected Behavior

• File selection dialog works
• Success/failure state properly displayed
• Node becomes usable while background validation continues

Notes for Reviewers

• This is a POC so all feedback is welcomed
• I am not a designer so please feel free to chime in if there's a more elegant way to achieve this

This is a work in progress - feedback welcome on the approach and implementation details.

[DrahtBot]

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Reviews

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Type	Reviewers
Concept ACK	Sjors

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[D33r-Gee]

friendly ping @Sjors

[Sjors]

Concept ACK

Although I'm not sure how much effort we should put into maintaining the current GUI codebase (if it's going to be replaced with QML eventually), this particular feature is high on my wish list. And the code changes here seem very simple. So I'm happy to test and review it.

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The first commit which touches the node interface should eventually be PR'd to bitcoin/bitcoin. But let's wait with that until this PR has enough concept ACK and some initial review.