#include <note_hash_tree_check.hpp>

Inheritance diagram for bb::avm2::simulation::NoteHashTreeCheck:

Public Member Functions
	NoteHashTreeCheck (const FF &first_nullifier, Poseidon2Interface &poseidon2, MerkleCheckInterface &merkle_check, EventEmitterInterface< NoteHashTreeCheckEvent > &event_emitter)

FF	get_first_nullifier () const override

bool	note_hash_exists (const FF &unique_note_hash, const FF &leaf_value, uint64_t leaf_index, std::span< const FF > sibling_path, const AppendOnlyTreeSnapshot &snapshot) override
	Checks whether a note hash exists in the note hash tree via Merkle membership proof.

AppendOnlyTreeSnapshot	append_note_hash (const FF &note_hash, AztecAddress contract_address, uint64_t note_hash_counter, std::span< const FF > sibling_path, const AppendOnlyTreeSnapshot &prev_snapshot) override
	Appends a raw (inner) note hash to the tree after siloing and making it unique.

AppendOnlyTreeSnapshot	append_siloed_note_hash (const FF &siloed_note_hash, uint64_t note_hash_counter, std::span< const FF > sibling_path, const AppendOnlyTreeSnapshot &prev_snapshot) override
	Appends a pre-siloed note hash to the tree after making it unique.

AppendOnlyTreeSnapshot	append_unique_note_hash (const FF &unique_note_hash, uint64_t note_hash_counter, std::span< const FF > sibling_path, const AppendOnlyTreeSnapshot &prev_snapshot) override
	Appends a pre-computed unique note hash directly to the tree.

void	on_checkpoint_created () override
	Emits a checkpoint creation event for the note hash tree.

void	on_checkpoint_committed () override
	Emits a checkpoint commit event, finalizing pending note hash tree changes.

void	on_checkpoint_reverted () override
	Emits a checkpoint revert event, rolling back pending note hash tree changes.

Public Member Functions inherited from bb::avm2::simulation::NoteHashTreeCheckInterface
virtual	~NoteHashTreeCheckInterface ()=default

Public Member Functions inherited from bb::avm2::simulation::CheckpointNotifiable
virtual	~CheckpointNotifiable ()=default

Private Member Functions
FF	make_siloed (AztecAddress contract_address, const FF &note_hash) const
	Computes the siloed note hash by hashing the contract address with the note hash.

FF	make_nonce (uint64_t note_hash_counter) const
	Derives a nonce for a note hash from the transaction's first nullifier and the note hash counter.

FF	make_unique (const FF &siloed_note_hash, const FF &nonce) const
	Computes a unique note hash by combining a siloed note hash with its nonce.

AppendOnlyTreeSnapshot	append_note_hash_internal (FF note_hash, std::optional< AztecAddress > contract_address, bool should_make_unique, uint64_t note_hash_counter, std::span< const FF > sibling_path, const AppendOnlyTreeSnapshot &prev_snapshot)
	Internal implementation for all note hash append variants.

Private Attributes
FF	first_nullifier

EventEmitterInterface< NoteHashTreeCheckEvent > &	events

Poseidon2Interface &	poseidon2

MerkleCheckInterface &	merkle_check

Detailed Description

Definition at line 18 of file note_hash_tree_check.hpp.

Constructor & Destructor Documentation

◆ NoteHashTreeCheck()

bb::avm2::simulation::NoteHashTreeCheck::NoteHashTreeCheck	(	const FF &	first_nullifier,
		Poseidon2Interface &	poseidon2,
		MerkleCheckInterface &	merkle_check,
		EventEmitterInterface< NoteHashTreeCheckEvent > &	event_emitter
	)

inline

Definition at line 20 of file note_hash_tree_check.hpp.

Member Function Documentation

◆ append_note_hash()

AppendOnlyTreeSnapshot bb::avm2::simulation::NoteHashTreeCheck::append_note_hash	(	const FF &	note_hash,
		AztecAddress	contract_address,
		uint64_t	note_hash_counter,
		std::span< const FF >	sibling_path,
		const AppendOnlyTreeSnapshot &	prev_snapshot
	)

overridevirtual

Appends a raw (inner) note hash to the tree after siloing and making it unique.

This is the standard entry point for user-space note hash insertion. The note hash is first siloed with the contract address, then made unique using a nonce derived from the first nullifier and the note hash counter, before being inserted into the tree.

Parameters

note_hash	The raw (inner) note hash to append.
contract_address	The address of the contract that created the note.
note_hash_counter	A counter distinguishing this note hash within the transaction.
sibling_path	The Merkle sibling path for the append operation.
prev_snapshot	The tree snapshot before the append.

Returns: The updated tree snapshot after inserting the new leaf.

Implements bb::avm2::simulation::NoteHashTreeCheckInterface.

Definition at line 91 of file note_hash_tree_check.cpp.

◆ append_note_hash_internal()

AppendOnlyTreeSnapshot bb::avm2::simulation::NoteHashTreeCheck::append_note_hash_internal	(	FF	note_hash,
		std::optional< AztecAddress >	contract_address,
		bool	should_make_unique,
		uint64_t	note_hash_counter,
		std::span< const FF >	sibling_path,
		const AppendOnlyTreeSnapshot &	prev_snapshot
	)

private

Internal implementation for all note hash append variants.

Optionally silos and/or makes the note hash unique before inserting it as a new leaf at the next available index. Performs a Merkle write (replacing a zero leaf) and emits a read/write event capturing all intermediate data for constraint generation.

Parameters

note_hash	The note hash to insert (may be raw, siloed, or unique depending on caller).
contract_address	If present, the note hash is siloed with this address before insertion.
should_make_unique	If true, a nonce is derived and the note hash is made unique.
note_hash_counter	A counter distinguishing this note hash within the transaction.
sibling_path	The Merkle sibling path for the append operation.
prev_snapshot	The tree snapshot before the append.

Returns: The updated tree snapshot after inserting the new leaf.

Definition at line 166 of file note_hash_tree_check.cpp.

◆ append_siloed_note_hash()

AppendOnlyTreeSnapshot bb::avm2::simulation::NoteHashTreeCheck::append_siloed_note_hash	(	const FF &	siloed_note_hash,
		uint64_t	note_hash_counter,
		std::span< const FF >	sibling_path,
		const AppendOnlyTreeSnapshot &	prev_snapshot
	)

overridevirtual

Appends a pre-siloed note hash to the tree after making it unique.

Skips the siloing step (the note hash is already bound to a contract) but still derives a nonce and computes the unique note hash before insertion.

Parameters

siloed_note_hash	The already-siloed note hash to append.
note_hash_counter	A counter distinguishing this note hash within the transaction.
sibling_path	The Merkle sibling path for the append operation.
prev_snapshot	The tree snapshot before the append.

Returns: The updated tree snapshot after inserting the new leaf.

Implements bb::avm2::simulation::NoteHashTreeCheckInterface.

Definition at line 113 of file note_hash_tree_check.cpp.

◆ append_unique_note_hash()

AppendOnlyTreeSnapshot bb::avm2::simulation::NoteHashTreeCheck::append_unique_note_hash	(	const FF &	unique_note_hash,
		uint64_t	note_hash_counter,
		std::span< const FF >	sibling_path,
		const AppendOnlyTreeSnapshot &	prev_snapshot
	)

overridevirtual

Appends a pre-computed unique note hash directly to the tree.

Skips both siloing and uniqueness derivation – the note hash is inserted as-is. This is used when the caller has already performed all transformations externally.

Parameters

unique_note_hash	The fully-unique note hash to append.
note_hash_counter	A counter distinguishing this note hash within the transaction.
sibling_path	The Merkle sibling path for the append operation.
prev_snapshot	The tree snapshot before the append.

Returns: The updated tree snapshot after inserting the new leaf.

Implements bb::avm2::simulation::NoteHashTreeCheckInterface.

Definition at line 138 of file note_hash_tree_check.cpp.

◆ get_first_nullifier()

FF bb::avm2::simulation::NoteHashTreeCheck::get_first_nullifier ( ) const

inlineoverridevirtual

Implements bb::avm2::simulation::NoteHashTreeCheckInterface.

Definition at line 30 of file note_hash_tree_check.hpp.

◆ make_nonce()

FF bb::avm2::simulation::NoteHashTreeCheck::make_nonce ( uint64_t note_hash_counter ) const

private

Derives a nonce for a note hash from the transaction's first nullifier and the note hash counter.

The nonce ensures uniqueness of note hashes within and across transactions.

Parameters

note_hash_counter The index of the note hash in the transaction.

Returns: The nonce: Poseidon2(DOM_SEP__NOTE_HASH_NONCE, first_nullifier, note_hash_counter).

Definition at line 58 of file note_hash_tree_check.cpp.

◆ make_siloed()

FF bb::avm2::simulation::NoteHashTreeCheck::make_siloed	(	AztecAddress	contract_address,
		const FF &	note_hash
	)		const

private

Computes the siloed note hash by hashing the contract address with the note hash.

Siloing binds a note hash to its originating contract, preventing cross-contract collisions. Uses Poseidon2 with a domain separator for siloed note hashes.

Parameters

contract_address	The address of the contract that created the note.
note_hash	The original (inner) note hash.

Returns: The siloed note hash: Poseidon2(DOM_SEP__SILOED_NOTE_HASH, contract_address, note_hash).

Definition at line 45 of file note_hash_tree_check.cpp.

◆ make_unique()

FF bb::avm2::simulation::NoteHashTreeCheck::make_unique	(	const FF &	siloed_note_hash,
		const FF &	nonce
	)		const

private

Computes a unique note hash by combining a siloed note hash with its nonce.

This final transformation guarantees global uniqueness of the note hash.

Parameters

siloed_note_hash	The siloed note hash (already bound to a contract).
nonce	The nonce derived from the first nullifier and note hash counter.

Returns: The unique note hash: Poseidon2(DOM_SEP__UNIQUE_NOTE_HASH, nonce, siloed_note_hash).

Definition at line 72 of file note_hash_tree_check.cpp.

◆ note_hash_exists()

bool bb::avm2::simulation::NoteHashTreeCheck::note_hash_exists	(	const FF &	unique_note_hash,
		const FF &	leaf_value,
		uint64_t	leaf_index,
		std::span< const FF >	sibling_path,
		const AppendOnlyTreeSnapshot &	snapshot
	)

overridevirtual

Checks whether a note hash exists in the note hash tree via Merkle membership proof.

Verifies that leaf_value is present at leaf_index in the tree whose root is given by snapshot, then compares it against the claimed unique_note_hash.

Note: This function does not validate that leaf_index is within the bounds of the tree nor that it is less than the next available leaf index.

Parameters

unique_note_hash	The unique note hash the caller claims to exist.
leaf_value	The actual leaf value retrieved from the tree.
leaf_index	The index of the leaf in the tree.
sibling_path	The Merkle sibling path used for the membership proof.
snapshot	The tree snapshot (root + size) to verify against.

Returns: true if unique_note_hash equals leaf_value, false otherwise.

Implements bb::avm2::simulation::NoteHashTreeCheckInterface.

Definition at line 21 of file note_hash_tree_check.cpp.

◆ on_checkpoint_committed()

void bb::avm2::simulation::NoteHashTreeCheck::on_checkpoint_committed ( )

overridevirtual

Emits a checkpoint commit event, finalizing pending note hash tree changes.

Implements bb::avm2::simulation::CheckpointNotifiable.

Definition at line 214 of file note_hash_tree_check.cpp.

◆ on_checkpoint_created()

void bb::avm2::simulation::NoteHashTreeCheck::on_checkpoint_created ( )

overridevirtual

Emits a checkpoint creation event for the note hash tree.

Implements bb::avm2::simulation::CheckpointNotifiable.

Definition at line 208 of file note_hash_tree_check.cpp.

◆ on_checkpoint_reverted()

void bb::avm2::simulation::NoteHashTreeCheck::on_checkpoint_reverted ( )

overridevirtual

Emits a checkpoint revert event, rolling back pending note hash tree changes.

Implements bb::avm2::simulation::CheckpointNotifiable.

Definition at line 220 of file note_hash_tree_check.cpp.

Member Data Documentation

◆ events

EventEmitterInterface<NoteHashTreeCheckEvent>& bb::avm2::simulation::NoteHashTreeCheck::events

private

Definition at line 67 of file note_hash_tree_check.hpp.

◆ first_nullifier

FF bb::avm2::simulation::NoteHashTreeCheck::first_nullifier

private

Definition at line 66 of file note_hash_tree_check.hpp.

◆ merkle_check

MerkleCheckInterface& bb::avm2::simulation::NoteHashTreeCheck::merkle_check

private

Definition at line 69 of file note_hash_tree_check.hpp.

◆ poseidon2

Poseidon2Interface& bb::avm2::simulation::NoteHashTreeCheck::poseidon2

private

Definition at line 68 of file note_hash_tree_check.hpp.

The documentation for this class was generated from the following files:

src/barretenberg/vm2/simulation/gadgets/note_hash_tree_check.hpp
src/barretenberg/vm2/simulation/gadgets/note_hash_tree_check.cpp

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ NoteHashTreeCheck()

Member Function Documentation

◆ append_note_hash()

◆ append_note_hash_internal()

◆ append_siloed_note_hash()

◆ append_unique_note_hash()

◆ get_first_nullifier()

◆ make_nonce()

◆ make_siloed()

◆ make_unique()

◆ note_hash_exists()

◆ on_checkpoint_committed()

◆ on_checkpoint_created()

◆ on_checkpoint_reverted()

Member Data Documentation

◆ events

◆ first_nullifier

◆ merkle_check

◆ poseidon2