Raft state machine for managing a replicated atomizer. More...

#include <state_machine.hpp>

Inheritance diagram for cbdc::atomizer::state_machine:

Collaboration diagram for cbdc::atomizer::state_machine:

Data Structures
struct	snapshot
	Represents a snapshot of the state machine with associated metadata. More...

Public Types
using	request
	Atomizer state machine request.

using	response = std::variant<make_block_response, get_block_response, errors>
	Atomizer state machine response.

using	blockstore_t = std::unordered_map<uint64_t, cbdc::atomizer::block>
	Maps block heights to blocks.

Public Member Functions
	state_machine (size_t stxo_cache_depth, std::string snapshot_dir)
	Constructor.

auto	commit (nuraft::ulong log_idx, nuraft::buffer &data) -> nuraft::ptr< nuraft::buffer > override
	Executes the committed the raft log entry at the given index and return the state machine execution result.

void	commit_config (nuraft::ulong log_idx, nuraft::ptr< nuraft::cluster_config > &) override
	Handler for the raft cluster configuration changes.

auto	read_logical_snp_obj (nuraft::snapshot &s, void *&user_snp_ctx, nuraft::ulong obj_id, nuraft::ptr< nuraft::buffer > &data_out, bool &is_last_obj) -> int override
	Read the portion of the state machine snapshot associated with the given metadata and object ID into a buffer.

void	save_logical_snp_obj (nuraft::snapshot &s, nuraft::ulong &obj_id, nuraft::buffer &data, bool is_first_obj, bool is_last_obj) override
	Saves the portion of the state machine snapshot associated with the given metadata and object ID into persistent storage.

auto	apply_snapshot (nuraft::snapshot &s) -> bool override
	Replaces the state of the state machine with the state stored in the snapshot referenced by the given snapshot metadata.

auto	last_snapshot () -> nuraft::ptr< nuraft::snapshot > override
	Returns the most recent snapshot metadata.

auto	last_commit_index () -> nuraft::ulong override
	Returns the index of the most recently committed log entry.

void	create_snapshot (nuraft::snapshot &s, nuraft::async_result< bool >::handler_type &when_done) override
	Creates a snapshot with the given metadata.

auto	tx_notify_count () -> uint64_t
	Returns the total number of transaction notifications which the state machine has processed.

Detailed Description

Raft state machine for managing a replicated atomizer.

Contains a atomizer and a cache of recently created blocks. Accepts requests to retrieve and prune recent blocks from the cache.

Definition at line 20 of file uhs/atomizer/atomizer/state_machine.hpp.

Member Typedef Documentation

◆ blockstore_t

using cbdc::atomizer::state_machine::blockstore_t = std::unordered_map<uint64_t, cbdc::atomizer::block>

Maps block heights to blocks.

Definition at line 117 of file uhs/atomizer/atomizer/state_machine.hpp.

◆ request

using cbdc::atomizer::state_machine::request

Initial value:

 std::variant<aggregate_tx_notify_request,
                                     make_block_request,
                                     get_block_request,
                                     prune_request>

Atomizer state machine request.

Definition at line 30 of file uhs/atomizer/atomizer/state_machine.hpp.

◆ response

using cbdc::atomizer::state_machine::response = std::variant<make_block_response, get_block_response, errors>

Atomizer state machine response.

Definition at line 36 of file uhs/atomizer/atomizer/state_machine.hpp.

Constructor & Destructor Documentation

◆ state_machine()

cbdc::atomizer::state_machine::state_machine	(	size_t	stxo_cache_depth,
		std::string	snapshot_dir )

Constructor.

Parameters

stxo_cache_depth	depth of the spent transaction output cache, passed to the atomizer.
snapshot_dir	path to directory in which to store snapshots. Will create the directory if it doesn't exist.

Definition at line 23 of file uhs/atomizer/atomizer/state_machine.cpp.

References apply_snapshot(), and last_snapshot().

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Member Function Documentation

◆ apply_snapshot()

auto cbdc::atomizer::state_machine::apply_snapshot ( nuraft::snapshot & s ) -> bool

nodiscardoverride

Replaces the state of the state machine with the state stored in the snapshot referenced by the given snapshot metadata.

Parameters

s	snapshot metadata.

Returns: true if the operation successfully applied the snapshot.

Definition at line 189 of file uhs/atomizer/atomizer/state_machine.cpp.

Referenced by state_machine().

◆ commit()

auto cbdc::atomizer::state_machine::commit	(	nuraft::ulong	log_idx,
		nuraft::buffer &	data ) -> nuraft::ptr<nuraft::buffer>

nodiscardoverride

Executes the committed the raft log entry at the given index and return the state machine execution result.

Parameters

log_idx	index of the given log entry.
data	serialized log entry containing state machine command and parameters.

Returns: serialized execution result.

Definition at line 42 of file uhs/atomizer/atomizer/state_machine.cpp.

References cbdc::from_buffer(), and cbdc::make_buffer().

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◆ commit_config()

void cbdc::atomizer::state_machine::commit_config	(	nuraft::ulong	log_idx,
		nuraft::ptr< nuraft::cluster_config > &	)

override

Handler for the raft cluster configuration changes.

Parameters

log_idx Raft log number of the configuration change.

Definition at line 103 of file uhs/atomizer/atomizer/state_machine.cpp.

◆ create_snapshot()

void cbdc::atomizer::state_machine::create_snapshot	(	nuraft::snapshot &	s,
		nuraft::async_result< bool >::handler_type &	when_done )

override

Creates a snapshot with the given metadata.

Parameters

s	snapshot metadata.
when_done	function to call when snapshot creation is complete.

Definition at line 211 of file uhs/atomizer/atomizer/state_machine.cpp.

References last_commit_index().

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◆ last_commit_index()

auto cbdc::atomizer::state_machine::last_commit_index ( ) -> nuraft::ulong

nodiscardoverride

Returns the index of the most recently committed log entry.

Returns: log index.

Definition at line 207 of file uhs/atomizer/atomizer/state_machine.cpp.

Referenced by create_snapshot().

◆ last_snapshot()

auto cbdc::atomizer::state_machine::last_snapshot ( ) -> nuraft::ptr<nuraft::snapshot>

nodiscardoverride

Returns the most recent snapshot metadata.

Returns: snapshot metadata, or nullptr if there is no snapshot.

Definition at line 199 of file uhs/atomizer/atomizer/state_machine.cpp.

Referenced by state_machine().

◆ read_logical_snp_obj()

auto cbdc::atomizer::state_machine::read_logical_snp_obj	(	nuraft::snapshot &	s,
		void *&	user_snp_ctx,
		nuraft::ulong	obj_id,
		nuraft::ptr< nuraft::buffer > &	data_out,
		bool &	is_last_obj ) -> int

nodiscardoverride

Read the portion of the state machine snapshot associated with the given metadata and object ID into a buffer.

Parameters

s	metadata of snapshot to read.
user_snp_ctx	pointer to a snapshot context; must be provided to all successive calls to this method for the same snapshot.
obj_id	ID of the snapshot object to read.
data_out	buffer in which to write the snapshot object.
is_last_obj	set to true if this object ID is the last snapshot object.

Returns: 0 if the object was read successfully.

Definition at line 111 of file uhs/atomizer/atomizer/state_machine.cpp.

◆ save_logical_snp_obj()

void cbdc::atomizer::state_machine::save_logical_snp_obj	(	nuraft::snapshot &	s,
		nuraft::ulong &	obj_id,
		nuraft::buffer &	data,
		bool	is_first_obj,
		bool	is_last_obj )

override

Saves the portion of the state machine snapshot associated with the given metadata and object ID into persistent storage.

Parameters

s	metadata of snapshot to save.
obj_id	ID of the snapshot object to save.
data	buffer from which to read the snapshot object data to save.
is_first_obj	true if this object ID is the first snapshot object.
is_last_obj	true if this object ID is the last snapshot object.

Definition at line 150 of file uhs/atomizer/atomizer/state_machine.cpp.

◆ tx_notify_count()

auto cbdc::atomizer::state_machine::tx_notify_count ( ) -> uint64_t

nodiscard

Returns the total number of transaction notifications which the state machine has processed.

Returns: transaction notification count.

Definition at line 266 of file uhs/atomizer/atomizer/state_machine.cpp.

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

Data Structures

Public Types

Public Member Functions

Detailed Description

Member Typedef Documentation

◆ blockstore_t

◆ request

◆ response

Constructor & Destructor Documentation

◆ state_machine()

Member Function Documentation

◆ apply_snapshot()

◆ commit()

◆ commit_config()

◆ create_snapshot()

◆ last_commit_index()

◆ last_snapshot()

◆ read_logical_snp_obj()

◆ save_logical_snp_obj()

◆ tx_notify_count()