Module solana_runtime::bank

The bank module tracks client accounts and the progress of on-chain programs.

A single bank relates to a block produced by a single leader and each bank except for the genesis bank points back to a parent bank.

The bank is the main entrypoint for processing verified transactions with the function Bank::process_transactions

It does this by loading the accounts using the reference it holds on the account store, and then passing those to an InvokeContext which handles loading the programs specified by the Transaction and executing it.

The bank then stores the results to the accounts store.

It then has APIs for retrieving if a transaction has been processed and it’s status. See get_signature_status et al.

Bank lifecycle:

A bank is newly created and open to transactions. Transactions are applied until either the bank reached the tick count when the node is the leader for that slot, or the node has applied all transactions present in all Entrys in the slot.

Once it is complete, the bank can then be frozen. After frozen, no more transactions can be applied or state changes made. At the frozen step, rent will be applied and various sysvar special accounts update to the new state of the system.

After frozen, and the bank has had the appropriate number of votes on it, then it can become rooted. At this point, it will not be able to be removed from the chain and the state is finalized.

It offers a high-level API that signs transactions on behalf of the caller, and a low-level API for when they have already been signed and verified.

Modules

• test_utils
  utility function used for testing and benchmarking.

Structs

• Bank
  Manager for the state of all accounts and programs after processing its entries. AbiExample is needed even without Serialize/Deserialize; actual (de-)serialization are implemented elsewhere for versioning
• BankFieldsToDeserialize
• BankRc
• BankTestConfig
• CommitTransactionCounts
• InnerInstruction
• LoadAndExecuteTransactionsOutput
• NewBankOptions
• NonceFull
  Holds fee subtracted nonce info
• NoncePartial
  Holds limited nonce info available during transaction checks
• OptionalDropCallback
• RewardInfo
• SquashTiming
• TotalAccountsStats
  Struct to collect stats when scanning all accounts in get_total_accounts_stats()
• TransactionBalancesSet
• TransactionExecutionDetails
• TransactionLogCollector
• TransactionLogCollectorConfig
• TransactionLogInfo
• TransactionResults
• TransactionSimulationResult

Enums

• DurableNonceFee
• RewardCalculationEvent
• RewardType
• TransactionExecutionResult
  Type safe representation of a transaction execution attempt which differentiates between a transaction that was executed (will be committed to the ledger) and a transaction which wasn’t executed and will be dropped.
• TransactionLogCollectorFilter

Constants

• MAX_LEADER_SCHEDULE_STAKES
• SECONDS_PER_YEAR

Traits

• DropCallback
• NonceInfo
• RewardCalcTracer
  type alias is not supported for trait in rust yet. As a workaround, we define the RewardCalcTracer trait explicitly and implement it on any type that implement Fn(&RewardCalculationEvent) + Send + Sync.

Functions

• inner_instructions_list_from_instruction_trace
  Extract the InnerInstructionsList from a TransactionContext

Type Aliases

• BankSlotDelta
• BankStatusCache
• InnerInstructions
  An ordered list of compiled instructions that were invoked during a transaction instruction
• InnerInstructionsList
  A list of compiled instructions that were invoked during each instruction of a transaction
• TransactionBalances
• TransactionCheckResult
• TransactionLogMessages
  A list of log messages emitted during a transaction