state

type EmptyStorageSnapshot struct{}

type ExecutionSnapshot struct {
	// Note that the ReadSet only include reads from the storage snapshot.
	// Reads from the WriteSet are excluded from the ReadSet.
	ReadSet map[flow.RegisterID]struct{}

	WriteSet map[flow.RegisterID]flow.RegisterValue

	// Note that the spock secret may be nil if the view does not support spock.
	SpockSecret []byte

	// Note that the meter may be nil if the view does not support metering.
	*meter.Meter
}

type ExecutionState struct {
	// contains filtered or unexported fields
}

type MapStorageSnapshot map[flow.RegisterID]flow.RegisterValue

type Meter interface {
	MeterComputation(kind common.ComputationKind, intensity uint) error
	ComputationIntensities() meter.MeteredComputationIntensities
	TotalComputationLimit() uint
	TotalComputationUsed() uint64

	MeterMemory(kind common.MemoryKind, intensity uint) error
	MemoryIntensities() meter.MeteredMemoryIntensities
	TotalMemoryEstimate() uint64

	InteractionUsed() uint64

	MeterEmittedEvent(byteSize uint64) error
	TotalEmittedEventBytes() uint64

	// RunWithAllLimitsDisabled runs f with limits disabled
	RunWithAllLimitsDisabled(f func())
}

type NestedTransaction interface {
	Meter

	// NumNestedTransactions returns the number of uncommitted nested
	// transactions.  Note that the main transaction is not considered a
	// nested transaction.
	NumNestedTransactions() int

	// IsParseRestricted returns true if the current nested transaction is in
	// parse resticted access mode.
	IsParseRestricted() bool

	MainTransactionId() NestedTransactionId

	// IsCurrent returns true if the provide id refers to the current (nested)
	// transaction.
	IsCurrent(id NestedTransactionId) bool

	// FinalizeMainTransaction finalizes the main transaction and returns
	// its execution snapshot.  The finalized main transaction will not accept
	// any new commits after this point.  This returns an error if there are
	// outstanding nested transactions.
	FinalizeMainTransaction() (*ExecutionSnapshot, error)

	// BeginNestedTransaction creates a unrestricted nested transaction within
	// the current unrestricted (nested) transaction.  The meter parameters are
	// inherited from the current transaction.  This returns error if the
	// current nested transaction is program restricted.
	BeginNestedTransaction() (
		NestedTransactionId,
		error,
	)

	// BeginNestedTransactionWithMeterParams creates a unrestricted nested
	// transaction within the current unrestricted (nested) transaction, using
	// the provided meter parameters. This returns error if the current nested
	// transaction is program restricted.
	BeginNestedTransactionWithMeterParams(
		params meter.MeterParameters,
	) (
		NestedTransactionId,
		error,
	)

	// BeginParseRestrictedNestedTransaction creates a restricted nested
	// transaction within the current (nested) transaction.  The meter
	// parameters are inherited from the current transaction.
	BeginParseRestrictedNestedTransaction(
		location common.AddressLocation,
	) (
		NestedTransactionId,
		error,
	)

	// CommitNestedTransaction commits the changes in the current unrestricted
	// nested transaction to the parent (nested) transaction.  This returns
	// error if the expectedId does not match the current nested transaction.
	// This returns the committed execution snapshot otherwise.
	//
	// Note: The returned committed execution snapshot may be reused by another
	// transaction via AttachAndCommitNestedTransaction to update the
	// transaction bookkeeping, but the caller must manually invalidate the
	// state.
	// USE WITH EXTREME CAUTION.
	CommitNestedTransaction(
		expectedId NestedTransactionId,
	) (
		*ExecutionSnapshot,
		error,
	)

	// CommitParseRestrictedNestedTransaction commits the changes in the
	// current restricted nested transaction to the parent (nested)
	// transaction.  This returns error if the specified location does not
	// match the tracked location. This returns the committed execution
	// snapshot otherwise.
	//
	// Note: The returned committed execution snapshot may be reused by another
	// transaction via AttachAndCommitNestedTransaction to update the
	// transaction bookkeeping, but the caller must manually invalidate the
	// state.
	// USE WITH EXTREME CAUTION.
	CommitParseRestrictedNestedTransaction(
		location common.AddressLocation,
	) (
		*ExecutionSnapshot,
		error,
	)

	// PauseNestedTransaction detaches the current nested transaction from the
	// parent transaction, and returns the paused nested transaction state.
	// The paused nested transaction may be resume via Resume.
	//
	// WARNING: Pause and Resume are intended for implementing continuation
	// passing style behavior for the transaction executor, with the assumption
	// that the states accessed prior to pausing remain valid after resumption.
	// The paused nested transaction should not be reused across transactions.
	// IT IS NOT SAFE TO PAUSE A NESTED TRANSACTION IN GENERAL SINCE THAT
	// COULD LEAD TO PHANTOM READS.
	PauseNestedTransaction(
		expectedId NestedTransactionId,
	) (
		*ExecutionState,
		error,
	)

	// ResumeNestedTransaction attaches the paused nested transaction (state)
	// to the current transaction.
	ResumeNestedTransaction(pausedState *ExecutionState)

	// AttachAndCommitNestedTransaction commits the changes from the cached
	// nested transaction execution snapshot to the current (nested)
	// transaction.
	AttachAndCommitNestedTransaction(cachedSnapshot *ExecutionSnapshot) error

	// RestartNestedTransaction merges all changes that belongs to the nested
	// transaction about to be restart (for spock/meter bookkeeping), then
	// wipes its view changes.
	RestartNestedTransaction(
		id NestedTransactionId,
	) error

	Get(id flow.RegisterID) (flow.RegisterValue, error)

	Set(id flow.RegisterID, value flow.RegisterValue) error

	ViewForTestingOnly() View
}

type NestedTransactionId struct {
	// contains filtered or unexported fields
}

type Peeker interface {
	Peek(id flow.RegisterID) (flow.RegisterValue, error)
}

type ReadFuncStorageSnapshot struct {
	ReadFunc func(flow.RegisterID) (flow.RegisterValue, error)
}

type StateParameters struct {
	meter.MeterParameters
	// contains filtered or unexported fields
}

type Storage interface {
	// TODO(patrick): remove once fvm.VM.Run() is deprecated
	Peek(id flow.RegisterID) (flow.RegisterValue, error)

	Set(id flow.RegisterID, value flow.RegisterValue) error
	Get(id flow.RegisterID) (flow.RegisterValue, error)

	DropChanges() error
}

type StorageSnapshot interface {
	// Get returns the register id's value, or an empty RegisterValue if the id
	// is not found.
	Get(id flow.RegisterID) (flow.RegisterValue, error)
}

type View interface {
	NewChild() View

	Finalize() *ExecutionSnapshot
	Merge(child *ExecutionSnapshot) error

	Storage
}