precompiles

Documentation

Overview

package actions allows custom actions to be registered with the engine.

Index

• func RegisterPrecompile(name string, ext Initializer) error
• func RegisteredPrecompiles() map[string]Initializer
• type DeploymentContext
• type Initializer
• type Instance
• type ProcedureContext
  • func (p *ProcedureContext) NewScope() *ProcedureContext
  • func (p *ProcedureContext) SetValue(key string, value any)
  • func (p *ProcedureContext) Values() map[string]any

Functions

func RegisterPrecompile

func RegisterPrecompile(name string, ext Initializer) error

RegisterPrecompile registers a precompile extension with the engine.

func RegisteredPrecompiles

func RegisteredPrecompiles() map[string]Initializer

Types

type DeploymentContext

type DeploymentContext struct {
	Ctx    context.Context
	Schema *types.Schema
}

DeploymentContext is the context for a dataset deployment transaction.

type Initializer

type Initializer func(ctx *DeploymentContext, service *common.Service, metadata map[string]string) (Instance, error)

Initializer initializes a new instance of a precompile. It is called when a Kuneiform schema is deployed that calls "use <precompile> {key: "value"} as <name>". It is also called when the node starts up, if a database is already deployed that uses the precompile. The key/value pairs are passed as the metadata parameter. When initialize is called, the dataset is not yet accessible.

type Instance

type Instance interface {
	// Call executes the requested method of the precompile. It is up
	// to the instance implementation to determine if a method is
	// valid, and to subsequently decode the arguments. The arguments
	// passed in as args, as well as returned, are scalar values.
	Call(scoper *ProcedureContext, app *common.App, method string, inputs []any) ([]any, error)
}

Instance is a named initialized instance of a precompile. It is returned from the precompile initialization, as specified by the Initializer. It will exist for the lifetime of the deployed dataset, and a single dataset can have multiple instances of the same precompile.

type ProcedureContext

type ProcedureContext struct {
	// TxCtx is the transaction context of the current execution.
	TxCtx *common.TxContext

	// DBID is the database identifier for the current scope.
	// if calling a precompile instance instead of a procedure, it
	// will be the last used DBID.
	DBID string

	// Procedure is the Procedure identifier for the current scope.
	// if calling a precompile instance instead of a Procedure, it
	// will be the last used Procedure.
	Procedure string
	// Result is the result of the most recent SQL query.
	Result *sql.ResultSet

	// StackDepth tracks the current depth of the procedure call stack. It is
	// incremented each time a procedure calls another procedure.
	StackDepth int
	// UsedGas is the amount of gas used in the current execution.
	UsedGas uint64
	// contains filtered or unexported fields
}

ProcedureContext is the context for a procedure and action execution.

func (*ProcedureContext) NewScope

func (p *ProcedureContext) NewScope() *ProcedureContext

NewScope creates a new procedure context for a child procedure. It will not inherit the values or last result from the parent. It will inherit the dbid, procedure, and stack depth from the parent.

func (*ProcedureContext) SetValue

func (p *ProcedureContext) SetValue(key string, value any)

SetValue sets a value in the scope. Values are case-insensitive. If a value for the key already exists, it will be overwritten.

func (*ProcedureContext) Values

func (p *ProcedureContext) Values() map[string]any

Values copies the values from the scope into a map. It will also include contextual variables, such as the caller. If a context variable has the same name as a scope variable, the scope variable will be overwritten.