ftl

Documentation

Index

• Constants
• Variables
• type ConfigType
• type ConfigValue
  • func Config[T ConfigType](name string) ConfigValue[T]
  • func (c ConfigValue[T]) Get(ctx context.Context) (out T)
  • func (c ConfigValue[T]) GoString() string
  • func (c ConfigValue[T]) String() string
• type Database
  • func PostgresDatabase(name string) Database
  • func (d Database) Get(ctx context.Context) *sql.DB
  • func (d Database) String() string
• type Empty
• type Handle
• type LeaseHandle
  • func Lease(ctx context.Context, ttl time.Duration, key ...string) (LeaseHandle, error)
  • func (l LeaseHandle) Err() error
  • func (l LeaseHandle) Release() error
• type Logger
  • func LoggerFromContext(ctx context.Context) *Logger
• type MapHandle
  • func Map[T, U any](getter Handle[T], fn func(context.Context, T) (U, error)) *MapHandle[T, U]
  • func (mh *MapHandle[T, U]) Get(ctx context.Context) U
• type Option
  • func Nil[T any](ptr T) Option[T]
  • func None[T any]() Option[T]
  • func Ptr[T any](ptr *T) Option[T]
  • func Some[T any](value T) Option[T]
  • func Zero[T any](value T) Option[T]
  • func (o Option[T]) Default(value T) T
  • func (o Option[T]) Get() (T, bool)
  • func (o Option[T]) GoString() string
  • func (o Option[T]) Marshal(w *bytes.Buffer, encode func(v reflect.Value, w *bytes.Buffer) error) error
  • func (o Option[T]) MarshalJSON() ([]byte, error)
  • func (o Option[T]) MustGet() T
  • func (o Option[T]) Ok() bool
  • func (o Option[T]) Ptr() *T
  • func (o *Option[T]) Scan(src any) error
  • func (o Option[T]) String() string
  • func (o *Option[T]) Unmarshal(d *json.Decoder, isNull bool, ...) error
  • func (o *Option[T]) UnmarshalJSON(data []byte) error
  • func (o Option[T]) Value() (driver.Value, error)
• type SecretType
• type SecretValue
  • func Secret[T SecretType](name string) SecretValue[T]
  • func (s SecretValue[T]) Get(ctx context.Context) (out T)
  • func (s SecretValue[T]) GoString() string
  • func (s SecretValue[T]) String() string
• type Sink
• type Source
• type SubscriptionHandle
  • func Subscription[E any](topic TopicHandle[E], name string) SubscriptionHandle[E]
• type TopicHandle
  • func Topic[E any](name string) TopicHandle[E]
  • func (t TopicHandle[E]) Publish(ctx context.Context, event E) error
• type Unit
• type Verb

Constants

const (
	Trace   = log.Trace
	Debug   = log.Debug
	Info    = log.Info
	Warn    = log.Warn
	Error   = log.Error
	Default = log.Default
)

Log levels.

Variables

var ErrLeaseHeld = fmt.Errorf("lease already held")

ErrLeaseHeld is returned when an attempt is made to acquire a lease that is already held.

Types

type ConfigType

type ConfigType interface{ any }

ConfigType is a type that can be used as a configuration value.

type ConfigValue

type ConfigValue[T ConfigType] struct {
	reflection.Ref
}

ConfigValue is a typed configuration key for the current module.

func Config

func Config[T ConfigType](name string) ConfigValue[T]

Config declares a typed configuration key for the current module.

func (ConfigValue[T]) Get

func (c ConfigValue[T]) Get(ctx context.Context) (out T)

Get returns the value of the configuration key from FTL.

func (ConfigValue[T]) GoString

func (c ConfigValue[T]) GoString() string

func (ConfigValue[T]) String

func (c ConfigValue[T]) String() string

type Database

type Database struct {
	Name   string
	DBType modulecontext.DBType
	// contains filtered or unexported fields
}

func PostgresDatabase

func PostgresDatabase(name string) Database

PostgresDatabase returns a handler for the named database.

func (Database) Get

func (d Database) Get(ctx context.Context) *sql.DB

Get returns the SQL DB connection for the database.

func (Database) String

func (d Database) String() string

type Empty

type Empty func(context.Context) error

An Empty is a function that does not accept input or return output.

type Handle

type Handle[T any] interface {
	Get(ctx context.Context) T
}

Handle represents a resource that can be retrieved such as a database connection, secret, etc.

type LeaseHandle

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

func Lease

func Lease(ctx context.Context, ttl time.Duration, key ...string) (LeaseHandle, error)

Lease acquires a new exclusive lease on a resource uniquely identified by [key].

The [ttl] defines the time after which the lease will be released if no heartbeat has been received. It must be >= 5s.

Each [key] is scoped to the module that acquires the lease.

Returns ErrLeaseHeld if the lease is already held.

func (LeaseHandle) Err

func (l LeaseHandle) Err() error

Err returns an error if the lease heartbeat fails.

func (LeaseHandle) Release

func (l LeaseHandle) Release() error

Release attempts to release the lease.

Will return an error if the heartbeat failed. In this situation there are no guarantees that the lease was held to completion.

type Logger

type Logger = log.Logger

Logger is a levelled printf-style logger with support for structured attributes.

func LoggerFromContext

func LoggerFromContext(ctx context.Context) *Logger

LoggerFromContext retrieves the current logger from the Context.

type MapHandle

type MapHandle[T, U any] struct {
	// contains filtered or unexported fields
}

func Map

func Map[T, U any](getter Handle[T], fn func(context.Context, T) (U, error)) *MapHandle[T, U]

Map an FTL resource type to a new type.

func (*MapHandle[T, U]) Get

func (mh *MapHandle[T, U]) Get(ctx context.Context) U

Get the mapped value.

type Option

type Option[T any] struct {
	// contains filtered or unexported fields
}

An Option type is a type that can contain a value or nothing.

func Nil

func Nil[T any](ptr T) Option[T]

Nil returns an Option that is invalid if the value is nil, otherwise the value.

If the type is not nillable (slice, map, chan, ptr, interface) this will panic.

func None

func None[T any]() Option[T]

None returns an Option that contains nothing.

func Ptr

func Ptr[T any](ptr *T) Option[T]

Ptr returns an Option that is invalid if the pointer is nil, otherwise the dereferenced pointer.

func Some

func Some[T any](value T) Option[T]

Some returns an Option that contains a value.

func Zero

func Zero[T any](value T) Option[T]

Zero returns an Option that is invalid if the value is the zero value, otherwise the value.

func (Option[T]) Default

func (o Option[T]) Default(value T) T

Default returns the Option value if it is present, otherwise it returns the value passed.

func (Option[T]) Get

func (o Option[T]) Get() (T, bool)

Get returns the value and a boolean indicating if the Option contains a value.

func (Option[T]) GoString

func (o Option[T]) GoString() string

func (Option[T]) Marshal

func (o Option[T]) Marshal(
	w *bytes.Buffer,
	encode func(v reflect.Value, w *bytes.Buffer) error,
) error

func (Option[T]) MarshalJSON

func (o Option[T]) MarshalJSON() ([]byte, error)

func (Option[T]) MustGet

func (o Option[T]) MustGet() T

MustGet returns the value. It panics if the Option contains nothing.

func (Option[T]) Ok

func (o Option[T]) Ok() bool

Ok returns true if the Option contains a value.

func (Option[T]) Ptr

func (o Option[T]) Ptr() *T

Ptr returns a pointer to the value if the Option contains a value, otherwise nil.

func (*Option[T]) Scan

func (o *Option[T]) Scan(src any) error

func (Option[T]) String

func (o Option[T]) String() string

func (*Option[T]) Unmarshal

func (o *Option[T]) Unmarshal(
	d *json.Decoder,
	isNull bool,
	decode func(d *json.Decoder, v reflect.Value) error,
) error

func (*Option[T]) UnmarshalJSON

func (o *Option[T]) UnmarshalJSON(data []byte) error

func (Option[T]) Value

func (o Option[T]) Value() (driver.Value, error)

type SecretType

type SecretType interface{ any }

SecretType is a type that can be used as a secret value.

type SecretValue

type SecretValue[T SecretType] struct {
	reflection.Ref
}

SecretValue is a typed secret for the current module.

func Secret

func Secret[T SecretType](name string) SecretValue[T]

Secret declares a typed secret for the current module.

func (SecretValue[T]) Get

func (s SecretValue[T]) Get(ctx context.Context) (out T)

Get returns the value of the secret from FTL.

func (SecretValue[T]) GoString

func (s SecretValue[T]) GoString() string

func (SecretValue[T]) String

func (s SecretValue[T]) String() string

type Sink

type Sink[Req any] func(context.Context, Req) error

A Sink is a function that accepts input but returns nothing.

type Source

type Source[Resp any] func(context.Context) (Resp, error)

A Source is a function that does not accept input but returns output.

type SubscriptionHandle

type SubscriptionHandle[E any] struct {
	Topic *schema.Ref
	Name  string
}

func Subscription

func Subscription[E any](topic TopicHandle[E], name string) SubscriptionHandle[E]

Subscription declares a subscription to a topic

Sinks can consume events from the subscription by including a "ftl:subscibe <subscription_name>" directive

type TopicHandle

type TopicHandle[E any] struct {
	Ref *schema.Ref
}

func Topic

func Topic[E any](name string) TopicHandle[E]

Topic declares a topic

Topics publish events, and subscriptions can listen to them.

func (TopicHandle[E]) Publish

func (t TopicHandle[E]) Publish(ctx context.Context, event E) error

Publish publishes an event to a topic

type Unit

type Unit struct{}

Unit is a type that has no value.

It can be used as a parameter or return value to indicate that a function does not accept or return any value.

type Verb

type Verb[Req, Resp any] func(context.Context, Req) (Resp, error)

A Verb is a function that accepts input and returns output.