transform

package
v1.6.1 Latest Latest
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Published: Jul 26, 2019 License: Apache-2.0 Imports: 10 Imported by: 44

Documentation

Overview

Package transform provides transforms on commands.

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

This section is empty.

Types

type CmdAndID added in v1.2.0

type CmdAndID struct {
	Cmd api.Cmd
	ID  api.CmdID
}

CmdAndID is a pair of api.Cmd and api.CmdID

type CmdAndIDList added in v1.2.0

type CmdAndIDList []CmdAndID

CmdAndIDList is a list of CmdAndIDs.

func NewCmdAndIDList added in v1.2.0

func NewCmdAndIDList(cmds ...interface{}) CmdAndIDList

NewCmdAndIDList takes a mix of CmdWithIDs and Cmds with an ID property and returns a CmdAndIDList. Cmds that have an ID property are transformed into CmdAndID by using the ID.

func (*CmdAndIDList) Write added in v1.2.0

func (l *CmdAndIDList) Write(ctx context.Context, id api.CmdID, c api.Cmd)

type CmdWithID added in v1.2.0

type CmdWithID interface {
	api.Cmd
	ID() api.CmdID
}

CmdWithID is a api.Cmd that embeds its own ID.

type Injector

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

Injector is an implementation of Transformer that can inject commands into the stream.

func (*Injector) Flush

func (t *Injector) Flush(ctx context.Context, out Writer)

Flush implements the Transformer interface.

func (*Injector) Inject

func (t *Injector) Inject(after api.CmdID, cmd api.Cmd)

Inject emits cmd after the command with identifier after.

func (*Injector) Transform

func (t *Injector) Transform(ctx context.Context, id api.CmdID, cmd api.Cmd, out Writer)

Transform implements the Transformer interface.

type Recorder added in v1.2.0

type Recorder struct {
	S          *api.GlobalState
	Cmds       []api.Cmd
	CmdsAndIDs []CmdAndID
}

Recorder is a Writer that record all commands that pass through it.

func (*Recorder) MutateAndWrite added in v1.2.0

func (r *Recorder) MutateAndWrite(ctx context.Context, id api.CmdID, cmd api.Cmd)

MutateAndWrite records the command and id into the Cmds and CmdsAndIDs lists and if the Recorder has a state, mutates this state object.

func (*Recorder) State added in v1.2.0

func (r *Recorder) State() *api.GlobalState

State returns the state object associated with this writer.

type Tasks added in v0.6.1

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

Tasks is a Transformer that calls functions when the specified command is reached or passed.

func (*Tasks) Add added in v0.6.1

func (t *Tasks) Add(at api.CmdID, work func(context.Context, Writer))

Add adds the job to be invoked when the command with the specified id is reached or passed.

func (*Tasks) Flush added in v0.6.1

func (t *Tasks) Flush(ctx context.Context, out Writer)

func (*Tasks) Transform added in v0.6.1

func (t *Tasks) Transform(ctx context.Context, id api.CmdID, cmd api.Cmd, out Writer)

type Terminator

type Terminator interface {
	Transformer

	// Add relaxes the termination limit to pass-through all commands before and
	// including the command or subcommand.
	Add(context.Context, int, api.CmdID, api.SubCmdIdx) error
}

Terminator is an Transformer that prevents commands passing-through it after a certain point in the stream.

func NewEarlyTerminator

func NewEarlyTerminator(api api.ID) Terminator

NewEarlyTerminator returns a Terminator that will consume all commands of the given API type that come after the last command passed to Add.

type TransformWriter

type TransformWriter struct {
	S *api.GlobalState
	T Transformer
	O Writer
}

TransformWriter implements the Writer interface, transforming each command that is written with T, before writing the result to O.

func (TransformWriter) MutateAndWrite

func (p TransformWriter) MutateAndWrite(ctx context.Context, id api.CmdID, cmd api.Cmd)

func (TransformWriter) State

func (p TransformWriter) State() *api.GlobalState

type Transformer

type Transformer interface {
	// Transform takes a given command and identifier and Writes out a possibly
	// transformed set of commands to the output.
	// Transform must not modify cmd in any way.
	Transform(ctx context.Context, id api.CmdID, cmd api.Cmd, output Writer)
	// Flush is called at the end of a command stream to cause Transformers
	// that cache commands to send any they have stored into the output.
	Flush(ctx context.Context, output Writer)
}

Transformer is the interface that wraps the basic Transform method.

func NewCaptureLog added in v1.2.0

func NewCaptureLog(ctx context.Context, sourceCapture *capture.GraphicsCapture, path string) Transformer

NewCaptureLog returns a Transformer that will log all commands passed through it to the capture file at path.

func NewFileLog

func NewFileLog(ctx context.Context, path string) Transformer

NewFileLog returns a Transformer that will log all commands passed through it to the text file at path.

func Transform

func Transform(name string, f func(ctx context.Context, id api.CmdID, cmd api.Cmd, output Writer)) Transformer

Transform is a helper for building simple Transformers that are implemented by function f. name is used to identify the transform when logging.

type Transforms

type Transforms []Transformer

Transforms is a list of Transformer objects.

func (*Transforms) Add

func (l *Transforms) Add(t ...Transformer)

Add is a convenience function for appending the list of Transformers t to the end of the Transforms list, after filtering out nil Transformers.

func (*Transforms) Prepend

func (l *Transforms) Prepend(t Transformer)

Prepend adds the given transformer to the beginning of the transform chain.

func (Transforms) Transform

func (l Transforms) Transform(ctx context.Context, cmds []api.Cmd, out Writer)

Transform sequentially transforms the commands by each of the transformers in the list, before writing the final output to the output command Writer.

type Writer

type Writer interface {
	// State returns the state object associated with this writer.
	State() *api.GlobalState
	// MutateAndWrite mutates the state object associated with this writer,
	// and it passes the command to further consumers.
	MutateAndWrite(ctx context.Context, id api.CmdID, cmd api.Cmd)
}

Writer is the interface which consumes the output of an Transformer. It also keeps track of state changes caused by all commands written to it. Conceptually, each Writer object contains its own separate State object, which is modified when MutateAndWrite is called. This allows the transform to access the state both before and after the mutation of state happens. It is also possible to omit/insert commands. In practice, single state object can be shared by all transforms for performance (i.e. the mutation is done only once at the very end). This potentially allows state changes to leak upstream so care is needed. There is a configuration flag to switch between the shared/separate modes.

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