traefik/vendor/github.com/Azure/go-ansiterm/parser.go
2017-10-31 10:42:03 +01:00

151 lines
3.4 KiB
Go

package ansiterm
import (
"errors"
"log"
"os"
)
type AnsiParser struct {
currState state
eventHandler AnsiEventHandler
context *ansiContext
csiEntry state
csiParam state
dcsEntry state
escape state
escapeIntermediate state
error state
ground state
oscString state
stateMap []state
logf func(string, ...interface{})
}
type Option func(*AnsiParser)
func WithLogf(f func(string, ...interface{})) Option {
return func(ap *AnsiParser) {
ap.logf = f
}
}
func CreateParser(initialState string, evtHandler AnsiEventHandler, opts ...Option) *AnsiParser {
ap := &AnsiParser{
eventHandler: evtHandler,
context: &ansiContext{},
}
for _, o := range opts {
o(ap)
}
if isDebugEnv := os.Getenv(LogEnv); isDebugEnv == "1" {
logFile, _ := os.Create("ansiParser.log")
logger := log.New(logFile, "", log.LstdFlags)
if ap.logf != nil {
l := ap.logf
ap.logf = func(s string, v ...interface{}) {
l(s, v...)
logger.Printf(s, v...)
}
} else {
ap.logf = logger.Printf
}
}
if ap.logf == nil {
ap.logf = func(string, ...interface{}) {}
}
ap.csiEntry = csiEntryState{baseState{name: "CsiEntry", parser: ap}}
ap.csiParam = csiParamState{baseState{name: "CsiParam", parser: ap}}
ap.dcsEntry = dcsEntryState{baseState{name: "DcsEntry", parser: ap}}
ap.escape = escapeState{baseState{name: "Escape", parser: ap}}
ap.escapeIntermediate = escapeIntermediateState{baseState{name: "EscapeIntermediate", parser: ap}}
ap.error = errorState{baseState{name: "Error", parser: ap}}
ap.ground = groundState{baseState{name: "Ground", parser: ap}}
ap.oscString = oscStringState{baseState{name: "OscString", parser: ap}}
ap.stateMap = []state{
ap.csiEntry,
ap.csiParam,
ap.dcsEntry,
ap.escape,
ap.escapeIntermediate,
ap.error,
ap.ground,
ap.oscString,
}
ap.currState = getState(initialState, ap.stateMap)
ap.logf("CreateParser: parser %p", ap)
return ap
}
func getState(name string, states []state) state {
for _, el := range states {
if el.Name() == name {
return el
}
}
return nil
}
func (ap *AnsiParser) Parse(bytes []byte) (int, error) {
for i, b := range bytes {
if err := ap.handle(b); err != nil {
return i, err
}
}
return len(bytes), ap.eventHandler.Flush()
}
func (ap *AnsiParser) handle(b byte) error {
ap.context.currentChar = b
newState, err := ap.currState.Handle(b)
if err != nil {
return err
}
if newState == nil {
ap.logf("WARNING: newState is nil")
return errors.New("New state of 'nil' is invalid.")
}
if newState != ap.currState {
if err := ap.changeState(newState); err != nil {
return err
}
}
return nil
}
func (ap *AnsiParser) changeState(newState state) error {
ap.logf("ChangeState %s --> %s", ap.currState.Name(), newState.Name())
// Exit old state
if err := ap.currState.Exit(); err != nil {
ap.logf("Exit state '%s' failed with : '%v'", ap.currState.Name(), err)
return err
}
// Perform transition action
if err := ap.currState.Transition(newState); err != nil {
ap.logf("Transition from '%s' to '%s' failed with: '%v'", ap.currState.Name(), newState.Name, err)
return err
}
// Enter new state
if err := newState.Enter(); err != nil {
ap.logf("Enter state '%s' failed with: '%v'", newState.Name(), err)
return err
}
ap.currState = newState
return nil
}