consul/vendor/github.com/Azure/go-ansiterm/parser.go

137 lines
3.2 KiB
Go

package ansiterm
import (
"errors"
"io/ioutil"
"os"
"github.com/sirupsen/logrus"
)
var logger *logrus.Logger
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
}
func CreateParser(initialState string, evtHandler AnsiEventHandler) *AnsiParser {
logFile := ioutil.Discard
if isDebugEnv := os.Getenv(LogEnv); isDebugEnv == "1" {
logFile, _ = os.Create("ansiParser.log")
}
logger = &logrus.Logger{
Out: logFile,
Formatter: new(logrus.TextFormatter),
Level: logrus.InfoLevel,
}
parser := &AnsiParser{
eventHandler: evtHandler,
context: &ansiContext{},
}
parser.csiEntry = csiEntryState{baseState{name: "CsiEntry", parser: parser}}
parser.csiParam = csiParamState{baseState{name: "CsiParam", parser: parser}}
parser.dcsEntry = dcsEntryState{baseState{name: "DcsEntry", parser: parser}}
parser.escape = escapeState{baseState{name: "Escape", parser: parser}}
parser.escapeIntermediate = escapeIntermediateState{baseState{name: "EscapeIntermediate", parser: parser}}
parser.error = errorState{baseState{name: "Error", parser: parser}}
parser.ground = groundState{baseState{name: "Ground", parser: parser}}
parser.oscString = oscStringState{baseState{name: "OscString", parser: parser}}
parser.stateMap = []state{
parser.csiEntry,
parser.csiParam,
parser.dcsEntry,
parser.escape,
parser.escapeIntermediate,
parser.error,
parser.ground,
parser.oscString,
}
parser.currState = getState(initialState, parser.stateMap)
logger.Infof("CreateParser: parser %p", parser)
return parser
}
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 {
logger.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 {
logger.Infof("ChangeState %s --> %s", ap.currState.Name(), newState.Name())
// Exit old state
if err := ap.currState.Exit(); err != nil {
logger.Infof("Exit state '%s' failed with : '%v'", ap.currState.Name(), err)
return err
}
// Perform transition action
if err := ap.currState.Transition(newState); err != nil {
logger.Infof("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 {
logger.Infof("Enter state '%s' failed with: '%v'", newState.Name(), err)
return err
}
ap.currState = newState
return nil
}