Refactor the code so that fzf can be used as a library (#3769)

src/core.go

@@ -2,7 +2,6 @@
 package fzf
 
 import (
-	"fmt"
 	"sync"
 	"time"
 	"unsafe"
@@ -27,22 +26,29 @@ func sbytes(data string) []byte {
 	return unsafe.Slice(unsafe.StringData(data), len(data))
 }
 
+type quitSignal struct {
+	code int
+	err  error
+}
+
 // Run starts fzf
-func Run(opts *Options, version string, revision string) {
+func Run(opts *Options) (int, error) {
+	if err := postProcessOptions(opts); err != nil {
+		return ExitError, err
+	}
+
 	defer util.RunAtExitFuncs()
 
+	// Output channel given
+	if opts.Output != nil {
+		opts.Printer = func(str string) {
+			opts.Output <- str
+		}
+	}
+
 	sort := opts.Sort > 0
 	sortCriteria = opts.Criteria
 
-	if opts.Version {
-		if len(revision) > 0 {
-			fmt.Printf("%s (%s)\n", version, revision)
-		} else {
-			fmt.Println(version)
-		}
-		util.Exit(exitOk)
-	}
-
 	// Event channel
 	eventBox := util.NewEventBox()
 
@@ -131,7 +137,7 @@ func Run(opts *Options, version string, revision string) {
 		reader = NewReader(func(data []byte) bool {
 			return chunkList.Push(data)
 		}, eventBox, executor, opts.ReadZero, opts.Filter == nil)
-		go reader.ReadSource(opts.WalkerRoot, opts.WalkerOpts, opts.WalkerSkip)
+		go reader.ReadSource(opts.Input, opts.WalkerRoot, opts.WalkerOpts, opts.WalkerSkip)
 	}
 
 	// Matcher
@@ -147,14 +153,16 @@ func Run(opts *Options, version string, revision string) {
 			forward = true
 		}
 	}
+	cache := NewChunkCache()
+	patternCache := make(map[string]*Pattern)
 	patternBuilder := func(runes []rune) *Pattern {
-		return BuildPattern(
+		return BuildPattern(cache, patternCache,
 			opts.Fuzzy, opts.FuzzyAlgo, opts.Extended, opts.Case, opts.Normalize, forward, withPos,
 			opts.Filter == nil, opts.Nth, opts.Delimiter, runes)
 	}
 	inputRevision := 0
 	snapshotRevision := 0
-	matcher := NewMatcher(patternBuilder, sort, opts.Tac, eventBox, inputRevision)
+	matcher := NewMatcher(cache, patternBuilder, sort, opts.Tac, eventBox, inputRevision)
 
 	// Filtering mode
 	if opts.Filter != nil {
@@ -182,7 +190,7 @@ func Run(opts *Options, version string, revision string) {
 					}
 					return false
 				}, eventBox, executor, opts.ReadZero, false)
-			reader.ReadSource(opts.WalkerRoot, opts.WalkerOpts, opts.WalkerSkip)
+			reader.ReadSource(opts.Input, opts.WalkerRoot, opts.WalkerOpts, opts.WalkerSkip)
 		} else {
 			eventBox.Unwatch(EvtReadNew)
 			eventBox.WaitFor(EvtReadFin)
@@ -197,9 +205,9 @@ func Run(opts *Options, version string, revision string) {
 			}
 		}
 		if found {
-			util.Exit(exitOk)
+			return ExitOk, nil
 		}
-		util.Exit(exitNoMatch)
+		return ExitNoMatch, nil
 	}
 
 	// Synchronous search
@@ -210,9 +218,13 @@ func Run(opts *Options, version string, revision string) {
 
 	// Go interactive
 	go matcher.Loop()
+	defer matcher.Stop()
 
 	// Terminal I/O
-	terminal := NewTerminal(opts, eventBox, executor)
+	terminal, err := NewTerminal(opts, eventBox, executor)
+	if err != nil {
+		return ExitError, err
+	}
 	maxFit := 0 // Maximum number of items that can fit on screen
 	padHeight := 0
 	heightUnknown := opts.Height.auto
@@ -258,6 +270,9 @@ func Run(opts *Options, version string, revision string) {
 		header = make([]string, 0, opts.HeaderLines)
 		go reader.restart(command, environ)
 	}
+
+	exitCode := ExitOk
+	stop := false
 	for {
 		delay := true
 		ticks++
@@ -278,7 +293,11 @@ func Run(opts *Options, version string, revision string) {
 					if reading {
 						reader.terminate()
 					}
-					util.Exit(value.(int))
+					quitSignal := value.(quitSignal)
+					exitCode = quitSignal.code
+					err = quitSignal.err
+					stop = true
+					return
 				case EvtReadNew, EvtReadFin:
 					if evt == EvtReadFin && nextCommand != nil {
 						restart(*nextCommand, nextEnviron)
@@ -378,10 +397,11 @@ func Run(opts *Options, version string, revision string) {
 									for i := 0; i < count; i++ {
 										opts.Printer(val.Get(i).item.AsString(opts.Ansi))
 									}
-									if count > 0 {
-										util.Exit(exitOk)
+									if count == 0 {
+										exitCode = ExitNoMatch
 									}
-									util.Exit(exitNoMatch)
+									stop = true
+									return
 								}
 								determine(val.final)
 							}
@@ -392,6 +412,9 @@ func Run(opts *Options, version string, revision string) {
 			}
 			events.Clear()
 		})
+		if stop {
+			break
+		}
 		if delay && reading {
 			dur := util.DurWithin(
 				time.Duration(ticks)*coordinatorDelayStep,
@@ -399,4 +422,5 @@ func Run(opts *Options, version string, revision string) {
 			time.Sleep(dur)
 		}
 	}
+	return exitCode, err
 }