fzf/src/reader.go
2020-03-14 21:43:35 +09:00

202 lines
4.2 KiB
Go

package fzf
import (
"bufio"
"context"
"io"
"os"
"os/exec"
"path/filepath"
"sync"
"sync/atomic"
"time"
"github.com/junegunn/fzf/src/util"
"github.com/saracen/walker"
)
// Reader reads from command or standard input
type Reader struct {
pusher func([]byte) bool
eventBox *util.EventBox
delimNil bool
event int32
finChan chan bool
mutex sync.Mutex
exec *exec.Cmd
command *string
killed bool
wait bool
}
// NewReader returns new Reader object
func NewReader(pusher func([]byte) bool, eventBox *util.EventBox, delimNil bool, wait bool) *Reader {
return &Reader{pusher, eventBox, delimNil, int32(EvtReady), make(chan bool, 1), sync.Mutex{}, nil, nil, false, wait}
}
func (r *Reader) startEventPoller() {
go func() {
ptr := &r.event
pollInterval := readerPollIntervalMin
for {
if atomic.CompareAndSwapInt32(ptr, int32(EvtReadNew), int32(EvtReady)) {
r.eventBox.Set(EvtReadNew, (*string)(nil))
pollInterval = readerPollIntervalMin
} else if atomic.LoadInt32(ptr) == int32(EvtReadFin) {
if r.wait {
r.finChan <- true
}
return
} else {
pollInterval += readerPollIntervalStep
if pollInterval > readerPollIntervalMax {
pollInterval = readerPollIntervalMax
}
}
time.Sleep(pollInterval)
}
}()
}
func (r *Reader) fin(success bool) {
atomic.StoreInt32(&r.event, int32(EvtReadFin))
if r.wait {
<-r.finChan
}
r.mutex.Lock()
ret := r.command
if success || r.killed {
ret = nil
}
r.mutex.Unlock()
r.eventBox.Set(EvtReadFin, ret)
}
func (r *Reader) terminate() {
r.mutex.Lock()
defer func() { r.mutex.Unlock() }()
r.killed = true
if r.exec != nil && r.exec.Process != nil {
util.KillCommand(r.exec)
} else if defaultCommand != "" {
os.Stdin.Close()
}
}
func (r *Reader) restart(command string) {
r.event = int32(EvtReady)
r.startEventPoller()
success := r.readFromCommand(nil, command)
r.fin(success)
}
// ReadSource reads data from the default command or from standard input
func (r *Reader) ReadSource() {
r.startEventPoller()
var success bool
if util.IsTty() {
// The default command for *nix requires bash
shell := "bash"
cmd := os.Getenv("FZF_DEFAULT_COMMAND")
if len(cmd) == 0 {
if defaultCommand != "" {
success = r.readFromCommand(&shell, defaultCommand)
} else {
success = r.readFiles()
}
} else {
success = r.readFromCommand(nil, cmd)
}
} else {
success = r.readFromStdin()
}
r.fin(success)
}
func (r *Reader) feed(src io.Reader) {
delim := byte('\n')
if r.delimNil {
delim = '\000'
}
reader := bufio.NewReaderSize(src, readerBufferSize)
for {
// ReadBytes returns err != nil if and only if the returned data does not
// end in delim.
bytea, err := reader.ReadBytes(delim)
byteaLen := len(bytea)
if byteaLen > 0 {
if err == nil {
// get rid of carriage return if under Windows:
if util.IsWindows() && byteaLen >= 2 && bytea[byteaLen-2] == byte('\r') {
bytea = bytea[:byteaLen-2]
} else {
bytea = bytea[:byteaLen-1]
}
}
if r.pusher(bytea) {
atomic.StoreInt32(&r.event, int32(EvtReadNew))
}
}
if err != nil {
break
}
}
}
func (r *Reader) readFromStdin() bool {
r.feed(os.Stdin)
return true
}
func (r *Reader) readFiles() bool {
r.killed = false
fn := func(path string, mode os.FileInfo) error {
path = filepath.Clean(path)
if path != "." {
isDir := mode.Mode().IsDir()
if isDir && filepath.Base(path)[0] == '.' {
return filepath.SkipDir
}
if !isDir && r.pusher([]byte(path)) {
atomic.StoreInt32(&r.event, int32(EvtReadNew))
}
}
r.mutex.Lock()
defer r.mutex.Unlock()
if r.killed {
return context.Canceled
}
return nil
}
cb := walker.WithErrorCallback(func(pathname string, err error) error {
return nil
})
return walker.Walk(".", fn, cb) == nil
}
func (r *Reader) readFromCommand(shell *string, command string) bool {
r.mutex.Lock()
r.killed = false
r.command = &command
if shell != nil {
r.exec = util.ExecCommandWith(*shell, command, true)
} else {
r.exec = util.ExecCommand(command, true)
}
out, err := r.exec.StdoutPipe()
if err != nil {
r.mutex.Unlock()
return false
}
err = r.exec.Start()
r.mutex.Unlock()
if err != nil {
return false
}
r.feed(out)
return r.exec.Wait() == nil
}