v0.0.75

cmdext/pipereader.go

@@ -0,0 +1,146 @@
+package cmdext
+
+import (
+	"bufio"
+	"gogs.mikescher.com/BlackForestBytes/goext/syncext"
+	"io"
+	"sync"
+)
+
+type pipeReader struct {
+	stdout io.ReadCloser
+	stderr io.ReadCloser
+}
+
+// Read ready stdout and stdin until finished
+// also splits both pipes into lines and calld the listener
+func (pr *pipeReader) Read(listener []CommandListener) (string, string, string, error) {
+	type combevt struct {
+		line string
+		stop bool
+	}
+
+	errch := make(chan error, 8)
+
+	wg := sync.WaitGroup{}
+
+	// [1] read raw stdout
+
+	wg.Add(1)
+	stdoutBufferReader, stdoutBufferWriter := io.Pipe()
+	stdout := ""
+	go func() {
+		buf := make([]byte, 128)
+		for true {
+			n, out := pr.stdout.Read(buf)
+
+			if n > 0 {
+				txt := string(buf[:n])
+				stdout += txt
+				_, _ = stdoutBufferWriter.Write(buf[:n])
+				for _, lstr := range listener {
+					lstr.ReadRawStdout(buf[:n])
+				}
+			}
+			if out == io.EOF {
+				break
+			}
+			if out != nil {
+				errch <- out
+				break
+			}
+		}
+		_ = stdoutBufferWriter.Close()
+		wg.Done()
+	}()
+
+	// [2] read raw stderr
+
+	wg.Add(1)
+	stderrBufferReader, stderrBufferWriter := io.Pipe()
+	stderr := ""
+	go func() {
+		buf := make([]byte, 128)
+		for true {
+			n, err := pr.stderr.Read(buf)
+
+			if n > 0 {
+				txt := string(buf[:n])
+				stderr += txt
+				_, _ = stderrBufferWriter.Write(buf[:n])
+				for _, lstr := range listener {
+					lstr.ReadRawStderr(buf[:n])
+				}
+			}
+			if err == io.EOF {
+				break
+			}
+			if err != nil {
+				errch <- err
+				break
+			}
+		}
+		_ = stderrBufferWriter.Close()
+		wg.Done()
+	}()
+
+	combch := make(chan combevt, 32)
+
+	// [3] collect stdout line-by-line
+
+	wg.Add(1)
+	go func() {
+		scanner := bufio.NewScanner(stdoutBufferReader)
+		for scanner.Scan() {
+			txt := scanner.Text()
+			for _, lstr := range listener {
+				lstr.ReadStdoutLine(txt)
+			}
+			combch <- combevt{txt, false}
+		}
+		combch <- combevt{"", true}
+		wg.Done()
+	}()
+
+	// [4] collect stderr line-by-line
+
+	wg.Add(1)
+	go func() {
+		scanner := bufio.NewScanner(stderrBufferReader)
+		for scanner.Scan() {
+			txt := scanner.Text()
+			for _, lstr := range listener {
+				lstr.ReadStderrLine(txt)
+			}
+			combch <- combevt{txt, false}
+		}
+		combch <- combevt{"", true}
+		wg.Done()
+	}()
+
+	// [5] combine stdcombined
+
+	wg.Add(1)
+	stdcombined := ""
+	go func() {
+		stopctr := 0
+		for stopctr < 2 {
+			vvv := <-combch
+			if vvv.stop {
+				stopctr++
+			} else {
+				stdcombined += vvv.line + "\n" // this comes from bufio.Scanner and has no newlines...
+			}
+		}
+		wg.Done()
+	}()
+
+	// wait for all (5) goroutines to finish
+	wg.Wait()
+
+	if err, ok := syncext.ReadNonBlocking(errch); ok {
+		return "", "", "", err
+	}
+
+	return stdout, stderr, stdcombined, nil
+}