From 60a59bcfdb3c2404a468cc314b7afde85ee35e1b Mon Sep 17 00:00:00 2001
From: Sebastien Douheret <sebastien.douheret@iot.bzh>
Date: Fri, 26 Jan 2018 17:19:13 +0100
Subject: [PATCH] Don't send command output too fast.

Changes done in eows package of xds-common now allow to accumulate command output during a period
of time (eg. 500ms) or up to the end of a line.
Usage of this feature is mandatory to avoid to post to
much buffers in websocket and consequently flood client (eg. web-browser)

Signed-off-by: Sebastien Douheret <sebastien.douheret@iot.bzh>
---
 lib/xdsserver/sdk.go | 73 ++++++++++------------------------------------------
 1 file changed, 13 insertions(+), 60 deletions(-)

diff --git a/lib/xdsserver/sdk.go b/lib/xdsserver/sdk.go
index 633fbee..2736246 100644
--- a/lib/xdsserver/sdk.go
+++ b/lib/xdsserver/sdk.go
@@ -20,7 +20,6 @@ package xdsserver
 import (
 	"encoding/json"
 	"fmt"
-	"os"
 	"os/exec"
 	"path"
 	"strconv"
@@ -62,9 +61,6 @@ type CrossSDK struct {
 	scripts    map[string]string
 	installCmd *eows.ExecOverWS
 	removeCmd  *eows.ExecOverWS
-
-	bufStdout string
-	bufStderr string
 }
 
 // ListCrossSDK List all available and installed SDK  (call "db-dump" script)
@@ -233,28 +229,13 @@ func (s *CrossSDK) Install(file string, force bool, timeout int, args []string,
 	// Create new instance to execute command and sent output over WS
 	s.installCmd = eows.New(s.scripts[scriptAdd], cmdArgs, sess.IOSocket, sess.ID, cmdID)
 	s.installCmd.Log = s.Log
+	s.installCmd.LineTimeSpan = 500 * time.Millisecond.Nanoseconds()
 	if timeout > 0 {
 		s.installCmd.CmdExecTimeout = timeout
 	} else {
 		s.installCmd.CmdExecTimeout = 30 * 60 // default 30min
 	}
 
-	// FIXME: temporary hack
-	s.bufStdout = ""
-	s.bufStderr = ""
-	SizeBufStdout := 10
-	SizeBufStderr := 2000
-	if valS, ok := os.LookupEnv("XDS_SDK_BUF_STDOUT"); ok {
-		if valI, err := strconv.Atoi(valS); err == nil {
-			SizeBufStdout = valI
-		}
-	}
-	if valS, ok := os.LookupEnv("XDS_SDK_BUF_STDERR"); ok {
-		if valI, err := strconv.Atoi(valS); err == nil {
-			SizeBufStderr = valI
-		}
-	}
-
 	// Define callback for output (stdout+stderr)
 	s.installCmd.OutputCB = func(e *eows.ExecOverWS, stdout, stderr string) {
 		// paranoia
@@ -281,27 +262,18 @@ func (s *CrossSDK) Install(file string, force bool, timeout int, args []string,
 			}
 		}
 
-		// Temporary "Hack": Buffered sent data to avoid freeze in web Browser
-		// FIXME: remove bufStdout & bufStderr and implement better algorithm
-		s.bufStdout += stdout
-		s.bufStderr += stderr
-		if len(s.bufStdout) > SizeBufStdout || len(s.bufStderr) > SizeBufStderr {
-			// Emit event
-			err := (*so).Emit(xsapiv1.EVTSDKManagement, xsapiv1.SDKManagementMsg{
-				CmdID:     e.CmdID,
-				Timestamp: time.Now().String(),
-				Action:    xsapiv1.SdkMgtActionInstall,
-				Sdk:       s.sdk,
-				Progress:  0, // TODO add progress
-				Exited:    false,
-				Stdout:    s.bufStdout,
-				Stderr:    s.bufStderr,
-			})
-			if err != nil {
-				s.Log.Errorf("WS Emit : %v", err)
-			}
-			s.bufStdout = ""
-			s.bufStderr = ""
+		err := (*so).Emit(xsapiv1.EVTSDKManagement, xsapiv1.SDKManagementMsg{
+			CmdID:     e.CmdID,
+			Timestamp: time.Now().String(),
+			Action:    xsapiv1.SdkMgtActionInstall,
+			Sdk:       s.sdk,
+			Progress:  0, // TODO add progress
+			Exited:    false,
+			Stdout:    stdout,
+			Stderr:    stderr,
+		})
+		if err != nil {
+			s.Log.Errorf("WS Emit : %v", err)
 		}
 	}
 
@@ -323,25 +295,6 @@ func (s *CrossSDK) Install(file string, force bool, timeout int, args []string,
 			return
 		}
 
-		// Emit event remaining data in bufStdout/err
-		if len(s.bufStderr) > 0 || len(s.bufStdout) > 0 {
-			err := (*so).Emit(xsapiv1.EVTSDKManagement, xsapiv1.SDKManagementMsg{
-				CmdID:     e.CmdID,
-				Timestamp: time.Now().String(),
-				Action:    xsapiv1.SdkMgtActionInstall,
-				Sdk:       s.sdk,
-				Progress:  50, // TODO add progress
-				Exited:    false,
-				Stdout:    s.bufStdout,
-				Stderr:    s.bufStderr,
-			})
-			if err != nil {
-				s.Log.Errorf("WS Emit : %v", err)
-			}
-			s.bufStdout = ""
-			s.bufStderr = ""
-		}
-
 		// Update SDK status
 		if code == 0 && exitError == nil {
 			s.sdk.LastError = ""
-- 
2.16.6