fix #4318: ui: qemu/Monitor: rework output retention mechanism

instead of saving maximum 500 lines, count commands + lines, and only
if both are over the limit, truncate the command list

this way, at least the last 10 commands + output are always visible, and
no visible output is truncated, while still not letting the log
grow infinitely

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>

diff --git a/www/manager6/qemu/Monitor.js b/www/manager6/qemu/Monitor.js
index d85018e6b4f279563ad798bd2029b2f263e15261..7f1626e3c4c89324beac8e2d7e42b111e393c8ed 100644 (file)
--- a/www/manager6/qemu/Monitor.js
+++ b/www/manager6/qemu/Monitor.js
@@ -3,7 +3,10 @@ Ext.define('PVE.qemu.Monitor', {
 
     alias: 'widget.pveQemuMonitor',
 
-    maxLines: 500,
+    // ouput is trimmed when it's over both commandLimit and lineLimit
+    // by removing the first commands and their output
+    commandLimit: 10,
+    lineLimit: 5000,
 
     initComponent: function() {
        var me = this;
@@ -20,7 +23,7 @@ Ext.define('PVE.qemu.Monitor', {
 
        var history = [];
        var histNum = -1;
-       var lines = [];
+       let commands = [];
 
        var textbox = Ext.createWidget('panel', {
            region: 'center',
@@ -45,19 +48,23 @@ Ext.define('PVE.qemu.Monitor', {
        };
 
        var refresh = function() {
-           textbox.update('<pre>' + lines.join('\n') + '</pre>');
+           textbox.update(`<pre>${commands.flat(2).join('\n')}</pre>`);
            scrollToEnd();
        };
 
-       var addLine = function(line) {
-           lines.push(line);
-           if (lines.length > me.maxLines) {
-               lines.shift();
+       let recordInput = line => {
+           commands.push([line]);
+
+           // drop oldest commands and their output until we're not over both limits anymore
+           while (commands.length > me.commandLimit && commands.flat(2).length > me.lineLimit) {
+               commands.shift();
            }
        };
 
+       let addResponse = lines => commands[commands.length - 1].push(lines);
+
        var executeCmd = function(cmd) {
-           addLine("# " + Ext.htmlEncode(cmd));
+           recordInput("# " + Ext.htmlEncode(cmd), true);
            if (cmd) {
                history.unshift(cmd);
                if (history.length > 20) {
@@ -74,9 +81,7 @@ Ext.define('PVE.qemu.Monitor', {
                waitMsgTarget: me,
                success: function(response, opts) {
                    var res = response.result.data;
-                   Ext.Array.each(res.split('\n'), function(line) {
-                       addLine(Ext.htmlEncode(line));
-                   });
+                   addResponse(res.split('\n').map(line => Ext.htmlEncode(line)));
                    refresh();
                },
                failure: function(response, opts) {
@@ -102,7 +107,7 @@ Ext.define('PVE.qemu.Monitor', {
                    listeners: {
                        afterrender: function(f) {
                            f.focus(false);
-                           addLine("Type 'help' for help.");
+                           recordInput("Type 'help' for help.");
                            refresh();
                        },
                        specialkey: function(f, e) {