Refactor code for rendering command line cache

Fixes #1008

AvailableMetersPanel.c

@@ -79,6 +79,7 @@ static HandlerResult AvailableMetersPanel_eventHandler(Panel* super, int ch) {
    }
    if (update) {
       this->settings->changed = true;
+      this->settings->lastUpdate++;
       Header_calculateHeight(header);
       Header_updateData(header);
       Header_draw(header);

ColorsPanel.c

@@ -68,6 +68,7 @@ static HandlerResult ColorsPanel_eventHandler(Panel* super, int ch) {
 
       this->settings->colorScheme = mark;
       this->settings->changed = true;
+      this->settings->lastUpdate++;
 
       CRT_setColors(mark);
       clear();

DisplayOptionsPanel.c

@@ -72,6 +72,7 @@ static HandlerResult DisplayOptionsPanel_eventHandler(Panel* super, int ch) {
 
    if (result == HANDLED) {
       this->settings->changed = true;
+      this->settings->lastUpdate++;
       Header* header = this->scr->header;
       Header_calculateHeight(header);
       Header_reinit(header);

HeaderOptionsPanel.c

@@ -52,6 +52,7 @@ static HandlerResult HeaderOptionsPanel_eventHandler(Panel* super, int ch) {
 
       Header_setLayout(this->scr->header, mark);
       this->settings->changed = true;
+      this->settings->lastUpdate++;
 
       ScreenManager_resize(this->scr);
 

MetersPanel.c

@@ -184,6 +184,7 @@ static HandlerResult MetersPanel_eventHandler(Panel* super, int ch) {
    if (result == HANDLED || sideMove) {
       Header* header = this->scr->header;
       this->settings->changed = true;
+      this->settings->lastUpdate++;
       Header_calculateHeight(header);
       ScreenManager_resize(this->scr);
    }

Process.c

@@ -414,6 +414,8 @@ void Process_makeCommandStr(Process* this) {
    bool stripExeFromCmdline = settings->stripExeFromCmdline;
    bool showThreadNames = settings->showThreadNames;
 
+   uint64_t settingsStamp = settings->lastUpdate;
+
    /* Nothing to do to (Re)Generate the Command string, if the process is:
     * - a kernel thread, or
     * - a zombie from before being under htop's watch, or
@@ -422,52 +424,27 @@ void Process_makeCommandStr(Process* this) {
       return;
    if (this->state == ZOMBIE && !this->mergedCommand.str)
       return;
-   if (Process_isUserlandThread(this) && settings->showThreadNames && (showThreadNames == mc->prevShowThreadNames) && (mc->prevMergeSet == showMergedCommand))
-      return;
 
    /* this->mergedCommand.str needs updating only if its state or contents changed.
     * Its content is based on the fields cmdline, comm, and exe. */
-   if (
+   if (mc->lastUpdate >= settingsStamp)
-      mc->prevMergeSet == showMergedCommand &&
-      mc->prevPathSet == showProgramPath &&
-      mc->prevCommSet == searchCommInCmdline &&
-      mc->prevCmdlineSet == stripExeFromCmdline &&
-      mc->prevShowThreadNames == showThreadNames &&
-      !mc->cmdlineChanged &&
-      !mc->commChanged &&
-      !mc->exeChanged
-   ) {
       return;
-   }
+
+   mc->lastUpdate = settingsStamp;
 
    /* The field separtor "│" has been chosen such that it will not match any
     * valid string used for searching or filtering */
    const char* SEPARATOR = CRT_treeStr[TREE_STR_VERT];
    const int SEPARATOR_LEN = strlen(SEPARATOR);
 
-   /* Check for any changed fields since we last built this string */
-   if (mc->cmdlineChanged || mc->commChanged || mc->exeChanged) {
-      free(mc->str);
    /* Accommodate the column text, two field separators and terminating NUL */
    size_t maxLen = 2 * SEPARATOR_LEN + 1;
    maxLen += this->cmdline ? strlen(this->cmdline) : strlen("(zombie)");
    maxLen += this->procComm ? strlen(this->procComm) : 0;
    maxLen += this->procExe ? strlen(this->procExe) : 0;
 
+   free(mc->str);
    mc->str = xCalloc(1, maxLen);
-   }
-
-   /* Preserve the settings used in this run */
-   mc->prevMergeSet = showMergedCommand;
-   mc->prevPathSet = showProgramPath;
-   mc->prevCommSet = searchCommInCmdline;
-   mc->prevCmdlineSet = stripExeFromCmdline;
-   mc->prevShowThreadNames = showThreadNames;
-
-   /* Mark everything as unchanged */
-   mc->cmdlineChanged = false;
-   mc->commChanged = false;
-   mc->exeChanged = false;
 
    /* Reset all locations that need extra handling when actually displaying */
    mc->highlightCount = 0;
@@ -1204,7 +1181,8 @@ void Process_updateComm(Process* this, const char* comm) {
 
    free(this->procComm);
    this->procComm = comm ? xStrdup(comm) : NULL;
-   this->mergedCommand.commChanged = true;
+
+   this->mergedCommand.lastUpdate = 0;
 }
 
 static int skipPotentialPath(const char* cmdline, int end) {
@@ -1244,7 +1222,8 @@ void Process_updateCmdline(Process* this, const char* cmdline, int basenameStart
    this->cmdline = cmdline ? xStrdup(cmdline) : NULL;
    this->cmdlineBasenameStart = (basenameStart || !cmdline) ? basenameStart : skipPotentialPath(cmdline, basenameEnd);
    this->cmdlineBasenameEnd = basenameEnd;
-   this->mergedCommand.cmdlineChanged = true;
+
+   this->mergedCommand.lastUpdate = 0;
 }
 
 void Process_updateExe(Process* this, const char* exe) {
@@ -1263,7 +1242,8 @@ void Process_updateExe(Process* this, const char* exe) {
       this->procExe = NULL;
       this->procExeBasenameOffset = 0;
    }
-   this->mergedCommand.exeChanged = true;
+
+   this->mergedCommand.lastUpdate = 0;
 }
 
 uint8_t Process_fieldWidths[LAST_PROCESSFIELD] = { 0 };

Process.h

@@ -96,17 +96,10 @@ typedef struct ProcessCmdlineHighlight_ {
  * Process_writeCommand to color the string. str will be NULL for kernel
  * threads and zombies */
 typedef struct ProcessMergedCommand_ {
+   uint64_t lastUpdate;                        /* Marker based on settings->lastUpdate to track when the rendering needs refreshing */
    char* str;                                  /* merged Command string */
    size_t highlightCount;                      /* how many portions of cmdline to highlight */
    ProcessCmdlineHighlight highlights[8];      /* which portions of cmdline to highlight */
-   bool cmdlineChanged : 1;                    /* whether cmdline changed */
-   bool exeChanged : 1;                        /* whether exe changed */
-   bool commChanged : 1;                       /* whether comm changed */
-   bool prevMergeSet : 1;                      /* whether showMergedCommand was set */
-   bool prevPathSet : 1;                       /* whether showProgramPath was set */
-   bool prevCommSet : 1;                       /* whether findCommInCmdline was set */
-   bool prevCmdlineSet : 1;                    /* whether stripExeFromCmdline was set */
-   bool prevShowThreadNames : 1;               /* whether showThreadNames was set */
 } ProcessMergedCommand;
 
 typedef struct Process_ {

ScreensPanel.c

@@ -315,6 +315,7 @@ void ScreensPanel_update(Panel* super) {
    ScreensPanel* this = (ScreensPanel*) super;
    int size = Panel_size(super);
    this->settings->changed = true;
+   this->settings->lastUpdate++;
    this->settings->screens = xReallocArray(this->settings->screens, size + 1, sizeof(ScreenSettings*));
    for (int i = 0; i < size; i++) {
       ScreenListItem* item = (ScreenListItem*) Panel_get(super, i);

Settings.c

@@ -762,6 +762,8 @@ Settings* Settings_new(unsigned int initialCpuCount, Hashtable* dynamicColumns)
    this->ssIndex = 0;
    this->ss = this->screens[this->ssIndex];
 
+   this->lastUpdate = 1;
+
    return this;
 }
 

Settings.h

@@ -96,6 +96,7 @@ typedef struct Settings_ {
    #endif
 
    bool changed;
+   uint64_t lastUpdate;
 } Settings;
 
 #define Settings_cpuId(settings, cpu) ((settings)->countCPUsFromOne ? (cpu)+1 : (cpu))

linux/LinuxProcessList.c

@@ -1351,7 +1351,8 @@ static bool LinuxProcessList_readCmdlineFile(Process* process, openat_arg_t proc
             if (process->procExeDeleted)
                filename[filenameLen - markerLen] = '\0';
 
-            process->mergedCommand.exeChanged |= oldExeDeleted ^ process->procExeDeleted;
+            if (oldExeDeleted != process->procExeDeleted)
+               process->mergedCommand.lastUpdate = 0;
          }
 
          Process_updateExe(process, filename);
@@ -1557,7 +1558,8 @@ static bool LinuxProcessList_recurseProcTree(LinuxProcessList* this, openat_arg_
             lp->m_lrs = (proc->isUserlandThread && parent) ? ((const LinuxProcess*)parent)->m_lrs : 0;
          }
 
-         proc->mergedCommand.exeChanged |= prev ^ proc->usesDeletedLib;
+         if (prev != proc->usesDeletedLib)
+            proc->mergedCommand.lastUpdate = 0;
       }
 
       if ((ss->flags & PROCESS_FLAG_LINUX_SMAPS) && !Process_isKernelThread(proc)) {