Add option to merge processes of same application

Experimental - Linux only

Closes: htop-dev#301

Author: cgzones

Action.c

@@ -250,6 +250,11 @@ static Htop_Reaction actionExpandOrCollapseAllBranches(State* st) {
    return HTOP_REFRESH | HTOP_SAVE_SETTINGS;
 }
 
+static Htop_Reaction actionToggleMergeApplication(State* st) {
+   st->settings->mergeApplications = !st->settings->mergeApplications;
+   return HTOP_REFRESH | HTOP_SAVE_SETTINGS;
+}
+
 static Htop_Reaction actionIncFilter(State* st) {
    IncSet* inc = (st->mainPanel)->inc;
    IncSet_activate(inc, INC_FILTER, (Panel*)st->mainPanel);
@@ -543,6 +548,7 @@ static const struct {
    { .key = "      x: ", .roInactive = false, .info = "list file locks of process" },
    { .key = "      s: ", .roInactive = true,  .info = "trace syscalls with strace" },
    { .key = "      w: ", .roInactive = false, .info = "wrap process command in multiple lines" },
+   { .key = "      A: ", .roInactive = false, .info = "Merge processes of same application" },
    { .key = " F2 C S: ", .roInactive = false, .info = "setup" },
    { .key = " F1 h ?: ", .roInactive = false, .info = "show this help screen" },
    { .key = "  F10 q: ", .roInactive = false, .info = "quit" },
@@ -713,6 +719,7 @@ void Action_setBindings(Htop_Action* keys) {
    keys['='] = actionExpandOrCollapse;
    keys['>'] = actionSetSortColumn;
    keys['?'] = actionHelp;
+   keys['A'] = actionToggleMergeApplication;
    keys['C'] = actionSetup;
    keys['F'] = Action_follow;
    keys['H'] = actionToggleUserlandThreads;

DisplayOptionsPanel.c

@@ -101,6 +101,7 @@ DisplayOptionsPanel* DisplayOptionsPanel_new(Settings* settings, ScreenManager*
    Panel_add(super, (Object*) CheckItem_newByRef("- Tree view is always sorted by PID (htop 2 behavior)", &(settings->ss->treeViewAlwaysByPID)));
    Panel_add(super, (Object*) CheckItem_newByRef("- Tree view is collapsed by default", &(settings->ss->allBranchesCollapsed)));
    Panel_add(super, (Object*) CheckItem_newByRef("Show tabs for screens", &(settings->screenTabs)));
+   Panel_add(super, (Object*) CheckItem_newByRef("Merge processes of same applications", &(settings->mergeApplications)));
    Panel_add(super, (Object*) CheckItem_newByRef("Shadow other users' processes", &(settings->shadowOtherUsers)));
    Panel_add(super, (Object*) CheckItem_newByRef("Hide kernel threads", &(settings->hideKernelThreads)));
    Panel_add(super, (Object*) CheckItem_newByRef("Hide userland process threads", &(settings->hideUserlandThreads)));

Process.c

@@ -786,6 +786,11 @@ void Process_writeField(const Process* this, RichString* str, ProcessField field
       }
       const ScreenSettings* ss = this->settings->ss;
       if (!ss->treeView || this->indent == 0) {
+         if (this->merged > 1) {
+            char merged[16];
+            xSnprintf(merged, sizeof(merged), "[%u] ", this->merged);
+            RichString_appendAscii(str, CRT_colors[PROCESS_SHADOW], merged);
+         }
          Process_writeCommand(this, attr, baseattr, str);
          return;
       }
@@ -820,6 +825,11 @@ void Process_writeField(const Process* this, RichString* str, ProcessField field
       const char* draw = CRT_treeStr[lastItem ? TREE_STR_BEND : TREE_STR_RTEE];
       xSnprintf(buf, n, "%s%s ", draw, this->showChildren ? CRT_treeStr[TREE_STR_SHUT] : CRT_treeStr[TREE_STR_OPEN] );
       RichString_appendWide(str, CRT_colors[PROCESS_TREE], buffer);
+      if (this->merged > 1) {
+         char merged[16];
+         xSnprintf(merged, sizeof(merged), "[%u] ", this->merged);
+         RichString_appendAscii(str, CRT_colors[PROCESS_SHADOW], merged);
+      }
       Process_writeCommand(this, attr, baseattr, str);
       return;
    }
@@ -1088,6 +1098,40 @@ int Process_pidCompare(const void* v1, const void* v2) {
    return SPACESHIP_NUMBER(p1->pid, p2->pid);
 }
 
+static bool isTransitiveChildOf(const Process* child, const Process* parent) {
+   assert(child->processList == parent->processList);
+
+   for (const Process* tChild = child; tChild; tChild = ProcessList_findProcess(parent->processList, Process_getParentPid(tChild)))
+      if (Process_isChildOf(tChild, parent->pid))
+         return true;
+
+   return false;
+}
+
+int Process_sameApplication(const Process* v1, const Process* v2) {
+   const char* exe1 = v1->procExe;
+   const char* exe2 = v2->procExe;
+
+   if (!exe1 || !exe2 || !String_eq(exe1, exe2))
+      return 0;
+
+
+   if (v1->session != v2->session)
+      return 0;
+
+   // we can compare pointers since the field user points to a hashtable entry
+   if (v1->user != v2->user)
+      return 0;
+
+   if (isTransitiveChildOf(v1, v2))
+      return 2;
+
+   if (isTransitiveChildOf(v2, v1))
+      return 1;
+
+   return 0;
+}
+
 int Process_compare(const void* v1, const void* v2) {
    const Process* p1 = (const Process*)v1;
    const Process* p2 = (const Process*)v2;
@@ -1251,3 +1295,33 @@ void Process_updateExe(Process* this, const char* exe) {
    }
    this->mergedCommand.exeChanged = true;
 }
+
+void Process_mergeData(Process* p1, const Process* p2) {
+
+   p1->percent_cpu += p2->percent_cpu;
+   p1->percent_mem += p2->percent_mem;
+   // keep COMM
+   p1->majflt += p2->majflt;
+   p1->minflt += p2->minflt;
+   p1->m_resident += p2->m_resident;
+   p1->m_virt += p2->m_virt;
+   // store min NICE
+   p1->nice = MINIMUM(p1->nice, p2->nice);
+   p1->nlwp += p2->nlwp;
+   // keep PGRP
+   // keep PID
+   // keep PPID
+   p1->priority = MAXIMUM(p1->priority, p2->priority);
+   // keep PROCESSOR
+   // keep SESSION
+   p1->starttime_ctime = MINIMUM(p1->starttime_ctime, p2->starttime_ctime);
+   // keep STATE
+   // keep ST_UID
+   p1->time += p2->time;
+   // keep TGID
+   // keep TPGID
+   // keep TTY_NR
+   // keep USER
+
+   p1->merged += p2->merged;
+}

Process.h

@@ -240,6 +240,9 @@ typedef struct Process_ {
    /* Whether to show children of this process in tree-mode */
    bool showChildren;
 
+   /* The number of processes merged into this one. */
+   unsigned int merged;
+
    /*
     * Internal time counts for showing new and exited processes.
     */
@@ -284,6 +287,11 @@ typedef struct ProcessFieldData_ {
 // Implemented in platform-specific code:
 void Process_writeField(const Process* this, RichString* str, ProcessField field);
 int Process_compare(const void* v1, const void* v2);
+/* returns 1 on match and if v1 is the master process,
+ *         2 on match and if v2 is the master process,
+ *         0 else */
+int Process_sameApplication(const Process* p1, const Process* p2);
+void Process_mergeData(Process* p1, const Process* p2);
 void Process_delete(Object* cast);
 extern const ProcessFieldData Process_fields[LAST_PROCESSFIELD];
 #define PROCESS_MIN_PID_DIGITS 5
@@ -297,12 +305,16 @@ typedef Process* (*Process_New)(const struct Settings_*);
 typedef void (*Process_WriteField)(const Process*, RichString*, ProcessField);
 typedef int (*Process_CompareByKey)(const Process*, const Process*, ProcessField);
 typedef const char* (*Process_GetCommandStr)(const Process*);
+typedef int (*Process_SameApplication)(const Process*, const Process*);
+typedef void (*Process_MergeData)(Process*, const Process*);
 
 typedef struct ProcessClass_ {
    const ObjectClass super;
    const Process_WriteField writeField;
    const Process_CompareByKey compareByKey;
    const Process_GetCommandStr getCommandStr;
+   const Process_SameApplication sameApplication;
+   const Process_MergeData mergeData;
 } ProcessClass;
 
 #define As_Process(this_)                              ((const ProcessClass*)((this_)->super.klass))