Implement process memory usage for Linux.

Author: Mysticial

Common/Cpp/MemoryUtilization/MemoryUtilization_Linux.tpp

@@ -19,20 +19,56 @@ namespace PokemonAutomation{
 
 
 
+uint64_t parse_integer(const char*& ptr){
+    uint64_t ret = 0;
+
+    //  Skip the white space.
+    while (true){
+        char ch = *ptr;
+        switch (ch){
+        case '\0':
+            return ret;
+        case ' ':
+        case '\t':
+            ptr++;
+            continue;
+        default:;
+        }
+        break;
+    }
+
+    //  Parse the integer.
+    while (true){
+        char ch = *ptr++;
+        if (ch < '0' || ch > '9'){
+            break;
+        }
+        ret *= 10;
+        ret += ch - '0';
+    }
+
+    return ret;
+}
+
 MemoryUsage process_memory_usage(){
     MemoryUsage usage;
 
+    uint64_t page_size = sysconf(_SC_PAGE_SIZE);
 
-    usage.total_system_memory = (uint64_t)sysconf(_SC_PHYS_PAGES) * sysconf(_SC_PAGE_SIZE);
+    usage.total_system_memory = (uint64_t)sysconf(_SC_PHYS_PAGES) * page_size;
 
     {
         uint64_t bytes = 0;
 
+        //  Running this at our poll rate is a terrible idea.
+#if 1
         const std::string TOKEN = "MemAvailable:";
 
         std::ifstream file("/proc/meminfo");
         std::string line;
         while (std::getline(file, line)){
+//            cout << line << endl;
+
             size_t pos = line.find(TOKEN);
             if (pos == std::string::npos){
                 continue;
@@ -41,33 +77,50 @@ MemoryUsage process_memory_usage(){
             //  Skip the token.
             pos += TOKEN.size();
 
-            //  Skip the white space.
-            while (line[pos] != '\0' && line[pos] == ' '){
-                pos++;
-            }
-
-            //  Parse the integer.
-            while (true){
-                char ch = line[pos++];
-                if (ch < '0' || ch > '9'){
-                    break;
-                }
-                bytes *= 10;
-                bytes += ch - '0';
-            }
-            bytes *= 1024;
+            const char* ptr = &line[pos];
+            bytes = parse_integer(ptr) * 1024;
 
             break;
         }
+#endif
 
         if (bytes == 0){
-            bytes = (uint64_t)sysconf(_SC_AVPHYS_PAGES) * sysconf(_SC_PAGE_SIZE);
+            bytes = (uint64_t)sysconf(_SC_AVPHYS_PAGES) * page_size;
         }
         bytes = std::min(bytes, usage.total_system_memory);
 
         usage.total_used_system_memory = usage.total_system_memory - bytes;
     }
 
+    uint64_t swapped = 0;
+    {
+        const std::string VmRSS = "VmRSS:";
+        const std::string VmSwap = "VmSwap:";
+
+        pid_t current_pid = getpid();
+        std::ifstream file("/proc/" + std::to_string(current_pid) + "/status");
+        std::string line;
+        while (std::getline(file, line)){
+//            cout << line << endl;
+
+            size_t pos = line.find(VmRSS);
+            if (pos != std::string::npos){
+                pos += VmRSS.size();
+                const char* ptr = &line[pos];
+                usage.process_physical_memory = parse_integer(ptr) * 1024;
+                continue;
+            }
+            pos = line.find(VmSwap);
+            if (pos != std::string::npos){
+                pos += VmSwap.size();
+                const char* ptr = &line[pos];
+                swapped = parse_integer(ptr) * 1024;
+                continue;
+            }
+        }
+        usage.process_virtual_memory = usage.process_physical_memory + swapped;
+    }
+
     return usage;
 }