Use sysinfo in backend.

gpt4all-backend/sysinfo.h

@@ -0,0 +1,61 @@
+#ifndef SYSINFO_H
+#define SYSINFO_H
+
+#include <fstream>
+#include <string>
+#include <sstream>
+#include <iomanip>
+
+#if defined(__linux__)
+#include <unistd.h>
+#elif defined(__APPLE__)
+#include <sys/types.h>
+#include <sys/sysctl.h>
+#elif defined(_WIN32)
+#include <windows.h>
+#endif
+
+static long long getSystemTotalRAMInBytes()
+{
+    long long totalRAM = 0;
+
+#if defined(__linux__)
+    std::ifstream file("/proc/meminfo");
+    std::string line;
+    while (std::getline(file, line)) {
+        if (line.find("MemTotal") != std::string::npos) {
+            std::string memTotalStr = line.substr(line.find(":") + 1);
+            memTotalStr.erase(0, memTotalStr.find_first_not_of(" "));
+            memTotalStr = memTotalStr.substr(0, memTotalStr.find(" "));
+            totalRAM = std::stoll(memTotalStr) * 1024;  // Convert from KB to bytes
+            break;
+        }
+    }
+    file.close();
+#elif defined(__APPLE__)
+    int mib[2] = {CTL_HW, HW_MEMSIZE};
+    size_t length = sizeof(totalRAM);
+    sysctl(mib, 2, &totalRAM, &length, NULL, 0);
+#elif defined(_WIN32)
+    MEMORYSTATUSEX memoryStatus;
+    memoryStatus.dwLength = sizeof(memoryStatus);
+    GlobalMemoryStatusEx(&memoryStatus);
+    totalRAM = memoryStatus.ullTotalPhys;
+#endif
+
+    return totalRAM;
+}
+
+static double getSystemTotalRAMInGB()
+{
+    return static_cast<double>(getSystemTotalRAMInBytes()) / (1024 * 1024 * 1024);
+}
+
+static std::string getSystemTotalRAMInGBString()
+{
+    std::stringstream ss;
+    ss << std::fixed << std::setprecision(2) << getSystemTotalRAMInGB() << " GB";
+    return ss.str();
+}
+
+#endif // SYSINFO_H