v0.2.54..v0.2.55 changeset SystemInfo.h

diff --git a/tgs/src/main/cpp/tgs/System/SystemInfo.h b/tgs/src/main/cpp/tgs/System/SystemInfo.h
index c908184..2426692 100644
--- a/tgs/src/main/cpp/tgs/System/SystemInfo.h
+++ b/tgs/src/main/cpp/tgs/System/SystemInfo.h
@@ -22,7 +22,7 @@
  * This will properly maintain the copyright information. DigitalGlobe
  * copyrights will be updated automatically.
  *
- * @copyright Copyright (C) 2015, 2017, 2018 DigitalGlobe (http://www.digitalglobe.com/)
+ * @copyright Copyright (C) 2015, 2017, 2018, 2020 DigitalGlobe (http://www.digitalglobe.com/)
  */
 #ifndef __SYSTEM_INFO_H__
 #define __SYSTEM_INFO_H__
@@ -34,18 +34,150 @@
 
 namespace Tgs
 {
+  /**
+   * Utilities for obtaining operating system info
+   *
+   * Portions of this source code are derived from the following:
+   *
+   * http://stackoverflow.com/questions/669438/how-to-get-memory-usage-at-run-time-in-c
+   * https://stackoverflow.com/questions/63166/how-to-determine-cpu-and-memory-consumption-from-inside-a-process
+   */
   class TGS_EXPORT SystemInfo
   {
   public:
+
+    /**
+     * Determines the number of processors available in the system
+     *
+     * @return the number of processors
+     */
     static int getNumberOfProcessors();
 
-    static void getMemoryUsage(long& vmUsage, long &residentSet);
+    /**
+     * Returns the amount of total configured system virtual memory
+     *
+     * @return memory size in bytes
+     */
+    static long getTotalSystemVirtualMemory();
+
+    /**
+     * Determines the amount of total system virtual memory in use
+     *
+     * @return memory size in bytes
+     */
+    static long getSystemVirtualMemoryUsed();
+
+    /**
+     * Determines the amount of virtual memory used by the calling process
+     *
+     * @return memory size in bytes
+     */
+    static long getCurrentProcessVirtualMemoryUsage();
+
+    /**
+     * Determines the amount of virtual memory available
+     *
+     * @return memory size in bytes
+     */
+    static long getVirtualMemoryAvailable();
+
+    /**
+     * Determines the percentage of total virtual memory in use out of the total configured system
+     * virtual memory
+     *
+     * @return memory size in bytes
+     */
+    static double getPercentageOfVirtualMemoryUsed();
+
+    /**
+     * Determines the percentage of virtual memory in use by the calling process out of the total
+     * configured system virtual memory
+     *
+     * @return memory size in bytes
+     */
+    static double getPercentageOfVirtualMemoryUsedByCurrentProcess();
+
+    /**
+     * Returns the amount of total configured system physical memory
+     *
+     * @return memory size in bytes
+     */
+    static long getTotalSystemPhysicalMemory();
+
+    /**
+     * Determines the amount of total system physical memory in use
+     *
+     * @return memory size in bytes
+     */
+    static long getSystemPhysicalMemoryUsed();
+
+    /**
+     * Determines the amount of physical memory used by the calling process
+     *
+     * @return memory size in bytes
+     */
+    static long getCurrentProcessPhysicalMemoryUsage();
+
+    /**
+     * Determines the amount of physicalv memory available
+     *
+     * @return memory size in bytes
+     */
+    static long getPhysicalMemoryAvailable();
+
+    /**
+     * Determines the percentage of total physical memory in use out of the total configured system
+     * physical memory
+     *
+     * @return memory size in bytes
+     */
+    static double getPercentageOfPhysicalMemoryUsed();
+
+    /**
+     *
+     * Determines the percentage of physical memory in use by the calling process out of the total
+     * configured system physicalv memory
+     *
+     * @return memory size in bytes
+     */
+    static double getPercentageOfPhysicalMemoryUsedByCurrentProcess();
+
+    /**
+     * A human readable brief summary of the memory used by the calling process
+     *
+     * @return a string
+     */
+    static std::string getCurrentProcessMemoryUsageString();
+
+    /**
+     * A human readable detailed summary of the memory used by the calling process
+     *
+     * @return a string
+     */
+    static std::string getMemoryDetailString();
+
+    /**
+     * Converts bytes to human readable string
+     *
+     * @param bytes the number of bytes to convert
+     * @return a string
+     */
+    static std::string humanReadableStorageSize(long bytes);
+
+  private:
 
-    static long getPhysicalMemoryUsage() { long v; long rss; getMemoryUsage(v, rss); return rss; }
-    static long getVirtualMemoryUsage() { long v; long rss; getMemoryUsage(v, rss); return v; }
+    friend class SystemInfoTest;
 
-    static std::string getMemoryUsageString();
-    static std::string humanReadable(long bytes);
+    /*
+     * Attempts to read the system-dependent data for a process's virtual memory
+     * size and resident set size, and return the results in bytes.
+     *
+     * @param vmUsage populates the current process's virtual memory size in bytes; on failure,
+     * returns 0
+     * @param residentSet populates the current process's resident set size in bytes; on failure,
+     * returns 0
+     */
+    static void _getCurrentProcessMemoryUsage(long& vmUsage, long& residentSet);
   };
 }