Added Linux implementation of method returning free memory even with …

…cached and buffer values.
danielflower · May 22, 2017 · 869bad1 · 869bad1
1 parent 64cb8e6
commit 869bad1
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Showing 9 changed files with 57 additions and 10 deletions.
diff --git a/src/main/java/com/jezhumble/javasysmon/JavaSysMon.java b/src/main/java/com/jezhumble/javasysmon/JavaSysMon.java
@@ -192,6 +192,16 @@ public MemoryStats physical() {
         return monitor.physical();
     }
 
+    /**
+     * Gets the physical memory installed, and the amount free + buffers/cache.
+     *
+     * @return An object containing the amount of physical
+     * memory installed, and the amount free + buffers/cache.
+     */
+    public MemoryStats physicalWithBuffersAndCached() {
+        return monitor.physicalWithBuffersAndCached();
+    }
+
     /**
      * Gets the amount of swap available to the operating system,
      * and the amount that is free.

diff --git a/src/main/java/com/jezhumble/javasysmon/LinuxMonitor.java b/src/main/java/com/jezhumble/javasysmon/LinuxMonitor.java
@@ -19,6 +19,10 @@ class LinuxMonitor implements Monitor {
             Pattern.compile("MemTotal:\\s+(\\d+) kB", Pattern.MULTILINE);
     private static final Pattern FREE_MEMORY_PATTERN =
             Pattern.compile("MemFree:\\s+(\\d+) kB", Pattern.MULTILINE);
+    private static final Pattern BUFFERS_PATTERN =
+            Pattern.compile("Buffers:\\s+(\\d+) kB", Pattern.MULTILINE);
+    private static final Pattern CACHED_PATTERN =
+            Pattern.compile("Cached:\\s+(\\d+) kB", Pattern.MULTILINE);
     private static final Pattern TOTAL_SWAP_PATTERN =
             Pattern.compile("SwapTotal:\\s+(\\d+) kB", Pattern.MULTILINE);
     private static final Pattern FREE_SWAP_PATTERN =
@@ -35,6 +39,8 @@ class LinuxMonitor implements Monitor {
             Pattern.compile("([\\d]*).*");
     private static final Pattern DISTRIBUTION =
             Pattern.compile("DISTRIB_DESCRIPTION=\"(.*)\"", Pattern.MULTILINE);
+    public static final String PROC_MEMINFO = "/proc/meminfo";
+    public static final int TO_BYTE = 1024;
 
     private FileUtils fileUtils;
     private int userHz = 100; // Shouldn't be hardcoded. See below.
@@ -66,18 +72,28 @@ public String osName() {
     }
 
     public MemoryStats physical() {
-        String totalMemory = fileUtils.runRegexOnFile(TOTAL_MEMORY_PATTERN, "/proc/meminfo");
-        long total = Long.parseLong(totalMemory) * 1024;
-        String freeMemory = fileUtils.runRegexOnFile(FREE_MEMORY_PATTERN, "/proc/meminfo");
-        long free = Long.parseLong(freeMemory) * 1024;
+        String totalMemory = fileUtils.runRegexOnFile(TOTAL_MEMORY_PATTERN, PROC_MEMINFO);
+        long total = Long.parseLong(totalMemory) * TO_BYTE;
+        String freeMemory = fileUtils.runRegexOnFile(FREE_MEMORY_PATTERN, PROC_MEMINFO);
+        long free = Long.parseLong(freeMemory) * TO_BYTE;
+        return new MemoryStats(free, total);
+    }
+
+    public MemoryStats physicalWithBuffersAndCached() {
+        String totalMemory = fileUtils.runRegexOnFile(TOTAL_MEMORY_PATTERN, PROC_MEMINFO);
+        long total = Long.parseLong(totalMemory) * TO_BYTE;
+        String freeMemory = fileUtils.runRegexOnFile(FREE_MEMORY_PATTERN, PROC_MEMINFO);
+        String buffers = fileUtils.runRegexOnFile(BUFFERS_PATTERN, PROC_MEMINFO);
+        String cached = fileUtils.runRegexOnFile(CACHED_PATTERN, PROC_MEMINFO);
+        long free = (Long.parseLong(freeMemory) + Long.parseLong(buffers) + Long.parseLong(cached)) * TO_BYTE;
         return new MemoryStats(free, total);
     }
 
     public MemoryStats swap() {
-        String totalMemory = fileUtils.runRegexOnFile(TOTAL_SWAP_PATTERN, "/proc/meminfo");
-        long total = Long.parseLong(totalMemory) * 1024;
-        String freeMemory = fileUtils.runRegexOnFile(FREE_SWAP_PATTERN, "/proc/meminfo");
-        long free = Long.parseLong(freeMemory) * 1024;
+        String totalMemory = fileUtils.runRegexOnFile(TOTAL_SWAP_PATTERN, PROC_MEMINFO);
+        long total = Long.parseLong(totalMemory) * TO_BYTE;
+        String freeMemory = fileUtils.runRegexOnFile(FREE_SWAP_PATTERN, PROC_MEMINFO);
+        long free = Long.parseLong(freeMemory) * TO_BYTE;
         return new MemoryStats(free, total);
     }
 

diff --git a/src/main/java/com/jezhumble/javasysmon/MacOsXMonitor.java b/src/main/java/com/jezhumble/javasysmon/MacOsXMonitor.java
@@ -28,6 +28,7 @@ public String osName() {
     public native int currentPid();
     public native CpuTimes cpuTimes();
     public native MemoryStats physical();
+    public MemoryStats physicalWithBuffersAndCached(){ throw new UnsupportedOperationException("No implementation for " + osName()); }
     public native MemoryStats swap();
     public native ProcessInfo[] processTable();
     public native void killProcess(int pid);

diff --git a/src/main/java/com/jezhumble/javasysmon/Monitor.java b/src/main/java/com/jezhumble/javasysmon/Monitor.java
@@ -60,6 +60,14 @@ public interface Monitor {
      */
     public MemoryStats physical();
 
+    /**
+     * Gets the physical memory installed, and the amount free + buffers/cache.
+     *
+     * @return An object containing the amount of physical
+     * memory installed, and the amount free + buffers/cache.
+     */
+    public MemoryStats physicalWithBuffersAndCached();
+
     /**
      * Gets the amount of swap available to the operating system,
      * and the amount that is free.

diff --git a/src/main/java/com/jezhumble/javasysmon/NullMonitor.java b/src/main/java/com/jezhumble/javasysmon/NullMonitor.java
@@ -26,6 +26,10 @@ public MemoryStats physical() {
         return null;
     }
 
+    public MemoryStats physicalWithBuffersAndCached(){
+        return null;
+    }
+
     public MemoryStats swap() {
         return null;
     }

diff --git a/src/main/java/com/jezhumble/javasysmon/SolarisMonitor.java b/src/main/java/com/jezhumble/javasysmon/SolarisMonitor.java
@@ -50,6 +50,7 @@ public ProcessInfo[] processTable() {
     public native int currentPid();
     public native CpuTimes cpuTimes();
     public native MemoryStats physical();
+    public MemoryStats physicalWithBuffersAndCached(){ throw new UnsupportedOperationException("No implementation for " + osName()); }
     public native MemoryStats swap();
     public native void killProcess(int pid);
 }
diff --git a/src/main/java/com/jezhumble/javasysmon/WindowsMonitor.java b/src/main/java/com/jezhumble/javasysmon/WindowsMonitor.java
@@ -31,6 +31,7 @@ public String osName() {
     public native long uptimeInSeconds();
     public native CpuTimes cpuTimes();
     public native MemoryStats physical();
+    public MemoryStats physicalWithBuffersAndCached(){ throw new UnsupportedOperationException("No implementation for " + osName()); }
     public native MemoryStats swap();
     public native ProcessInfo[] processTable();
     public native void killProcess(int pid);

diff --git a/src/test/java/com/jezhumble/javasysmon/LinuxMonitorTest.java b/src/test/java/com/jezhumble/javasysmon/LinuxMonitorTest.java
@@ -19,6 +19,12 @@ public void testShouldRetrieveFreeMemory() {
         Assert.assertEquals((long)195608, freeMemory/1024);
     }
 
+    public void testShouldRetrieveFreeMemoryWithCachedAndBuffer() {
+        LinuxMonitor monitor = new LinuxMonitor(new StubFileUtils());
+        final long freeMemory = monitor.physicalWithBuffersAndCached().getFreeBytes();
+        Assert.assertEquals((long)196038, freeMemory/1024);
+    }
+
     public void testShouldRetrieveTotalSwap() {
         LinuxMonitor monitor = new LinuxMonitor(new StubFileUtils());
         final long totalSwap = monitor.swap().getTotalBytes();

diff --git a/src/test/resources/test_meminfo b/src/test/resources/test_meminfo
@@ -1,7 +1,7 @@
 MemTotal:       368640 kB
 MemFree:        195608 kB
-Buffers:             0 kB
-Cached:              0 kB
+Buffers:           100 kB
+Cached:            330 kB
 SwapCached:          0 kB
 Active:              0 kB
 Inactive:            0 kB