Java Utililty Methods Memory

List of utility methods to do Memory

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Description

The list of methods to do Memory are organized into topic(s).

Method

voidremoveSliceFromMemory(String schemaName, String cubeName, String loadName)
remove Slice From Memory 
voidreportMemory()
report Memory

Runtime runtime = Runtime.getRuntime();
long mb = 1024 * 1024;
long used = runtime.totalMemory() - runtime.freeMemory();
System.out.printf("......................... memory in use: %d MB .........................%n", used / mb);

StringreportMemory(double val)
report Memory

val /= 1024;
return String.format(" %.4f KB | %.4f MB | %.4f GB", val, val / 1024, val / 1024 / 1024);

StringsimpleMemory()
Return the memory in a simple format. 

StringBuilder memory = new StringBuilder();
Runtime runtime = Runtime.getRuntime();
long maxMemory = runtime.maxMemory();
long totalMemory = runtime.totalMemory();
long freeMemory = runtime.freeMemory();
long usedMemory = totalMemory - freeMemory;
memory.append(toSimpleBytes(usedMemory));
memory.append("/");
...

booleantestMemory(long bytesToTest)
test Memory

System.gc();
if (System.getProperties().getProperty("os.name").startsWith("Windows")) {
    Runtime r = Runtime.getRuntime();
    long avail = r.maxMemory() - r.totalMemory() + r.freeMemory();
    return (avail >= bytesToTest);
int MEGABYTE = 1048576;
int maximumMeg = (int) Math.ceil(bytesToTest / (double) MEGABYTE);
...

voidthrowOutOfMemoryError()
throw Out Of Memory Error

throw new OutOfMemoryError("java");

voidunlimitMemory()
unlimit Memory

try {
    String[] cmd = { "/bin/sh", "-c", "ulimit -s unlimited" };
    Process proc = Runtime.getRuntime().exec(cmd);
    proc.waitFor();
} catch (Exception e) {
    System.err.println("Wrong");

voidwaitForMemory(double memory)
Wait till the given requested amount of MegaBytes is free in memory  

long memoryInBytes = ConvertMegaByteToByte(memory);
while (Runtime.getRuntime().freeMemory() < memoryInBytes) {
    System.gc();
    try {
        Thread.sleep(500);
    } catch (InterruptedException e1) {
        e1.printStackTrace();

voidwriteMemory()
write Memory

Runtime rt = Runtime.getRuntime();
System.out.println("Total " + rt.totalMemory() + "\tMax " + rt.maxMemory() + "\tFree " + rt.freeMemory());