package sun.management;

import java.lang.management.GarbageCollectorMXBean;

import java.lang.management.MemoryUsage;

import javax.management.openmbean.OpenType;

import javax.management.openmbean.SimpleType;

import javax.management.openmbean.TabularType;

import javax.management.openmbean.TabularData;

import javax.management.openmbean.TabularDataSupport;

import javax.management.openmbean.CompositeType;

import javax.management.openmbean.CompositeData;

import javax.management.openmbean.CompositeDataSupport;

import javax.management.openmbean.OpenDataException;

import com.sun.management.GcInfo;

public class GcInfoBuilder {

private final GarbageCollectorMXBean gc;

private final String[] poolNames;

private String[] allItemNames;

// GC-specific composite type:

// Each GarbageCollectorMXBean may have different GC-specific attributes

// the CompositeType for the GcInfo could be different.

private CompositeType gcInfoCompositeType;

// GC-specific items

private final int gcExtItemCount;

private final String[] gcExtItemNames;

private final String[] gcExtItemDescs;

private final char[] gcExtItemTypes;

GcInfoBuilder(GarbageCollectorMXBean gc, String[] poolNames) {

this.gc = gc;

this.poolNames = poolNames;

this.gcExtItemCount = getNumGcExtAttributes(gc);

this.gcExtItemNames = new String[gcExtItemCount];

this.gcExtItemDescs = new String[gcExtItemCount];

this.gcExtItemTypes = new char[gcExtItemCount];

// Fill the information about extension attributes

fillGcAttributeInfo(gc, gcExtItemCount, gcExtItemNames,

gcExtItemTypes, gcExtItemDescs);

// lazily build the CompositeType for the GcInfo

// including the GC-specific extension attributes

this.gcInfoCompositeType = null;

}

GcInfo getLastGcInfo() {

MemoryUsage[] usageBeforeGC = new MemoryUsage[poolNames.length];

MemoryUsage[] usageAfterGC = new MemoryUsage[poolNames.length];

Object[] values = new Object[gcExtItemCount];

return getLastGcInfo0(gc, gcExtItemCount, values, gcExtItemTypes,

usageBeforeGC, usageAfterGC);

}

public String[] getPoolNames() {

return poolNames;

}

int getGcExtItemCount() {

return gcExtItemCount;

}

// Returns the CompositeType for the GcInfo including

// the extension attributes

synchronized CompositeType getGcInfoCompositeType() {

if (gcInfoCompositeType != null)

return gcInfoCompositeType;

// First, fill with the attributes in the GcInfo

String[] gcInfoItemNames = GcInfoCompositeData.getBaseGcInfoItemNames();

OpenType[] gcInfoItemTypes = GcInfoCompositeData.getBaseGcInfoItemTypes();

int numGcInfoItems = gcInfoItemNames.length;

int itemCount = numGcInfoItems + gcExtItemCount;

allItemNames = new String[itemCount];

String[] allItemDescs = new String[itemCount];

OpenType[] allItemTypes = new OpenType[itemCount];

System.arraycopy(gcInfoItemNames, 0, allItemNames, 0, numGcInfoItems);

System.arraycopy(gcInfoItemNames, 0, allItemDescs, 0, numGcInfoItems);

System.arraycopy(gcInfoItemTypes, 0, allItemTypes, 0, numGcInfoItems);

// Then fill with the extension GC-specific attributes, if any.

if (gcExtItemCount > 0) {

fillGcAttributeInfo(gc, gcExtItemCount, gcExtItemNames,

gcExtItemTypes, gcExtItemDescs);

System.arraycopy(gcExtItemNames, 0, allItemNames,

numGcInfoItems, gcExtItemCount);

System.arraycopy(gcExtItemDescs, 0, allItemDescs,

numGcInfoItems, gcExtItemCount);

for (int i = numGcInfoItems, j = 0; j < gcExtItemCount; i++, j++) {

switch (gcExtItemTypes[j]) {

case 'Z':

allItemTypes[i] = SimpleType.BOOLEAN;

break;

case 'B':

allItemTypes[i] = SimpleType.BYTE;

break;

case 'C':

allItemTypes[i] = SimpleType.CHARACTER;

break;

case 'S':

allItemTypes[i] = SimpleType.SHORT;

break;

case 'I':

allItemTypes[i] = SimpleType.INTEGER;

break;

case 'J':

allItemTypes[i] = SimpleType.LONG;

break;

case 'F':

allItemTypes[i] = SimpleType.FLOAT;

break;

case 'D':

allItemTypes[i] = SimpleType.DOUBLE;

break;

default:

throw new AssertionError(

"Unsupported type [" + gcExtItemTypes[i] + "]");

}

}

}

CompositeType gict = null;

try {

final String typeName =

"sun.management." + gc.getName() + ".GcInfoCompositeType";

gict = new CompositeType(typeName,

"CompositeType for GC info for " +

gc.getName(),

allItemNames,

allItemDescs,

allItemTypes);

} catch (OpenDataException e) {

// shouldn't reach here

throw Util.newException(e);

}

gcInfoCompositeType = gict;

return gcInfoCompositeType;

}

synchronized String[] getItemNames() {

if (allItemNames == null) {

// initialize when forming the composite type

getGcInfoCompositeType();

}

return allItemNames;

}

// Retrieve information about extension attributes

private native int getNumGcExtAttributes(GarbageCollectorMXBean gc);

private native void fillGcAttributeInfo(GarbageCollectorMXBean gc,

int numAttributes,

String[] attributeNames,

char[] types,

String[] descriptions);

/**

private native GcInfo getLastGcInfo0(GarbageCollectorMXBean gc,

int numExtAtts,

Object[] extAttValues,

char[] extAttTypes,

MemoryUsage[] before,

MemoryUsage[] after);

}