--- /dev/null
+package org.apache.lucene.util;
+
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import java.lang.reflect.*;
+import java.text.DecimalFormat;
+import java.util.*;
+
+/**
+ * Estimates the size of a given Object using a given MemoryModel for primitive
+ * size information.
+ *
+ * Resource Usage:
+ *
+ * Internally uses a Map to temporally hold a reference to every
+ * object seen.
+ *
+ * If checkInterned, all Strings checked will be interned, but those
+ * that were not already interned will be released for GC when the
+ * estimate is complete.
+ *
+ * @lucene.internal
+ */
+public final class RamUsageEstimator {
+
+ public final static int NUM_BYTES_SHORT = 2;
+ public final static int NUM_BYTES_INT = 4;
+ public final static int NUM_BYTES_LONG = 8;
+ public final static int NUM_BYTES_FLOAT = 4;
+ public final static int NUM_BYTES_DOUBLE = 8;
+ public final static int NUM_BYTES_CHAR = 2;
+ public final static int NUM_BYTES_OBJECT_HEADER = 8;
+ public final static int NUM_BYTES_OBJECT_REF = Constants.JRE_IS_64BIT ? 8 : 4;
+ public final static int NUM_BYTES_ARRAY_HEADER = NUM_BYTES_OBJECT_HEADER + NUM_BYTES_INT + NUM_BYTES_OBJECT_REF;
+
+ private MemoryModel memoryModel;
+
+ private final Map<Object,Object> seen;
+
+ private int refSize;
+ private int arraySize;
+ private int classSize;
+
+ private boolean checkInterned;
+
+ /**
+ * Constructs this object with an AverageGuessMemoryModel and
+ * checkInterned = true.
+ */
+ public RamUsageEstimator() {
+ this(new AverageGuessMemoryModel());
+ }
+
+ /**
+ * @param checkInterned check if Strings are interned and don't add to size
+ * if they are. Defaults to true but if you know the objects you are checking
+ * won't likely contain many interned Strings, it will be faster to turn off
+ * intern checking.
+ */
+ public RamUsageEstimator(boolean checkInterned) {
+ this(new AverageGuessMemoryModel(), checkInterned);
+ }
+
+ /**
+ * @param memoryModel MemoryModel to use for primitive object sizes.
+ */
+ public RamUsageEstimator(MemoryModel memoryModel) {
+ this(memoryModel, true);
+ }
+
+ /**
+ * @param memoryModel MemoryModel to use for primitive object sizes.
+ * @param checkInterned check if Strings are interned and don't add to size
+ * if they are. Defaults to true but if you know the objects you are checking
+ * won't likely contain many interned Strings, it will be faster to turn off
+ * intern checking.
+ */
+ public RamUsageEstimator(MemoryModel memoryModel, boolean checkInterned) {
+ this.memoryModel = memoryModel;
+ this.checkInterned = checkInterned;
+ // Use Map rather than Set so that we can use an IdentityHashMap - not
+ // seeing an IdentityHashSet
+ seen = new IdentityHashMap<Object,Object>(64);
+ this.refSize = memoryModel.getReferenceSize();
+ this.arraySize = memoryModel.getArraySize();
+ this.classSize = memoryModel.getClassSize();
+ }
+
+ public long estimateRamUsage(Object obj) {
+ long size = size(obj);
+ seen.clear();
+ return size;
+ }
+
+ private long size(Object obj) {
+ if (obj == null) {
+ return 0;
+ }
+ // interned not part of this object
+ if (checkInterned && obj instanceof String
+ && obj == ((String) obj).intern()) { // interned string will be eligible
+ // for GC on
+ // estimateRamUsage(Object) return
+ return 0;
+ }
+
+ // skip if we have seen before
+ if (seen.containsKey(obj)) {
+ return 0;
+ }
+
+ // add to seen
+ seen.put(obj, null);
+
+ Class<?> clazz = obj.getClass();
+ if (clazz.isArray()) {
+ return sizeOfArray(obj);
+ }
+
+ long size = 0;
+
+ // walk type hierarchy
+ while (clazz != null) {
+ Field[] fields = clazz.getDeclaredFields();
+ for (int i = 0; i < fields.length; i++) {
+ if (Modifier.isStatic(fields[i].getModifiers())) {
+ continue;
+ }
+
+ if (fields[i].getType().isPrimitive()) {
+ size += memoryModel.getPrimitiveSize(fields[i].getType());
+ } else {
+ size += refSize;
+ fields[i].setAccessible(true);
+ try {
+ Object value = fields[i].get(obj);
+ if (value != null) {
+ size += size(value);
+ }
+ } catch (IllegalAccessException ex) {
+ // ignore for now?
+ }
+ }
+
+ }
+ clazz = clazz.getSuperclass();
+ }
+ size += classSize;
+ return size;
+ }
+
+ private long sizeOfArray(Object obj) {
+ int len = Array.getLength(obj);
+ if (len == 0) {
+ return 0;
+ }
+ long size = arraySize;
+ Class<?> arrayElementClazz = obj.getClass().getComponentType();
+ if (arrayElementClazz.isPrimitive()) {
+ size += len * memoryModel.getPrimitiveSize(arrayElementClazz);
+ } else {
+ for (int i = 0; i < len; i++) {
+ size += refSize + size(Array.get(obj, i));
+ }
+ }
+
+ return size;
+ }
+
+ private static final long ONE_KB = 1024;
+ private static final long ONE_MB = ONE_KB * ONE_KB;
+ private static final long ONE_GB = ONE_KB * ONE_MB;
+
+ /**
+ * Return good default units based on byte size.
+ */
+ public static String humanReadableUnits(long bytes, DecimalFormat df) {
+ String newSizeAndUnits;
+
+ if (bytes / ONE_GB > 0) {
+ newSizeAndUnits = String.valueOf(df.format((float) bytes / ONE_GB))
+ + " GB";
+ } else if (bytes / ONE_MB > 0) {
+ newSizeAndUnits = String.valueOf(df.format((float) bytes / ONE_MB))
+ + " MB";
+ } else if (bytes / ONE_KB > 0) {
+ newSizeAndUnits = String.valueOf(df.format((float) bytes / ONE_KB))
+ + " KB";
+ } else {
+ newSizeAndUnits = String.valueOf(bytes) + " bytes";
+ }
+
+ return newSizeAndUnits;
+ }
+}
fnp / pylucene.git / blobdiff