[to dev/1.1] Avoid calculating shallow size of map

java/common/src/main/java/org/apache/tsfile/utils/RamUsageEstimator.java

@@ -29,9 +29,11 @@
 import java.text.DecimalFormatSymbols;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.IdentityHashMap;
 import java.util.Locale;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 /**
  * This class is copied from apache lucene, version 8.4.0. Estimates the size(memory representation)
@@ -302,6 +304,23 @@ public static long sizeOf(String[] arr) {
   /** Recurse only into immediate descendants. */
   public static final int MAX_DEPTH = 1;
 
+  public static final long SHALLOW_SIZE_OF_HASHMAP =
+      RamUsageEstimator.shallowSizeOfInstance(HashMap.class);
+  public static long SHALLOW_SIZE_OF_HASHMAP_ENTRY;
+  public static final long SHALLOW_SIZE_OF_CONCURRENT_HASHMAP =
+      RamUsageEstimator.shallowSizeOfInstance(ConcurrentHashMap.class);
+  public static long SHALLOW_SIZE_OF_CONCURRENT_HASHMAP_ENTRY;
+
+  static {
+    Map<Integer, Integer> map = new HashMap<>(1);
+    map.put(1, 1);
+    Map.Entry<Integer, Integer> next = map.entrySet().iterator().next();
+    SHALLOW_SIZE_OF_HASHMAP_ENTRY = RamUsageEstimator.shallowSizeOf(next);
+    map = new ConcurrentHashMap<>(map);
+    SHALLOW_SIZE_OF_CONCURRENT_HASHMAP_ENTRY =
+        RamUsageEstimator.shallowSizeOf(map.entrySet().iterator().next());
+  }
+
   /**
    * Returns the size in bytes of a Map object, including sizes of its keys and values, supplying
    * {@link #UNKNOWN_DEFAULT_RAM_BYTES_USED} when object type is not well known. This method
@@ -340,6 +359,21 @@ private static long sizeOfMap(Map<?, ?> map, int depth, long defSize) {
     return alignObjectSize(size);
   }
 
+  public static long sizeOfMapWithKnownShallowSize(
+      Map<?, ?> map, long shallowSizeOfMap, long shallowSizeOfMapEntry) {
+    if (map == null) {
+      return 0;
+    }
+    int depth = 0;
+    long defSize = UNKNOWN_DEFAULT_RAM_BYTES_USED;
+    long size = shallowSizeOfMap + map.size() * shallowSizeOfMapEntry;
+    for (Map.Entry<?, ?> entry : map.entrySet()) {
+      size += sizeOfObject(entry.getKey(), depth, defSize);
+      size += sizeOfObject(entry.getValue(), depth, defSize);
+    }
+    return alignObjectSize(size);
+  }
+
   /**
    * Returns the size in bytes of a Collection object, including sizes of its values, supplying
    * {@link #UNKNOWN_DEFAULT_RAM_BYTES_USED} when object type is not well known. This method

java/tsfile/src/main/java/org/apache/tsfile/write/schema/MeasurementSchema.java

@@ -455,6 +455,9 @@ public void setCompressor(byte compressor) {
   public long ramBytesUsed() {
     return INSTANCE_SIZE
         + RamUsageEstimator.sizeOf(measurementId)
-        + RamUsageEstimator.sizeOfMap(props);
+        + RamUsageEstimator.sizeOfMapWithKnownShallowSize(
+            props,
+            RamUsageEstimator.SHALLOW_SIZE_OF_HASHMAP,
+            RamUsageEstimator.SHALLOW_SIZE_OF_HASHMAP_ENTRY);
   }
 }