src/java.base/share/classes/java/lang/Integer.java

rev 51374 : 8209120: Archive the Integer.IntegerCache
Reviewed-by: jiangli, alanb, plevart

*** 995,1005 ****
       */
  
      private static class IntegerCache {
          static final int low = -128;
          static final int high;
!         static final Integer cache[];
  
          static {
              // high value may be configured by property
              int h = 127;
              String integerCacheHighPropValue =
--- 995,1006 ----
       */
  
      private static class IntegerCache {
          static final int low = -128;
          static final int high;
!         static final Integer[] cache;
!         static Integer[] archivedCache;
  
          static {
              // high value may be configured by property
              int h = 127;
              String integerCacheHighPropValue =
*** 1014,1028 ****
                      // If the property cannot be parsed into an int, ignore it.
                  }
              }
              high = h;
  
!             cache = new Integer[(high - low) + 1];
!             int j = low;
!             for(int k = 0; k < cache.length; k++)
!                 cache[k] = new Integer(j++);
  
              // range [-128, 127] must be interned (JLS7 5.1.7)
              assert IntegerCache.high >= 127;
          }
  
          private IntegerCache() {}
--- 1015,1037 ----
                      // If the property cannot be parsed into an int, ignore it.
                  }
              }
              high = h;
  
!             // Load IntegerCache.archivedCache from archive, if possible
!             VM.initializeFromArchive(IntegerCache.class);
!             int size = (high - low) + 1;
  
+             // Use the archived cache if it exists and is large enough
+             if (archivedCache == null || size > archivedCache.length) {
+                 Integer[] c = new Integer[size];
+                 int j = low;
+                 for(int k = 0; k < c.length; k++)
+                     c[k] = new Integer(j++);
+                 archivedCache = c;
+             }
+             cache = archivedCache;
              // range [-128, 127] must be interned (JLS7 5.1.7)
              assert IntegerCache.high >= 127;
          }
  
          private IntegerCache() {}