From 71a6aa7e711079ad606bd91cd90609575533c77e Mon Sep 17 00:00:00 2001
From: Bruce Eckel <mindviewinc@gmail.com>
Date: Fri, 5 Aug 2016 16:07:30 -0600
Subject: [PATCH] Initial Reasonable JMH example working

---
 .../jmhtests/MapPerformance.java              | 81 +++++++++++++++++++
 .../jmhtests/MapPerformanceJMH.java           | 66 ---------------
 2 files changed, 81 insertions(+), 66 deletions(-)
 create mode 100644 understandingcollections/jmhtests/MapPerformance.java
 delete mode 100644 understandingcollections/jmhtests/MapPerformanceJMH.java

diff --git a/understandingcollections/jmhtests/MapPerformance.java b/understandingcollections/jmhtests/MapPerformance.java
new file mode 100644
index 00000000..7b6bea7b
--- /dev/null
+++ b/understandingcollections/jmhtests/MapPerformance.java
@@ -0,0 +1,81 @@
+// understandingcollections/jmhtests/MapPerformance.java
+// (c)2016 MindView LLC: see Copyright.txt
+// We make no guarantees that this code is fit for any purpose.
+// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
+// Performance differences between Maps
+package understandingcollections.jmhtests;
+import org.openjdk.jmh.annotations.*;
+import org.openjdk.jmh.infra.Blackhole;
+import java.util.*;
+import static java.util.concurrent.TimeUnit.*;
+
+@State(Scope.Thread)
+@Warmup(iterations = 5, time = 1, timeUnit = SECONDS)
+@Measurement(iterations = 5, time = 1, timeUnit = SECONDS)
+@Fork(1)
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(NANOSECONDS)
+public class MapPerformance {
+  private Map<Integer, Integer> map;
+
+  @Param({"hashmap", "treemap", "linkedhashmap",
+    "identityhashmap", "weakhashmap", "hashtable"})
+  private String type;
+
+  private int begin;
+  private int end;
+
+  @Setup
+  public void setup() {
+    switch(type) {
+      case "hashmap":
+        map = new HashMap<>();
+        break;
+      case "treemap":
+        map = new TreeMap<>();
+        break;
+      case "linkedhashmap":
+        map = new LinkedHashMap<>();
+        break;
+      case "identityhashmap":
+        map = new IdentityHashMap<>();
+        break;
+      case "weakhashmap":
+        map = new WeakHashMap<>();
+        break;
+      case "hashtable":
+        map = new Hashtable<>();
+        break;
+      default:
+        throw new IllegalStateException("Unknown " + type);
+    }
+
+    begin = 1;
+    end = 256;
+    for (int i = begin; i < end; i++) {
+      map.put(i, i);
+    }
+  }
+
+  @Benchmark
+  public void get(Blackhole bh) {
+    for (int i = begin; i < end; i++) {
+      bh.consume(map.get(i));
+    }
+  }
+
+  @Benchmark
+  public void put(Blackhole bh) {
+    for (int i = begin; i < end; i++) {
+      bh.consume(map.put(i, i));
+    }
+  }
+
+  @Benchmark
+  public void iterate(Blackhole bh) {
+    Iterator it = map.entrySet().iterator();
+    while(it.hasNext())
+      bh.consume(it.next());
+  }
+
+}
diff --git a/understandingcollections/jmhtests/MapPerformanceJMH.java b/understandingcollections/jmhtests/MapPerformanceJMH.java
deleted file mode 100644
index 2e50d449..00000000
--- a/understandingcollections/jmhtests/MapPerformanceJMH.java
+++ /dev/null
@@ -1,66 +0,0 @@
-// understandingcollections/jmhtests/MapPerformanceJMH.java
-// (c)2016 MindView LLC: see Copyright.txt
-// We make no guarantees that this code is fit for any purpose.
-// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
-// Demonstrates performance differences in Maps
-package understandingcollections.jmhtests;
-import org.openjdk.jmh.annotations.*;
-import org.openjdk.jmh.infra.Blackhole;
-import java.util.*;
-
-@State(Scope.Thread)
-public class MapPerformanceJMH {
-  private Map<Integer, Integer> map;
-
-  @Param({"hashmap", "treemap"})
-  private String type;
-
-  private int begin;
-  private int end;
-
-  @Setup
-  public void setup() {
-    if (type.equals("hashmap")) {
-      map = new HashMap<Integer, Integer>();
-    } else if (type.equals("treemap")) {
-      map = new TreeMap<Integer, Integer>();
-    } else {
-      throw new IllegalStateException("Unknown type: " + type);
-    }
-
-    begin = 1;
-    end = 256;
-    for (int i = begin; i < end; i++) {
-      map.put(i, i);
-    }
-  }
-
-  @Benchmark
-  public void get(Blackhole bh) {
-    for (int i = begin; i < end; i++) {
-      bh.consume(map.get(i));
-    }
-  }
-
-// These are incomplete placeholders from the
-// original MapPerformance.jaava:
-/*  @Benchmark
-  int put() {
-    for(int i = 0; i < loops; i++) {
-      map.clear();
-      for(int j = 0; j < size; j++)
-        map.put(j, j);
-    }
-    return loops * size;
-  }*/
-
-/*  @Benchmark
-  int iterate() {
-    for(int i = 0; i < loops; i ++) {
-      Iterator it = map.entrySet().iterator();
-      while(it.hasNext())
-        it.next();
-    }
-  }*/
-
-}