Merge pull request #80 from maxmind/greg/cache-value-class

Add cache value class

Author: horgh

src/main/java/com/maxmind/db/CHMCache.java

@@ -13,7 +13,7 @@ public class CHMCache implements NodeCache {
     private static final int DEFAULT_CAPACITY = 4096;
 
     private final int capacity;
-    private final ConcurrentHashMap<CacheKey, Object> cache;
+    private final ConcurrentHashMap<CacheKey, DecodedValue> cache;
     private boolean cacheFull = false;
 
     public CHMCache() {
@@ -26,8 +26,8 @@ public CHMCache(int capacity) {
     }
 
     @Override
-    public Object get(CacheKey key, Loader loader) throws IOException {
-        Object value = cache.get(key);
+    public DecodedValue get(CacheKey key, Loader loader) throws IOException {
+        DecodedValue value = cache.get(key);
         if (value == null) {
             value = loader.load(key);
             if (!cacheFull) {

src/main/java/com/maxmind/db/CacheKey.java

@@ -44,14 +44,9 @@ public boolean equals(Object o) {
         }
 
         if (this.type == null) {
-            if (other.type != null) {
-                return false;
-            }
-        } else if (!this.type.equals(other.type)) {
-            return false;
+            return other.type == null;
         }
-
-        return true;
+        return this.type.equals(other.type);
     }
 
     @Override

src/main/java/com/maxmind/db/DecodedValue.java

@@ -0,0 +1,13 @@
+package com.maxmind.db;
+
+public final class DecodedValue {
+     final Object value;
+
+    DecodedValue(Object value) {
+        this.value = value;
+    }
+
+    Object getValue() {
+        return value;
+    }
+}

src/main/java/com/maxmind/db/Decoder.java

@@ -2,7 +2,6 @@
 
 import java.io.IOException;
 import java.lang.annotation.Annotation;
-import java.lang.reflect.Array;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.ParameterizedType;
@@ -74,10 +73,10 @@ public <T> T decode(int offset, Class<T> cls) throws IOException {
         }
 
         this.buffer.position(offset);
-        return cls.cast(decode(cls, null));
+        return cls.cast(decode(cls, null).getValue());
     }
 
-    private <T> Object decode(CacheKey<T> key) throws IOException {
+    private <T> DecodedValue decode(CacheKey<T> key) throws IOException {
         int offset = key.getOffset();
         if (offset >= this.buffer.capacity()) {
             throw new InvalidDatabaseException(
@@ -90,7 +89,7 @@ private <T> Object decode(CacheKey<T> key) throws IOException {
         return decode(cls, key.getType());
     }
 
-    private <T> Object decode(Class<T> cls, java.lang.reflect.Type genericType)
+    private <T> DecodedValue decode(Class<T> cls, java.lang.reflect.Type genericType)
             throws IOException {
         int ctrlByte = 0xFF & this.buffer.get();
 
@@ -107,14 +106,14 @@ private <T> Object decode(Class<T> cls, java.lang.reflect.Type genericType)
 
             // for unit testing
             if (this.POINTER_TEST_HACK) {
-                return pointer;
+                return new DecodedValue(pointer);
             }
 
             int targetOffset = (int) pointer;
             int position = buffer.position();
 
             CacheKey key = new CacheKey(targetOffset, cls, genericType);
-            Object o = decode(key);
+            DecodedValue o = cache.get(key, cacheLoader);
 
             buffer.position(position);
             return o;
@@ -149,7 +148,7 @@ private <T> Object decode(Class<T> cls, java.lang.reflect.Type genericType)
             }
         }
 
-        return this.decodeByType(type, size, cls, genericType);
+        return new DecodedValue(this.decodeByType(type, size, cls, genericType));
     }
 
     private <T> Object decodeByType(
@@ -284,7 +283,7 @@ private <T, V> List<V> decodeArray(
             Class<V> elementClass
     ) throws IOException {
         if (!List.class.isAssignableFrom(cls) && !cls.equals(Object.class)) {
-            throw new DeserializationException();
+            throw new DeserializationException("Unable to deserialize an array into an " + cls);
         }
 
         List<V> array;
@@ -310,7 +309,7 @@ private <T, V> List<V> decodeArray(
         }
 
         for (int i = 0; i < size; i++) {
-            Object e = this.decode(elementClass, null);
+            Object e = this.decode(elementClass, null).getValue();
             array.add(elementClass.cast(e));
         }
 
@@ -371,8 +370,8 @@ private <T, V> Map<String, V> decodeMapIntoMap(
         }
 
         for (int i = 0; i < size; i++) {
-            String key = (String) this.decode(String.class, null);
-            Object value = this.decode(valueClass, null);
+            String key = (String) this.decode(String.class, null).getValue();
+            Object value = this.decode(valueClass, null).getValue();
             map.put(key, valueClass.cast(value));
         }
 
@@ -418,7 +417,7 @@ private <T> Object decodeMapIntoObject(int size, Class<T> cls)
 
         Object[] parameters = new Object[parameterTypes.length];
         for (int i = 0; i < size; i++) {
-            String key = (String) this.decode(String.class, null);
+            String key = (String) this.decode(String.class, null).getValue();
 
             Integer parameterIndex = parameterIndexes.get(key);
             if (parameterIndex == null) {
@@ -430,7 +429,7 @@ private <T> Object decodeMapIntoObject(int size, Class<T> cls)
             parameters[parameterIndex] = this.decode(
                 parameterTypes[parameterIndex],
                 parameterGenericTypes[parameterIndex]
-            );
+            ).getValue();
         }
 
         try {

src/main/java/com/maxmind/db/NoCache.java

@@ -13,7 +13,7 @@ private NoCache() {
     }
 
     @Override
-    public Object get(CacheKey key, Loader loader) throws IOException {
+    public DecodedValue get(CacheKey key, Loader loader) throws IOException {
         return loader.load(key);
     }
 

src/main/java/com/maxmind/db/NodeCache.java

@@ -5,9 +5,9 @@
 public interface NodeCache {
 
     interface Loader {
-        Object load(CacheKey key) throws IOException;
+        DecodedValue load(CacheKey key) throws IOException;
     }
 
-    Object get(CacheKey key, Loader loader) throws IOException;
+    DecodedValue get(CacheKey key, Loader loader) throws IOException;
 
 }

src/main/java/com/maxmind/db/Reader.java

@@ -154,7 +154,7 @@ public <T> T get(InetAddress ipAddress, Class<T> cls) throws IOException {
      *
      * @param ipAddress the IP address to look up.
      * @return the record for the IP address. If there is no data for the
-     * address, the non-null {@link Record} will still be returned.
+     * address, the non-null {@link DatabaseRecord} will still be returned.
      * @throws IOException if a file I/O error occurs.
      */
     public <T> DatabaseRecord<T> getRecord(InetAddress ipAddress, Class<T> cls)

src/test/java/com/maxmind/db/DecoderTest.java

@@ -3,7 +3,6 @@
 import java.io.File;
 import java.io.IOException;
 import java.io.RandomAccessFile;
-import java.lang.reflect.Array;
 import java.math.BigInteger;
 import java.nio.ByteBuffer;
 import java.nio.MappedByteBuffer;

src/test/java/com/maxmind/db/ReaderTest.java

@@ -659,16 +659,16 @@ public void testCacheKey() {
 
         CacheKey a = new CacheKey(1, cls, getType(cls, 0));
         CacheKey b = new CacheKey(1, cls, getType(cls, 0));
-        assertTrue(a.equals(b));
+        assertEquals(a, b);
 
         CacheKey c = new CacheKey(2, cls, getType(cls, 0));
-        assertFalse(a.equals(c));
+        assertNotEquals(a, c);
 
         CacheKey d = new CacheKey(1, String.class, getType(cls, 0));
-        assertFalse(a.equals(d));
+        assertNotEquals(a, d);
 
         CacheKey e = new CacheKey(1, cls, getType(cls, 1));
-        assertFalse(a.equals(e));
+        assertNotEquals(a, e);
     }
 
     private <T> java.lang.reflect.Type getType(Class<T> cls, int i) {