Improve Writer's API for serializable objects

- Fix reference counting for serializable objects

Author: marcospassos

Diff for: src/main/java/com/marcospassos/phpserializer/Writer.java

@@ -2,6 +2,9 @@
 package com.marcospassos.phpserializer;
 
 import java.lang.reflect.Modifier;
+import java.util.function.Consumer;
+import com.marcospassos.phpserializer.state.FinishedState;
+import com.marcospassos.phpserializer.state.WritingSerializableObjectState;
 import com.marcospassos.phpserializer.state.WritingValueState;
 
 /**
@@ -18,14 +21,16 @@ public class Writer
     private StringBuffer buffer;
 
     /**
-     * The current state of the writer.
+     * The reference counter.
      */
-    private WriterState state;
+    private int pointer = 1;
 
     /**
-     * The reference counter.
+     * The current state of the writer.
      */
-    private int pointer = 1;
+    private WriterState state;
+
+    private Writer subWriter;
 
     /**
      * Creates a new writer using an internal buffer.
@@ -60,21 +65,39 @@ public String getResult()
      * Writes a custom serialized object to the buffer.
      *
      * @param className The fully-qualified name of the class.
-     * @param data The serialized data.
+     *
+     * @return A writer to be used to custom write the serializable object.
      */
-    public void writeObject(String className, String data)
+    public Writer writeSerializableObjectStart(String className)
     {
-        setState(state.value());
+        setState(state.serializableBegin());
 
         buffer.append("C:");
         buffer.append(className.length());
         buffer.append(":\"");
         buffer.append(className);
         buffer.append("\":");
+
+        subWriter = new Writer();
+
+        return subWriter;
+    }
+
+    void writeSerializableObjectEnd() {
+        setState(state.serializableEnd());
+
+        if (!(subWriter.state instanceof FinishedState)) {
+            throw new IllegalStateException();
+        }
+
+        String data = subWriter.getResult();
+
         buffer.append(data.length());
         buffer.append(":{");
         buffer.append(data);
         buffer.append("}");
+
+        pointer += subWriter.getPointer();
     }
 
     /**
@@ -336,7 +359,7 @@ public int getPointer()
      *
      * @param state The new state.
      */
-    private void setState(WriterState state)
+    protected void setState(WriterState state)
     {
         if (state.isReferable()) {
             pointer++;

Diff for: src/main/java/com/marcospassos/phpserializer/WriterState.java

@@ -18,6 +18,28 @@ public interface WriterState
      */
     boolean isReferable();
 
+    /**
+     * Returns the new state generated as a result of transitions from the
+     * current state to the new state.
+     *
+     * @return WriterState The new state.
+     *
+     * @throws IllegalStateException if the current state does not allow the
+     * transition to the new state.
+     */
+    WriterState serializableBegin();
+
+    /**
+     * Returns the new state generated as a result of transitions from the
+     * current state to the new state.
+     *
+     * @return WriterState The new state.
+     *
+     * @throws IllegalStateException if the current state does not allow the
+     * transition to the new state.
+     */
+    WriterState serializableEnd();
+
     /**
      * Returns the new state generated as a result of transitions from the
      * current state to the new state.

Diff for: src/main/java/com/marcospassos/phpserializer/state/AbstractState.java

@@ -13,8 +13,18 @@
  * @author Marcos Passos
  * @since 1.0
  */
-public abstract class AbstractState implements WriterState
+abstract class AbstractState implements WriterState
 {
+    public WriterState serializableBegin()
+    {
+        throw new IllegalStateException();
+    }
+
+    public WriterState serializableEnd()
+    {
+        throw new IllegalStateException();
+    }
+
     public WriterState objectBegin()
     {
         throw new IllegalStateException();

Diff for: src/main/java/com/marcospassos/phpserializer/state/WritingSerializableObjectState.java

@@ -0,0 +1,40 @@
+
+package com.marcospassos.phpserializer.state;
+
+import com.marcospassos.phpserializer.WriterState;
+
+/**
+ * Represents the state of the writer while writing an object.
+ *
+ * @author Marcos Passos
+ * @since 1.0
+ */
+public class WritingSerializableObjectState extends AbstractState
+{
+    /**
+     * The parent state.
+     */
+    WriterState parent;
+
+    /**
+     * Creates a new state from the specified parent state.
+     *
+     * @param parent The parent state.
+     */
+    public WritingSerializableObjectState(WriterState parent)
+    {
+        this.parent = parent;
+    }
+
+    @Override
+    public boolean isReferable()
+    {
+        return false;
+    }
+
+    @Override
+    public WriterState serializableEnd()
+    {
+        return parent;
+    }
+}

Diff for: src/main/java/com/marcospassos/phpserializer/state/WritingValueState.java

@@ -40,6 +40,12 @@ public boolean isReferable()
         return true;
     }
 
+    @Override
+    public WriterState serializableBegin()
+    {
+        return new WritingSerializableObjectState(parent);
+    }
+
     @Override
     public WriterState objectBegin()
     {

Diff for: src/test/java/com/marcospassos/phpserializer/WriterTest.java

@@ -39,9 +39,25 @@ public void writeObject() throws Exception
     public void writeSerializableObject() throws Exception
     {
         Writer writer = new Writer();
-        writer.writeObject("Foo", "i:1");
+        Writer objectWriter = writer.writeSerializableObjectStart("Foo");
 
-        assertEquals("C:3:\"Foo\":3:{i:1}", writer.getResult());
+        objectWriter.writeArrayStart(1);
+        objectWriter.writeKey(0);
+        objectWriter.writeString("bar");
+        objectWriter.writeArrayEnd();
+
+        writer.writeSerializableObjectEnd();
+
+        assertEquals("C:3:\"Foo\":20:{a:1:{i:0;s:3:\"bar\";}}", writer.getResult());
+        assertEquals(3, writer.getPointer());
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void writeSerializableObjectEndFailsIfNothingIsWritten() throws Exception
+    {
+        Writer writer = new Writer();
+        writer.writeSerializableObjectStart("Foo");
+        writer.writeSerializableObjectEnd();
     }
 
     @Test

Diff for: src/test/java/com/marcospassos/phpserializer/state/EndStateTest.java

@@ -10,7 +10,6 @@
  */
 public class EndStateTest
 {
-
     private FinishedState state = new FinishedState();
 
     @Test
@@ -37,6 +36,18 @@ public void objectEndIsNotAllowed() throws Exception
         state.objectEnd();
     }
 
+    @Test(expected = IllegalStateException.class)
+    public void serializableObjectBeginIsNotAllowed() throws Exception
+    {
+        state.serializableBegin();
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void serializableObjectEndIsNotAllowed() throws Exception
+    {
+        state.serializableEnd();
+    }
+
     @Test(expected = IllegalStateException.class)
     public void propertyIsNotAllowed() throws Exception
     {

Diff for: src/test/java/com/marcospassos/phpserializer/state/WritingArrayStateTest.java

@@ -15,7 +15,6 @@
  */
 public class WritingArrayStateTest
 {
-
     private WritingArrayState state;
     private WriterState parent;
 
@@ -50,6 +49,18 @@ public void objectEndIsNotAllowed() throws Exception
         state.objectEnd();
     }
 
+    @Test(expected = IllegalStateException.class)
+    public void serializableObjectBeginIsNotAllowed() throws Exception
+    {
+        state.serializableBegin();
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void serializableObjectEndIsNotAllowed() throws Exception
+    {
+        state.serializableEnd();
+    }
+
     @Test(expected = IllegalStateException.class)
     public void propertyIsNotAllowed() throws Exception
     {

Diff for: src/test/java/com/marcospassos/phpserializer/state/WritingObjectStateTest.java

@@ -15,7 +15,6 @@
  */
 public class WritingObjectStateTest
 {
-
     private WritingObjectState state;
     private WriterState parent;
 
@@ -56,6 +55,18 @@ public void propertyIsAllowed() throws Exception
         assertTrue(state.property() instanceof WritingValueState);
     }
 
+    @Test(expected = IllegalStateException.class)
+    public void serializableObjectBeginIsNotAllowed() throws Exception
+    {
+        state.serializableBegin();
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void serializableObjectEndIsNotAllowed() throws Exception
+    {
+        state.serializableEnd();
+    }
+
     @Test(expected = IllegalStateException.class)
     public void arrayBeginIsNotAllowed() throws Exception
     {

Diff for: src/test/java/com/marcospassos/phpserializer/state/WritingSerializableObjectStateTest.java

@@ -0,0 +1,87 @@
+package com.marcospassos.phpserializer.state;
+
+import com.marcospassos.phpserializer.WriterState;
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.mock;
+
+/**
+ * @author Marcos Passos
+ * @since 1.0
+ */
+public class WritingSerializableObjectStateTest
+{
+    private WritingSerializableObjectState state;
+    private WriterState parent;
+
+    @Before
+    public void setUp() throws Exception
+    {
+        parent = mock(WriterState.class);
+        state = new WritingSerializableObjectState(parent);
+    }
+
+    @Test
+    public void isReferableReturnsFalse() throws Exception
+    {
+        assertFalse(state.isReferable());
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void serializableObjectBeginIsNotAllowed() throws Exception
+    {
+        state.serializableBegin();
+    }
+
+    @Test
+    public void serializableObjectEndIsAllowed() throws Exception
+    {
+        assertSame(parent, state.serializableEnd());
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void valueIsNotAllowed() throws Exception
+    {
+        state.value();
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void objectBeginIsNotAllowed() throws Exception
+    {
+        state.objectBegin();
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void objectEndIsNotAllowed() throws Exception
+    {
+        state.objectEnd();
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void propertyIsNotAllowed() throws Exception
+    {
+        state.property();
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void arrayBeginIsNotAllowed() throws Exception
+    {
+        state.arrayBegin();
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void arrayEndIsNotAllowed() throws Exception
+    {
+        state.arrayEnd();
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void keyIsNotAllowed() throws Exception
+    {
+        state.key();
+    }
+}