Remove duplicate function types from type section.

src/de/inetsoftware/jwebassembly/binary/BinaryModuleWriter.java

@@ -26,14 +26,13 @@ import java.util.Map;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
-import de.inetsoftware.classparser.MethodInfo;
 import de.inetsoftware.jwebassembly.WasmException;
-import de.inetsoftware.jwebassembly.module.WasmBlockOperator;
 import de.inetsoftware.jwebassembly.module.FunctionName;
 import de.inetsoftware.jwebassembly.module.ModuleWriter;
 import de.inetsoftware.jwebassembly.module.NumericOperator;
 import de.inetsoftware.jwebassembly.module.ValueType;
 import de.inetsoftware.jwebassembly.module.ValueTypeConvertion;
+import de.inetsoftware.jwebassembly.module.WasmBlockOperator;
 
 /**
  * Module Writer for binary format. http://webassembly.org/docs/binary-encoding/
@@ -58,7 +57,7 @@ public class BinaryModuleWriter extends ModuleWriter implements InstructionOpcod
 
     private Map<String, String>         exports             = new LinkedHashMap<>();
 
-    private Map<String, ImportEntry> imports             = new LinkedHashMap<>();
+    private Map<String, ImportFunction> imports             = new LinkedHashMap<>();
 
     private Function                    function;
 
@@ -132,16 +131,15 @@ public class BinaryModuleWriter extends ModuleWriter implements InstructionOpcod
         if( count > 0 ) {
             WasmOutputStream stream = new WasmOutputStream();
             stream.writeVaruint32( count );
-            for( ImportEntry entry : imports.values() ) {
+            for( ImportFunction importFunction : imports.values() ) {
-                byte[] bytes = entry.module.getBytes( StandardCharsets.UTF_8 );
+                byte[] bytes = importFunction.module.getBytes( StandardCharsets.UTF_8 );
                 stream.writeVaruint32( bytes.length );
                 stream.write( bytes );
-                bytes = entry.name.getBytes( StandardCharsets.UTF_8 );
+                bytes = importFunction.name.getBytes( StandardCharsets.UTF_8 );
                 stream.writeVaruint32( bytes.length );
                 stream.write( bytes );
                 stream.writeVaruint32( ExternalKind.Function.ordinal() );
-                int typeIdx = 0; //TODO
+                stream.writeVaruint32( importFunction.typeId );
-                stream.writeVaruint32( typeIdx );
             }
             wasm.writeSection( SectionType.Import, stream, null );
         }
@@ -212,7 +210,10 @@ public class BinaryModuleWriter extends ModuleWriter implements InstructionOpcod
     @Override
     protected void prepareFunction( FunctionName name, String importModule, String importName ) {
         if( importName != null ) {
-            imports.put( name.signatureName, new ImportEntry(importModule, importName) );
+            ImportFunction importFunction;
+            function = importFunction = new ImportFunction(importModule, importName);
+            imports.put( name.signatureName, importFunction );
+            functionType = new FunctionType();
         } else {
             functions.put( name.signatureName, new Function() );
         }
@@ -226,7 +227,7 @@ public class BinaryModuleWriter extends ModuleWriter implements InstructionOpcod
         // initialize the function index IDs
         // https://github.com/WebAssembly/design/blob/master/Modules.md#function-index-space
         int id = 0;
-        for( ImportEntry entry : imports.values() ) {
+        for( ImportFunction entry : imports.values() ) {
             entry.id = id++;
         }
         for( Function function : functions.values() ) {
@@ -272,9 +273,12 @@ public class BinaryModuleWriter extends ModuleWriter implements InstructionOpcod
      */
     @Override
     protected void writeMethodFinish( List<ValueType> locals ) throws IOException {
-        // TODO optimize and search for duplicates
+        int typeId = functionTypes.indexOf( functionType );
-        function.typeId = functionTypes.size();
+        if( typeId < 0 ) {
+            typeId = functionTypes.size();
             functionTypes.add( functionType );
+        }
+        function.typeId = typeId;
 
         
         WasmOutputStream localsStream = new WasmOutputStream();
@@ -656,7 +660,7 @@ public class BinaryModuleWriter extends ModuleWriter implements InstructionOpcod
         if( func != null ) {
             id = func.id;
         } else {
-            ImportEntry entry = imports.get( name );
+            ImportFunction entry = imports.get( name );
             if( entry != null ) {
                 id = entry.id;
             } else {

src/de/inetsoftware/jwebassembly/binary/FunctionType.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Volker Berlin (i-net software)
+ * Copyright 2017 - 2018 Volker Berlin (i-net software)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +17,7 @@ package de.inetsoftware.jwebassembly.binary;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Objects;
 
 import de.inetsoftware.jwebassembly.module.ValueType;
 
@@ -27,7 +28,30 @@ import de.inetsoftware.jwebassembly.module.ValueType;
  */
 class FunctionType {
 
-    List<ValueType> params = new ArrayList<>();
+    final List<ValueType> params = new ArrayList<>();
 
     ValueType             result;                    // Java has only one return parameter
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public int hashCode() {
+        return params.hashCode() + 31 * Objects.hashCode( result );
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public boolean equals( Object obj ) {
+        if( obj == this ) {
+            return true;
+        }
+        if( obj == null || obj.getClass() != getClass() ) {
+            return false;
+        }
+        FunctionType type = (FunctionType)obj;
+        return Objects.equals( params, type.params ) && Objects.equals( result, type.result );
+    }
 }

src/de/inetsoftware/jwebassembly/binary/ImportFunction.java

@@ -20,15 +20,13 @@ package de.inetsoftware.jwebassembly.binary;
  * 
  * @author Volker Berlin
  */
-class ImportEntry {
+class ImportFunction extends Function {
 
     final String module;
 
     final String name;
 
-    int id;
+    ImportFunction( String module, String name ) {
-
-    public ImportEntry( String module, String name ) {
         this.module = module;
         this.name = name;
     }