Add option to print size statistics of generated JS code

core/src/main/java/org/teavm/backend/javascript/JavaScriptTarget.java

@@ -15,12 +15,18 @@
  */
 package org.teavm.backend.javascript;
 
+import com.carrotsearch.hppc.ObjectIntHashMap;
+import com.carrotsearch.hppc.ObjectIntMap;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.io.Writer;
+import java.text.DecimalFormat;
+import java.text.NumberFormat;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
+import java.util.Comparator;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -83,6 +89,9 @@ import org.teavm.vm.spi.RendererListener;
 import org.teavm.vm.spi.TeaVMHostExtension;
 
 public class JavaScriptTarget implements TeaVMTarget, TeaVMJavaScriptHost {
+    private static final NumberFormat STATS_NUM_FORMAT = new DecimalFormat("#,##0");
+    private static final NumberFormat STATS_PERCENT_FORMAT = new DecimalFormat("0.000 %");
+
     private TeaVMTargetController controller;
     private boolean minifying = true;
     private final Map<MethodReference, Generator> methodGenerators = new HashMap<>();
@@ -285,6 +294,7 @@ public class JavaScriptTarget implements TeaVMTarget, TeaVMJavaScriptHost {
             for (RendererListener listener : rendererListeners) {
                 listener.begin(renderer, target);
             }
+            int start = sourceWriter.getOffset();
             sourceWriter.append("\"use strict\";").newLine();
             renderer.renderRuntime();
             renderer.render(clsNodes);
@@ -300,11 +310,46 @@ public class JavaScriptTarget implements TeaVMTarget, TeaVMJavaScriptHost {
             for (RendererListener listener : rendererListeners) {
                 listener.complete();
             }
+            int totalSize = sourceWriter.getOffset() - start;
+            printStats(renderer, totalSize);
         } catch (IOException e) {
             throw new RenderingException("IO Error occured", e);
         }
     }
 
+    private void printStats(Renderer renderer, int totalSize) {
+        if (!Boolean.parseBoolean(System.getProperty("teavm.js.stats", "false"))) {
+            return;
+        }
+
+        System.out.println("Total output size: " + STATS_NUM_FORMAT.format(totalSize));
+        System.out.println("Metadata size: " + getSizeWithPercentage(renderer.getMetadataSize(), totalSize));
+        System.out.println("String pool size: " + getSizeWithPercentage(renderer.getStringPoolSize(), totalSize));
+
+        ObjectIntMap<String> packageSizeMap = new ObjectIntHashMap<>();
+        for (String className : renderer.getClassesInStats()) {
+            String packageName = className.substring(0, className.lastIndexOf('.') + 1);
+            int classSize = renderer.getClassSize(className);
+            packageSizeMap.put(packageName, packageSizeMap.getOrDefault(packageName, 0) + classSize);
+        }
+
+        String[] packageNames = packageSizeMap.keys().toArray(String.class);
+        Arrays.sort(packageNames, Comparator.comparing(p -> -packageSizeMap.getOrDefault(p, 0)));
+        for (String packageName : packageNames) {
+            System.out.println("Package '" + packageName + "' size: "
+                    + getSizeWithPercentage(packageSizeMap.get(packageName), totalSize));
+        }
+    }
+
+    private String getSizeWithPercentage(int size, int totalSize) {
+        return STATS_NUM_FORMAT.format(size) + " (" + STATS_PERCENT_FORMAT.format((double) size / totalSize) + ")";
+    }
+
+    static class PackageNode {
+        String name;
+        Map<String, PackageNode> children = new HashMap<>();
+    }
+
     private List<ClassNode> modelToAst(ListableClassHolderSource classes) {
         AsyncMethodFinder asyncFinder = new AsyncMethodFinder(controller.getDependencyInfo().getCallGraph(),
                 controller.getDiagnostics());

core/src/main/java/org/teavm/backend/javascript/codegen/LocationProvider.java

@@ -19,4 +19,6 @@ public interface LocationProvider {
     int getLine();
 
     int getColumn();
+
+    int getOffset();
 }

core/src/main/java/org/teavm/backend/javascript/codegen/SourceWriter.java

@@ -30,6 +30,7 @@ public class SourceWriter implements Appendable, LocationProvider {
     private final int lineWidth;
     private int column;
     private int line;
+    private int offset;
 
     SourceWriter(NamingStrategy naming, Appendable innerWriter, int lineWidth) {
         this.naming = naming;
@@ -62,6 +63,7 @@ public class SourceWriter implements Appendable, LocationProvider {
             newLine();
         } else {
             column++;
+            offset++;
         }
         return this;
     }
@@ -92,6 +94,7 @@ public class SourceWriter implements Appendable, LocationProvider {
         }
         appendIndent();
         column += end - start;
+        offset += end - start;
         innerWriter.append(csq, start, end);
     }
 
@@ -149,6 +152,7 @@ public class SourceWriter implements Appendable, LocationProvider {
             for (int i = 0; i < indentSize; ++i) {
                 innerWriter.append("    ");
                 column += 4;
+                offset += 4;
             }
             lineStart = false;
         }
@@ -158,6 +162,7 @@ public class SourceWriter implements Appendable, LocationProvider {
         innerWriter.append('\n');
         column = 0;
         ++line;
+        ++offset;
         lineStart = true;
         return this;
     }
@@ -169,6 +174,7 @@ public class SourceWriter implements Appendable, LocationProvider {
             if (!minified) {
                 innerWriter.append(' ');
                 column++;
+                offset++;
             }
         }
         return this;
@@ -185,6 +191,7 @@ public class SourceWriter implements Appendable, LocationProvider {
         if (!minified) {
             innerWriter.append('\n');
             column = 0;
+            ++offset;
             ++line;
             lineStart = true;
         }
@@ -214,4 +221,9 @@ public class SourceWriter implements Appendable, LocationProvider {
     public int getLine() {
         return line;
     }
+
+    @Override
+    public int getOffset() {
+        return offset;
+    }
 }

core/src/main/java/org/teavm/backend/javascript/rendering/Renderer.java

@@ -15,6 +15,8 @@
  */
 package org.teavm.backend.javascript.rendering;
 
+import com.carrotsearch.hppc.ObjectIntHashMap;
+import com.carrotsearch.hppc.ObjectIntMap;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.HashSet;
@@ -66,6 +68,10 @@ public class Renderer implements RenderingManager {
     private RenderingContext context;
     private List<PostponedFieldInitializer> postponedFieldInitializers = new ArrayList<>();
 
+    private ObjectIntMap<String> sizeByClass = new ObjectIntHashMap<>();
+    private int stringPoolSize;
+    private int metadataSize;
+
     public Renderer(SourceWriter writer, Set<MethodReference> asyncMethods, Set<MethodReference> asyncFamilyMethods,
             Diagnostics diagnostics, RenderingContext context) {
         this.naming = context.getNaming();
@@ -79,6 +85,22 @@ public class Renderer implements RenderingManager {
         this.context = context;
     }
 
+    public int getStringPoolSize() {
+        return stringPoolSize;
+    }
+
+    public int getMetadataSize() {
+        return metadataSize;
+    }
+
+    public String[] getClassesInStats() {
+        return sizeByClass.keys().toArray(String.class);
+    }
+
+    public int getClassSize(String className) {
+        return sizeByClass.getOrDefault(className, 0);
+    }
+
     @Override
     public SourceWriter getWriter() {
         return writer;
@@ -133,6 +155,7 @@ public class Renderer implements RenderingManager {
             return;
         }
         try {
+            int start = writer.getOffset();
             writer.append("$rt_stringPool([");
             for (int i = 0; i < context.getStringPool().size(); ++i) {
                 if (i > 0) {
@@ -141,6 +164,7 @@ public class Renderer implements RenderingManager {
                 writer.append('"').append(RenderingUtil.escapeString(context.getStringPool().get(i))).append('"');
             }
             writer.append("]);").newLine();
+            stringPoolSize = writer.getOffset() - start;
         } catch (IOException e) {
             throw new RenderingException("IO error", e);
         }
@@ -149,14 +173,21 @@ public class Renderer implements RenderingManager {
     public void renderStringConstants() throws RenderingException {
         try {
             for (PostponedFieldInitializer initializer : postponedFieldInitializers) {
+                int start = writer.getOffset();
                 writer.appendStaticField(initializer.field).ws().append("=").ws()
                         .append(context.constantToString(initializer.value)).append(";").softNewLine();
+                int sz = writer.getOffset() - start;
+                appendClassSize(initializer.field.getClassName(), sz);
             }
         } catch (IOException e) {
             throw new RenderingException("IO error", e);
         }
     }
 
+    private void appendClassSize(String className, int sz) {
+        sizeByClass.put(className, sizeByClass.getOrDefault(className, 0) + sz);
+    }
+
     public void renderRuntime() throws RenderingException {
         try {
             renderSetCloneMethod();
@@ -291,8 +322,10 @@ public class Renderer implements RenderingManager {
             }
         }
         for (ClassNode cls : classes) {
+            int start = writer.getOffset();
             renderDeclaration(cls);
             renderMethodBodies(cls);
+            appendClassSize(cls.getName(), writer.getOffset() - start);
         }
         renderClassMetadata(classes);
     }
@@ -452,6 +485,7 @@ public class Renderer implements RenderingManager {
     }
 
     private void renderClassMetadata(List<ClassNode> classes) {
+        int start = writer.getOffset();
         try {
             writer.append("$rt_metadata([");
             boolean first = true;
@@ -506,6 +540,8 @@ public class Renderer implements RenderingManager {
         } catch (IOException e) {
             throw new RenderingException("IO error occurred", e);
         }
+
+        metadataSize = writer.getOffset() - start;
     }
 
     private void collectMethodsToCopyFromInterfaces(ClassReader cls, List<MethodReference> targetList) {