Refactoring of DebugInformation. Reduce memory consumption and debug

file size. Add debug information reader

teavm-core/src/main/java/org/teavm/debugging/DebugInformation.java

@@ -17,11 +17,11 @@ package org.teavm.debugging;
 
 import java.io.DataOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.OutputStream;
-import java.util.Arrays;
+import java.util.*;
-import java.util.Collection;
+import org.teavm.common.IntegerArray;
-import java.util.Collections;
+import org.teavm.model.MethodDescriptor;
-import java.util.Map;
 import org.teavm.model.MethodReference;
 
 /**
@@ -31,12 +31,15 @@ import org.teavm.model.MethodReference;
 public class DebugInformation {
     String[] fileNames;
     Map<String, Integer> fileNameMap;
+    String[] classNames;
+    Map<String, Integer> classNameMap;
+    String[] methods;
+    Map<String, Integer> methodMap;
     FileDescription[] fileDescriptions;
-    // TODO: for less memory consumption replace with two arrays + custom binary search
+    Mapping fileMapping;
-    GeneratedLocation[] fileNameKeys;
+    Mapping classMapping;
-    int[] fileNameValues;
+    Mapping methodMapping;
-    GeneratedLocation[] lineNumberKeys;
+    Mapping lineMapping;
-    int[] lineNumberValues;
 
     public Collection<GeneratedLocation> getGeneratedLocations(String fileName, int line) {
         Integer fileIndex = fileNameMap.get(fileName);
@@ -45,11 +48,19 @@ public class DebugInformation {
         }
         FileDescription description = fileIndex >= 0 ? fileDescriptions[fileIndex] : null;
         if (description == null) {
-            return null;
+            return Collections.emptyList();
         }
-        GeneratedLocation[] locations = line < description.generatedLocations.length ?
+        if (line > description.generatedLocationStart.length) {
-                description.generatedLocations[line] : null;
+            return Collections.emptyList();
-        return locations != null ? Arrays.asList(locations) : Collections.<GeneratedLocation>emptyList();
+        }
+        int start = description.generatedLocationStart[line];
+        int end = description.generatedLocationStart[line + 1];
+        GeneratedLocation[] resultArray = new GeneratedLocation[(end - start) / 2];
+        for (int i = 0; i < resultArray.length; ++i) {
+            resultArray[i] = new GeneratedLocation(description.generatedLocationData[i * 2],
+                    description.generatedLocationData[i * 2 + 1]);
+        }
+        return Arrays.asList(resultArray);
     }
 
     public Collection<GeneratedLocation> getGeneratedLocations(SourceLocation sourceLocation) {
@@ -61,40 +72,32 @@ public class DebugInformation {
     }
 
     public SourceLocation getSourceLocation(GeneratedLocation generatedLocation) {
-        String fileName = componentByKey(fileNameKeys, fileNameValues, fileNames, generatedLocation);
+        String fileName = componentByKey(fileMapping, fileNames, generatedLocation);
-        int lineNumberIndex = indexByKey(lineNumberKeys, generatedLocation);
+        int lineNumberIndex = indexByKey(lineMapping, generatedLocation);
-        int lineNumber = lineNumberIndex >= 0 ? lineNumberValues[lineNumberIndex] : -1;
+        int lineNumber = lineNumberIndex >= 0 ? lineMapping.values[lineNumberIndex] : -1;
         return new SourceLocation(fileName, lineNumber);
     }
 
-    public MethodReference getMethodAt(String fileName, int line) {
+    public MethodReference getMethodAt(GeneratedLocation generatedLocation) {
-        if (line < 0) {
+        String className = componentByKey(classMapping, classNames, generatedLocation);
+        if (className == null) {
             return null;
         }
-        Integer fileIndex = fileNameMap.get(fileName);
+        String method = componentByKey(methodMapping, methods, generatedLocation);
-        if (fileIndex == null) {
+        if (method == null) {
             return null;
         }
-        FileDescription description = fileDescriptions[fileIndex];
+        return new MethodReference(className, MethodDescriptor.parse(method));
-        if (description == null) {
-            return null;
-        }
-        return line < description.methodMap.length ? description.methodMap[line] : null;
     }
 
-    public MethodReference getMethodAt(SourceLocation sourceLocation) {
+    private <T> T componentByKey(Mapping mapping, T[] values, GeneratedLocation location) {
-        return getMethodAt(sourceLocation.getFileName(), sourceLocation.getLine());
+        int keyIndex = indexByKey(mapping, location);
-    }
+        int valueIndex = keyIndex >= 0 ? mapping.values[keyIndex] : -1;
-
-    private <T> T componentByKey(GeneratedLocation[] keys, int[] valueIndexes, T[] values,
-            GeneratedLocation location) {
-        int keyIndex = indexByKey(keys, location);
-        int valueIndex = keyIndex >= 0 ? valueIndexes[keyIndex] : -1;
         return valueIndex >= 0 ? values[valueIndex] : null;
     }
 
-    private int indexByKey(GeneratedLocation[] keys, GeneratedLocation location) {
+    private int indexByKey(Mapping mapping, GeneratedLocation location) {
-        int index = Arrays.binarySearch(keys, location);
+        int index = Collections.binarySearch(mapping.keyList(), location);
         return index >= 0 ? index : -index - 2;
     }
 
@@ -103,8 +106,179 @@ public class DebugInformation {
         writer.write(this);
     }
 
+    public DebugInformation read(InputStream input) throws IOException {
+        DebugInformationReader reader = new DebugInformationReader(input);
+        return reader.read();
+    }
+
+    void rebuildMaps() {
+        fileNameMap = mapArray(fileNames);
+        classNameMap = mapArray(classNames);
+        methodMap = mapArray(methods);
+    }
+
+    private Map<String, Integer> mapArray(String[] array) {
+        Map<String, Integer> map = new HashMap<>();
+        for (int i = 0; i < array.length; ++i) {
+            map.put(array[i], i);
+        }
+        return map;
+    }
+
+    void rebuildFileDescriptions() {
+        FileDescriptionBuilder builder = new FileDescriptionBuilder(fileNames.length);
+        int fileIndex = 0;
+        int lineIndex = 0;
+        int currentFile = -1;
+        int currentLine = -1;
+        while (fileIndex < fileMapping.size() && lineIndex < lineMapping.size()) {
+            GeneratedLocation fileLoc = fileMapping.key(fileIndex);
+            GeneratedLocation lineLoc = lineMapping.key(lineIndex);
+            int cmp = fileLoc.compareTo(lineLoc);
+            if (cmp < 0) {
+                currentFile = fileMapping.values[fileIndex++];
+            } else if (cmp > 0){
+                currentLine = lineMapping.values[lineIndex++];
+            } else {
+                currentFile = fileMapping.values[fileIndex++];
+                currentLine = lineMapping.values[lineIndex++];
+            }
+            builder.emit(fileLoc.getLine(), fileLoc.getColumn(), currentFile, currentLine);
+        }
+        while (fileIndex < fileMapping.size()) {
+            builder.emit(fileMapping.lines[fileIndex], fileMapping.columns[fileIndex],
+                    fileMapping.values[fileIndex], currentLine);
+            ++fileIndex;
+        }
+        while (lineIndex < lineMapping.size()) {
+            builder.emit(lineMapping.lines[lineIndex], lineMapping.columns[lineIndex], currentFile,
+                    lineMapping.values[lineIndex]);
+            ++lineIndex;
+        }
+        fileDescriptions = builder.build();
+    }
+
+    static class FileDescriptionBuilder {
+        FileDescriptionProto[] files;
+
+        public FileDescriptionBuilder(int size) {
+            files = new FileDescriptionProto[size];
+            for (int i = 0; i < size; ++i) {
+                files[i] = new FileDescriptionProto();
+            }
+        }
+
+        void emit(int line, int column, int fileIndex, int sourceLine) {
+            if (sourceLine == -1 || fileIndex == -1) {
+                return;
+            }
+            FileDescriptionProto proto = files[fileIndex];
+            proto.addLocation(sourceLine, line, column);
+        }
+
+        public FileDescription[] build() {
+            FileDescription[] descriptions = new FileDescription[files.length];
+            for (int i = 0; i < files.length; ++i) {
+                descriptions[i] = files[i].build();
+            }
+            return descriptions;
+        }
+    }
+
+    static class FileDescriptionProto {
+        IntegerArray generatedLocationData = new IntegerArray(1);
+        IntegerArray generatedLocationPointers = new IntegerArray(1);
+        IntegerArray generatedLocationStart = new IntegerArray(1);
+        IntegerArray generatedLocationSize = new IntegerArray(1);
+
+        public void addLocation(int sourceLine, int line, int column) {
+            ensureLine(sourceLine);
+            generatedLocationSize.set(sourceLine, generatedLocationSize.get(sourceLine) + 1);
+            int slot = generatedLocationStart.get(sourceLine);
+            slot = addData(slot, column);
+            slot = addData(slot, line);
+            generatedLocationStart.set(sourceLine, slot);
+        }
+
+        int addData(int slot, int value) {
+            int result = generatedLocationData.size();
+            generatedLocationData.add(value);
+            generatedLocationPointers.add(slot);
+            return result;
+        }
+
+        void ensureLine(int sourceLine) {
+            while (sourceLine >= generatedLocationSize.size()) {
+                generatedLocationSize.add(0);
+                generatedLocationStart.add(-1);
+            }
+        }
+
+        FileDescription build() {
+            FileDescription description = new FileDescription();
+            description.generatedLocationData = new int[generatedLocationData.size()];
+            description.generatedLocationStart = new int[generatedLocationStart.size()];
+            int current = 0;
+            for (int i = 0; i < generatedLocationStart.size(); ++i) {
+                description.generatedLocationStart[i] = current;
+                current += generatedLocationSize.get(i) * 2;
+                int j = current;
+                int ptr = generatedLocationStart.get(i);
+                while (ptr >= 0) {
+                    description.generatedLocationData[--j] = generatedLocationData.get(ptr);
+                    ptr = generatedLocationPointers.get(ptr);
+                }
+            }
+            return description;
+        }
+    }
+
     static class FileDescription {
-        GeneratedLocation[][] generatedLocations;
+        int[] generatedLocationData;
-        MethodReference[] methodMap;
+        int[] generatedLocationStart;
+    }
+
+    static class Mapping {
+        int[] lines;
+        int[] columns;
+        int[] values;
+
+        public Mapping(int[] lines, int[] columns, int[] values) {
+            this.lines = lines;
+            this.columns = columns;
+            this.values = values;
+        }
+
+        public LocationList keyList() {
+            return new LocationList(lines, columns);
+        }
+
+        public int size() {
+            return lines.length;
+        }
+
+        public GeneratedLocation key(int index) {
+            return new GeneratedLocation(lines[index], columns[index]);
+        }
+    }
+
+    static class LocationList extends AbstractList<GeneratedLocation> {
+        private int[] lines;
+        private int[] columns;
+
+        public LocationList(int[] lines, int[] columns) {
+            this.lines = lines;
+            this.columns = columns;
+        }
+
+        @Override
+        public GeneratedLocation get(int index) {
+            return new GeneratedLocation(lines[index], columns[index]);
+        }
+
+        @Override
+        public int size() {
+            return lines.length;
+        }
     }
 }

teavm-core/src/main/java/org/teavm/debugging/DebugInformationBuilder.java

@@ -17,7 +17,8 @@ package org.teavm.debugging;
 
 import java.util.*;
 import org.teavm.codegen.LocationProvider;
-import org.teavm.model.MethodReference;
+import org.teavm.common.IntegerArray;
+import org.teavm.model.MethodDescriptor;
 
 /**
  *
@@ -26,14 +27,17 @@ import org.teavm.model.MethodReference;
 public class DebugInformationBuilder implements DebugInformationEmitter {
     private LocationProvider locationProvider;
     private DebugInformation debugInformation;
-    private List<String> fileNames = new ArrayList<>();
+    private MappedList files = new MappedList();
-    private Map<String, Integer> fileNameMap = new HashMap<>();
+    private MappedList classes = new MappedList();
-    private List<Entry> fileNameEntries = new ArrayList<>();
+    private MappedList methods = new MappedList();
-    private List<Entry> lineNumberEntries = new ArrayList<>();
+    private Mapping fileMapping = new Mapping();
-    private MethodReference currentMethod;
+    private Mapping lineMapping = new Mapping();
+    private Mapping classMapping = new Mapping();
+    private Mapping methodMapping = new Mapping();
+    private MethodDescriptor currentMethod;
+    private String currentClass;
     private String currentFileName;
     private int currentLine;
-    private List<FileDescriptionProto> fileDescriptions = new ArrayList<>();
 
     public LocationProvider getLocationProvider() {
         return locationProvider;
@@ -44,118 +48,100 @@ public class DebugInformationBuilder implements DebugInformationEmitter {
         this.locationProvider = locationProvider;
     }
 
-    private GeneratedLocation getGeneratedLocation() {
-        return new GeneratedLocation(locationProvider.getLine(), locationProvider.getColumn());
-    }
-
     @Override
     public void emitLocation(String fileName, int line) {
         debugInformation = null;
-        Integer fileIndex;
+        int fileIndex = files.index(fileName);
-        if (fileName != null) {
+        if (!Objects.equals(currentFileName, fileName)) {
-            fileIndex = fileNameMap.get(fileName);
+            fileMapping.add(locationProvider, fileIndex);
-            if (fileIndex == null) {
+            currentFileName = fileName;
-                fileIndex = fileNames.size();
-                fileNames.add(fileName);
-                fileNameMap.put(fileName, fileIndex);
-                fileDescriptions.add(new FileDescriptionProto());
-            }
-        } else {
-            fileIndex = -1;
-        }
-        if (currentFileName != fileName) {
-            fileNameEntries.add(new Entry(getGeneratedLocation(), fileIndex));
         }
         if (currentLine != line) {
-            lineNumberEntries.add(new Entry(getGeneratedLocation(), line));
+            lineMapping.add(locationProvider, line);
-        }
+            currentLine = line;
-        if (fileName != null && line >= 0 && (currentFileName != fileName || currentLine != line)) {
-            FileDescriptionProto fileDesc = fileDescriptions.get(fileIndex);
-            fileDesc.setMethod(line, currentMethod);
-            fileDesc.addGeneratedLocation(line, getGeneratedLocation());
         }
     }
 
     @Override
-    public void emitMethod(MethodReference method) {
+    public void emitClass(String className) {
         debugInformation = null;
+        int classIndex = classes.index(className);
+        if (!Objects.equals(className, currentClass)) {
+            classMapping.add(locationProvider, classIndex);
+            currentClass = className;
+        }
+    }
+
+    @Override
+    public void emitMethod(MethodDescriptor method) {
+        debugInformation = null;
+        int methodIndex = methods.index(method != null ? method.toString() : null);
+        if (!Objects.equals(method, currentMethod)) {
+            methodMapping.add(locationProvider, methodIndex);
             currentMethod = method;
         }
+    }
 
     public DebugInformation getDebugInformation() {
         if (debugInformation == null) {
             debugInformation = new DebugInformation();
 
-            debugInformation.fileNames = fileNames.toArray(new String[0]);
+            debugInformation.fileNames = files.getItems();
-            debugInformation.fileNameMap = new HashMap<>(fileNameMap);
+            debugInformation.fileNameMap = files.getIndexes();
+            debugInformation.classNames = classes.getItems();
+            debugInformation.classNameMap = classes.getIndexes();
+            debugInformation.methods = methods.getItems();
+            debugInformation.methodMap = methods.getIndexes();
 
-            debugInformation.fileNameKeys = new GeneratedLocation[fileNameEntries.size()];
+            debugInformation.fileMapping = fileMapping.build();
-            debugInformation.fileNameValues = new int[fileNameEntries.size()];
+            debugInformation.lineMapping = lineMapping.build();
-            int index = 0;
+            debugInformation.classMapping = classMapping.build();
-            for (Entry entry : fileNameEntries) {
+            debugInformation.methodMapping = methodMapping.build();
-                debugInformation.fileNameKeys[index] = entry.key;
-                debugInformation.fileNameValues[index] = entry.value;
-                index++;
-            }
 
-            debugInformation.lineNumberKeys = new GeneratedLocation[lineNumberEntries.size()];
+            debugInformation.rebuildFileDescriptions();
-            debugInformation.lineNumberValues = new int[lineNumberEntries.size()];
-            index = 0;
-            for (Entry entry : lineNumberEntries) {
-                debugInformation.lineNumberKeys[index] = entry.key;
-                debugInformation.lineNumberValues[index] = entry.value;
-                index++;
-            }
-
-            debugInformation.fileDescriptions = new DebugInformation.FileDescription[fileDescriptions.size()];
-            index = 0;
-            for (FileDescriptionProto fileDescProto : fileDescriptions) {
-                DebugInformation.FileDescription fileDesc = new DebugInformation.FileDescription();
-                debugInformation.fileDescriptions[index++] = fileDesc;
-                fileDesc.methodMap = fileDescProto.methodMap.toArray(new MethodReference[0]);
-                fileDesc.generatedLocations = new GeneratedLocation[fileDescProto.generatedLocations.size()][];
-                for (int i = 0; i < fileDescProto.generatedLocations.size(); ++i) {
-                    List<GeneratedLocation> locations = fileDescProto.generatedLocations.get(index);
-                    fileDesc.generatedLocations[i] = locations != null ?
-                            locations.toArray(new GeneratedLocation[0]) : null;
-                }
-            }
         }
         return debugInformation;
     }
 
-    static class FileDescriptionProto {
+    static class Mapping {
-        List<List<GeneratedLocation>> generatedLocations = new ArrayList<>();
+        IntegerArray lines = new IntegerArray(1);
-        List<MethodReference> methodMap = new ArrayList<>();
+        IntegerArray columns = new IntegerArray(1);
+        IntegerArray values = new IntegerArray(1);
 
-        void addGeneratedLocation(int line, GeneratedLocation location) {
+        public void add(LocationProvider location, int value) {
-            if (line >= generatedLocations.size()) {
+            lines.add(location.getLine());
-                generatedLocations.addAll(Collections.<List<GeneratedLocation>>nCopies(
+            columns.add(location.getColumn());
-                        line - generatedLocations.size() + 1, null));
+            values.add(value);
-            }
-            List<GeneratedLocation> existingLocations = generatedLocations.get(line);
-            if (existingLocations == null) {
-                existingLocations = new ArrayList<>();
-                generatedLocations.set(line, existingLocations);
-            }
-            existingLocations.add(location);
         }
 
-        void setMethod(int line, MethodReference method) {
+        DebugInformation.Mapping build() {
-            if (line >= methodMap.size()) {
+            return new DebugInformation.Mapping(lines.getAll(), columns.getAll(), values.getAll());
-                methodMap.addAll(Collections.<MethodReference>nCopies(line - methodMap.size() + 1, null));
-            }
-            methodMap.set(line, method);
         }
     }
 
-    static class Entry {
+    static class MappedList {
-        GeneratedLocation key;
+        private List<String> list = new ArrayList<>();
-        int value;
+        private Map<String, Integer> map = new HashMap<>();
 
-        public Entry(GeneratedLocation key, int value) {
+        public int index(String item) {
-            this.key = key;
+            if (item == null) {
-            this.value = value;
+                return -1;
+            }
+            Integer index = map.get(item);
+            if (index == null) {
+                index = list.size();
+                list.add(item);
+                map.put(item, index);
+            }
+            return index;
+        }
+
+        public String[] getItems() {
+            return list.toArray(new String[list.size()]);
+        }
+
+        public Map<String, Integer> getIndexes() {
+            return new HashMap<>(map);
         }
     }
 }

teavm-core/src/main/java/org/teavm/debugging/DebugInformationEmitter.java

@@ -16,7 +16,7 @@
 package org.teavm.debugging;
 
 import org.teavm.codegen.LocationProvider;
-import org.teavm.model.MethodReference;
+import org.teavm.model.MethodDescriptor;
 
 /**
  *
@@ -27,5 +27,7 @@ public interface DebugInformationEmitter {
 
     void emitLocation(String fileName, int line);
 
-    void emitMethod(MethodReference method);
+    void emitMethod(MethodDescriptor method);
+
+    void emitClass(String className);
 }

teavm-core/src/main/java/org/teavm/debugging/DebugInformationReader.java

@@ -0,0 +1,138 @@
+/*
+ *  Copyright 2014 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.debugging;
+
+import java.io.EOFException;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ *
+ * @author Alexey Andreev
+ */
+class DebugInformationReader {
+    private InputStream input;
+    private int lastNumber;
+
+    public DebugInformationReader(InputStream input) {
+        this.input = input;
+    }
+
+    public DebugInformation read() throws IOException {
+        DebugInformation debugInfo = new DebugInformation();
+        debugInfo.fileNames = readStrings();
+        debugInfo.classNames = readStrings();
+        debugInfo.methods = readStrings();
+        debugInfo.fileMapping = readMapping();
+        debugInfo.lineMapping = readMapping();
+        debugInfo.classMapping = readMapping();
+        debugInfo.methodMapping = readMapping();
+        debugInfo.rebuildFileDescriptions();
+        return debugInfo;
+    }
+
+    private int processSign(int number) {
+        boolean negative = (number & 1) == 1;
+        number >>>= 1;
+        return !negative ? number : -number;
+    }
+
+    private DebugInformation.Mapping readMapping() throws IOException {
+        int[] lines = readRle();
+        int last = 0;
+        for (int i = 0; i < lines.length; ++i) {
+            last += lines[i];
+            lines[i] = last;
+        }
+        int[] columns = new int[readUnsignedNumber()];
+        resetRelativeNumber();
+        for (int i = 0; i < columns.length; ++i) {
+            columns[i] = readRelativeNumber();
+        }
+        int[] values = new int[readUnsignedNumber()];
+        resetRelativeNumber();
+        for (int i = 0; i < values.length; ++i) {
+            values[i] = readRelativeNumber();
+        }
+        return new DebugInformation.Mapping(lines, columns, values);
+    }
+
+    private String[] readStrings() throws IOException {
+        String[] array = new String[readUnsignedNumber()];
+        for (int i = 0; i < array.length; ++i) {
+            array[i] = readString();
+        }
+        return array;
+    }
+
+    private int[] readRle() throws IOException {
+        int[] array = new int[readUnsignedNumber()];
+        for (int i = 0; i < array.length;) {
+            int n = readUnsignedNumber();
+            int count = 1;
+            if ((n & 1) != 0) {
+                count = readUnsignedNumber();
+            }
+            n = processSign(n >>> 1);
+            while (count-- > 0) {
+                array[i] = n;
+            }
+        }
+        return array;
+    }
+
+    private int readNumber() throws IOException {
+        return processSign(readUnsignedNumber());
+    }
+
+    private int readUnsignedNumber() throws IOException {
+        int number = 0;
+        while (true) {
+            int r = input.read();
+            if (r < 0) {
+                throw new EOFException();
+            }
+            byte b = (byte)r;
+            number = (number << 7) | (b & 0x7F);
+            if ((b & 0x80) == 0) {
+                break;
+            }
+        }
+        return number;
+    }
+
+    private int readRelativeNumber() throws IOException {
+        lastNumber += readNumber();
+        return lastNumber;
+    }
+
+    private void resetRelativeNumber() {
+        lastNumber = 0;
+    }
+
+    private String readString() throws IOException {
+        byte[] bytes = new byte[readUnsignedNumber()];
+        int pos = 0;
+        while (pos < bytes.length) {
+            int read = input.read(bytes, pos, bytes.length - pos);
+            if (read == -1) {
+                throw new EOFException();
+            }
+            pos += read;
+        }
+        return new String(bytes, "UTF-8");
+    }
+}

teavm-core/src/main/java/org/teavm/debugging/DebugInformationWriter.java

@@ -17,12 +17,6 @@ package org.teavm.debugging;
 
 import java.io.DataOutput;
 import java.io.IOException;
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.Map;
-import org.teavm.common.IntegerArray;
-import org.teavm.debugging.DebugInformation.FileDescription;
-import org.teavm.model.MethodReference;
 
 /**
  *
@@ -37,84 +31,52 @@ class DebugInformationWriter {
     }
 
     public void write(DebugInformation debugInfo) throws IOException {
-        writeNumber(debugInfo.fileNames.length);
+        writeStringArray(debugInfo.fileNames);
-        for (int i = 0; i < debugInfo.fileNames.length; ++i) {
+        writeStringArray(debugInfo.classNames);
-            String fileName = debugInfo.fileNames[i];
+        writeStringArray(debugInfo.methods);
-            writeString(fileName);
+
-            writeMethods(debugInfo.fileDescriptions[i]);
+        writeMapping(debugInfo.fileMapping);
+        writeMapping(debugInfo.lineMapping);
+        writeMapping(debugInfo.classMapping);
+        writeMapping(debugInfo.methodMapping);
     }
 
-        writeNumber(debugInfo.fileNameKeys.length);
+    private void writeStringArray(String[] array) throws IOException {
-        resetRelativeNumber();
+        writeUnsignedNumber(array.length);
-        for (int i = 0; i < debugInfo.fileNameKeys.length; ++i) {
+        for (int i = 0; i < array.length; ++i) {
-            writeRelativeNumber(debugInfo.fileNameKeys[i].getLine());
+            writeString(array[i]);
-        }
-        resetRelativeNumber();
-        for (int i = 0; i < debugInfo.fileNameKeys.length; ++i) {
-            writeRelativeNumber(debugInfo.fileNameKeys[i].getColumn());
-        }
-        resetRelativeNumber();
-        for (int i = 0; i < debugInfo.fileNameValues.length; ++i) {
-            writeRelativeNumber(debugInfo.fileNameValues[i]);
-        }
-
-        writeNumber(debugInfo.lineNumberKeys.length);
-        resetRelativeNumber();
-        resetRelativeNumber();
-        for (int i = 0; i < debugInfo.lineNumberKeys.length; ++i) {
-            writeRelativeNumber(debugInfo.lineNumberKeys[i].getLine());
-        }
-        resetRelativeNumber();
-        for (int i = 0; i < debugInfo.lineNumberKeys.length; ++i) {
-            writeRelativeNumber(debugInfo.lineNumberKeys[i].getColumn());
-        }
-        resetRelativeNumber();
-        for (int i = 0; i < debugInfo.fileNameValues.length; ++i) {
-            writeRelativeNumber(debugInfo.lineNumberValues[i]);
         }
     }
 
-    private void writeMethods(FileDescription fileDesc) throws IOException {
+    private void writeMapping(DebugInformation.Mapping mapping) throws IOException {
-        Map<MethodReference, IntegerArray> methodLineMap = new HashMap<>();
+        writeUnsignedNumber(mapping.lines.length);
-        for (int i = 0; i < fileDesc.methodMap.length; ++i) {
+        int[] lines = mapping.lines.clone();
-            MethodReference method = fileDesc.methodMap[i];
+        int last = 0;
-            if (method == null) {
+        for (int i = 0; i < lines.length; ++i) {
-                continue;
+            last = lines[i];
+            lines[i] -= last;
         }
-            IntegerArray lines = methodLineMap.get(method);
+        writeRle(lines);
-            if (lines == null) {
+        resetRelativeNumber();
-                lines = new IntegerArray(1);
+        for (int i = 0; i < mapping.columns.length; ++i) {
-                methodLineMap.put(method, lines);
+            writeRelativeNumber(mapping.columns[i]);
         }
-            lines.add(i);
+        resetRelativeNumber();
-        }
+        for (int i = 0; i < mapping.values.length; ++i) {
-        writeNumber(methodLineMap.size());
+            writeRelativeNumber(mapping.values[i]);
-        for (MethodReference method : methodLineMap.keySet()) {
-            writeString(method.toString());
-            int[] lines = methodLineMap.get(method).getAll();
-            Arrays.sort(lines);
-            for (int i = 0; i < lines.length;) {
-                writeRelativeNumber(i);
-                int j = i;
-                int last = lines[i];
-                ++i;
-                while (i < lines.length && lines[i] == last + 1) {
-                    ++i;
-                    ++last;
-                }
-                writeNumber(i - j);
-            }
-            writeRelativeNumber(-1);
         }
     }
 
     private void writeNumber(int number) throws IOException {
-        do {
+        writeUnsignedNumber(convertToSigned(number));
-            if (number < 0) {
-                number = (-number << 1) | 1;
-            } else {
-                number = number << 1;
     }
+
+    private int convertToSigned(int number) {
+        return number < 0 ? (-number << 1) | 1 : number << 1;
+    }
+
+    private void writeUnsignedNumber(int number) throws IOException {
+        do {
             byte b = (byte)(number & 0x7F);
             if ((number & 0xFFFFFF80) != 0) {
                 b |= 0x80;
@@ -124,6 +86,25 @@ class DebugInformationWriter {
         } while (number != 0);
     }
 
+    private void writeRle(int[] array) throws IOException {
+        writeUnsignedNumber(array.length);
+        for (int i = 0; i < array.length;) {
+            int e = array[i];
+            int count = 1;
+            ++i;
+            while (i < array.length && array[i] == e) {
+                ++count;
+                ++i;
+            }
+            if (count > 1) {
+                writeUnsignedNumber((convertToSigned(e) << 1) | 1);
+                writeUnsignedNumber(count);
+            } else {
+                writeUnsignedNumber(convertToSigned(e) << 1);
+            }
+        }
+    }
+
     private void writeRelativeNumber(int number) throws IOException {
         writeNumber(number - lastNumber);
         lastNumber = number;
@@ -134,7 +115,8 @@ class DebugInformationWriter {
     }
 
     private void writeString(String str) throws IOException {
-        writeNumber(str.length());
+        byte[] bytes = str.getBytes("UTF-8");
-        output.write(str.getBytes("UTF-8"));
+        writeUnsignedNumber(bytes.length);
+        output.write(bytes);
     }
 }

teavm-core/src/main/java/org/teavm/debugging/Debugger.java

@@ -119,7 +119,7 @@ public class Debugger {
             for (JavaScriptCallFrame jsFrame : javaScriptDebugger.getCallStack()) {
                 SourceLocation loc = debugInformation.getSourceLocation(jsFrame.getLocation());
                 boolean empty = loc == null || (loc.getFileName() == null && loc.getLine() < 0);
-                MethodReference method = !empty ? debugInformation.getMethodAt(loc) : null;
+                MethodReference method = !empty ? debugInformation.getMethodAt(jsFrame.getLocation()) : null;
                 if (!empty || !wasEmpty) {
                     frames.add(new CallFrame(loc, method));
                 }

teavm-core/src/main/java/org/teavm/debugging/DummyDebugInformationEmitter.java

@@ -16,7 +16,7 @@
 package org.teavm.debugging;
 
 import org.teavm.codegen.LocationProvider;
-import org.teavm.model.MethodReference;
+import org.teavm.model.MethodDescriptor;
 
 
 /**
@@ -29,7 +29,11 @@ public class DummyDebugInformationEmitter implements DebugInformationEmitter {
     }
 
     @Override
-    public void emitMethod(MethodReference method) {
+    public void emitMethod(MethodDescriptor method) {
+    }
+
+    @Override
+    public void emitClass(String className) {
     }
 
     @Override

teavm-core/src/main/java/org/teavm/debugging/GeneratedLocation.java

@@ -44,4 +44,30 @@ public class GeneratedLocation implements Comparable<GeneratedLocation> {
         }
         return r;
     }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + column;
+        result = prime * result + line;
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null) {
+            return false;
+        }
+        GeneratedLocation other = (GeneratedLocation)obj;
+        return line == other.line && column == other.column;
+    }
+
+    @Override
+    public String toString() {
+        return "line: " + line + ", column: " + column;
+    }
 }

teavm-core/src/main/java/org/teavm/javascript/Renderer.java

@@ -242,6 +242,7 @@ public class Renderer implements ExprVisitor, StatementVisitor, RenderingContext
     }
 
     public void render(ClassNode cls) throws RenderingException {
+        debugEmitter.emitClass(cls.getName());
         try {
             writer.append("function ").appendClass(cls.getName()).append("()").ws().append("{")
                     .indent().softNewLine();
@@ -354,6 +355,7 @@ public class Renderer implements ExprVisitor, StatementVisitor, RenderingContext
         } catch (IOException e) {
             throw new RenderingException("IO error occured", e);
         }
+        debugEmitter.emitClass(null);
     }
 
     private static Object getDefaultValue(ValueType type) {
@@ -383,6 +385,7 @@ public class Renderer implements ExprVisitor, StatementVisitor, RenderingContext
 
     private void renderInitializer(MethodNode method) throws IOException {
         MethodReference ref = method.getReference();
+        debugEmitter.emitMethod(ref.getDescriptor());
         writer.appendClass(ref.getClassName()).append(".").appendMethod(ref).ws().append("=").ws().append("function(");
         for (int i = 1; i <= ref.parameterCount(); ++i) {
             if (i > 1) {
@@ -403,21 +406,23 @@ public class Renderer implements ExprVisitor, StatementVisitor, RenderingContext
         writer.append(");").softNewLine();
         writer.append("return result;").softNewLine();
         writer.outdent().append("}").newLine();
+        debugEmitter.emitMethod(null);
     }
 
     private void renderVirtualDeclarations(String className, List<MethodNode> methods)
             throws NamingException, IOException {
+        if (methods.isEmpty()) {
+            return;
+        }
         for (MethodNode method : methods) {
             MethodReference ref = method.getReference();
             if (ref.getDescriptor().getName().equals("<init>")) {
                 renderInitializer(method);
             }
         }
-        if (methods.isEmpty()) {
-            return;
-        }
         writer.append("$rt_virtualMethods(").appendClass(className).indent();
         for (MethodNode method : methods) {
+            debugEmitter.emitMethod(method.getReference().getDescriptor());
             MethodReference ref = method.getReference();
             writer.append(",").newLine();
             if (method.isOriginalNamePreserved()) {
@@ -443,12 +448,14 @@ public class Renderer implements ExprVisitor, StatementVisitor, RenderingContext
                 writer.append(",").ws().append(variableName(i));
             }
             writer.append(");").ws().append("}");
+            debugEmitter.emitMethod(null);
         }
         writer.append(");").newLine().outdent();
     }
 
     private void renderStaticDeclaration(MethodNode method) throws NamingException, IOException {
         MethodReference ref = method.getReference();
+        debugEmitter.emitMethod(ref.getDescriptor());
         if (ref.getDescriptor().getName().equals("<init>")) {
             renderInitializer(method);
         }
@@ -470,11 +477,12 @@ public class Renderer implements ExprVisitor, StatementVisitor, RenderingContext
             writer.appendClass(ref.getClassName()).append(".").append(ref.getName()).ws().append("=")
                     .ws().appendClass(ref.getClassName()).append(".").appendMethod(ref).append(';').newLine();
         }
+        debugEmitter.emitMethod(null);
     }
 
     public void renderBody(MethodNode method, boolean inner) throws IOException {
         MethodReference ref = method.getReference();
-        debugEmitter.emitMethod(ref);
+        debugEmitter.emitMethod(ref.getDescriptor());
         if (inner) {
             writer.appendMethodBody(ref).ws().append("=").ws().append("function(");
         } else {