Added support for getting dex file stats: checkum, signature, map.

dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexBackedDexFile.java

@@ -31,10 +31,12 @@
 
 package org.jf.dexlib2.dexbacked;
 
+import org.jf.dexlib2.dexbacked.util.FixedSizeList;
 import org.jf.dexlib2.dexbacked.util.FixedSizeSet;
 import org.jf.dexlib2.iface.DexFile;
 
 import javax.annotation.Nonnull;
+import java.util.List;
 import java.util.Set;
 
 public class DexBackedDexFile implements DexFile {
@@ -63,4 +65,30 @@ public class DexBackedDexFile implements DexFile {
             }
         };
     }
+
+    public int getChecksum() {
+        return dexBuf.getChecksum();
+    }
+
+    public byte[] getSignature() {
+        return dexBuf.getSignature();
+    }
+
+    public List<DexBackedMapItem> getMap() {
+        final int mapOffset = dexBuf.getMapOffset();
+        final int sectionCount = dexBuf.readSmallUint(mapOffset);
+
+        return new FixedSizeList<DexBackedMapItem>() {
+            @Override
+            public DexBackedMapItem readItem(int index) {
+                int mapItemOffset = mapOffset + index * DexBuffer.MAP_ITEM_SIZE;
+                return new DexBackedMapItem(dexBuf, mapItemOffset);
+            }
+
+            @Override
+            public int size() {
+                return sectionCount;
+            }
+        };
+    }
 }

dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexBackedMapItem.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2012, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package org.jf.dexlib2.dexbacked;
+
+import javax.annotation.Nonnull;
+
+public class DexBackedMapItem {
+    @Nonnull public final DexBuffer dexBuf;
+    private final int mapItemOffset;
+
+    private static final int TYPE_OFFSET = 0;
+    private static final int SIZE_OFFSET = 4;
+    private static final int OFFSET_OFFSET = 8;
+
+    DexBackedMapItem(@Nonnull DexBuffer dexBuf,
+                     int mapItemOffset) {
+        this.dexBuf = dexBuf;
+        this.mapItemOffset = mapItemOffset;
+    }
+
+    public int getType() {
+        return dexBuf.readUshort(mapItemOffset + TYPE_OFFSET);
+    }
+
+    public int getNumItems() {
+        return dexBuf.readSmallUint(mapItemOffset + SIZE_OFFSET);
+    }
+
+    public int getOffset() {
+        return dexBuf.readSmallUint(mapItemOffset + OFFSET_OFFSET);
+    }
+}

dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexBuffer.java

@@ -37,6 +37,7 @@ import org.jf.util.Utf8Utils;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
+import java.util.Arrays;
 
 public class DexBuffer {
     // TODO: consider using a direct ByteBuffer instead
@@ -61,7 +62,10 @@ public class DexBuffer {
     private static final int LITTLE_ENDIAN_TAG = 0x12345678;
     private static final int BIG_ENDIAN_TAG = 0x78563412;
 
+    private static final int CHECKSUM_OFFSET = 8;
+    private static final int SIGNATURE_OFFSET = 12;
     private static final int ENDIAN_TAG_OFFSET = 40;
+    private static final int MAP_OFFSET = 52;
     private static final int STRING_COUNT_OFFSET = 56;
     private static final int STRING_START_OFFSET = 60;
     private static final int TYPE_COUNT_OFFSET = 64;
@@ -75,12 +79,15 @@ public class DexBuffer {
     private static final int CLASS_COUNT_OFFSET = 96;
     private static final int CLASS_START_OFFSET = 100;
 
+    private static final int SIGNATURE_SIZE = 20;
+
     private static final int STRING_ID_ITEM_SIZE = 4;
     private static final int TYPE_ID_ITEM_SIZE = 4;
     private static final int PROTO_ID_ITEM_SIZE = 12;
     private static final int FIELD_ID_ITEM_SIZE = 8;
     private static final int METHOD_ID_ITEM_SIZE = 8;
     private static final int CLASS_DEF_ITEM_SIZE = 32;
+    public static final int MAP_ITEM_SIZE = 12;
 
     public static final int FIELD_CLASS_IDX_OFFSET = 0;
     public static final int FIELD_TYPE_IDX_OFFSET = 2;
@@ -164,6 +171,18 @@ public class DexBuffer {
         }
     }
 
+    public int getChecksum() {
+        return readInt(CHECKSUM_OFFSET);
+    }
+
+    public byte[] getSignature() {
+        return Arrays.copyOfRange(this.buf, SIGNATURE_OFFSET, SIGNATURE_OFFSET + SIGNATURE_SIZE);
+    }
+
+    public int getMapOffset() {
+        return readSmallUint(MAP_OFFSET);
+    }
+
     public int getStringIdItemOffset(int stringIndex) {
         if (stringIndex < 0 || stringIndex >= stringCount) {
             throw new ExceptionWithContext("String index out of bounds: %d", stringIndex);