preliminary support for reading in odex files

git-svn-id: https://smali.googlecode.com/svn/trunk@431 55b6fa8a-2a1e-11de-a435-ffa8d773f76a

dexlib/src/main/java/org/jf/dexlib/DexFile.java

@@ -34,6 +34,7 @@ import org.jf.dexlib.Item;
 import org.jf.dexlib.StringDataItem;
 
 import java.io.File;
+import java.io.UnsupportedEncodingException;
 import java.security.DigestException;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
@@ -266,7 +267,40 @@ public class DexFile
     public DexFile(File file, boolean preserveSignedRegisters) {
         this(preserveSignedRegisters);
 
-        Input in = new ByteArrayInput(FileUtils.readFile(file));
+        byte[] magic = FileUtils.readFile(file, 0, 8);
+        byte[] dexMagic, odexMagic;
+
+        try {
+            dexMagic = HeaderItem.MAGIC.getBytes("US-ASCII");
+            odexMagic = OdexHeaderItem.MAGIC.getBytes("US-ASCII");
+        } catch (UnsupportedEncodingException ex) {
+            throw new RuntimeException(ex);
+        }
+
+        boolean isDex = true;
+        boolean isOdex = true;
+        for (int i=0; i<8; i++) {
+            if (magic[i] != dexMagic[i]) {
+                isDex = false;
+            }
+            if (magic[i] != odexMagic[i]) {
+                isOdex = false;
+            }
+        }
+
+        Input in;
+
+        if (isOdex) {
+            byte[] odexHeaderBytes = FileUtils.readFile(file, 0, 40);
+            Input odexHeaderIn = new ByteArrayInput(odexHeaderBytes);
+            OdexHeaderItem odexHeader = new OdexHeaderItem(odexHeaderIn);
+
+            in = new ByteArrayInput(FileUtils.readFile(file, odexHeader.dexOffset, odexHeader.dexLength));
+        } else if (isDex) {
+            in = new ByteArrayInput(FileUtils.readFile(file));
+        } else {
+            throw new RuntimeException("bad magic value");
+        }
 
         ReadContext readContext = new ReadContext(this);
 

dexlib/src/main/java/org/jf/dexlib/HeaderItem.java

@@ -36,10 +36,10 @@ import java.io.UnsupportedEncodingException;
 
 public class HeaderItem extends Item<HeaderItem> {
     /**
-     * non-null; the file format magic number, represented as the
+     * the file format magic number, represented as the
      * low-order bytes of a string
      */
-    private static final String MAGIC = "dex\n035" + '\0';
+    public static final String MAGIC = "dex\n035" + '\0';
 
     /** size of this section, in bytes */
     private static final int HEADER_SIZE = 0x70;

dexlib/src/main/java/org/jf/dexlib/OdexHeaderItem.java

@@ -0,0 +1,78 @@
+/*
+ * [The "BSD licence"]
+ * Copyright (c) 2009 Ben Gruver
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.dexlib;
+
+import org.jf.dexlib.Util.Input;
+
+import java.io.UnsupportedEncodingException;
+
+public class OdexHeaderItem {
+
+    /**
+     * the file format magic number, represented as the
+     * low-order bytes of a string
+     */
+    public static final String MAGIC = "dey\n035" + '\0';
+
+    public final byte[] magic;
+    public final int dexOffset;
+    public final int dexLength;
+    public final int depsOffset;
+    public final int depsLength;
+    public final int auxOffset;
+    public final int auxLength;
+    public final int flags;
+
+    public OdexHeaderItem(Input in) {
+        magic = in.readBytes(8);
+
+        byte[] expectedMagic;
+        try {
+            expectedMagic = MAGIC.getBytes("US-ASCII");
+        } catch (UnsupportedEncodingException ex) {
+            throw new RuntimeException(ex);
+        }
+
+        for (int i=0; i<8; i++) {
+            if (expectedMagic[i] != magic[i]) {
+                throw new RuntimeException("The magic value is not the expected value");
+            }
+        }
+
+        dexOffset = in.readInt();
+        dexLength = in.readInt();
+        depsOffset = in.readInt();
+        depsLength = in.readInt();
+        auxOffset = in.readInt();
+        auxLength = in.readInt();
+        flags = in.readInt();
+        in.readInt(); //padding
+    }
+
+}

dexlib/src/main/java/org/jf/dexlib/Util/FileUtils.java

@@ -51,6 +51,20 @@ public final class FileUtils {
      * @return non-null; contents of the file
      */
     public static byte[] readFile(File file) {
+        return readFile(file, 0, -1);
+    }
+
+    /**
+     * Reads the specified block from the given file, translating
+     * {@link IOException} to a {@link RuntimeException} of some sort.
+     *
+     * @param file non-null; the file to read
+     * @param offset the offset to begin reading
+     * @param length the number of bytes to read, or -1 to read to the
+     * end of the file
+     * @return non-null; contents of the file
+     */
+    public static byte[] readFile(File file, int offset, int length) {
         if (!file.exists()) {
             throw new RuntimeException(file + ": file not found");
         }
@@ -64,16 +78,33 @@ public final class FileUtils {
         }
 
         long longLength = file.length();
-        int length = (int) longLength;
-        if (length != longLength) {
+        int fileLength = (int) longLength;
+        if (fileLength != longLength) {
             throw new RuntimeException(file + ": file too long");
         }
 
+        if (length == -1) {
+            length = fileLength - offset;
+        }
+
+        if (offset + length > fileLength) {
+            throw new RuntimeException(file + ": file too short");
+        }
+
         byte[] result = new byte[length];
 
         try {
             FileInputStream in = new FileInputStream(file);
-            int at = 0;
+
+            int at = offset;
+            while(at > 0) {
+                long amt = in.skip(at);
+                if (amt == -1) {
+                    throw new RuntimeException(file + ": unexpected EOF");
+                }
+                at -= amt;
+            }
+
             while (length > 0) {
                 int amt = in.read(result, at, length);
                 if (amt == -1) {