dex/src/main/java/com/android/dex/EncodedValueReader.java - platform/libcore - Git at Google

 /*
  * Copyright (C) 2011 The Android Open Source Project
  *
  * 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 com.android.dex;

 import com.android.dex.util.ByteInput;

 /**
  * Pull parser for encoded values.
  */
 public final class EncodedValueReader {
     public static final int ENCODED_BYTE = 0x00;
     public static final int ENCODED_SHORT = 0x02;
     public static final int ENCODED_CHAR = 0x03;
     public static final int ENCODED_INT = 0x04;
     public static final int ENCODED_LONG = 0x06;
     public static final int ENCODED_FLOAT = 0x10;
     public static final int ENCODED_DOUBLE = 0x11;
     public static final int ENCODED_STRING = 0x17;
     public static final int ENCODED_TYPE = 0x18;
     public static final int ENCODED_FIELD = 0x19;
     public static final int ENCODED_ENUM = 0x1b;
     public static final int ENCODED_METHOD = 0x1a;
     public static final int ENCODED_ARRAY = 0x1c;
     public static final int ENCODED_ANNOTATION = 0x1d;
     public static final int ENCODED_NULL = 0x1e;
     public static final int ENCODED_BOOLEAN = 0x1f;

     /** placeholder type if the type is not yet known */
     private static final int MUST_READ = -1;

     protected final ByteInput in;
     private int type = MUST_READ;
     private int annotationType;
     private int arg;

     public EncodedValueReader(ByteInput in) {
         this.in = in;
     }

     public EncodedValueReader(EncodedValue in) {
         this(in.asByteInput());
     }

     /**
      * Creates a new encoded value reader whose only value is the specified
      * known type. This is useful for encoded values without a type prefix,
      * such as class_def_item's encoded_array or annotation_item's
      * encoded_annotation.
      */
     public EncodedValueReader(ByteInput in, int knownType) {
         this.in = in;
         this.type = knownType;
     }

     public EncodedValueReader(EncodedValue in, int knownType) {
         this(in.asByteInput(), knownType);
     }

     /**
      * Returns the type of the next value to read.
      */
     public int peek() {
         if (type == MUST_READ) {
             int argAndType = in.readByte() & 0xff;
             type = argAndType & 0x1f;
             arg = (argAndType & 0xe0) >> 5;
         }
         return type;
     }

     /**
      * Begins reading the elements of an array, returning the array's size. The
      * caller must follow up by calling a read method for each element in the
      * array. For example, this reads a byte array: <pre>   {@code
      *   int arraySize = readArray();
      *   for (int i = 0, i < arraySize; i++) {
      *     readByte();
      *   }
      * }</pre>
      */
     public int readArray() {
         checkType(ENCODED_ARRAY);
         type = MUST_READ;
         return Leb128.readUnsignedLeb128(in);
     }

     /**
      * Begins reading the fields of an annotation, returning the number of
      * fields. The caller must follow up by making alternating calls to {@link
      * #readAnnotationName()} and another read method. For example, this reads
      * an annotation whose fields are all bytes: <pre>   {@code
      *   int fieldCount = readAnnotation();
      *   int annotationType = getAnnotationType();
      *   for (int i = 0; i < fieldCount; i++) {
      *       readAnnotationName();
      *       readByte();
      *   }
      * }</pre>
      */
     public int readAnnotation() {
         checkType(ENCODED_ANNOTATION);
         type = MUST_READ;
         annotationType = Leb128.readUnsignedLeb128(in);
         return Leb128.readUnsignedLeb128(in);
     }

     /**
      * Returns the type of the annotation just returned by {@link
      * #readAnnotation()}. This method's value is undefined unless the most
      * recent call was to {@link #readAnnotation()}.
      */
     public int getAnnotationType() {
         return annotationType;
     }

     public int readAnnotationName() {
         return Leb128.readUnsignedLeb128(in);
     }

     public byte readByte() {
         checkType(ENCODED_BYTE);
         type = MUST_READ;
         return (byte) EncodedValueCodec.readSignedInt(in, arg);
     }

     public short readShort() {
         checkType(ENCODED_SHORT);
         type = MUST_READ;
         return (short) EncodedValueCodec.readSignedInt(in, arg);
     }

     public char readChar() {
         checkType(ENCODED_CHAR);
         type = MUST_READ;
         return (char) EncodedValueCodec.readUnsignedInt(in, arg, false);
     }

     public int readInt() {
         checkType(ENCODED_INT);
         type = MUST_READ;
         return EncodedValueCodec.readSignedInt(in, arg);
     }

     public long readLong() {
         checkType(ENCODED_LONG);
         type = MUST_READ;
         return EncodedValueCodec.readSignedLong(in, arg);
     }

     public float readFloat() {
         checkType(ENCODED_FLOAT);
         type = MUST_READ;
         return Float.intBitsToFloat(EncodedValueCodec.readUnsignedInt(in, arg, true));
     }

     public double readDouble() {
         checkType(ENCODED_DOUBLE);
         type = MUST_READ;
         return Double.longBitsToDouble(EncodedValueCodec.readUnsignedLong(in, arg, true));
     }

     public int readString() {
         checkType(ENCODED_STRING);
         type = MUST_READ;
         return EncodedValueCodec.readUnsignedInt(in, arg, false);
     }

     public int readType() {
         checkType(ENCODED_TYPE);
         type = MUST_READ;
         return EncodedValueCodec.readUnsignedInt(in, arg, false);
     }

     public int readField() {
         checkType(ENCODED_FIELD);
         type = MUST_READ;
         return EncodedValueCodec.readUnsignedInt(in, arg, false);
     }

     public int readEnum() {
         checkType(ENCODED_ENUM);
         type = MUST_READ;
         return EncodedValueCodec.readUnsignedInt(in, arg, false);
     }

     public int readMethod() {
         checkType(ENCODED_METHOD);
         type = MUST_READ;
         return EncodedValueCodec.readUnsignedInt(in, arg, false);
     }

     public void readNull() {
         checkType(ENCODED_NULL);
         type = MUST_READ;
     }

     public boolean readBoolean() {
         checkType(ENCODED_BOOLEAN);
         type = MUST_READ;
         return arg != 0;
     }

     /**
      * Skips a single value, including its nested values if it is an array or
      * annotation.
      */
     public void skipValue() {
         switch (peek()) {
         case ENCODED_BYTE:
             readByte();
             break;
         case ENCODED_SHORT:
             readShort();
             break;
         case ENCODED_CHAR:
             readChar();
             break;
         case ENCODED_INT:
             readInt();
             break;
         case ENCODED_LONG:
             readLong();
             break;
         case ENCODED_FLOAT:
             readFloat();
             break;
         case ENCODED_DOUBLE:
             readDouble();
             break;
         case ENCODED_STRING:
             readString();
             break;
         case ENCODED_TYPE:
             readType();
             break;
         case ENCODED_FIELD:
             readField();
             break;
         case ENCODED_ENUM:
             readEnum();
             break;
         case ENCODED_METHOD:
             readMethod();
             break;
         case ENCODED_ARRAY:
             for (int i = 0, size = readArray(); i < size; i++) {
                 skipValue();
             }
             break;
         case ENCODED_ANNOTATION:
             for (int i = 0, size = readAnnotation(); i < size; i++) {
                 readAnnotationName();
                 skipValue();
             }
             break;
         case ENCODED_NULL:
             readNull();
             break;
         case ENCODED_BOOLEAN:
             readBoolean();
             break;
         default:
             throw new DexException("Unexpected type: " + Integer.toHexString(type));
         }
     }

     private void checkType(int expected) {
         if (peek() != expected) {
             throw new IllegalStateException(
                     String.format("Expected %x but was %x", expected, peek()));
         }
     }
 }
	/*
	* Copyright (C) 2011 The Android Open Source Project
	*
	* 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 com.android.dex;

	import com.android.dex.util.ByteInput;

	/**
	* Pull parser for encoded values.
	*/
	public final class EncodedValueReader {
	public static final int ENCODED_BYTE = 0x00;
	public static final int ENCODED_SHORT = 0x02;
	public static final int ENCODED_CHAR = 0x03;
	public static final int ENCODED_INT = 0x04;
	public static final int ENCODED_LONG = 0x06;
	public static final int ENCODED_FLOAT = 0x10;
	public static final int ENCODED_DOUBLE = 0x11;
	public static final int ENCODED_STRING = 0x17;
	public static final int ENCODED_TYPE = 0x18;
	public static final int ENCODED_FIELD = 0x19;
	public static final int ENCODED_ENUM = 0x1b;
	public static final int ENCODED_METHOD = 0x1a;
	public static final int ENCODED_ARRAY = 0x1c;
	public static final int ENCODED_ANNOTATION = 0x1d;
	public static final int ENCODED_NULL = 0x1e;
	public static final int ENCODED_BOOLEAN = 0x1f;

	/** placeholder type if the type is not yet known */
	private static final int MUST_READ = -1;

	protected final ByteInput in;
	private int type = MUST_READ;
	private int annotationType;
	private int arg;

	public EncodedValueReader(ByteInput in) {
	this.in = in;
	}

	public EncodedValueReader(EncodedValue in) {
	this(in.asByteInput());
	}

	/**
	* Creates a new encoded value reader whose only value is the specified
	* known type. This is useful for encoded values without a type prefix,
	* such as class_def_item's encoded_array or annotation_item's
	* encoded_annotation.
	*/
	public EncodedValueReader(ByteInput in, int knownType) {
	this.in = in;
	this.type = knownType;
	}

	public EncodedValueReader(EncodedValue in, int knownType) {
	this(in.asByteInput(), knownType);
	}

	/**
	* Returns the type of the next value to read.
	*/
	public int peek() {
	if (type == MUST_READ) {
	int argAndType = in.readByte() & 0xff;
	type = argAndType & 0x1f;
	arg = (argAndType & 0xe0) >> 5;
	}
	return type;
	}

	/**
	* Begins reading the elements of an array, returning the array's size. The
	* caller must follow up by calling a read method for each element in the
	* array. For example, this reads a byte array: <pre> {@code
	* int arraySize = readArray();
	* for (int i = 0, i < arraySize; i++) {
	* readByte();
	* }
	* }</pre>
	*/
	public int readArray() {
	checkType(ENCODED_ARRAY);
	type = MUST_READ;
	return Leb128.readUnsignedLeb128(in);
	}

	/**
	* Begins reading the fields of an annotation, returning the number of
	* fields. The caller must follow up by making alternating calls to {@link
	* #readAnnotationName()} and another read method. For example, this reads
	* an annotation whose fields are all bytes: <pre> {@code
	* int fieldCount = readAnnotation();
	* int annotationType = getAnnotationType();
	* for (int i = 0; i < fieldCount; i++) {
	* readAnnotationName();
	* readByte();
	* }
	* }</pre>
	*/
	public int readAnnotation() {
	checkType(ENCODED_ANNOTATION);
	type = MUST_READ;
	annotationType = Leb128.readUnsignedLeb128(in);
	return Leb128.readUnsignedLeb128(in);
	}

	/**
	* Returns the type of the annotation just returned by {@link
	* #readAnnotation()}. This method's value is undefined unless the most
	* recent call was to {@link #readAnnotation()}.
	*/
	public int getAnnotationType() {
	return annotationType;
	}

	public int readAnnotationName() {
	return Leb128.readUnsignedLeb128(in);
	}

	public byte readByte() {
	checkType(ENCODED_BYTE);
	type = MUST_READ;
	return (byte) EncodedValueCodec.readSignedInt(in, arg);
	}

	public short readShort() {
	checkType(ENCODED_SHORT);
	type = MUST_READ;
	return (short) EncodedValueCodec.readSignedInt(in, arg);
	}

	public char readChar() {
	checkType(ENCODED_CHAR);
	type = MUST_READ;
	return (char) EncodedValueCodec.readUnsignedInt(in, arg, false);
	}

	public int readInt() {
	checkType(ENCODED_INT);
	type = MUST_READ;
	return EncodedValueCodec.readSignedInt(in, arg);
	}

	public long readLong() {
	checkType(ENCODED_LONG);
	type = MUST_READ;
	return EncodedValueCodec.readSignedLong(in, arg);
	}

	public float readFloat() {
	checkType(ENCODED_FLOAT);
	type = MUST_READ;
	return Float.intBitsToFloat(EncodedValueCodec.readUnsignedInt(in, arg, true));
	}

	public double readDouble() {
	checkType(ENCODED_DOUBLE);
	type = MUST_READ;
	return Double.longBitsToDouble(EncodedValueCodec.readUnsignedLong(in, arg, true));
	}

	public int readString() {
	checkType(ENCODED_STRING);
	type = MUST_READ;
	return EncodedValueCodec.readUnsignedInt(in, arg, false);
	}

	public int readType() {
	checkType(ENCODED_TYPE);
	type = MUST_READ;
	return EncodedValueCodec.readUnsignedInt(in, arg, false);
	}

	public int readField() {
	checkType(ENCODED_FIELD);
	type = MUST_READ;
	return EncodedValueCodec.readUnsignedInt(in, arg, false);
	}

	public int readEnum() {
	checkType(ENCODED_ENUM);
	type = MUST_READ;
	return EncodedValueCodec.readUnsignedInt(in, arg, false);
	}

	public int readMethod() {
	checkType(ENCODED_METHOD);
	type = MUST_READ;
	return EncodedValueCodec.readUnsignedInt(in, arg, false);
	}

	public void readNull() {
	checkType(ENCODED_NULL);
	type = MUST_READ;
	}

	public boolean readBoolean() {
	checkType(ENCODED_BOOLEAN);
	type = MUST_READ;
	return arg != 0;
	}

	/**
	* Skips a single value, including its nested values if it is an array or
	* annotation.
	*/
	public void skipValue() {
	switch (peek()) {
	case ENCODED_BYTE:
	readByte();
	break;
	case ENCODED_SHORT:
	readShort();
	break;
	case ENCODED_CHAR:
	readChar();
	break;
	case ENCODED_INT:
	readInt();
	break;
	case ENCODED_LONG:
	readLong();
	break;
	case ENCODED_FLOAT:
	readFloat();
	break;
	case ENCODED_DOUBLE:
	readDouble();
	break;
	case ENCODED_STRING:
	readString();
	break;
	case ENCODED_TYPE:
	readType();
	break;
	case ENCODED_FIELD:
	readField();
	break;
	case ENCODED_ENUM:
	readEnum();
	break;
	case ENCODED_METHOD:
	readMethod();
	break;
	case ENCODED_ARRAY:
	for (int i = 0, size = readArray(); i < size; i++) {
	skipValue();
	}
	break;
	case ENCODED_ANNOTATION:
	for (int i = 0, size = readAnnotation(); i < size; i++) {
	readAnnotationName();
	skipValue();
	}
	break;
	case ENCODED_NULL:
	readNull();
	break;
	case ENCODED_BOOLEAN:
	readBoolean();
	break;
	default:
	throw new DexException("Unexpected type: " + Integer.toHexString(type));
	}
	}

	private void checkType(int expected) {
	if (peek() != expected) {
	throw new IllegalStateException(
	String.format("Expected %x but was %x", expected, peek()));
	}
	}
	}