package org.jf.dexlib2.dexbacked;
import org.jf.util.ExceptionWithContext;
import javax.annotation.Nonnull;
import java.util.Arrays;
public class DexBuffer {
@Nonnull final byte[] buf;
final int baseOffset;
public DexBuffer(@Nonnull byte[] buf) {
this(buf, 0);
}
public DexBuffer(@Nonnull byte[] buf, int offset) {
this.buf = buf;
this.baseOffset = offset;
}
public int readSmallUint(int offset) {
byte[] buf = this.buf;
offset += baseOffset;
int result = (buf[offset] & 0xff) |
((buf[offset+1] & 0xff) << 8) |
((buf[offset+2] & 0xff) << 16) |
((buf[offset+3]) << 24);
if (result < 0) {
throw new ExceptionWithContext("Encountered small uint that is out of range at offset 0x%x", offset);
}
return result;
}
public int readOptionalUint(int offset) {
byte[] buf = this.buf;
offset += baseOffset;
int result = (buf[offset] & 0xff) |
((buf[offset+1] & 0xff) << 8) |
((buf[offset+2] & 0xff) << 16) |
((buf[offset+3]) << 24);
if (result < -1) {
throw new ExceptionWithContext("Encountered optional uint that is out of range at offset 0x%x", offset);
}
return result;
}
public int readUshort(int offset) {
byte[] buf = this.buf;
offset += baseOffset;
return (buf[offset] & 0xff) |
((buf[offset+1] & 0xff) << 8);
}
public int readUbyte(int offset) {
return buf[offset + baseOffset] & 0xff;
}
public long readLong(int offset) {
byte[] buf = this.buf;
offset += baseOffset;
return (buf[offset] & 0xff) |
((buf[offset+1] & 0xff) << 8) |
((buf[offset+2] & 0xff) << 16) |
((buf[offset+3] & 0xffL) << 24) |
((buf[offset+4] & 0xffL) << 32) |
((buf[offset+5] & 0xffL) << 40) |
((buf[offset+6] & 0xffL) << 48) |
(((long)buf[offset+7]) << 56);
}
public int readLongAsSmallUint(int offset) {
byte[] buf = this.buf;
offset += baseOffset;
long result = (buf[offset] & 0xff) |
((buf[offset+1] & 0xff) << 8) |
((buf[offset+2] & 0xff) << 16) |
((buf[offset+3] & 0xffL) << 24) |
((buf[offset+4] & 0xffL) << 32) |
((buf[offset+5] & 0xffL) << 40) |
((buf[offset+6] & 0xffL) << 48) |
(((long)buf[offset+7]) << 56);
if (result < 0 || result > Integer.MAX_VALUE) {
throw new ExceptionWithContext("Encountered out-of-range ulong at offset 0x%x", offset);
}
return (int)result;
}
public int readInt(int offset) {
byte[] buf = this.buf;
offset += baseOffset;
return (buf[offset] & 0xff) |
((buf[offset+1] & 0xff) << 8) |
((buf[offset+2] & 0xff) << 16) |
(buf[offset+3] << 24);
}
public int readShort(int offset) {
byte[] buf = this.buf;
offset += baseOffset;
return (buf[offset] & 0xff) |
(buf[offset+1] << 8);
}
public int readByte(int offset) {
return buf[baseOffset + offset];
}
@Nonnull
public byte[] readByteRange(int start, int length) {
return Arrays.copyOfRange(buf, baseOffset + start, baseOffset + start + length);
}
@Nonnull
public DexReader<? extends DexBuffer> readerAt(int offset) {
return new DexReader<DexBuffer>(this, offset);
}
@Nonnull
public byte[] getBuf() {
return buf;
}
public int getBaseOffset() {
return baseOffset;
}
}