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KaitaiStream.java
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KaitaiStream.java
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/**
* Copyright 2015-2024 Kaitai Project: MIT license
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package io.kaitai.struct;
import java.io.ByteArrayOutputStream;
import java.io.Closeable;
import java.io.EOFException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.zip.DataFormatException;
import java.util.zip.Inflater;
import java.util.zip.Deflater;
/**
* KaitaiStream provides implementation of
* <a href="https://doc.kaitai.io/stream_api.html">Kaitai Stream API</a>
* for Java.
*
* It provides a wide variety of simple methods to read (parse) binary
* representations of primitive types, such as integer and floating
* point numbers, byte arrays and strings, and also provides stream
* positioning / navigation methods with unified cross-language and
* cross-toolkit semantics.
*
* This is abstract class, which serves as an interface description and
* a few default method implementations, which are believed to be common
* for all (or at least most) implementations. Different implementations
* of this interface may provide way to parse data from local files,
* in-memory buffers or arrays, remote files, network streams, etc.
*
* Typically, end users won't access any of these Kaitai Stream classes
* manually, but would describe a binary structure format using .ksy language
* and then would use Kaitai Struct compiler to generate source code in
* desired target language. That code, in turn, would use this class
* and API to do the actual parsing job.
*/
public abstract class KaitaiStream implements Closeable {
protected int bitsLeft = 0;
protected long bits = 0;
protected boolean bitsLe = false;
protected boolean bitsWriteMode = false;
protected WriteBackHandler writeBackHandler;
protected List<KaitaiStream> childStreams = new ArrayList<>();
@Override
abstract public void close() throws IOException;
//region Stream positioning
/**
* Check if stream pointer is at the end of stream.
* @return true if we are located at the end of the stream
*/
abstract public boolean isEof();
/**
* Set stream pointer to designated position (int).
* @param newPos new position (offset in bytes from the beginning of the stream)
*/
abstract public void seek(int newPos);
/**
* Set stream pointer to designated position (long).
* @param newPos new position (offset in bytes from the beginning of the stream)
*/
abstract public void seek(long newPos);
/**
* Get current position of a stream pointer.
* @return pointer position, number of bytes from the beginning of the stream
*/
abstract public int pos();
/**
* Get total size of the stream in bytes.
* @return size of the stream in bytes
*/
abstract public long size();
//endregion
//region Reading
//region Integer numbers
//region Signed
/**
* Reads one signed 1-byte integer, returning it properly as Java's "byte" type.
* @return 1-byte integer read from a stream
*/
abstract public byte readS1();
//region Big-endian
abstract public short readS2be();
abstract public int readS4be();
abstract public long readS8be();
//endregion
//region Little-endian
abstract public short readS2le();
abstract public int readS4le();
abstract public long readS8le();
//endregion
//endregion
//region Unsigned
abstract public int readU1();
//region Big-endian
abstract public int readU2be();
abstract public long readU4be();
/**
* Reads one unsigned 8-byte integer in big-endian encoding. As Java does not
* have a primitive data type to accomodate it, we just reuse {@link #readS8be()}.
* @return 8-byte signed integer (pretending to be unsigned) read from a stream
*/
public long readU8be() {
return readS8be();
}
//endregion
//region Little-endian
abstract public int readU2le();
abstract public long readU4le();
/**
* Reads one unsigned 8-byte integer in little-endian encoding. As Java does not
* have a primitive data type to accomodate it, we just reuse {@link #readS8le()}.
* @return 8-byte signed integer (pretending to be unsigned) read from a stream
*/
public long readU8le() {
return readS8le();
}
//endregion
//endregion
//endregion
//region Floating point numbers
//region Big-endian
abstract public float readF4be();
abstract public double readF8be();
//endregion
//region Little-endian
abstract public float readF4le();
abstract public double readF8le();
//endregion
//endregion
//region Unaligned bit values
public void alignToByte() {
bitsLeft = 0;
bits = 0;
}
public long readBitsIntBe(int n) {
bitsWriteMode = false;
long res = 0;
int bitsNeeded = n - bitsLeft;
bitsLeft = -bitsNeeded & 7; // `-bitsNeeded mod 8`
if (bitsNeeded > 0) {
// 1 bit => 1 byte
// 8 bits => 1 byte
// 9 bits => 2 bytes
int bytesNeeded = ((bitsNeeded - 1) / 8) + 1; // `ceil(bitsNeeded / 8)`
byte[] buf = readBytesNotAligned(bytesNeeded);
for (byte b : buf) {
// `b` is signed byte, convert to unsigned using the "& 0xff" trick
res = res << 8 | (b & 0xff);
}
long newBits = res;
res = res >>> bitsLeft | (bitsNeeded < 64 ? bits << bitsNeeded : 0);
bits = newBits; // will be masked at the end of the function
} else {
res = bits >>> -bitsNeeded; // shift unneeded bits out
}
long mask = (1L << bitsLeft) - 1; // `bitsLeft` is in range 0..7, so `(1L << 64)` does not have to be considered
bits &= mask;
return res;
}
/**
* Unused since Kaitai Struct Compiler v0.9+ - compatibility with older versions
*
* @deprecated use {@link #readBitsIntBe(int)} instead
*/
@Deprecated
public long readBitsInt(int n) {
return readBitsIntBe(n);
}
public long readBitsIntLe(int n) {
bitsWriteMode = false;
long res = 0;
int bitsNeeded = n - bitsLeft;
if (bitsNeeded > 0) {
// 1 bit => 1 byte
// 8 bits => 1 byte
// 9 bits => 2 bytes
int bytesNeeded = ((bitsNeeded - 1) / 8) + 1; // `ceil(bitsNeeded / 8)`
byte[] buf = readBytesNotAligned(bytesNeeded);
for (int i = 0; i < bytesNeeded; i++) {
// `buf[i]` is signed byte, convert to unsigned using the "& 0xff" trick
res |= ((long) (buf[i] & 0xff)) << (i * 8);
}
// NB: in Java, bit shift operators on left-hand operand of type `long` work
// as if the right-hand operand were subjected to `& 63` (`& 0b11_1111`) (see
// https://docs.oracle.com/javase/specs/jls/se7/html/jls-15.html#jls-15.19),
// so `res >>> 64` is equivalent to `res >>> 0` (but we don't want that)
long newBits = bitsNeeded < 64 ? res >>> bitsNeeded : 0;
res = res << bitsLeft | bits;
bits = newBits;
} else {
res = bits;
bits >>>= n;
}
bitsLeft = -bitsNeeded & 7; // `-bitsNeeded mod 8`
if (n < 64) {
long mask = (1L << n) - 1;
res &= mask;
}
// if `n == 64`, do nothing
return res;
}
//endregion
//region Byte arrays
/**
* Reads designated number of bytes from the stream.
* @param n number of bytes to read
* @return read bytes as byte array
*/
public byte[] readBytes(long n) {
alignToByte();
return readBytesNotAligned(n);
}
/**
* Internal method to read the specified number of bytes from the stream. Unlike
* {@link #readBytes(long)}, it doesn't align the bit position to the next byte
* boundary.
* @param n number of bytes to read
* @return read bytes as a byte array
*/
abstract protected byte[] readBytesNotAligned(long n);
/**
* Reads all the remaining bytes in a stream as byte array.
* @return all remaining bytes in a stream as byte array
*/
abstract public byte[] readBytesFull();
abstract public byte[] readBytesTerm(byte term, boolean includeTerm, boolean consumeTerm, boolean eosError);
abstract public byte[] readBytesTermMulti(byte[] term, boolean includeTerm, boolean consumeTerm, boolean eosError);
/**
* Checks that next bytes in the stream match match expected fixed byte array.
* It does so by determining number of bytes to compare, reading them, and doing
* the actual comparison. If they differ, throws a {@link UnexpectedDataError}
* runtime exception.
* @param expected contents to be expected
* @return read bytes as byte array, which are guaranteed to equal to expected
* @throws UnexpectedDataError if read data from stream isn't equal to given data
* @deprecated Not used anymore in favour of validators.
*/
@Deprecated
public byte[] ensureFixedContents(byte[] expected) {
byte[] actual = readBytes(expected.length);
if (!Arrays.equals(actual, expected))
throw new UnexpectedDataError(actual, expected);
return actual;
}
public static byte[] bytesStripRight(byte[] bytes, byte padByte) {
int newLen = bytes.length;
while (newLen > 0 && bytes[newLen - 1] == padByte)
newLen--;
return Arrays.copyOf(bytes, newLen);
}
public static byte[] bytesTerminate(byte[] bytes, byte term, boolean includeTerm) {
int newLen = 0;
int maxLen = bytes.length;
while (newLen < maxLen && bytes[newLen] != term)
newLen++;
if (includeTerm && newLen < maxLen)
newLen++;
return Arrays.copyOf(bytes, newLen);
}
public static byte[] bytesTerminateMulti(byte[] bytes, byte[] term, boolean includeTerm) {
int unitSize = term.length;
if (unitSize == 0) {
return new byte[0];
}
int len = bytes.length;
int iTerm = 0;
for (int iBytes = 0; iBytes < len;) {
if (bytes[iBytes] != term[iTerm]) {
iBytes += unitSize - iTerm;
iTerm = 0;
continue;
}
iBytes++;
iTerm++;
if (iTerm == unitSize) {
return Arrays.copyOf(bytes, iBytes - (includeTerm ? 0 : unitSize));
}
}
return Arrays.copyOf(bytes, bytes.length);
}
/**
* Checks if supplied number of bytes is a valid number of elements for Java
* byte array: converts it to int, if it is, or throws an exception if it is not.
* @param n number of bytes for byte array as long
* @return number of bytes, converted to int
*/
protected int toByteArrayLength(long n) {
if (n > Integer.MAX_VALUE) {
throw new IllegalArgumentException(
"Java byte arrays can be indexed only up to 31 bits, but " + n + " size was requested"
);
}
if (n < 0) {
throw new IllegalArgumentException(
"Byte array size can't be negative, but " + n + " size was requested"
);
}
return (int) n;
}
//endregion
//endregion
//region Writing
protected void ensureBytesLeftToWrite(long n, long pos) {
long bytesLeft = size() - pos;
if (n > bytesLeft) {
throw new RuntimeException(
new EOFException("requested to write " + n + " bytes, but only " + bytesLeft + " bytes left in the stream")
);
}
}
//region Integer numbers
//region Signed
/**
* Writes one signed 1-byte integer.
*/
abstract public void writeS1(byte v);
//region Big-endian
abstract public void writeS2be(short v);
abstract public void writeS4be(int v);
abstract public void writeS8be(long v);
//endregion
//region Little-endian
abstract public void writeS2le(short v);
abstract public void writeS4le(int v);
abstract public void writeS8le(long v);
//endregion
//endregion
//region Unsigned
public void writeU1(int v) {
writeS1((byte) v);
}
//region Big-endian
public void writeU2be(int v) {
writeS2be((short) v);
}
public void writeU4be(long v) {
writeS4be((int) v);
}
public void writeU8be(long v) {
writeS8be(v);
}
//endregion
//region Little-endian
public void writeU2le(int v) {
writeS2le((short) v);
}
public void writeU4le(long v) {
writeS4le((int) v);
}
public void writeU8le(long v) {
writeS8le(v);
}
//endregion
//endregion
//endregion
//region Floating point numbers
//region Big-endian
abstract public void writeF4be(float v);
abstract public void writeF8be(double v);
//endregion
//region Little-endian
abstract public void writeF4le(float v);
abstract public void writeF8le(double v);
//endregion
//endregion
//region Unaligned bit values
public void writeAlignToByte() {
if (bitsLeft > 0) {
byte b = (byte) bits;
if (!bitsLe) {
b <<= 8 - bitsLeft;
}
// See https://github.com/kaitai-io/kaitai_struct_python_runtime/blob/704995ac/kaitaistruct.py#L572-L596
// for an explanation of why we call alignToByte() before
// writeBytesNotAligned().
alignToByte();
writeBytesNotAligned(new byte[] { b });
}
}
/*
Example 1 (bytesToWrite > 0):
old bitsLeft = 5
| | new bitsLeft = 18 mod 8 = 2
/ \ /\
|01101xxx|xxxxxxxx|xx......|
\ \ /
\ \__ n = 13 _/
\ /
\____________/
bitsToWrite = 18 -> bytesToWrite = 2
---
Example 2 (bytesToWrite == 0):
old bitsLeft = 1
| |
\ /
|01101100|1xxxxx..|........|
/ \___/\
/ n = 5 \
/__________\
bitsToWrite = 6 -> bytesToWrite = 0,
new bitsLeft = 6 mod 8 = 6
*/
public void writeBitsIntBe(int n, long val) {
bitsLe = false;
bitsWriteMode = true;
if (n < 64) {
long mask = (1L << n) - 1;
val &= mask;
}
// if `n == 64`, do nothing
int bitsToWrite = bitsLeft + n;
int bytesNeeded = ((bitsToWrite - 1) / 8) + 1; // `ceil(bitsToWrite / 8)`
// pos() respects the `bitsLeft` field (it returns the stream position
// as if it were already aligned on a byte boundary), which ensures that
// we report the same numbers of bytes here as readBitsInt*() methods
// would.
ensureBytesLeftToWrite(bytesNeeded - (bitsLeft > 0 ? 1 : 0), pos());
int bytesToWrite = bitsToWrite / 8;
bitsLeft = bitsToWrite & 7; // `bitsToWrite mod 8`
if (bytesToWrite > 0) {
byte[] buf = new byte[bytesToWrite];
long mask = (1L << bitsLeft) - 1; // `bitsLeft` is in range 0..7, so `(1L << 64)` does not have to be considered
long newBits = val & mask;
val = val >>> bitsLeft | (n - bitsLeft < 64 ? bits << (n - bitsLeft) : 0);
bits = newBits;
for (int i = bytesToWrite - 1; i >= 0; i--) {
buf[i] = (byte) (val & 0xff);
val >>>= 8;
}
writeBytesNotAligned(buf);
} else {
bits = bits << n | val;
}
}
/*
Example 1 (bytesToWrite > 0):
n = 13
old bitsLeft = 5
| | new bitsLeft = 18 mod 8 = 2
/ \ /\
|xxx01101|xxxxxxxx|......xx|
\ / / /
--------------- --
\ /
bitsToWrite = 18 -> bytesToWrite = 2
---
Example 2 (bytesToWrite == 0):
old bitsLeft = 1
| |
\ /
|01101100|..xxxxx1|........|
/\___/ \
/ n = 5 \
/__________\
bitsToWrite = 6 -> bytesToWrite = 0,
new bitsLeft = 6 mod 8 = 6
*/
public void writeBitsIntLe(int n, long val) {
bitsLe = true;
bitsWriteMode = true;
int bitsToWrite = bitsLeft + n;
int bytesNeeded = ((bitsToWrite - 1) / 8) + 1; // `ceil(bitsToWrite / 8)`
// pos() respects the `bitsLeft` field (it returns the stream position
// as if it were already aligned on a byte boundary), which ensures that
// we report the same numbers of bytes here as readBitsInt*() methods
// would.
ensureBytesLeftToWrite(bytesNeeded - (bitsLeft > 0 ? 1 : 0), pos());
int bytesToWrite = bitsToWrite / 8;
int oldBitsLeft = bitsLeft;
bitsLeft = bitsToWrite & 7; // `bitsToWrite mod 8`
if (bytesToWrite > 0) {
byte[] buf = new byte[bytesToWrite];
long newBits = n - bitsLeft < 64 ? val >>> (n - bitsLeft) : 0;
val = val << oldBitsLeft | bits;
bits = newBits;
for (int i = 0; i < bytesToWrite; i++) {
buf[i] = (byte) (val & 0xff);
val >>>= 8;
}
writeBytesNotAligned(buf);
} else {
bits |= val << oldBitsLeft;
}
long mask = (1L << bitsLeft) - 1; // `bitsLeft` is in range 0..7, so `(1L << 64)` does not have to be considered
bits &= mask;
}
//endregion
//region Byte arrays
/**
* Writes given byte array to the stream.
* @param buf byte array to write
*/
public void writeBytes(byte[] buf) {
writeAlignToByte();
writeBytesNotAligned(buf);
}
/**
* Internal method to write the given byte array to the stream. Unlike
* {@link #writeBytes(byte[])}, it doesn't align the bit position to the next byte
* boundary.
* @param buf byte array to write
*/
abstract protected void writeBytesNotAligned(byte[] buf);
public void writeBytesLimit(byte[] buf, long size, byte term, byte padByte) {
int len = buf.length;
writeBytes(buf);
if (len < size) {
writeS1(term);
long padLen = size - len - 1;
for (long i = 0; i < padLen; i++)
writeS1(padByte);
} else if (len > size) {
throw new IllegalArgumentException(
"Writing " + size + " bytes, but " + len + " bytes were given"
);
}
}
public void writeStream(KaitaiStream other) {
writeBytes(other.toByteArray());
}
//endregion
//endregion
//region Byte array processing
/**
* Performs a XOR processing with given data, XORing every byte of input with a single
* given value.
* @param data data to process
* @param key value to XOR with
* @return processed data
*/
public static byte[] processXor(byte[] data, byte key) {
int dataLen = data.length;
byte[] r = new byte[dataLen];
for (int i = 0; i < dataLen; i++)
r[i] = (byte) (data[i] ^ key);
return r;
}
/**
* Performs a XOR processing with given data, XORing every byte of input with a key
* array, repeating key array many times, if necessary (i.e. if data array is longer
* than key array).
* @param data data to process
* @param key array of bytes to XOR with
* @return processed data
*/
public static byte[] processXor(byte[] data, byte[] key) {
int dataLen = data.length;
int valueLen = key.length;
byte[] r = new byte[dataLen];
int j = 0;
for (int i = 0; i < dataLen; i++) {
r[i] = (byte) (data[i] ^ key[j]);
j = (j + 1) % valueLen;
}
return r;
}
/**
* Performs a circular left rotation shift for a given buffer by a given amount of bits,
* using groups of groupSize bytes each time. Right circular rotation should be performed
* using this procedure with corrected amount.
* @param data source data to process
* @param amount number of bits to shift by
* @param groupSize number of bytes per group to shift
* @return copy of source array with requested shift applied
*/
public static byte[] processRotateLeft(byte[] data, int amount, int groupSize) {
byte[] r = new byte[data.length];
switch (groupSize) {
case 1:
for (int i = 0; i < data.length; i++) {
byte bits = data[i];
// http://stackoverflow.com/a/19181827/487064
r[i] = (byte) (((bits & 0xff) << amount) | ((bits & 0xff) >>> (8 - amount)));
}
break;
default:
throw new UnsupportedOperationException("unable to rotate group of " + groupSize + " bytes yet");
}
return r;
}
private final static int ZLIB_BUF_SIZE = 4096;
/**
* Performs an unpacking ("inflation") of zlib-compressed data with usual zlib headers.
* @param data data to unpack
* @return unpacked data
* @throws RuntimeException if data can't be decoded
*/
public static byte[] processZlib(byte[] data) {
Inflater ifl = new Inflater();
ifl.setInput(data);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte buf[] = new byte[ZLIB_BUF_SIZE];
while (!ifl.finished()) {
try {
int decBytes = ifl.inflate(buf);
baos.write(buf, 0, decBytes);
} catch (DataFormatException e) {
throw new RuntimeException(e);
}
}
ifl.end();
return baos.toByteArray();
}
public static byte[] unprocessZlib(byte[] data) {
Deflater dfl = new Deflater();
dfl.setInput(data);
dfl.finish();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte buf[] = new byte[ZLIB_BUF_SIZE];
while (!dfl.finished()) {
int decBytes = dfl.deflate(buf);
baos.write(buf, 0, decBytes);
}
dfl.end();
return baos.toByteArray();
}
//endregion
//region Misc runtime operations
/**
* Reserves next `n` bytes from current stream as a KaitaiStream-compatible substream.
* Substream has its own pointer and addressing in the range of [0, n) bytes. This
* stream's pointer is advanced to the position right after this substream.
* @param n number of bytes to reserve for a substream
* @return substream covering n bytes from the current position
*/
abstract public KaitaiStream substream(long n);
/**
* Performs modulo operation between two integers: dividend `a`
* and divisor `b`. Divisor `b` is expected to be positive. The
* result is always 0 <= x <= b - 1.
* @param a dividend
* @param b divisor
* @return result
*/
public static int mod(int a, int b) {
if (b <= 0)
throw new ArithmeticException("mod divisor <= 0");
int r = a % b;
if (r < 0)
r += b;
return r;
}
/**
* Performs modulo operation between two integers: dividend `a`
* and divisor `b`. Divisor `b` is expected to be positive. The
* result is always 0 <= x <= b - 1.
* @param a dividend
* @param b divisor
* @return result
*/
public static long mod(long a, long b) {
if (b <= 0)
throw new ArithmeticException("mod divisor <= 0");
long r = a % b;
if (r < 0)
r += b;
return r;
}
/**
* Compares two byte arrays in lexicographical order. Makes extra effort
* to compare bytes properly, as *unsigned* bytes, i.e. [0x90] would be
* greater than [0x10].
* @param a first byte array to compare
* @param b second byte array to compare
* @return negative number if a < b, 0 if a == b, positive number if a > b
* @see Comparable#compareTo(Object)
*/
public static int byteArrayCompare(byte[] a, byte[] b) {
if (a == b)
return 0;
int al = a.length;
int bl = b.length;
int minLen = Math.min(al, bl);
for (int i = 0; i < minLen; i++) {
int cmp = (a[i] & 0xff) - (b[i] & 0xff);
if (cmp != 0)
return cmp;
}
// Reached the end of at least one of the arrays
if (al == bl) {
return 0;
} else {
return al - bl;
}
}
/**
* Finds the minimal byte in a byte array, treating bytes as
* unsigned values.
* @param b byte array to scan
* @return minimal byte in byte array as integer
*/
public static int byteArrayMin(byte[] b) {
int min = Integer.MAX_VALUE;
for (int i = 0; i < b.length; i++) {
int value = b[i] & 0xff;
if (value < min)
min = value;
}
return min;
}
/**
* Finds the maximal byte in a byte array, treating bytes as
* unsigned values.
* @param b byte array to scan
* @return maximal byte in byte array as integer
*/
public static int byteArrayMax(byte[] b) {
int max = 0;
for (int i = 0; i < b.length; i++) {
int value = b[i] & 0xff;
if (value > max)
max = value;
}
return max;
}
/**
* Returns the index of the first occurrence of the specified byte in a byte
* array, or -1 if this byte array does not contain the byte.
*
* @param arr byte array to search in
* @param b byte to search for
* @return index of the first occurrence of the specified byte in the byte
* array, or -1 if this byte array does not contain the byte
* @see java.util.List#indexOf(Object)
* @see String#indexOf(int)
*/
public static int byteArrayIndexOf(byte[] arr, byte b) {
int len = arr.length;
for (int i = 0; i < len; i++) {
if (arr[i] == b) {
return i;
}
}
return -1;
}
static String byteArrayToHex(byte[] arr) {
StringBuilder sb = new StringBuilder("[");
for (int i = 0; i < arr.length; i++) {
if (i > 0)
sb.append(' ');
sb.append(String.format("%02x", arr[i]));
}
sb.append(']');
return sb.toString();
}
//endregion
public byte[] toByteArray() {
long pos = pos();
seek(0);
byte[] r = readBytesFull();
seek(pos);
return r;
}
public abstract static class WriteBackHandler {
protected final long pos;
public WriteBackHandler(long pos) {
this.pos = pos;
}
public void writeBack(KaitaiStream parent) {
parent.seek(pos);
write(parent);
}
protected abstract void write(KaitaiStream parent);
}
public void setWriteBackHandler(WriteBackHandler handler) {
writeBackHandler = handler;
}
public void addChildStream(KaitaiStream child) {
childStreams.add(child);
}
public void writeBackChildStreams() {
writeBackChildStreams(null);
}
protected void writeBackChildStreams(KaitaiStream parent) {
final long _pos = pos();
for (KaitaiStream child : childStreams) {
child.writeBackChildStreams(this);
}
childStreams.clear();
seek(_pos);
if (parent != null) {
writeBack(parent);
}
}
protected void writeBack(KaitaiStream parent) {
writeBackHandler.writeBack(parent);
}
/**
* Exception class for an error that occurs when some fixed content
* was expected to appear, but actual data read was different.
*
* @deprecated Not used anymore in favour of {@code Validation*}-exceptions.
*/
@Deprecated
public static class UnexpectedDataError extends RuntimeException {
public UnexpectedDataError(byte[] actual, byte[] expected) {
super(
"Unexpected fixed contents: got " + byteArrayToHex(actual) +