package com.esotericsoftware.kryo.io;
import java.io.IOException;
import java.io.InputStream;
import com.esotericsoftware.kryo.KryoException;
/** An InputStream that reads data from a byte array and optionally fills the byte array from another OutputStream as needed.
* Utility methods are provided for efficiently reading primitive types and strings.
* @author Nathan Sweet <misc@n4te.com> */
public class Input extends InputStream {
private byte[] buffer;
private int capacity, position, limit, total;
private char[] chars = new char[32];
private InputStream inputStream;
/** Creates an uninitialized Input. {@link #setBuffer(byte[])} must be called before the Input is used. */
public Input () {
}
/** Creates a new Input for reading from a byte array.
* @param bufferSize The size of the buffer. An exception is thrown if more bytes than this are read. */
public Input (int bufferSize) {
this.capacity = bufferSize;
buffer = new byte[bufferSize];
}
/** Creates a new Input for reading from a byte array.
* @param buffer An exception is thrown if more bytes than this are read. */
public Input (byte[] buffer) {
setBuffer(buffer, 0, buffer.length);
}
/** Creates a new Input for reading from a byte array.
* @param buffer An exception is thrown if more bytes than this are read. */
public Input (byte[] buffer, int offset, int count) {
setBuffer(buffer, offset, count);
}
/** Creates a new Input for reading from an InputStream with a buffer size of 4096. */
public Input (InputStream inputStream) {
this(4096);
if (inputStream == null) throw new IllegalArgumentException("inputStream cannot be null.");
this.inputStream = inputStream;
}
/** Creates a new Input for reading from an InputStream. */
public Input (InputStream inputStream, int bufferSize) {
this(bufferSize);
if (inputStream == null) throw new IllegalArgumentException("inputStream cannot be null.");
this.inputStream = inputStream;
}
/** Sets a new buffer. The position and total are reset, discarding any buffered bytes. */
public void setBuffer (byte[] bytes) {
setBuffer(bytes, 0, bytes.length);
}
/** Sets a new buffer. The position and total are reset, discarding any buffered bytes. */
public void setBuffer (byte[] bytes, int offset, int count) {
if (bytes == null) throw new IllegalArgumentException("bytes cannot be null.");
buffer = bytes;
position = offset;
limit = count;
capacity = bytes.length;
total = 0;
inputStream = null;
}
public byte[] getBuffer () {
return buffer;
}
public InputStream getInputStream () {
return inputStream;
}
/** Sets a new InputStream. The position and total are reset, discarding any buffered bytes.
* @param inputStream May be null. */
public void setInputStream (InputStream inputStream) {
this.inputStream = inputStream;
limit = 0;
rewind();
}
/** Returns the number of bytes read. */
public int total () {
return total + position;
}
/** Returns the current position in the buffer. */
public int position () {
return position;
}
/** Sets the current position in the buffer. */
public void setPosition (int position) {
this.position = position;
}
/** Returns the limit for the buffer. */
public int limit () {
return limit;
}
/** Sets the limit in the buffer. */
public void setLimit (int limit) {
this.limit = limit;
}
/** Sets the position and total to zero. */
public void rewind () {
position = 0;
total = 0;
}
/** Discards the specified number of bytes. */
public void skip (int count) throws KryoException {
int skipCount = Math.min(limit - position, count);
while (true) {
position += skipCount;
count -= skipCount;
if (count == 0) break;
skipCount = Math.min(count, capacity);
require(skipCount);
}
}
/** Fills the buffer with more bytes. Can be overridden to fill the bytes from a source other than the InputStream. */
protected int fill (byte[] buffer, int offset, int count) throws KryoException {
if (inputStream == null) return -1;
try {
return inputStream.read(buffer, offset, count);
} catch (IOException ex) {
throw new KryoException(ex);
}
}
/** @param required Must be > 0. The buffer is filled until it has at least this many bytes.
* @return the number of bytes remaining.
* @throws KryoException if EOS is reached before required bytes are read (buffer underflow). */
private int require (int required) throws KryoException {
int remaining = limit - position;
if (remaining >= required) return remaining;
if (required > capacity) throw new KryoException("Buffer too small: capacity: " + capacity + ", required: " + required);
// Compact.
System.arraycopy(buffer, position, buffer, 0, remaining);
total += position;
position = 0;
while (true) {
int count = fill(buffer, remaining, capacity - remaining);
if (count == -1) {
if (remaining >= required) break;
throw new KryoException("Buffer underflow.");
}
remaining += count;
if (remaining >= required) break; // Enough has been read.
}
limit = remaining;
return remaining;
}
/** @param optional Try to fill the buffer with this many bytes.
* @return the number of bytes remaining, but not more than optional, or -1 if the EOS was reached and the buffer is empty. */
private int optional (int optional) throws KryoException {
int remaining = limit - position;
if (remaining >= optional) return optional;
optional = Math.min(optional, capacity);
// Compact.
System.arraycopy(buffer, position, buffer, 0, remaining);
total += position;
position = 0;
while (true) {
int count = fill(buffer, remaining, capacity - remaining);
if (count == -1) break;
remaining += count;
if (remaining >= optional) break; // Enough has been read.
}
limit = remaining;
return remaining == 0 ? -1 : Math.min(remaining, optional);
}
// InputStream
/** Reads a single byte as an int from 0 to 255, or -1 if there are no more bytes are available. */
public int read () throws KryoException {
if (optional(1) == 0) return -1;
return buffer[position++] & 0xFF;
}
/** Reads bytes.length bytes or less and writes them to the specified byte[], starting at 0, and returns the number of bytes
* read. */
public int read (byte[] bytes) throws KryoException {
return read(bytes, 0, bytes.length);
}
/** Reads count bytes or less and writes them to the specified byte[], starting at offset, and returns the number of bytes read
* or -1 if no more bytes are available. */
public int read (byte[] bytes, int offset, int count) throws KryoException {
if (bytes == null) throw new IllegalArgumentException("bytes cannot be null.");
int startingCount = count;
int copyCount = Math.min(limit - position, count);
while (true) {
System.arraycopy(buffer, position, bytes, offset, copyCount);
position += copyCount;
count -= copyCount;
if (count == 0) break;
offset += copyCount;
copyCount = optional(count);
if (copyCount == -1) {
// End of data.
if (startingCount == count) return -1;
break;
}
if (position == limit) break;
}
return startingCount - count;
}
/** Discards the specified number of bytes. */
public long skip (long count) throws KryoException {
long remaining = count;
while (remaining > 0) {
int skip = Math.max(Integer.MAX_VALUE, (int)remaining);
skip(skip);
remaining -= skip;
}
return count;
}
/** Closes the underlying InputStream, if any. */
public void close () throws KryoException {
if (inputStream != null) {
try {
inputStream.close();
} catch (IOException ignored) {
}
}
}
// byte
/** Reads a single byte. */
public byte readByte () throws KryoException {
require(1);
return buffer[position++];
}
/** Reads a byte as an int from 0 to 255. */
public int readByteUnsigned () throws KryoException {
require(1);
return buffer[position++] & 0xFF;
}
/** Reads the specified number of bytes into a new byte[]. */
public byte[] readBytes (int length) throws KryoException {
byte[] bytes = new byte[length];
readBytes(bytes, 0, length);
return bytes;
}
/** Reads bytes.length bytes and writes them to the specified byte[], starting at index 0. */
public void readBytes (byte[] bytes) throws KryoException {
readBytes(bytes, 0, bytes.length);
}
/** Reads count bytes and writes them to the specified byte[], starting at offset. */
public void readBytes (byte[] bytes, int offset, int count) throws KryoException {
if (bytes == null) throw new IllegalArgumentException("bytes cannot be null.");
int copyCount = Math.min(limit - position, count);
while (true) {
System.arraycopy(buffer, position, bytes, offset, copyCount);
position += copyCount;
count -= copyCount;
if (count == 0) break;
offset += copyCount;
copyCount = Math.min(count, capacity);
require(copyCount);
}
}
// int
/** Reads a 4 byte int. */
public int readInt () throws KryoException {
require(4);
byte[] buffer = this.buffer;
int position = this.position;
this.position = position + 4;
return (buffer[position] & 0xFF) << 24 //
| (buffer[position + 1] & 0xFF) << 16 //
| (buffer[position + 2] & 0xFF) << 8 //
| buffer[position + 3] & 0xFF;
}
/** Reads a 1-5 byte int. */
public int readInt (boolean optimizePositive) throws KryoException {
if (require(1) < 5) return readInt_slow(optimizePositive);
int b = buffer[position++];
int result = b & 0x7F;
if ((b & 0x80) != 0) {
byte[] buffer = this.buffer;
b = buffer[position++];
result |= (b & 0x7F) << 7;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (b & 0x7F) << 14;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (b & 0x7F) << 21;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (b & 0x7F) << 28;
}
}
}
}
return optimizePositive ? result : ((result >>> 1) ^ -(result & 1));
}
private int readInt_slow (boolean optimizePositive) {
// The buffer is guaranteed to have at least 1 byte.
int b = buffer[position++];
int result = b & 0x7F;
if ((b & 0x80) != 0) {
require(1);
byte[] buffer = this.buffer;
b = buffer[position++];
result |= (b & 0x7F) << 7;
if ((b & 0x80) != 0) {
require(1);
b = buffer[position++];
result |= (b & 0x7F) << 14;
if ((b & 0x80) != 0) {
require(1);
b = buffer[position++];
result |= (b & 0x7F) << 21;
if ((b & 0x80) != 0) {
require(1);
b = buffer[position++];
result |= (b & 0x7F) << 28;
}
}
}
}
return optimizePositive ? result : ((result >>> 1) ^ -(result & 1));
}
/** Returns true if enough bytes are available to read an int with {@link #readInt(boolean)}. */
public boolean canReadInt () throws KryoException {
if (limit - position >= 5) return true;
if (optional(5) <= 0) return false;
int p = position;
if ((buffer[p++] & 0x80) == 0) return true;
if (p == limit) return false;
if ((buffer[p++] & 0x80) == 0) return true;
if (p == limit) return false;
if ((buffer[p++] & 0x80) == 0) return true;
if (p == limit) return false;
if ((buffer[p++] & 0x80) == 0) return true;
if (p == limit) return false;
return true;
}
/** Returns true if enough bytes are available to read a long with {@link #readLong(boolean)}. */
public boolean canReadLong () throws KryoException {
if (limit - position >= 9) return true;
if (optional(5) <= 0) return false;
int p = position;
if ((buffer[p++] & 0x80) == 0) return true;
if (p == limit) return false;
if ((buffer[p++] & 0x80) == 0) return true;
if (p == limit) return false;
if ((buffer[p++] & 0x80) == 0) return true;
if (p == limit) return false;
if ((buffer[p++] & 0x80) == 0) return true;
if (p == limit) return false;
if ((buffer[p++] & 0x80) == 0) return true;
if (p == limit) return false;
if ((buffer[p++] & 0x80) == 0) return true;
if (p == limit) return false;
if ((buffer[p++] & 0x80) == 0) return true;
if (p == limit) return false;
if ((buffer[p++] & 0x80) == 0) return true;
if (p == limit) return false;
return true;
}
// string
/** Reads the length and string of UTF8 characters, or null. This can read strings written by {@link Output#writeString(String)}
* , {@link Output#writeString(CharSequence)}, and {@link Output#writeAscii(String)}.
* @return May be null. */
public String readString () {
int available = require(1);
int b = buffer[position++];
if ((b & 0x80) == 0) return readAscii(); // ASCII.
// Null, empty, or UTF8.
int charCount = available >= 5 ? readUtf8Length(b) : readUtf8Length_slow(b);
switch (charCount) {
case 0:
return null;
case 1:
return "";
}
charCount--;
if (chars.length < charCount) chars = new char[charCount];
readUtf8(charCount);
return new String(chars, 0, charCount);
}
private int readUtf8Length (int b) {
int result = b & 0x3F; // Mask all but first 6 bits.
if ((b & 0x40) != 0) { // Bit 7 means another byte, bit 8 means UTF8.
byte[] buffer = this.buffer;
b = buffer[position++];
result |= (b & 0x7F) << 6;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (b & 0x7F) << 13;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (b & 0x7F) << 20;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (b & 0x7F) << 27;
}
}
}
}
return result;
}
private int readUtf8Length_slow (int b) {
int result = b & 0x3F; // Mask all but first 6 bits.
if ((b & 0x40) != 0) { // Bit 7 means another byte, bit 8 means UTF8.
require(1);
byte[] buffer = this.buffer;
b = buffer[position++];
result |= (b & 0x7F) << 6;
if ((b & 0x80) != 0) {
require(1);
b = buffer[position++];
result |= (b & 0x7F) << 13;
if ((b & 0x80) != 0) {
require(1);
b = buffer[position++];
result |= (b & 0x7F) << 20;
if ((b & 0x80) != 0) {
require(1);
b = buffer[position++];
result |= (b & 0x7F) << 27;
}
}
}
}
return result;
}
private void readUtf8 (int charCount) {
byte[] buffer = this.buffer;
char[] chars = this.chars;
// Try to read 7 bit ASCII chars.
int charIndex = 0;
int count = Math.min(require(1), charCount);
int position = this.position;
int b;
while (charIndex < count) {
b = buffer[position++];
if (b < 0) {
position--;
break;
}
chars[charIndex++] = (char)b;
}
this.position = position;
// If buffer didn't hold all chars or any were not ASCII, use slow path for remainder.
if (charIndex < charCount) readUtf8_slow(charCount, charIndex);
}
private void readUtf8_slow (int charCount, int charIndex) {
char[] chars = this.chars;
byte[] buffer = this.buffer;
while (charIndex < charCount) {
if (position == limit) require(1);
int b = buffer[position++] & 0xFF;
switch (b >> 4) {
case 0:
case 1:
case 2:
case 3:
case 4:
case 5:
case 6:
case 7:
chars[charIndex] = (char)b;
break;
case 12:
case 13:
if (position == limit) require(1);
chars[charIndex] = (char)((b & 0x1F) << 6 | buffer[position++] & 0x3F);
break;
case 14:
require(2);
chars[charIndex] = (char)((b & 0x0F) << 12 | (buffer[position++] & 0x3F) << 6 | buffer[position++] & 0x3F);
break;
}
charIndex++;
}
}
private String readAscii () {
byte[] buffer = this.buffer;
int end = position;
int start = end - 1;
int limit = this.limit;
int b;
do {
if (end == limit) return readAscii_slow();
b = buffer[end++];
} while ((b & 0x80) == 0);
buffer[end - 1] &= 0x7F; // Mask end of ascii bit.
String value = new String(buffer, 0, start, end - start);
buffer[end - 1] |= 0x80;
position = end;
return value;
}
private String readAscii_slow () {
position--; // Re-read the first byte.
// Copy chars currently in buffer.
int charCount = limit - position;
if (charCount > chars.length) chars = new char[charCount * 2];
char[] chars = this.chars;
byte[] buffer = this.buffer;
for (int i = position, ii = 0, n = limit; i < n; i++, ii++)
chars[ii] = (char)buffer[i];
position = limit;
// Copy additional chars one by one.
while (true) {
require(1);
int b = buffer[position++];
if (charCount == chars.length) {
char[] newChars = new char[charCount * 2];
System.arraycopy(chars, 0, newChars, 0, charCount);
chars = newChars;
this.chars = newChars;
}
if ((b & 0x80) == 0x80) {
chars[charCount++] = (char)(b & 0x7F);
break;
}
chars[charCount++] = (char)b;
}
return new String(chars, 0, charCount);
}
/** Reads the length and string of UTF8 characters, or null. This can read strings written by {@link Output#writeString(String)}
* , {@link Output#writeString(CharSequence)}, and {@link Output#writeAscii(String)}.
* @return May be null. */
public StringBuilder readStringBuilder () {
int available = require(1);
int b = buffer[position++];
if ((b & 0x80) == 0) return new StringBuilder(readAscii()); // ASCII.
// Null, empty, or UTF8.
int charCount = available >= 5 ? readUtf8Length(b) : readUtf8Length_slow(b);
switch (charCount) {
case 0:
return null;
case 1:
return new StringBuilder("");
}
charCount--;
if (chars.length < charCount) chars = new char[charCount];
readUtf8(charCount);
StringBuilder builder = new StringBuilder(charCount);
builder.append(chars, 0, charCount);
return builder;
}
// float
/** Reads a 4 byte float. */
public float readFloat () throws KryoException {
return Float.intBitsToFloat(readInt());
}
/** Reads a 1-5 byte float with reduced precision. */
public float readFloat (float precision, boolean optimizePositive) throws KryoException {
return readInt(optimizePositive) / (float)precision;
}
// short
/** Reads a 2 byte short. */
public short readShort () throws KryoException {
require(2);
return (short)(((buffer[position++] & 0xFF) << 8) | (buffer[position++] & 0xFF));
}
/** Reads a 2 byte short as an int from 0 to 65535. */
public int readShortUnsigned () throws KryoException {
require(2);
return ((buffer[position++] & 0xFF) << 8) | (buffer[position++] & 0xFF);
}
// long
/** Reads an 8 byte long. */
public long readLong () throws KryoException {
require(8);
byte[] buffer = this.buffer;
return (long)buffer[position++] << 56 //
| (long)(buffer[position++] & 0xFF) << 48 //
| (long)(buffer[position++] & 0xFF) << 40 //
| (long)(buffer[position++] & 0xFF) << 32 //
| (long)(buffer[position++] & 0xFF) << 24 //
| (buffer[position++] & 0xFF) << 16 //
| (buffer[position++] & 0xFF) << 8 //
| buffer[position++] & 0xFF;
}
/** Reads a 1-9 byte long. */
public long readLong (boolean optimizePositive) throws KryoException {
if (require(1) < 9) return readLong_slow(optimizePositive);
int b = buffer[position++];
long result = b & 0x7F;
if ((b & 0x80) != 0) {
byte[] buffer = this.buffer;
b = buffer[position++];
result |= (b & 0x7F) << 7;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (b & 0x7F) << 14;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (b & 0x7F) << 21;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (long)(b & 0x7F) << 28;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (long)(b & 0x7F) << 35;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (long)(b & 0x7F) << 42;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (long)(b & 0x7F) << 49;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (long)b << 56;
}
}
}
}
}
}
}
}
if (!optimizePositive) result = (result >>> 1) ^ -(result & 1);
return result;
}
private long readLong_slow (boolean optimizePositive) {
// The buffer is guaranteed to have at least 1 byte.
int b = buffer[position++];
long result = b & 0x7F;
if ((b & 0x80) != 0) {
require(1);
byte[] buffer = this.buffer;
b = buffer[position++];
result |= (b & 0x7F) << 7;
if ((b & 0x80) != 0) {
require(1);
b = buffer[position++];
result |= (b & 0x7F) << 14;
if ((b & 0x80) != 0) {
require(1);
b = buffer[position++];
result |= (b & 0x7F) << 21;
if ((b & 0x80) != 0) {
require(1);
b = buffer[position++];
result |= (long)(b & 0x7F) << 28;
if ((b & 0x80) != 0) {
require(1);
b = buffer[position++];
result |= (long)(b & 0x7F) << 35;
if ((b & 0x80) != 0) {
require(1);
b = buffer[position++];
result |= (long)(b & 0x7F) << 42;
if ((b & 0x80) != 0) {
require(1);
b = buffer[position++];
result |= (long)(b & 0x7F) << 49;
if ((b & 0x80) != 0) {
require(1);
b = buffer[position++];
result |= (long)b << 56;
}
}
}
}
}
}
}
}
if (!optimizePositive) result = (result >>> 1) ^ -(result & 1);
return result;
}
// boolean
/** Reads a 1 byte boolean. */
public boolean readBoolean () throws KryoException {
require(1);
return buffer[position++] == 1;
}
// char
/** Reads a 2 byte char. */
public char readChar () throws KryoException {
require(2);
return (char)(((buffer[position++] & 0xFF) << 8) | (buffer[position++] & 0xFF));
}
// double
/** Reads an 8 bytes double. */
public double readDouble () throws KryoException {
return Double.longBitsToDouble(readLong());
}
/** Reads a 1-9 byte double with reduced precision. */
public double readDouble (double precision, boolean optimizePositive) throws KryoException {
return readLong(optimizePositive) / (double)precision;
}
}