/*
* Copyright (c) 2008-2014 MongoDB, Inc.
*
* 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 org.bson.io;
import org.bson.BSONException;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
/**
* An abstract base class for classes implementing {@code BsonOutput}.
*/
public abstract class OutputBuffer extends OutputStream {
@Override
public abstract void write(byte[] b);
@Override
public abstract void write(byte[] b, int off, int len);
@Override
public abstract void write(int b);
/**
* Gets the current position in the stream.
*
* @return the current position
*/
public abstract int getPosition();
/**
* @param position the position to set
* @deprecated This method is NOT a part of public API and will be dropped in 3.x versions.
*/
@Deprecated
public abstract void setPosition( int position );
/**
* @deprecated This method is NOT a part of public API and will be dropped in 3.x versions.
*/
@Deprecated
public abstract void seekEnd();
/**
* @deprecated This method is NOT a part of public API and will be dropped in 3.x versions.
*/
@Deprecated
public abstract void seekStart();
/**
* Gets the output size in bytes.
* @return the size
*/
public abstract int size();
/**
* Pipe the contents of this output buffer into the given output stream
*
* @param out the stream to pipe to
* @return number of bytes written to the stream
* @throws java.io.IOException if the stream throws an exception
*/
public abstract int pipe( OutputStream out )
throws IOException;
/**
* Gets a copy of the buffered bytes.
*
* @return the byte array
* @see org.bson.io.OutputBuffer#pipe(java.io.OutputStream)
*/
public byte [] toByteArray(){
try {
final ByteArrayOutputStream bout = new ByteArrayOutputStream( size() );
pipe( bout );
return bout.toByteArray();
}
catch ( IOException ioe ){
throw new RuntimeException( "should be impossible" , ioe );
}
}
/**
* @deprecated This method is NOT a part of public API and will be dropped in 3.x versions.
* @return the underlying byte array as a string
*/
@Deprecated
public String asString(){
return new String( toByteArray() );
}
/**
* @deprecated This method is NOT a part of public API and will be dropped in 3.x versions.
*/
@Deprecated
public String asString( String encoding )
throws UnsupportedEncodingException {
return new String( toByteArray() , encoding );
}
/**
* @deprecated This method is NOT a part of public API and will be dropped in 3.x versions.
*/
@Deprecated
public String hex(){
final StringBuilder buf = new StringBuilder();
try {
pipe( new OutputStream(){
public void write( int b ){
String s = Integer.toHexString(0xff & b);
if (s.length() < 2)
buf.append("0");
buf.append(s);
}
}
);
}
catch ( IOException ioe ){
throw new RuntimeException( "impossible" );
}
return buf.toString();
}
/**
* @deprecated This method is NOT a part of public API and will be dropped in 3.x versions.
*/
@Deprecated
public String md5(){
final MessageDigest md5 ;
try {
md5 = MessageDigest.getInstance("MD5");
}
catch (NoSuchAlgorithmException e) {
throw new RuntimeException("Error - this implementation of Java doesn't support MD5.");
}
md5.reset();
try {
pipe( new OutputStream(){
public void write( byte[] b , int off , int len ){
md5.update( b , off , len );
}
public void write( int b ){
md5.update( (byte)(b&0xFF) );
}
}
);
}
catch ( IOException ioe ){
throw new RuntimeException( "impossible" );
}
return com.mongodb.util.Util.toHex( md5.digest() );
}
/**
* Writes the given integer value to the buffer.
*
* @param x the value to write
*/
public void writeInt( int x ){
write( x >> 0 );
write( x >> 8 );
write( x >> 16 );
write( x >> 24 );
}
/**
* @deprecated This method is NOT a part of public API and will be dropped in 3.x versions.
*/
@Deprecated
public void writeIntBE( int x ){
write( x >> 24 );
write(x >> 16);
write(x >> 8);
write(x);
}
/**
* @deprecated This method is NOT a part of public API and will be dropped in 3.x versions.
*/
@Deprecated
public void writeInt( int pos , int x ){
final int save = getPosition();
setPosition(pos);
writeInt(x);
setPosition(save);
}
/**
* Writes the given long value to the buffer.
*
* @param x the value to write
*/
public void writeLong( long x ){
write( (byte)(0xFFL & ( x >> 0 ) ) );
write( (byte)(0xFFL & ( x >> 8 ) ) );
write( (byte)(0xFFL & ( x >> 16 ) ) );
write( (byte)(0xFFL & ( x >> 24 ) ) );
write( (byte)(0xFFL & ( x >> 32 ) ) );
write( (byte)(0xFFL & ( x >> 40 ) ) );
write( (byte)(0xFFL & ( x >> 48 ) ) );
write((byte) (0xFFL & (x >> 56)));
}
/**
* Writes a BSON double to the stream.
*
* @param x the value
*/
public void writeDouble( double x ){
writeLong(Double.doubleToRawLongBits(x));
}
/**
* Writes a BSON String to the stream.
*
* @param str the value
*/
public void writeString(final String str) {
writeInt(0); // making space for size
final int strLen = writeCString(str, false);
backpatchSize(strLen, 4);
}
/**
* Writes C string (null-terminated string) to underlying buffer.
*
* @param str the string
* @return number of bytes written
*/
public int writeCString(final String str) {
return writeCString(str, true);
}
private int writeCString(final String str, final boolean checkForNullCharacters) {
final int len = str.length();
int total = 0;
for (int i = 0; i < len;/*i gets incremented*/) {
final int c = Character.codePointAt(str, i);
if (checkForNullCharacters && c == 0x0) {
throw new BSONException(
String.format("BSON cstring '%s' is not valid because it contains a null character at index %d", str, i));
}
if (c < 0x80) {
write((byte) c);
total += 1;
} else if (c < 0x800) {
write((byte) (0xc0 + (c >> 6)));
write((byte) (0x80 + (c & 0x3f)));
total += 2;
} else if (c < 0x10000) {
write((byte) (0xe0 + (c >> 12)));
write((byte) (0x80 + ((c >> 6) & 0x3f)));
write((byte) (0x80 + (c & 0x3f)));
total += 3;
} else {
write((byte) (0xf0 + (c >> 18)));
write((byte) (0x80 + ((c >> 12) & 0x3f)));
write((byte) (0x80 + ((c >> 6) & 0x3f)));
write((byte) (0x80 + (c & 0x3f)));
total += 4;
}
i += Character.charCount(c);
}
write((byte) 0);
total++;
return total;
}
@Override
public String toString(){
return getClass().getName() + " size: " + size() + " pos: " + getPosition() ;
}
/**
* Backpatches the size of a document or string by writing the size into the four bytes starting at getPosition() -
* size.
*
* @param size the size of the document/string
*/
public void backpatchSize(final int size) {
writeInt(getPosition() - size, size);
}
/**
* Backpatches the size of a document or string by writing the size into the four bytes starting at {@code getPosition() - size -
* additionalOffset}.
*
* @param size the size of the document/string
* @param additionalOffset the offset from the current position to write the size
*/
protected void backpatchSize(final int size, final int additionalOffset) {
writeInt(getPosition() - size - additionalOffset, size);
}
/**
* Truncates the buffer to the given new position, which must be greater than or equal to zero and less than or equal to the current
* size of this buffer.
*
* @param newPosition the position to truncate this buffer to
*/
public void truncateToPosition(int newPosition) {
setPosition(newPosition);
}
}