host.anzo.commons.io.binary.BufferedRandomAccessFile Maven / Gradle / Ivy
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package host.anzo.commons.io.binary;
import lombok.Getter;
import org.jetbrains.annotations.Nullable;
import java.io.*;
import java.nio.channels.WritableByteChannel;
import java.util.*;
/**
* A buffered drop-in replacement for java.io.RandomAccessFile.
* Instances of this class realise substantial speed increases over
* java.io.RandomAccessFile through the use of buffering. This is a
* subclass of Object, as it was not possible to subclass
* java.io.RandomAccessFile because many of the methods are
* final. However, if it is necessary to use RandomAccessFile and
* java.io.RandomAccessFile interchangeably, both classes implement the
* DataInput and DataOutput interfaces.
*
*
By Russ Rew, based on
* BufferedRandomAccessFile by Alex McManus, based on Sun's source code
* for java.io.RandomAccessFile. For Alex McManus version from which
* this derives, see his
* Freeware Java Classes.
*
*
* @author Alex McManus
* @author Russ Rew
* @author john caron
* @see DataInput
* @see DataOutput
* @see java.io.RandomAccessFile
*/
public class BufferedRandomAccessFile implements DataInput, DataOutput {
static public final int BIG_ENDIAN = 0;
static public final int LITTLE_ENDIAN = 1;
static protected Set allFiles = new HashSet<>();
/**
* List of open files.
* Debugging, don't use.
*/
static protected @Getter List openFiles = Collections.synchronizedList(new ArrayList<>());
static public @Nullable List getAllFiles() {
if (null == allFiles) {
return null;
}
List result = new ArrayList<>(allFiles);
Collections.sort(result);
return result;
}
static protected boolean showOpen = false;
static protected boolean showRead = false;
/**
* The default buffer size, in bytes.
*/
protected static final int defaultBufferSize = 8092;
/////////////////////////////////////////////////////////////////////////////////////////////
/**
* File location
*/
protected String location;
/**
* The underlying java.io.RandomAccessFile.
*/
protected java.io.RandomAccessFile file;
protected java.nio.channels.FileChannel fileChannel;
/**
* The offset in bytes from the file start, of the next read or
* write operation.
*/
protected long filePosition;
/**
* The buffer used for reading the data.
*/
protected byte[] buffer;
/**
* The offset in bytes of the start of the buffer, from the start of the file.
*/
protected long bufferStart;
/**
* The offset in bytes of the end of the data in the buffer, from
* the start of the file. This can be calculated from
* bufferStart + dataSize, but it is cached to speed
* up the read( ) method.
*/
protected long dataEnd;
/**
* The size of the data stored in the buffer, in bytes. This may be
* less than the size of the buffer.
*/
protected int dataSize;
/**
* True if we are at the end of the file.
*/
protected boolean endOfFile;
/**
* The access mode of the file.
*/
protected boolean readonly;
/**
* The current endian (big or little) mode of the file.
*/
protected boolean bigEndian;
/**
* True if the data in the buffer has been modified.
*/
boolean bufferModified = false;
/**
* make sure file is this long when closed
*/
private long minLength = 0;
/**
* stupid extendMode for truncated, yet valid files - old code allowed NOFILL to do this
*/
boolean extendMode = false;
/**
* Constructor, for subclasses
*
* @param bufferSize size of read buffer
*/
protected BufferedRandomAccessFile(int bufferSize) {
file = null;
readonly = true;
init(bufferSize);
}
/**
* Constructor, default buffer size.
*
* @param location location of the file
* @param mode same as for java.io.RandomAccessFile
* @throws IOException on open error
*/
public BufferedRandomAccessFile(String location, String mode) throws IOException {
this(location, mode, defaultBufferSize);
this.location = location;
}
/**
* Constructor.
*
* @param location location of the file
* @param mode same as for java.io.RandomAccessFile
* @param bufferSize size of buffer to use.
* @throws IOException on open error
*/
public BufferedRandomAccessFile(String location, String mode, int bufferSize) throws IOException {
this.location = location;
this.file = new java.io.RandomAccessFile(location, mode);
this.readonly = mode.equals("r");
init(bufferSize);
}
/**
* Allow access to the underlying java.io.RandomAccessFile.
* WARNING! BROKEN ENCAPSOLATION, DO NOT USE. May change implementation in the future.
*
* @return the underlying java.io.RandomAccessFile.
*/
public java.io.RandomAccessFile getRandomAccessFile() {
return this.file;
}
private void init(int bufferSize) {
// Initialise the buffer
bufferStart = 0;
dataEnd = 0;
dataSize = 0;
filePosition = 0;
buffer = new byte[bufferSize];
endOfFile = false;
}
/**
* Set the buffer size.
* If writing, call flush() first.
*
* @param bufferSize length in bytes
*/
public void setBufferSize(int bufferSize) {
init(bufferSize);
}
/**
* Get the buffer size
*
* @return bufferSize length in bytes
*/
public int getBufferSize() {
return buffer.length;
}
/**
* Close the file, and release any associated system resources.
*
* @throws IOException if an I/O error occurrs.
*/
public void close() throws IOException {
if (file == null)
return;
// If we are writing and the buffer has been modified, flush the contents
// of the buffer.
flush();
/*
if (!readonly && bufferModified) {
file.seek(bufferStart);
file.write(buffer, 0, dataSize);
} */
// may need to extend file, in case no fill is being used
// may need to truncate file in case overwriting a longer file
// use only if minLength is set (by N3iosp)
long fileSize = file.length();
if (!readonly && (minLength != 0) && (minLength != fileSize)) {
file.setLength(minLength);
// System.out.println("TRUNCATE!!! minlength="+minLength);
}
// Close the underlying file object.
file.close();
file = null; // help the gc
}
/**
* Return true if file pointer is at end of file.
*
* @return true if file pointer is at end of file
*/
public boolean isAtEndOfFile() {
return endOfFile;
}
/**
* Set the position in the file for the next read or write.
*
* @param pos the offset (in bytes) from the start of the file.
* @throws IOException if an I/O error occurrs.
*/
public void seek(long pos) throws IOException {
// If the seek is into the buffer, just update the file pointer.
if ((pos >= bufferStart) && (pos < dataEnd)) {
filePosition = pos;
return;
}
// need new buffer, starting at pos
readBuffer(pos);
}
protected void readBuffer(long pos) throws IOException {
// If the current buffer is modified, write it to disk.
if (bufferModified) {
flush();
}
bufferStart = pos;
filePosition = pos;
dataSize = read_(pos, buffer, 0, buffer.length);
if (dataSize <= 0) {
dataSize = 0;
endOfFile = true;
} else {
endOfFile = false;
}
// Cache the position of the buffer end.
dataEnd = bufferStart + dataSize;
}
/**
* Returns the current position in the file, where the next read or
* write will occur.
*
* @return the offset from the start of the file in bytes.
* @throws IOException if an I/O error occurrs.
*/
public long getFilePointer() throws IOException {
return filePosition;
}
/**
* Get the file location, or name.
*
* @return file location
*/
public String getLocation() {
return location;
}
/**
* Get the length of the file. The data in the buffer (which may not
* have been written the disk yet) is taken into account.
*
* @return the length of the file in bytes.
* @throws IOException if an I/O error occurrs.
*/
public long length() throws IOException {
long fileLength = file.length();
return Math.max(fileLength, dataEnd);
}
/**
* Change the current endian mode. Subsequent reads of short, int, float, double, long, char will
* use this. Does not currently affect writes.
* Default values is BIG_ENDIAN.
*
* @param endian RandomAccessFile.BIG_ENDIAN or RandomAccessFile.LITTLE_ENDIAN
*/
public void order(int endian) {
if (endian < 0) return;
this.bigEndian = (endian == BIG_ENDIAN);
}
/**
* Returns the opaque file descriptor object associated with this file.
*
* @return the file descriptor object associated with this file.
* @throws IOException if an I/O error occurs.
*/
public FileDescriptor getFD() throws IOException {
return (file == null) ? null : file.getFD();
}
/**
* Copy the contents of the buffer to the disk.
*
* @throws IOException if an I/O error occurs.
*/
public void flush() throws IOException {
if (bufferModified) {
file.seek(bufferStart);
file.write(buffer, 0, dataSize);
//System.out.println("--flush at "+bufferStart+" dataSize= "+dataSize+ " filePosition= "+filePosition);
bufferModified = false;
}
/* check min length
if (!readonly && (minLength != 0) && (minLength != file.length())) {
file.setLength(minLength);
} */
}
/**
* Make sure file is at least this long when its closed.
* needed when not using fill mode, and not all data is written.
*
* @param minLength minimum length of the file.
*/
public void setMinLength(long minLength) {
this.minLength = minLength;
}
/**
* Set extendMode for truncated, yet valid files - old NetCDF code allowed this
* when NOFILL on, and user doesnt write all variables.
*/
public void setExtendMode() {
this.extendMode = true;
}
//////////////////////////////////////////////////////////////////////////////////////////////
// Read primitives.
//
/**
* Read a byte of data from the file, blocking until data is
* available.
*
* @return the next byte of data, or -1 if the end of the file is
* reached.
* @throws IOException if an I/O error occurrs.
*/
public int read() throws IOException {
// If the file position is within the data, return the byte...
if (filePosition < dataEnd) {
int pos = (int) (filePosition - bufferStart);
filePosition++;
return (buffer[pos] & 0xff);
// ...or should we indicate EOF...
} else if (endOfFile) {
return -1;
// ...or seek to fill the buffer, and try again.
} else {
seek(filePosition);
return read();
}
}
/**
* Read up to len bytes into an array, at a specified
* offset. This will block until at least one byte has been read.
*
* @param b the byte array to receive the bytes.
* @param off the offset in the array where copying will start.
* @param len the number of bytes to copy.
* @return the actual number of bytes read, or -1 if there is not
* more data due to the end of the file being reached.
* @throws IOException if an I/O error occurrs.
*/
protected int readBytes(byte b[], int off, int len) throws IOException {
// Check for end of file.
if (endOfFile) {
return -1;
}
// See how many bytes are available in the buffer - if none,
// seek to the file position to update the buffer and try again.
int bytesAvailable = (int) (dataEnd - filePosition);
if (bytesAvailable < 1) {
seek(filePosition);
return readBytes(b, off, len);
}
// Copy as much as we can.
int copyLength = Math.min(bytesAvailable, len);
System.arraycopy(buffer, (int) (filePosition - bufferStart), b, off, copyLength);
filePosition += copyLength;
// If there is more to copy...
if (copyLength < len) {
int extraCopy = len - copyLength;
// If the amount remaining is more than a buffer's length, read it
// directly from the file.
if (extraCopy > buffer.length) {
extraCopy = read_(filePosition, b, off + copyLength, len - copyLength);
// ...or read a new buffer full, and copy as much as possible...
} else {
seek(filePosition);
if (!endOfFile) {
extraCopy = Math.min(extraCopy, dataSize);
System.arraycopy(buffer, 0, b, off + copyLength, extraCopy);
} else {
extraCopy = -1;
}
}
// If we did manage to copy any more, update the file position and
// return the amount copied.
if (extraCopy > 0) {
filePosition += extraCopy;
return copyLength + extraCopy;
}
}
// Return the amount copied.
return copyLength;
}
/**
* Read nbytes bytes, at the specified file offset, send to a WritableByteChannel.
* This will block until all bytes are read.
* This uses the underlying file channel directly, bypassing all user buffers.
*
* @param dest write to this WritableByteChannel.
* @param offset the offset in the file where copying will start.
* @param nbytes the number of bytes to read.
* @return the actual number of bytes read and transfered
* @throws IOException if an I/O error occurs.
*/
public long readToByteChannel(WritableByteChannel dest, long offset, long nbytes) throws IOException {
if (fileChannel == null)
fileChannel = file.getChannel();
long need = nbytes;
while (need > 0) {
long count = fileChannel.transferTo(offset, need, dest);
//if (count == 0) break; // LOOK not sure what the EOF condition is
need -= count;
offset += count;
}
return nbytes - need;
}
/**
* Read directly from file, without going through the buffer.
* All reading goes through here or readToByteChannel;
*
* @param pos start here in the file
* @param b put data into this buffer
* @param offset buffer offset
* @param len this number of bytes
* @return actual number of bytes read
* @throws IOException on io error
*/
protected int read_(long pos, byte[] b, int offset, int len) throws IOException {
file.seek(pos);
int n = file.read(b, offset, len);
if (extendMode && (n < len)) {
//System.out.println(" read_ = "+len+" at "+pos+"; got = "+n);
n = len;
}
return n;
}
/**
* Read up to len bytes into an array, at a specified
* offset. This will block until at least one byte has been read.
*
* @param b the byte array to receive the bytes.
* @param off the offset in the array where copying will start.
* @param len the number of bytes to copy.
* @return the actual number of bytes read, or -1 if there is not
* more data due to the end of the file being reached.
* @throws IOException if an I/O error occurrs.
*/
public int read(byte b[], int off, int len) throws IOException {
return readBytes(b, off, len);
}
/**
* Read up to b.length( ) bytes into an array. This
* will block until at least one byte has been read.
*
* @param b the byte array to receive the bytes.
* @return the actual number of bytes read, or -1 if there is not
* more data due to the end of the file being reached.
* @throws IOException if an I/O error occurrs.
*/
public int read(byte b[]) throws IOException {
return readBytes(b, 0, b.length);
}
/**
* Read fully count number of bytes
*
* @param count how many bytes tp read
* @return a byte array of length count, fully read in
* @throws IOException if an I/O error occurrs.
*/
public byte[] readBytes(int count) throws IOException {
byte[] b = new byte[count];
readFully(b);
return b;
}
/**
* Reads b.length bytes from this file into the byte
* array. This method reads repeatedly from the file until all the
* bytes are read. This method blocks until all the bytes are read,
* the end of the stream is detected, or an exception is thrown.
*
* @param b the buffer into which the data is read.
* @throws EOFException if this file reaches the end before reading
* all the bytes.
* @throws IOException if an I/O error occurs.
*/
public final void readFully(byte[] b) throws IOException {
readFully(b, 0, b.length);
}
/**
* Reads exactly len bytes from this file into the byte
* array. This method reads repeatedly from the file until all the
* bytes are read. This method blocks until all the bytes are read,
* the end of the stream is detected, or an exception is thrown.
*
* @param b the buffer into which the data is read.
* @param off the start offset of the data.
* @param len the number of bytes to read.
* @throws EOFException if this file reaches the end before reading
* all the bytes.
* @throws IOException if an I/O error occurs.
*/
public final void readFully(byte b[], int off, int len) throws IOException {
int n = 0;
while (n < len) {
int count = this.read(b, off + n, len - n);
if (count < 0) {
throw new EOFException();
}
n += count;
}
}
/**
* Skips exactly n bytes of input.
* This method blocks until all the bytes are skipped, the end of
* the stream is detected, or an exception is thrown.
*
* @param n the number of bytes to be skipped.
* @return the number of bytes skipped, which is always n.
* @throws EOFException if this file reaches the end before skipping
* all the bytes.
* @throws IOException if an I/O error occurs.
*/
public int skipBytes(int n) throws IOException {
seek(getFilePointer() + n);
return n;
}
/* public void skipToMultiple( int multipleOfBytes) throws IOException {
long pos = getFilePointer();
int pad = (int) (pos % multipleOfBytes);
if (pad != 0) pad = multipleOfBytes - pad;
if (pad > 0) skipBytes(pad);
} */
/**
* Unread the last byte read.
* This method should not be used more than once
* between reading operations, or strange things might happen.
*/
public void unread() {
filePosition--;
}
//
// Write primitives.
//
/**
* Write a byte to the file. If the file has not been opened for
* writing, an IOException will be raised only when an attempt is
* made to write the buffer to the file.
*
* Caveat: the effects of seek( )ing beyond the end of the file are
* undefined.
*
* @param b write this byte
* @throws IOException if an I/O error occurrs.
*/
public void write(int b) throws IOException {
// If the file position is within the block of data...
if (filePosition < dataEnd) {
int pos = (int) (filePosition - bufferStart);
buffer[pos] = (byte) b;
bufferModified = true;
filePosition++;
// ...or (assuming that seek will not allow the file pointer
// to move beyond the end of the file) get the correct block of
// data...
} else {
// If there is room in the buffer, expand it...
if (dataSize != buffer.length) {
int pos = (int) (filePosition - bufferStart);
buffer[pos] = (byte) b;
bufferModified = true;
filePosition++;
dataSize++;
dataEnd++;
// ...or do another seek to get a new buffer, and start again...
} else {
seek(filePosition);
write(b);
}
}
}
/**
* Write len bytes from an array to the file.
*
* @param b the array containing the data.
* @param off the offset in the array to the data.
* @param len the length of the data.
* @throws IOException if an I/O error occurrs.
*/
public void writeBytes(byte b[], int off, int len) throws IOException {
// If the amount of data is small (less than a full buffer)...
if (len < buffer.length) {
// If any of the data fits within the buffer...
int spaceInBuffer = 0;
int copyLength = 0;
if (filePosition >= bufferStart) {
spaceInBuffer = (int) ((bufferStart + buffer.length) - filePosition);
}
if (spaceInBuffer > 0) {
// Copy as much as possible to the buffer.
copyLength = Math.min(spaceInBuffer, len);
System.arraycopy(b, off, buffer, (int) (filePosition - bufferStart), copyLength);
bufferModified = true;
long myDataEnd = filePosition + copyLength;
dataEnd = Math.max(myDataEnd, dataEnd);
dataSize = (int) (dataEnd - bufferStart);
filePosition += copyLength;
///System.out.println("--copy to buffer "+copyLength+" "+len);
}
// If there is any data remaining, move to the new position and copy to
// the new buffer.
if (copyLength < len) {
//System.out.println("--need more "+copyLength+" "+len+" space= "+spaceInBuffer);
seek(filePosition); // triggers a flush
System.arraycopy(b, off + copyLength, buffer, (int) (filePosition - bufferStart), len - copyLength);
bufferModified = true;
long myDataEnd = filePosition + (len - copyLength);
dataEnd = Math.max(myDataEnd, dataEnd);
dataSize = (int) (dataEnd - bufferStart);
filePosition += (len - copyLength);
}
// ...or write a lot of data...
} else {
// Flush the current buffer, and write this data to the file.
if (bufferModified) {
flush();
}
file.seek(filePosition); // moved per Steve Cerruti; Jan 14, 2005
file.write(b, off, len);
//System.out.println("--write at "+filePosition+" "+len);
filePosition += len;
bufferStart = filePosition; // an empty buffer
dataSize = 0;
dataEnd = bufferStart + dataSize;
}
}
/**
* Writes b.length bytes from the specified byte array
* starting at offset off to this file.
*
* @param b the data.
* @throws IOException if an I/O error occurs.
*/
public void write(byte b[]) throws IOException {
writeBytes(b, 0, b.length);
}
/**
* Writes len bytes from the specified byte array
* starting at offset off to this file.
*
* @param b the data.
* @param off the start offset in the data.
* @param len the number of bytes to write.
* @throws IOException if an I/O error occurs.
*/
public void write(byte b[], int off, int len) throws IOException {
writeBytes(b, off, len);
}
//
// DataInput methods.
//
/**
* Reads a boolean from this file. This method reads a
* single byte from the file. A value of 0 represents
* false. Any other value represents true.
* This method blocks until the byte is read, the end of the stream
* is detected, or an exception is thrown.
*
* @return the boolean value read.
* @throws EOFException if this file has reached the end.
* @throws IOException if an I/O error occurs.
*/
public final boolean readBoolean() throws IOException {
int ch = this.read();
if (ch < 0) {
throw new EOFException();
}
return (ch != 0);
}
/**
* Reads a signed 8-bit value from this file. This method reads a
* byte from the file. If the byte read is b, where
* 0 <= b <= 255,
* then the result is: (byte)(b)
*
* This method blocks until the byte is read, the end of the stream
* is detected, or an exception is thrown.
*
* @return the next byte of this file as a signed 8-bit
* byte.
* @throws EOFException if this file has reached the end.
* @throws IOException if an I/O error occurs.
*/
public final byte readByte() throws IOException {
int ch = this.read();
if (ch < 0) {
throw new EOFException();
}
return (byte) (ch);
}
/**
* Reads an unsigned 8-bit number from this file. This method reads
* a byte from this file and returns that byte.
*
* This method blocks until the byte is read, the end of the stream
* is detected, or an exception is thrown.
*
* @return the next byte of this file, interpreted as an unsigned
* 8-bit number.
* @throws EOFException if this file has reached the end.
* @throws IOException if an I/O error occurs.
*/
public final int readUnsignedByte() throws IOException {
int ch = this.read();
if (ch < 0) {
throw new EOFException();
}
return ch;
}
/**
* Reads a signed 16-bit number from this file. The method reads 2
* bytes from this file. If the two bytes read, in order, are
* b1 and b2, where each of the two values is
* between 0 and 255, inclusive, then the
* result is equal to: (short)((b1 << 8) | b2)
*
* This method blocks until the two bytes are read, the end of the
* stream is detected, or an exception is thrown.
*
* @return the next two bytes of this file, interpreted as a signed
* 16-bit number.
* @throws EOFException if this file reaches the end before reading
* two bytes.
* @throws IOException if an I/O error occurs.
*/
public final short readShort() throws IOException {
int ch1 = this.read();
int ch2 = this.read();
if ((ch1 | ch2) < 0) {
throw new EOFException();
}
if (bigEndian) {
return (short) ((ch1 << 8) + (ch2));
} else {
return (short) ((ch2 << 8) + (ch1));
}
}
/**
* Read an array of shorts
*
* @param pa read into this array
* @param start starting at pa[start]
* @param n read this many elements
* @throws IOException on read error
*/
public final void readShort(short[] pa, int start, int n) throws IOException {
for (int i = 0; i < n; i++) {
pa[start + i] = readShort();
}
}
/**
* Reads an unsigned 16-bit number from this file. This method reads
* two bytes from the file. If the bytes read, in order, are
* b1 and b2, where
* 0 <= b1, b2 <= 255,
* then the result is equal to: (b1 << 8) | b2
*
* This method blocks until the two bytes are read, the end of the
* stream is detected, or an exception is thrown.
*
* @return the next two bytes of this file, interpreted as an unsigned
* 16-bit integer.
* @throws EOFException if this file reaches the end before reading
* two bytes.
* @throws IOException if an I/O error occurs.
*/
public final int readUnsignedShort() throws IOException {
int ch1 = this.read();
int ch2 = this.read();
if ((ch1 | ch2) < 0) {
throw new EOFException();
}
if (bigEndian) {
return ((ch1 << 8) + (ch2));
} else {
return ((ch2 << 8) + (ch1));
}
}
/*
* Reads a signed 24-bit integer from this file. This method reads 3
* bytes from the file. If the bytes read, in order, are b1,
* b2, and b3, where
* 0 <= b1, b2, b3 <= 255,
* then the result is equal to:
*
* (b1 << 16) | (b2 << 8) + (b3 << 0)
*
*
* This method blocks until the three bytes are read, the end of the
* stream is detected, or an exception is thrown.
*/
/**
* Reads a Unicode character from this file. This method reads two
* bytes from the file. If the bytes read, in order, are
* b1 and b2, where
* 0 <= b1, b2 <= 255,
* then the result is equal to: (char)((b1 << 8) | b2)
*
* This method blocks until the two bytes are read, the end of the
* stream is detected, or an exception is thrown.
*
* @return the next two bytes of this file as a Unicode character.
* @throws EOFException if this file reaches the end before reading
* two bytes.
* @throws IOException if an I/O error occurs.
*/
public final char readChar() throws IOException {
int ch1 = this.read();
int ch2 = this.read();
if ((ch1 | ch2) < 0) {
throw new EOFException();
}
if (bigEndian) {
return (char) ((ch1 << 8) + (ch2));
} else {
return (char) ((ch2 << 8) + (ch1));
}
}
/**
* Reads a signed 32-bit integer from this file. This method reads 4
* bytes from the file. If the bytes read, in order, are b1,
* b2, b3, and b4, where
* 0 <= b1, b2, b3, b4 <= 255,
* then the result is equal to: (b1 << 24) | (b2 << 16) + (b3 << 8) + b4
*
* This method blocks until the four bytes are read, the end of the
* stream is detected, or an exception is thrown.
*
* @return the next four bytes of this file, interpreted as an
* int.
* @throws EOFException if this file reaches the end before reading
* four bytes.
* @throws IOException if an I/O error occurs.
*/
public final int readInt() throws IOException {
int ch1 = this.read();
int ch2 = this.read();
int ch3 = this.read();
int ch4 = this.read();
if ((ch1 | ch2 | ch3 | ch4) < 0) {
throw new EOFException();
}
if (bigEndian) {
return ((ch1 << 24) + (ch2 << 16) + (ch3 << 8) + (ch4));
} else {
return ((ch4 << 24) + (ch3 << 16) + (ch2 << 8) + (ch1));
}
}
/**
* Read an integer at the given position, bypassing all buffering.
*
* @param pos read a byte at this position
* @return The int that was read
* @throws IOException if an I/O error occurs.
*/
public final int readIntUnbuffered(long pos) throws IOException {
byte[] bb = new byte[4];
read_(pos, bb, 0, 4);
int ch1 = bb[0] & 0xff;
int ch2 = bb[1] & 0xff;
int ch3 = bb[2] & 0xff;
int ch4 = bb[3] & 0xff;
if ((ch1 | ch2 | ch3 | ch4) < 0) {
throw new EOFException();
}
if (bigEndian) {
return ((ch1 << 24) + (ch2 << 16) + (ch3 << 8) + (ch4));
} else {
return ((ch4 << 24) + (ch3 << 16) + (ch2 << 8) + (ch1));
}
}
/**
* Read an array of ints
*
* @param pa read into this array
* @param start starting at pa[start]
* @param n read this many elements
* @throws IOException on read error
*/
public final void readInt(int[] pa, int start, int n) throws IOException {
for (int i = 0; i < n; i++) {
pa[start + i] = readInt();
}
}
/**
* Reads a signed 64-bit integer from this file. This method reads eight
* bytes from the file. If the bytes read, in order, are
* b1, b2, b3,
* b4, b5, b6,
* b7, and b8, where: 0 <= b1, b2, b3, b4, b5, b6, b7, b8 <=255,
*
* then the result is equal to:
*
* ((long)b1 << 56) + ((long)b2 << 48)
* + ((long)b3 << 40) + ((long)b4 << 32)
* + ((long)b5 << 24) + ((long)b6 << 16)
* + ((long)b7 << 8) + b8
*
*
* This method blocks until the eight bytes are read, the end of the
* stream is detected, or an exception is thrown.
*
* @return the next eight bytes of this file, interpreted as a
* long.
* @throws EOFException if this file reaches the end before reading
* eight bytes.
* @throws IOException if an I/O error occurs.
*/
public final long readLong() throws IOException {
if (bigEndian) {
return ((long) (readInt()) << 32) + (readInt() & 0xFFFFFFFFL); // tested ok
} else {
return ((readInt() & 0xFFFFFFFFL) + ((long) readInt() << 32)); // not tested yet ??
}
/* int ch1 = this.read();
int ch2 = this.read();
int ch3 = this.read();
int ch4 = this.read();
int ch5 = this.read();
int ch6 = this.read();
int ch7 = this.read();
int ch8 = this.read();
if ((ch1 | ch2 | ch3 | ch4 | ch5 | ch6 | ch7 | ch8) < 0)
throw new EOFException();
if (bigEndian)
return ((long)(ch1 << 56)) + (ch2 << 48) + (ch3 << 40) + (ch4 << 32) + (ch5 << 24) + (ch6 << 16) + (ch7 << 8) + (ch8 << 0));
else
return ((long)(ch8 << 56) + (ch7 << 48) + (ch6 << 40) + (ch5 << 32) + (ch4 << 24) + (ch3 << 16) + (ch2 << 8) + (ch1 << 0));
*/
}
/**
* Read an array of longs
*
* @param pa read into this array
* @param start starting at pa[start]
* @param n read this many elements
* @throws IOException on read error
*/
public final void readLong(long[] pa, int start, int n) throws IOException {
for (int i = 0; i < n; i++) {
pa[start + i] = readLong();
}
}
/**
* Reads a float from this file. This method reads an
* int value as if by the readInt method
* and then converts that int to a float
* using the intBitsToFloat method in class
* Float.
*
* This method blocks until the four bytes are read, the end of the
* stream is detected, or an exception is thrown.
*
* @return the next four bytes of this file, interpreted as a
* float.
* @throws EOFException if this file reaches the end before reading
* four bytes.
* @throws IOException if an I/O error occurs.
* @see java.io.RandomAccessFile#readInt()
* @see Float#intBitsToFloat(int)
*/
public final float readFloat() throws IOException {
return Float.intBitsToFloat(readInt());
}
/**
* Read an array of floats
*
* @param pa read into this array
* @param start starting at pa[start]
* @param n read this many elements
* @throws IOException on read error
*/
public final void readFloat(float[] pa, int start, int n) throws IOException {
for (int i = 0; i < n; i++) {
pa[start + i] = Float.intBitsToFloat(readInt());
}
}
/**
* Reads a double from this file. This method reads a
* long value as if by the readLong method
* and then converts that long to a double
* using the longBitsToDouble method in
* class Double.
*
* This method blocks until the eight bytes are read, the end of the
* stream is detected, or an exception is thrown.
*
* @return the next eight bytes of this file, interpreted as a
* double.
* @throws EOFException if this file reaches the end before reading
* eight bytes.
* @throws IOException if an I/O error occurs.
* @see java.io.RandomAccessFile#readLong()
* @see Double#longBitsToDouble(long)
*/
public final double readDouble() throws IOException {
return Double.longBitsToDouble(readLong());
}
/**
* Read an array of doubles
*
* @param pa read into this array
* @param start starting at pa[start]
* @param n read this many elements
* @throws IOException on read error
*/
public final void readDouble(double[] pa, int start, int n) throws IOException {
for (int i = 0; i < n; i++) {
pa[start + i] = Double.longBitsToDouble(readLong());
}
}
/**
* Reads the next line of text from this file. This method
* successively reads bytes from the file until it reaches the end of
* a line of text.
*
*
* A line of text is terminated by a carriage-return character
* ('\r'), a newline character ('\n'), a
* carriage-return character immediately followed by a newline
* character, or the end of the input stream. The line-terminating
* character(s), if any, are included as part of the string returned.
*
*
* This method blocks until a newline character is read, a carriage
* return and the byte following it are read (to see if it is a
* newline), the end of the stream is detected, or an exception is thrown.
*
* @return the next line of text from this file.
* @throws IOException if an I/O error occurs.
*/
public final String readLine() throws IOException {
StringBuilder input = new StringBuilder();
int c;
while (((c = read()) != -1) && (c != '\n')) {
input.append((char) c);
}
if ((c == -1) && (input.isEmpty())) {
return null;
}
return input.toString();
}
/**
* Reads in a string from this file. The string has been encoded
* using a modified UTF-8 format.
*
* The first two bytes are read as if by
* readUnsignedShort. This value gives the number of
* following bytes that are in the encoded string, not
* the length of the resulting string. The following bytes are then
* interpreted as bytes encoding characters in the UTF-8 format
* and are converted into characters.
*
* This method blocks until all the bytes are read, the end of the
* stream is detected, or an exception is thrown.
*
* @return a Unicode string.
* @throws EOFException if this file reaches the end before
* reading all the bytes.
* @throws IOException if an I/O error occurs.
* @throws UTFDataFormatException if the bytes do not represent
* valid UTF-8 encoding of a Unicode string.
* @see java.io.RandomAccessFile#readUnsignedShort()
*/
public final String readUTF() throws IOException {
return DataInputStream.readUTF(this);
}
/**
* Read a String of knoen length.
*
* @param nbytes number of bytes to read
* @return String wrapping the bytes.
* @throws IOException if an I/O error occurs.
*/
public String readString(int nbytes) throws IOException {
byte[] data = new byte[nbytes];
readFully(data);
return new String(data);
}
//
// DataOutput methods.
//
/**
* Writes a boolean to the file as a 1-byte value. The
* value true is written out as the value
* (byte)1; the value false is written out
* as the value (byte)0.
*
* @param v a boolean value to be written.
* @throws IOException if an I/O error occurs.
*/
public final void writeBoolean(boolean v) throws IOException {
write(v ? 1 : 0);
}
/**
* Write an array of booleans
*
* @param pa write from this array
* @param start starting with this element in the array
* @param n write this number of elements
* @throws IOException on read error
*/
public final void writeBoolean(boolean[] pa, int start, int n) throws IOException {
for (int i = 0; i < n; i++) {
writeBoolean(pa[start + i]);
}
}
/**
* Writes a byte to the file as a 1-byte value.
*
* @param v a byte value to be written.
* @throws IOException if an I/O error occurs.
*/
public final void writeByte(int v) throws IOException {
write(v);
}
/**
* Writes a short to the file as two bytes, high byte first.
*
* @param v a short to be written.
* @throws IOException if an I/O error occurs.
*/
public final void writeShort(int v) throws IOException {
write((v >>> 8) & 0xFF);
write((v) & 0xFF);
}
/**
* Write an array of shorts
*
* @param pa write from this array
* @param start starting with this element in the array
* @param n this number of elements
* @throws IOException on read error
*/
public final void writeShort(short[] pa, int start, int n) throws IOException {
for (int i = 0; i < n; i++) {
writeShort(pa[start + i]);
}
}
/**
* Writes a char to the file as a 2-byte value, high
* byte first.
*
* @param v a char value to be written.
* @throws IOException if an I/O error occurs.
*/
public final void writeChar(int v) throws IOException {
write((v >>> 8) & 0xFF);
write((v) & 0xFF);
}
/**
* Write an array of chars
*
* @param pa write from this array
* @param start starting with this element in the array
* @param n this number of elements
* @throws IOException on read error
*/
public final void writeChar(char[] pa, int start, int n) throws IOException {
for (int i = 0; i < n; i++) {
writeChar(pa[start + i]);
}
}
/**
* Writes an int to the file as four bytes, high byte first.
*
* @param v an int to be written.
* @throws IOException if an I/O error occurs.
*/
public final void writeInt(int v) throws IOException {
write((v >>> 24) & 0xFF);
write((v >>> 16) & 0xFF);
write((v >>> 8) & 0xFF);
write((v) & 0xFF);
}
/**
* Write an array of ints
*
* @param pa write from this array
* @param start starting with this element in the array
* @param n write this number of elements
* @throws IOException on read error
*/
public final void writeInt(int[] pa, int start, int n) throws IOException {
for (int i = 0; i < n; i++) {
writeInt(pa[start + i]);
}
}
/**
* Writes a long to the file as eight bytes, high byte first.
*
* @param v a long to be written.
* @throws IOException if an I/O error occurs.
*/
public final void writeLong(long v) throws IOException {
write((int) (v >>> 56) & 0xFF);
write((int) (v >>> 48) & 0xFF);
write((int) (v >>> 40) & 0xFF);
write((int) (v >>> 32) & 0xFF);
write((int) (v >>> 24) & 0xFF);
write((int) (v >>> 16) & 0xFF);
write((int) (v >>> 8) & 0xFF);
write((int) (v) & 0xFF);
}
/**
* Write an array of longs
*
* @param pa write from this array
* @param start starting with this element in the array
* @param n write this number of elements
* @throws IOException on read error
*/
public final void writeLong(long[] pa, int start, int n) throws IOException {
for (int i = 0; i < n; i++) {
writeLong(pa[start + i]);
}
}
/**
* Converts the float argument to an int using the
* floatToIntBits method in class Float,
* and then writes that int value to the file as a
* 4-byte quantity, high byte first.
*
* @param v a float value to be written.
* @throws IOException if an I/O error occurs.
* @see Float#floatToIntBits(float)
*/
public final void writeFloat(float v) throws IOException {
writeInt(Float.floatToIntBits(v));
}
/**
* Write an array of floats
*
* @param pa write from this array
* @param start starting with this element in the array
* @param n write this number of elements
* @throws IOException on read error
*/
public final void writeFloat(float[] pa, int start, int n) throws IOException {
for (int i = 0; i < n; i++) {
writeFloat(pa[start + i]);
}
}
/**
* Converts the double argument to a long using the
* doubleToLongBits method in class Double,
* and then writes that long value to the file as an
* 8-byte quantity, high byte first.
*
* @param v a double value to be written.
* @throws IOException if an I/O error occurs.
* @see Double#doubleToLongBits(double)
*/
public final void writeDouble(double v) throws IOException {
writeLong(Double.doubleToLongBits(v));
}
/**
* Write an array of doubles
*
* @param pa write from this array
* @param start starting with this element in the array
* @param n write this number of elements
* @throws IOException on read error
*/
public final void writeDouble(double[] pa, int start, int n) throws IOException {
for (int i = 0; i < n; i++) {
writeDouble(pa[start + i]);
}
}
/**
* Writes the string to the file as a sequence of bytes. Each
* character in the string is written out, in sequence, by discarding
* its high eight bits.
*
* @param s a string of bytes to be written.
* @throws IOException if an I/O error occurs.
*/
public final void writeBytes(String s) throws IOException {
int len = s.length();
for (int i = 0; i < len; i++) {
write((byte) s.charAt(i));
}
}
/**
* Writes the character array to the file as a sequence of bytes. Each
* character in the string is written out, in sequence, by discarding
* its high eight bits.
*
* @param b a character array of bytes to be written.
* @param off the index of the first character to write.
* @param len the number of characters to write.
* @throws IOException if an I/O error occurs.
*/
public final void writeBytes(char b[], int off, int len) throws IOException {
for (int i = off; i < len; i++) {
write((byte) b[i]);
}
}
/**
* Writes a string to the file as a sequence of characters. Each
* character is written to the data output stream as if by the
* writeChar method.
*
* @param s a String value to be written.
* @throws IOException if an I/O error occurs.
* @see java.io.RandomAccessFile#writeChar(int)
*/
public final void writeChars(String s) throws IOException {
int len = s.length();
for (int i = 0; i < len; i++) {
int v = s.charAt(i);
write((v >>> 8) & 0xFF);
write((v) & 0xFF);
}
}
/**
* Writes a string to the file using UTF-8 encoding in a
* machine-independent manner.
*
* First, two bytes are written to the file as if by the
* writeShort method giving the number of bytes to
* follow. This value is the number of bytes actually written out,
* not the length of the string. Following the length, each character
* of the string is output, in sequence, using the UTF-8 encoding
* for each character.
*
* @param str a string to be written.
* @throws IOException if an I/O error occurs.
*/
public final void writeUTF(String str) throws IOException {
int strlen = str.length();
int utflen = 0;
for (int i = 0; i < strlen; i++) {
int c = str.charAt(i);
if ((c >= 0x0001) && (c <= 0x007F)) {
utflen++;
} else if (c > 0x07FF) {
utflen += 3;
} else {
utflen += 2;
}
}
if (utflen > 65535) {
throw new UTFDataFormatException();
}
write((utflen >>> 8) & 0xFF);
write((utflen) & 0xFF);
for (int i = 0; i < strlen; i++) {
int c = str.charAt(i);
if ((c >= 0x0001) && (c <= 0x007F)) {
write(c);
} else if (c > 0x07FF) {
write(0xE0 | ((c >> 12) & 0x0F));
write(0x80 | ((c >> 6) & 0x3F));
write(0x80 | ((c) & 0x3F));
} else {
write(0xC0 | ((c >> 6) & 0x1F));
write(0x80 | ((c) & 0x3F));
}
}
}
/**
* Create a string representation of this object.
*
* @return a string representation of the state of the object.
*/
public String toString() {
return "fp=" + filePosition + ", bs=" + bufferStart + ", de="
+ dataEnd + ", ds=" + dataSize + ", bl=" + buffer.length
+ ", readonly=" + readonly + ", bm=" + bufferModified;
}
}