| java.lang.Object
 jj2000.j2k.util.ISRandomAccessIO
| ISRandomAccessIO | | public class ISRandomAccessIO implements RandomAccessIO(Code) | | This class implements a wrapper to turn an InputStream into a
RandomAccessIO. To provide random access the input data from the
InputStream is cached in an in-memory buffer. The in-memory buffer size can
be limited to a specified size. The data is read into the cache on a as
needed basis, blocking only when necessary.
The cache grows automatically as necessary. However, if the data length
is known prior to the creation of a ISRandomAccessIO object, it is best to
specify that as the initial in-memory buffer size. That will minimize data
copying and multiple allocation.
Multi-byte data is read in big-endian order. The in-memory buffer
storage is released when 'close()' is called. This class can only be used
for data input, not output. The wrapped InputStream is closed when all the
input data is cached or when 'close()' is called.
If an out of memory condition is encountered when growing the
in-memory buffer an IOException is thrown instead of an
OutOfMemoryError. The exception message is "Out of memory to cache input
data".
This class is intended for use as a "quick and dirty" way to give
network connectivity to RandomAccessIO based classes. It is not intended as
an efficient means of implementing network connectivity. Doing such
requires reimplementing the RandomAccessIO based classes to directly use
network connections.
This class does not use temporary files as buffers, because that would
preclude the use in unsigned applets.
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| Method Summary | |
| public void | close()
Closes this object for reading as well as the wrapped InputStream, if
not already closed. | | public void | flush()
Does nothing since this class does not implement data output. | | public int | getByteOrdering()
Returns the endianess (i.e., byte ordering) of multi-byte I/O
operations. | | public int | getPos()
Returns the current position in the stream, which is the
position from where the next byte of data would be read. | | public int | length()
Returns the length of the stream. | | public int | read()
Reads a byte of data from the stream. | | public byte | readByte()
Reads a signed byte (8 bit) from the input. | | public double | readDouble()
Reads an IEEE double precision (i.e., 64 bit) floating-point number
from the input. | | public float | readFloat()
Reads an IEEE single precision (i.e., 32 bit) floating-point number
from the input. | | public void | readFully(byte b, int off, int n)
Reads 'len' bytes of data from this file into an array of bytes. | | public int | readInt()
Reads a signed int (32 bit) from the input. | | public long | readLong()
Reads a signed long (64 bit) from the input. | | public short | readShort()
Reads a signed short (16 bit) from the input. | | public int | readUnsignedByte()
Reads an unsigned byte (8 bit) from the input. | | public long | readUnsignedInt()
Reads a unsigned int (32 bit) from the input. | | public int | readUnsignedShort()
Reads an unsigned short (16 bit) from the input. | | public void | seek(int off)
Moves the current position for the next read operation to
offset. | | public int | skipBytes(int n)
Skips 'n' bytes from the input. | | public void | write(int b)
Throws an IOException since this class does not implement data output. | | public void | writeByte(int v)
Throws an IOException since this class does not implement data output. | | public void | writeDouble(double v)
Throws an IOException since this class does not implement data output. | | public void | writeFloat(float v)
Throws an IOException since this class does not implement data output. | | public void | writeInt(int v)
Throws an IOException since this class does not implement data output. | | public void | writeLong(long v)
Throws an IOException since this class does not implement data output. | | public void | writeShort(int v)
Throws an IOException since this class does not implement data output. |
| ISRandomAccessIO | | public ISRandomAccessIO(InputStream is, int size, int inc, int maxsize)(Code) | | Creates a new RandomAccessIO wrapper for the given InputStream
'is'. The internal cache buffer will have size 'size' and will
increment by 'inc' each time it is needed. The maximum buffer size is
limited to 'maxsize'.
Parameters:
is - The input from where to get the data.
Parameters:
size - The initial size for the cache buffer, in bytes.
Parameters:
inc - The size increment for the cache buffer, in bytes.
Parameters:
maxsize - The maximum size for the cache buffer, in bytes. |
| ISRandomAccessIO | | public ISRandomAccessIO(InputStream is)(Code) | | Creates a new RandomAccessIO wrapper for the given InputStream
'is'. The internal cache buffer size and increment is to to 256 kB. The
maximum buffer size is set to Integer.MAX_VALUE (2 GB).
Parameters:
is - The input from where to get the data. |
| close | | public void close() throws IOException(Code) | | Closes this object for reading as well as the wrapped InputStream, if
not already closed. The memory used by the cache is released.
exception:
IOException - If an I/O error occurs while closing theunderlying InputStream. |
| flush | | public void flush()(Code) | | Does nothing since this class does not implement data output.
|
| getByteOrdering | | public int getByteOrdering()(Code) | | Returns the endianess (i.e., byte ordering) of multi-byte I/O
operations. Always EndianType.BIG_ENDIAN since this class implements
only big-endian.
Always EndianType.BIG_ENDIAN.
See Also: EndianType |
| getPos | | public int getPos() throws IOException(Code) | | Returns the current position in the stream, which is the
position from where the next byte of data would be read. The first
byte in the stream is in position 0.
exception:
IOException - If an I/O error occurred. |
| length | | public int length() throws IOException(Code) | | Returns the length of the stream. This will cause all the data to be
read. This method will block until all the data is read, which can be
lengthy across the network.
The length of the stream, in bytes.
exception:
IOException - If an I/O error ocurred. |
| read | | public int read() throws IOException(Code) | | Reads a byte of data from the stream.
The byte read, as an int in the range [0-255].
exception:
EOFException - If the end-of file was reached.
exception:
IOException - If an I/O error ocurred. |
| readByte | | public byte readByte() throws IOException(Code) | | Reads a signed byte (8 bit) from the input.
The next byte-aligned signed byte (8 bit) from theinput.
exception:
EOFException - If the end-of file was reached beforegetting all the necessary data.
exception:
IOException - If an I/O error ocurred. |
| readDouble | | public double readDouble() throws IOException(Code) | | Reads an IEEE double precision (i.e., 64 bit) floating-point number
from the input.
The next byte-aligned IEEE double (64 bit) from the input.
exception:
EOFException - If the end-of file was reached beforegetting all the necessary data.
exception:
IOException - If an I/O error ocurred. |
| readFloat | | public float readFloat() throws IOException(Code) | | Reads an IEEE single precision (i.e., 32 bit) floating-point number
from the input.
The next byte-aligned IEEE float (32 bit) from the input.
exception:
EOFException - If the end-of file was reached beforegetting all the necessary data.
exception:
IOException - If an I/O error ocurred. |
| readFully | | public void readFully(byte b, int off, int n) throws IOException(Code) | | Reads 'len' bytes of data from this file into an array of bytes. This
method reads repeatedly from the stream 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.
Parameters:
b - The buffer into which the data is to be read. It must be longenough.
Parameters:
off - The index in 'b' where to place the first byte read.
Parameters:
len - The number of bytes to read.
exception:
EOFException - If the end-of file was reached beforegetting all the necessary data.
exception:
IOException - If an I/O error ocurred. |
| readInt | | public int readInt() throws IOException(Code) | | Reads a signed int (32 bit) from the input.
The next byte-aligned signed int (32 bit) from theinput.
exception:
EOFException - If the end-of file was reached beforegetting all the necessary data.
exception:
IOException - If an I/O error ocurred. |
| readLong | | public long readLong() throws IOException(Code) | | Reads a signed long (64 bit) from the input.
The next byte-aligned signed long (64 bit) from theinput.
exception:
EOFException - If the end-of file was reached beforegetting all the necessary data.
exception:
IOException - If an I/O error ocurred. |
| readShort | | public short readShort() throws IOException(Code) | | Reads a signed short (16 bit) from the input.
The next byte-aligned signed short (16 bit) from theinput.
exception:
EOFException - If the end-of file was reached beforegetting all the necessary data.
exception:
IOException - If an I/O error ocurred. |
| readUnsignedByte | | public int readUnsignedByte() throws IOException(Code) | | Reads an unsigned byte (8 bit) from the input.
The next byte-aligned unsigned byte (8 bit) from theinput.
exception:
EOFException - If the end-of file was reached beforegetting all the necessary data.
exception:
IOException - If an I/O error ocurred. |
| readUnsignedInt | | public long readUnsignedInt() throws IOException(Code) | | Reads a unsigned int (32 bit) from the input.
The next byte-aligned unsigned int (32 bit) from theinput.
exception:
EOFException - If the end-of file was reached beforegetting all the necessary data.
exception:
IOException - If an I/O error ocurred. |
| readUnsignedShort | | public int readUnsignedShort() throws IOException(Code) | | Reads an unsigned short (16 bit) from the input.
The next byte-aligned unsigned short (16 bit) from theinput.
exception:
EOFException - If the end-of file was reached beforegetting all the necessary data.
exception:
IOException - If an I/O error ocurred. |
| seek | | public void seek(int off) throws IOException(Code) | | Moves the current position for the next read operation to
offset. The offset is measured from the beginning of the stream. If the
offset is set beyond the currently cached data, the missing data will
be read only when a read operation is performed. Setting
the offset beyond the end of the data will cause an EOFException only
if the data length is currently known, otherwise an IOException will
occur when a read operation is attempted at that position.
Parameters:
off - The offset where to move to.
exception:
EOFException - If seeking beyond EOF and the data length isknown.
exception:
IOException - If an I/O error ocurred. |
| skipBytes | | public int skipBytes(int n) throws IOException(Code) | | Skips 'n' bytes from the input.
Parameters:
n - The number of bytes to skip Always n.
exception:
EOFException - If the end-of file was reached beforeall the bytes could be skipped.
exception:
IOException - If an I/O error ocurred. |
| write | | public void write(int b) throws IOException(Code) | | Throws an IOException since this class does not implement data output.
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| writeByte | | public void writeByte(int v) throws IOException(Code) | | Throws an IOException since this class does not implement data output.
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| writeDouble | | public void writeDouble(double v) throws IOException(Code) | | Throws an IOException since this class does not implement data output.
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| writeFloat | | public void writeFloat(float v) throws IOException(Code) | | Throws an IOException since this class does not implement data output.
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| writeInt | | public void writeInt(int v) throws IOException(Code) | | Throws an IOException since this class does not implement data output.
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| writeLong | | public void writeLong(long v) throws IOException(Code) | | Throws an IOException since this class does not implement data output.
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| writeShort | | public void writeShort(int v) throws IOException(Code) | | Throws an IOException since this class does not implement data output.
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