|
||||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Objectjava.io.InputStream
java.io.FilterInputStream
org.apache.cassandra.io.FastBufferedInputStream
public class FastBufferedInputStream
A BufferedInputStream
adds functionality to another input
stream-namely, the ability to buffer the input and to support the
mark
and reset
methods. When the
BufferedInputStream
is created, an internal buffer array is
created. As bytes from the stream are read or skipped, the internal buffer is
refilled as necessary from the contained input stream, many bytes at a time.
The mark
operation remembers a point in the input stream and
the reset
operation causes all the bytes read since the most
recent mark
operation to be reread before new bytes are taken
from the contained input stream.
Author : Avinash Lakshman ( alakshman@facebook.com) & Prashant Malik ( pmalik@facebook.com )
Field Summary | |
---|---|
protected byte[] |
buf
The internal buffer array where the data is stored. |
protected int |
count
The index one greater than the index of the last valid byte in the buffer. |
protected int |
marklimit
The maximum read ahead allowed after a call to the mark
method before subsequent calls to the reset method fail. |
protected int |
markpos
The value of the pos field at the time the last
mark method was called. |
protected int |
pos
The current position in the buffer. |
Fields inherited from class java.io.FilterInputStream |
---|
in |
Constructor Summary | |
---|---|
FastBufferedInputStream(java.io.InputStream in)
Creates a BufferedInputStream and saves its argument, the
input stream in , for later use. |
|
FastBufferedInputStream(java.io.InputStream in,
int size)
Creates a BufferedInputStream with the specified buffer
size, and saves its argument, the input stream in , for
later use. |
Method Summary | |
---|---|
int |
available()
Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream. |
void |
close()
Closes this input stream and releases any system resources associated with the stream. |
void |
mark(int readlimit)
See the general contract of the mark method of
InputStream . |
boolean |
markSupported()
Tests if this input stream supports the mark and
reset methods. |
int |
read()
See the general contract of the read method of
InputStream . |
int |
read(byte[] b,
int off,
int len)
Reads bytes from this byte-input stream into the specified byte array, starting at the given offset. |
void |
reset()
See the general contract of the reset method of
InputStream . |
long |
skip(long n)
See the general contract of the skip method of
InputStream . |
Methods inherited from class java.io.FilterInputStream |
---|
read |
Methods inherited from class java.lang.Object |
---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Field Detail |
---|
protected volatile byte[] buf
protected int count
0
through
buf.length
; elements buf[0]
through
buf[count-1]
contain buffered input data obtained from the
underlying input stream.
protected int pos
buf
array.
This value is always in the range 0
through
count
. If it is less than count
, then
buf[pos]
is the next byte to be supplied as input; if it
is equal to count
, then the next read
or
skip
operation will require more bytes to be read from the
contained input stream.
BufferedInputStream.buf
protected int markpos
pos
field at the time the last
mark
method was called.
This value is always in the range -1
through
pos
. If there is no marked position in the input stream,
this field is -1
. If there is a marked position in the
input stream, then buf[markpos]
is the first byte to be
supplied as input after a reset
operation. If
markpos
is not -1
, then all bytes from
positions buf[markpos]
through buf[pos-1]
must remain in the buffer array (though they may be moved to another
place in the buffer array, with suitable adjustments to the values of
count
, pos
, and markpos
);
they may not be discarded unless and until the difference between
pos
and markpos
exceeds
marklimit
.
BufferedInputStream.mark(int)
,
BufferedInputStream.pos
protected int marklimit
mark
method before subsequent calls to the reset
method fail.
Whenever the difference between pos
and
markpos
exceeds marklimit
, then the mark
may be dropped by setting markpos
to -1
.
BufferedInputStream.mark(int)
,
BufferedInputStream.reset()
Constructor Detail |
---|
public FastBufferedInputStream(java.io.InputStream in)
BufferedInputStream
and saves its argument, the
input stream in
, for later use. An internal buffer array
is created and stored in buf
.
in
- the underlying input stream.public FastBufferedInputStream(java.io.InputStream in, int size)
BufferedInputStream
with the specified buffer
size, and saves its argument, the input stream in
, for
later use. An internal buffer array of length size
is
created and stored in buf
.
in
- the underlying input stream.size
- the buffer size.
java.lang.IllegalArgumentException
- if size <= 0.Method Detail |
---|
public int read() throws java.io.IOException
read
method of
InputStream
.
read
in class java.io.FilterInputStream
-1
if the end of the
stream is reached.
java.io.IOException
- if this input stream has been closed by invoking its
close()
method, or an I/O error occurs.FilterInputStream.in
public int read(byte[] b, int off, int len) throws java.io.IOException
This method implements the general contract of the corresponding
method of
the read
class. As an additional
convenience, it attempts to read as many bytes as possible by repeatedly
invoking the InputStream
read
method of the underlying stream. This
iterated read
continues until one of the following
conditions becomes true:
read
method of the underlying stream returns
-1
, indicating end-of-file, or
available
method of the underlying stream returns
zero, indicating that further input requests would block.
read
on the underlying stream returns
-1
to indicate end-of-file then this method returns
-1
. Otherwise this method returns the number of bytes
actually read.
Subclasses of this class are encouraged, but not required, to attempt to read as many bytes as possible in the same fashion.
read
in class java.io.FilterInputStream
b
- destination buffer.off
- offset at which to start storing bytes.len
- maximum number of bytes to read.
-1
if the end of the
stream has been reached.
java.io.IOException
- if this input stream has been closed by invoking its
close()
method, or an I/O error occurs.public long skip(long n) throws java.io.IOException
skip
method of
InputStream
.
skip
in class java.io.FilterInputStream
java.io.IOException
- if the stream does not support seek, or if this input
stream has been closed by invoking its close()
method, or an I/O error occurs.public int available() throws java.io.IOException
This method returns the sum of the number of bytes remaining to be read
in the buffer (count - pos
) and the result of
calling the in
.available().
available
in class java.io.FilterInputStream
java.io.IOException
- if this input stream has been closed by invoking its
close()
method, or an I/O error occurs.public void mark(int readlimit)
mark
method of
InputStream
.
mark
in class java.io.FilterInputStream
readlimit
- the maximum limit of bytes that can be read before the mark
position becomes invalid.BufferedInputStream.reset()
public void reset() throws java.io.IOException
reset
method of
InputStream
.
If markpos
is -1
(no mark has been set or
the mark has been invalidated), an IOException
is thrown.
Otherwise, pos
is set equal to markpos
.
reset
in class java.io.FilterInputStream
java.io.IOException
- if this stream has not been marked or, if the mark has
been invalidated, or the stream has been closed by
invoking its close()
method, or an I/O error
occurs.BufferedInputStream.mark(int)
public boolean markSupported()
mark
and
reset
methods. The markSupported
method of
BufferedInputStream
returns true
.
markSupported
in class java.io.FilterInputStream
boolean
indicating if this stream type supports
the mark
and reset
methods.InputStream.mark(int)
,
InputStream.reset()
public void close() throws java.io.IOException
close
in interface java.io.Closeable
close
in class java.io.FilterInputStream
java.io.IOException
- if an I/O error occurs.
|
||||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |