com.bumptech.glide.load.resource.bitmap
Class RecyclableBufferedInputStream

java.lang.Object
  extended by java.io.InputStream
      extended by java.io.FilterInputStream
          extended by com.bumptech.glide.load.resource.bitmap.RecyclableBufferedInputStream
All Implemented Interfaces:
Closeable

public class RecyclableBufferedInputStream
extends FilterInputStream

Wraps an existing InputStream and buffers the input. Expensive interaction with the underlying input stream is minimized, since most (smaller) requests can be satisfied by accessing the buffer alone. The drawback is that some extra space is required to hold the buffer and that copying takes place when filling that buffer, but this is usually outweighed by the performance benefits.

A typical application pattern for the class looks like this:

 BufferedInputStream buf = new BufferedInputStream(new FileInputStream("file.java"));
 


Nested Class Summary
static class RecyclableBufferedInputStream.InvalidMarkException
          An exception thrown when a mark can no longer be obeyed because the underlying buffer size is smaller than the amount of data read after the mark position.
 
Field Summary
protected  byte[] buf
          The buffer containing the current bytes read from the target InputStream.
protected  int count
          The total number of bytes inside the byte array buf.
protected  int marklimit
          The current limit, which when passed, invalidates the current mark.
protected  int markpos
          The currently marked position.
protected  int pos
          The current position within the byte array buf.
 
Fields inherited from class java.io.FilterInputStream
in
 
Constructor Summary
RecyclableBufferedInputStream(InputStream in, byte[] buffer)
           
 
Method Summary
 int available()
          Returns an estimated number of bytes that can be read or skipped without blocking for more input.
 void clearMark()
           
 void close()
          Closes this stream.
 void mark(int readlimit)
          Sets a mark position in this stream.
 boolean markSupported()
          Indicates whether BufferedInputStream supports the mark(int) and reset() methods.
 int read()
          Reads a single byte from this stream and returns it as an integer in the range from 0 to 255.
 int read(byte[] buffer, int offset, int byteCount)
          Reads at most byteCount bytes from this stream and stores them in byte array buffer starting at offset offset.
 void reset()
          Resets this stream to the last marked location.
 long skip(long byteCount)
          Skips byteCount bytes in this stream.
 
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

buf

protected volatile byte[] buf
The buffer containing the current bytes read from the target InputStream.


count

protected int count
The total number of bytes inside the byte array buf.


marklimit

protected int marklimit
The current limit, which when passed, invalidates the current mark.


markpos

protected int markpos
The currently marked position. -1 indicates no mark has been set or the mark has been invalidated.


pos

protected int pos
The current position within the byte array buf.

Constructor Detail

RecyclableBufferedInputStream

public RecyclableBufferedInputStream(InputStream in,
                                     byte[] buffer)
Method Detail

available

public int available()
              throws IOException
Returns an estimated number of bytes that can be read or skipped without blocking for more input. This method returns the number of bytes available in the buffer plus those available in the source stream, but see InputStream.available() for important caveats.

Overrides:
available in class FilterInputStream
Returns:
the estimated number of bytes available
Throws:
IOException - if this stream is closed or an error occurs

close

public void close()
           throws IOException
Closes this stream. The source stream is closed and any resources associated with it are released.

Specified by:
close in interface Closeable
Overrides:
close in class FilterInputStream
Throws:
IOException - if an error occurs while closing this stream.

mark

public void mark(int readlimit)
Sets a mark position in this stream. The parameter readlimit indicates how many bytes can be read before a mark is invalidated. Calling reset() will reposition the stream back to the marked position if readlimit has not been surpassed. The underlying buffer may be increased in size to allow readlimit number of bytes to be supported.

Overrides:
mark in class FilterInputStream
Parameters:
readlimit - the number of bytes that can be read before the mark is invalidated.
See Also:
reset()

clearMark

public void clearMark()

markSupported

public boolean markSupported()
Indicates whether BufferedInputStream supports the mark(int) and reset() methods.

Overrides:
markSupported in class FilterInputStream
Returns:
true for BufferedInputStreams.
See Also:
mark(int), reset()

read

public int read()
         throws IOException
Reads a single byte from this stream and returns it as an integer in the range from 0 to 255. Returns -1 if the end of the source string has been reached. If the internal buffer does not contain any available bytes then it is filled from the source stream and the first byte is returned.

Overrides:
read in class FilterInputStream
Returns:
the byte read or -1 if the end of the source stream has been reached.
Throws:
IOException - if this stream is closed or another IOException occurs.

read

public int read(byte[] buffer,
                int offset,
                int byteCount)
         throws IOException
Reads at most byteCount bytes from this stream and stores them in byte array buffer starting at offset offset. Returns the number of bytes actually read or -1 if no bytes were read and the end of the stream was encountered. If all the buffered bytes have been used, a mark has not been set and the requested number of bytes is larger than the receiver's buffer size, this implementation bypasses the buffer and simply places the results directly into buffer.

Overrides:
read in class FilterInputStream
Parameters:
buffer - the byte array in which to store the bytes read.
Returns:
the number of bytes actually read or -1 if end of stream.
Throws:
IndexOutOfBoundsException - if offset < 0 or byteCount < 0, or if offset + byteCount is greater than the size of buffer.
IOException - if the stream is already closed or another IOException occurs.

reset

public void reset()
           throws IOException
Resets this stream to the last marked location.

Overrides:
reset in class FilterInputStream
Throws:
IOException - if this stream is closed, no mark has been set or the mark is no longer valid because more than readlimit bytes have been read since setting the mark.
See Also:
mark(int)

skip

public long skip(long byteCount)
          throws IOException
Skips byteCount bytes in this stream. Subsequent calls to read() will not return these bytes unless reset() is used.

Overrides:
skip in class FilterInputStream
Parameters:
byteCount - the number of bytes to skip. skip(long) does nothing and returns 0 if byteCount is less than zero.
Returns:
the number of bytes actually skipped.
Throws:
IOException - if this stream is closed or another IOException occurs.