Class UnsynchronizedBufferedInputStream

java.lang.Object
java.io.InputStream
org.apache.commons.io.input.UnsynchronizedFilterInputStream
org.apache.commons.io.input.UnsynchronizedBufferedInputStream
All Implemented Interfaces:
Closeable, AutoCloseable

An unsynchronized version of BufferedInputStream, not thread-safe.

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.

To build an instance, use UnsynchronizedBufferedInputStream.Builder.

A typical application pattern for the class looks like this:

 UnsynchronizedBufferedInputStream s = new UnsynchronizedBufferedInputStream.Builder().
   .setInputStream(new FileInputStream("file.java"))
   .setBufferSize(8192)
   .get();
 

Provenance: Apache Harmony and modified.

Since:
2.12.0
See Also:
  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static class 
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected byte[]
    The buffer containing the current bytes read from the target InputStream.
    protected int
    The total number of bytes inside the byte array buffer.
    protected int
    The current limit, which when passed, invalidates the current mark.
    protected int
    The currently marked position. -1 indicates no mark has been set or the mark has been invalidated.
    protected int
    The current position within the byte array buffer.

    Fields inherited from class org.apache.commons.io.input.UnsynchronizedFilterInputStream

    inputStream
  • Method Summary

    Modifier and Type
    Method
    Description
    int
    Returns the number of bytes that are available before this stream will block.
    void
    Closes this stream.
    void
    mark(int readLimit)
    Sets a mark position in this stream.
    boolean
    Indicates whether BufferedInputStream supports the mark() and reset() methods.
    int
    Reads a single byte from this stream and returns it as an integer in the range from 0 to 255.
    int
    read(byte[] dest, int offset, int length)
    Reads at most length bytes from this stream and stores them in byte array buffer starting at offset offset.
    void
    Resets this stream to the last marked location.
    long
    skip(long amount)
    Skips amount number of bytes in this stream.

    Methods inherited from class org.apache.commons.io.input.UnsynchronizedFilterInputStream

    builder, read

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Field Details

    • buffer

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

      protected int count
      The total number of bytes inside the byte array buffer.
    • 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 buffer.
  • Method Details

    • available

      public int available() throws IOException
      Returns the number of bytes that are available before this stream will block. This method returns the number of bytes available in the buffer plus those available in the source stream.
      Overrides:
      available in class UnsynchronizedFilterInputStream
      Returns:
      the number of bytes available before blocking.
      Throws:
      IOException - if this stream is closed.
    • 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 AutoCloseable
      Specified by:
      close in interface Closeable
      Overrides:
      close in class UnsynchronizedFilterInputStream
      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 UnsynchronizedFilterInputStream
      Parameters:
      readLimit - the number of bytes that can be read before the mark is invalidated.
      See Also:
    • markSupported

      public boolean markSupported()
      Indicates whether BufferedInputStream supports the mark() and reset() methods.
      Overrides:
      markSupported in class UnsynchronizedFilterInputStream
      Returns:
      true for BufferedInputStreams.
      See Also:
    • 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 UnsynchronizedFilterInputStream
      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[] dest, int offset, int length) throws IOException
      Reads at most length 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 UnsynchronizedFilterInputStream
      Parameters:
      dest - the byte array in which to store the bytes read.
      offset - the initial position in buffer to store the bytes read from this stream.
      length - the maximum number of bytes to store in buffer.
      Returns:
      the number of bytes actually read or -1 if end of stream.
      Throws:
      IndexOutOfBoundsException - if offset < 0 or length < 0, or if offset + length 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 UnsynchronizedFilterInputStream
      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:
    • skip

      public long skip(long amount) throws IOException
      Skips amount number of bytes in this stream. Subsequent read()'s will not return these bytes unless reset() is used.
      Overrides:
      skip in class UnsynchronizedFilterInputStream
      Parameters:
      amount - the number of bytes to skip. skip does nothing and returns 0 if amount is less than zero.
      Returns:
      the number of bytes actually skipped.
      Throws:
      IOException - if this stream is closed or another IOException occurs.
      See Also: