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com.fasterxml.aalto.in

public final Class MergedStream

extends InputStream
Class Inheritance
Imports
java.io.*
Simple InputStream implementation that is used to "unwind" some data previously read from an input stream; so that as long as some of that data remains, it's returned; but as long as it's read, we'll just use data from the underlying original stream. This is similar to java.io.PushbackInputStream, but here there's only one implicit pushback, when instance is constructed.

Field Summary

Modifier and TypeField and Description
private final ReaderConfig
mConfig

private byte[]
mData

private final int
mEnd

private final InputStream
mIn

private int
mPtr

Constructor Summary

AccessConstructor and Description
public
MergedStream(ReaderConfig cfg, InputStream in, byte[] buf, int start, int end)

Method Summary

Modifier and TypeMethod and Description
public int
available()

Overrides java.io.InputStream.available.

Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking, which may be 0, or 0 when end of stream is detected.
public void
close()

Overrides java.io.InputStream.close.

Implements java.io.Closeable.close.

Closes this input stream and releases any system resources associated with the stream.
private void
freeBuffers()

public synchronized void
mark(int
the maximum limit of bytes that can be read before the mark position becomes invalid.
readlimit)

Overrides java.io.InputStream.mark.

Marks the current position in this input stream.
public boolean
markSupported()

Overrides java.io.InputStream.markSupported.

Tests if this input stream supports the mark and reset methods.
public int
read()

Implements abstract java.io.InputStream.read.

Reads the next byte of data from the input stream.
public int
read(byte[]
the buffer into which the data is read.
b)

Overrides java.io.InputStream.read.

Reads some number of bytes from the input stream and stores them into the buffer array b.
public int
read(byte[]
the buffer into which the data is read.
b, int
the start offset in array b at which the data is written.
off, int
the maximum number of bytes to read.
len)

Overrides java.io.InputStream.read.

Reads up to len bytes of data from the input stream into an array of bytes.
public synchronized void
reset()

Overrides java.io.InputStream.reset.

Repositions this stream to the position at the time the mark method was last called on this input stream.
public long
skip(long
the number of bytes to be skipped.
n)

Overrides java.io.InputStream.skip.

Skips over and discards n bytes of data from this input stream.
Inherited from java.io.InputStream:
nullInputStreamreadAllBytesreadNBytesreadNBytesskipNBytestransferTo

Field Detail

mConfigback to summary
private final ReaderConfig mConfig
mDataback to summary
private byte[] mData
mEndback to summary
private final int mEnd
mInback to summary
private final InputStream mIn
mPtrback to summary
private int mPtr

Constructor Detail

MergedStreamback to summary
public MergedStream(ReaderConfig cfg, InputStream in, byte[] buf, int start, int end)

Method Detail

availableback to summary
public int available() throws IOException

Overrides java.io.InputStream.available.

Doc from java.io.InputStream.available.

Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking, which may be 0, or 0 when end of stream is detected. The read might be on the same thread or another thread. A single read or skip of this many bytes will not block, but may read or skip fewer bytes.

Note that while some implementations of InputStream will return the total number of bytes in the stream, many will not. It is never correct to use the return value of this method to allocate a buffer intended to hold all data in this stream.

A subclass's implementation of this method may choose to throw an IOException if this input stream has been closed by invoking the close() method.

Returns:int

an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking or 0 when it reaches the end of the input stream.

Annotations
@Override
Exceptions
IOException:
if an I/O error occurs.
closeback to summary
public void close() throws IOException

Overrides java.io.InputStream.close.

Implements java.io.Closeable.close.

Doc from java.io.InputStream.close.

Closes this input stream and releases any system resources associated with the stream.

Annotations
@Override
Exceptions
IOException:
if an I/O error occurs.
freeBuffersback to summary
private void freeBuffers()
markback to summary
public synchronized void mark(int readlimit)

Overrides java.io.InputStream.mark.

Doc from java.io.InputStream.mark.

Marks the current position in this input stream. A subsequent call to the reset method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.

The readlimit arguments tells this input stream to allow that many bytes to be read before the mark position gets invalidated.

The general contract of mark is that, if the method markSupported returns true, the stream somehow remembers all the bytes read after the call to mark and stands ready to supply those same bytes again if and whenever the method reset is called. However, the stream is not required to remember any data at all if more than readlimit bytes are read from the stream before reset is called.

Marking a closed stream should not have any effect on the stream.

Parameters
readlimit:int

the maximum limit of bytes that can be read before the mark position becomes invalid.

Annotations
@Override
markSupportedback to summary
public boolean markSupported()

Overrides java.io.InputStream.markSupported.

Doc from java.io.InputStream.markSupported.

Tests if this input stream supports the mark and reset methods. Whether or not mark and reset are supported is an invariant property of a particular input stream instance.

Returns:boolean

true if this stream instance supports the mark and reset methods; false otherwise.

Annotations
@Override
readback to summary
public int read() throws IOException

Implements abstract java.io.InputStream.read.

Doc from java.io.InputStream.read.

Reads the next byte of data from the input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

Returns:int

the next byte of data, or -1 if the end of the stream is reached.

Annotations
@Override
Exceptions
IOException:
if an I/O error occurs.
readback to summary
public int read(byte[] b) throws IOException

Overrides java.io.InputStream.read.

Doc from java.io.InputStream.read.

Reads some number of bytes from the input stream and stores them into the buffer array b. The number of bytes actually read is returned as an integer. This method blocks until input data is available, end of file is detected, or an exception is thrown.

If the length of b is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at the end of the file, the value -1 is returned; otherwise, at least one byte is read and stored into b.

The first byte read is stored into element b[0], the next one into b[1], and so on. The number of bytes read is, at most, equal to the length of b. Let k be the number of bytes actually read; these bytes will be stored in elements b[0] through b[k-1], leaving elements b[k] through b[b.length-1] unaffected.

Parameters
b:byte[]

the buffer into which the data is read.

Returns:int

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.

Annotations
@Override
Exceptions
IOException:
If the first byte cannot be read for any reason other than the end of the file, if the input stream has been closed, or if some other I/O error occurs.
readback to summary
public int read(byte[] b, int off, int len) throws IOException

Overrides java.io.InputStream.read.

Doc from java.io.InputStream.read.

Reads up to len bytes of data from the input stream into an array of bytes. An attempt is made to read as many as len bytes, but a smaller number may be read. The number of bytes actually read is returned as an integer.

This method blocks until input data is available, end of file is detected, or an exception is thrown.

If len is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at end of file, the value -1 is returned; otherwise, at least one byte is read and stored into b.

The first byte read is stored into element b[off], the next one into b[off+1], and so on. The number of bytes read is, at most, equal to len. Let k be the number of bytes actually read; these bytes will be stored in elements b[off] through b[off+k-1], leaving elements b[off+k] through b[off+len-1] unaffected.

In every case, elements b[0] through b[off-1] and elements b[off+len] through b[b.length-1] are unaffected.

Parameters
b:byte[]

the buffer into which the data is read.

off:int

the start offset in array b at which the data is written.

len:int

the maximum number of bytes to read.

Returns:int

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.

Annotations
@Override
Exceptions
IOException:
If the first byte cannot be read for any reason other than end of file, or if the input stream has been closed, or if some other I/O error occurs.
resetback to summary
public synchronized void reset() throws IOException

Overrides java.io.InputStream.reset.

Doc from java.io.InputStream.reset.

Repositions this stream to the position at the time the mark method was last called on this input stream.

The general contract of reset is:

  • If the method markSupported returns true, then:
    • If the method mark has not been called since the stream was created, or the number of bytes read from the stream since mark was last called is larger than the argument to mark at that last call, then an IOException might be thrown.
    • If such an IOException is not thrown, then the stream is reset to a state such that all the bytes read since the most recent call to mark (or since the start of the file, if mark has not been called) will be resupplied to subsequent callers of the read method, followed by any bytes that otherwise would have been the next input data as of the time of the call to reset.
  • If the method markSupported returns false, then:
    • The call to reset may throw an IOException.
    • If an IOException is not thrown, then the stream is reset to a fixed state that depends on the particular type of the input stream and how it was created. The bytes that will be supplied to subsequent callers of the read method depend on the particular type of the input stream.
Annotations
@Override
Exceptions
IOException:
if this stream has not been marked or if the mark has been invalidated.
skipback to summary
public long skip(long n) throws IOException

Overrides java.io.InputStream.skip.

Doc from java.io.InputStream.skip.

Skips over and discards n bytes of data from this input stream. The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. This may result from any of a number of conditions; reaching end of file before n bytes have been skipped is only one possibility. The actual number of bytes skipped is returned. If n is negative, the skip method for class InputStream always returns 0, and no bytes are skipped. Subclasses may handle the negative value differently.

Parameters
n:long

the number of bytes to be skipped.

Returns:long

the actual number of bytes skipped which might be zero.

Annotations
@Override
Exceptions
IOException:
if an I/O error occurs.