Package com.mckoi.util
Class PagedInputStream
- java.lang.Object
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- java.io.InputStream
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- com.mckoi.util.PagedInputStream
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- All Implemented Interfaces:
java.io.Closeable
,java.lang.AutoCloseable
public abstract class PagedInputStream extends java.io.InputStream
An implementation of InputStream that reads data from an underlying representation in fixed sized pages. This object maintains a single buffer that is the size of a page. This implementation supports 'skip' and buffered access to the data.The only method that needs to be implemented is the 'readPageContent' method.
- Author:
- Tobias Downer
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Constructor Summary
Constructors Constructor Description PagedInputStream(int page_size, long total_size)
Constructs the input stream.
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description int
available()
void
close()
void
mark(int limit)
boolean
markSupported()
int
read()
int
read(byte[] read_buf, int off, int len)
protected abstract void
readPageContent(byte[] buf, long pos, int length)
Reads the page at the given offset in the underlying data into the given byte[] array.void
reset()
long
skip(long n)
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Method Detail
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readPageContent
protected abstract void readPageContent(byte[] buf, long pos, int length) throws java.io.IOException
Reads the page at the given offset in the underlying data into the given byte[] array. The 'pos' variable given is guarenteed to be a multiple of buffer_size. For example, the first access will be to pos = 0, the second access to pos = BUFFER_SIZE, the third access to pos = BUFFER_SIZE * 2, etc. 'length' will always be either BUFFER_SIZE or a value smaller than BUFFER_SIZE if the page containing the end of the stream is read.- Throws:
java.io.IOException
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read
public int read() throws java.io.IOException
- Specified by:
read
in classjava.io.InputStream
- Throws:
java.io.IOException
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read
public int read(byte[] read_buf, int off, int len) throws java.io.IOException
- Overrides:
read
in classjava.io.InputStream
- Throws:
java.io.IOException
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skip
public long skip(long n) throws java.io.IOException
- Overrides:
skip
in classjava.io.InputStream
- Throws:
java.io.IOException
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available
public int available() throws java.io.IOException
- Overrides:
available
in classjava.io.InputStream
- Throws:
java.io.IOException
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close
public void close() throws java.io.IOException
- Specified by:
close
in interfacejava.lang.AutoCloseable
- Specified by:
close
in interfacejava.io.Closeable
- Overrides:
close
in classjava.io.InputStream
- Throws:
java.io.IOException
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mark
public void mark(int limit)
- Overrides:
mark
in classjava.io.InputStream
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reset
public void reset()
- Overrides:
reset
in classjava.io.InputStream
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markSupported
public boolean markSupported()
- Overrides:
markSupported
in classjava.io.InputStream
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