org.redline_rpm.header

Class AbstractHeader

java.lang.Object

org.redline_rpm.header.AbstractHeader

Direct Known Subclasses:

Header, Signature

public abstract class AbstractHeader
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	AbstractHeader.AbstractEntry<T>
static interface	AbstractHeader.Entry<T>
static interface	AbstractHeader.Tag

Field Summary

Fields

Modifier and Type	Field and Description
protected int	endPos
protected Map<Integer,AbstractHeader.Entry<?>>	entries
protected static int	ENTRY_SIZE
protected static int	HEADER_HEADER_SIZE
protected static int	MAGIC_WORD
protected Map<AbstractHeader.Entry<?>,Integer>	pending
protected int	startPos
protected Map<Integer,AbstractHeader.Tag>	tags

Constructor Summary

Constructors

Constructor and Description
AbstractHeader()

Method Summary

Modifier and Type	Method and Description
AbstractHeader.Entry<?>	addEntry(AbstractHeader.Tag tag, int count) Adds a pending entry to this header.
int	count()
AbstractHeader.Entry<String[]>	createEntry(AbstractHeader.Tag tag, CharSequence value)
AbstractHeader.Entry<int[]>	createEntry(AbstractHeader.Tag tag, int value)
<T> AbstractHeader.Entry<T>	createEntry(AbstractHeader.Tag tag, int type, T values)
<T> AbstractHeader.Entry<T>	createEntry(AbstractHeader.Tag tag, T values)
protected AbstractHeader.Entry<?>	createEntry(int type)
AbstractHeader.Entry<?>	createEntry(int tag, int type, int count)
<T> AbstractHeader.Entry<T>	createEntry(int tag, int type, T values)
protected ByteBuffer	getData(ByteBuffer index) Writes the data section of the file, starting at the current position which must be immediately after the header section.
int	getEndPos()
AbstractHeader.Entry<?>	getEntry(AbstractHeader.Tag tag)
AbstractHeader.Entry<?>	getEntry(int tag)
protected ByteBuffer	getHeader() Memory maps the portion of the destination file that will contain the header structure header and advances the file channels position.
protected ByteBuffer	getIndex() Memory maps the portion of the destination file that will contain the index structure header and advances the file channels position.
Map<AbstractHeader.Entry<?>,Integer>	getPending()
int	getStartPos()
protected abstract boolean	pad()
int	read(ReadableByteChannel in) Reads the entire header contents for this channel and returns the number of entries found.
AbstractHeader.Entry<?>	readEntry(int tag, int type, int offset, int count, ByteBuffer data)
void	removeEntry(AbstractHeader.Entry<?> entry)
void	setEndPos(int endPos)
void	setStartPos(int startPos)
String	toString()
int	write(WritableByteChannel out) Writes this header section to the provided file at the current position and returns the required padding.
protected int	writeData(Collection<ByteBuffer> buffers, ByteBuffer index, AbstractHeader.Entry<?> entry, int offset)
void	writePending(FileChannel channel)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

HEADER_HEADER_SIZE

protected static final int HEADER_HEADER_SIZE

See Also:

Constant Field Values

ENTRY_SIZE

protected static final int ENTRY_SIZE

See Also:

Constant Field Values

MAGIC_WORD

protected static final int MAGIC_WORD

See Also:

Constant Field Values

tags

protected final Map<Integer,AbstractHeader.Tag> tags

entries

protected final Map<Integer,AbstractHeader.Entry<?>> entries

pending

protected final Map<AbstractHeader.Entry<?>,Integer> pending

startPos

protected int startPos

endPos

protected int endPos

Constructor Detail

AbstractHeader

public AbstractHeader()

Method Detail

pad

protected abstract boolean pad()

read

public int read(ReadableByteChannel in)
         throws IOException

Reads the entire header contents for this channel and returns the number of entries found.

Parameters:

in - the ReadableByteChannel to read

Returns:

the number read

Throws:

IOException - there was an IO error

write

public int write(WritableByteChannel out)
          throws IOException

Writes this header section to the provided file at the current position and returns the required padding. The caller is responsible for adding the padding immediately after this data.

Parameters:

out - the WritableByteChannel to output to

Returns:

the number written

Throws:

IOException - there was an IO error

count

public int count()

getHeader

protected ByteBuffer getHeader()
                        throws IOException

Memory maps the portion of the destination file that will contain the header structure header and advances the file channels position. The resulting buffer will be prefilled with the necesssary magic data and the correct index count, but will require an integer value to be written with the total data section size once data writing is complete. This method must be invoked before mapping the index or data sections.

Returns:

a buffer containing the header

Throws:

IOException - there was an IO error

getIndex

protected ByteBuffer getIndex()
                       throws IOException

Memory maps the portion of the destination file that will contain the index structure header and advances the file channels position. The resulting buffer will be ready for writing of the entry indexes. This method must be invoked before mapping the data section, but after mapping the header.

Returns:

a buffer containing the header

Throws:

IOException - there was an IO error

getData

protected ByteBuffer getData(ByteBuffer index)
                      throws IOException

Writes the data section of the file, starting at the current position which must be immediately after the header section. Each entry writes its corresponding index into the provided index buffer and then writes its data to the file channel.

Parameters:

index - ByteBuffer of the index

Returns:

the total number of bytes written to the data section of the file.

Throws:

IOException - there was an IO error

writeData

protected int writeData(Collection<ByteBuffer> buffers,
                        ByteBuffer index,
                        AbstractHeader.Entry<?> entry,
                        int offset)

writePending

public void writePending(FileChannel channel)

getPending

public Map<AbstractHeader.Entry<?>,Integer> getPending()

removeEntry

public void removeEntry(AbstractHeader.Entry<?> entry)

getEntry

public AbstractHeader.Entry<?> getEntry(AbstractHeader.Tag tag)

getEntry

public AbstractHeader.Entry<?> getEntry(int tag)

createEntry

public AbstractHeader.Entry<String[]> createEntry(AbstractHeader.Tag tag,
                                                  CharSequence value)

createEntry

public AbstractHeader.Entry<int[]> createEntry(AbstractHeader.Tag tag,
                                               int value)

createEntry

public <T> AbstractHeader.Entry<T> createEntry(AbstractHeader.Tag tag,
                                               T values)

createEntry

public <T> AbstractHeader.Entry<T> createEntry(AbstractHeader.Tag tag,
                                               int type,
                                               T values)

createEntry

public <T> AbstractHeader.Entry<T> createEntry(int tag,
                                               int type,
                                               T values)

addEntry

public AbstractHeader.Entry<?> addEntry(AbstractHeader.Tag tag,
                                        int count)

Adds a pending entry to this header. This entry will have the correctly sized buffer allocated, but will not be written until the caller writes a value and then invokes writePending(java.nio.channels.FileChannel) on this object.

Parameters:

tag - the tag

count - the count

Returns:

the entry added

readEntry

public AbstractHeader.Entry<?> readEntry(int tag,
                                         int type,
                                         int offset,
                                         int count,
                                         ByteBuffer data)

createEntry

public AbstractHeader.Entry<?> createEntry(int tag,
                                           int type,
                                           int count)

createEntry

protected AbstractHeader.Entry<?> createEntry(int type)

getEndPos

public int getEndPos()

setEndPos

public void setEndPos(int endPos)

getStartPos

public int getStartPos()

setStartPos

public void setStartPos(int startPos)

toString

public String toString()

Overrides:

toString in class Object