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java.lang.Objectcom.bigdata.rdf.spo.FastRDFValueCoder
FastRDFValueCoder2
public class FastRDFValueCoder
Coder for statement index with inference enabled but without SIDS. We encode
the value in 3 bits per statement. The 1st bit is the override flag. The
remaining two bits are the statement type {inferred, explicit, or axiom}. The
bit sequence 111 is used as a place holder for a
null value and de-serializes to a [null].
Note: the 'override' flag is NOT stored in the statement indices, but it is passed by the procedure that writes on the statement indices so that we can decide whether or not to override the type when the statement is pre-existing in the index.
Note: this procedure can not be used if
AbstractTripleStore.Options#STATEMENT_IDENTIFIERS are enabled.
StatementEnum,
Serialized Form| Field Summary | |
|---|---|
protected static org.apache.log4j.Logger |
log
Deprecated. |
| Constructor Summary | |
|---|---|
FastRDFValueCoder()
Deprecated. Sole constructor (handles de-serialization also). |
|
| Method Summary | |
|---|---|
ICodedRaba |
decode(AbstractFixedByteArrayBuffer data)
Deprecated. Return an IRaba which can access the coded data. |
AbstractFixedByteArrayBuffer |
encode(IRaba raba,
DataOutputBuffer buf)
Deprecated. Encode the data. |
ICodedRaba |
encodeLive(IRaba raba,
DataOutputBuffer buf)
Deprecated. Encode the data, returning an ICodedRaba. |
boolean |
isKeyCoder()
Deprecated. No. |
boolean |
isValueCoder()
Deprecated. Yes. |
void |
readExternal(ObjectInput in)
Deprecated. |
void |
writeExternal(ObjectOutput out)
Deprecated. |
| Methods inherited from class java.lang.Object |
|---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Field Detail |
|---|
protected static final org.apache.log4j.Logger log
| Constructor Detail |
|---|
public FastRDFValueCoder()
| Method Detail |
|---|
public final boolean isKeyCoder()
isKeyCoder in interface IRabaCoderpublic final boolean isValueCoder()
isValueCoder in interface IRabaCoder
public void writeExternal(ObjectOutput out)
throws IOException
writeExternal in interface ExternalizableIOException
public void readExternal(ObjectInput in)
throws IOException,
ClassNotFoundException
readExternal in interface ExternalizableIOException
ClassNotFoundException
public AbstractFixedByteArrayBuffer encode(IRaba raba,
DataOutputBuffer buf)
IRabaCoder
Note: Implementations of this method are typically heavy. While it is
always valid to IRabaCoder.encode(IRaba, DataOutputBuffer) an IRaba
, DO NOT invoke this arbitrarily on data which may already be
coded. The ICodedRaba interface will always be implemented for
coded data.
encode in interface IRabaCoderraba - The data.buf - A buffer on which the coded data will be written.
public ICodedRaba encodeLive(IRaba raba,
DataOutputBuffer buf)
IRabaCoderICodedRaba. Implementations of this
method should be optimized for the very common use case where the caller
requires immediate access to the coded data record. In that case, many of
the IRabaCoder implementations can be optimized by passing the
underlying decoding object directly into an alternative constructor for
the ICodedRaba. The byte[] slice for the coded data record is
available from ICodedRaba.data().
This method covers the vast major of the use cases for coding data, which
is to code B+Tree keys or values for a node or leaf that has been evicted
from the AbstractBTree's write retention queue. The common use
case is to wrap a coded record that was read from an IRawStore.
The IndexSegmentBuilder is a special case, since the coded record
will not be used other than to write it on the disk.
encodeLive in interface IRabaCoderpublic ICodedRaba decode(AbstractFixedByteArrayBuffer data)
IRabaCoderIRaba which can access the coded data. In general,
implementations SHOULD NOT materialize a backing byte[][]. Instead, the
implementation should access the data in place within the caller's
buffer. Frequently used fields MAY be cached, but the whole point of the
IRabaCoder is to minimize the in-memory footprint for the B+Tree
by using a coded (aka compressed) representation of the keys and values
whenever possible.
decode in interface IRabaCoderdata - The record containing the coded data.
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