LbmDeletionIndexReader Class Reference

LbmBTreeRidReader is a class for reading RIDs from a deletion index. More...

#include <LbmRidReader.h>

List of all members.

Public Member Functions

 ~LbmDeletionIndexReader ()
void init (SharedBTreeReader &btreeReader, TupleData &bitmapSegTuple)
 Initializes reader to search for RIDs stored in a btree specified BTreeReader.
void endSearch ()
 Releases any locks held.
bool isEmpty ()
 Determines whether the deletion index is empty.
bool searchForRid (LcsRid rid)
 Searches for a RID in the btree.

Private Member Functions

void initRidReader ()
 Reinitializes the internal rid reader.

Private Attributes

SharedBTreeReader btreeReader
 Deletion index btree reader.
TupleData * pBitmapSegTuple
 Pointer to tuple data containing a btree bitmap segment.
TupleData searchEntry
 TupleData for searching btree.
bool currTuple
 Whether a tuple is currently being searched.
LbmTupleRidReader ridReader
 Reads rids from a tuple sequentially.
LcsRid btreeRid
 The last rid read.
bool emptyIndex
 True if the deletion index is empty.
bool emptyIndexUnknown
 True if it is not known whether the deletion index is empty.

Detailed Description

LbmBTreeRidReader is a class for reading RIDs from a deletion index.

Definition at line 229 of file LbmRidReader.h.

Constructor & Destructor Documentation

LbmDeletionIndexReader::~LbmDeletionIndexReader (  ) 

Definition at line 205 of file LbmRidReader.cpp.

References endSearch().

00206 {
00207     endSearch();
00208 }

Member Function Documentation

void LbmDeletionIndexReader::initRidReader (  )  [private]

Reinitializes the internal rid reader.

Should be called whenever a new tuple is read or to restart a read on the current tuple.

Definition at line 225 of file LbmRidReader.cpp.

References btreeRid, currTuple, LbmIterableRidReader::getNext(), LbmTupleRidReader::init(), pBitmapSegTuple, and ridReader.

Referenced by searchForRid().

00226 {
00227     currTuple = true;
00228     ridReader.init(*pBitmapSegTuple);
00229     btreeRid = ridReader.getNext();
00230 }

void LbmDeletionIndexReader::init ( SharedBTreeReader &  btreeReader,
TupleData &  bitmapSegTuple 
)

Initializes reader to search for RIDs stored in a btree specified BTreeReader.

Parameters:
btreeReader input btree reader
bitmapSegTuple tuple data for reading segments

Definition at line 210 of file LbmRidReader.cpp.

References btreeReader, TupleData::compute(), currTuple, emptyIndexUnknown, pBitmapSegTuple, and searchEntry.

Referenced by LbmSplicerExecStream::open().

00213 {
00214     // the btree must be a deletion index
00215     assert(btreeReaderInit->getTupleDescriptor().size() == 3);
00216     assert(bitmapSegTuple.size() == 3);
00217 
00218     btreeReader = btreeReaderInit;
00219     pBitmapSegTuple = &bitmapSegTuple;
00220     searchEntry.compute(btreeReader->getKeyDescriptor());
00221     emptyIndexUnknown = true;
00222     currTuple = false;
00223 }

void LbmDeletionIndexReader::endSearch (  ) 

Releases any locks held.

Definition at line 232 of file LbmRidReader.cpp.

References btreeReader.

Referenced by LbmSplicerExecStream::closeImpl(), and ~LbmDeletionIndexReader().

00233 {
00234     if (btreeReader) {
00235         btreeReader->endSearch();
00236     }
00237 }

bool LbmDeletionIndexReader::isEmpty (  ) 

Determines whether the deletion index is empty.

Definition at line 239 of file LbmRidReader.cpp.

References btreeReader, emptyIndex, and emptyIndexUnknown.

Referenced by searchForRid().

00240 {
00241     if (emptyIndexUnknown) {
00242         emptyIndex = !btreeReader->searchFirst();
00243         emptyIndexUnknown = false;
00244     }
00245     return emptyIndex;
00246 }

bool LbmDeletionIndexReader::searchForRid ( LcsRid  rid  ) 

Searches for a RID in the btree.

Parameters:
rid the RID to search for
Returns:
true if the RID was found, false otherwise

Definition at line 248 of file LbmRidReader.cpp.

References btreeReader, btreeRid, currTuple, DUP_SEEK_BEGIN, LbmIterableRidReader::getNext(), LbmEntry::getStartRid(), LbmIterableRidReader::hasNext(), initRidReader(), isEmpty(), pBitmapSegTuple, ridReader, and searchEntry.

Referenced by LbmSplicerExecStream::countKeyRows(), and LbmSplicerExecStream::getValidatedTuple().

00249 {
00250     if (isEmpty()) {
00251         return false;
00252     }
00253 
00254     LcsRid prevSrid = LcsRid(0);
00255     if (currTuple) {
00256         prevSrid = LbmEntry::getStartRid(*pBitmapSegTuple);
00257     }
00258 
00259     searchEntry[0].pData = reinterpret_cast<PConstBuffer>(&rid);
00260     btreeReader->searchForKey(searchEntry, DUP_SEEK_BEGIN, false);
00261     btreeReader->getTupleAccessorForRead().unmarshal(*pBitmapSegTuple);
00262     LcsRid foundSrid = LbmEntry::getStartRid(*pBitmapSegTuple);
00263 
00264     // determine whether the tuple rid reader must be restarted. it should
00265     // be restarted if the tuple has changed or if the rid we are searching
00266     // for would be positioned before the last rid read.
00267     bool sameTuple = (currTuple && prevSrid == foundSrid);
00268     if (!sameTuple || (rid < btreeRid)) {
00269         initRidReader();
00270     }
00271 
00272     // advance within a tuple to search for the rid
00273     while (btreeRid < rid) {
00274         if (ridReader.hasNext()) {
00275             btreeRid = ridReader.getNext();
00276         } else {
00277             break;
00278         }
00279     }
00280     return (btreeRid == rid);
00281 }

Member Data Documentation

SharedBTreeReader LbmDeletionIndexReader::btreeReader [private]

Deletion index btree reader.

Definition at line 234 of file LbmRidReader.h.

Referenced by endSearch(), init(), isEmpty(), and searchForRid().

TupleData* LbmDeletionIndexReader::pBitmapSegTuple [private]

Pointer to tuple data containing a btree bitmap segment.

Definition at line 239 of file LbmRidReader.h.

Referenced by init(), initRidReader(), and searchForRid().

TupleData LbmDeletionIndexReader::searchEntry [private]

TupleData for searching btree.

Definition at line 244 of file LbmRidReader.h.

Referenced by init(), and searchForRid().

bool LbmDeletionIndexReader::currTuple [private]

Whether a tuple is currently being searched.

Definition at line 249 of file LbmRidReader.h.

Referenced by init(), initRidReader(), and searchForRid().

LbmTupleRidReader LbmDeletionIndexReader::ridReader [private]

Reads rids from a tuple sequentially.

Definition at line 254 of file LbmRidReader.h.

Referenced by initRidReader(), and searchForRid().

LcsRid LbmDeletionIndexReader::btreeRid [private]

The last rid read.

Definition at line 259 of file LbmRidReader.h.

Referenced by initRidReader(), and searchForRid().

bool LbmDeletionIndexReader::emptyIndex [private]

True if the deletion index is empty.

Definition at line 264 of file LbmRidReader.h.

Referenced by isEmpty().

bool LbmDeletionIndexReader::emptyIndexUnknown [private]

True if it is not known whether the deletion index is empty.

Definition at line 269 of file LbmRidReader.h.

Referenced by init(), and isEmpty().

The documentation for this class was generated from the following files:
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