// **********************************************************
// Delete a record from a page. Returns OK if everything went okay.
// Compacts remaining records but leaves a hole in the slot array.
// Use memmove() rather than memcpy() as space may overlap.
Status HFPage::deleteRecord(const RID& rid)
{
// fill in the body
//--- deal with errors ----
if(rid.pageNo < 0 || rid.slotNo < 0)
return MINIBASE_FIRST_ERROR(HEAPFILE, INVALID_SLOTNO);
//return FAIL;
if(rid.slotNo >= this->slotCnt)
return MINIBASE_FIRST_ERROR(HEAPFILE, INVALID_SLOTNO);
//return FAIL;
//--- deal with empty page case ---
if(empty())
return MINIBASE_FIRST_ERROR(HEAPFILE, NO_RECORDS);
//return FAIL;
//--- get record offset ---
int offset = getRecordOffset(rid);
//--- clean corresponding slot & get record length---
int len = cleanSlot(rid);
//--- deal with already deleted case ---
if(offset == INVALID_SLOT || len == EMPTY_SLOT)
return MINIBASE_FIRST_ERROR(HEAPFILE, ALREADY_DELETED);
//return FAIL;
//-- shrink slot directory ---
shrinkSlotDir();
//--- delete record & relocate behind records & slot dir ---
//--- & update usedPtr, freeSpace -----
deleteRec(offset, len);
return OK;
}
// Pre-condition: front points to the head of a linked list structure.
// Post-condition: The first node that contains the value num will be
// removed from the list. A pointer to the front of the
// list will be returned. If no such value is stored,
// the list will remain unchanged.
struct ll* deleteRec(struct ll *front, int num) {
// No item in list, no delete to do.
if (front == NULL)
return NULL;
// Deleting the first item.
if (front->data == num) {
// This is the list to return.
struct ll* retval = front->next;
// Need to free the deleted node.
free(front);
return retval;
}
// We can try to delete num from the rest of the list.
struct ll* rest = deleteRec(front->next, num);
// Attach the rest of the list to what is returned from the recursive call.
front->next = rest;
return front; // This is unchanged.
}
// delete all records checked in the list
bool Collectiondb::deleteRecs ( HttpRequest *r ) {
for ( long i = 0 ; i < r->getNumFields() ; i++ ) {
char *f = r->getField ( i );
if ( strncmp ( f , "del" , 3 ) != 0 ) continue;
char *coll = f + 3;
//if ( ! is_digit ( f[3] ) ) continue;
//long h = atol ( f + 3 );
deleteRec ( coll );
}
return true;
}
// **********************************************************
// Delete a record from a page. Returns OK if everything went okay.
// Compacts remaining records but leaves a hole in the slot array.
// Use memmove() rather than memcpy() as space may overlap.
Status HFPage::deleteRecord(const RID& rid)
{
// fill in the body
//---?? 注意未处理delete不存在record得特殊情况----
//--- get record offset ---
int offset = getRecordOffset(rid);
//--- clean corresponding slot & get record length---
int len = cleanSlot(rid);
//-- shrink slot directory ---
shrinkSlotDir();
//--- delete record & relocate behind records & slot dir ---
//--- & update usedPtr, freeSpace -----
deleteRec(offset, len);
return OK;
}
// . reset a collection
// . returns false if failed
bool Collectiondb::resetColl ( char *coll , bool resetTurkdb ) {
// ensure it's not NULL
if ( ! coll ) {
log(LOG_LOGIC,"admin: Collection name to delete is NULL.");
return false;
}
// now must be "test" only for now
if ( strcmp(coll,"test") ) { char *xx=NULL;*xx=0; }
// no spiders can be out. they may be referencing the CollectionRec
// in XmlDoc.cpp... quite likely.
if ( g_conf.m_spideringEnabled ||
g_spiderLoop.m_numSpidersOut > 0 ) {
log("admin: Can not delete collection while "
"spiders are enabled or active.");
return false;
}
// do not allow this if in repair mode
if ( g_repairMode > 0 ) {
log("admin: Can not delete collection while in repair mode.");
return false;
}
// get the CollectionRec for "test"
CollectionRec *cr = getRec ( "test" );
// must be there. if not, we create test i guess
if ( ! cr ) {
log("db: could not get test coll rec");
char *xx=NULL;*xx=0;
}
// make sure an update not in progress
if ( cr->m_inProgress ) { char *xx=NULL;*xx=0; }
CollectionRec tmp;
// copy it to "tmp"
long size = (char *)&(cr->m_END_COPY) - (char *)cr;
// do not copy the hashtable crap since you will have to re-init it!
memcpy ( &tmp , cr , size ); // sizeof(CollectionRec) );
// delete the test coll now
if ( ! deleteRec ( "test" , resetTurkdb ) )
return log("admin: reset coll failed");
// make a collection called "test2" so that we copy "test"'s parms
bool status = addRec ( "test" ,
NULL ,
0 ,
true , // bool isNew ,
(collnum_t) -1 ,
// not a dump
false ,
// do not save it!
false );
// bail on error
if ( ! status ) return log("admin: failed to add new coll for reset");
// get its rec
CollectionRec *nr = getRec ( "test" );
// must be there
if ( ! nr ) { char *xx=NULL;*xx=0; }
// save this though, this might have changed!
collnum_t cn = nr->m_collnum;
// overwrite its rec
memcpy ( nr , &tmp , size ) ; // sizeof(CollectionRec) );
// put that collnum back
nr->m_collnum = cn;
// set the flag
m_needsSave = true;
// save it again after copy
nr->save();
// and clear the robots.txt cache in case we recently spidered a
// robots.txt, we don't want to use it, we want to use the one we
// have in the test-parser subdir so we are consistent
RdbCache *robots = Msg13::getHttpCacheRobots();
RdbCache *others = Msg13::getHttpCacheOthers();
robots->clear ( cn );
others->clear ( cn );
//g_templateTable.reset();
//g_templateTable.save( g_hostdb.m_dir , "turkedtemplates.dat" );
// repopulate CollectionRec::m_sortByDateTable. should be empty
// since we are resetting here.
//initSortByDateTable ( coll );
// done
return true;
}
