stasis-bLSM/tuplemerger.cpp
sears 632afe6d9c cleanup statistics gathering and reporting.
constify inputs to merge functions (so they can't call freetuple())


git-svn-id: svn+ssh://svn.corp.yahoo.com/yahoo/yrl/labs/pnuts/code/logstore@662 8dad8b1f-cf64-0410-95b6-bcf113ffbcfe
2010-03-05 19:07:47 +00:00

54 lines
1.3 KiB
C++

#include "tuplemerger.h"
#include "logstore.h"
// XXX test / reason about this...
datatuple* tuplemerger::merge(const datatuple *t1, const datatuple *t2)
{
datatuple *t;
if(t1->isDelete() && t2->isDelete()) {
t = t2->create_copy();
} else if(t1->isDelete()) //delete -> t2
{
t = t2->create_copy();
}
else if(t2->isDelete())
{
t = t2->create_copy();
}
else //neither is a delete
{
t = (*merge_fp)(t1,t2);
}
return t;
}
/**
* appends the data in t2 to data from t1
*
* deletes are handled by the tuplemerger::merge function
* so here neither t1 nor t2 is a delete datatuple
**/
datatuple* append_merger(const datatuple *t1, const datatuple *t2)
{
assert(!(t1->isDelete() || t2->isDelete()));
len_t keylen = t1->keylen();
len_t datalen = t1->datalen() + t2->datalen();
byte * data = (byte*)malloc(datalen);
memcpy(data, t1->data(), t1->datalen());
memcpy(data + t1->datalen(), t2->data(), t2->datalen());
return datatuple::create(t1->key(), keylen, data, datalen);
}
/**
* replaces the data with data from t2
*
* deletes are handled by the tuplemerger::merge function
* so here neither t1 nor t2 is a delete datatuple
**/
datatuple* replace_merger(const datatuple *t1, const datatuple *t2)
{
return t2->create_copy();
}