void PIO_get_unique_file_id(const Jrd::jrd_file* file, UCharBuffer& id)
{
/**************************************
*
* P I O _ g e t _ u n i q u e _ f i l e _ i d
*
**************************************
*
* Functional description
* Return a binary string that uniquely identifies the file.
*
**************************************/
struct stat statistics;
if (fstat(file->fil_desc, &statistics) != 0) {
unix_error("fstat", file, isc_io_access_err);
}
const size_t len1 = sizeof(statistics.st_dev);
const size_t len2 = sizeof(statistics.st_ino);
UCHAR* p = id.getBuffer(len1 + len2);
memcpy(p, &statistics.st_dev, len1);
p += len1;
memcpy(p, &statistics.st_ino, len2);
}
static void makeUniqueFileId(const struct stat& statistics, UCharBuffer& id)
{
const size_t len1 = sizeof(statistics.st_dev);
const size_t len2 = sizeof(statistics.st_ino);
UCHAR* p = id.getBuffer(len1 + len2);
memcpy(p, &statistics.st_dev, len1);
p += len1;
memcpy(p, &statistics.st_ino, len2);
}
// Parse routine BLR.
void Routine::parseBlr(thread_db* tdbb, CompilerScratch* csb, bid* blob_id)
{
Jrd::Attachment* attachment = tdbb->getAttachment();
UCharBuffer tmp;
if (blob_id)
{
blb* blob = blb::open(tdbb, attachment->getSysTransaction(), blob_id);
ULONG length = blob->blb_length + 10;
UCHAR* temp = tmp.getBuffer(length);
length = blob->BLB_get_data(tdbb, temp, length);
tmp.resize(length);
}
parseMessages(tdbb, csb, BlrReader(tmp.begin(), (unsigned) tmp.getCount()));
JrdStatement* statement = getStatement();
PAR_blr(tdbb, NULL, tmp.begin(), (ULONG) tmp.getCount(), NULL, &csb, &statement, false, 0);
setStatement(statement);
if (!blob_id)
setImplemented(false);
}
bool MergeJoin::getRecord(thread_db* tdbb) const
{
if (--tdbb->tdbb_quantum < 0)
JRD_reschedule(tdbb, 0, true);
jrd_req* const request = tdbb->getRequest();
Impure* const impure = request->getImpure<Impure>(m_impure);
if (!(impure->irsb_flags & irsb_open))
return false;
// If there is a record group already formed, fetch the next combination
if (fetchRecord(tdbb, m_args.getCount() - 1))
return true;
// Assuming we are done with the current value group, advance each
// stream one record. If any comes up dry, we're done.
const NestConst<SortedStream>* highest_ptr = m_args.begin();
FB_SIZE_T highest_index = 0;
for (FB_SIZE_T i = 0; i < m_args.getCount(); i++)
{
const NestConst<SortedStream>* const ptr = &m_args[i];
const SortedStream* const sort_rsb = *ptr;
const NestValueArray* const sort_key = m_keys[i];
Impure::irsb_mrg_repeat* const tail = &impure->irsb_mrg_rpt[i];
MergeFile* const mfb = &tail->irsb_mrg_file;
// reset equality group record positions
tail->irsb_mrg_equal = 0;
tail->irsb_mrg_equal_current = 0;
tail->irsb_mrg_equal_end = 0;
// If there is a record waiting, use it. Otherwise get another.
SLONG record = tail->irsb_mrg_last_fetched;
if (record >= 0)
{
tail->irsb_mrg_last_fetched = -1;
const UCHAR* const last_data = getData(tdbb, mfb, record);
mfb->mfb_current_block = 0;
UCHAR* const first_data = getData(tdbb, mfb, 0);
if (first_data != last_data)
memcpy(first_data, last_data, sort_rsb->getLength());
mfb->mfb_equal_records = 1;
record = 0;
}
else
{
mfb->mfb_current_block = 0;
mfb->mfb_equal_records = 0;
if ((record = getRecord(tdbb, i)) < 0)
return false;
}
// map data into target records and do comparison
sort_rsb->mapData(tdbb, request, getData(tdbb, mfb, record));
if (ptr != highest_ptr && compare(tdbb, m_keys[highest_index], sort_key) < 0)
{
highest_ptr = ptr;
highest_index = i;
}
}
// Loop thru the streams advancing each up to the target value.
// If any exceeds the target value, start over.
while (true)
{
bool recycle = false;
for (FB_SIZE_T i = 0; i < m_args.getCount(); i++)
{
const NestConst<SortedStream>* const ptr = &m_args[i];
const SortedStream* const sort_rsb = *ptr;
const NestValueArray* const sort_key = m_keys[i];
Impure::irsb_mrg_repeat* const tail = &impure->irsb_mrg_rpt[i];
if (highest_ptr != ptr)
{
int result;
while ( (result = compare(tdbb, m_keys[highest_index], sort_key)) )
{
if (result < 0)
{
highest_ptr = ptr;
highest_index = i;
recycle = true;
break;
}
MergeFile* const mfb = &tail->irsb_mrg_file;
mfb->mfb_current_block = 0;
mfb->mfb_equal_records = 0;
const SLONG record = getRecord(tdbb, i);
if (record < 0)
return false;
sort_rsb->mapData(tdbb, request, getData(tdbb, mfb, record));
}
if (recycle)
break;
}
}
if (!recycle)
break;
}
// finally compute equality group for each stream in sort/merge
for (FB_SIZE_T i = 0; i < m_args.getCount(); i++)
{
const SortedStream* const sort_rsb = m_args[i];
Impure::irsb_mrg_repeat* const tail = &impure->irsb_mrg_rpt[i];
MergeFile* const mfb = &tail->irsb_mrg_file;
UCharBuffer key;
const ULONG key_length = sort_rsb->getKeyLength();
UCHAR* const first_data = key.getBuffer(key_length);
memcpy(first_data, getData(tdbb, mfb, 0), key_length);
SLONG record;
while ((record = getRecord(tdbb, i)) >= 0)
{
const UCHAR* p = first_data;
const UCHAR* q = getData(tdbb, mfb, record);
if (!sort_rsb->compareKeys(p, q))
{
tail->irsb_mrg_last_fetched = record;
break;
}
tail->irsb_mrg_equal_end = record;
}
if (mfb->mfb_current_block)
{
if (!mfb->mfb_space)
{
MemoryPool& pool = *getDefaultMemoryPool();
mfb->mfb_space = FB_NEW_POOL(pool) TempSpace(pool, SCRATCH, false);
}
Sort::writeBlock(mfb->mfb_space, mfb->mfb_block_size * mfb->mfb_current_block,
mfb->mfb_block_data, mfb->mfb_block_size);
}
}
// Optimize cross product of equivalence groups by ordering the streams
// from left (outermost) to right (innermost) by descending cardinality
// of merge blocks. This ordering will vary for each set of equivalence
// groups and cannot be statically assigned by the optimizer.
typedef Stack<Impure::irsb_mrg_repeat*> ImrStack;
ImrStack best_tails;
Impure::irsb_mrg_repeat* tail = impure->irsb_mrg_rpt;
for (const Impure::irsb_mrg_repeat* const tail_end = tail + m_args.getCount();
tail < tail_end; tail++)
{
Impure::irsb_mrg_repeat* best_tail = NULL;
ULONG most_blocks = 0;
for (Impure::irsb_mrg_repeat* tail2 = impure->irsb_mrg_rpt; tail2 < tail_end; tail2++)
{
ImrStack::iterator stack(best_tails);
for (; stack.hasData(); ++stack)
{
if (stack.object() == tail2)
break;
}
if (stack.hasData())
continue;
MergeFile* const mfb = &tail2->irsb_mrg_file;
ULONG blocks = mfb->mfb_equal_records / mfb->mfb_blocking_factor;
if (++blocks > most_blocks)
{
most_blocks = blocks;
best_tail = tail2;
}
}
best_tails.push(best_tail);
tail->irsb_mrg_order = best_tail - impure->irsb_mrg_rpt;
}
return true;
}
