static int ApplyCap (TRI_cap_constraint_t* cap,
TRI_document_collection_t* document,
TRI_transaction_collection_t* trxCollection) {
TRI_headers_t* headers = document->_headersPtr; // PROTECTED by trx in trxCollection
size_t currentCount = headers->count();
int64_t currentSize = headers->size();
int res = TRI_ERROR_NO_ERROR;
// delete while at least one of the constraints is still violated
while ((cap->_count > 0 && currentCount > cap->_count) ||
(cap->_size > 0 && currentSize > cap->_size)) {
TRI_doc_mptr_t* oldest = headers->front();
if (oldest != nullptr) {
TRI_ASSERT(oldest->getDataPtr() != nullptr); // ONLY IN INDEX, PROTECTED by RUNTIME
size_t oldSize = ((TRI_df_marker_t*) (oldest->getDataPtr()))->_size; // ONLY IN INDEX, PROTECTED by RUNTIME
TRI_ASSERT(oldSize > 0);
if (trxCollection != nullptr) {
res = TRI_DeleteDocumentDocumentCollection(trxCollection, nullptr, oldest);
if (res != TRI_ERROR_NO_ERROR) {
LOG_WARNING("cannot cap collection: %s", TRI_errno_string(res));
break;
}
}
else {
headers->unlink(oldest);
}
currentCount--;
currentSize -= (int64_t) oldSize;
}
else {
// we should not get here
LOG_WARNING("logic error in %s", __FUNCTION__);
break;
}
}
return res;
}
static int InitialiseCap (TRI_cap_constraint_t* cap,
TRI_document_collection_t* document) {
TRI_ASSERT(cap->_count > 0 || cap->_size > 0);
TRI_headers_t* headers = document->_headersPtr; // ONLY IN INDEX (CAP)
size_t currentCount = headers->count();
int64_t currentSize = headers->size();
if ((cap->_count > 0 && currentCount <= cap->_count) &&
(cap->_size > 0 && currentSize <= cap->_size)) {
// nothing to do
return TRI_ERROR_NO_ERROR;
}
else {
TRI_vocbase_t* vocbase = document->_vocbase;
TRI_voc_cid_t cid = document->_info._cid;
triagens::arango::SingleCollectionWriteTransaction<UINT64_MAX> trx(new triagens::arango::StandaloneTransactionContext(), vocbase, cid);
trx.addHint(TRI_TRANSACTION_HINT_LOCK_NEVER, false);
trx.addHint(TRI_TRANSACTION_HINT_NO_BEGIN_MARKER, false);
trx.addHint(TRI_TRANSACTION_HINT_NO_ABORT_MARKER, false);
trx.addHint(TRI_TRANSACTION_HINT_SINGLE_OPERATION, false); // this is actually not true, but necessary to create trx id 0
int res = trx.begin();
if (res != TRI_ERROR_NO_ERROR) {
return res;
}
TRI_transaction_collection_t* trxCollection = trx.trxCollection();
res = ApplyCap(cap, document, trxCollection);
res = trx.finish(res);
return res;
}
}