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arangodb/arangod/Indexes/CapConstraint.cpp

205 lines
7.0 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
/// http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Dr. Frank Celler
////////////////////////////////////////////////////////////////////////////////
#include "CapConstraint.h"
#include "Utils/transactions.h"
#include "VocBase/document-collection.h"
#include "VocBase/transaction.h"
using namespace triagens::arango;
////////////////////////////////////////////////////////////////////////////////
/// @brief minimum size
////////////////////////////////////////////////////////////////////////////////
int64_t const CapConstraint::MinSize = 16384;
CapConstraint::CapConstraint(TRI_idx_iid_t iid,
TRI_document_collection_t* collection,
size_t count, int64_t size)
: Index(iid, collection,
std::vector<std::vector<triagens::basics::AttributeName>>(), false,
false),
_count(count),
_size(static_cast<int64_t>(size)) {}
CapConstraint::~CapConstraint() {}
size_t CapConstraint::memory() const { return 0; }
////////////////////////////////////////////////////////////////////////////////
/// @brief return a JSON representation of the index
////////////////////////////////////////////////////////////////////////////////
triagens::basics::Json CapConstraint::toJson(TRI_memory_zone_t* zone,
bool withFigures) const {
auto json = Index::toJson(zone, withFigures);
json("size", triagens::basics::Json(zone, static_cast<double>(_count)))(
"byteSize", triagens::basics::Json(zone, static_cast<double>(_size)))(
"unique", triagens::basics::Json(zone, false));
return json;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief return a JSON representation of the index figures
////////////////////////////////////////////////////////////////////////////////
triagens::basics::Json CapConstraint::toJsonFigures(
TRI_memory_zone_t* zone) const {
triagens::basics::Json json(triagens::basics::Json::Object);
json("memory", triagens::basics::Json(static_cast<double>(memory())));
return json;
}
int CapConstraint::insert(triagens::arango::Transaction*,
TRI_doc_mptr_t const* doc, bool) {
if (_size > 0) {
// there is a size restriction
auto marker = static_cast<TRI_df_marker_t const*>(
doc->getDataPtr()); // ONLY IN INDEX, PROTECTED by RUNTIME
// check if the document would be too big
if (static_cast<int64_t>(marker->_size) > _size) {
return TRI_ERROR_ARANGO_DOCUMENT_TOO_LARGE;
}
}
return TRI_ERROR_NO_ERROR;
}
int CapConstraint::remove(triagens::arango::Transaction*, TRI_doc_mptr_t const*,
bool) {
return TRI_ERROR_NO_ERROR;
}
int CapConstraint::postInsert(triagens::arango::Transaction* trx,
TRI_transaction_collection_t* trxCollection,
TRI_doc_mptr_t const*) {
TRI_ASSERT(_count > 0 || _size > 0);
return apply(trx, trxCollection->_collection->_collection, trxCollection);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief initialize the cap constraint
////////////////////////////////////////////////////////////////////////////////
int CapConstraint::initialize(triagens::arango::Transaction* trx) {
TRI_ASSERT(_count > 0 || _size > 0);
TRI_headers_t* headers = _collection->_headersPtr; // ONLY IN INDEX (CAP)
int64_t currentCount = static_cast<int64_t>(headers->count());
int64_t currentSize = headers->size();
if ((_count > 0 && currentCount <= _count) &&
(_size > 0 && currentSize <= _size)) {
// nothing to do
return TRI_ERROR_NO_ERROR;
} else {
TRI_vocbase_t* vocbase = _collection->_vocbase;
TRI_voc_cid_t cid = _collection->_info.id();
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 = apply(&trx, _collection, trxCollection);
res = trx.finish(res);
return res;
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief apply the cap constraint for the collection
////////////////////////////////////////////////////////////////////////////////
int CapConstraint::apply(triagens::arango::Transaction* trx,
TRI_document_collection_t* document,
TRI_transaction_collection_t* trxCollection) {
TRI_headers_t* headers =
document->_headersPtr; // PROTECTED by trx in trxCollection
int64_t currentCount = static_cast<int64_t>(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 ((_count > 0 && currentCount > _count) ||
(_size > 0 && currentSize > _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(trx, 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;
}