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arangodb/arangod/Indexes/SkiplistIndex2.cpp

388 lines
15 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// @brief skiplist index
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2014 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
/// @author Copyright 2014, ArangoDB GmbH, Cologne, Germany
/// @author Copyright 2011-2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#include "SkiplistIndex2.h"
#include "Basics/logging.h"
#include "VocBase/document-collection.h"
#include "VocBase/transaction.h"
#include "VocBase/voc-shaper.h"
using namespace triagens::arango;
// -----------------------------------------------------------------------------
// --SECTION-- private functions
// -----------------------------------------------------------------------------
static int FillLookupOperator (TRI_index_operator_t* slOperator,
TRI_document_collection_t* document) {
if (slOperator == nullptr) {
return TRI_ERROR_INTERNAL;
}
switch (slOperator->_type) {
case TRI_AND_INDEX_OPERATOR:
case TRI_NOT_INDEX_OPERATOR:
case TRI_OR_INDEX_OPERATOR: {
TRI_logical_index_operator_t* logicalOperator = (TRI_logical_index_operator_t*) slOperator;
int res = FillLookupOperator(logicalOperator->_left, document);
if (res == TRI_ERROR_NO_ERROR) {
res = FillLookupOperator(logicalOperator->_right, document);
}
if (res != TRI_ERROR_NO_ERROR) {
return res;
}
break;
}
case TRI_EQ_INDEX_OPERATOR:
case TRI_GE_INDEX_OPERATOR:
case TRI_GT_INDEX_OPERATOR:
case TRI_NE_INDEX_OPERATOR:
case TRI_LE_INDEX_OPERATOR:
case TRI_LT_INDEX_OPERATOR: {
TRI_relation_index_operator_t* relationOperator = (TRI_relation_index_operator_t*) slOperator;
relationOperator->_numFields = TRI_LengthVector(&relationOperator->_parameters->_value._objects);
relationOperator->_fields = static_cast<TRI_shaped_json_t*>(TRI_Allocate(TRI_UNKNOWN_MEM_ZONE, sizeof(TRI_shaped_json_t) * relationOperator->_numFields, false));
if (relationOperator->_fields != nullptr) {
for (size_t j = 0; j < relationOperator->_numFields; ++j) {
TRI_json_t const* jsonObject = static_cast<TRI_json_t* const>(TRI_AtVector(&(relationOperator->_parameters->_value._objects), j));
// find out if the search value is a list or an array
if ((TRI_IsArrayJson(jsonObject) || TRI_IsObjectJson(jsonObject)) &&
slOperator->_type != TRI_EQ_INDEX_OPERATOR) {
// non-equality operator used on list or array data type, this is disallowed
// because we need to shape these objects first. however, at this place (index lookup)
// we never want to create new shapes so we will have a problem if we cannot find an
// existing shape for the search value. in this case we would need to raise an error
// but then the query results would depend on the state of the shaper and if it had
// seen previous such objects
// we still allow looking for list or array values using equality. this is safe.
TRI_Free(TRI_UNKNOWN_MEM_ZONE, relationOperator->_fields);
relationOperator->_fields = nullptr;
return TRI_ERROR_BAD_PARAMETER;
}
// now shape the search object (but never create any new shapes)
TRI_shaped_json_t* shapedObject = TRI_ShapedJsonJson(document->getShaper(), jsonObject, false); // ONLY IN INDEX, PROTECTED by RUNTIME
if (shapedObject != nullptr) {
// found existing shape
relationOperator->_fields[j] = *shapedObject; // shallow copy here is ok
TRI_Free(TRI_UNKNOWN_MEM_ZONE, shapedObject); // don't require storage anymore
}
else {
// shape not found
TRI_Free(TRI_UNKNOWN_MEM_ZONE, relationOperator->_fields);
relationOperator->_fields = nullptr;
return TRI_RESULT_ELEMENT_NOT_FOUND;
}
}
}
else {
relationOperator->_numFields = 0; // out of memory?
}
break;
}
}
return TRI_ERROR_NO_ERROR;
}
// -----------------------------------------------------------------------------
// --SECTION-- class SkiplistIndex
// -----------------------------------------------------------------------------
// -----------------------------------------------------------------------------
// --SECTION-- constructors and destructors
// -----------------------------------------------------------------------------
SkiplistIndex2::SkiplistIndex2 (TRI_idx_iid_t iid,
TRI_document_collection_t* collection,
std::vector<std::string> const& fields,
std::vector<TRI_shape_pid_t> const& paths,
bool unique,
bool sparse)
: Index(iid, collection, fields),
_paths(paths),
_skiplistIndex(nullptr),
_unique(unique),
_sparse(sparse) {
TRI_ASSERT(iid != 0);
_skiplistIndex = SkiplistIndex_new(collection,
paths.size(),
unique);
}
SkiplistIndex2::~SkiplistIndex2 () {
if (_skiplistIndex != nullptr) {
SkiplistIndex_free(_skiplistIndex);
}
}
// -----------------------------------------------------------------------------
// --SECTION-- public methods
// -----------------------------------------------------------------------------
size_t SkiplistIndex2::memory () const {
return SkiplistIndex_memoryUsage(_skiplistIndex);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief return a JSON representation of the index
////////////////////////////////////////////////////////////////////////////////
triagens::basics::Json SkiplistIndex2::toJson (TRI_memory_zone_t* zone) const {
auto json = Index::toJson(zone);
json("unique", triagens::basics::Json(zone, _unique))
("sparse", triagens::basics::Json(zone, _sparse));
return json;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief inserts a document into a skiplist index
////////////////////////////////////////////////////////////////////////////////
int SkiplistIndex2::insert (TRI_doc_mptr_t const* doc,
bool) {
auto skiplistElement = static_cast<TRI_skiplist_index_element_t*>(TRI_Allocate(TRI_UNKNOWN_MEM_ZONE, SkiplistIndex_ElementSize(_skiplistIndex), false));
if (skiplistElement == nullptr) {
return TRI_ERROR_OUT_OF_MEMORY;
}
int res = fillElement(skiplistElement, doc);
// ...........................................................................
// most likely the cause of this error is that the index is sparse
// and not all attributes the index needs are set -- so the document
// is ignored. So not really an error at all. Note that this does
// not happen in a non-sparse skiplist index, in which empty
// attributes are always treated as if they were bound to null, so
// TRI_ERROR_ARANGO_INDEX_DOCUMENT_ATTRIBUTE_MISSING cannot happen at
// all.
// ...........................................................................
// .........................................................................
// It may happen that the document does not have the necessary
// attributes to be included within the hash index, in this case do
// not report back an error.
// .........................................................................
if (res == TRI_ERROR_ARANGO_INDEX_DOCUMENT_ATTRIBUTE_MISSING) {
if (_sparse) {
TRI_Free(TRI_UNKNOWN_MEM_ZONE, skiplistElement);
return TRI_ERROR_NO_ERROR;
}
res = TRI_ERROR_NO_ERROR;
}
if (res != TRI_ERROR_NO_ERROR) {
TRI_Free(TRI_UNKNOWN_MEM_ZONE, skiplistElement);
return res;
}
// insert into the index. the memory for the element will be owned or freed
// by the index
return SkiplistIndex_insert(_skiplistIndex, skiplistElement);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief removes a document from a skiplist index
////////////////////////////////////////////////////////////////////////////////
int SkiplistIndex2::remove (TRI_doc_mptr_t const* doc,
bool) {
auto skiplistElement = static_cast<TRI_skiplist_index_element_t*>(TRI_Allocate(TRI_UNKNOWN_MEM_ZONE, SkiplistIndex_ElementSize(_skiplistIndex), false));
if (skiplistElement == nullptr) {
return TRI_ERROR_OUT_OF_MEMORY;
}
int res = fillElement(skiplistElement, doc);
// ..........................................................................
// Error returned generally implies that the document never was part of the
// skiplist index
// ..........................................................................
if (res == TRI_ERROR_ARANGO_INDEX_DOCUMENT_ATTRIBUTE_MISSING) {
if (_sparse) {
TRI_Free(TRI_UNKNOWN_MEM_ZONE, skiplistElement);
return TRI_ERROR_NO_ERROR;
}
res = TRI_ERROR_NO_ERROR;
}
if (res != TRI_ERROR_NO_ERROR) {
TRI_Free(TRI_UNKNOWN_MEM_ZONE, skiplistElement);
return res;
}
// attempt the removal for skiplist indexes
// ownership for the index element is transferred to the index
return SkiplistIndex_remove(_skiplistIndex, skiplistElement);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief attempts to locate an entry in the skip list index
///
/// Note: this function will not destroy the passed slOperator before it returns
/// Warning: who ever calls this function is responsible for destroying
/// the TRI_index_operator_t* and the TRI_skiplist_iterator_t* results
////////////////////////////////////////////////////////////////////////////////
TRI_skiplist_iterator_t* SkiplistIndex2::lookup (TRI_index_operator_t* slOperator,
bool reverse) {
if (slOperator == nullptr) {
return nullptr;
}
// .........................................................................
// fill the relation operators which may be embedded in the slOperator with
// additional information. Recall the slOperator is what information was
// received from a user for query the skiplist.
// .........................................................................
int res = FillLookupOperator(slOperator, _collection);
if (res != TRI_ERROR_NO_ERROR) {
TRI_set_errno(res);
return nullptr;
}
return SkiplistIndex_find(_skiplistIndex,
slOperator,
reverse);
}
// -----------------------------------------------------------------------------
// --SECTION-- private methods
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief helper for skiplist methods
////////////////////////////////////////////////////////////////////////////////
int SkiplistIndex2::fillElement(TRI_skiplist_index_element_t* skiplistElement,
TRI_doc_mptr_t const* document) {
// ..........................................................................
// Assign the document to the SkiplistIndexElement structure so that it can
// be retrieved later.
// ..........................................................................
TRI_ASSERT(document != nullptr);
TRI_ASSERT_EXPENSIVE(document->getDataPtr() != nullptr); // ONLY IN INDEX, PROTECTED by RUNTIME
TRI_shaped_json_t shapedJson;
TRI_EXTRACT_SHAPED_JSON_MARKER(shapedJson, document->getDataPtr()); // ONLY IN INDEX, PROTECTED by RUNTIME
if (shapedJson._sid == TRI_SHAPE_ILLEGAL) {
LOG_WARNING("encountered invalid marker with shape id 0");
return TRI_ERROR_INTERNAL;
}
int res = TRI_ERROR_NO_ERROR;
skiplistElement->_document = const_cast<TRI_doc_mptr_t*>(document);
char const* ptr = skiplistElement->_document->getShapedJsonPtr(); // ONLY IN INDEX, PROTECTED by RUNTIME
auto subObjects = SkiplistIndex_Subobjects(skiplistElement);
size_t const n = _paths.size();
for (size_t j = 0; j < n; ++j) {
TRI_shape_pid_t shape = _paths[j];
// ..........................................................................
// Determine if document has that particular shape
// ..........................................................................
TRI_shape_access_t const* acc = TRI_FindAccessorVocShaper(_collection->getShaper(), shapedJson._sid, shape); // ONLY IN INDEX, PROTECTED by RUNTIME
if (acc == nullptr || acc->_resultSid == TRI_SHAPE_ILLEGAL) {
// OK, the document does not contain the attributed needed by
// the index, are we sparse?
subObjects[j]._sid = BasicShapes::TRI_SHAPE_SID_NULL;
res = TRI_ERROR_ARANGO_INDEX_DOCUMENT_ATTRIBUTE_MISSING;
if (_sparse) {
// no need to continue
return res;
}
continue;
}
// ..........................................................................
// Extract the field
// ..........................................................................
TRI_shaped_json_t shapedObject;
if (! TRI_ExecuteShapeAccessor(acc, &shapedJson, &shapedObject)) {
return TRI_ERROR_INTERNAL;
}
if (shapedObject._sid == BasicShapes::TRI_SHAPE_SID_NULL) {
res = TRI_ERROR_ARANGO_INDEX_DOCUMENT_ATTRIBUTE_MISSING;
if (_sparse) {
// no need to continue
return res;
}
}
// .........................................................................
// Store the field
// .........................................................................
TRI_FillShapedSub(&subObjects[j], &shapedObject, ptr);
}
return res;
}
// -----------------------------------------------------------------------------
// --SECTION-- END-OF-FILE
// -----------------------------------------------------------------------------
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// outline-regexp: "/// @brief\\|/// {@inheritDoc}\\|/// @page\\|// --SECTION--\\|/// @\\}"
// End: