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arangodb/arangod/Indexes/PrimaryIndex.cpp

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20 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 "PrimaryIndex.h"
#include "Aql/AstNode.h"
#include "Basics/Exceptions.h"
#include "Basics/StaticStrings.h"
#include "Basics/hashes.h"
#include "Basics/tri-strings.h"
#include "Indexes/SimpleAttributeEqualityMatcher.h"
#include "Utils/Transaction.h"
#include "Utils/TransactionContext.h"
#include "VocBase/document-collection.h"
#include "VocBase/transaction.h"
#include <velocypack/Builder.h>
#include <velocypack/Collection.h>
#include <velocypack/Slice.h>
#include <velocypack/velocypack-aliases.h>
using namespace arangodb;
////////////////////////////////////////////////////////////////////////////////
/// @brief hard-coded vector of the index attributes
/// note that the attribute names must be hard-coded here to avoid an init-order
/// fiasco with StaticStrings::FromString etc.
////////////////////////////////////////////////////////////////////////////////
static std::vector<std::vector<arangodb::basics::AttributeName>> const IndexAttributes
{{arangodb::basics::AttributeName("_id", false)},
{arangodb::basics::AttributeName("_key", false)}};
static inline uint64_t HashKey(void*, uint8_t const* key) {
// can use fast hash-function here, as index values are restricted to strings
return VPackSlice(key).hashString();
}
static inline uint64_t HashElement(void*, TRI_doc_mptr_t const* element) {
return element->getHash();
}
////////////////////////////////////////////////////////////////////////////////
/// @brief determines if a key corresponds to an element
////////////////////////////////////////////////////////////////////////////////
static bool IsEqualKeyElement(void*, uint8_t const* key,
uint64_t const hash,
TRI_doc_mptr_t const* element) {
if (hash != element->getHash()) {
return false;
}
return Transaction::extractKeyFromDocument(VPackSlice(element->vpack())).equals(VPackSlice(key));
}
////////////////////////////////////////////////////////////////////////////////
/// @brief determines if two elements are equal
////////////////////////////////////////////////////////////////////////////////
static bool IsEqualElementElement(void*, TRI_doc_mptr_t const* left,
TRI_doc_mptr_t const* right) {
if (left->getHash() != right->getHash()) {
return false;
}
VPackSlice l = Transaction::extractKeyFromDocument(VPackSlice(left->vpack()));
VPackSlice r = Transaction::extractKeyFromDocument(VPackSlice(right->vpack()));
return l.equals(r);
}
PrimaryIndexIterator::~PrimaryIndexIterator() {
if (_keys != nullptr) {
// return the VPackBuilder to the transaction context
_trx->transactionContextPtr()->returnBuilder(_keys.release());
}
}
TRI_doc_mptr_t* PrimaryIndexIterator::next() {
while (_iterator.valid()) {
auto result = _index->lookupKey(_trx, _iterator.value());
_iterator.next();
if (result != nullptr) {
// found a result
return result;
}
// found no result. now go to next lookup value in _keys
}
return nullptr;
}
void PrimaryIndexIterator::reset() { _iterator.reset(); }
TRI_doc_mptr_t* AllIndexIterator::next() {
if (_reverse) {
return _index->findSequentialReverse(_trx, _position);
}
return _index->findSequential(_trx, _position, _total);
};
void AllIndexIterator::nextBabies(std::vector<TRI_doc_mptr_t*>& buffer, size_t limit) {
size_t atMost = limit;
buffer.clear();
while (atMost > 0) {
auto result = next();
if (result == nullptr) {
return;
}
buffer.emplace_back(result);
--atMost;
}
}
void AllIndexIterator::reset() { _position.reset(); }
TRI_doc_mptr_t* AnyIndexIterator::next() {
return _index->findRandom(_trx, _initial, _position, _step, _total);
}
void AnyIndexIterator::reset() {
_step = 0;
_total = 0;
_position = _initial;
}
PrimaryIndex::PrimaryIndex(TRI_document_collection_t* collection)
: Index(0, collection,
std::vector<std::vector<arangodb::basics::AttributeName>>(
{{{StaticStrings::KeyString, false}}}),
true, false),
_primaryIndex(nullptr) {
uint32_t indexBuckets = 1;
if (collection != nullptr) {
// document is a nullptr in the coordinator case
indexBuckets = collection->_info.indexBuckets();
}
_primaryIndex = new TRI_PrimaryIndex_t(
HashKey, HashElement, IsEqualKeyElement, IsEqualElementElement,
IsEqualElementElement, indexBuckets,
[]() -> std::string { return "primary"; });
}
////////////////////////////////////////////////////////////////////////////////
/// @brief create an index stub with a hard-coded selectivity estimate
/// this is used in the cluster coordinator case
////////////////////////////////////////////////////////////////////////////////
PrimaryIndex::PrimaryIndex(VPackSlice const& slice)
: Index(slice), _primaryIndex(nullptr) {}
PrimaryIndex::~PrimaryIndex() { delete _primaryIndex; }
////////////////////////////////////////////////////////////////////////////////
/// @brief return the number of documents from the index
////////////////////////////////////////////////////////////////////////////////
size_t PrimaryIndex::size() const { return _primaryIndex->size(); }
////////////////////////////////////////////////////////////////////////////////
/// @brief return the memory usage of the index
////////////////////////////////////////////////////////////////////////////////
size_t PrimaryIndex::memory() const { return _primaryIndex->memoryUsage(); }
////////////////////////////////////////////////////////////////////////////////
/// @brief return a VelocyPack representation of the index
////////////////////////////////////////////////////////////////////////////////
void PrimaryIndex::toVelocyPack(VPackBuilder& builder, bool withFigures) const {
Index::toVelocyPack(builder, withFigures);
// hard-coded
builder.add("unique", VPackValue(true));
builder.add("sparse", VPackValue(false));
}
////////////////////////////////////////////////////////////////////////////////
/// @brief return a VelocyPack representation of the index figures
////////////////////////////////////////////////////////////////////////////////
void PrimaryIndex::toVelocyPackFigures(VPackBuilder& builder) const {
Index::toVelocyPackFigures(builder);
_primaryIndex->appendToVelocyPack(builder);
}
int PrimaryIndex::insert(arangodb::Transaction*, TRI_doc_mptr_t const*, bool) {
THROW_ARANGO_EXCEPTION(TRI_ERROR_NOT_IMPLEMENTED);
}
int PrimaryIndex::remove(arangodb::Transaction*, TRI_doc_mptr_t const*, bool) {
THROW_ARANGO_EXCEPTION(TRI_ERROR_NOT_IMPLEMENTED);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief looks up an element given a key
////////////////////////////////////////////////////////////////////////////////
TRI_doc_mptr_t* PrimaryIndex::lookup(arangodb::Transaction* trx,
VPackSlice const& slice) const {
TRI_ASSERT(slice.isArray() && slice.length() == 1);
VPackSlice tmp = slice.at(0);
TRI_ASSERT(tmp.isObject() && tmp.hasKey(StaticStrings::IndexEq));
tmp = tmp.get(StaticStrings::IndexEq);
return _primaryIndex->findByKey(trx, tmp.begin());
}
////////////////////////////////////////////////////////////////////////////////
/// @brief looks up an element given a key
////////////////////////////////////////////////////////////////////////////////
TRI_doc_mptr_t* PrimaryIndex::lookupKey(arangodb::Transaction* trx,
VPackSlice const& key) const {
TRI_ASSERT(key.isString());
return _primaryIndex->findByKey(trx, key.begin());
}
////////////////////////////////////////////////////////////////////////////////
/// @brief a method to iterate over all elements in the index in
/// a sequential order.
/// Returns nullptr if all documents have been returned.
/// Convention: position === 0 indicates a new start.
/// DEPRECATED
////////////////////////////////////////////////////////////////////////////////
TRI_doc_mptr_t* PrimaryIndex::lookupSequential(
arangodb::Transaction* trx, arangodb::basics::BucketPosition& position,
uint64_t& total) {
return _primaryIndex->findSequential(trx, position, total);
}
//////////////////////////////////////////////////////////////////////////////
/// @brief request an iterator over all elements in the index in
/// a sequential order.
//////////////////////////////////////////////////////////////////////////////
IndexIterator* PrimaryIndex::allIterator(arangodb::Transaction* trx,
bool reverse) const {
return new AllIndexIterator(trx, _primaryIndex, reverse);
}
//////////////////////////////////////////////////////////////////////////////
/// @brief request an iterator over all elements in the index in
/// a random order. It is guaranteed that each element is found
/// exactly once unless the collection is modified.
//////////////////////////////////////////////////////////////////////////////
IndexIterator* PrimaryIndex::anyIterator(arangodb::Transaction* trx) const {
return new AnyIndexIterator(trx, _primaryIndex);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief a method to iterate over all elements in the index in
/// reversed sequential order.
/// Returns nullptr if all documents have been returned.
/// Convention: position === UINT64_MAX indicates a new start.
/// DEPRECATED
////////////////////////////////////////////////////////////////////////////////
TRI_doc_mptr_t* PrimaryIndex::lookupSequentialReverse(
arangodb::Transaction* trx, arangodb::basics::BucketPosition& position) {
return _primaryIndex->findSequentialReverse(trx, position);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief adds a key/element to the index
/// returns a status code, and *found will contain a found element (if any)
////////////////////////////////////////////////////////////////////////////////
int PrimaryIndex::insertKey(arangodb::Transaction* trx, TRI_doc_mptr_t* header,
void const** found) {
*found = nullptr;
int res = _primaryIndex->insert(trx, header);
if (res == TRI_ERROR_ARANGO_UNIQUE_CONSTRAINT_VIOLATED) {
*found = _primaryIndex->find(trx, header);
}
return res;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief adds a key/element to the index
/// this is a special, optimized version that receives the target slot index
/// from a previous lookupKey call
////////////////////////////////////////////////////////////////////////////////
int PrimaryIndex::insertKey(arangodb::Transaction* trx, TRI_doc_mptr_t* header,
arangodb::basics::BucketPosition const& position) {
return _primaryIndex->insertAtPosition(trx, header, position);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief removes an key/element from the index
////////////////////////////////////////////////////////////////////////////////
TRI_doc_mptr_t* PrimaryIndex::removeKey(arangodb::Transaction* trx,
VPackSlice const& slice) {
return _primaryIndex->removeByKey(trx, slice.begin());
}
////////////////////////////////////////////////////////////////////////////////
/// @brief resizes the index
////////////////////////////////////////////////////////////////////////////////
int PrimaryIndex::resize(arangodb::Transaction* trx, size_t targetSize) {
return _primaryIndex->resize(trx, targetSize);
}
uint64_t PrimaryIndex::calculateHash(arangodb::Transaction* trx,
VPackSlice const& slice) {
// can use fast hash-function here, as index values are restricted to strings
return slice.hashString();
}
uint64_t PrimaryIndex::calculateHash(arangodb::Transaction* trx,
uint8_t const* key) {
return HashKey(trx, key);
}
void PrimaryIndex::invokeOnAllElements(
std::function<bool(TRI_doc_mptr_t*)> work) {
_primaryIndex->invokeOnAllElements(work);
}
void PrimaryIndex::invokeOnAllElementsForRemoval(
std::function<bool(TRI_doc_mptr_t*)> work) {
_primaryIndex->invokeOnAllElementsForRemoval(work);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief checks whether the index supports the condition
////////////////////////////////////////////////////////////////////////////////
bool PrimaryIndex::supportsFilterCondition(
arangodb::aql::AstNode const* node,
arangodb::aql::Variable const* reference, size_t itemsInIndex,
size_t& estimatedItems, double& estimatedCost) const {
SimpleAttributeEqualityMatcher matcher(IndexAttributes);
return matcher.matchOne(this, node, reference, itemsInIndex, estimatedItems,
estimatedCost);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief creates an IndexIterator for the given Condition
////////////////////////////////////////////////////////////////////////////////
IndexIterator* PrimaryIndex::iteratorForCondition(
arangodb::Transaction* trx, IndexIteratorContext* context,
arangodb::aql::AstNode const* node,
arangodb::aql::Variable const* reference, bool reverse) const {
TRI_ASSERT(node->type == aql::NODE_TYPE_OPERATOR_NARY_AND);
TRI_ASSERT(node->numMembers() == 1);
auto comp = node->getMember(0);
// assume a.b == value
auto attrNode = comp->getMember(0);
auto valNode = comp->getMember(1);
if (attrNode->type != aql::NODE_TYPE_ATTRIBUTE_ACCESS) {
// value == a.b -> flip the two sides
attrNode = comp->getMember(1);
valNode = comp->getMember(0);
}
TRI_ASSERT(attrNode->type == aql::NODE_TYPE_ATTRIBUTE_ACCESS);
if (comp->type == aql::NODE_TYPE_OPERATOR_BINARY_EQ) {
// a.b == value
return createEqIterator(trx, context, attrNode, valNode);
} else if (comp->type == aql::NODE_TYPE_OPERATOR_BINARY_IN) {
// a.b IN values
if (!valNode->isArray()) {
return nullptr;
}
return createInIterator(trx, context, attrNode, valNode);
}
// operator type unsupported
return nullptr;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief creates an IndexIterator for the given slice
////////////////////////////////////////////////////////////////////////////////
IndexIterator* PrimaryIndex::iteratorForSlice(
arangodb::Transaction* trx, IndexIteratorContext* ctxt,
arangodb::velocypack::Slice const searchValues, bool) const {
if (!searchValues.isArray()) {
// Invalid searchValue
return nullptr;
}
// lease builder, but immediately pass it to the unique_ptr so we don't leak
TransactionBuilderLeaser builder(trx);
std::unique_ptr<VPackBuilder> keys(builder.steal());
builder->add(searchValues);
return new PrimaryIndexIterator(trx, this, keys);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief specializes the condition for use with the index
////////////////////////////////////////////////////////////////////////////////
arangodb::aql::AstNode* PrimaryIndex::specializeCondition(
arangodb::aql::AstNode* node,
arangodb::aql::Variable const* reference) const {
SimpleAttributeEqualityMatcher matcher(IndexAttributes);
return matcher.specializeOne(this, node, reference);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief create the iterator, for a single attribute, IN operator
////////////////////////////////////////////////////////////////////////////////
IndexIterator* PrimaryIndex::createInIterator(
arangodb::Transaction* trx, IndexIteratorContext* context,
arangodb::aql::AstNode const* attrNode,
arangodb::aql::AstNode const* valNode) const {
// _key or _id?
bool const isId = (attrNode->stringEquals(StaticStrings::IdString));
TRI_ASSERT(valNode->isArray());
// lease builder, but immediately pass it to the unique_ptr so we don't leak
TransactionBuilderLeaser builder(trx);
std::unique_ptr<VPackBuilder> keys(builder.steal());
keys->openArray();
size_t const n = valNode->numMembers();
// only leave the valid elements
for (size_t i = 0; i < n; ++i) {
handleValNode(context, keys.get(), valNode->getMemberUnchecked(i), isId);
TRI_IF_FAILURE("PrimaryIndex::iteratorValNodes") {
THROW_ARANGO_EXCEPTION(TRI_ERROR_DEBUG);
}
}
TRI_IF_FAILURE("PrimaryIndex::noIterator") {
THROW_ARANGO_EXCEPTION(TRI_ERROR_DEBUG);
}
keys->close();
return new PrimaryIndexIterator(trx, this, keys);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief create the iterator, for a single attribute, EQ operator
////////////////////////////////////////////////////////////////////////////////
IndexIterator* PrimaryIndex::createEqIterator(
arangodb::Transaction* trx, IndexIteratorContext* context,
arangodb::aql::AstNode const* attrNode,
arangodb::aql::AstNode const* valNode) const {
// _key or _id?
bool const isId = (attrNode->stringEquals(StaticStrings::IdString));
// lease builder, but immediately pass it to the unique_ptr so we don't leak
TransactionBuilderLeaser builder(trx);
std::unique_ptr<VPackBuilder> keys(builder.steal());
keys->openArray();
// handle the sole element
handleValNode(context, keys.get(), valNode, isId);
TRI_IF_FAILURE("PrimaryIndex::noIterator") {
THROW_ARANGO_EXCEPTION(TRI_ERROR_DEBUG);
}
keys->close();
return new PrimaryIndexIterator(trx, this, keys);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief add a single value node to the iterator's keys
////////////////////////////////////////////////////////////////////////////////
void PrimaryIndex::handleValNode(IndexIteratorContext* context,
VPackBuilder* keys,
arangodb::aql::AstNode const* valNode,
bool isId) const {
if (!valNode->isStringValue() || valNode->getStringLength() == 0) {
return;
}
if (isId) {
// lookup by _id. now validate if the lookup is performed for the
// correct collection (i.e. _collection)
TRI_voc_cid_t cid;
char const* key;
size_t outLength;
int res = context->resolveId(valNode->getStringValue(), valNode->getStringLength(), cid, key, outLength);
if (res != TRI_ERROR_NO_ERROR) {
return;
}
TRI_ASSERT(cid != 0);
TRI_ASSERT(key != nullptr);
if (!context->isCluster() && cid != _collection->_info.id()) {
// only continue lookup if the id value is syntactically correct and
// refers to "our" collection, using local collection id
return;
}
if (context->isCluster() && cid != _collection->_info.planId()) {
// only continue lookup if the id value is syntactically correct and
// refers to "our" collection, using cluster collection id
return;
}
// use _key value from _id
keys->add(VPackValuePair(key, outLength, VPackValueType::String));
} else {
keys->add(VPackValuePair(valNode->getStringValue(), valNode->getStringLength(), VPackValueType::String));
}
}