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Started templatefying hash-array to AssocUnique

This commit is contained in:
Michael Hackstein 2015-08-24 14:16:45 +02:00
parent 2dd0f7cf7f
commit 80e1f6decc
2 changed files with 415 additions and 476 deletions

View File

@ -32,7 +32,6 @@
#include "hash-array.h"
#include "Basics/fasthash.h"
#include "Basics/logging.h"
#include "Indexes/HashIndex.h"
#include "VocBase/document-collection.h"
#include "VocBase/VocShaper.h"
@ -111,277 +110,6 @@ uint64_t TRI_hash_array_t::hashElement (TRI_index_element_t const* element) cons
return hash;
}
// -----------------------------------------------------------------------------
// --SECTION-- HASH ARRAY
// -----------------------------------------------------------------------------
// -----------------------------------------------------------------------------
// --SECTION-- private functions
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief resizes the array
////////////////////////////////////////////////////////////////////////////////
int TRI_hash_array_t::resizeInternal (triagens::arango::HashIndex* hashIndex,
Bucket& b,
uint64_t targetSize,
bool allowShrink) {
if (b._nrAlloc >= targetSize && ! allowShrink) {
return TRI_ERROR_NO_ERROR;
}
// only log performance infos for indexes with more than this number of entries
static uint64_t const NotificationSizeThreshold = 131072;
double start = TRI_microtime();
if (targetSize > NotificationSizeThreshold) {
LOG_ACTION("index-resize %s, target size: %llu",
hashIndex->context().c_str(),
(unsigned long long) targetSize);
}
TRI_index_element_t** oldTable = b._table;
uint64_t oldAlloc = b._nrAlloc;
TRI_ASSERT(targetSize > 0);
try {
b._table = new TRI_index_element_t* [targetSize];
for (uint64_t i = 0; i < targetSize; i++) {
b._table[i] = nullptr;
}
}
catch (...) {
return TRI_ERROR_OUT_OF_MEMORY;
}
b._nrAlloc = targetSize;
if (b._nrUsed > 0) {
uint64_t const n = b._nrAlloc;
for (uint64_t j = 0; j < oldAlloc; j++) {
TRI_index_element_t* element = oldTable[j];
if (element != nullptr) {
uint64_t i, k;
i = k = hashElement(element) % n;
for (; i < n && b._table[i] != nullptr; ++i);
if (i == n) {
for (i = 0; i < k && b._table[i] != nullptr; ++i);
}
b._table[i] = element;
}
}
}
delete [] oldTable;
LOG_TIMER((TRI_microtime() - start),
"index-resize %s, target size: %llu",
hashIndex->context().c_str(),
(unsigned long long) targetSize);
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief triggers a resize if necessary
////////////////////////////////////////////////////////////////////////////////
bool TRI_hash_array_t::checkResize (triagens::arango::HashIndex* hashIndex,
Bucket& b) {
if (2 * b._nrAlloc < 3 * b._nrUsed) {
int res = resizeInternal(hashIndex, b, 2 * b._nrAlloc + 1, false);
if (res != TRI_ERROR_NO_ERROR) {
return false;
}
}
return true;
}
// -----------------------------------------------------------------------------
// --SECTION-- public functions
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief get the hash array's memory usage
////////////////////////////////////////////////////////////////////////////////
size_t TRI_hash_array_t::memoryUsage () {
size_t sum = 0;
for (auto& b : _buckets) {
sum += (size_t) (b._nrAlloc * sizeof(TRI_index_element_t*));
}
return sum;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief resizes the hash table
////////////////////////////////////////////////////////////////////////////////
int TRI_hash_array_t::resize (triagens::arango::HashIndex* hashIndex,
size_t size) {
int res = TRI_ERROR_NO_ERROR;
for (auto& b : _buckets) {
res = resizeInternal(hashIndex, b,
(uint64_t) (3 * size / 2 + 1) / _buckets.size(),
false);
if (res != TRI_ERROR_NO_ERROR) {
return res;
}
}
return res;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief finds an element given a key, return NULL if not found
////////////////////////////////////////////////////////////////////////////////
TRI_index_element_t* TRI_hash_array_t::findByKey (TRI_index_search_value_t* key) const {
uint64_t i = hashKey(key);
Bucket const& b = _buckets[i & _bucketsMask];
uint64_t const n = b._nrAlloc;
i = i % n;
uint64_t k = i;
for (; i < n && b._table[i] != nullptr &&
! isEqualKeyElement(key, b._table[i]); ++i);
if (i == n) {
for (i = 0; i < k && b._table[i] != nullptr &&
! isEqualKeyElement(key, b._table[i]); ++i);
}
// ...........................................................................
// return whatever we found, this is nullptr if the thing was not found
// and otherwise a valid pointer
// ...........................................................................
return b._table[i];
}
////////////////////////////////////////////////////////////////////////////////
/// @brief adds an key/element to the array
///
/// This function claims the owenship of the sub-objects in the inserted
/// element.
////////////////////////////////////////////////////////////////////////////////
int TRI_hash_array_t::insert (triagens::arango::HashIndex* hashIndex,
TRI_index_search_value_t const* key,
TRI_index_element_t const* element,
bool isRollback) {
// ...........................................................................
// we are adding and the table is more than half full, extend it
// ...........................................................................
uint64_t i = hashKey(key);
Bucket& b = _buckets[i & _bucketsMask];
if (! checkResize(hashIndex, b)) {
return TRI_ERROR_OUT_OF_MEMORY;
}
uint64_t const n = b._nrAlloc;
i = i % n;
uint64_t k = i;
for (; i < n && b._table[i] != nullptr &&
! isEqualKeyElement(key, b._table[i]); ++i);
if (i == n) {
for (i = 0; i < k && b._table[i] != nullptr &&
! isEqualKeyElement(key, b._table[i]); ++i);
}
TRI_index_element_t* arrayElement = b._table[i];
// ...........................................................................
// if we found an element, return
// ...........................................................................
if (arrayElement != nullptr) {
return TRI_ERROR_ARANGO_UNIQUE_CONSTRAINT_VIOLATED;
}
b._table[i] = const_cast<TRI_index_element_t*>(element);
TRI_ASSERT(b._table[i] != nullptr && b._table[i]->document() != nullptr);
b._nrUsed++;
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief removes an element from the array
////////////////////////////////////////////////////////////////////////////////
TRI_index_element_t* TRI_hash_array_t::remove (
triagens::arango::HashIndex* hashIndex,
TRI_index_element_t* element) {
uint64_t i = hashElement(element);
Bucket& b = _buckets[i & _bucketsMask];
uint64_t const n = b._nrAlloc;
i = i % n;
uint64_t k = i;
for (; i < n && b._table[i] != nullptr &&
element->document() != b._table[i]->document(); ++i);
if (i == n) {
for (i = 0; i < k && b._table[i] != nullptr &&
element->document() != b._table[i]->document(); ++i);
}
TRI_index_element_t* old = b._table[i];
// ...........................................................................
// if we did not find such an item return error code
// ...........................................................................
if (old == nullptr) {
return old;
}
// ...........................................................................
// remove item - destroy any internal memory associated with the
// element structure
// ...........................................................................
b._table[i] = nullptr;
b._nrUsed--;
// ...........................................................................
// and now check the following places for items to move closer together
// so that there are no gaps in the array
// ...........................................................................
k = TRI_IncModU64(i, n);
while (b._table[k] != nullptr) {
uint64_t j = hashElement(b._table[k]) % n;
if ((i < k && ! (i < j && j <= k)) || (k < i && ! (i < j || j <= k))) {
b._table[i] = b._table[k];
b._table[k] = nullptr;
i = k;
}
k = TRI_IncModU64(k, n);
}
if (b._nrUsed == 0) {
resizeInternal (hashIndex, b, initialSize(), true);
}
return old;
}
// -----------------------------------------------------------------------------
// --SECTION-- END-OF-FILE
// -----------------------------------------------------------------------------

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@ -32,235 +32,446 @@
#define ARANGODB_HASH_INDEX_HASH__ARRAY_H 1
#include "Basics/Common.h"
#include "Indexes/Index.h"
// -----------------------------------------------------------------------------
// --SECTION-- forward declarations
// -----------------------------------------------------------------------------
#include "Basics/logging.h"
namespace triagens {
namespace arango {
class HashIndex;
}
}
namespace basics {
// -----------------------------------------------------------------------------
// --SECTION-- UNIQUE ASSOCIATIVE POINTERS
// -----------------------------------------------------------------------------
// -----------------------------------------------------------------------------
// --SECTION-- TRI_hash_array_t
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief associative array
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
/// @brief associative array
////////////////////////////////////////////////////////////////////////////////
template <class Key, class Element>
class AssocUnique {
class TRI_hash_array_t {
size_t _numFields; // the number of fields indexes
public:
struct Bucket {
typedef std::function<uint64_t(Key const*)> HashKeyFuncType;
typedef std::function<uint64_t(Element const*, bool)> HashElementFuncType;
typedef std::function<bool(Key const*, Element const*)>
IsEqualKeyElementFuncType;
typedef std::function<void(Element*)> CallbackElementFuncType;
uint64_t _nrAlloc; // the size of the table
uint64_t _nrUsed; // the number of used entries
private:
size_t _numFields; // the number of fields indexes
TRI_index_element_t** _table; // the table itself, aligned to a cache line boundary
};
struct Bucket {
std::vector<Bucket> _buckets;
size_t _bucketsMask;
uint64_t _nrAlloc; // the size of the table
uint64_t _nrUsed; // the number of used entries
// -----------------------------------------------------------------------------
// --SECTION-- constructors and destructors
// -----------------------------------------------------------------------------
Element** _table; // the table itself, aligned to a cache line boundary
};
////////////////////////////////////////////////////////////////////////////////
/// @brief constructor
////////////////////////////////////////////////////////////////////////////////
std::vector<Bucket> _buckets;
size_t _bucketsMask;
public:
TRI_hash_array_t (size_t numFields, size_t numberBuckets = 1)
: _numFields(numFields) {
HashKeyFuncType const _hashKey;
HashElementFuncType const _hashElement;
IsEqualKeyElementFuncType const _isEqualKeyElement;
// Make the number of buckets a power of two:
size_t ex = 0;
size_t nr = 1;
numberBuckets >>= 1;
while (numberBuckets > 0) {
ex += 1;
numberBuckets >>= 1;
nr <<= 1;
}
numberBuckets = nr;
_bucketsMask = nr - 1;
std::function<std::string()> _contextCallback;
try {
for (size_t j = 0; j < numberBuckets; j++) {
_buckets.emplace_back();
Bucket& b = _buckets.back();
b._nrAlloc = initialSize();
b._table = nullptr;
// -----------------------------------------------------------------------------
// --SECTION-- constructors and destructors
// -----------------------------------------------------------------------------
// may fail...
b._table = new TRI_index_element_t* [b._nrAlloc];
////////////////////////////////////////////////////////////////////////////////
/// @brief constructor
////////////////////////////////////////////////////////////////////////////////
for (uint64_t i = 0; i < b._nrAlloc; i++) {
b._table[i] = nullptr;
}
}
}
catch (...) {
for (auto& b : _buckets) {
delete [] b._table;
b._table = nullptr;
b._nrAlloc = 0;
}
throw;
}
}
public:
AssocUnique (HashKeyFuncType hashKey,
HashElementFuncType hashElement,
IsEqualKeyElementFuncType isEqualKeyElement,
size_t numFields,
size_t numberBuckets = 1,
std::function<std::string()> contextCallback = [] () -> std::string { return ""; }) :
_numFields(numFields)
_hashKey(hashKey),
_hashElement(hashElement),
_isEqualKeyElement(isEqualKeyElement),
_contextCallback(contextCallback) {
////////////////////////////////////////////////////////////////////////////////
/// @brief destructor
////////////////////////////////////////////////////////////////////////////////
// Make the number of buckets a power of two:
size_t ex = 0;
size_t nr = 1;
numberBuckets >>= 1;
while (numberBuckets > 0) {
ex += 1;
numberBuckets >>= 1;
nr <<= 1;
}
numberBuckets = nr;
_bucketsMask = nr - 1;
~TRI_hash_array_t () {
for (auto& b : _buckets) {
delete [] b._table;
b._table = nullptr;
b._nrAlloc = 0;
}
}
try {
for (size_t j = 0; j < numberBuckets; j++) {
_buckets.emplace_back();
Bucket& b = _buckets.back();
b._nrAlloc = initialSize();
b._table = nullptr;
////////////////////////////////////////////////////////////////////////////////
/// @brief adhere to the rule of five
////////////////////////////////////////////////////////////////////////////////
// may fail...
b._table = new Element* [b._nrAlloc];
TRI_hash_array_t (TRI_hash_array_t const&) = delete; // copy constructor
TRI_hash_array_t (TRI_hash_array_t&&) = delete; // move constructor
TRI_hash_array_t& operator= (TRI_hash_array_t const&) = delete; // op =
TRI_hash_array_t& operator= (TRI_hash_array_t&&) = delete; // op =
for (uint64_t i = 0; i < b._nrAlloc; i++) {
b._table[i] = nullptr;
}
}
}
catch (...) {
for (auto& b : _buckets) {
delete [] b._table;
b._table = nullptr;
b._nrAlloc = 0;
}
throw;
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief a type for a generic callback to run over all elements
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
/// @brief destructor
////////////////////////////////////////////////////////////////////////////////
typedef std::function<void(TRI_index_element_t*)> CallbackElementFuncType;
////////////////////////////////////////////////////////////////////////////////
/// @brief initial preallocation size of the hash table when the table is
/// first created
/// setting this to a high value will waste memory but reduce the number of
/// reallocations/repositionings necessary when the table grows
////////////////////////////////////////////////////////////////////////////////
private:
static uint64_t initialSize () {
return 251;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief determines if a key corresponds to an element
////////////////////////////////////////////////////////////////////////////////
bool isEqualKeyElement (TRI_index_search_value_t const* left,
TRI_index_element_t const* right) const;
////////////////////////////////////////////////////////////////////////////////
/// @brief given a key generates a hash integer
////////////////////////////////////////////////////////////////////////////////
uint64_t hashKey (TRI_index_search_value_t const* key) const;
////////////////////////////////////////////////////////////////////////////////
/// @brief given an element generates a hash integer
////////////////////////////////////////////////////////////////////////////////
uint64_t hashElement (TRI_index_element_t const* element) const;
////////////////////////////////////////////////////////////////////////////////
/// @brief resize the hash array
////////////////////////////////////////////////////////////////////////////////
int resizeInternal (triagens::arango::HashIndex* hashIndex,
Bucket& b,
uint64_t targetSize,
bool allowShrink);
////////////////////////////////////////////////////////////////////////////////
/// @brief check a resize of the hash array
////////////////////////////////////////////////////////////////////////////////
bool checkResize (triagens::arango::HashIndex* hashIndex,
Bucket& b);
// -----------------------------------------------------------------------------
// --SECTION-- public functions
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief get the hash array's memory usage
////////////////////////////////////////////////////////////////////////////////
public:
size_t memoryUsage ();
////////////////////////////////////////////////////////////////////////////////
/// @brief get the number of elements in the hash
////////////////////////////////////////////////////////////////////////////////
size_t size () {
size_t sum = 0;
for (auto& b : _buckets) {
sum += static_cast<size_t>(b._nrUsed);
}
return sum;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief resizes the hash table
////////////////////////////////////////////////////////////////////////////////
int resize (triagens::arango::HashIndex*, size_t);
////////////////////////////////////////////////////////////////////////////////
/// @brief finds an element given a key, returns NULL if not found
////////////////////////////////////////////////////////////////////////////////
TRI_index_element_t* findByKey (TRI_index_search_value_t* key) const;
////////////////////////////////////////////////////////////////////////////////
/// @brief adds an key/element to the array
////////////////////////////////////////////////////////////////////////////////
int insert (triagens::arango::HashIndex*,
TRI_index_search_value_t const* key,
TRI_index_element_t const* element,
bool isRollback);
////////////////////////////////////////////////////////////////////////////////
/// @brief removes an element from the array, returns nullptr if the element
/// was not found and the old value, if it was successfully removed
////////////////////////////////////////////////////////////////////////////////
TRI_index_element_t* remove (triagens::arango::HashIndex*,
TRI_index_element_t* element);
////////////////////////////////////////////////////////////////////////////////
/// @brief a method to iterate over all elements in the hash
////////////////////////////////////////////////////////////////////////////////
void invokeOnAllElements (CallbackElementFuncType callback) {
for (auto& b : _buckets) {
if (b._table != nullptr) {
for (size_t i = 0; i < b._nrAlloc; ++i) {
if (b._table[i] != nullptr) {
callback(b._table[i]);
~AssocUnique () {
for (auto& b : _buckets) {
delete [] b._table;
b._table = nullptr;
b._nrAlloc = 0;
}
}
}
}
}
};
////////////////////////////////////////////////////////////////////////////////
/// @brief adhere to the rule of five
////////////////////////////////////////////////////////////////////////////////
AssocUnique (AssocUnique const&) = delete; // copy constructor
AssocUnique (AssocUnique&&) = delete; // move constructor
AssocUnique& operator= (AssocUnique const&) = delete; // op =
AssocUnique& operator= (AssocUnique&&) = delete; // op =
////////////////////////////////////////////////////////////////////////////////
/// @brief initial preallocation size of the hash table when the table is
/// first created
/// setting this to a high value will waste memory but reduce the number of
/// reallocations/repositionings necessary when the table grows
////////////////////////////////////////////////////////////////////////////////
private:
static uint64_t initialSize () {
return 251;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief determines if a key corresponds to an element
////////////////////////////////////////////////////////////////////////////////
bool isEqualKeyElement (Key const* left,
Element const* right) const;
////////////////////////////////////////////////////////////////////////////////
/// @brief given a key generates a hash integer
////////////////////////////////////////////////////////////////////////////////
uint64_t hashKey (Key const* key) const;
////////////////////////////////////////////////////////////////////////////////
/// @brief given an element generates a hash integer
////////////////////////////////////////////////////////////////////////////////
uint64_t hashElement (Element const* element) const;
////////////////////////////////////////////////////////////////////////////////
/// @brief resizes the array
////////////////////////////////////////////////////////////////////////////////
void resizeInternal (Bucket& b,
uint64_t targetSize,
bool allowShrink) {
if (b._nrAlloc >= targetSize && ! allowShrink) {
return;
}
// only log performance infos for indexes with more than this number of entries
static uint64_t const NotificationSizeThreshold = 131072;
double start = TRI_microtime();
if (targetSize > NotificationSizeThreshold) {
LOG_ACTION("index-resize %s, target size: %llu",
_contextCallback().c_str(),
(unsigned long long) targetSize);
}
Element** oldTable = b._table;
uint64_t oldAlloc = b._nrAlloc;
TRI_ASSERT(targetSize > 0);
// This might throw, is catched outside
b._table = new Element* [targetSize];
for (uint64_t i = 0; i < targetSize; i++) {
b._table[i] = nullptr;
}
b._nrAlloc = targetSize;
if (b._nrUsed > 0) {
uint64_t const n = b._nrAlloc;
for (uint64_t j = 0; j < oldAlloc; j++) {
Element* element = oldTable[j];
if (element != nullptr) {
uint64_t i, k;
i = k = _hashElement(element) % n;
for (; i < n && b._table[i] != nullptr; ++i);
if (i == n) {
for (i = 0; i < k && b._table[i] != nullptr; ++i);
}
b._table[i] = element;
}
}
}
delete [] oldTable;
LOG_TIMER((TRI_microtime() - start),
"index-resize %s, target size: %llu",
_contextCallback().c_str(),
(unsigned long long) targetSize);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief check a resize of the hash array
////////////////////////////////////////////////////////////////////////////////
bool checkResize (Bucket& b) {
if (2 * b._nrAlloc < 3 * b._nrUsed) {
try {
resizeInternal(b, 2 * b._nrAlloc + 1, false);
}
catch (...) {
return false;
}
}
return true;
}
// -----------------------------------------------------------------------------
// --SECTION-- public functions
// -----------------------------------------------------------------------------
public:
////////////////////////////////////////////////////////////////////////////////
/// @brief get the hash array's memory usage
////////////////////////////////////////////////////////////////////////////////
size_t memoryUsage () {
size_t sum = 0;
for (auto& b : _buckets) {
sum += (size_t) (b._nrAlloc * sizeof(TRI_index_element_t*));
}
return sum;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief get the number of elements in the hash
////////////////////////////////////////////////////////////////////////////////
size_t size () {
size_t sum = 0;
for (auto& b : _buckets) {
sum += static_cast<size_t>(b._nrUsed);
}
return sum;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief resizes the hash table
////////////////////////////////////////////////////////////////////////////////
int resize (size_t size) {
for (auto& b : _buckets) {
try {
resizeInternal(b,
(uint64_t) (3 * size / 2 + 1) / _buckets.size(),
false);
}
catch (...) {
return TRI_ERROR_OUT_OF_MEMORY;
}
}
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief finds an element given a key, returns NULL if not found
////////////////////////////////////////////////////////////////////////////////
Element* findByKey (Key* key) const {
uint64_t i = _hashKey(key);
Bucket const& b = _buckets[i & _bucketsMask];
uint64_t const n = b._nrAlloc;
i = i % n;
uint64_t k = i;
for (; i < n && b._table[i] != nullptr &&
! _isEqualKeyElement(key, b._table[i]); ++i);
if (i == n) {
for (i = 0; i < k && b._table[i] != nullptr &&
! _isEqualKeyElement(key, b._table[i]); ++i);
}
// ...........................................................................
// return whatever we found, this is nullptr if the thing was not found
// and otherwise a valid pointer
// ...........................................................................
return b._table[i];
}
////////////////////////////////////////////////////////////////////////////////
/// @brief adds an key/element to the array
////////////////////////////////////////////////////////////////////////////////
int insert (Key const* key,
Element const* element,
bool isRollback) {
// ...........................................................................
// we are adding and the table is more than half full, extend it
// ...........................................................................
uint64_t i = _hashKey(key);
Bucket& b = _buckets[i & _bucketsMask];
if (! checkResize(b)) {
return TRI_ERROR_OUT_OF_MEMORY;
}
uint64_t const n = b._nrAlloc;
i = i % n;
uint64_t k = i;
for (; i < n && b._table[i] != nullptr &&
! _isEqualKeyElement(key, b._table[i]); ++i);
if (i == n) {
for (i = 0; i < k && b._table[i] != nullptr &&
! _isEqualKeyElement(key, b._table[i]); ++i);
}
Element* arrayElement = b._table[i];
// ...........................................................................
// if we found an element, return
// ...........................................................................
if (arrayElement != nullptr) {
return TRI_ERROR_ARANGO_UNIQUE_CONSTRAINT_VIOLATED;
}
b._table[i] = element;
TRI_ASSERT(b._table[i] != nullptr && b._table[i]->document() != nullptr);
b._nrUsed++;
return TRI_ERROR_NO_ERROR;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief removes an element from the array, returns nullptr if the element
/// was not found and the old value, if it was successfully removed
////////////////////////////////////////////////////////////////////////////////
Element* remove (Element* element) {
uint64_t i = _hashElement(element);
Bucket& b = _buckets[i & _bucketsMask];
uint64_t const n = b._nrAlloc;
i = i % n;
uint64_t k = i;
for (; i < n && b._table[i] != nullptr &&
element->document() != b._table[i]->document(); ++i);
if (i == n) {
for (i = 0; i < k && b._table[i] != nullptr &&
element->document() != b._table[i]->document(); ++i);
}
Element* old = b._table[i];
// ...........................................................................
// if we did not find such an item return error code
// ...........................................................................
if (old == nullptr) {
return old;
}
// ...........................................................................
// remove item - destroy any internal memory associated with the
// element structure
// ...........................................................................
b._table[i] = nullptr;
b._nrUsed--;
// ...........................................................................
// and now check the following places for items to move closer together
// so that there are no gaps in the array
// ...........................................................................
k = TRI_IncModU64(i, n);
while (b._table[k] != nullptr) {
uint64_t j = _hashElement(b._table[k]) % n;
if ((i < k && ! (i < j && j <= k)) || (k < i && ! (i < j || j <= k))) {
b._table[i] = b._table[k];
b._table[k] = nullptr;
i = k;
}
k = TRI_IncModU64(k, n);
}
if (b._nrUsed == 0) {
resizeInternal(b, initialSize(), true);
}
return old;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief a method to iterate over all elements in the hash
////////////////////////////////////////////////////////////////////////////////
void invokeOnAllElements (CallbackElementFuncType callback) {
for (auto& b : _buckets) {
if (b._table != nullptr) {
for (size_t i = 0; i < b._nrAlloc; ++i) {
if (b._table[i] != nullptr) {
callback(b._table[i]);
}
}
}
}
}
};
} // namespace basics
} // namespace triagens
#endif