데이터 구조

데이터 구조 (Data Structures, ds)

PHP 7에서 배열(array)의 대안으로 쓰는 효율적인 데이터 구조 확장이에요. 벡터, 데크, 맵, 셋, 스택, 큐 같은 자료구조를 성능에 맞게 제공해요. 배열로 하면 부담스러웠던 작업을 더 효율적으로 처리하고 싶을 때 써요.

출처: Data Structures

본문

소개

이 확장은 PHP 7용 효율적인 데이터 구조를 제공하며, 배열의 대안으로 설계됐어요. 벤치마크, 논의, 자주 묻는 질문은 공식 블로그 포스트를 참고하면 돼요.

제공하는 구조는 대략 이렇게 나뉘어요.

Collection / Sequence 인터페이스: 공통 동작을 정의하는 기반 인터페이스
Vector: 연속 메모리 배열, 인덱스 접근이 빠른 벡터
Deque: 앞뒤 양쪽에서 빠르게 넣고 빼는 데크
Map: 키-값 연관 배열
Set: 중복 없는 집합
Stack: LIFO 스택
Queue / PriorityQueue: FIFO 큐와 우선순위 큐
Pair: 키-값 쌍

대부분의 작업이 배열에 비해 메모리 사용과 속도 면에서 더 효율적이라, 대량 데이터를 다룰 때 특히 유용해요.

인터페이스·클래스 참조

이 페이지의 전체 API 목록은 아래와 같아요. (메서드는 각 클래스에서 공통 구현되어 유사한 이름을 공유해요.)

Ds\Collection / Ds\Hashable 인터페이스

Ds\Collection::clear — Removes all values
Ds\Collection::copy — Returns a shallow copy of the collection
Ds\Collection::isEmpty — Returns whether the collection is empty
Ds\Collection::toArray — Converts the collection to an array
Ds\Hashable::equals — Determines whether an object is equal to the current instance
Ds\Hashable::hash — Returns a scalar value to be used as a hash value

Ds\Sequence 인터페이스

Ds\Sequence::allocate — Allocates enough memory for a required capacity
Ds\Sequence::apply — Updates all values by applying a callback function to each value
Ds\Sequence::capacity — Returns the current capacity
Ds\Sequence::contains — Determines if the sequence contains given values
Ds\Sequence::filter — Creates a new sequence using a callable to determine which values to include
Ds\Sequence::find — Attempts to find a value's index
Ds\Sequence::first — Returns the first value in the sequence
Ds\Sequence::get — Returns the value at a given index
Ds\Sequence::insert — Inserts values at a given index
Ds\Sequence::join — Joins all values together as a string
Ds\Sequence::last — Returns the last value
Ds\Sequence::map — Returns the result of applying a callback to each value
Ds\Sequence::merge — Returns the result of adding all given values to the sequence
Ds\Sequence::pop — Removes and returns the last value
Ds\Sequence::push — Adds values to the end of the sequence
Ds\Sequence::reduce — Reduces the sequence to a single value using a callback function
Ds\Sequence::remove — Removes and returns a value by index
Ds\Sequence::reverse — Reverses the sequence in-place
Ds\Sequence::reversed — Returns a reversed copy
Ds\Sequence::rotate — Rotates the sequence by a given number of rotations
Ds\Sequence::set — Updates a value at a given index
Ds\Sequence::shift — Removes and returns the first value
Ds\Sequence::slice — Returns a sub-sequence of a given range
Ds\Sequence::sort — Sorts the sequence in-place
Ds\Sequence::sorted — Returns a sorted copy
Ds\Sequence::sum — Returns the sum of all values in the sequence
Ds\Sequence::unshift — Adds values to the front of the sequence

Ds\Vector 클래스

Ds\Vector::allocate — Allocates enough memory for a required capacity
Ds\Vector::apply — Updates all values by applying a callback function to each value
Ds\Vector::capacity — Returns the current capacity
Ds\Vector::clear — Removes all values
Ds\Vector::__construct — Creates a new instance
Ds\Vector::contains — Determines if the vector contains given values
Ds\Vector::copy — Returns a shallow copy of the vector
Ds\Vector::count — Returns the number of values in the collection
Ds\Vector::filter — Creates a new vector using a callable to determine which values to include
Ds\Vector::find — Attempts to find a value's index
Ds\Vector::first — Returns the first value in the vector
Ds\Vector::get — Returns the value at a given index
Ds\Vector::insert — Inserts values at a given index
Ds\Vector::isEmpty — Returns whether the vector is empty
Ds\Vector::join — Joins all values together as a string
Ds\Vector::jsonSerialize — Returns a representation that can be converted to JSON
Ds\Vector::last — Returns the last value
Ds\Vector::map — Returns the result of applying a callback to each value
Ds\Vector::merge — Returns the result of adding all given values to the vector
Ds\Vector::pop — Removes and returns the last value
Ds\Vector::push — Adds values to the end of the vector
Ds\Vector::reduce — Reduces the vector to a single value using a callback function
Ds\Vector::remove — Removes and returns a value by index
Ds\Vector::reverse — Reverses the vector in-place
Ds\Vector::reversed — Returns a reversed copy
Ds\Vector::rotate — Rotates the vector by a given number of rotations
Ds\Vector::set — Updates a value at a given index
Ds\Vector::shift — Removes and returns the first value
Ds\Vector::slice — Returns a sub-vector of a given range
Ds\Vector::sort — Sorts the vector in-place
Ds\Vector::sorted — Returns a sorted copy
Ds\Vector::sum — Returns the sum of all values in the vector
Ds\Vector::toArray — Converts the vector to an array
Ds\Vector::unshift — Adds values to the front of the vector

Ds\Deque 클래스

Ds\Deque::allocate — Allocates enough memory for a required capacity
Ds\Deque::apply — Updates all values by applying a callback function to each value
Ds\Deque::capacity — Returns the current capacity
Ds\Deque::clear — Removes all values from the deque
Ds\Deque::__construct — Creates a new instance
Ds\Deque::contains — Determines if the deque contains given values
Ds\Deque::copy — Returns a shallow copy of the deque
Ds\Deque::count — Returns the number of values in the collection
Ds\Deque::filter — Creates a new deque using a callable to determine which values to include
Ds\Deque::find — Attempts to find a value's index
Ds\Deque::first — Returns the first value in the deque
Ds\Deque::get — Returns the value at a given index
Ds\Deque::insert — Inserts values at a given index
Ds\Deque::isEmpty — Returns whether the deque is empty
Ds\Deque::join — Joins all values together as a string
Ds\Deque::jsonSerialize — Returns a representation that can be converted to JSON
Ds\Deque::last — Returns the last value
Ds\Deque::map — Returns the result of applying a callback to each value
Ds\Deque::merge — Returns the result of adding all given values to the deque
Ds\Deque::pop — Removes and returns the last value
Ds\Deque::push — Adds values to the end of the deque
Ds\Deque::reduce — Reduces the deque to a single value using a callback function
Ds\Deque::remove — Removes and returns a value by index
Ds\Deque::reverse — Reverses the deque in-place
Ds\Deque::reversed — Returns a reversed copy
Ds\Deque::rotate — Rotates the deque by a given number of rotations
Ds\Deque::set — Updates a value at a given index
Ds\Deque::shift — Removes and returns the first value
Ds\Deque::slice — Returns a sub-deque of a given range
Ds\Deque::sort — Sorts the deque in-place
Ds\Deque::sorted — Returns a sorted copy
Ds\Deque::sum — Returns the sum of all values in the deque
Ds\Deque::toArray — Converts the deque to an array
Ds\Deque::unshift — Adds values to the front of the deque

Ds\Map 클래스

Ds\Map::allocate — Allocates enough memory for a required capacity
Ds\Map::apply — Updates all values by applying a callback function to each value
Ds\Map::capacity — Returns the current capacity
Ds\Map::clear — Removes all values
Ds\Map::__construct — Creates a new instance
Ds\Map::copy — Returns a shallow copy of the map
Ds\Map::count — Returns the number of values in the map
Ds\Map::diff — Creates a new map using keys that aren't in another map
Ds\Map::filter — Creates a new map using a callable to determine which pairs to include
Ds\Map::first — Returns the first pair in the map
Ds\Map::get — Returns the value for a given key
Ds\Map::hasKey — Determines whether the map contains a given key
Ds\Map::hasValue — Determines whether the map contains a given value
Ds\Map::intersect — Creates a new map by intersecting keys with another map
Ds\Map::isEmpty — Returns whether the map is empty
Ds\Map::jsonSerialize — Returns a representation that can be converted to JSON
Ds\Map::keys — Returns a set of the map's keys
Ds\Map::ksort — Sorts the map in-place by key
Ds\Map::ksorted — Returns a copy, sorted by key
Ds\Map::last — Returns the last pair of the map
Ds\Map::map — Returns the result of applying a callback to each value
Ds\Map::merge — Returns the result of adding all given associations
Ds\Map::pairs — Returns a sequence containing all the pairs of the map
Ds\Map::put — Associates a key with a value
Ds\Map::putAll — Associates all key-value pairs of a traversable object or array
Ds\Map::reduce — Reduces the map to a single value using a callback function
Ds\Map::remove — Removes and returns a value by key
Ds\Map::reverse — Reverses the map in-place
Ds\Map::reversed — Returns a reversed copy
Ds\Map::skip — Returns the pair at a given positional index
Ds\Map::slice — Returns a subset of the map defined by a starting index and length
Ds\Map::sort — Sorts the map in-place by value
Ds\Map::sorted — Returns a copy, sorted by value
Ds\Map::sum — Returns the sum of all values in the map
Ds\Map::toArray — Converts the map to an array
Ds\Map::union — Creates a new map using values from the current instance and another map
Ds\Map::values — Returns a sequence of the map's values
Ds\Map::xor — Creates a new map using keys of either the current instance or of another map, but not of both

Ds\Pair 클래스

Ds\Pair::clear — Removes all values
Ds\Pair::__construct — Creates a new instance
Ds\Pair::copy — Returns a shallow copy of the pair
Ds\Pair::isEmpty — Returns whether the pair is empty
Ds\Pair::jsonSerialize — Returns a representation that can be converted to JSON
Ds\Pair::toArray — Converts the pair to an array

Ds\Set 클래스

Ds\Set::add — Adds values to the set
Ds\Set::allocate — Allocates enough memory for a required capacity
Ds\Set::capacity — Returns the current capacity
Ds\Set::clear — Removes all values
Ds\Set::__construct — Creates a new instance
Ds\Set::contains — Determines if the set contains all values
Ds\Set::copy — Returns a shallow copy of the set
Ds\Set::count — Returns the number of values in the set
Ds\Set::diff — Creates a new set using values that aren't in another set
Ds\Set::filter — Creates a new set using a callable to determine which values to include
Ds\Set::first — Returns the first value in the set
Ds\Set::get — Returns the value at a given index
Ds\Set::intersect — Creates a new set by intersecting values with another set
Ds\Set::isEmpty — Returns whether the set is empty
Ds\Set::join — Joins all values together as a string
Ds\Set::jsonSerialize — Returns a representation that can be converted to JSON
Ds\Set::last — Returns the last value in the set
Ds\Set::map — Returns the result of applying a callback to each value
Ds\Set::merge — Returns the result of adding all given values to the set
Ds\Set::reduce — Reduces the set to a single value using a callback function
Ds\Set::remove — Removes all given values from the set
Ds\Set::reverse — Reverses the set in-place
Ds\Set::reversed — Returns a reversed copy
Ds\Set::slice — Returns a sub-set of a given range
Ds\Set::sort — Sorts the set in-place
Ds\Set::sorted — Returns a sorted copy
Ds\Set::sum — Returns the sum of all values in the set
Ds\Set::toArray — Converts the set to an array
Ds\Set::union — Creates a new set using values from the current instance and another set
Ds\Set::xor — Creates a new set using values in either the current instance or in another set, but not in both

Ds\Stack 클래스

Ds\Stack::allocate — Allocates enough memory for a required capacity
Ds\Stack::capacity — Returns the current capacity
Ds\Stack::clear — Removes all values
Ds\Stack::__construct — Creates a new instance
Ds\Stack::copy — Returns a shallow copy of the stack
Ds\Stack::count — Returns the number of values in the stack
Ds\Stack::isEmpty — Returns whether the stack is empty
Ds\Stack::jsonSerialize — Returns a representation that can be converted to JSON
Ds\Stack::peek — Returns the value at the top of the stack
Ds\Stack::pop — Removes and returns the value at the top of the stack
Ds\Stack::push — Pushes values onto the stack
Ds\Stack::toArray — Converts the stack to an array

Ds\Queue 클래스

Ds\Queue::allocate — Allocates enough memory for a required capacity
Ds\Queue::capacity — Returns the current capacity
Ds\Queue::clear — Removes all values
Ds\Queue::__construct — Creates a new instance
Ds\Queue::copy — Returns a shallow copy of the queue
Ds\Queue::count — Returns the number of values in the queue
Ds\Queue::isEmpty — Returns whether the queue is empty
Ds\Queue::jsonSerialize — Returns a representation that can be converted to JSON
Ds\Queue::peek — Returns the value at the front of the queue
Ds\Queue::pop — Removes and returns the value at the front of the queue
Ds\Queue::push — Pushes values into the queue
Ds\Queue::toArray — Converts the queue to an array

Ds\PriorityQueue 클래스

Ds\PriorityQueue::allocate — Allocates enough memory for a required capacity
Ds\PriorityQueue::capacity — Returns the current capacity
Ds\PriorityQueue::clear — Removes all values
Ds\PriorityQueue::__construct — Creates a new instance
Ds\PriorityQueue::copy — Returns a shallow copy of the queue
Ds\PriorityQueue::count — Returns the number of values in the queue
Ds\PriorityQueue::isEmpty — Returns whether the queue is empty
Ds\PriorityQueue::jsonSerialize — Returns a representation that can be converted to JSON
Ds\PriorityQueue::peek — Returns the value at the front of the queue
Ds\PriorityQueue::pop — Removes and returns the value with the highest priority
Ds\PriorityQueue::push — Pushes values into the queue
Ds\PriorityQueue::toArray — Converts the queue to an array

더 알아보기

대부분의 Ds\* 구조는 배열과 비슷한 느낌으로 쓰되 성능 특징이 달라요. 예를 들어 벡터는 인덱스 접근이 빠르고, 데크는 앞뒤 삽입·삭제가 빨라요. 작업 특성에 맞는 구조를 고르는 게 중요해요.
성능 비교와 자주 묻는 질문은 공식 블로그 포스트에서 확인할 수 있어요.