Awesome
mm-go Generic manual memory management for golang
Golang manages memory via GC and it's good for almost every use case but sometimes it can be a bottleneck. and this is where mm-go comes in to play.
Before using mm-go
- Golang doesn't have any way to manually allocate/free memory, so how does mm-go allocate/free? It does so via cgo.
- Before considering using this try to optimize your program to use less pointers, as golang GC most of the time performs worse when there is a lot of pointers, if you can't use this lib.
- Manual memory management provides better performance (most of the time) but you are 100% responsible for managing it (bugs, segfaults, use after free, double free, ....)
- Don't mix Manually and Managed memory (example if you put a slice in a manually managed struct it will get collected because go GC doesn't see the manually allocated struct, use Vector instead)
- All data structures provided by the package are manually managed and thus can be safely included in manually managed structs without the GC freeing them, but you have to free them yourself!
- Try to minimize calls to cgo by preallocating (using batchallocator/Arena/AllocMany).
- Check the docs, test files and read the README.
Installing
go get -u github.com/joetifa2003/mm-go
At a glance
type MyStruct struct {
a int
b float32
}
func Example_datastructures() {
alloc := allocator.NewC()
defer alloc.Destroy()
p := allocator.Alloc[MyStruct](alloc)
defer allocator.Free(alloc, p)
p.a = 100
p.b = 200
fmt.Println(*p)
v := vector.New[int](alloc)
defer v.Free()
v.Push(15)
v.Push(70)
for _, i := range v.Iter() {
fmt.Println(i)
}
l := linkedlist.New[*mmstring.MMString](alloc)
defer l.Free()
l.PushBack(mmstring.From(alloc, "hello"))
l.PushBack(mmstring.From(alloc, "world"))
for _, i := range l.Iter() {
fmt.Println(i.GetGoString())
}
// Output:
// {100 200}
// 15
// 70
// hello
// world
}
mm-go
is built around the concept of Allocators, which is an interface that can be implemented and passed around to the library.
You use these allocators to allocate memory, and also allocate datastructures like vectors, linkedlists, hashmaps, etc.
Benchmarks
Check the test files and github actions for the benchmarks (linux, macos, windows). mm-go can sometimes be 5-10 times faster.
Run go test ./... -bench=. -count 5 > out.txt && benchstat out.txt
goos: linux
goarch: amd64
pkg: github.com/joetifa2003/mm-go
cpu: AMD Ryzen 7 5800H with Radeon Graphics
│ out.txt │
│ sec/op │
LinkedListManaged-16 605.7µ ± ∞ ¹
LinkedListCAlloc-16 933.1µ ± ∞ ¹
LinkedListBatchAllocator/bucket_size_100-16 513.3µ ± ∞ ¹
LinkedListBatchAllocator/bucket_size_200-16 405.8µ ± ∞ ¹
LinkedListBatchAllocator/bucket_size_500-16 425.4µ ± ∞ ¹
LinkedListBatchAllocator/bucket_size_10000-16 200.7µ ± ∞ ¹
LinkedListTypedArena/chunk_size_100-16 105.3µ ± ∞ ¹
LinkedListTypedArena/chunk_size_200-16 95.50µ ± ∞ ¹
LinkedListTypedArena/chunk_size_500-16 83.02µ ± ∞ ¹
LinkedListTypedArena/chunk_size_10000-16 75.96µ ± ∞ ¹
geomean 240.1µ
¹ need >= 6 samples for confidence interval at level 0.95
pkg: github.com/joetifa2003/mm-go/hashmap
│ out.txt │
│ sec/op │
HashmapGo-16 210.7µ ± ∞ ¹
HashmapCAlloc-16 189.1µ ± ∞ ¹
HashmapBatchAlloc-16 118.2µ ± ∞ ¹
geomean 167.6µ
¹ need >= 6 samples for confidence interval at level 0.95
<!-- gomarkdoc:embed:start -->
<!-- Code generated by gomarkdoc. DO NOT EDIT -->
mm
import "github.com/joetifa2003/mm-go"
Index
<a name="SizeOf"></a>
func SizeOf
func SizeOf[T any]() int
SizeOf returns the size of T in bytes
<details><summary>Example</summary> <p>fmt.Println(mm.SizeOf[int32]())
fmt.Println(mm.SizeOf[int64]())
// Output:
// 4
// 8
Output
4
8
</p>
</details>
<a name="Zero"></a>
func Zero
func Zero[T any]() T
Zero returns a zero value of T
allocator
import "github.com/joetifa2003/mm-go/allocator"
<details><summary>Example</summary>
<p>
package main
import (
"fmt"
"github.com/joetifa2003/mm-go/allocator"
)
func main() {
alloc := allocator.NewC()
defer alloc.Destroy()
ptr := allocator.Alloc[int](alloc)
defer allocator.Free(alloc, ptr)
*ptr = 15
fmt.Println(*ptr)
}
Output
15
</p>
</details>
<details><summary>Example (Datastructures)</summary>
<p>
package main
import (
"fmt"
"github.com/joetifa2003/mm-go/allocator"
"github.com/joetifa2003/mm-go/linkedlist"
"github.com/joetifa2003/mm-go/mmstring"
"github.com/joetifa2003/mm-go/vector"
)
type MyStruct struct {
a int
b float32
}
func main() {
alloc := allocator.NewC()
defer alloc.Destroy() // all the memory allocated bellow will be freed, no need to free it manually.
p := allocator.Alloc[MyStruct](alloc)
defer allocator.Free(alloc, p)
p.a = 100
p.b = 200
fmt.Println(*p)
v := vector.New[int](alloc)
defer v.Free()
v.Push(15)
v.Push(70)
for _, i := range v.Iter() {
fmt.Println(i)
}
l := linkedlist.New[*mmstring.MMString](alloc)
defer l.Free()
l.PushBack(mmstring.From(alloc, "hello"))
l.PushBack(mmstring.From(alloc, "world"))
for _, i := range l.Iter() {
fmt.Println(i.GetGoString())
}
}
Output
{100 200}
15
70
hello
world
</p>
</details>
Index
- func Alloc[T any](a Allocator) *T
- func AllocMany[T any](a Allocator, n int) []T
- func Free[T any](a Allocator, ptr *T)
- func FreeMany[T any](a Allocator, slice []T)
- func Realloc[T any](a Allocator, slice []T, newN int) []T
- type Allocator
- func NewAllocator(allocator unsafe.Pointer, alloc func(allocator unsafe.Pointer, size int) unsafe.Pointer, free func(allocator unsafe.Pointer, ptr unsafe.Pointer), realloc func(allocator unsafe.Pointer, ptr unsafe.Pointer, size int) unsafe.Pointer, destroy func(allocator unsafe.Pointer)) Allocator
- func NewC() Allocator
- func (a Allocator) Alloc(size int) unsafe.Pointer
- func (a Allocator) Destroy()
- func (a Allocator) Free(ptr unsafe.Pointer)
- func (a Allocator) Realloc(ptr unsafe.Pointer, size int) unsafe.Pointer
<a name="Alloc"></a>
func Alloc
func Alloc[T any](a Allocator) *T
Alloc allocates T and returns a pointer to it.
<details><summary>Example</summary> <p>alloc := allocator.NewC()
defer alloc.Destroy()
// So you can do this:
ptr := allocator.Alloc[int](alloc) // allocates a single int and returns a ptr to it
defer allocator.Free(alloc, ptr) // frees the int (defer recommended to prevent leaks)
*ptr = 15
fmt.Println(*ptr)
// instead of doing this:
ptr2 := (*int)(alloc.Alloc(mm.SizeOf[int]()))
defer alloc.Free(unsafe.Pointer(ptr2))
*ptr2 = 15
fmt.Println(*ptr2)
// Output:
// 15
// 15
Output
15
15
</p>
</details>
<a name="AllocMany"></a>
func AllocMany
func AllocMany[T any](a Allocator, n int) []T
AllocMany allocates n of T and returns a slice representing the heap. CAUTION: don't append to the slice, the purpose of it is to replace pointer arithmetic with slice indexing
<details><summary>Example</summary> <p>package main
import (
"fmt"
"github.com/joetifa2003/mm-go/allocator"
)
func main() {
alloc := allocator.NewC()
defer alloc.Destroy()
heap := allocator.AllocMany[int](alloc, 2) // allocates 2 ints and returns it as a slice of ints with length 2
defer allocator.FreeMany(alloc, heap) // it's recommended to make sure the data gets deallocated (defer recommended to prevent leaks)
heap[0] = 15 // changes the data in the slice (aka the heap)
ptr := &heap[0] // takes a pointer to the first int in the heap
// Be careful if you do ptr := heap[0] this will take a copy from the data on the heap
*ptr = 45 // changes the value from 15 to 45
heap[1] = 70
fmt.Println(heap[0])
fmt.Println(heap[1])
}
Output
45
70
</p>
</details>
<a name="Free"></a>
func Free
func Free[T any](a Allocator, ptr *T)
FreeMany frees memory allocated by Alloc takes a ptr CAUTION: be careful not to double free, and prefer using defer to deallocate
<a name="FreeMany"></a>
func FreeMany
func FreeMany[T any](a Allocator, slice []T)
FreeMany frees memory allocated by AllocMany takes in the slice (aka the heap) CAUTION: be careful not to double free, and prefer using defer to deallocate
<a name="Realloc"></a>
func Realloc
func Realloc[T any](a Allocator, slice []T, newN int) []T
Realloc reallocates memory allocated with AllocMany and doesn't change underling data
<details><summary>Example</summary> <p>package main
import (
"fmt"
"github.com/joetifa2003/mm-go/allocator"
)
func main() {
alloc := allocator.NewC()
defer alloc.Destroy()
heap := allocator.AllocMany[int](alloc, 2) // allocates 2 int and returns it as a slice of ints with length 2
heap[0] = 15
heap[1] = 70
heap = allocator.Realloc(alloc, heap, 3)
heap[2] = 100
fmt.Println(heap[0])
fmt.Println(heap[1])
fmt.Println(heap[2])
allocator.FreeMany(alloc, heap)
}
Output
15
70
100
</p>
</details>
<a name="Allocator"></a>
type Allocator
Allocator is an interface that defines some methods needed for most allocators. It's not a golang interface, so it's safe to use in manually managed structs (will not get garbage collected).
type Allocator struct {
// contains filtered or unexported fields
}
<a name="NewAllocator"></a>
func NewAllocator
func NewAllocator(allocator unsafe.Pointer, alloc func(allocator unsafe.Pointer, size int) unsafe.Pointer, free func(allocator unsafe.Pointer, ptr unsafe.Pointer), realloc func(allocator unsafe.Pointer, ptr unsafe.Pointer, size int) unsafe.Pointer, destroy func(allocator unsafe.Pointer)) Allocator
NewAllocator creates a new Allocator
<details><summary>Example</summary> <p>package main
import (
"unsafe"
"github.com/joetifa2003/mm-go/allocator"
)
func main() {
// Create a custom allocator
alloc := allocator.NewAllocator(
nil,
myallocator_alloc,
myallocator_free,
myallocator_realloc,
myallocator_destroy,
)
// Check how C allocator is implemented
// or batchallocator source for a reference
_ = alloc
}
func myallocator_alloc(allocator unsafe.Pointer, size int) unsafe.Pointer {
return nil
}
func myallocator_free(allocator unsafe.Pointer, ptr unsafe.Pointer) {
}
func myallocator_realloc(allocator unsafe.Pointer, ptr unsafe.Pointer, size int) unsafe.Pointer {
return nil
}
func myallocator_destroy(allocator unsafe.Pointer) {
}
</p>
</details>
<a name="NewC"></a>
func NewC
func NewC() Allocator
NewC returns an allocator that uses C calloc, realloc and free.
<a name="Allocator.Alloc"></a>
func (Allocator) Alloc
func (a Allocator) Alloc(size int) unsafe.Pointer
Alloc allocates size bytes and returns an unsafe pointer to it.
<a name="Allocator.Destroy"></a>
func (Allocator) Destroy
func (a Allocator) Destroy()
Destroy destroys the allocator. After calling this, the allocator is no longer usable. This is useful for cleanup, freeing allocator internal resources, etc.
<a name="Allocator.Free"></a>
func (Allocator) Free
func (a Allocator) Free(ptr unsafe.Pointer)
Free frees the memory pointed by ptr
<a name="Allocator.Realloc"></a>
func (Allocator) Realloc
func (a Allocator) Realloc(ptr unsafe.Pointer, size int) unsafe.Pointer
Realloc reallocates the memory pointed by ptr with a new size and returns a new pointer to it.
batchallocator
import "github.com/joetifa2003/mm-go/batchallocator"
This allocator purpose is to reduce the overhead of calling CGO on every allocation/free, it also acts as an arena since it frees all the memory when `Destroy` is called. It allocats large chunks of memory at once and then divides them when you allocate, making it much faster. This allocator has to take another allocator for it to work, usually with the C allocator. You can optionally call `Free` on the pointers allocated by batchallocator manually, and it will free the memory as soon as it can. `Destroy` must be called to free internal resources and free all the memory allocated by the allocator.
<details><summary>Example</summary> <p>package main
import (
"github.com/joetifa2003/mm-go/allocator"
"github.com/joetifa2003/mm-go/batchallocator"
)
func main() {
alloc := batchallocator.New(allocator.NewC()) // by default it allocates page, which is usually 4kb
defer alloc.Destroy() // this frees all memory allocated by the allocator automatically
ptr := allocator.Alloc[int](alloc)
// but you can still free the pointers manually if you want (will free buckets of memory if all pointers depending on it is freed)
defer allocator.Free(alloc, ptr) // this can removed and the memory will be freed.
}
</p>
</details>
<details><summary>Example (Arena)</summary>
<p>
package main
import (
"fmt"
"github.com/joetifa2003/mm-go/allocator"
"github.com/joetifa2003/mm-go/batchallocator"
"github.com/joetifa2003/mm-go/linkedlist"
"github.com/joetifa2003/mm-go/mmstring"
"github.com/joetifa2003/mm-go/vector"
)
func main() {
alloc := batchallocator.New(allocator.NewC())
defer alloc.Destroy() // all the memory allocated bellow will be freed, no need to free it manually.
v := vector.New[int](alloc)
v.Push(15)
v.Push(70)
for _, i := range v.Iter() {
fmt.Println(i)
}
l := linkedlist.New[*mmstring.MMString](alloc)
l.PushBack(mmstring.From(alloc, "hello"))
l.PushBack(mmstring.From(alloc, "world"))
for _, i := range l.Iter() {
fmt.Println(i.GetGoString())
}
}
Output
15
70
hello
world
</p>
</details>
Index
- func New(a allocator.Allocator, options ...BatchAllocatorOption) allocator.Allocator
- type BatchAllocator
- type BatchAllocatorOption
<a name="New"></a>
func New
func New(a allocator.Allocator, options ...BatchAllocatorOption) allocator.Allocator
New creates a new BatchAllocator and applies optional configuration using BatchAllocatorOption
<a name="BatchAllocator"></a>
type BatchAllocator
BatchAllocator manages a collection of memory buckets to optimize small allocations
type BatchAllocator struct {
// contains filtered or unexported fields
}
<a name="BatchAllocatorOption"></a>
type BatchAllocatorOption
type BatchAllocatorOption func(alloc *BatchAllocator)
<a name="WithBucketSize"></a>
func WithBucketSize
func WithBucketSize(size int) BatchAllocatorOption
WithBucketSize Option to specify bucket size when creating BatchAllocator You can allocate more memory than the bucketsize in one allocation, it will allocate a new bucket and put the data in it.
<details><summary>Example</summary> <p>alloc := batchallocator.New(
allocator.NewC(),
batchallocator.WithBucketSize(mm.SizeOf[int]()*15), // configure the allocator to allocate size of 15 ints per bucket.
)
defer alloc.Destroy()
ptr := allocator.Alloc[int](alloc)
defer allocator.Free(alloc, ptr) // this can be removed and the memory will still be freed on Destroy.
ptr2 := allocator.Alloc[int](alloc) // will not call CGO because there is still enough memory in the Bucket.
defer allocator.Free(alloc, ptr2) // this can be removed and the memory will still be freed on Destroy.
</p>
</details>
hashmap
import "github.com/joetifa2003/mm-go/hashmap"
<details><summary>Example</summary>
<p>
alloc := batchallocator.New(allocator.NewC())
defer alloc.Destroy()
hm := New[int, int](alloc)
defer hm.Free() // can be removed
hm.Set(1, 10)
hm.Set(2, 20)
hm.Set(3, 30)
sumKeys := 0
sumValues := 0
for k, v := range hm.Iter() {
sumKeys += k
sumValues += v
}
fmt.Println(sumKeys)
fmt.Println(sumValues)
// Output:
// 6
// 60
Output
6
60
</p>
</details>
Index
- type Hashmap
- func New[K comparable, V any](alloc allocator.Allocator) *Hashmap[K, V]
- func (hm *Hashmap[K, V]) Delete(key K)
- func (hm *Hashmap[K, V]) Free()
- func (hm *Hashmap[K, V]) Get(key K) (value V, exists bool)
- func (hm *Hashmap[K, V]) GetPtr(key K) (value *V, exists bool)
- func (hm *Hashmap[K, V]) Iter() iter.Seq2[K, V]
- func (hm *Hashmap[K, V]) Keys() []K
- func (hm *Hashmap[K, V]) Set(key K, value V)
- func (hm *Hashmap[K, V]) Values() []V
<a name="Hashmap"></a>
type Hashmap
Hashmap Manually managed hashmap,
type Hashmap[K comparable, V any] struct {
// contains filtered or unexported fields
}
<a name="New"></a>
func New
func New[K comparable, V any](alloc allocator.Allocator) *Hashmap[K, V]
New creates a new Hashmap with key of type K and value of type V
<a name="Hashmap[K, V].Delete"></a>
func (*Hashmap[K, V]) Delete
func (hm *Hashmap[K, V]) Delete(key K)
Delete delete value with key K
<a name="Hashmap[K, V].Free"></a>
func (*Hashmap[K, V]) Free
func (hm *Hashmap[K, V]) Free()
Free frees the Hashmap
<a name="Hashmap[K, V].Get"></a>
func (*Hashmap[K, V]) Get
func (hm *Hashmap[K, V]) Get(key K) (value V, exists bool)
Get takes key K and return value V
<a name="Hashmap[K, V].GetPtr"></a>
func (*Hashmap[K, V]) GetPtr
func (hm *Hashmap[K, V]) GetPtr(key K) (value *V, exists bool)
GetPtr takes key K and return a pointer to value V
<a name="Hashmap[K, V].Iter"></a>
func (*Hashmap[K, V]) Iter
func (hm *Hashmap[K, V]) Iter() iter.Seq2[K, V]
Iter returns an iterator over all key/value pairs
<a name="Hashmap[K, V].Keys"></a>
func (*Hashmap[K, V]) Keys
func (hm *Hashmap[K, V]) Keys() []K
Keys returns all keys as a slice
<a name="Hashmap[K, V].Set"></a>
func (*Hashmap[K, V]) Set
func (hm *Hashmap[K, V]) Set(key K, value V)
Set inserts a new value V if key K doesn't exist, Otherwise update the key K with value V
<a name="Hashmap[K, V].Values"></a>
func (*Hashmap[K, V]) Values
func (hm *Hashmap[K, V]) Values() []V
Values returns all values as a slice
linkedlist
import "github.com/joetifa2003/mm-go/linkedlist"
<details><summary>Example</summary>
<p>
alloc := allocator.NewC()
defer alloc.Destroy()
ll := New[int](alloc)
defer ll.Free()
ll.PushBack(1)
ll.PushBack(2)
ll.PushBack(3)
ll.PushBack(4)
fmt.Println("PopBack:", ll.PopBack())
fmt.Println("PopFront:", ll.PopFront())
for _, i := range ll.Iter() {
fmt.Println(i)
}
// Output:
// PopBack: 4
// PopFront: 1
// 2
// 3
Output
PopBack: 4
PopFront: 1
2
3
</p>
</details>
Index
- type LinkedList
- func New[T any](alloc allocator.Allocator) *LinkedList[T]
- func (ll *LinkedList[T]) At(idx int) T
- func (ll *LinkedList[T]) AtPtr(idx int) *T
- func (ll *LinkedList[T]) FindIndex(f func(value T) bool) (idx int, ok bool)
- func (ll *LinkedList[T]) FindIndexes(f func(value T) bool) []int
- func (ll *LinkedList[T]) ForEach(f func(idx int, value T))
- func (ll *LinkedList[T]) Free()
- func (ll *LinkedList[T]) Iter() iter.Seq2[int, T]
- func (ll *LinkedList[T]) Len() int
- func (ll *LinkedList[T]) PopBack() T
- func (ll *LinkedList[T]) PopFront() T
- func (ll *LinkedList[T]) PushBack(value T)
- func (ll *LinkedList[T]) PushFront(value T)
- func (ll *LinkedList[T]) Remove(f func(idx int, value T) bool) (value T, ok bool)
- func (ll *LinkedList[T]) RemoveAll(f func(idx int, value T) bool) []T
- func (ll *LinkedList[T]) RemoveAt(idx int) T
<a name="LinkedList"></a>
type LinkedList
LinkedList a doubly-linked list. Note: can be a lot slower than Vector but sometimes faster in specific use cases
type LinkedList[T any] struct {
// contains filtered or unexported fields
}
<a name="New"></a>
func New
func New[T any](alloc allocator.Allocator) *LinkedList[T]
New creates a new linked list.
<a name="LinkedList[T].At"></a>
func (*LinkedList[T]) At
func (ll *LinkedList[T]) At(idx int) T
At gets value T at idx.
<a name="LinkedList[T].AtPtr"></a>
func (*LinkedList[T]) AtPtr
func (ll *LinkedList[T]) AtPtr(idx int) *T
AtPtr gets a pointer to value T at idx.
<a name="LinkedList[T].FindIndex"></a>
func (*LinkedList[T]) FindIndex
func (ll *LinkedList[T]) FindIndex(f func(value T) bool) (idx int, ok bool)
FindIndex returns the first index of value T that pass the test implemented by the provided function.
<a name="LinkedList[T].FindIndexes"></a>
func (*LinkedList[T]) FindIndexes
func (ll *LinkedList[T]) FindIndexes(f func(value T) bool) []int
FindIndex returns all indexes of value T that pass the test implemented by the provided function.
<a name="LinkedList[T].ForEach"></a>
func (*LinkedList[T]) ForEach
func (ll *LinkedList[T]) ForEach(f func(idx int, value T))
ForEach iterates through the linked list.
<a name="LinkedList[T].Free"></a>
func (*LinkedList[T]) Free
func (ll *LinkedList[T]) Free()
Free frees the linked list.
<a name="LinkedList[T].Iter"></a>
func (*LinkedList[T]) Iter
func (ll *LinkedList[T]) Iter() iter.Seq2[int, T]
Iter returns an iterator over the linked list values.
<a name="LinkedList[T].Len"></a>
func (*LinkedList[T]) Len
func (ll *LinkedList[T]) Len() int
Len gets linked list length.
<a name="LinkedList[T].PopBack"></a>
func (*LinkedList[T]) PopBack
func (ll *LinkedList[T]) PopBack() T
PopBack pops and returns value T from the back of the linked list.
<a name="LinkedList[T].PopFront"></a>
func (*LinkedList[T]) PopFront
func (ll *LinkedList[T]) PopFront() T
PopFront pops and returns value T from the front of the linked list.
<a name="LinkedList[T].PushBack"></a>
func (*LinkedList[T]) PushBack
func (ll *LinkedList[T]) PushBack(value T)
PushBack pushes value T to the back of the linked list.
<a name="LinkedList[T].PushFront"></a>
func (*LinkedList[T]) PushFront
func (ll *LinkedList[T]) PushFront(value T)
PushFront pushes value T to the back of the linked list.
<a name="LinkedList[T].Remove"></a>
func (*LinkedList[T]) Remove
func (ll *LinkedList[T]) Remove(f func(idx int, value T) bool) (value T, ok bool)
Remove removes the first value T that pass the test implemented by the provided function. if the test succeeded it will return the value and true
<a name="LinkedList[T].RemoveAll"></a>
func (*LinkedList[T]) RemoveAll
func (ll *LinkedList[T]) RemoveAll(f func(idx int, value T) bool) []T
RemoveAll removes all values of T that pass the test implemented by the provided function.
<a name="LinkedList[T].RemoveAt"></a>
func (*LinkedList[T]) RemoveAt
func (ll *LinkedList[T]) RemoveAt(idx int) T
RemoveAt removes value T at specified index and returns it.
minheap
import "github.com/joetifa2003/mm-go/minheap"
<details><summary>Example</summary>
<p>
package main
import (
"fmt"
"github.com/joetifa2003/mm-go/allocator"
"github.com/joetifa2003/mm-go/minheap"
)
func int_less(a, b int) bool { return a < b }
func main() {
alloc := allocator.NewC()
defer alloc.Destroy()
h := minheap.New[int](alloc, int_less)
// Push some values onto the heap
h.Push(2)
h.Push(1)
h.Push(4)
h.Push(3)
h.Push(5)
// Pop the minimum value from the heap
fmt.Println(h.Pop())
fmt.Println(h.Pop())
}
Output
1
2
</p>
</details>
<details><summary>Example (-ax Heap)</summary>
<p>
package main
import (
"fmt"
"github.com/joetifa2003/mm-go/allocator"
"github.com/joetifa2003/mm-go/minheap"
)
func int_greater(a, b int) bool { return a > b }
func main() {
alloc := allocator.NewC()
defer alloc.Destroy()
h := minheap.New[int](alloc, int_greater)
// Push some values onto the heap
h.Push(2)
h.Push(1)
h.Push(4)
h.Push(3)
h.Push(5)
// Pop the max value from the heap
fmt.Println(h.Pop())
fmt.Println(h.Pop())
}
Output
5
4
</p>
</details>
Index
- type MinHeap
- func New[T any](alloc allocator.Allocator, less func(a, b T) bool) *MinHeap[T]
- func (h *MinHeap[T]) Free()
- func (h *MinHeap[T]) Iter() iter.Seq2[int, T]
- func (h *MinHeap[T]) Len() int
- func (h *MinHeap[T]) Peek() T
- func (h *MinHeap[T]) Pop() T
- func (h *MinHeap[T]) Push(value T)
- func (h *MinHeap[T]) Remove(f func(T) bool)
<a name="MinHeap"></a>
type MinHeap
type MinHeap[T any] struct {
// contains filtered or unexported fields
}
<a name="New"></a>
func New
func New[T any](alloc allocator.Allocator, less func(a, b T) bool) *MinHeap[T]
New creates a new MinHeap.
<a name="MinHeap[T].Free"></a>
func (*MinHeap[T]) Free
func (h *MinHeap[T]) Free()
Free frees the heap.
<a name="MinHeap[T].Iter"></a>
func (*MinHeap[T]) Iter
func (h *MinHeap[T]) Iter() iter.Seq2[int, T]
Iter returns an iterator over the elements of the heap.
<a name="MinHeap[T].Len"></a>
func (*MinHeap[T]) Len
func (h *MinHeap[T]) Len() int
Len returns the number of elements in the heap.
<a name="MinHeap[T].Peek"></a>
func (*MinHeap[T]) Peek
func (h *MinHeap[T]) Peek() T
Peek returns the minimum value from the heap without removing it.
<a name="MinHeap[T].Pop"></a>
func (*MinHeap[T]) Pop
func (h *MinHeap[T]) Pop() T
Pop removes and returns the minimum value from the heap.
<a name="MinHeap[T].Push"></a>
func (*MinHeap[T]) Push
func (h *MinHeap[T]) Push(value T)
Push adds a value to the heap.
<a name="MinHeap[T].Remove"></a>
func (*MinHeap[T]) Remove
func (h *MinHeap[T]) Remove(f func(T) bool)
Remove the first element that makes f return true
mmstring
import "github.com/joetifa2003/mm-go/mmstring"
<details><summary>Example</summary>
<p>
package main
import (
"fmt"
"github.com/joetifa2003/mm-go/allocator"
"github.com/joetifa2003/mm-go/mmstring"
)
func main() {
alloc := allocator.NewC()
defer alloc.Destroy()
s := mmstring.New(alloc)
defer s.Free()
s.AppendGoString("Hello ")
s.AppendGoString("World")
s2 := mmstring.From(alloc, "Foo Bar")
defer s2.Free()
fmt.Println(s.GetGoString())
fmt.Println(s2.GetGoString())
}
Output
Hello World
Foo Bar
</p>
</details>
<details><summary>Example (Datastructures)</summary>
<p>
package main
import (
"fmt"
"github.com/joetifa2003/mm-go/allocator"
"github.com/joetifa2003/mm-go/batchallocator"
"github.com/joetifa2003/mm-go/mmstring"
"github.com/joetifa2003/mm-go/vector"
)
func main() {
alloc := batchallocator.New(allocator.NewC())
defer alloc.Destroy() // all the memory allocated bellow will be freed, no need to free it manually.
m := vector.New[*mmstring.MMString](alloc)
m.Push(mmstring.From(alloc, "hello"))
m.Push(mmstring.From(alloc, "world"))
for k, v := range m.Iter() {
fmt.Println(k, v.GetGoString())
}
}
Output
0 hello
1 world
</p>
</details>
Index
<a name="MMString"></a>
type MMString
MMString is a manually manged string that is basically a *Vector[rune] and contains all the methods of a vector plus additional helper functions
type MMString struct {
// contains filtered or unexported fields
}
<a name="From"></a>
func From
func From(alloc allocator.Allocator, input string) *MMString
From creates a new manually managed string, And initialize it with a go string
<a name="New"></a>
func New
func New(alloc allocator.Allocator) *MMString
New create a new manually managed string
<a name="MMString.AppendGoString"></a>
func (*MMString) AppendGoString
func (s *MMString) AppendGoString(input string)
AppendGoString appends go string to manually managed string
<a name="MMString.Free"></a>
func (*MMString) Free
func (s *MMString) Free()
Free frees MMString
<a name="MMString.GetGoString"></a>
func (*MMString) GetGoString
func (s *MMString) GetGoString() string
GetGoString returns go string from manually managed string. CAUTION: You also have to free the MMString
typedarena
import "github.com/joetifa2003/mm-go/typedarena"
typedarena is a growable typed arena that allocates memory in fixed chunks , it's faster that batchallocator but more limited, you can use batchallocator if you want to allocate multiple different types, and you want to use an arena like behavior spanning multiple datastructures (like vector, linkedlist, hashmap etc..), typedarena is much faster when you are only allocating one type.
<details><summary>Example</summary> <p>package main
import (
"fmt"
"github.com/joetifa2003/mm-go/allocator"
"github.com/joetifa2003/mm-go/typedarena"
)
type Entity struct {
VelocityX float32
VelocityY float32
PositionX float32
PositionY float32
}
func main() {
alloc := allocator.NewC()
defer alloc.Destroy()
arena := typedarena.New[Entity](
alloc,
10,
)
defer arena.Free() // frees all memory
for i := 0; i < 10; i++ {
e := arena.Alloc() // *Entity
e.VelocityX = float32(i)
e.VelocityY = float32(i)
e.PositionX = float32(i)
e.PositionY = float32(i)
fmt.Println(e.VelocityX, e.VelocityY, e.PositionX, e.PositionY)
}
entities := arena.AllocMany(10) // allocate slice of 10 entities (cannot exceed 10 here because chunk size is 10 above, this limitation doesn't exist in batchallocator)
_ = entities
}
Output
0 0 0 0
1 1 1 1
2 2 2 2
3 3 3 3
4 4 4 4
5 5 5 5
6 6 6 6
7 7 7 7
8 8 8 8
9 9 9 9
</p>
</details>
Index
<a name="TypedArena"></a>
type TypedArena
TypedArena is a growable typed arena
type TypedArena[T any] struct {
// contains filtered or unexported fields
}
<a name="New"></a>
func New
func New[T any](alloc allocator.Allocator, chunkSize int) *TypedArena[T]
New creates a typed arena with the specified chunk size. a chunk is the the unit of the arena, if T is int for example and the chunk size is 5, then each chunk is going to hold 5 ints. And if the chunk is filled it will allocate another chunk that can hold 5 ints. then you can call FreeArena and it will deallocate all chunks together
<a name="TypedArena[T].Alloc"></a>
func (*TypedArena[T]) Alloc
func (ta *TypedArena[T]) Alloc() *T
Alloc allocates T from the arena
<a name="TypedArena[T].AllocMany"></a>
func (*TypedArena[T]) AllocMany
func (ta *TypedArena[T]) AllocMany(n int) []T
AllocMany allocates n of T and returns a slice representing the heap. CAUTION: don't append to the slice, the purpose of it is to replace pointer arithmetic with slice indexing CAUTION: n cannot exceed chunk size
<a name="TypedArena[T].Free"></a>
func (*TypedArena[T]) Free
func (ta *TypedArena[T]) Free()
Free frees all allocated memory
vector
import "github.com/joetifa2003/mm-go/vector"
<details><summary>Example</summary>
<p>
package main
import (
"fmt"
"github.com/joetifa2003/mm-go/allocator"
"github.com/joetifa2003/mm-go/vector"
)
func main() {
alloc := allocator.NewC()
v := vector.New[int](alloc)
v.Push(1)
v.Push(2)
v.Push(3)
fmt.Println("Length:", v.Len())
for i := 0; i < v.Len(); i++ {
fmt.Println(v.At(i))
}
for _, k := range v.Iter() {
fmt.Println(k)
}
}
Output
Length: 3
1
2
3
1
2
3
</p>
</details>
Index
- type Vector
- func Init[T any](alloc allocator.Allocator, values ...T) *Vector[T]
- func New[T any](aloc allocator.Allocator, args ...int) *Vector[T]
- func (v *Vector[T]) At(idx int) T
- func (v *Vector[T]) AtPtr(idx int) *T
- func (v *Vector[T]) Cap() int
- func (v *Vector[T]) Free()
- func (v *Vector[T]) Iter() iter.Seq2[int, T]
- func (v *Vector[T]) Last() T
- func (v *Vector[T]) Len() int
- func (v *Vector[T]) Pop() T
- func (v *Vector[T]) Push(value T)
- func (v *Vector[T]) RemoveAt(idx int) T
- func (v *Vector[T]) Set(idx int, value T)
- func (v *Vector[T]) Slice() []T
- func (v *Vector[T]) UnsafeAt(idx int) T
<a name="Vector"></a>
type Vector
Vector a contiguous growable array type
type Vector[T any] struct {
// contains filtered or unexported fields
}
<a name="Init"></a>
func Init
func Init[T any](alloc allocator.Allocator, values ...T) *Vector[T]
Init initializes a new vector with the T elements provided and sets it's len and cap to len(values)
<a name="New"></a>
func New
func New[T any](aloc allocator.Allocator, args ...int) *Vector[T]
New creates a new empty vector, if args not provided it will create an empty vector, if only one arg is provided it will init a vector with len and cap equal to the provided arg, if two args are provided it will init a vector with len = args[0] cap = args[1]
<a name="Vector[T].At"></a>
func (*Vector[T]) At
func (v *Vector[T]) At(idx int) T
At gets element T at specified index
<a name="Vector[T].AtPtr"></a>
func (*Vector[T]) AtPtr
func (v *Vector[T]) AtPtr(idx int) *T
AtPtr gets element a pointer of T at specified index
<a name="Vector[T].Cap"></a>
func (*Vector[T]) Cap
func (v *Vector[T]) Cap() int
Cap gets vector capacity (underling memory length).
<a name="Vector[T].Free"></a>
func (*Vector[T]) Free
func (v *Vector[T]) Free()
Free deallocats the vector
<a name="Vector[T].Iter"></a>
func (*Vector[T]) Iter
func (v *Vector[T]) Iter() iter.Seq2[int, T]
Iter iterates over the vector
<a name="Vector[T].Last"></a>
func (*Vector[T]) Last
func (v *Vector[T]) Last() T
Last gets the last element from a vector
<a name="Vector[T].Len"></a>
func (*Vector[T]) Len
func (v *Vector[T]) Len() int
Len gets vector length
<a name="Vector[T].Pop"></a>
func (*Vector[T]) Pop
func (v *Vector[T]) Pop() T
Pop pops value T from the vector and returns it
<a name="Vector[T].Push"></a>
func (*Vector[T]) Push
func (v *Vector[T]) Push(value T)
Push pushes value T to the vector, grows if needed.
<a name="Vector[T].RemoveAt"></a>
func (*Vector[T]) RemoveAt
func (v *Vector[T]) RemoveAt(idx int) T
<a name="Vector[T].Set"></a>
func (*Vector[T]) Set
func (v *Vector[T]) Set(idx int, value T)
Set sets element T at specified index
<a name="Vector[T].Slice"></a>
func (*Vector[T]) Slice
func (v *Vector[T]) Slice() []T
Slice gets a slice representing the vector CAUTION: don't append to this slice, this is only used if you want to loop on the vec elements
<a name="Vector[T].UnsafeAt"></a>
func (*Vector[T]) UnsafeAt
func (v *Vector[T]) UnsafeAt(idx int) T
UnsafeAT gets element T at specified index without bounds checking
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