allocate

Documentation

Index

• Constants
• type Allocator
  • func New[K, D comparable, I Item[K]](nd NextDescriptor[D], config Config) Allocator[K, D, I]
• type Config
  • func DefaultConfig() Config
• type Item
• type Metrics
• type NextDescriptor
• type NextDescriptorInt
  • func (n *NextDescriptorInt) Next() int

Constants

const (
	// DefaultMaxDescriptors is the default maximum number of descriptors.
	DefaultMaxDescriptors = 50
	// DefaultMaxSize is the default maximum size of a descriptor in bytes.
	DefaultMaxSize = 5e8
)

Types

type Allocator

type Allocator[K, D comparable, I Item[K]] interface {
	// Allocate allocates itemDescriptors of a given size to descriptors. Returns a slice of descriptor keys.
	Allocate(items ...I) []D
}

Allocator is used to allocate items to a set of descriptors. A descriptor can represent a file, buffer (essentially anything assigned with a maximum size).

Type Arguments:

K - The type of the items key. D - The type of the descriptors key.

Implementation Details:

The implementation of Allocator provided in this package optimizes for: sequential allocation of items with the same key (i.e. all items with the key "hello" go to their own file (if possible)). It uses a simple set of rules:

1. Allocate the item to the descriptor it was allocated to previously.
2. If the item is not allocated OR the size of the descriptor exceeds the size set in Config.MaxSize, then allocate the item to the next AVAILABLE descriptor.

Available Means:

A. A completely NEW descriptor if config.MaxDescriptors has not been reached.
OR
B. The descriptor with the lowest size if config.MaxDescriptors has been reached.

func New

func New[K, D comparable, I Item[K]](nd NextDescriptor[D], config Config) Allocator[K, D, I]

type Config

type Config struct {
	// MaxDescriptors is the maximum number of concurrent descriptors that can be allocated at once.
	// If this value is 0, the default value of DefaultMaxDescriptors is used.
	MaxDescriptors int
	// MaxSize is the maximum size of a descriptor in bytes. If this value is 0, the default value of
	// DefaultMaxSize is used.
	MaxSize telem.Size
	// Experiment is the experiment that Allocate will use to record its metrics.
	Experiment alamos.Experiment
}

func DefaultConfig

func DefaultConfig() Config

DefaultConfig returns the default configuration for the Allocator.

type Item

type Item[K comparable] interface {
	// Key returns the key of the item.
	Key() K
	// Size returns the size of the item.
	Size() telem.Size
}

type Metrics

type Metrics struct {
	// Allocate counts the number of keys allocated by the Allocator and the average time to allocate a key.
	Allocate alamos.Duration
}

type NextDescriptor

type NextDescriptor[D comparable] interface {
	Next() D
}

NextDescriptor returns a unique descriptor key that represents the next descriptor.

type NextDescriptorInt

type NextDescriptorInt struct {
	// contains filtered or unexported fields
}

func (*NextDescriptorInt) Next

func (n *NextDescriptorInt) Next() int