Migrate pkg/lazy => pkglib/{lazy,lifetime}
This commit is contained in:
Tom Wiesing
parent
c3ca8e2974
commit
5e89fadeeb
21 changed files with 54 additions and 612 deletions
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@ -6,8 +6,8 @@ import (
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"sync"
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"time"
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"github.com/FAU-CDI/wisski-distillery/pkg/lazy"
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"github.com/gorilla/websocket"
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"github.com/tkw1536/pkglib/lazy"
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)
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// WebSocket implements serving a WebSocket
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@ -1,50 +0,0 @@
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package lazy
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import (
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"sync"
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)
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// Lazy holds a lazily initialized value of T.
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// A non-zero lazy must not be copied after first use.
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type Lazy[T any] struct {
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once sync.Once
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m sync.RWMutex // m protects setting the value of this T
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value T // the stored value
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}
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// Get returns the value associated with this Lazy.
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//
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// If no other call to Get has started or completed an initialization, calls init to initialize the value.
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// A nil init function indicates to store the zero value of T.
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// If an initialization has been previously completed, the previously stored value is returned.
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//
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// If init panics, the initization is considered to be completed.
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// Future calls to Get() do not invoke init, and the zero value of T is returned.
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//
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// Get may safely be called concurrently.
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func (lazy *Lazy[T]) Get(init func() T) T {
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lazy.m.RLock()
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defer lazy.m.RUnlock()
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lazy.once.Do(func() {
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if init != nil {
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lazy.value = init()
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}
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})
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return lazy.value
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}
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// Set atomically sets the value of this lazy.
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// Any previously set value will be overwritten.
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// Future calls to [Get] will not invoke init.
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//
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// It may be called concurrently with calls to [Get].
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func (lazy *Lazy[T]) Set(value T) {
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lazy.m.Lock()
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defer lazy.m.Unlock()
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lazy.value = value
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lazy.once.Do(func() {})
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}
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@ -1,31 +0,0 @@
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package lazy
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import "fmt"
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func ExampleLazy() {
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var lazy Lazy[int]
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// the first invocation to lazy will be called and set the value
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fmt.Println(lazy.Get(func() int { return 42 }))
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// the second invocation will not call init again, using the first value
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fmt.Println(lazy.Get(func() int { return 43 }))
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// Set can be used to set a specific value
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lazy.Set(0)
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fmt.Println(lazy.Get(func() int { panic("never called") }))
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// Output: 42
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// 42
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// 0
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}
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func ExampleLazy_nil() {
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var lazy Lazy[int]
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// passing nil as the initialization function causes the zero value to be set
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fmt.Println(lazy.Get(nil))
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// Output: 0
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}
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189
pkg/lazy/pool.go
189
pkg/lazy/pool.go
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@ -1,189 +0,0 @@
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package lazy
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import (
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"reflect"
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"github.com/tkw1536/pkglib/reflectx"
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)
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// Pool represents a pool of laziliy initialized and potentially referencing Component instances.
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//
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// Component must be an interface type, that should be implemented by various pointers to structs.
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// Components may reference each other, even circularly.
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//
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// Each type of struct is considered a singleton an initialized only once.
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//
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// See [Pool.All], [ExportComponents] and [ExportComponent].
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//
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// The zero value is ready to use.
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type Pool[Component any, InitParams any] struct {
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// Init is called on every component to be initialized.
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Init func(Component, InitParams) Component
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// Analytics are written on the first retrieval operation on this Pool.
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//
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// Contains all groups and structs that are referenced during initialization.
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// To add extra groups, call RegisterPoolGroup.
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Analytics PoolAnalytics
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extraGroups []reflect.Type
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all Lazy[[]Component]
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}
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// RegisterPoolGroup registers the given group type to be added to the pools' analytics.
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//
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// Only groups not referenced during initialization need to be registered explicitly.
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func RegisterPoolGroup[Group any, Component any, InitParams any](p *Pool[Component, InitParams]) {
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p.extraGroups = append(p.extraGroups, reflectx.TypeOf[Group]())
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}
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// All initializes or returns all components stored in this pool.
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//
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// The All function should return an array of calls to [Make] with the provided context.
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// Multiple calls to the this method return the same return value.
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func (p *Pool[Component, InitParams]) All(Params InitParams, All func(context *PoolContext[Component]) []Component) []Component {
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return p.all.Get(func() []Component {
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// create a new context
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context := &PoolContext[Component]{
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all: All,
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init: func(c Component) Component {
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if p.Init == nil {
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return c
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}
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return p.Init(c, Params)
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},
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metaCache: make(map[reflect.Type]meta[Component]),
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cache: make(map[string]Component),
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}
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// and process them all
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all := context.all(context)
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context.process(all)
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// write out analytics
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context.anal(&p.Analytics, p.extraGroups)
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return all
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})
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}
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// PoolContext is a context used during [Make].
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type PoolContext[Component any] struct {
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init func(Component) Component // initializes a new component
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all func(context *PoolContext[Component]) []Component // initializes all components
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metaCache map[reflect.Type]meta[Component]
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cache map[string]Component // cached components
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queue []delayedInit[Component] // init queue
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}
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type delayedInit[Component any] struct {
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meta meta[Component]
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value reflect.Value
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}
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// Process processes all components in the queue
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func (p *PoolContext[Component]) process(all []Component) {
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index := 0
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for len(p.queue) > index {
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p.queue[index].Run(all)
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index++
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}
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p.queue = nil
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}
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func (di *delayedInit[Component]) Run(all []Component) {
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di.meta.InitComponent(di.value, all)
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}
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// Make creates or returns a cached component of the given Context.
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//
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// Components are initialized by first
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// Then all component-like fields of fields are filled with their appropriate components.
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//
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// A component-like field has one of the following types:
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//
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// - A pointer to a struct type that implements component
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// - A slice type of an interface type that implements component
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//
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// Such component-like fields are only initialized if one of the following conditions are met:
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//
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// - The field has a tag 'auto' with the value `true`
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// - The field lives inside a struct field named `Dependencies`
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//
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// These fields are initialized in an undefined order during initialization.
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// The init function may not rely on these existing.
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// Furthermore, the init function may not cause other components to be initialized.
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//
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// The init function may be nil, indicating that no additional initialization is required.
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func Make[Component any, ConcreteComponent any](context *PoolContext[Component], init func(component ConcreteComponent)) ConcreteComponent {
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// get a description of the type
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cd := getMeta[Component, ConcreteComponent](context.metaCache)
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// if an instance already exists, return it!
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if instance, ok := context.cache[cd.Name]; ok {
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return any(instance).(ConcreteComponent)
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}
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// create a fresh new instance and store it in the cache
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context.cache[cd.Name] = context.init(cd.New())
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instance := any(context.cache[cd.Name]).(ConcreteComponent)
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// call the passed init function
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if init != nil {
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init(instance)
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}
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// and queue it up
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if cd.NeedsInitComponent() {
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context.queue = append(context.queue, delayedInit[Component]{
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meta: cd,
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value: reflect.ValueOf(instance),
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})
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}
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return instance
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}
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//
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// PUBLIC FUNCTIONS
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//
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// ExportComponents exports all components that are a ConcreteComponentType from the pool.
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//
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// All should be the function of the core that initializes all components.
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// All should only make calls to [InitComponent].
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func ExportComponents[Component any, InitParams any, ConcreteComponentType any](
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p *Pool[Component, InitParams],
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Params InitParams,
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All func(context *PoolContext[Component]) []Component,
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) []ConcreteComponentType {
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components := p.All(Params, All)
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results := make([]ConcreteComponentType, 0, len(components))
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for _, comp := range components {
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if cc, ok := any(comp).(ConcreteComponentType); ok {
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results = append(results, cc)
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}
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}
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return results
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}
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// ExportComponent exports the first component that is a ConcreteComponent from the pool.
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//
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// All should be the function of the core that initializes all components.
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// All should only make calls to [InitComponent].
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func ExportComponent[Component any, InitParams any, ConcreteComponentType any](
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pool *Pool[Component, InitParams],
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Params InitParams,
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All func(context *PoolContext[Component]) []Component,
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) ConcreteComponentType {
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components := pool.All(Params, All)
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for _, comp := range components {
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if cc, ok := any(comp).(ConcreteComponentType); ok {
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return cc
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}
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}
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panic("ExportComponent: Attempted to export unregistered component")
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}
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@ -1,112 +0,0 @@
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package lazy
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import (
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"reflect"
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"github.com/tkw1536/pkglib/collection"
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"golang.org/x/exp/slices"
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)
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type PoolAnalytics struct {
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Components map[string]*PoolAnalyticsComponent
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Groups map[string]*PoolAnalyticsGroup
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}
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type PoolAnalyticsComponent struct {
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Type string // Type name
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Groups []string // groups this is contained in
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CFields map[string]string // fields with type C for which C implements component
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IFields map[string]string // fields []I where I is an interface that implements component
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DCFields map[string]string // fields of the auto field with type C for which C implements component
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DIFields map[string]string // fields of the auto field []I where I is an interface that implements component
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Methods map[string]string // Method signatures of type
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}
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type PoolAnalyticsGroup struct {
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Type string // Type name
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Components []string // Components of this Type
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Methods map[string]string // Method signatures of this interface
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}
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// anal writes analytics about this context to anal
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func (context *PoolContext[Component]) anal(anal *PoolAnalytics, groups []reflect.Type) {
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anal.Components = make(map[string]*PoolAnalyticsComponent, len(context.metaCache))
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anal.Groups = make(map[string]*PoolAnalyticsGroup)
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// collect all the pointers, and setup the anal.Components map!
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tpPointers := make([]reflect.Type, 0, len(context.metaCache))
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for _, meta := range context.metaCache {
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tp := reflect.PointerTo(meta.Elem)
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tpPointers = append(tpPointers, tp)
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mcount := tp.NumMethod()
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anal.Components[meta.Name] = &PoolAnalyticsComponent{
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Groups: make([]string, 0),
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Methods: make(map[string]string, mcount),
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}
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for i := 0; i < mcount; i++ {
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method := tp.Method(i)
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anal.Components[meta.Name].Methods[method.Name] = method.Type.String()
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}
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}
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// collect interfaces to analyze
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ifaces := make([]reflect.Type, len(groups))
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copy(ifaces, groups)
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// take all of the components out of the cache
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for _, meta := range context.metaCache {
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anal.Components[meta.Name].Type = meta.Name
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anal.Components[meta.Name].CFields = collection.MapValues(meta.CFields, func(key string, tp reflect.Type) string {
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return nameOf(tp.Elem())
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})
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anal.Components[meta.Name].DCFields = collection.MapValues(meta.DCFields, func(key string, tp reflect.Type) string {
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return nameOf(tp.Elem())
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})
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anal.Components[meta.Name].IFields = collection.MapValues(meta.IFields, func(key string, iface reflect.Type) string {
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ifaces = append(ifaces, iface)
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return nameOf(iface)
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})
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anal.Components[meta.Name].DIFields = collection.MapValues(meta.DIFields, func(key string, iface reflect.Type) string {
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ifaces = append(ifaces, iface)
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return nameOf(iface)
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})
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}
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// and analyze all ifaces
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for _, iface := range ifaces {
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name := nameOf(iface)
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if _, ok := anal.Groups[name]; ok {
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continue
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}
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types := collection.FilterClone(tpPointers, func(tp reflect.Type) bool {
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return tp.AssignableTo(iface)
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})
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anal.Groups[name] = &PoolAnalyticsGroup{
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Type: name,
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Components: collection.MapSlice(types, func(tp reflect.Type) string {
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cname := nameOf(tp.Elem())
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anal.Components[cname].Groups = append(anal.Components[cname].Groups, name)
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return cname
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}),
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}
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mcount := iface.NumMethod()
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anal.Groups[name].Methods = make(map[string]string, mcount)
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for i := 0; i < mcount; i++ {
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method := iface.Method(i)
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anal.Groups[name].Methods[method.Name] = method.Type.String()
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}
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}
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for _, comp := range anal.Components {
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slices.Sort(comp.Groups)
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}
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}
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@ -1,177 +0,0 @@
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package lazy
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import (
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"reflect"
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"github.com/tkw1536/pkglib/collection"
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"github.com/tkw1536/pkglib/reflectx"
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)
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// getMeta gets the component belonging to a component type
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func getMeta[Component any, ConcreteComponent any](cache map[reflect.Type]meta[Component]) meta[Component] {
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tp := reflectx.TypeOf[ConcreteComponent]()
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// we already have a m => return it
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if m, ok := cache[tp]; ok {
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return m
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}
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// create a new m
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var m meta[Component]
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m.init(tp)
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// store it in the cache
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cache[tp] = m
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return m
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}
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// meta stores meta-information about a specific component
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type meta[Component any] struct {
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Name string // the type name of this component
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Elem reflect.Type // the element type of the component
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CFields map[string]reflect.Type // fields with type C for which C implements component
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IFields map[string]reflect.Type // fields []I where I is an interface that implements component
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DCFields map[string]reflect.Type // fields with type C for which C inside auto field which implement component
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DIFields map[string]reflect.Type // fields []I where I is an interface inside auto field that implements component
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}
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// init initializes this meta
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func (m *meta[Component]) init(tp reflect.Type) {
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var component = reflectx.TypeOf[Component]()
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if tp.Kind() != reflect.Pointer && tp.Elem().Kind() != reflect.Struct {
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panic("GetMeta: Type (" + tp.String() + ") must be backed by a pointer to slice")
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}
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m.Elem = tp.Elem()
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m.Name = nameOf(m.Elem)
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m.CFields = make(map[string]reflect.Type)
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m.IFields = make(map[string]reflect.Type)
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scanForFields(component, m.Name, m.Elem, false, m.CFields, m.IFields)
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// check if we have a dependencies field of struct type
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dependenciesField, ok := m.Elem.FieldByName(dependencies)
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if !ok {
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return
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}
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if dependenciesField.Type.Kind() != reflect.Struct {
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panic("GetMeta: " + dependencies + " field (" + m.Name + ") is not a struct")
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}
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// and initialize the type map of the given map
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m.DCFields = make(map[string]reflect.Type)
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m.DIFields = make(map[string]reflect.Type)
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scanForFields(component, m.Name, dependenciesField.Type, true, m.DCFields, m.DIFields)
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}
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// scanForFields scans the structtype for fields of component-like fields.
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// they are then writen to the cFields and iFields maps.
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// inDependenciesStruct indicates if we are inside a dependency struct
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func scanForFields(component reflect.Type, elem string, structType reflect.Type, inDependenciesStruct bool, cFields map[string]reflect.Type, iFields map[string]reflect.Type) {
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count := structType.NumField()
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for i := 0; i < count; i++ {
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field := structType.Field(i)
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if !inDependenciesStruct && field.Tag.Get("auto") != "true" {
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continue
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}
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if inDependenciesStruct && field.Tag != "" {
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panic("GetMeta: " + dependencies + " field (" + elem + ") contains field (" + field.Name + ") with tag")
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}
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tp := field.Type
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name := field.Name
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switch {
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case implementsComponent(component, tp):
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cFields[name] = tp
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case implementsSlice(component, tp):
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iFields[name] = tp.Elem()
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case inDependenciesStruct:
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panic("GetMeta: " + dependencies + " field (" + elem + ") contains non-auto fields")
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}
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}
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||||
}
|
||||
|
||||
func implementsComponent(component reflect.Type, tp reflect.Type) bool {
|
||||
return tp.Implements(component) && tp.Kind() == reflect.Pointer && tp.Elem().Kind() == reflect.Struct
|
||||
}
|
||||
|
||||
func implementsSlice(component reflect.Type, tp reflect.Type) bool {
|
||||
return tp.Kind() == reflect.Slice && tp.Elem().Kind() == reflect.Interface && tp.Elem().Implements(component)
|
||||
}
|
||||
|
||||
func nameOf(tp reflect.Type) string {
|
||||
return tp.PkgPath() + "." + tp.Name()
|
||||
}
|
||||
|
||||
// New creates a new ComponentDescription
|
||||
func (m meta[Component]) New() Component {
|
||||
return reflect.New(m.Elem).Interface().(Component)
|
||||
}
|
||||
|
||||
// NeedsInitComponent
|
||||
func (m meta[Component]) NeedsInitComponent() bool {
|
||||
return len(m.CFields) > 0 || len(m.IFields) > 0 || len(m.DCFields) > 0 || len(m.DIFields) > 0
|
||||
}
|
||||
|
||||
// name of the dependencies field
|
||||
const dependencies = "Dependencies"
|
||||
|
||||
// InitComponent sets up the fields of the given instance of a component.
|
||||
func (m meta[Component]) InitComponent(instance reflect.Value, all []Component) {
|
||||
elem := instance.Elem()
|
||||
dependenciesElem := elem.FieldByName(dependencies)
|
||||
|
||||
// assign the component fields
|
||||
for field, eType := range m.CFields {
|
||||
c := collection.First(all, func(c Component) bool {
|
||||
return reflect.TypeOf(c).AssignableTo(eType)
|
||||
})
|
||||
|
||||
field := elem.FieldByName(field)
|
||||
field.Set(reflect.ValueOf(c))
|
||||
}
|
||||
for field, eType := range m.DCFields {
|
||||
c := collection.First(all, func(c Component) bool {
|
||||
return reflect.TypeOf(c).AssignableTo(eType)
|
||||
})
|
||||
|
||||
field := dependenciesElem.FieldByName(field)
|
||||
field.Set(reflect.ValueOf(c))
|
||||
}
|
||||
|
||||
// assign the interface subtypes
|
||||
registryR := reflect.ValueOf(all)
|
||||
for field, eType := range m.IFields {
|
||||
cs := filterSubtype(registryR, eType)
|
||||
field := elem.FieldByName(field)
|
||||
field.Set(cs)
|
||||
}
|
||||
for field, eType := range m.DIFields {
|
||||
cs := filterSubtype(registryR, eType)
|
||||
field := dependenciesElem.FieldByName(field)
|
||||
field.Set(cs)
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
// filterSubtype filters the slice of type []S into a slice of type []iface.
|
||||
// S and I must be interface types.
|
||||
func filterSubtype(sliceS reflect.Value, iface reflect.Type) reflect.Value {
|
||||
len := sliceS.Len()
|
||||
|
||||
// convert each element
|
||||
result := reflect.MakeSlice(reflect.SliceOf(iface), 0, len)
|
||||
for i := 0; i < len; i++ {
|
||||
element := sliceS.Index(i)
|
||||
if element.Elem().Type().Implements(iface) {
|
||||
result = reflect.Append(result, element.Elem().Convert(iface))
|
||||
}
|
||||
}
|
||||
return result
|
||||
}
|
||||
Loading…
Add table
Add a link
Reference in a new issue