gotosocial/internal/cache/wrappers.go
kim adf345f1ec
[chore] bump go structr cache version -> v0.6.0 (#2773)
* update go-structr library -> v0.6.0, add necessary wrapping types + code changes to support these changes

* update readme with go-structr package changes

* improved wrapping of the SliceCache type

* add code comments for the cache wrapper types

* remove test.out 😇

---------

Co-authored-by: tobi <31960611+tsmethurst@users.noreply.github.com>
2024-04-02 12:03:40 +02:00

214 lines
6.8 KiB
Go

// GoToSocial
// Copyright (C) GoToSocial Authors admin@gotosocial.org
// SPDX-License-Identifier: AGPL-3.0-or-later
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package cache
import (
"slices"
"codeberg.org/gruf/go-cache/v3/simple"
"codeberg.org/gruf/go-structr"
)
// SliceCache wraps a simple.Cache to provide simple loader-callback
// functions for fetching + caching slices of objects (e.g. IDs).
type SliceCache[T any] struct {
cache simple.Cache[string, []T]
}
// Init initializes the cache with given length + capacity.
func (c *SliceCache[T]) Init(len, cap int) {
c.cache = simple.Cache[string, []T]{}
c.cache.Init(len, cap)
}
// Load will attempt to load an existing slice from cache for key, else calling load function and caching the result.
func (c *SliceCache[T]) Load(key string, load func() ([]T, error)) ([]T, error) {
// Look for cached values.
data, ok := c.cache.Get(key)
if !ok {
var err error
// Not cached, load!
data, err = load()
if err != nil {
return nil, err
}
// Store the data.
c.cache.Set(key, data)
}
// Return data clone for safety.
return slices.Clone(data), nil
}
// Invalidate: see simple.Cache{}.InvalidateAll().
func (c *SliceCache[T]) Invalidate(keys ...string) {
_ = c.cache.InvalidateAll(keys...)
}
// Trim: see simple.Cache{}.Trim().
func (c *SliceCache[T]) Trim(perc float64) {
c.cache.Trim(perc)
}
// Clear: see simple.Cache{}.Clear().
func (c *SliceCache[T]) Clear() {
c.cache.Clear()
}
// Len: see simple.Cache{}.Len().
func (c *SliceCache[T]) Len() int {
return c.cache.Len()
}
// Cap: see simple.Cache{}.Cap().
func (c *SliceCache[T]) Cap() int {
return c.cache.Cap()
}
// StructCache wraps a structr.Cache{} to simple index caching
// by name (also to ease update to library version that introduced
// this). (in the future it may be worth embedding these indexes by
// name under the main database caches struct which would reduce
// time required to access cached values).
type StructCache[StructType any] struct {
cache structr.Cache[StructType]
index map[string]*structr.Index
}
// Init initializes the cache with given structr.CacheConfig{}.
func (c *StructCache[T]) Init(config structr.CacheConfig[T]) {
c.index = make(map[string]*structr.Index, len(config.Indices))
c.cache = structr.Cache[T]{}
c.cache.Init(config)
for _, cfg := range config.Indices {
c.index[cfg.Fields] = c.cache.Index(cfg.Fields)
}
}
// GetOne calls structr.Cache{}.GetOne(), using a cached structr.Index{} by 'index' name.
// Note: this also handles conversion of the untyped (any) keys to structr.Key{} via structr.Index{}.
func (c *StructCache[T]) GetOne(index string, key ...any) (T, bool) {
i := c.index[index]
return c.cache.GetOne(i, i.Key(key...))
}
// Get calls structr.Cache{}.Get(), using a cached structr.Index{} by 'index' name.
// Note: this also handles conversion of the untyped (any) keys to structr.Key{} via structr.Index{}.
func (c *StructCache[T]) Get(index string, keys ...[]any) []T {
i := c.index[index]
return c.cache.Get(i, i.Keys(keys...)...)
}
// Put: see structr.Cache{}.Put().
func (c *StructCache[T]) Put(values ...T) {
c.cache.Put(values...)
}
// LoadOne calls structr.Cache{}.LoadOne(), using a cached structr.Index{} by 'index' name.
// Note: this also handles conversion of the untyped (any) keys to structr.Key{} via structr.Index{}.
func (c *StructCache[T]) LoadOne(index string, load func() (T, error), key ...any) (T, error) {
i := c.index[index]
return c.cache.LoadOne(i, i.Key(key...), load)
}
// LoadIDs calls structr.Cache{}.Load(), using a cached structr.Index{} by 'index' name. Note: this also handles
// conversion of the ID strings to structr.Key{} via structr.Index{}. Strong typing is used for caller convenience.
//
// If you need to load multiple cache keys other than by ID strings, please create another convenience wrapper.
func (c *StructCache[T]) LoadIDs(index string, ids []string, load func([]string) ([]T, error)) ([]T, error) {
i := c.index[index]
if i == nil {
// we only perform this check here as
// we're going to use the index before
// passing it to cache in main .Load().
panic("missing index for cache type")
}
// Generate cache keys for ID types.
keys := make([]structr.Key, len(ids))
for x, id := range ids {
keys[x] = i.Key(id)
}
// Pass loader callback with wrapper onto main cache load function.
return c.cache.Load(i, keys, func(uncached []structr.Key) ([]T, error) {
uncachedIDs := make([]string, len(uncached))
for i := range uncached {
uncachedIDs[i] = uncached[i].Values()[0].(string)
}
return load(uncachedIDs)
})
}
// Store: see structr.Cache{}.Store().
func (c *StructCache[T]) Store(value T, store func() error) error {
return c.cache.Store(value, store)
}
// Invalidate calls structr.Cache{}.Invalidate(), using a cached structr.Index{} by 'index' name.
// Note: this also handles conversion of the untyped (any) keys to structr.Key{} via structr.Index{}.
func (c *StructCache[T]) Invalidate(index string, key ...any) {
i := c.index[index]
c.cache.Invalidate(i, i.Key(key...))
}
// InvalidateIDs calls structr.Cache{}.Invalidate(), using a cached structr.Index{} by 'index' name. Note: this also
// handles conversion of the ID strings to structr.Key{} via structr.Index{}. Strong typing is used for caller convenience.
//
// If you need to invalidate multiple cache keys other than by ID strings, please create another convenience wrapper.
func (c *StructCache[T]) InvalidateIDs(index string, ids []string) {
i := c.index[index]
if i == nil {
// we only perform this check here as
// we're going to use the index before
// passing it to cache in main .Load().
panic("missing index for cache type")
}
// Generate cache keys for ID types.
keys := make([]structr.Key, len(ids))
for x, id := range ids {
keys[x] = i.Key(id)
}
// Pass to main invalidate func.
c.cache.Invalidate(i, keys...)
}
// Trim: see structr.Cache{}.Trim().
func (c *StructCache[T]) Trim(perc float64) {
c.cache.Trim(perc)
}
// Clear: see structr.Cache{}.Clear().
func (c *StructCache[T]) Clear() {
c.cache.Clear()
}
// Len: see structr.Cache{}.Len().
func (c *StructCache[T]) Len() int {
return c.cache.Len()
}
// Cap: see structr.Cache{}.Cap().
func (c *StructCache[T]) Cap() int {
return c.cache.Cap()
}