github.com/m3db/m3@v1.5.0/src/x/cache/cache.go (about)

     1  // Copyright (c) 2020 Uber Technologies, Inc.
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to deal
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     7  // copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    19  // THE SOFTWARE.
    20  
    21  package cache
    22  
    23  import (
    24  	"context"
    25  	"time"
    26  )
    27  
    28  // A LoaderWithTTLFunc is a function for loading entries from a cache, also
    29  // returning an expiration time.
    30  type LoaderWithTTLFunc func(ctx context.Context, key string) (interface{}, time.Time, error)
    31  
    32  // A LoaderFunc is a function for loading entries from a cache.
    33  type LoaderFunc func(ctx context.Context, key string) (interface{}, error)
    34  
    35  // Cache is an interface for caches.
    36  type Cache interface {
    37  	// Put puts a new item in the cache with the default TTL.
    38  	Put(key string, value interface{})
    39  
    40  	// PutWithTTL puts a new item in the cache with a specific TTL.
    41  	PutWithTTL(key string, value interface{}, ttl time.Duration)
    42  
    43  	// Get returns the value associated with the key, optionally
    44  	// loading it if it does not exist or has expired.
    45  	// NB(mmihic): We pass the loader as an argument rather than
    46  	// making it a property of the cache to support access specific
    47  	// loading arguments which might not be bundled into the key.
    48  	Get(ctx context.Context, key string, loader LoaderFunc) (interface{}, error)
    49  
    50  	// GetWithTTL returns the value associated with the key, optionally
    51  	// loading it if it does not exist or has expired, and allowing the
    52  	// loader to return a TTL for the resulting value, overriding the
    53  	// default TTL associated with the cache.
    54  	GetWithTTL(ctx context.Context, key string, loader LoaderWithTTLFunc) (interface{}, error)
    55  }