bufat - options.go

  package bufat
  
  // Options is a type used to specify caching options to the Buffer function.
  type Option func(*opts)
  
  type opts struct {
  	mru       bool
  	chunks    uint64
  	chunkSize int64
  	length    int64
  	offset    int64
  }
  
  // ChunkSize determines the size of each cached block.
  //
  // If unset, or set to a value less-than or equal to 0, the value 4,096 will be
  // used.
  func ChunkSize(size int64) Option {
  	return func(o *opts) {
  		o.chunkSize = size
  	}
  }
  
  // MaxChunks sets the maximum number of chunks that will store i nthe cache
  // before chunks start getting evicted.
  
  // If unset, or set to zero, the value will be 1,024.
  func MaxChunks(chunks uint64) Option {
  	return func(o *opts) {
  		o.chunks = chunks
  	}
  }
  
  // MRU sets the cache to evict the most recently used blocks first.
  func MRU(o *opts) {
  	o.mru = true
  }
  
  // LRU sets the cache to evict the least recently used blocks first.
  func LRU(o *opts) {
  	o.mru = false
  }
  
  // Length is an option to specify that maximum read position of the underlying
  // ReaderAt.
  func Length(l int64) Option {
  	return func(o *opts) {
  		o.length = l
  	}
  }
  
  // Offset sets a reader offset that will be added to the request read position.
  func Offset(offset int64) Option {
  	return func(o *opts) {
  		o.offset = offset
  	}
  }