ipld-eth-server/vendor/github.com/ipfs/go-ipfs-blockstore/caching.go

56 lines
1.5 KiB
Go

package blockstore
import (
"context"
"errors"
metrics "github.com/ipfs/go-metrics-interface"
)
// CacheOpts wraps options for CachedBlockStore().
// Next to each option is it aproximate memory usage per unit
type CacheOpts struct {
HasBloomFilterSize int // 1 byte
HasBloomFilterHashes int // No size, 7 is usually best, consult bloom papers
HasARCCacheSize int // 32 bytes
}
// DefaultCacheOpts returns a CacheOpts initialized with default values.
func DefaultCacheOpts() CacheOpts {
return CacheOpts{
HasBloomFilterSize: 512 << 10,
HasBloomFilterHashes: 7,
HasARCCacheSize: 64 << 10,
}
}
// CachedBlockstore returns a blockstore wrapped in an ARCCache and
// then in a bloom filter cache, if the options indicate it.
func CachedBlockstore(
ctx context.Context,
bs Blockstore,
opts CacheOpts) (cbs Blockstore, err error) {
cbs = bs
if opts.HasBloomFilterSize < 0 || opts.HasBloomFilterHashes < 0 ||
opts.HasARCCacheSize < 0 {
return nil, errors.New("all options for cache need to be greater than zero")
}
if opts.HasBloomFilterSize != 0 && opts.HasBloomFilterHashes == 0 {
return nil, errors.New("bloom filter hash count can't be 0 when there is size set")
}
ctx = metrics.CtxSubScope(ctx, "bs.cache")
if opts.HasARCCacheSize > 0 {
cbs, err = newARCCachedBS(ctx, cbs, opts.HasARCCacheSize)
}
if opts.HasBloomFilterSize != 0 {
// *8 because of bytes to bits conversion
cbs, err = bloomCached(ctx, cbs, opts.HasBloomFilterSize*8, opts.HasBloomFilterHashes)
}
return cbs, err
}