refine docs.

This commit is contained in:
Raúl Kripalani 2021-01-29 23:24:44 +00:00
parent d1104fec4c
commit 35d1e3d1e0
3 changed files with 23 additions and 22 deletions

View File

@ -1,17 +1,3 @@
// blockstore contains all the basic blockstore constructors used by lotus. Any
// blockstores not ultimately constructed out of the building blocks in this
// package may not work properly.
//
// * This package correctly wraps blockstores with the IdBlockstore. This blockstore:
// * Filters out all puts for blocks with CIDs using the "identity" hash function.
// * Extracts inlined blocks from CIDs using the identity hash function and
// returns them on get/has, ignoring the contents of the blockstore.
// * In the future, this package may enforce additional restrictions on block
// sizes, CID validity, etc.
//
// To make auditing for misuse of blockstores tractable, this package re-exports
// parts of the go-ipfs-blockstore package such that no other package needs to
// import it directly.
package blockstore
import (
@ -40,6 +26,10 @@ type BasicBlockstore = blockstore.Blockstore
type Viewer = blockstore.Viewer
// WrapIDStore wraps the underlying blockstore in an "identity" blockstore.
// The ID store filters out all puts for blocks with CIDs using the "identity"
// hash function. It also extracts inlined blocks from CIDs using the identity
// hash function and returns them on get/has, ignoring the contents of the
// blockstore.
func WrapIDStore(bstore blockstore.Blockstore) Blockstore {
return blockstore.NewIdStore(bstore).(Blockstore)
}

9
blockstore/doc.go Normal file
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@ -0,0 +1,9 @@
// Package blockstore and subpackages contain most of the blockstore
// implementations used by Lotus.
//
// Blockstores not ultimately constructed out of the building blocks in this
// package may not work properly.
//
// This package re-exports parts of the go-ipfs-blockstore package such that
// no other package needs to import it directly, for ergonomics and traceability.
package blockstore

View File

@ -14,17 +14,19 @@ import (
type FallbackStore struct {
Blockstore
fallbackGetBlock func(context.Context, cid.Cid) (blocks.Block, error)
lk sync.RWMutex
// missFn is the function that will be invoked on a local miss to pull the
// block from elsewhere.
missFn func(context.Context, cid.Cid) (blocks.Block, error)
}
var _ Blockstore = (*FallbackStore)(nil)
func (fbs *FallbackStore) SetFallback(fg func(context.Context, cid.Cid) (blocks.Block, error)) {
func (fbs *FallbackStore) SetFallback(missFn func(context.Context, cid.Cid) (blocks.Block, error)) {
fbs.lk.Lock()
defer fbs.lk.Unlock()
fbs.fallbackGetBlock = fg
fbs.missFn = missFn
}
func (fbs *FallbackStore) getFallback(c cid.Cid) (blocks.Block, error) {
@ -32,15 +34,15 @@ func (fbs *FallbackStore) getFallback(c cid.Cid) (blocks.Block, error) {
fbs.lk.RLock()
defer fbs.lk.RUnlock()
if fbs.fallbackGetBlock == nil {
if fbs.missFn == nil {
// FallbackStore wasn't configured yet (chainstore/bitswap aren't up yet)
// Wait for a bit and retry
fbs.lk.RUnlock()
time.Sleep(5 * time.Second)
fbs.lk.RLock()
if fbs.fallbackGetBlock == nil {
log.Errorw("fallbackstore: fallbackGetBlock not configured yet")
if fbs.missFn == nil {
log.Errorw("fallbackstore: missFn not configured yet")
return nil, ErrNotFound
}
}
@ -48,7 +50,7 @@ func (fbs *FallbackStore) getFallback(c cid.Cid) (blocks.Block, error) {
ctx, cancel := context.WithTimeout(context.TODO(), 120*time.Second)
defer cancel()
b, err := fbs.fallbackGetBlock(ctx, c)
b, err := fbs.missFn(ctx, c)
if err != nil {
return nil, err
}