@ -57,7 +57,7 @@ func init() {
} }
} }
// NewHandler creates a new Mutable Resource API
// NewHandler creates a new Swarm Feeds API
func NewHandler ( params * HandlerParams ) * Handler { func NewHandler ( params * HandlerParams ) * Handler {
fh := & Handler { fh := & Handler {
cache : make ( map [ uint64 ] * cacheEntry ) , cache : make ( map [ uint64 ] * cacheEntry ) ,
@ -74,13 +74,13 @@ func NewHandler(params *HandlerParams) *Handler {
return fh return fh
} }
// SetStore sets the store backend for the Mutable Resource API
// SetStore sets the store backend for the Swarm Feeds API
func ( h * Handler ) SetStore ( store * storage . NetStore ) { func ( h * Handler ) SetStore ( store * storage . NetStore ) {
h . chunkStore = store h . chunkStore = store
} }
// Validate is a chunk validation method
// Validate is a chunk validation method
// If it looks like a resource update, the chunk address is checked against the userAddr of the update's signature
// If it looks like a feed update, the chunk address is checked against the userAddr of the update's signature
// It implements the storage.ChunkValidator interface
// It implements the storage.ChunkValidator interface
func ( h * Handler ) Validate ( chunkAddr storage . Address , data [ ] byte ) bool { func ( h * Handler ) Validate ( chunkAddr storage . Address , data [ ] byte ) bool {
dataLength := len ( data ) dataLength := len ( data )
@ -89,7 +89,7 @@ func (h *Handler) Validate(chunkAddr storage.Address, data []byte) bool {
} }
// check if it is a properly formatted update chunk with
// check if it is a properly formatted update chunk with
// valid signature and proof of ownership of the resource it is trying
// valid signature and proof of ownership of the feed it is trying
// to update
// to update
// First, deserialize the chunk
// First, deserialize the chunk
@ -99,9 +99,9 @@ func (h *Handler) Validate(chunkAddr storage.Address, data []byte) bool {
return false return false
} }
// Verify signatures and that the signer actually owns the resource
// Verify signatures and that the signer actually owns the feed
// If it fails, it means either the signature is not valid, data is corrupted
// If it fails, it means either the signature is not valid, data is corrupted
// or someone is trying to update someone else's resource .
// or someone is trying to update someone else's feed .
if err := r . Verify ( ) ; err != nil { if err := r . Verify ( ) ; err != nil {
log . Debug ( "Invalid feed update signature" , "err" , err ) log . Debug ( "Invalid feed update signature" , "err" , err )
return false return false
@ -110,14 +110,14 @@ func (h *Handler) Validate(chunkAddr storage.Address, data []byte) bool {
return true return true
} }
// GetContent retrieves the data payload of the last synced update of the Mutable Resource
// GetContent retrieves the data payload of the last synced update of the Feed
func ( h * Handler ) GetContent ( feed * Feed ) ( storage . Address , [ ] byte , error ) { func ( h * Handler ) GetContent ( feed * Feed ) ( storage . Address , [ ] byte , error ) {
if feed == nil { if feed == nil {
return nil , nil , NewError ( ErrInvalidValue , "view is nil" ) return nil , nil , NewError ( ErrInvalidValue , "feed is nil" )
} }
feedUpdate := h . get ( feed ) feedUpdate := h . get ( feed )
if feedUpdate == nil { if feedUpdate == nil {
return nil , nil , NewError ( ErrNotFound , "resource does not exist " ) return nil , nil , NewError ( ErrNotFound , "feed update not cached " )
} }
return feedUpdate . lastKey , feedUpdate . data , nil return feedUpdate . lastKey , feedUpdate . data , nil
} }
@ -142,7 +142,7 @@ func (h *Handler) NewRequest(ctx context.Context, feed *Feed) (request *Request,
return nil , err return nil , err
} }
// not finding updates means that there is a network error
// not finding updates means that there is a network error
// or that the resource really does not have updates
// or that the feed really does not have updates
} }
request . Feed = * feed request . Feed = * feed
@ -157,13 +157,10 @@ func (h *Handler) NewRequest(ctx context.Context, feed *Feed) (request *Request,
return request , nil return request , nil
} }
// Lookup retrieves a specific or latest version of the resource
// Lookup retrieves a specific or latest feed update
// Lookup works differently depending on the configuration of `ID`
// Lookup works differently depending on the configuration of `query`
// See the `ID` documentation and helper functions:
// See the `query` documentation and helper functions:
// `LookupLatest` and `LookupBefore`
// `NewQueryLatest` and `NewQuery`
// When looking for the latest update, it starts at the next period after the current time.
// upon failure tries the corresponding keys of each previous period until one is found
// (or startTime is reached, in which case there are no updates).
func ( h * Handler ) Lookup ( ctx context . Context , query * Query ) ( * cacheEntry , error ) { func ( h * Handler ) Lookup ( ctx context . Context , query * Query ) ( * cacheEntry , error ) {
timeLimit := query . TimeLimit timeLimit := query . TimeLimit
@ -213,17 +210,17 @@ func (h *Handler) Lookup(ctx context.Context, query *Query) (*cacheEntry, error)
return nil , err return nil , err
} }
log . Info ( fmt . Sprintf ( "Resource lookup finished in %d lookups" , readCount ) ) log . Info ( fmt . Sprintf ( "Feed lookup finished in %d lookups" , readCount ) )
request , _ := requestPtr . ( * Request ) request , _ := requestPtr . ( * Request )
if request == nil { if request == nil {
return nil , NewError ( ErrNotFound , "no updates found" ) return nil , NewError ( ErrNotFound , "no feed updates found" )
} }
return h . updateCache ( request ) return h . updateCache ( request )
} }
// update mutable resource cache map with specified content
// update feed updates cache with specified content
func ( h * Handler ) updateCache ( request * Request ) ( * cacheEntry , error ) { func ( h * Handler ) updateCache ( request * Request ) ( * cacheEntry , error ) {
updateAddr := request . Addr ( ) updateAddr := request . Addr ( )
@ -242,10 +239,10 @@ func (h *Handler) updateCache(request *Request) (*cacheEntry, error) {
return feedUpdate , nil return feedUpdate , nil
} }
// Update adds an actual data update
// Update publishes a feed update
// Uses the Mutable Resource metadata currently loaded in the resources map entry .
// Note that a Feed update cannot span chunks, and thus has a MAX NET LENGTH 4096, INCLUDING update header data and signature .
// It is the caller's responsibility to make sure that this data is not stale.
// This results in a max payload of `maxUpdateDataLength` (check update.go for more details)
// Note that a Mutable Resource update cannot span chunks, and thus has a MAX NET LENGTH 4096, INCLUDING update header data and signature. An error will be returned if the total length of the chunk payload will exceed this limit.
// An error will be returned if the total length of the chunk payload will exceed this limit.
// Update can only check if the caller is trying to overwrite the very last known version, otherwise it just puts the update
// Update can only check if the caller is trying to overwrite the very last known version, otherwise it just puts the update
// on the network.
// on the network.
func ( h * Handler ) Update ( ctx context . Context , r * Request ) ( updateAddr storage . Address , err error ) { func ( h * Handler ) Update ( ctx context . Context , r * Request ) ( updateAddr storage . Address , err error ) {
@ -280,18 +277,18 @@ func (h *Handler) Update(ctx context.Context, r *Request) (updateAddr storage.Ad
return r . idAddr , nil return r . idAddr , nil
} }
// Retrieves the resourc e cache value for the given nameHash
// Retrieves the feed updat e cache value for the given nameHash
func ( h * Handler ) get ( view * Feed ) * cacheEntry { func ( h * Handler ) get ( feed * Feed ) * cacheEntry {
mapKey := view . mapKey ( ) mapKey := feed . mapKey ( )
h . cacheLock . RLock ( ) h . cacheLock . RLock ( )
defer h . cacheLock . RUnlock ( ) defer h . cacheLock . RUnlock ( )
feedUpdate := h . cache [ mapKey ] feedUpdate := h . cache [ mapKey ]
return feedUpdate return feedUpdate
} }
// Sets the resource cache value for the given View
// Sets the feed update cache value for the given Feed
func ( h * Handler ) set ( view * Feed , feedUpdate * cacheEntry ) { func ( h * Handler ) set ( feed * Feed , feedUpdate * cacheEntry ) {
mapKey := view . mapKey ( ) mapKey := feed . mapKey ( )
h . cacheLock . Lock ( ) h . cacheLock . Lock ( )
defer h . cacheLock . Unlock ( ) defer h . cacheLock . Unlock ( )
h . cache [ mapKey ] = feedUpdate h . cache [ mapKey ] = feedUpdate
Javier Peletier
6 years ago