decoding

Documentation

Index

• func Middleware(target appdata.Listener, resolver DecoderResolver, opts MiddlewareOptions) (appdata.Listener, error)
• func Sync(listener appdata.Listener, source SyncSource, resolver DecoderResolver, ...) error
• type DecoderResolver
  • func ModuleSetDecoderResolver(moduleSet map[string]interface{}) DecoderResolver
• type MiddlewareOptions
• type SyncOptions
• type SyncSource

Functions

func Middleware

func Middleware(target appdata.Listener, resolver DecoderResolver, opts MiddlewareOptions) (appdata.Listener, error)

Middleware decodes raw data passed to the listener as kv-updates into decoded object updates. Module initialization is done lazily as modules are encountered in the kv-update stream.

func Sync

func Sync(listener appdata.Listener, source SyncSource, resolver DecoderResolver, opts SyncOptions) error

Sync synchronizes existing state from the sync source to the listener using the resolver to decode data.

Types

type DecoderResolver

type DecoderResolver interface {
	// DecodeModuleName decodes a module name from a byte slice passed as the actor in a KVPairUpdate.
	DecodeModuleName([]byte) (string, error)

	// EncodeModuleName encodes a module name into a byte slice that can be used as the actor in a KVPairUpdate.
	EncodeModuleName(string) ([]byte, error)

	// IterateAll iterates over all available module decoders.
	IterateAll(func(moduleName string, cdc schema.ModuleCodec) error) error

	// LookupDecoder looks up a specific module decoder.
	LookupDecoder(moduleName string) (decoder schema.ModuleCodec, found bool, err error)
}

DecoderResolver is an interface that allows indexers to discover and use module decoders.

func ModuleSetDecoderResolver

func ModuleSetDecoderResolver(moduleSet map[string]interface{}) DecoderResolver

ModuleSetDecoderResolver returns DecoderResolver that will discover modules implementing DecodeableModule in the provided module set.

type MiddlewareOptions

type MiddlewareOptions struct {
	ModuleFilter func(moduleName string) bool
}

type SyncOptions

type SyncOptions struct {
	ModuleFilter func(moduleName string) bool
}

SyncOptions are the options for Sync.

type SyncSource

type SyncSource interface {
	// IterateAllKVPairs iterates over all key-value pairs for a given module.
	IterateAllKVPairs(moduleName string, fn func(key, value []byte) error) error
}

SyncSource is an interface that allows indexers to start indexing modules with pre-existing state. It should generally be a wrapper around the key-value store.