feat: periodic feed using multi ingester

examples/gno.land/p/demo/gnorkle/feeds/periodic/feed.gno

@@ -0,0 +1,156 @@
+package periodic
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+
+	"gno.land/p/demo/gnorkle/feed"
+	"gno.land/p/demo/gnorkle/gnorkle"
+	"gno.land/p/demo/gnorkle/ingesters/multi"
+	"gno.land/p/demo/gnorkle/message"
+	"gno.land/p/demo/gnorkle/storage/simple"
+	"gno.land/p/demo/ufmt"
+)
+
+// Feed is a periodic feed.
+type Feed struct {
+	id                string
+	valueDataType     string
+	timeBetweenCommit uint
+	lastCommitTime    uint
+	ingester          gnorkle.Ingester
+	storage           gnorkle.Storage
+	tasks             []feed.Task
+}
+
+// NewFeed creates a new periodic feed.
+func NewFeed(
+	id string,
+	valueDataType string,
+	timeBetweenCommit uint,
+	ingester gnorkle.Ingester,
+	storage gnorkle.Storage,
+	tasks ...feed.Task,
+) *Feed {
+	return &Feed{
+		id:                id,
+		valueDataType:     valueDataType,
+		timeBetweenCommit: timeBetweenCommit,
+		ingester:          ingester,
+		storage:           storage,
+		tasks:             tasks,
+	}
+}
+
+// NewMultiValueFeed is a convenience function  for creating a periodic feed
+// that commits values every x times.
+func NewMultiValueFeed(
+	id string,
+	valueDataType string,
+	timeBetweenCommit uint,
+	tasks ...feed.Task,
+) *Feed {
+	return NewFeed(
+		id,
+		valueDataType,
+		timeBetweenCommit,
+		&multi.ValueIngester{},
+		simple.NewStorage(1),
+		tasks...,
+	)
+}
+
+// ID returns the feed's ID.
+func (f Feed) ID() string {
+	return f.id
+}
+
+// Type returns the feed's type.
+func (f Feed) Type() feed.Type {
+	return feed.TypePeriodic
+}
+
+// Ingest ingests a message into the feed. It either adds the value to the ingester's
+// pending values or commits the value to the storage.
+func (f *Feed) Ingest(funcType message.FuncType, msg, providerAddress string) error {
+	if f == nil {
+		return feed.ErrUndefined
+	}
+
+	switch funcType {
+	case message.FuncTypeIngest:
+		_, err := f.ingester.Ingest(msg, providerAddress)
+		if err != nil {
+			return err
+		}
+
+	case message.FuncTypeCommit:
+		// Commits the value to the storage only after x times has passed since last commit.
+		if f.lastCommitTime+f.timeBetweenCommit > f.storage.GetTime() {
+			return errors.New("time between commit not reached")
+		}
+
+		if err := f.ingester.CommitValue(f.storage, providerAddress); err != nil {
+			return err
+		}
+
+		f.lastCommitTime = f.storage.GetTime()
+
+	default:
+		return errors.New("invalid message function " + string(funcType))
+	}
+
+	return nil
+}
+
+// Value returns the feed's latest value, it's data type, and whether or not it can
+// be safely consumed. In this case it can be consumed because it's a periodic feed.
+func (f Feed) Value() (feed.Value, string, bool) {
+	return f.storage.GetLatest(), f.valueDataType, false
+}
+
+// MarshalJSON marshals the components of the feed that are needed for
+// an agent to execute tasks and send values for ingestion.
+func (f Feed) MarshalJSON() ([]byte, error) {
+	buf := new(bytes.Buffer)
+	w := bufio.NewWriter(buf)
+
+	w.Write([]byte(
+		`{"id":"` + f.id +
+			`","type":"` + ufmt.Sprintf("%d", int(f.Type())) +
+			`","value_type":"` + f.valueDataType +
+			`","tasks":[`),
+	)
+
+	first := true
+	for _, task := range f.tasks {
+		if !first {
+			w.WriteString(",")
+		}
+
+		taskJSON, err := task.MarshalJSON()
+		if err != nil {
+			return nil, err
+		}
+
+		w.Write(taskJSON)
+		first = false
+	}
+
+	w.Write([]byte("]}"))
+	w.Flush()
+
+	return buf.Bytes(), nil
+}
+
+// Tasks returns the feed's tasks. This allows task consumers to extract task
+// contents without having to marshal the entire feed.
+func (f Feed) Tasks() []feed.Task {
+	return f.tasks
+}
+
+// IsActive returns true if the feed is accepting ingestion requests from agents.
+func (f Feed) IsActive() bool {
+	return true
+}

examples/gno.land/p/demo/gnorkle/feeds/periodic/gno.mod

@@ -0,0 +1,13 @@
+module gno.land/p/demo/gnorkle/feeds/periodic
+
+require (
+	gno.land/p/demo/gnorkle/feed v0.0.0-latest
+	gno.land/p/demo/gnorkle/gnorkle v0.0.0-latest
+	gno.land/p/demo/gnorkle/ingester v0.0.0-latest
+	gno.land/p/demo/gnorkle/ingesters/multi v0.0.0-latest
+	gno.land/p/demo/gnorkle/message v0.0.0-latest
+	gno.land/p/demo/gnorkle/storage/simple v0.0.0-latest
+	gno.land/p/demo/uassert v0.0.0-latest
+	gno.land/p/demo/ufmt v0.0.0-latest
+	gno.land/p/demo/urequire v0.0.0-latest
+)