[CAPPL-40] Add Custom Compute Capability

- Pass through binary + config through the workflow engine

core/capabilities/compute/cache.go

@@ -0,0 +1,124 @@
+package compute
+
+import (
+	"fmt"
+	"sync"
+	"time"
+
+	"github.com/jonboulle/clockwork"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+
+	"github.com/smartcontractkit/chainlink-common/pkg/services"
+	"github.com/smartcontractkit/chainlink-common/pkg/workflows/wasm/host"
+)
+
+var (
+	moduleCacheHit = promauto.NewCounterVec(prometheus.CounterOpts{
+		Name: "compute_module_cache_hit",
+		Help: "hit vs non-hits of the module cache for custom compute",
+	}, []string{"hit"})
+	moduleCacheEviction = promauto.NewCounter(prometheus.CounterOpts{
+		Name: "compute_module_cache_eviction",
+		Help: "evictions from the module cache",
+	})
+	moduleCacheAddition = promauto.NewCounter(prometheus.CounterOpts{
+		Name: "compute_module_cache_addition",
+		Help: "additions to the module cache",
+	})
+)
+
+type moduleCache struct {
+	m  map[string]*module
+	mu sync.RWMutex
+
+	wg       sync.WaitGroup
+	stopChan services.StopChan
+
+	tickInterval time.Duration
+	timeout      time.Duration
+
+	clock    clockwork.Clock
+	onReaper chan struct{}
+}
+
+func newModuleCache(clock clockwork.Clock, tick, timeout time.Duration) *moduleCache {
+	return &moduleCache{
+		m:            map[string]*module{},
+		tickInterval: tick,
+		timeout:      timeout,
+		clock:        clock,
+		stopChan:     make(chan struct{}),
+	}
+}
+
+func (m *moduleCache) start() {
+	m.wg.Add(1)
+	go func() {
+		defer m.wg.Done()
+		m.reapLoop()
+	}()
+}
+
+func (m *moduleCache) close() {
+	close(m.stopChan)
+	m.wg.Wait()
+}
+
+func (m *moduleCache) reapLoop() {
+	ticker := m.clock.NewTicker(m.tickInterval)
+	for {
+		select {
+		case <-ticker.Chan():
+			m.evictOlderThan(m.timeout)
+			if m.onReaper != nil {
+				m.onReaper <- struct{}{}
+			}
+		case <-m.stopChan:
+			return
+		}
+	}
+}
+
+func (mr *moduleCache) add(id string, mod *module) {
+	mr.mu.Lock()
+	defer mr.mu.Unlock()
+	mod.lastFetchedAt = time.Now()
+	mr.m[id] = mod
+	moduleCacheAddition.Inc()
+}
+
+func (mr *moduleCache) get(id string) (*module, error) {
+	mr.mu.Lock()
+	defer mr.mu.Unlock()
+	gotModule, ok := mr.m[id]
+	if !ok {
+		moduleCacheHit.WithLabelValues("false").Inc()
+		return nil, fmt.Errorf("could not find module for id %s", id)
+	}
+
+	moduleCacheHit.WithLabelValues("true").Inc()
+	gotModule.lastFetchedAt = mr.clock.Now()
+	return gotModule, nil
+}
+
+func (mr *moduleCache) evictOlderThan(duration time.Duration) {
+	mr.mu.Lock()
+	defer mr.mu.Unlock()
+
+	evicted := 0
+	for id, m := range mr.m {
+		if mr.clock.Now().Sub(m.lastFetchedAt) > duration {
+			delete(mr.m, id)
+			m.module.Close()
+			evicted++
+		}
+	}
+
+	moduleCacheEviction.Add(float64(evicted))
+}
+
+type module struct {
+	module        *host.Module
+	lastFetchedAt time.Time
+}

core/capabilities/compute/cache_test.go

@@ -0,0 +1,55 @@
+package compute
+
+import (
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/jonboulle/clockwork"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/smartcontractkit/chainlink-common/pkg/workflows/wasm/host"
+	"github.com/smartcontractkit/chainlink/v2/core/internal/testutils/wasmtest"
+	"github.com/smartcontractkit/chainlink/v2/core/logger"
+)
+
+const (
+	binaryLocation = "test/simple/cmd/testmodule.wasm"
+	binaryCmd      = "core/capabilities/compute/test/simple/cmd"
+)
+
+func TestCache(t *testing.T) {
+	clock := clockwork.NewFakeClock()
+	tick := 1 * time.Second
+	timeout := 1 * time.Second
+
+	cache := newModuleCache(clock, tick, timeout)
+	cache.onReaper = make(chan struct{}, 1)
+	cache.start()
+
+	var binary []byte
+	binary = wasmtest.CreateTestBinary(binaryCmd, binaryLocation, false, t)
+	hmod, err := host.NewModule(&host.ModuleConfig{
+		Logger:         logger.TestLogger(t),
+		IsUncompressed: true,
+	}, binary)
+	require.NoError(t, err)
+
+	id := uuid.New().String()
+	mod := &module{
+		module: hmod,
+	}
+	cache.add(id, mod)
+
+	got, err := cache.get(id)
+	require.NoError(t, err)
+
+	assert.Equal(t, got, mod)
+
+	clock.Advance(15 * time.Second)
+	<-cache.onReaper
+	m, err := cache.get(id)
+	assert.ErrorContains(t, err, "could not find module", m)
+	defer cache.close()
+}

core/capabilities/compute/compute.go

@@ -0,0 +1,202 @@
+package compute
+
+import (
+	"context"
+	"crypto/sha256"
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/jonboulle/clockwork"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+
+	"github.com/smartcontractkit/chainlink-common/pkg/capabilities"
+	capabilitiespb "github.com/smartcontractkit/chainlink-common/pkg/capabilities/pb"
+	"github.com/smartcontractkit/chainlink-common/pkg/logger"
+	coretypes "github.com/smartcontractkit/chainlink-common/pkg/types/core"
+	"github.com/smartcontractkit/chainlink-common/pkg/values"
+	"github.com/smartcontractkit/chainlink-common/pkg/workflows/wasm/host"
+	wasmpb "github.com/smartcontractkit/chainlink-common/pkg/workflows/wasm/pb"
+)
+
+const (
+	CapabilityIDCompute = "custom_compute@1.0.0"
+
+	binaryKey = "binary"
+	configKey = "config"
+)
+
+var (
+	computeWASMInit = promauto.NewHistogramVec(prometheus.HistogramOpts{
+		Name: "compute_wasm_module_init",
+		Help: "how long it takes to initialize a WASM module",
+		Buckets: []float64{
+			float64(50 * time.Millisecond),
+			float64(100 * time.Millisecond),
+			float64(200 * time.Millisecond),
+			float64(500 * time.Millisecond),
+			float64(1 * time.Second),
+			float64(2 * time.Second),
+			float64(4 * time.Second),
+			float64(8 * time.Second),
+		},
+	}, []string{"workflowID", "stepRef"})
+	computeWASMExec = promauto.NewHistogramVec(prometheus.HistogramOpts{
+		Name: "compute_wasm_module_exec",
+		Help: "how long it takes to execute a request from a WASM module",
+		Buckets: []float64{
+			float64(50 * time.Millisecond),
+			float64(100 * time.Millisecond),
+			float64(200 * time.Millisecond),
+			float64(500 * time.Millisecond),
+			float64(1 * time.Second),
+			float64(2 * time.Second),
+			float64(4 * time.Second),
+			float64(8 * time.Second),
+		},
+	}, []string{"workflowID", "stepRef"})
+)
+
+var _ capabilities.ActionCapability = (*Compute)(nil)
+
+type Compute struct {
+	log      logger.Logger
+	registry coretypes.CapabilitiesRegistry
+	modules  *moduleCache
+}
+
+func (c *Compute) RegisterToWorkflow(ctx context.Context, request capabilities.RegisterToWorkflowRequest) error {
+	return nil
+}
+
+func (c *Compute) UnregisterFromWorkflow(ctx context.Context, request capabilities.UnregisterFromWorkflowRequest) error {
+	return nil
+}
+
+func generateID(binary []byte) string {
+	id := sha256.Sum256(binary)
+	return fmt.Sprintf("%x", id)
+}
+
+func (c *Compute) Execute(ctx context.Context, request capabilities.CapabilityRequest) (capabilities.CapabilityResponse, error) {
+	binary, err := c.popBytesValue(request.Config, binaryKey)
+	if err != nil {
+		return capabilities.CapabilityResponse{}, fmt.Errorf("invalid request: %w", err)
+	}
+
+	config, err := c.popBytesValue(request.Config, configKey)
+	if err != nil {
+		return capabilities.CapabilityResponse{}, fmt.Errorf("invalid request: %w", err)
+	}
+
+	id := generateID(binary)
+
+	m, err := c.modules.get(id)
+	if err != nil {
+		mod, err := c.initModule(id, binary, request.Metadata.WorkflowID, request.Metadata.ReferenceID)
+		if err != nil {
+			return capabilities.CapabilityResponse{}, err
+		}
+
+		m = mod
+	}
+
+	return c.executeWithModule(m.module, config, request)
+}
+
+func (c *Compute) initModule(id string, binary []byte, workflowID, referenceID string) (*module, error) {
+	initStart := time.Now()
+	mod, err := host.NewModule(&host.ModuleConfig{Logger: c.log}, binary)
+	if err != nil {
+		return nil, fmt.Errorf("failed to instantiate WASM module: %w", err)
+	}
+
+	mod.Start()
+
+	initDuration := time.Now().Sub(initStart)
+	computeWASMInit.WithLabelValues(workflowID, referenceID).Observe(float64(initDuration))
+
+	m := &module{module: mod}
+	c.modules.add(id, m)
+	return m, nil
+}
+
+func (c *Compute) popBytesValue(m *values.Map, key string) ([]byte, error) {
+	v, ok := m.Underlying[key]
+	if !ok {
+		return nil, fmt.Errorf("could not find %s in map", key)
+	}
+
+	vb, ok := v.(*values.Bytes)
+	if !ok {
+		return nil, fmt.Errorf("value is not bytes: %s", key)
+	}
+
+	delete(m.Underlying, key)
+	return vb.Underlying, nil
+}
+
+func (c *Compute) executeWithModule(module *host.Module, config []byte, req capabilities.CapabilityRequest) (capabilities.CapabilityResponse, error) {
+	executeStart := time.Now()
+	capReq := capabilitiespb.CapabilityRequestToProto(req)
+
+	wasmReq := &wasmpb.Request{
+		Id:     uuid.New().String(),
+		Config: config,
+		Message: &wasmpb.Request_ComputeRequest{
+			ComputeRequest: &wasmpb.ComputeRequest{
+				Request: capReq,
+			},
+		},
+	}
+	resp, err := module.Run(wasmReq)
+	if err != nil {
+		return capabilities.CapabilityResponse{}, err
+	}
+
+	cresppb := resp.GetComputeResponse().GetResponse()
+	if cresppb == nil {
+		return capabilities.CapabilityResponse{}, errors.New("got nil compute response")
+	}
+
+	cresp, err := capabilitiespb.CapabilityResponseFromProto(cresppb)
+	if err != nil {
+		return capabilities.CapabilityResponse{}, errors.New("could not convert response proto into response")
+	}
+
+	computeWASMExec.WithLabelValues(
+		req.Metadata.WorkflowID,
+		req.Metadata.ReferenceID,
+	).Observe(float64(time.Now().Sub(executeStart)))
+
+	return cresp, nil
+}
+
+func (c *Compute) Info(ctx context.Context) (capabilities.CapabilityInfo, error) {
+	return capabilities.NewCapabilityInfo(
+		CapabilityIDCompute,
+		capabilities.CapabilityTypeAction,
+		"WASM custom compute capability",
+	)
+}
+
+func (c *Compute) Start(ctx context.Context) error {
+	c.modules.start()
+	return c.registry.Add(ctx, c)
+}
+
+func (c *Compute) Close() error {
+	c.modules.close()
+	return nil
+}
+
+func NewAction(log logger.Logger, registry coretypes.CapabilitiesRegistry) *Compute {
+	compute := &Compute{
+		log:      log,
+		registry: registry,
+		modules:  newModuleCache(clockwork.NewRealClock(), 1*time.Minute, 10*time.Minute),
+	}
+	return compute
+}