solver: implement IgnoreCache LLB Metadata

Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>

cmd/buildctl/build.go

@@ -55,7 +55,7 @@ var buildCommand = cli.Command{
 		},
 		cli.BoolFlag{
 			Name:  "no-cache",
-			Usage: "Disable cache for all the vertices. (Not yet implemented.) Frontend is not supported.",
+			Usage: "Disable cache for all the vertices. Frontend is not supported.",
 		},
 		cli.StringFlag{
 			Name:  "export-cache",

solver/jobs.go

@@ -41,6 +41,63 @@ func newJobList() *jobList {
 	return jl
 }
 
+// jobInstructionCache implements InstructionCache.
+// jobInstructionCache is instantiated for each of job instances rather than jobList or solver instances.
+// Lookup for objects with IgnoreCache fail until Set is called.
+type jobInstructionCache struct {
+	mu sync.RWMutex
+	InstructionCache
+	ignoreCache  map[digest.Digest]struct{}
+	setInThisJob map[digest.Digest]struct{}
+}
+
+// Probe implements InstructionCache
+func (jic *jobInstructionCache) Probe(ctx context.Context, key digest.Digest) (bool, error) {
+	jic.mu.RLock()
+	defer jic.mu.RUnlock()
+	_, ignoreCache := jic.ignoreCache[key]
+	_, setInThisJob := jic.setInThisJob[key]
+	if ignoreCache && !setInThisJob {
+		return false, nil
+	}
+	return jic.InstructionCache.Probe(ctx, key)
+}
+
+// Lookup implements InstructionCache
+func (jic *jobInstructionCache) Lookup(ctx context.Context, key digest.Digest, msg string) (interface{}, error) {
+	jic.mu.RLock()
+	defer jic.mu.RUnlock()
+	_, ignoreCache := jic.ignoreCache[key]
+	_, setInThisJob := jic.setInThisJob[key]
+	if ignoreCache && !setInThisJob {
+		return nil, nil
+	}
+	return jic.InstructionCache.Lookup(ctx, key, msg)
+}
+
+// Set implements InstructionCache
+func (jic *jobInstructionCache) Set(key digest.Digest, ref interface{}) error {
+	jic.mu.Lock()
+	defer jic.mu.Unlock()
+	jic.setInThisJob[key] = struct{}{}
+	return jic.InstructionCache.Set(key, ref)
+}
+
+// SetIgnoreCache is jobInstructionCache-specific extension
+func (jic *jobInstructionCache) SetIgnoreCache(key digest.Digest) {
+	jic.mu.Lock()
+	defer jic.mu.Unlock()
+	jic.ignoreCache[key] = struct{}{}
+}
+
+func newJobInstructionCache(base InstructionCache) *jobInstructionCache {
+	return &jobInstructionCache{
+		InstructionCache: base,
+		ignoreCache:      make(map[digest.Digest]struct{}),
+		setInThisJob:     make(map[digest.Digest]struct{}),
+	}
+}
+
 func (jl *jobList) new(ctx context.Context, id string, pr progress.Reader, cache InstructionCache) (context.Context, *job, error) {
 	jl.mu.Lock()
 	defer jl.mu.Unlock()
@@ -52,7 +109,8 @@ func (jl *jobList) new(ctx context.Context, id string, pr progress.Reader, cache
 	pw, _, _ := progress.FromContext(ctx) // TODO: remove this
 	sid := session.FromContext(ctx)
 
-	j := &job{l: jl, pr: progress.NewMultiReader(pr), pw: pw, session: sid, cache: cache, cached: map[string]*cacheRecord{}}
+	// TODO(AkihiroSuda): find a way to integrate map[string]*cacheRecord to jobInstructionCache?
+	j := &job{l: jl, pr: progress.NewMultiReader(pr), pw: pw, session: sid, cache: newJobInstructionCache(cache), cached: map[string]*cacheRecord{}}
 	jl.refs[id] = j
 	jl.updateCond.Broadcast()
 	go func() {
@@ -96,7 +154,7 @@ type job struct {
 	pr      *progress.MultiReader
 	pw      progress.Writer
 	session string
-	cache   InstructionCache
+	cache   *jobInstructionCache
 	cached  map[string]*cacheRecord
 }
 
@@ -114,14 +172,14 @@ func (j *job) load(def *pb.Definition, resolveOp ResolveOpFunc) (*Input, error)
 }
 
 func (j *job) loadInternal(def *pb.Definition, resolveOp ResolveOpFunc) (*Input, error) {
-	vtx, idx, err := loadLLB(def, func(dgst digest.Digest, op *pb.Op, load func(digest.Digest) (interface{}, error)) (interface{}, error) {
+	vtx, idx, err := loadLLB(def, func(dgst digest.Digest, pbOp *pb.Op, load func(digest.Digest) (interface{}, error)) (interface{}, error) {
 		if st, ok := j.l.actives[dgst]; ok {
 			if vtx, ok := st.jobs[j]; ok {
 				return vtx, nil
 			}
 		}
 		opMetadata := def.Metadata[dgst]
-		vtx, err := newVertex(dgst, op, &opMetadata, load)
+		vtx, err := newVertex(dgst, pbOp, &opMetadata, load)
 		if err != nil {
 			return nil, err
 		}
@@ -143,6 +201,15 @@ func (j *job) loadInternal(def *pb.Definition, resolveOp ResolveOpFunc) (*Input,
 			if err != nil {
 				return nil, err
 			}
+			for i, input := range pbOp.Inputs {
+				if inputMetadata := def.Metadata[input.Digest]; inputMetadata.IgnoreCache {
+					k, err := s.CacheKey(ctx, Index(i))
+					if err != nil {
+						return nil, err
+					}
+					j.cache.SetIgnoreCache(k)
+				}
+			}
 			st.solver = s
 
 			j.l.actives[dgst] = st
@@ -218,9 +285,6 @@ func (j *job) cacheExporter(ref Reference) (CacheExporter, error) {
 }
 
 func getRef(s VertexSolver, ctx context.Context, v *vertex, index Index, cache InstructionCache) (Reference, error) {
-	if v.metadata != nil && v.metadata.GetIgnoreCache() {
-		logrus.Warnf("Unimplemented vertex metadata: IgnoreCache (%s, %s)", v.digest, v.name)
-	}
 	k, err := s.CacheKey(ctx, index)
 	if err != nil {
 		return nil, err