Add compressed writes to cas.go.

This follows the current tentative API being worked on in
bazelbuild/remote-apis#168. While there's technically room for it to
change, it has reached a somewhat stable point worth implementing.

go/pkg/chunker/chunker.go

@@ -22,9 +22,11 @@ var IOBufferSize = 10 * 1024 * 1024
 // ErrEOF is returned when Next is called when HasNext is false.
 var ErrEOF = errors.New("ErrEOF")
 
-// Compressor for full blobs. It is *only* thread-safe for EncodeAll calls and
-// should not be used for streamed compression.
-var fullCompressor, _ = zstd.NewWriter(nil)
+// Compressor for full blobs
+// It is *only* thread-safe for EncodeAll calls and should not be used for streamed compression.
+// While we avoid sending 0 len blobs, we do want to create zero len compressed blobs if
+// necessary.
+var fullCompressor, _ = zstd.NewWriter(nil, zstd.WithZeroFrames(true))
 
 type UploadEntry struct {
 	digest   digest.Digest
@@ -81,9 +83,6 @@ type Chunker struct {
 }
 
 func New(ue *UploadEntry, compressed bool, chunkSize int) (*Chunker, error) {
-	if compressed {
-		return nil, errors.New("compression is not supported yet")
-	}
 	if chunkSize < 1 {
 		chunkSize = DefaultChunkSize
 	}

go/pkg/client/cas.go

@@ -27,6 +27,9 @@ import (
 	log "github.com/golang/glog"
 )
 
+// DefaultCompressedBytestreamThreshold is the default threshold for transferring blobs compressed on ByteStream.Write RPCs.
+const DefaultCompressedBytestreamThreshold = 1024
+
 const logInterval = 25
 
 type requestMetadata struct {
@@ -858,6 +861,13 @@ func (c *Client) ResourceNameWrite(hash string, sizeBytes int64) string {
 	return fmt.Sprintf("%s/uploads/%s/blobs/%s/%d", c.InstanceName, uuid.New(), hash, sizeBytes)
 }
 
+// ResourceNameCompressedWrite generates a valid write resource name.
+// TODO(rubensf): Converge compressor to proto in https://github.com/bazelbuild/remote-apis/pull/168 once
+// that gets merged in.
+func (c *Client) ResourceNameCompressedWrite(hash string, sizeBytes int64) string {
+	return fmt.Sprintf("%s/uploads/%s/compressed-blobs/zstd/%s/%d", c.InstanceName, uuid.New(), hash, sizeBytes)
+}
+
 // GetDirectoryTree returns the entire directory tree rooted at the given digest (which must target
 // a Directory stored in the CAS).
 func (c *Client) GetDirectoryTree(ctx context.Context, d *repb.Digest) (result []*repb.Directory, err error) {
@@ -1377,3 +1387,14 @@ func (c *Client) DownloadFiles(ctx context.Context, execRoot string, outputs map
 	}
 	return nil
 }
+
+func (c *Client) shouldCompress(sizeBytes int64) bool {
+	return int64(c.CompressedBytestreamThreshold) >= 0 && int64(c.CompressedBytestreamThreshold) <= sizeBytes
+}
+
+func (c *Client) writeRscName(dg digest.Digest) string {
+	if c.shouldCompress(dg.Size) {
+		return c.ResourceNameCompressedWrite(dg.Hash, dg.Size)
+	}
+	return c.ResourceNameWrite(dg.Hash, dg.Size)
+}

go/pkg/client/cas_test.go

@@ -286,23 +286,26 @@ func TestWrite(t *testing.T) {
 		},
 	}
 
-	for _, tc := range tests {
-		t.Run(tc.name, func(t *testing.T) {
-			gotDg, err := c.WriteBlob(ctx, tc.blob)
-			if err != nil {
-				t.Errorf("c.WriteBlob(ctx, blob) gave error %s, wanted nil", err)
-			}
-			if fake.Err != nil {
-				t.Errorf("c.WriteBlob(ctx, blob) caused the server to return error %s (possibly unseen by c)", fake.Err)
-			}
-			if !bytes.Equal(tc.blob, fake.Buf) {
-				t.Errorf("c.WriteBlob(ctx, blob) had diff on blobs, want %v, got %v:", tc.blob, fake.Buf)
-			}
-			dg := digest.NewFromBlob(tc.blob)
-			if dg != gotDg {
-				t.Errorf("c.WriteBlob(ctx, blob) had diff on digest returned (want %s, got %s)", dg, gotDg)
-			}
-		})
+	for _, cmp := range []client.CompressedBytestreamThreshold{-1, 0} {
+		for _, tc := range tests {
+			t.Run(fmt.Sprintf("%s - CompressionThresh:%d", tc.name, cmp), func(t *testing.T) {
+				cmp.Apply(c)
+				gotDg, err := c.WriteBlob(ctx, tc.blob)
+				if err != nil {
+					t.Errorf("c.WriteBlob(ctx, blob) gave error %s, wanted nil", err)
+				}
+				if fake.Err != nil {
+					t.Errorf("c.WriteBlob(ctx, blob) caused the server to return error %s (possibly unseen by c)", fake.Err)
+				}
+				if !bytes.Equal(tc.blob, fake.Buf) {
+					t.Errorf("c.WriteBlob(ctx, blob) had diff on blobs, want %v, got %v:", tc.blob, fake.Buf)
+				}
+				dg := digest.NewFromBlob(tc.blob)
+				if dg != gotDg {
+					t.Errorf("c.WriteBlob(ctx, blob) had diff on digest returned (want %s, got %s)", dg, gotDg)
+				}
+			})
+		}
 	}
 }
 
@@ -711,74 +714,71 @@ func TestUpload(t *testing.T) {
 
 	for _, ub := range []client.UseBatchOps{false, true} {
 		for _, uo := range []client.UnifiedCASOps{false, true} {
-			t.Run(fmt.Sprintf("UsingBatch:%t,UnifiedCASOps:%t", ub, uo), func(t *testing.T) {
-				for _, tc := range tests {
-					t.Run(tc.name, func(t *testing.T) {
-						ctx := context.Background()
-						e, cleanup := fakes.NewTestEnv(t)
-						defer cleanup()
-						fake := e.Server.CAS
-						c := e.Client.GrpcClient
-						client.CASConcurrency(defaultCASConcurrency).Apply(c)
-						ub.Apply(c)
-						uo.Apply(c)
-						if tc.concurrency > 0 {
-							tc.concurrency.Apply(c)
-						}
-
-						present := make(map[digest.Digest]bool)
-						for _, blob := range tc.present {
-							fake.Put(blob)
-							present[digest.NewFromBlob(blob)] = true
-						}
-						var input []*chunker.UploadEntry
-						for _, blob := range tc.input {
-							input = append(input, chunker.EntryFromBlob(blob))
-						}
+			for _, cmp := range []client.CompressedBytestreamThreshold{-1, 0} {
+				t.Run(fmt.Sprintf("UsingBatch:%t,UnifiedCASOps:%t,CompressionThresh:%d", ub, uo, cmp), func(t *testing.T) {
+					for _, tc := range tests {
+						t.Run(tc.name, func(t *testing.T) {
+							ctx := context.Background()
+							e, cleanup := fakes.NewTestEnv(t)
+							defer cleanup()
+							fake := e.Server.CAS
+							c := e.Client.GrpcClient
+							client.CASConcurrency(defaultCASConcurrency).Apply(c)
+							cmp.Apply(c)
+							ub.Apply(c)
+							uo.Apply(c)
+							if tc.concurrency > 0 {
+								tc.concurrency.Apply(c)
+							}
 
-						missing, err := c.UploadIfMissing(ctx, input...)
-						if err != nil {
-							t.Errorf("c.UploadIfMissing(ctx, input) gave error %v, expected nil", err)
-						}
+							present := make(map[digest.Digest]bool)
+							for _, blob := range tc.present {
+								fake.Put(blob)
+								present[digest.NewFromBlob(blob)] = true
+							}
+							var input []*chunker.UploadEntry
+							for _, blob := range tc.input {
+								input = append(input, chunker.EntryFromBlob(blob))
+							}
 
-						missingSet := make(map[digest.Digest]struct{})
-						for _, dg := range missing {
-							missingSet[dg] = struct{}{}
-						}
-						for _, ue := range input {
-							dg := ue.Digest()
-							ch, err := chunker.New(ue, false, int(c.ChunkMaxSize))
+							missing, err := c.UploadIfMissing(ctx, input...)
 							if err != nil {
-								t.Fatalf("chunker.New(ue): failed to create chunker from UploadEntry: %v", err)
+								t.Errorf("c.UploadIfMissing(ctx, input) gave error %v, expected nil", err)
 							}
-							blob, err := ch.FullData()
-							if err != nil {
-								t.Errorf("ch.FullData() returned an error: %v", err)
+
+							missingSet := make(map[digest.Digest]struct{})
+							for _, dg := range missing {
+								missingSet[dg] = struct{}{}
 							}
-							if present[dg] {
-								if fake.BlobWrites(dg) > 0 {
-									t.Errorf("blob %v with digest %s was uploaded even though it was already present in the CAS", blob, dg)
+
+							for i, ue := range input {
+								dg := ue.Digest()
+								blob := tc.input[i]
+								if present[dg] {
+									if fake.BlobWrites(dg) > 0 {
+										t.Errorf("blob %v with digest %s was uploaded even though it was already present in the CAS", blob, dg)
+									}
+									if _, ok := missingSet[dg]; ok {
+										t.Errorf("Stats said that blob %v with digest %s was missing in the CAS", blob, dg)
+									}
+									continue
 								}
-								if _, ok := missingSet[dg]; ok {
-									t.Errorf("Stats said that blob %v with digest %s was missing in the CAS", blob, dg)
+								if gotBlob, ok := fake.Get(dg); !ok {
+									t.Errorf("blob %v with digest %s was not uploaded, expected it to be present in the CAS", blob, dg)
+								} else if !bytes.Equal(blob, gotBlob) {
+									t.Errorf("blob digest %s had diff on uploaded blob: want %v, got %v", dg, blob, gotBlob)
+								}
+								if _, ok := missingSet[dg]; !ok {
+									t.Errorf("Stats said that blob %v with digest %s was present in the CAS", blob, dg)
 								}
-								continue
-							}
-							if gotBlob, ok := fake.Get(dg); !ok {
-								t.Errorf("blob %v with digest %s was not uploaded, expected it to be present in the CAS", blob, dg)
-							} else if !bytes.Equal(blob, gotBlob) {
-								t.Errorf("blob digest %s had diff on uploaded blob: want %v, got %v", dg, blob, gotBlob)
 							}
-							if _, ok := missingSet[dg]; !ok {
-								t.Errorf("Stats said that blob %v with digest %s was present in the CAS", blob, dg)
+							if fake.MaxConcurrency() > defaultCASConcurrency {
+								t.Errorf("CAS concurrency %v was higher than max %v", fake.MaxConcurrency(), defaultCASConcurrency)
 							}
-						}
-						if fake.MaxConcurrency() > defaultCASConcurrency {
-							t.Errorf("CAS concurrency %v was higher than max %v", fake.MaxConcurrency(), defaultCASConcurrency)
-						}
-					})
-				}
-			})
+						})
+					}
+				})
+			}
 		}
 	}
 }

go/pkg/client/client.go

@@ -72,6 +72,11 @@ type Client struct {
 	StartupCapabilities StartupCapabilities
 	// ChunkMaxSize is maximum chunk size to use for CAS uploads/downloads.
 	ChunkMaxSize ChunkMaxSize
+	// CompressedBytestreamThreshold is the threshold in bytes for which blobs are read and written
+	// compressed. Use 0 for all writes being compressed, and a negative number for all writes being
+	// uncompressed. TODO(rubensf): Make sure this will throw an error if the server doesn't support compression,
+	// pending https://github.com/bazelbuild/remote-apis/pull/168 being submitted.
+	CompressedBytestreamThreshold CompressedBytestreamThreshold
 	// MaxBatchDigests is maximum amount of digests to batch in batched operations.
 	MaxBatchDigests MaxBatchDigests
 	// MaxBatchSize is maximum size in bytes of a batch request for batch operations.
@@ -143,6 +148,13 @@ func (s ChunkMaxSize) Apply(c *Client) {
 	c.ChunkMaxSize = s
 }
 
+type CompressedBytestreamThreshold int64
+
+// Apply sets the client's maximal chunk size s.
+func (s CompressedBytestreamThreshold) Apply(c *Client) {
+	c.CompressedBytestreamThreshold = s
+}
+
 // UtilizeLocality is to specify whether client downloads files utilizing disk access locality.
 type UtilizeLocality bool
 
@@ -454,28 +466,29 @@ func NewClient(ctx context.Context, instanceName string, params DialParams, opts
 		return nil, err
 	}
 	client := &Client{
-		InstanceName:        instanceName,
-		actionCache:         regrpc.NewActionCacheClient(casConn),
-		byteStream:          bsgrpc.NewByteStreamClient(casConn),
-		cas:                 regrpc.NewContentAddressableStorageClient(casConn),
-		execution:           regrpc.NewExecutionClient(conn),
-		operations:          opgrpc.NewOperationsClient(conn),
-		rpcTimeouts:         DefaultRPCTimeouts,
-		Connection:          conn,
-		CASConnection:       casConn,
-		ChunkMaxSize:        chunker.DefaultChunkSize,
-		MaxBatchDigests:     DefaultMaxBatchDigests,
-		MaxBatchSize:        DefaultMaxBatchSize,
-		DirMode:             DefaultDirMode,
-		ExecutableMode:      DefaultExecutableMode,
-		RegularMode:         DefaultRegularMode,
-		useBatchOps:         true,
-		StartupCapabilities: true,
-		casConcurrency:      DefaultCASConcurrency,
-		casUploaders:        semaphore.NewWeighted(DefaultCASConcurrency),
-		casDownloaders:      semaphore.NewWeighted(DefaultCASConcurrency),
-		casUploads:          make(map[digest.Digest]*uploadState),
-		Retrier:             RetryTransient(),
+		InstanceName:                  instanceName,
+		actionCache:                   regrpc.NewActionCacheClient(casConn),
+		byteStream:                    bsgrpc.NewByteStreamClient(casConn),
+		cas:                           regrpc.NewContentAddressableStorageClient(casConn),
+		execution:                     regrpc.NewExecutionClient(conn),
+		operations:                    opgrpc.NewOperationsClient(conn),
+		rpcTimeouts:                   DefaultRPCTimeouts,
+		Connection:                    conn,
+		CASConnection:                 casConn,
+		CompressedBytestreamThreshold: DefaultCompressedBytestreamThreshold,
+		ChunkMaxSize:                  chunker.DefaultChunkSize,
+		MaxBatchDigests:               DefaultMaxBatchDigests,
+		MaxBatchSize:                  DefaultMaxBatchSize,
+		DirMode:                       DefaultDirMode,
+		ExecutableMode:                DefaultExecutableMode,
+		RegularMode:                   DefaultRegularMode,
+		useBatchOps:                   true,
+		StartupCapabilities:           true,
+		casConcurrency:                DefaultCASConcurrency,
+		casUploaders:                  semaphore.NewWeighted(DefaultCASConcurrency),
+		casDownloaders:                semaphore.NewWeighted(DefaultCASConcurrency),
+		casUploads:                    make(map[digest.Digest]*uploadState),
+		Retrier:                       RetryTransient(),
 	}
 	for _, o := range opts {
 		o.Apply(client)

go/pkg/fakes/BUILD.bazel

@@ -21,6 +21,7 @@ go_library(
         "@com_github_golang_glog//:go_default_library",
         "@com_github_golang_protobuf//proto:go_default_library",
         "@com_github_golang_protobuf//ptypes:go_default_library_gen",
+        "@com_github_klauspost_compress//zstd:go_default_library",
         "@com_github_pborman_uuid//:go_default_library",
         "@go_googleapis//google/bytestream:bytestream_go_proto",
         "@go_googleapis//google/longrunning:longrunning_go_proto",