Add go implementation

Author: rculbertson

modal-go/function.go

@@ -8,16 +8,15 @@ import (
 	"crypto/md5"
 	"crypto/sha256"
 	"encoding/base64"
+	"errors"
 	"fmt"
-	"io"
 	"net/http"
 	"time"
 
 	pickle "github.com/kisielk/og-rek"
 	pb "github.com/modal-labs/libmodal/modal-go/proto/modal_proto"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
-	"google.golang.org/protobuf/proto"
 )
 
 // From: modal/_utils/blob_utils.py
@@ -26,6 +25,9 @@ const maxObjectSizeBytes int = 2 * 1024 * 1024 // 2 MiB
 // From: modal-client/modal/_utils/function_utils.py
 const outputsTimeout time.Duration = time.Second * 55
 
+// From: client/modal/_functions.py
+const maxSystemRetries = 8
+
 func timeNowSeconds() float64 {
 	return float64(time.Now().UnixNano()) / 1e9
 }
@@ -85,7 +87,7 @@ func pickleDeserialize(buffer []byte) (any, error) {
 }
 
 // Serializes inputs, make a function call and return its ID
-func (f *Function) execFunctionCall(args []any, kwargs map[string]any, invocationType pb.FunctionCallInvocationType) (*string, error) {
+func (f *Function) createInput(args []any, kwargs map[string]any) (*pb.FunctionInput, error) {
 	payload, err := pickleSerialize(pickle.Tuple{args, kwargs})
 	if err != nil {
 		return nil, err
@@ -102,132 +104,57 @@ func (f *Function) execFunctionCall(args []any, kwargs map[string]any, invocatio
 		argsBlobId = &blobId
 	}
 
-	// Single input sync invocation
-	var functionInputs []*pb.FunctionPutInputsItem
-	functionInputItem := pb.FunctionPutInputsItem_builder{
-		Idx: 0,
-		Input: pb.FunctionInput_builder{
-			Args:       argsBytes,
-			ArgsBlobId: argsBlobId,
-			DataFormat: pb.DataFormat_DATA_FORMAT_PICKLE,
-			MethodName: f.MethodName,
-		}.Build(),
-	}.Build()
-	functionInputs = append(functionInputs, functionInputItem)
-
-	functionMapResponse, err := client.FunctionMap(f.ctx, pb.FunctionMapRequest_builder{
-		FunctionId:                 f.FunctionId,
-		FunctionCallType:           pb.FunctionCallType_FUNCTION_CALL_TYPE_UNARY,
-		FunctionCallInvocationType: invocationType,
-		PipelinedInputs:            functionInputs,
-	}.Build())
-	if err != nil {
-		return nil, fmt.Errorf("FunctionMap error: %w", err)
-	}
-
-	functionCallId := functionMapResponse.GetFunctionCallId()
-	return &functionCallId, nil
+	return pb.FunctionInput_builder{
+		Args:       argsBytes,
+		ArgsBlobId: argsBlobId,
+		DataFormat: pb.DataFormat_DATA_FORMAT_PICKLE,
+		MethodName: f.MethodName,
+	}.Build(), nil
 }
 
 // Remote executes a single input on a remote Function.
 func (f *Function) Remote(args []any, kwargs map[string]any) (any, error) {
-	invocationType := pb.FunctionCallInvocationType_FUNCTION_CALL_INVOCATION_TYPE_SYNC
-	functionCallId, err := f.execFunctionCall(args, kwargs, invocationType)
+	input, err := f.createInput(args, kwargs)
 	if err != nil {
 		return nil, err
 	}
-
-	return pollFunctionOutput(f.ctx, *functionCallId, nil)
-}
-
-// Spawn starts running a single input on a remote function.
-func (f *Function) Spawn(args []any, kwargs map[string]any) (*FunctionCall, error) {
-	invocationType := pb.FunctionCallInvocationType_FUNCTION_CALL_INVOCATION_TYPE_ASYNC
-	functionCallId, err := f.execFunctionCall(args, kwargs, invocationType)
+	invocation, err := CreateControlPlaneInvocation(f.ctx, f.FunctionId, input, pb.FunctionCallInvocationType_FUNCTION_CALL_INVOCATION_TYPE_SYNC)
 	if err != nil {
 		return nil, err
 	}
-	functionCall := FunctionCall{
-		FunctionCallId: *functionCallId,
-		ctx:            f.ctx,
-	}
-	return &functionCall, nil
-}
-
-// Poll for ouputs for a given FunctionCall ID.
-func pollFunctionOutput(ctx context.Context, functionCallId string, timeout *time.Duration) (any, error) {
-	startTime := time.Now()
-	pollTimeout := outputsTimeout
-	if timeout != nil {
-		// Refresh backend call once per outputsTimeout.
-		pollTimeout = min(*timeout, outputsTimeout)
-	}
-
+	// TODO(ryan): Add tests for retries.
+	retryCount := uint32(0)
 	for {
-		response, err := client.FunctionGetOutputs(ctx, pb.FunctionGetOutputsRequest_builder{
-			FunctionCallId: functionCallId,
-			MaxValues:      1,
-			Timeout:        float32(pollTimeout.Seconds()),
-			LastEntryId:    "0-0",
-			ClearOnSuccess: true,
-			RequestedAt:    timeNowSeconds(),
-		}.Build())
-		if err != nil {
-			return nil, fmt.Errorf("FunctionGetOutputs failed: %w", err)
-		}
-
-		// Output serialization may fail if any of the output items can't be deserialized
-		// into a supported Go type. Users are expected to serialize outputs correctly.
-		outputs := response.GetOutputs()
-		if len(outputs) > 0 {
-			return processResult(ctx, outputs[0].GetResult(), outputs[0].GetDataFormat())
+		output, err := invocation.AwaitOutput(nil)
+		if err == nil {
+			return output, nil
 		}
-
-		if timeout != nil {
-			remainingTime := *timeout - time.Since(startTime)
-			if remainingTime <= 0 {
-				message := fmt.Sprintf("Timeout exceeded: %.1fs", timeout.Seconds())
-				return nil, FunctionTimeoutError{message}
+		if errors.As(err, &InternalFailure{}) && retryCount <= maxSystemRetries {
+			if retryErr := invocation.Retry(retryCount); retryErr != nil {
+				return nil, retryErr
 			}
-			pollTimeout = min(outputsTimeout, remainingTime)
+			retryCount++
+			continue
 		}
+		return nil, err
 	}
 }
 
-// processResult processes the result from an invocation.
-func processResult(ctx context.Context, result *pb.GenericResult, dataFormat pb.DataFormat) (any, error) {
-	if result == nil {
-		return nil, RemoteError{"Received null result from invocation"}
+// Spawn starts running a single input on a remote function.
+func (f *Function) Spawn(args []any, kwargs map[string]any) (*FunctionCall, error) {
+	input, err := f.createInput(args, kwargs)
+	if err != nil {
+		return nil, err
 	}
-
-	var data []byte
-	var err error
-	switch result.WhichDataOneof() {
-	case pb.GenericResult_Data_case:
-		data = result.GetData()
-	case pb.GenericResult_DataBlobId_case:
-		data, err = blobDownload(ctx, result.GetDataBlobId())
-		if err != nil {
-			return nil, err
-		}
-	case pb.GenericResult_DataOneof_not_set_case:
-		data = nil
+	invocation, err := CreateControlPlaneInvocation(f.ctx, f.FunctionId, input, pb.FunctionCallInvocationType_FUNCTION_CALL_INVOCATION_TYPE_SYNC)
+	if err != nil {
+		return nil, err
 	}
-
-	switch result.GetStatus() {
-	case pb.GenericResult_GENERIC_STATUS_TIMEOUT:
-		return nil, FunctionTimeoutError{result.GetException()}
-	case pb.GenericResult_GENERIC_STATUS_INTERNAL_FAILURE:
-		return nil, InternalFailure{result.GetException()}
-	case pb.GenericResult_GENERIC_STATUS_SUCCESS:
-		// Proceed to the block below this switch statement.
-	default:
-		// In this case, `result.GetData()` may have a pickled user code exception with traceback
-		// from Python. We ignore this and only take the string representation.
-		return nil, RemoteError{result.GetException()}
+	functionCall := FunctionCall{
+		FunctionCallId: invocation.FunctionCallId,
+		ctx:            f.ctx,
 	}
-
-	return deserializeDataFormat(data, dataFormat)
+	return &functionCall, nil
 }
 
 // blobUpload uploads a blob to storage and returns its ID.
@@ -272,40 +199,3 @@ func blobUpload(ctx context.Context, data []byte) (string, error) {
 		return "", fmt.Errorf("missing upload URL in BlobCreate response")
 	}
 }
-
-// blobDownload downloads a blob by its ID.
-func blobDownload(ctx context.Context, blobId string) ([]byte, error) {
-	resp, err := client.BlobGet(ctx, pb.BlobGetRequest_builder{
-		BlobId: blobId,
-	}.Build())
-	if err != nil {
-		return nil, err
-	}
-	s3resp, err := http.Get(resp.GetDownloadUrl())
-	if err != nil {
-		return nil, fmt.Errorf("failed to download blob: %w", err)
-	}
-	defer s3resp.Body.Close()
-	buf, err := io.ReadAll(s3resp.Body)
-	if err != nil {
-		return nil, fmt.Errorf("failed to read blob data: %w", err)
-	}
-	return buf, nil
-}
-
-func deserializeDataFormat(data []byte, dataFormat pb.DataFormat) (any, error) {
-	switch dataFormat {
-	case pb.DataFormat_DATA_FORMAT_PICKLE:
-		return pickleDeserialize(data)
-	case pb.DataFormat_DATA_FORMAT_ASGI:
-		return nil, fmt.Errorf("ASGI data format is not supported in Go")
-	case pb.DataFormat_DATA_FORMAT_GENERATOR_DONE:
-		var done pb.GeneratorDone
-		if err := proto.Unmarshal(data, &done); err != nil {
-			return nil, fmt.Errorf("failed to unmarshal GeneratorDone: %w", err)
-		}
-		return &done, nil
-	default:
-		return nil, fmt.Errorf("unsupported data format: %s", dataFormat.String())
-	}
-}

modal-go/function_call.go

@@ -41,7 +41,8 @@ func (fc *FunctionCall) Get(options *FunctionCallGetOptions) (any, error) {
 		options = &FunctionCallGetOptions{}
 	}
 	ctx := fc.ctx
-	return pollFunctionOutput(ctx, fc.FunctionCallId, options.Timeout)
+	invocation := ControlPlaneInvocationFromFunctionCallId(ctx, fc.FunctionCallId)
+	return invocation.AwaitOutput(options.Timeout)
 }
 
 // FunctionCallCancelOptions are options for cancelling Function Calls.