Replace custom blob gRPC API with ByteStream

client/proto/isolate_bot.proto

-// Copyright 2016 The LUCI Authors. All rights reserved.
-// Use of this source code is governed under the Apache License, Version 2.0
-// that can be found in the LICENSE file.
-
-// This describes the interface a Swarming bot can use to contact an Isolate
-// server over a gRPC proxy. It essentially duplicates the portions of the
-// "native" Isolate REST API that's used by the bot.
-//
-// This proto is *not yet stable* and *will* change over time in non-backward-
-// compatible ways.
-
-syntax = "proto3";
-
-package luci.swarming.bot;
-
-// FileService exposes the main operations of an Isolate server
-// to upload and download blobs.
-service FileService {
-  // Unlike in the native Isolate API, it is not *necessary* to
-  // call Contains prior to pushing a blob, as Contains does not
-  // return "upload tickets." The BlobStatus returned by Contains
-  // will have succeeded = True if all digests were found, and
-  // false for any other reason (missing blobs, network error,
-  // etc.)
-  rpc Contains(ContainsRequest) returns (ContainsReply);
-
-  // PushBlobs can push one or more blobs at a time (serially),
-  // with each blob transmitted as one or more chunks. At the
-  // beginning of a new blob, the chunk offset should be zero
-  // and the digest must be provided. The function returns true
-  // only if all blobs are successfully received, and returns
-  // as soon as an error occurs.
-  rpc PushBlobs(stream PushBlobsRequest) returns (PushBlobsReply);
-
-  // FetchBlobs takes a list of digests and returns them all as
-  // a stream of BlobChunks.
-  rpc FetchBlobs(FetchBlobsRequest) returns (stream FetchBlobsReply);
-}
-
-message ContainsRequest {
-  repeated ContentDigest digest = 1;
-}
-
-message ContainsReply {
-  BlobStatus status = 1;
-}
-
-message PushBlobsRequest {
-  BlobChunk data = 1;
-}
-
-message PushBlobsReply {
-  BlobStatus status = 1;
-}
-
-message FetchBlobsRequest {
-  repeated ContentDigest digest = 1;
-}
-
-message FetchBlobsReply {
-  BlobStatus status = 1;
-  BlobChunk data = 2;
-}
-
-message BlobChunk {
-  // The digest is optional for all chunks except
-  // the first that represents a blob.
-  ContentDigest digest = 1;
-  int64 offset = 2;
-  bytes data = 3;
-}
-
-message ContentDigest {
-  // At present, "digest" is a 20-byte SHA1 hash.
-  bytes digest = 1;
-
-  // size_bytes is the size of the blob during uploads.
-  // During requests to FetchBlobs, the size is ignored.
-  int64 size_bytes = 2;
-
-  // Currently "0" to represents the SHA1 hash; may
-  // be incremented to allow other hash functions.
-  int32 version = 3;
-}
-
-message BlobStatus {
-  // True if the entire function succeeded.
-  bool succeeded = 1;
-
-  // "error" will be set to one of the following if succeeded is false.
-  enum ErrorCode {
-    // Typically an internal proxy error; error_detail may have more
-    // information.
-    UNKNOWN = 0;
-
-    // The client behaved incorrectly. error_detail should have more
-    // information.
-    INVALID_ARGUMENT = 1;
-
-    // Isolate is missing the nodes specified by missing_digest.
-    MISSING_DIGEST = 2;
-
-     // Upload only error, when requested digest does not match the
-     // server side computed one.
-    DIGEST_MISMATCH = 3;
-  }
-  ErrorCode error = 2;
-
-  // Human-readable error text
-  string error_detail = 3;
-
-  // If error is MISSIN_DIGEST, this will be populated with the
-  // digests that are missing.
-  repeated ContentDigest missing_digest = 4;
-}
-