src/plasma/plasma.fbs

// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

include "common.fbs";

// Plasma protocol specification
namespace plasma.flatbuf;

enum MessageType:long {
  // Message that gets send when a client hangs up.
  PlasmaDisconnectClient = 0,
  // Create a new object.
  PlasmaCreateRequest,
  PlasmaCreateReply,
  PlasmaCreateAndSealRequest,
  PlasmaCreateAndSealReply,
  PlasmaAbortRequest,
  PlasmaAbortReply,
  // Seal an object.
  PlasmaSealRequest,
  PlasmaSealReply,
  // Get an object that is stored on the local Plasma store.
  PlasmaGetRequest,
  PlasmaGetReply,
  // Release an object.
  PlasmaReleaseRequest,
  PlasmaReleaseReply,
  // Delete an object.
  PlasmaDeleteRequest,
  PlasmaDeleteReply,
  // See if the store contains an object (will be deprecated).
  PlasmaContainsRequest,
  PlasmaContainsReply,
  // List all objects in the store.
  PlasmaListRequest,
  PlasmaListReply,
  // Get information for a newly connecting client.
  PlasmaConnectRequest,
  PlasmaConnectReply,
  // Make room for new objects in the plasma store.
  PlasmaEvictRequest,
  PlasmaEvictReply,
  // Subscribe to a list of objects or to all objects.
  PlasmaSubscribeRequest,
  // Unsubscribe.
  PlasmaUnsubscribeRequest,
  // Sending and receiving data.
  // PlasmaDataRequest initiates sending the data, there will be one
  // such message per data transfer.
  PlasmaDataRequest,
  // PlasmaDataReply contains the actual data and is sent back to the
  // object store that requested the data. For each transfer, multiple
  // reply messages get sent. Each one contains a fixed number of bytes.
  PlasmaDataReply,
  // Object notifications.
  PlasmaNotification,
  // Set memory quota for a client.
  PlasmaSetOptionsRequest,
  PlasmaSetOptionsReply,
  // Get debugging information from the store.
  PlasmaGetDebugStringRequest,
  PlasmaGetDebugStringReply,
  // Create and seal a batch of objects. This should be used to save
  // IPC for creating many small objects.
  PlasmaCreateAndSealBatchRequest,
  PlasmaCreateAndSealBatchReply,
  // Touch a number of objects to bump their position in the LRU cache.
  PlasmaRefreshLRURequest,
  PlasmaRefreshLRUReply,
}

enum PlasmaError:int {
  // Operation was successful.
  OK,
  // Trying to create an object that already exists.
  ObjectExists,
  // Trying to access an object that doesn't exist.
  ObjectNotFound,
  // Trying to create an object but there isn't enough space in the store.
  OutOfMemory,
  // Trying to delete an object but it's not sealed.
  ObjectNotSealed,
  // Trying to delete an object but it's in use.
  ObjectInUse,
}

// Plasma store messages

struct PlasmaObjectSpec {
  // Index of the memory segment (= memory mapped file) that
  // this object is allocated in.
  segment_index: int;
  // The offset in bytes in the memory mapped file of the data.
  data_offset: ulong;
  // The size in bytes of the data.
  data_size: ulong;
  // The offset in bytes in the memory mapped file of the metadata.
  metadata_offset: ulong;
  // The size in bytes of the metadata.
  metadata_size: ulong;
  // Device to create buffer on.
  device_num: int;
}

table PlasmaSetOptionsRequest {
  // The name of the client.
  client_name: string;
  // The size of the output memory limit in bytes.
  output_memory_quota: long;
}

table PlasmaSetOptionsReply {
  // Whether setting options succeeded.
  error: PlasmaError;
}

table PlasmaGetDebugStringRequest {
}

table PlasmaGetDebugStringReply {
  // The debug string from the server.
  debug_string: string;
}

table PlasmaCreateRequest {
  // ID of the object to be created.
  object_id: string;
  // Whether to evict other objects to make room for this one.
  evict_if_full: bool;
  // The size of the object's data in bytes.
  data_size: ulong;
  // The size of the object's metadata in bytes.
  metadata_size: ulong;
  // Device to create buffer on.
  device_num: int;
}

table CudaHandle {
  handle: [ubyte];
}

table PlasmaCreateReply {
  // ID of the object that was created.
  object_id: string;
  // The object that is returned with this reply.
  plasma_object: PlasmaObjectSpec;
  // Error that occurred for this call.
  error: PlasmaError;
  // The file descriptor in the store that corresponds to the file descriptor
  // being sent to the client right after this message.
  store_fd: int;
  // The size in bytes of the segment for the store file descriptor (needed to
  // call mmap).
  mmap_size: long;
  // CUDA IPC Handle for objects on GPU.
  ipc_handle: CudaHandle;
}

table PlasmaCreateAndSealRequest {
  // ID of the object to be created.
  object_id: string;
  // Whether to evict other objects to make room for this one.
  evict_if_full: bool;
  // The object's data.
  data: string;
  // The object's metadata.
  metadata: string;
  // Hash of the object data.
  digest: string;
}

table PlasmaCreateAndSealReply {
  // Error that occurred for this call.
  error: PlasmaError;
}

table PlasmaCreateAndSealBatchRequest {
    object_ids: [string];
    // Whether to evict other objects to make room for these objects.
    evict_if_full: bool;
    data: [string];
    metadata: [string];
    digest: [string];
}

table PlasmaCreateAndSealBatchReply {
  // Error that occurred for this call.
  error: PlasmaError;
}

table PlasmaAbortRequest {
  // ID of the object to be aborted.
  object_id: string;
}

table PlasmaAbortReply {
  // ID of the object that was aborted.
  object_id: string;
}

table PlasmaSealRequest {
  // ID of the object to be sealed.
  object_id: string;
  // Hash of the object data.
  digest: string;
}

table PlasmaSealReply {
  // ID of the object that was sealed.
  object_id: string;
  // Error code.
  error: PlasmaError;
}

table PlasmaGetRequest {
  // IDs of the objects stored at local Plasma store we are getting.
  object_ids: [string];
  // The number of milliseconds before the request should timeout.
  timeout_ms: long;
}

table PlasmaGetReply {
  // IDs of the objects being returned.
  // This number can be smaller than the number of requested
  // objects if not all requested objects are stored and sealed
  // in the local Plasma store.
  object_ids: [string];
  // Plasma object information, in the same order as their IDs. The number of
  // elements in both object_ids and plasma_objects arrays must agree.
  plasma_objects: [PlasmaObjectSpec];
  // A list of the file descriptors in the store that correspond to the file
  // descriptors being sent to the client. The length of this list is the number
  // of file descriptors that the store will send to the client after this
  // message.
  store_fds: [int];
  // Size in bytes of the segment for each store file descriptor (needed to call
  // mmap). This list must have the same length as store_fds.
  mmap_sizes: [long];
  // The number of elements in both object_ids and plasma_objects arrays must agree.
  handles: [CudaHandle];
}

table PlasmaReleaseRequest {
  // ID of the object to be released.
  object_id: string;
}

table PlasmaReleaseReply {
  // ID of the object that was released.
  object_id: string;
  // Error code.
  error: PlasmaError;
}

table PlasmaDeleteRequest {
  // The number of objects to delete.
  count: int;
  // ID of the object to be deleted.
  object_ids: [string];
}

table PlasmaDeleteReply {
  // The number of objects to delete.
  count: int;
  // ID of the object that was deleted.
  object_ids: [string];
  // Error code.
  errors: [PlasmaError];
}

table PlasmaContainsRequest {
  // ID of the object we are querying.
  object_id: string;
}

table PlasmaContainsReply {
  // ID of the object we are querying.
  object_id: string;
  // 1 if the object is in the store and 0 otherwise.
  has_object: int;
}

table PlasmaListRequest {
}

table PlasmaListReply {
  objects: [ObjectInfo];
}

// PlasmaConnect is used by a plasma client the first time it connects with the
// store. This is not really necessary, but is used to get some information
// about the store such as its memory capacity.

table PlasmaConnectRequest {
}

table PlasmaConnectReply {
  // The memory capacity of the store.
  memory_capacity: long;
}

table PlasmaEvictRequest {
  // Number of bytes that shall be freed.
  num_bytes: ulong;
}

table PlasmaEvictReply {
  // Number of bytes that have been freed.
  num_bytes: ulong;
}

table PlasmaSubscribeRequest {
}

table PlasmaNotification {
  object_info: [ObjectInfo];
}

table PlasmaDataRequest {
  // ID of the object that is requested.
  object_id: string;
  // The host address where the data shall be sent to.
  address: string;
  // The port of the manager the data shall be sent to.
  port: int;
}

table PlasmaDataReply {
  // ID of the object that will be sent.
  object_id: string;
  // Size of the object data in bytes.
  object_size: ulong;
  // Size of the metadata in bytes.
  metadata_size: ulong;
}

table PlasmaRefreshLRURequest {
  // ID of the objects to be bumped in the LRU cache.
  object_ids: [string];
}

table PlasmaRefreshLRUReply {
}