ray/src/plasma/plasma.h

#ifndef PLASMA_H
#define PLASMA_H

#include <inttypes.h>
#include <stdio.h>
#include <errno.h>
#include <stddef.h>
#include <string.h>

#include "common.h"

#include "utarray.h"
#include "uthash.h"

typedef struct {
  int64_t data_size;
  int64_t metadata_size;
  int64_t create_time;
  int64_t construct_duration;
} plasma_object_info;

/* Handle to access memory mapped file and map it into client address space */
typedef struct {
  /** The file descriptor of the memory mapped file in the store. It is used
   * as a unique identifier of the file in the client to look up the
   * corresponding file descriptor on the client's side. */
  int store_fd;
  /** The size in bytes of the memory mapped file. */
  int64_t mmap_size;
} object_handle;

typedef struct {
  /** Handle for memory mapped file the object is stored in. */
  object_handle handle;
  /** The offset in bytes in the memory mapped file of the data. */
  ptrdiff_t data_offset;
  /** The offset in bytes in the memory mapped file of the metadata. */
  ptrdiff_t metadata_offset;
  /** The size in bytes of the data. */
  int64_t data_size;
  /** The size in bytes of the metadata. */
  int64_t metadata_size;
} plasma_object;

enum object_status { OBJECT_NOT_FOUND = 0, OBJECT_FOUND = 1 };

typedef enum { OPEN, SEALED } object_state;

enum plasma_message_type {
  /** Create a new object. */
  PLASMA_CREATE = 128,
  /** Get an object. */
  PLASMA_GET,
  /** Tell the store that the client no longer needs an object. */
  PLASMA_RELEASE,
  /** Check if an object is present. */
  PLASMA_CONTAINS,
  /** Seal an object. */
  PLASMA_SEAL,
  /** Delete an object. */
  PLASMA_DELETE,
  /** Evict objects from the store. */
  PLASMA_EVICT,
  /** Subscribe to notifications about sealed objects. */
  PLASMA_SUBSCRIBE,
  /** Request transfer to another store. */
  PLASMA_TRANSFER,
  /** Header for sending data. */
  PLASMA_DATA,
  /** Request a fetch of an object in another store. */
  PLASMA_FETCH,
  /** Wait until an object becomes available. */
  PLASMA_WAIT
};

typedef struct {
  /** The size of the object's data. */
  int64_t data_size;
  /** The size of the object's metadata. */
  int64_t metadata_size;
  /** The timeout of the request. */
  uint64_t timeout;
  /** The number of objects we wait for for wait. */
  int num_returns;
  /** In a transfer request, this is the IP address of the Plasma Manager to
   *  transfer the object to. */
  uint8_t addr[4];
  /** In a transfer request, this is the port of the Plasma Manager to transfer
   *  the object to. */
  int port;
  /** A number of bytes. This is used for eviction requests. */
  int64_t num_bytes;
  /** The number of object IDs that will be included in this request. */
  int num_object_ids;
  /** The IDs of the objects that the request is about. */
  object_id object_ids[1];
} plasma_request;

typedef struct {
  /** The object that is returned with this reply. */
  plasma_object object;
  /** This is used only to respond to requests of type
   *  PLASMA_CONTAINS or PLASMA_FETCH. It is 1 if the object is
   *  present and 0 otherwise. Used for plasma_contains and
   *  plasma_fetch. */
  int has_object;
  /** A number of bytes. This is used for replies to eviction requests. */
  int64_t num_bytes;
  /** Number of object IDs a wait is returning. */
  int num_objects_returned;
  /** The number of object IDs that will be included in this reply. */
  int num_object_ids;
  /** The IDs of the objects that this reply refers to. */
  object_id object_ids[1];
} plasma_reply;

/** This type is used by the Plasma store. It is here because it is exposed to
 *  the eviction policy. */
typedef struct {
  /** Object id of this object. */
  object_id object_id;
  /** Object info like size, creation time and owner. */
  plasma_object_info info;
  /** Memory mapped file containing the object. */
  int fd;
  /** Size of the underlying map. */
  int64_t map_size;
  /** Offset from the base of the mmap. */
  ptrdiff_t offset;
  /** Handle for the uthash table. */
  UT_hash_handle handle;
  /** Pointer to the object data. Needed to free the object. */
  uint8_t *pointer;
  /** An array of the clients that are currently using this object. */
  UT_array *clients;
  /** The state of the object, e.g., whether it is open or sealed. */
  object_state state;
} object_table_entry;

/** The plasma store information that is exposed to the eviction policy. */
typedef struct {
  /** Objects that are in the Plasma store. */
  object_table_entry *objects;
} plasma_store_info;

#endif