# Copyright 2015 gRPC authors.
#
# Licensed 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.

# GRPC contains the General RPC module.
module GRPC
  module Core
    # StatusCodes defines the canonical error codes used by gRPC for the RPC
    # API.
    module StatusCodes
      # OK is returned on success.
      OK = 0

      # Canceled indicates the operation was canceled (typically by the caller).
      CANCELLED = 1

      # Unknown error. An example of where this error may be returned is if a
      # Status value received from another address space belongs to an
      # error-space that is not known in this address space. Also errors raised
      # by APIs that do not return enough error information may be converted to
      # this error.
      UNKNOWN = 2

      # InvalidArgument indicates client specified an invalid argument. Note
      # that this differs from FailedPrecondition. It indicates arguments that
      # are problematic regardless of the state of the system (e.g., a malformed
      # file name).
      INVALID_ARGUMENT = 3

      # DeadlineExceeded means operation expired before completion. For
      # operations that change the state of the system, this error may be
      # returned even if the operation has completed successfully. For example,
      # a successful response from a server could have been delayed long enough
      # for the deadline to expire.
      DEADLINE_EXCEEDED = 4

      # NotFound means some requested entity (e.g., file or directory) was not
      # found.
      NOT_FOUND = 5

      # AlreadyExists means an attempt to create an entity failed because one
      # already exists.
      ALREADY_EXISTS = 6

      # PermissionDenied indicates the caller does not have permission to
      # execute the specified operation. It must not be used for rejections
      # caused by exhausting some resource (use ResourceExhausted instead for
      # those errors). It must not be used if the caller cannot be identified
      # (use Unauthenticated instead for those errors).
      PERMISSION_DENIED = 7

      # ResourceExhausted indicates some resource has been exhausted, perhaps a
      # per-user quota, or perhaps the entire file system is out of space.
      RESOURCE_EXHAUSTED = 8

      # FailedPrecondition indicates operation was rejected because the system
      # is not in a state required for the operation's execution. For example,
      # directory to be deleted may be non-empty, an rmdir operation is applied
      # to a non-directory, etc.
      #
      # A litmus test that may help a service implementor in deciding between
      # FailedPrecondition, Aborted, and Unavailable:
      #  (a) Use Unavailable if the client can retry just the failing call.
      #  (b) Use Aborted if the client should retry at a higher-level (e.g.,
      #      restarting a read-modify-write sequence).
      #  (c) Use FailedPrecondition if the client should not retry until the
      #      system state has been explicitly fixed. E.g., if an "rmdir" fails
      #      because the directory is non-empty, FailedPrecondition should be
      #      returned since the client should not retry unless they have first
      #      fixed up the directory by deleting files from it.
      #  (d) Use FailedPrecondition if the client performs conditional REST
      #      Get/Update/Delete on a resource and the resource on the server does
      #      not match the condition. E.g., conflicting read-modify-write on the
      #      same resource.
      FAILED_PRECONDITION = 9

      # Aborted indicates the operation was aborted, typically due to a
      # concurrency issue like sequencer check failures, transaction aborts,
      # etc.
      #
      # See litmus test above for deciding between FailedPrecondition, Aborted,
      # and Unavailable.
      ABORTED = 10

      # OutOfRange means operation was attempted past the valid range. E.g.,
      # seeking or reading past end of file.
      #
      # Unlike InvalidArgument, this error indicates a problem that may be fixed
      # if the system state changes. For example, a 32-bit file system will
      # generate InvalidArgument if asked to read at an offset that is not in
      # the range [0,2^32-1], but it will generate OutOfRange if asked to read
      # from an offset past the current file size.
      #
      # There is a fair bit of overlap between FailedPrecondition and
      # OutOfRange. We recommend using OutOfRange (the more specific error) when
      # it applies so that callers who are iterating through a space can easily
      # look for an OutOfRange error to detect when they are done.
      OUT_OF_RANGE = 11

      # Unimplemented indicates operation is not implemented or not
      # supported/enabled in this service.
      UNIMPLEMENTED = 12

      # Internal errors. Means some invariants expected by underlying system has
      # been broken. If you see one of these errors, something is very broken.
      INTERNAL = 13

      # Unavailable indicates the service is currently unavailable. This is a
      # most likely a transient condition and may be corrected by retrying with
      # a backoff. Note that it is not always safe to retry non-idempotent
      # operations.
      #
      # See litmus test above for deciding between FailedPrecondition, Aborted,
      # and Unavailable.
      UNAVAILABLE = 14

      # DataLoss indicates unrecoverable data loss or corruption.
      DATA_LOSS = 15

      # Unauthenticated indicates the request does not have valid authentication
      # credentials for the operation.
      UNAUTHENTICATED = 16
    end
  end
end