API Docs for: 2.2.2
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FetchValue Class

Extends CommandBase
Defined in: lib/commands/kv/fetchvalue.js:13
Module: KV

Command used to fetch an object from Riak.

As a convenience, a builder class is provided:

var fetch = new FetchValue.Builder()
    .withBucket('myBucket')
    .withKey('myKey')
    .withCallback(myCallback)
    .build();

See FetchValue.Builder

Constructor

FetchValue

(
  • options
  • callback
)

Defined in lib/commands/kv/fetchvalue.js:13

Parameters:

  • options Object

    The options for this command.

    • [bucketType=default] String optional

      The bucket type in riak. If not supplied 'default' is used.

    • bucket String

      The bucket in riak.

    • key String

      The key for the object you want to fetch.

    • [convertToJs=false] Boolean optional

      Convert the values stored in riak to a JS object using JSON.parse()

    • [conflictResolver] Function optional

      A function used to resolve siblings to a single object.

      • objects RiakObject[] | Object
        The array of objects returned from Riak.
    • [timeout] Number optional

      Set a timeout for this operation.

    • [r] Number optional

      The R value to use for this fetch.

    • [pr] Number optional

      The PR value to use for this fetch.

    • [notFoundOk] Boolean optional

      If true a vnode returning notfound for a key increments the r tally.

    • [useBasicQuorum] Boolean optional

      Controls whether a read request should return early in some fail cases.

    • [returnDeletedVClock] Boolean optional

      True to return tombstones.

    • [headOnly] Boolean optional

      Return only the metadata.

    • [ifModified] Buffer optional

      Return the object if the supplied vclock does not match (the object is modified).

  • callback Function

    The callback to be executed when the operation completes.

    • err String

      An error message. Will be null if no error.

    • response Object

      the response from Riak.

      • isNotFound Boolean
        True if there was no value in Riak.
      • isUnchanged Boolean
        True if the object has not changed (based on a vclock provided via ifModified)
      • vclock Buffer
        The vector clock for this object (and its siblings)
      • values Object | RiakObject[]
        An array of one or more values. Either RiakObjects or JS objects if convertToJs was used.
    • data Object

      additional error data. Will be null if no error.

Methods

constructPbRequest

() Object protected

Inherited from CommandBase: lib/commands/commandbase.js:128

Construct and return the Riak protocol buffer message for this command. Subclasses must override this method.

Returns:

Object: a protocol buffer message builder

getCallback

() Function private

Inherited from CommandBase: lib/commands/commandbase.js:68

Fires the user's callback with the arguments passed in.

Returns:

Function: the user supplied callback

getExpectedResponseCode

() Number private

Inherited from CommandBase: lib/commands/commandbase.js:78

Returns the expected response code for this command.

Returns:

Number: the expected response code for this command.

getPbReqBuilder

() Object private

Inherited from CommandBase: lib/commands/commandbase.js:111

Returns and instance of the protocol buffer message builder for this command. This is determined via the pbRequestName passed to the constructor.

Returns:

Object: the builder for the protocol buffer message to be sent for this command

getRiakMessage

() Object private

Inherited from CommandBase: lib/commands/commandbase.js:88

Returns the encoded protobuf and message header.

Returns:

Object: object containing the header and encoded protobuf

onError

(
  • msg
  • data
)
protected

Inherited from CommandBase: lib/commands/commandbase.js:164

Called by RiakNode if an error occurs executing the command and all retries are exhausted.

Parameters:

  • msg String
    an error message
  • data Object
    additional error data

onRiakError

(
  • rpbErrorResp
)
protected

Inherited from CommandBase: lib/commands/commandbase.js:151

Called by RiakNode when a RpbErrorResp is received and all retries are exhausted. Commands may override this method.

Parameters:

  • rpbErrorResp Object
    the RpbErrorResp protocol buffer

onSuccess

(
  • pbResponseMessage
)
Boolean protected

Inherited from CommandBase: lib/commands/commandbase.js:139

Called by RiakNode when a response is received. Subclasses must override this method.

Parameters:

  • pbResponseMessage Object
    the protocol buffer received from riak

Returns:

Boolean: true if not streaming or the last response has been received, false otherwise.