Elastic v3.5.1 Elastic.Scroller View Source

Provides an API for working with Elastic Search's Scroll API

Example

{:ok, pid} = Elastic.Scroller.start_link(%{index: "answer"})
# get the first "page" of results
Elastic.Scroller.results(pid)
# Request the second page
Elastic.Scroller.next_page(pid)
# get the second "page" of results
Elastic.Scroller.results(pid)

Then you can choose to kill the search context yourself... keeping in mind of course that Elastic Search will do this automatically after the keepalive (default of 1 minute) expires for the scroll.

Elastic.Scroller.clear(pid)

Link to this section Summary

Functions

Returns a specification to start this module under a supervisor.

Invoked when the server is started. start_link/3 or start/3 will block until it returns.

Fetches the next page of results and returns a scroll ID.

Returns the results of the current scroll location.

Starts an Elastic.Scroller server.

Link to this section Functions

Returns a specification to start this module under a supervisor.

See Supervisor.

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init(state)

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init(%{
  index: String.t(),
  body: map(),
  size: pos_integer(),
  keepalive: String.t()
}) :: {:ok, pid()} | {:stop, String.t()}

Invoked when the server is started. start_link/3 or start/3 will block until it returns.

init_arg is the argument term (second argument) passed to start_link/3.

Returning {:ok, state} will cause start_link/3 to return {:ok, pid} and the process to enter its loop.

Returning {:ok, state, timeout} is similar to {:ok, state}, except that it also sets a timeout. See the "Timeouts" section in the module documentation for more information.

Returning {:ok, state, :hibernate} is similar to {:ok, state} except the process is hibernated before entering the loop. See c:handle_call/3 for more information on hibernation.

Returning {:ok, state, {:continue, continue}} is similar to {:ok, state} except that immediately after entering the loop the c:handle_continue/2 callback will be invoked with the value continue as first argument.

Returning :ignore will cause start_link/3 to return :ignore and the process will exit normally without entering the loop or calling c:terminate/2. If used when part of a supervision tree the parent supervisor will not fail to start nor immediately try to restart the GenServer. The remainder of the supervision tree will be started and so the GenServer should not be required by other processes. It can be started later with Supervisor.restart_child/2 as the child specification is saved in the parent supervisor. The main use cases for this are:

  • The GenServer is disabled by configuration but might be enabled later.
  • An error occurred and it will be handled by a different mechanism than the Supervisor. Likely this approach involves calling Supervisor.restart_child/2 after a delay to attempt a restart.

Returning {:stop, reason} will cause start_link/3 to return {:error, reason} and the process to exit with reason reason without entering the loop or calling c:terminate/2.

Callback implementation for GenServer.init/1.

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next_page(pid)

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next_page(pid()) ::
  {:ok, String.t()}
  | {:error, :search_context_not_found, map()}
  | {:error, String.t()}

Fetches the next page of results and returns a scroll ID.

To retrieve the results that come from this request, make a call to Elastic.Scroller.results/1.

Elastic.Scroller.next_page(pid)
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results(pid)

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results(pid()) :: [map()]

Returns the results of the current scroll location.

Elastic.Scroller.results(pid)
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start_link(opts)

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start_link(%{
  :index => String.t(),
  optional(:body) => map(),
  optional(:size) => pos_integer(),
  optional(:keepalive) => String.t()
}) :: {:ok, pid()}

Starts an Elastic.Scroller server.

For usage information refer to the documentation at the top of this module.