Elastic

v3.5.0

Elastic v3.5.0 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

child_spec(arg)

Returns a specification to start this module under a supervisor

init(state)

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

next_page(pid)

Fetches the next page of results and returns a scroll ID

results(pid)

Returns the results of the current scroll location

start_link(opts)

Starts an Elastic.Scroller server

Link to this section Functions

Link to this function

child_spec(arg) View Source

Returns a specification to start this module under a supervisor.

See Supervisor.

Link to this function

init(state) View Source 
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.

args 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 handle_info(:timeout, state) will be called after timeout milliseconds if no messages are received within the timeout.

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.

Link to this function

next_page(pid) View Source 
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)
Link to this function

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

Returns the results of the current scroll location.

Elastic.Scroller.results(pid)
Link to this function

start_link(opts) View Source 
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.