Class: ElasticGraph::GraphQL::DatastoreResponse::SearchResponse

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Includes:
Enumerable
Defined in:
lib/elastic_graph/graphql/datastore_response/search_response.rb

Overview

Represents a search response from the datastore. Exposes both the raw metadata provided by the datastore and the collection of documents. Can be treated as a collection of documents when you don’t care about the metadata.

Constant Summary collapse

EXCLUDED_METADATA_KEYS = 
%w[hits aggregations].freeze
RAW_EMPTY =

Benign empty response that can be used in place of datastore response errors as needed.

{"hits" => {"hits" => [], "total" => {"value" => 0}}}.freeze
EMPTY = 
build(RAW_EMPTY)

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.build(raw_data, decoded_cursor_factory: DecodedCursor::Factory::Null, aggregations_unavailable_reason: nil) ⇒ Object 



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# File 'lib/elastic_graph/graphql/datastore_response/search_response.rb', line 31

def self.build(raw_data, decoded_cursor_factory: DecodedCursor::Factory::Null, aggregations_unavailable_reason: nil)
  documents = raw_data.fetch("hits").fetch("hits").map do |doc|
    Document.build(doc, decoded_cursor_factory: decoded_cursor_factory)
  end

  metadata = raw_data.except(*EXCLUDED_METADATA_KEYS)
  metadata["hits"] = raw_data.fetch("hits").except("hits")

  # `hits.total` is exposed as an object like:
  #
  # {
  #   "value" => 200,
  #   "relation" => "eq", # or "gte"
  # }
  #
  # This allows it to provide a lower bound on the number of hits, rather than having
  # to give an exact count. We may want to handle the `gte` case differently at some
  # point but for now we just use the value as-is.
  #
  # In the case where `track_total_hits` flag is set to `false`, `hits.total` field will be completely absent.
  # This means the client intentionally chose not to query the total doc count, and `total_document_count` will be nil.
  # In this case, we will throw an exception if the client later tries to access `total_document_count`.
  total_document_count = metadata.dig("hits", "total", "value")

  new(
    raw_data:,
    metadata:,
    documents:,
    total_document_count:,
    aggregations_unavailable_reason:,
    decoded_cursor_factory:
  )
end

.synthesize_from_ids(index, ids, decoded_cursor_factory: DecodedCursor::Factory::Null) ⇒ Object 



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# File 'lib/elastic_graph/graphql/datastore_response/search_response.rb', line 65

def self.synthesize_from_ids(index, ids, decoded_cursor_factory: DecodedCursor::Factory::Null)
  hits = ids.map do |id|
    {
      "_index" => index,
      "_type" => "_doc",
      "_id" => id,
      "_score" => nil,
      "_source" => {"id" => id},
      "sort" => [id]
    }
  end

  raw_data = {
    "took" => 0,
    "timed_out" => false,
    "_shards" => {
      "total" => 0,
      "successful" => 0,
      "skipped" => 0,
      "failed" => 0
    },
    "hits" => {
      "total" => {
        "value" => ids.size,
        "relation" => "eq"
      },
      "max_score" => nil,
      "hits" => hits
    }
  }

  build(raw_data, decoded_cursor_factory: decoded_cursor_factory)
end

Instance Method Details

#aggregations ⇒ Object 



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# File 'lib/elastic_graph/graphql/datastore_response/search_response.rb', line 138

def aggregations
  if (reason = aggregations_unavailable_reason)
    raise Errors::AggregationsUnavailableError, "Aggregations are unavailable on this search response: #{reason}."
  end

  raw_data["aggregations"] || {}
end

#docs_description ⇒ Object 



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# File 'lib/elastic_graph/graphql/datastore_response/search_response.rb', line 130

def docs_description
  (documents.size < 3) ? documents.inspect : "[#{documents.first}, ..., #{documents.last}]"
end

#filter_results(field_path, values, size) ⇒ Object

Returns a response filtered to results that have matching ‘values` at the given `field_path`, limiting the results to the first `size` results.

This is designed for use in situations where we have N different datastore queries which are identical except for differing filter values. For efficiency, we combine those queries into a single query that filters on the set union of values. We can then use this method to “split” the single response into what the separate responses would have been if we hadn’t combined into a single query.



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# File 'lib/elastic_graph/graphql/datastore_response/search_response.rb', line 110

def filter_results(field_path, values, size)
  filter =
    if field_path == ["id"]
      # `id` filtering is a very common case, and we want to avoid having to request
      # `id` within `_source`, given it's available as `_id`.
      ->(hit) { values.include?(hit.fetch("_id")) }
    else
      ->(hit) { values.intersect?(Support::HashUtil.fetch_leaf_values_at_path(hit.fetch("_source"), field_path).to_set) }
    end

  hits = raw_data.fetch("hits").fetch("hits").select(&filter).first(size)
  updated_raw_data = Support::HashUtil.deep_merge(raw_data, {"hits" => {"hits" => hits, "total" => nil}})

  SearchResponse.build(
    updated_raw_data,
    decoded_cursor_factory: decoded_cursor_factory,
    aggregations_unavailable_reason: "aggregations cannot be provided accurately on a search response filtered in memory"
  )
end

#to_s ⇒ Object Also known as: inspect 



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# File 'lib/elastic_graph/graphql/datastore_response/search_response.rb', line 146

def to_s
  "#<#{self.class.name} size=#{documents.size} #{docs_description}>"
end

#total_document_count(default: nil) ⇒ Object 



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# File 'lib/elastic_graph/graphql/datastore_response/search_response.rb', line 134

def total_document_count(default: nil)
  super() || default || raise(Errors::CountUnavailableError, "#{__method__} is unavailable; set `query.total_document_count_needed = true` to make it available")
end