Class: Airspace::Reader

Inherits:
Object
  • Object
show all
Extended by:
InfoKeys, Forwardable
Includes:
HasMetadata
Defined in:
lib/airspace/reader.rb

Overview

This is the main class that knows how to fetch and interpret the dataset. It is optimized for chunking/paging and allows you to only pull back specific pages (if desired.)

Constant Summary

Constants included from InfoKeys

InfoKeys::DATA_KEY, InfoKeys::METADATA_KEY, InfoKeys::SEPARATOR_CHAR

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(client, data:, key:, metadata:, serializer:) ⇒ Reader

Returns a new instance of Reader.



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# File 'lib/airspace/reader.rb', line 58

def initialize(client, data:, key:, metadata:, serializer:)
  @client     = client
  @key        = key
  @data       = data
  @metadata   = metadata
  @serializer = serializer

  freeze
end

Instance Attribute Details

#client ⇒ Object (readonly)

Returns the value of attribute client.



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# File 'lib/airspace/reader.rb', line 50

def client
  @client
end

#data ⇒ Object (readonly)

Returns the value of attribute data.



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# File 'lib/airspace/reader.rb', line 50

def data
  @data
end

#key ⇒ Object (readonly)

Returns the value of attribute key.



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# File 'lib/airspace/reader.rb', line 50

def key
  @key
end

#metadata ⇒ Object (readonly)

Returns the value of attribute metadata.



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# File 'lib/airspace/reader.rb', line 50

def metadata
  @metadata
end

#serializer ⇒ Object (readonly)

Returns the value of attribute serializer.



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# File 'lib/airspace/reader.rb', line 50

def serializer
  @serializer
end

Class Method Details

.find_by_id(client, id, options: {}) ⇒ Object 



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# File 'lib/airspace/reader.rb', line 20

def find_by_id(client, id, options: {})
  key        = ::Airspace::Key.new(id, prefix: options[:prefix])
  serializer = options[:serializer] || ::Airspace::Serializer.new
  hash       = fetch_and_transform(client, key, serializer)
  return nil unless hash

  metadata_args = hash[METADATA_KEY].map { |k, v| [k.to_sym, v] }.to_h

  new(
    client,
    data: hash[DATA_KEY],
    key: key,
    metadata: ::Airspace::Metadata.new(metadata_args),
    serializer: serializer
  )
end

Instance Method Details

#delete ⇒ Object 



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# File 'lib/airspace/reader.rb', line 86

def delete
  store.delete(key, page_count)
end

#page(number) ⇒ Object 



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# File 'lib/airspace/reader.rb', line 76

def page(number)
  return [] unless within_bounds?(number)

  page_index  = number - 1
  location    = chunker.locate(page_index)
  chunk       = store.chunk(key, location.chunk_index)

  chunk[location.page_index].map { |r| serializer.deserialize_row(r) }
end

#pages ⇒ Object 



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# File 'lib/airspace/reader.rb', line 68

def pages
  return [] unless page_count.positive?

  store.chunks(key, chunk_count).map do |chunk|
    chunk.map { |r| serializer.deserialize_row(r) }
  end
end