Class: Corpshort::Backends::Dynamodb

Inherits:
Base
  • Object
show all
Defined in:
lib/corpshort/backends/dynamodb.rb

Instance Method Summary collapse

Methods inherited from Base

#rename_link

Constructor Details

#initialize(table:, region:) ⇒ Dynamodb

Returns a new instance of Dynamodb.



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# File 'lib/corpshort/backends/dynamodb.rb', line 10

def initialize(table:, region:)
  @table_name = table
  @region = region
end

Instance Method Details



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# File 'lib/corpshort/backends/dynamodb.rb', line 57

def delete_link(link)
  name = link.is_a?(String) ? link : link.name
  table.delete_item(
    key: {
      'name' => name,
    },
  )
end

#dynamodb ⇒ Object 



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# File 'lib/corpshort/backends/dynamodb.rb', line 19

def dynamodb
  @dynamodb ||= Aws::DynamoDB::Resource.new(region: @region)
end

#get_link(name) ⇒ Object 



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# File 'lib/corpshort/backends/dynamodb.rb', line 41

def get_link(name)
  item = table.query(
    limit: 1,
    select: 'ALL_ATTRIBUTES',
    key_condition_expression: '#n = :name',
    expression_attribute_names: {'#n' => 'name'},
    expression_attribute_values: {":name" => name},
  ).items.first

  if item && !item.empty?
    Link.new(item, backend: self)
  else
    nil
  end
end

#list_links(token: nil, limit: 30) ⇒ Object 



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# File 'lib/corpshort/backends/dynamodb.rb', line 76

def list_links(token: nil, limit: 30)
  partition, last_key = parse_token(token)
  limit.times do
    result = table.query(
      index_name: 'updated_at_partition-updated_at-index',
      select: 'ALL_PROJECTED_ATTRIBUTES',
      scan_index_forward: false,
      exclusive_start_key: last_key ? last_key : nil,
      key_condition_expression: 'updated_at_partition = :partition',
      expression_attribute_values: {":partition" => partition.strftime('%Y-%m')},
      limit: limit,
    )

    unless result.items.empty?
      return [result.items.map{ |_| _['name'] }, result.last_evaluated_key&.values_at('updated_at_partition', 'name', 'updated_at')&.join(?:)]
    end

    partition = partition.to_date.prev_month
    last_key = nil
    sleep 0.05
  end
  return [[], nil]
end

#list_links_by_url(url) ⇒ Object 



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# File 'lib/corpshort/backends/dynamodb.rb', line 66

def list_links_by_url(url)
  table.query(
    index_name: 'url-updated_at-index',
    select: 'ALL_PROJECTED_ATTRIBUTES',
    key_condition_expression: '#u = :url',
    expression_attribute_names: {"#u" => 'url'},
    expression_attribute_values: {":url" => url},
  ).items.map { |_| _['name'] }
end

#put_link(link, create_only: false) ⇒ Object 



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# File 'lib/corpshort/backends/dynamodb.rb', line 23

def put_link(link, create_only: false)
  table.update_item(
    key: {
      'name' => link.name,
    },
    update_expression: 'SET #u = :url, updated_at_partition = :ts_partition, updated_at = :updated_at',
    condition_expression: create_only ? 'attribute_not_exists(#n)' : nil,
    expression_attribute_names: create_only ? {'#u' => 'url', '#n' => 'name'} : {'#u' => 'url'},
    expression_attribute_values: {
      ':url' => link.url,
      ':ts_partition' => ts_partition(link.updated_at),
      ':updated_at' => link.updated_at.iso8601,
    },
  )
rescue Aws::DynamoDB::Errors::ConditionalCheckFailedException
  raise ConflictError
end

#table ⇒ Object 



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# File 'lib/corpshort/backends/dynamodb.rb', line 15

def table
  @table ||= dynamodb.table(@table_name)
end