class RedisPagination::Paginator::SortedSetPaginator

Public Class Methods

new(key, options = {}) click to toggle source

Initialize a new instance with a given Redis key and options.

@param key [String] Redis sorted set key. @param options [Hash] Options for paginator.

# File lib/redis_pagination/paginator/sorted_set_paginator.rb, line 8
def initialize(key, options = {})
  @key = key
end

Public Instance Methods

all(options = {}) click to toggle source

Retrieve all items for key.

@param options [Hash] Options. Valid options are :with_scores and :reverse.

:with_scores controls whether the score is returned along with the item. Default is +true+.
:reverse controls whether to return items in highest-to-lowest (+true+) or loweest-to-highest order (+false+). Default is +true+.

@return a Hash containing :current_page, :total_pages, :total_items and :items.

# File lib/redis_pagination/paginator/sorted_set_paginator.rb, line 66
def all(options = {})
  with_scores = options.has_key?(:with_scores) ? options[:with_scores] : true
  reverse = options.has_key?(:reverse) ? options[:reverse] : true

  {
    :current_page => 1,
    :total_pages => 1,
    :total_items => total_items,
    :items => if reverse
      RedisPagination.redis.zrevrange(@key, 0, -1, :with_scores => with_scores)
    else
      RedisPagination.redis.zrange(@key, 0, -1, :with_scores => with_scores)
    end
  }
end
page(page, options = {}) click to toggle source

Retrieve a page of items for key.

@param page [int] Page of items to retrieve. @param options [Hash] Options. Valid options are :page_size, :with_scores and :reverse.

:page_size controls the page size for the call. Default is +RedisPagination.page_size+.
:with_scores controls whether the score is returned along with the item. Default is +true+.
:reverse controls whether to return items in highest-to-lowest (+true+) or loweest-to-highest order (+false+). Default is +true+.

@return a Hash containing :current_page, :total_pages, :total_items and :items.

# File lib/redis_pagination/paginator/sorted_set_paginator.rb, line 37
def page(page, options = {})
  current_page = page < 1 ? 1 : page
  index_for_redis = current_page - 1
  page_size = options[:page_size] || RedisPagination.page_size
  starting_offset = index_for_redis * page_size
  ending_offset = (starting_offset + page_size) - 1

  with_scores = options.has_key?(:with_scores) ? options[:with_scores] : true
  reverse = options.has_key?(:reverse) ? options[:reverse] : true

  {
    :current_page => current_page,
    :total_pages => total_pages(page_size),
    :total_items => total_items,
    :items => if reverse
      RedisPagination.redis.zrevrange(@key, starting_offset, ending_offset, :with_scores => with_scores)
    else
      RedisPagination.redis.zrange(@key, starting_offset, ending_offset, :with_scores => with_scores)
    end
  }
end
total_items() click to toggle source

Return the total number of items for key.

@return the total number of items for key.

# File lib/redis_pagination/paginator/sorted_set_paginator.rb, line 24
def total_items
  RedisPagination.redis.zcard(@key)
end
total_pages(page_size = RedisPagination.page_size) click to toggle source

Return the total number of pages for key.

@param page_size [int] Page size to calculate total number of pages.

@return the total number of pages for key.

# File lib/redis_pagination/paginator/sorted_set_paginator.rb, line 17
def total_pages(page_size = RedisPagination.page_size)
  (RedisPagination.redis.zcard(@key) / page_size.to_f).ceil
end