Class: SimpleDB::Driver

Inherits:
Object show all
Defined in:
lib/sdbcli/sdb-driver.rb

Defined Under Namespace

Classes: Iterator

Constant Summary collapse

MAX_NUMBER_SUBMITTED_ITEMS = 
25

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(accessKeyId, secretAccessKey, endpoint = 'sdb.amazonaws.com') ⇒ Driver

Returns a new instance of Driver.



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# File 'lib/sdbcli/sdb-driver.rb', line 13

def initialize(accessKeyId, secretAccessKey, endpoint = 'sdb.amazonaws.com')
  @client = Client.new(accessKeyId, secretAccessKey, endpoint)
  @select_expr = nil
  @next_token = nil
  @current_token = nil
  @current_page = 1
end

Instance Attribute Details

#iteratable ⇒ Object

Returns the value of attribute iteratable.



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# File 'lib/sdbcli/sdb-driver.rb', line 11

def iteratable
  @iteratable
end

Instance Method Details

#create_domain(domain_name) ⇒ Object

domain action



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# File 'lib/sdbcli/sdb-driver.rb', line 39

def create_domain(domain_name)
  @client.create_domain(domain_name)
end

#current_list(consistent = false) ⇒ Object 



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# File 'lib/sdbcli/sdb-driver.rb', line 155

def current_list(consistent = false)
  unless @select_expr
    return []
  end

  params = {:SelectExpression => @select_expr, :ConsistentRead => consistent}
  items = []

  iterate(:select, params, @current_token || :first) do |doc|
    doc.css('Item').map do |i|
      items << [i.at_css('Name').content, attrs_to_hash(i)]
    end
  end

  return items
end

#current_page ⇒ Object 



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# File 'lib/sdbcli/sdb-driver.rb', line 262

def current_page
  @current_page
end

#delete(domain_name, items = {}) ⇒ Object 



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# File 'lib/sdbcli/sdb-driver.rb', line 266

def delete(domain_name, items = {})
  until (chunk = items.slice!(0, MAX_NUMBER_SUBMITTED_ITEMS)).empty?
    params = {}
    i = j = 0

    chunk.each do |item_name, attrs|
      i += 1
      params["Item.#{i}.ItemName"] = item_name

      (attrs || []).each do |attr_name, values|
        [values].flatten.each do |v|
          j += 1
          params["Item.#{i}.Attribute.#{j}.Name"] = attr_name
          params["Item.#{i}.Attribute.#{j}.Value"] = v if v
        end
      end
    end

    @client.batch_delete_attributes(domain_name, params)
  end
end

#describe(domain_name) ⇒ Object 



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# File 'lib/sdbcli/sdb-driver.rb', line 329

def describe(domain_name)
  doc = @client.domain_metadata(domain_name)
  h = {}

  doc.at_css('DomainMetadataResult').children.each do |child|
    h[child.name] = child.content
  end

  return h
end

#drop_domain(domain_name) ⇒ Object 



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# File 'lib/sdbcli/sdb-driver.rb', line 55

def drop_domain(domain_name)
  @client.delete_domain(domain_name)
end

#endpoint ⇒ Object 



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# File 'lib/sdbcli/sdb-driver.rb', line 21

def endpoint
  @client.endpoint
end

#endpoint=(v) ⇒ Object 



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# File 'lib/sdbcli/sdb-driver.rb', line 25

def endpoint=(v)
  @client.endpoint = v
end

#get(domain_name, item_name, attr_names = [], consistent = false) ⇒ Object 



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# File 'lib/sdbcli/sdb-driver.rb', line 107

def get(domain_name, item_name, attr_names = [], consistent = false)
  params = {:ConsistentRead => consistent}
  attr_names.each_with_index {|name, i| params["AttributeName.#{i}"] = name }
  doc = @client.get_attributes(domain_name, item_name, params)
  attrs_to_hash(doc)
end

#insert(domain_name, items = {}) ⇒ Object

attr action



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# File 'lib/sdbcli/sdb-driver.rb', line 61

def insert(domain_name, items = {})
  until (chunk = items.slice!(0, MAX_NUMBER_SUBMITTED_ITEMS)).empty?
    params = {}
    i = j = 0

    chunk.each do |item_name, attrs|
      i += 1
      params["Item.#{i}.ItemName"] = item_name

      (attrs || {}).each do |attr_name, values|
        [values].flatten.each do |v|
          j += 1
          params["Item.#{i}.Attribute.#{j}.Name"] = attr_name
          params["Item.#{i}.Attribute.#{j}.Value"] = v
          params["Item.#{i}.Attribute.#{j}.Replace"] = false
        end
      end
    end

    @client.batch_put_attributes(domain_name, params)
  end
end

#next_list(consistent = false) ⇒ Object 



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# File 'lib/sdbcli/sdb-driver.rb', line 134

def next_list(consistent = false)
  unless @select_expr and @next_token
    return []
  end

  params = {:SelectExpression => @select_expr, :ConsistentRead => consistent}
  items = []

  token = iterate(:select, params, @next_token) do |doc|
    doc.css('Item').map do |i|
      items << [i.at_css('Name').content, attrs_to_hash(i)]
    end
  end

  @current_token = @next_token
  @next_token = token
  @current_page += 1

  return items
end

#page_num ⇒ Object 



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# File 'lib/sdbcli/sdb-driver.rb', line 288

def page_num
  return nil unless @select_expr

  ss = StringScanner.new(@select_expr)
  domain_name = nil

  until ss.eos?
    if ss.scan(/[^F`'"|!]+/i) #'
    elsif ss.scan(/`(?:[^`]|``)*`/)
    elsif ss.scan(/'(?:[^']|'')*'/) #'
    elsif ss.scan(/"(?:[^"]|"")*"/) #"
    elsif (tok = ss.scan /FROM\b\s*[^\s]+/i)
      domain_name = tok.split(/\b/, 2).last
      break
    elsif ss.scan(/./)
    end
  end

  return nil unless domain_name
  domain_name.strip!.gsub!(/`([^`]+)`/, '\1')

  item_count = describe(domain_name)['ItemCount'].to_f

  ss = StringScanner.new(@select_expr)
  limit = 100

  until ss.eos?
    if ss.scan(/[^`'"L]+/i) #'
    elsif ss.scan( /`(?:[^`]|``)*`/)
    elsif ss.scan(/'(?:[^']|'')*'/) #'
    elsif ss.scan(/"(?:[^"]|"")*"/) #"
    elsif (tok = ss.scan /LIMIT\s+\d\b/i)
      limit = tok.split(/\s+/).last.to_i
      break
    elsif ss.scan(/./)
    end
  end

  return (item_count / limit).ceil
end

#page_to(page, consistent = false) ⇒ Object 



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# File 'lib/sdbcli/sdb-driver.rb', line 177

def page_to(page, consistent = false)
  if page.zero?
    raise SimpleDB::Error, "Invalid page number: #{page}"
  end

  unless @select_expr
    return []
  end

  if page < 0
    n = page_num
    return [] unless n
    page =  n + 1 + page
  end

  ss = StringScanner.new(@select_expr.dup)
  limit = 100

  until ss.eos?
    if ss.scan(/[^`'"L]+/i) #'
    elsif ss.scan( /`(?:[^`]|``)*`/)
    elsif ss.scan(/'(?:[^']|'')*'/) #'
    elsif ss.scan(/"(?:[^"]|"")*"/) #"
    elsif (tok = ss.scan /LIMIT\s+\d\b/i)
      limit = tok.split(/\s+/).last.to_i
      break
    elsif ss.scan(/./)
    end
  end

  params = {:SelectExpression => @select_expr, :ConsistentRead => consistent}
  items = []

  token = (page > 1) ? SimpleDB::TokenGenerator.next_token(limit, page) : :first

  new_token = iterate(:select, params, token) do |doc|
    doc.css('Item').map do |i|
      items << [i.at_css('Name').content, attrs_to_hash(i)]
    end
  end

  @current_token = token
  @next_token = new_token
  @current_page = page

  return items
end

#prev_list(consistent = false) ⇒ Object 



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# File 'lib/sdbcli/sdb-driver.rb', line 225

def prev_list(consistent = false)
  unless @select_expr and @current_page > 1
    return []
  end

  ss = StringScanner.new(@select_expr.dup)
  limit = 100

  until ss.eos?
    if ss.scan(/[^`'"L]+/i) #'
    elsif ss.scan( /`(?:[^`]|``)*`/)
    elsif ss.scan(/'(?:[^']|'')*'/) #'
    elsif ss.scan(/"(?:[^"]|"")*"/) #"
    elsif (tok = ss.scan /LIMIT\s+\d\b/i)
      limit = tok.split(/\s+/).last.to_i
    elsif ss.scan(/./)
    end
  end

  params = {:SelectExpression => @select_expr, :ConsistentRead => consistent}
  items = []

  token = (@current_page > 2) ? SimpleDB::TokenGenerator.next_token(limit, @current_page - 1) : :first

  new_token = iterate(:select, params, token) do |doc|
    doc.css('Item').map do |i|
      items << [i.at_css('Name').content, attrs_to_hash(i)]
    end
  end

  @current_token = token
  @next_token = new_token
  @current_page -= 1

  return items
end

#select(expr, consistent = false, persist = false) ⇒ Object 



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# File 'lib/sdbcli/sdb-driver.rb', line 114

def select(expr, consistent = false, persist = false)
  params = {:SelectExpression => expr, :ConsistentRead => consistent}
  items = []

  token = iterate(:select, params) do |doc|
    doc.css('Item').map do |i|
      items << [i.at_css('Name').content, attrs_to_hash(i)]
    end
  end

  if persist
    @select_expr = expr
    @current_token = nil
    @next_token = token
    @current_page = 1
  end

  return items
end

#show_domains ⇒ Object 



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# File 'lib/sdbcli/sdb-driver.rb', line 43

def show_domains
  domains = []

  iterate(:list_domains) do |doc|
    doc.css('DomainName').each do |i|
      domains << i.content
    end
  end

  return domains
end

#tail(domain_name, consistent = false) ⇒ Object 



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# File 'lib/sdbcli/sdb-driver.rb', line 172

def tail(domain_name, consistent = false)
  @select_expr = "SELECT * FROM #{domain_name}"
  page_to(-1, consistent)
end

#timeout ⇒ Object 



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# File 'lib/sdbcli/sdb-driver.rb', line 29

def timeout
  @client.timeout
end

#timeout=(v) ⇒ Object 



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# File 'lib/sdbcli/sdb-driver.rb', line 33

def timeout=(v)
  @client.timeout = v
end

#update(domain_name, items = {}) ⇒ Object 



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# File 'lib/sdbcli/sdb-driver.rb', line 84

def update(domain_name, items = {})
  until (chunk = items.slice!(0, MAX_NUMBER_SUBMITTED_ITEMS)).empty?
    params = {}
    i = j = 0

    chunk.each do |item_name, attrs|
      i += 1
      params["Item.#{i}.ItemName"] = item_name

      (attrs || {}).each do |attr_name, values|
        [values].flatten.each do |v|
          j += 1
          params["Item.#{i}.Attribute.#{j}.Name"] = attr_name
          params["Item.#{i}.Attribute.#{j}.Value"] = v
          params["Item.#{i}.Attribute.#{j}.Replace"] = true
        end
      end
    end

    @client.batch_put_attributes(domain_name, params)
  end
end