class Dynamoid::Adapter
Adapter’s value-add: 1) For the rest of Dynamoid
, the gateway to DynamoDB. 2) Allows switching ‘config.adapter` to ease development of a new adapter. 3) Caches the list of tables Dynamoid
knows about. @private
Public Class Methods
# File lib/dynamoid/adapter.rb, line 189 def self.adapter_plugin_class Dynamoid::AdapterPlugin.const_get(Dynamoid::Config.adapter.camelcase) end
# File lib/dynamoid/adapter.rb, line 13 def initialize @adapter_ = Concurrent::Atom.new(nil) @tables_ = Concurrent::Atom.new(nil) end
Public Instance Methods
The actual adapter currently in use.
@since 0.2.0
# File lib/dynamoid/adapter.rb, line 28 def adapter unless @adapter_.value adapter = self.class.adapter_plugin_class.new adapter.connect! @adapter_.compare_and_set(nil, adapter) clear_cache! end @adapter_.value end
Shows how long it takes a method to run on the adapter. Useful for generating logged output.
@param [Symbol|String] method the name of the method to appear in the log @param [Array] args the arguments to the method to appear in the log @yield the actual code to benchmark
@return the result of the yield
@since 0.2.0
# File lib/dynamoid/adapter.rb, line 51 def benchmark(method, *args) start = Time.now result = yield Dynamoid.logger.debug "(#{((Time.now - start) * 1000.0).round(2)} ms) #{method.to_s.split('_').collect(&:upcase).join(' ')}#{" - #{args.inspect}" unless args.nil? || args.empty?}" result end
# File lib/dynamoid/adapter.rb, line 38 def clear_cache! @tables_.swap { |_value, _args| nil } end
# File lib/dynamoid/adapter.rb, line 125 def create_table(table_name, key, options = {}) unless tables.include?(table_name) result = nil benchmark('Create Table') { result = adapter.create_table(table_name, key, options) } tables << table_name result else false end end
Delete an item from a table.
@param [String] table the name of the table to write the object to @param [String, Array] ids to delete; can also be a string of just one id @param [Hash] options allowed only range_key
- range key or array of
range keys of the record to delete, can also be a string of just one range_key, and +conditions+
# File lib/dynamoid/adapter.rb, line 99 def delete(table, ids, options = {}) range_key = options[:range_key] # array of range keys that matches the ids passed in if ids.respond_to?(:each) ids = if range_key.respond_to?(:each) # turn ids into array of arrays each element being hash_key, range_key ids.each_with_index.map { |id, i| [id, range_key[i]] } else range_key ? ids.map { |id| [id, range_key] } : ids end batch_delete_item(table => ids) else delete_item(table, ids, options) end end
@since 0.2.0
# File lib/dynamoid/adapter.rb, line 137 def delete_table(table_name, options = {}) if tables.include?(table_name) benchmark('Delete Table') { adapter.delete_table(table_name, options) } idx = tables.index(table_name) tables.delete_at(idx) end end
Delegate all methods that aren’t defind here to the underlying adapter.
@since 0.2.0
# File lib/dynamoid/adapter.rb, line 157 def method_missing(method, *args, &block) # Don't use keywork arguments delegating (with **kw). It works in # different way in different Ruby versions: <= 2.6, 2.7, 3.0 and in some # future 3.x versions. Providing that there are no downstream methods # with keyword arguments in adapter. # # https://eregon.me/blog/2019/11/10/the-delegation-challenge-of-ruby27.html return benchmark(method, *args) { adapter.send(method, *args, &block) } if adapter.respond_to?(method) super end
Query the DynamoDB table. This employs DynamoDB’s indexes so is generally faster than scanning, but is only really useful for range queries, since it can only find by one hash key at once. Only provide one range key to the hash.
@param [String] table_name the name of the table @param [Hash] opts the options to query the table with @option opts [String] :hash_value the value of the hash key to find @option opts [Range] :range_value find the range key within this range @option opts [Number] :range_greater_than find range keys greater than this @option opts [Number] :range_less_than find range keys less than this @option opts [Number] :range_gte find range keys greater than or equal to this @option opts [Number] :range_lte find range keys less than or equal to this
@return [Array] an array of all matching items
# File lib/dynamoid/adapter.rb, line 185 def query(table_name, opts = {}) adapter.query(table_name, opts) end
Read one or many keys from the selected table. This method intelligently calls batch_get or get on the underlying adapter depending on whether ids is a range or a single key. If a range key is present, it will also interpolate that into the ids so that the batch get will acquire the correct record.
@param [String] table the name of the table to write the object to @param [String, Array] ids to fetch; can also be a string of just one id @param [Hash] options Passed to the underlying query. The :range_key option is required whenever the table has a range key,
unless multiple ids are passed in.
@since 0.2.0
# File lib/dynamoid/adapter.rb, line 83 def read(table, ids, options = {}, &blk) if ids.respond_to?(:each) batch_get_item({ table => ids }, options, &blk) else get_item(table, ids, options) end end
Scans a table. Generally quite slow; try to avoid using scan if at all possible.
@param [String] table the name of the table to write the object to @param [Hash] query a hash of attributes: matching records will be returned by the scan
@since 0.2.0
# File lib/dynamoid/adapter.rb, line 121 def scan(table, query = {}, opts = {}) benchmark('Scan', table, query) { adapter.scan(table, query, opts) } end
# File lib/dynamoid/adapter.rb, line 18 def tables unless @tables_.value @tables_.swap { |_value, _args| benchmark('Cache Tables') { list_tables || [] } } end @tables_.value end
Write an object to the adapter.
@param [String] table the name of the table to write the object to @param [Object] object the object itself @param [Hash] options Options that are passed to the put_item call
@return [Object] the persisted object
@since 0.2.0
# File lib/dynamoid/adapter.rb, line 67 def write(table, object, options = nil) put_item(table, object, options) end