Class: Dynamoid::Adapter
- Inherits:
-
Object
- Object
- Dynamoid::Adapter
- Defined in:
- lib/dynamoid/adapter.rb
Overview
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.
Class Method Summary collapse
Instance Method Summary collapse
-
#adapter ⇒ Object
The actual adapter currently in use.
-
#benchmark(method, *args) { ... } ⇒ Object
Shows how long it takes a method to run on the adapter.
- #clear_cache! ⇒ Object
- #create_table(table_name, key, options = {}) ⇒ Object
-
#delete(table, ids, options = {}) ⇒ Object
Delete an item from a table.
- #delete_table(table_name, options = {}) ⇒ Object
-
#initialize ⇒ Adapter
constructor
A new instance of Adapter.
-
#method_missing(method, *args, &block) ⇒ Object
Delegate all methods that aren’t defind here to the underlying adapter.
-
#query(table_name, opts = {}) ⇒ Array
Query the DynamoDB table.
-
#read(table, ids, options = {}, &blk) ⇒ Object
Read one or many keys from the selected table.
-
#scan(table, query = {}, opts = {}) ⇒ Object
Scans a table.
- #tables ⇒ Object
-
#write(table, object, options = nil) ⇒ Object
Write an object to the adapter.
Constructor Details
#initialize ⇒ Adapter
Returns a new instance of Adapter.
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# File 'lib/dynamoid/adapter.rb', line 14 def initialize @adapter_ = Concurrent::Atom.new(nil) @tables_ = Concurrent::Atom.new(nil) end |
Dynamic Method Handling
This class handles dynamic methods through the method_missing method
#method_missing(method, *args, &block) ⇒ Object
Delegate all methods that aren’t defind here to the underlying adapter.
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# File 'lib/dynamoid/adapter.rb', line 156 def method_missing(method, *args, &block) return benchmark(method, *args) { adapter.send(method, *args, &block) } if adapter.respond_to?(method) super end |
Class Method Details
.adapter_plugin_class ⇒ Object
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# File 'lib/dynamoid/adapter.rb', line 181 def self.adapter_plugin_class unless Dynamoid.const_defined?(:AdapterPlugin) && Dynamoid::AdapterPlugin.const_defined?(Dynamoid::Config.adapter.camelcase) require "dynamoid/adapter_plugin/#{Dynamoid::Config.adapter}" end Dynamoid::AdapterPlugin.const_get(Dynamoid::Config.adapter.camelcase) end |
Instance Method Details
#adapter ⇒ Object
The actual adapter currently in use.
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# File 'lib/dynamoid/adapter.rb', line 29 def adapter unless @adapter_.value adapter = self.class.adapter_plugin_class.new adapter.connect! if adapter.respond_to?(:connect!) @adapter_.compare_and_set(nil, adapter) clear_cache! end @adapter_.value end |
#benchmark(method, *args) { ... } ⇒ Object
Shows how long it takes a method to run on the adapter. Useful for generating logged output.
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# File 'lib/dynamoid/adapter.rb', line 52 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 |
#clear_cache! ⇒ Object
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# File 'lib/dynamoid/adapter.rb', line 39 def clear_cache! @tables_.swap { |_value, _args| nil } end |
#create_table(table_name, key, options = {}) ⇒ Object
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# File 'lib/dynamoid/adapter.rb', line 124 def create_table(table_name, key, = {}) unless tables.include?(table_name) benchmark('Create Table') { adapter.create_table(table_name, key, ) } tables << table_name end end |
#delete(table, ids, options = {}) ⇒ Object
Delete an item from a table.
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# File 'lib/dynamoid/adapter.rb', line 98 def delete(table, ids, = {}) range_key = [: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, ) end end |
#delete_table(table_name, options = {}) ⇒ Object
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# File 'lib/dynamoid/adapter.rb', line 132 def delete_table(table_name, = {}) if tables.include?(table_name) benchmark('Delete Table') { adapter.delete_table(table_name, ) } idx = tables.index(table_name) tables.delete_at(idx) end end |
#query(table_name, opts = {}) ⇒ Array
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.
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# File 'lib/dynamoid/adapter.rb', line 177 def query(table_name, opts = {}) adapter.query(table_name, opts) end |
#read(table, ids, options = {}, &blk) ⇒ Object
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.
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# File 'lib/dynamoid/adapter.rb', line 84 def read(table, ids, = {}, &blk) if ids.respond_to?(:each) batch_get_item({ table => ids }, , &blk) else get_item(table, ids, ) end end |
#scan(table, query = {}, opts = {}) ⇒ Object
Scans a table. Generally quite slow; try to avoid using scan if at all possible.
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# File 'lib/dynamoid/adapter.rb', line 120 def scan(table, query = {}, opts = {}) benchmark('Scan', table, query) { adapter.scan(table, query, opts) } end |
#tables ⇒ Object
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# File 'lib/dynamoid/adapter.rb', line 19 def tables unless @tables_.value @tables_.swap { |_value, _args| benchmark('Cache Tables') { list_tables || [] } } end @tables_.value end |
#write(table, object, options = nil) ⇒ Object
Write an object to the adapter.
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# File 'lib/dynamoid/adapter.rb', line 68 def write(table, object, = nil) put_item(table, object, ) end |