Class: Aws::Record::TableConfig
- Inherits:
-
Object
- Object
- Aws::Record::TableConfig
- Defined in:
- lib/aws-record/record/table_config.rb
Overview
Aws::Record::TableConfig
provides a DSL for describing and modifying the remote configuration of your DynamoDB tables. A table configuration object can perform intelligent comparisons and incremental migrations versus the current remote configuration, if the table exists, or do a full create if it does not. In this manner, table configuration becomes fully declarative.
Instance Attribute Summary collapse
-
#client ⇒ Object
Returns the value of attribute client.
Class Method Summary collapse
-
.define(&block) ⇒ Object
Creates a new table configuration, using a DSL in the provided block.
Instance Method Summary collapse
-
#compatible? ⇒ Boolean
Checks the remote table for compatibility.
-
#exact_match? ⇒ Boolean
Checks against the remote table’s configuration.
-
#migrate! ⇒ Object
Performs a migration, if needed, against the remote table.
Instance Attribute Details
#client ⇒ Object
Returns the value of attribute client.
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# File 'lib/aws-record/record/table_config.rb', line 92 def client @client end |
Class Method Details
.define(&block) ⇒ Object
Creates a new table configuration, using a DSL in the provided block. The DSL has the following methods:
-
#model_class
A class name reference to theAws::Record
model class. -
#read_capacity_units
Sets the read capacity units for the table. -
#write_capacity_units
Sets the write capacity units for the table. -
#global_secondary_index(index_symbol, &block) Defines a global secondary index with capacity attributes in a block:
-
#read_capacity_units
Sets the read capacity units for the index. -
#write_capacity_units
Sets the write capacity units for the index.
-
-
#ttl_attribute
Sets the attribute ID to be used as the TTL attribute, and if present, TTL will be enabled for the table. -
#billing_mode
Sets the billing mode, with the current supported options being “PROVISIONED” and “PAY_PER_REQUEST”. If using “PAY_PER_REQUEST” you must not set provisioned throughput values, and if using “PROVISIONED” you must set provisioned throughput values. Default assumption is “PROVISIONED”.
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# File 'lib/aws-record/record/table_config.rb', line 146 def define(&block) cfg = TableConfig.new cfg.instance_eval(&block) cfg.configure_client cfg end |
Instance Method Details
#compatible? ⇒ Boolean
Checks the remote table for compatibility. Similar to #exact_match?
, this will return false
if the remote table does not exist. It also checks the keys, declared global secondary indexes, declared attribute definitions, and throughput for exact matches. However, if the remote end has additional attribute definitions and global secondary indexes not defined in your config, will still return true
. This allows for a check that is friendly to single table inheritance use cases.
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# File 'lib/aws-record/record/table_config.rb', line 269 def compatible? resp = @client.describe_table(table_name: @model_class.table_name) _compatible_check(resp) && _ttl_compatibility_check rescue DynamoDB::Errors::ResourceNotFoundException false end |
#exact_match? ⇒ Boolean
Checks against the remote table’s configuration. If the remote table does not exist, guaranteed false
. Otherwise, will check if the remote throughput, keys, attribute definitions, and global secondary indexes are exactly equal to your declared configuration.
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# File 'lib/aws-record/record/table_config.rb', line 282 def exact_match? resp = @client.describe_table(table_name: @model_class.table_name) _throughput_equal(resp) && _keys_equal(resp) && _ad_equal(resp) && _gsi_equal(resp) && _ttl_match_check rescue DynamoDB::Errors::ResourceNotFoundException false end |
#migrate! ⇒ Object
Performs a migration, if needed, against the remote table. If #compatible?
would return true, the remote table already has the same throughput, key schema, attribute definitions, and global secondary indexes, so no further API calls are made. Otherwise, a DynamoDB table will be created or updated to match your declared configuration.
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# File 'lib/aws-record/record/table_config.rb', line 212 def migrate! _validate_required_configuration begin resp = @client.describe_table(table_name: @model_class.table_name) if _compatible_check(resp) nil else # Gotcha: You need separate migrations for indexes and throughput unless _throughput_equal(resp) @client.update_table(_update_throughput_opts(resp)) @client.wait_until( :table_exists, table_name: @model_class.table_name ) end unless _gsi_superset(resp) @client.update_table(_update_index_opts(resp)) @client.wait_until( :table_exists, table_name: @model_class.table_name ) end end rescue DynamoDB::Errors::ResourceNotFoundException # Code Smell: Exception as control flow. # Can I use SDK ability to skip raising an exception for this? @client.create_table(_create_table_opts) @client.wait_until(:table_exists, table_name: @model_class.table_name) end # At this stage, we have a table and need to check for after-effects to # apply. # First up is TTL attribute. Since this migration is not exact match, # we will only alter TTL status if we have a TTL attribute defined. We # may someday support explicit TTL deletion, but we do not yet do this. return unless @ttl_attribute return if _ttl_compatibility_check client.update_time_to_live( table_name: @model_class.table_name, time_to_live_specification: { enabled: true, attribute_name: @ttl_attribute } ) # Else TTL is compatible and we are done. # Else our work is done. end |