Class: CloudKit::Store

Inherits:
Object show all
Includes:
ResponseHelpers
Defined in:
lib/cloudkit/store.rb

Overview

A functional storage interface with HTTP semantics and pluggable adapters.

Instance Method Summary collapse

Methods included from ResponseHelpers

#allow, #data_required, #etag_required, #internal_server_error, #invalid_entity_type, #json_error, #json_error_response, #json_meta_response, #response, #status_404, #status_405, #status_410, #status_412, #status_422

Constructor Details

#initialize(options) ⇒ Store

Initialize a new Store, creating its schema if needed. All resources in a Store are automatically versioned.

Options

  • :adapter - Optional. An instance of Adapter. Defaults to in-memory SQLite.

  • :collections - Array of resource collections to manage.

  • :views - Optional. Array of views to be updated based on JSON content.

Example

store = CloudKit::Store.new(:collections => [:foos, :bars])

Example

adapter = CloudKit::SQLAdapter.new('mysql://user:pass@localhost/my_db')
fruit_color_view = CloudKit::ExtractionView.new(
  :fruits_by_color_and_season,
  :observe => :fruits,
  :extract => [:color, :season])
store = CloudKit::Store.new(
  :adapter     => adapter,
  :collections => [:foos, :fruits],
  :views       => [fruit_color_view])

See also: Adapter, ExtractionView, Response



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# File 'lib/cloudkit/store.rb', line 31

def initialize(options)
  @db          = options[:adapter] || SQLAdapter.new
  @collections = options[:collections]
  @views       = options[:views]
  @views.each {|view| view.initialize_storage(@db)} if @views
end

Instance Method Details

#collection_type(uri) ⇒ Object

Return the resource collection referenced by a URI. Example: collection_type(‘/foos/123’) => :foos



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# File 'lib/cloudkit/store.rb', line 232

def collection_type(uri)
  uri_components(uri)[0].to_sym rescue nil
end

#collection_uri_fragment(uri) ⇒ Object

Return the resource collection URI fragment. Example: collection_uri_fragment(‘/foos/123’) => ‘/foos



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# File 'lib/cloudkit/store.rb', line 226

def collection_uri_fragment(uri)
  "/#{uri_components(uri)[0]}" rescue nil
end

#current_resource_uri(uri) ⇒ Object

Return the URI for the current version of a resource. Example: current_resource_uri(‘/foos/123/versions/abc’) => ‘/foos/123’



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# File 'lib/cloudkit/store.rb', line 238

def current_resource_uri(uri)
  "/#{uri_components(uri)[0..1].join('/')}" rescue nil
end

#delete(uri, options = {}) ⇒ Object

Delete the resource specified by the URI. Requires the :etag option.



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# File 'lib/cloudkit/store.rb', line 132

def delete(uri, options={})
  methods = methods_for_uri(uri)
  return status_405(methods) unless methods.include?('DELETE')
  return invalid_entity_type unless @collections.include?(collection_type(uri))
  return etag_required       unless options[:etag]
  original = @db[CLOUDKIT_STORE].
    filter(options.excluding(:etag).merge(:uri => uri))
  if original.any?
    item = original.first
    return status_404 unless item[:remote_user] == options[:remote_user]
    return status_410 if item[:deleted]
    return status_412 if item[:etag] != options[:etag]
    version_uri = ''
    @db.transaction do
      version_uri = "#{item[:uri]}/versions/#{item[:etag]}"
      original.update(:uri => version_uri)
      @db[CLOUDKIT_STORE].insert(
        :uri                  => item[:uri],
        :collection_reference => item[:collection_reference],
        :resource_reference   => item[:resource_reference],
        :remote_user          => item[:remote_user],
        :content              => item[:content],
        :deleted              => true)
      unmap(uri)
    end
    return json_meta_response(200, version_uri, item[:etag], item[:last_modified])
  end
  status_404
end

#get(uri, options = {}) ⇒ Object

Retrieve a resource or collection of resources based on a URI.

Parameters

  • uri - URI of the resource or collection to retrieve.

  • options - See below.

Options

  • :remote_user - Optional. Scopes the dataset if provided.

  • :limit - Optional. Default is unlimited. Limit the number of records returned by a collection request.

  • :offset - Optional. Start the list of resources in a collection at offset (0-based).

  • :any - Optional. Not a literal “:any”, but any key or keys defined as extrations from a view.

URI Types

/cloudkit-meta
/{collection}
/{collection}/_resolved
/{collection}/{uuid}
/{collection}/{uuid}/versions
/{collection}/{uuid}/versions/_resolved
/{collection}/{uuid}/versions/{etag}
/{view}

Examples

get('/cloudkit-meta')
get('/foos')
get('/foos', :remote_user => 'coltrane')
get('/foos', :limit => 100, :offset => 200)
get('/foos/123')
get('/foos/123/versions')
get('/foos/123/versions/abc')
get('/shiny_foos', :color => 'green')

See also: REST API



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# File 'lib/cloudkit/store.rb', line 72

def get(uri, options={})
  return invalid_entity_type                        if !valid_collection_type?(collection_type(uri))
  return meta                                       if meta_uri?(uri)
  return resource_collection(uri, options)          if resource_collection_uri?(uri)
  return resolved_resource_collection(uri, options) if resolved_resource_collection_uri?(uri)
  return resource(uri, options)                     if resource_uri?(uri)
  return version_collection(uri, options)           if version_collection_uri?(uri)
  return resolved_version_collection(uri, options)  if resolved_version_collection_uri?(uri)
  return resource_version(uri, options)             if resource_version_uri?(uri)
  return view(uri, options)                         if view_uri?(uri)
  status_404
end

#head(uri, options = {}) ⇒ Object

Retrieve the same items as the get method, minus the content/body. Using this method on a single resource URI performs a slight optimization due to the way CloudKit stores its ETags and Last-Modified information on write.



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# File 'lib/cloudkit/store.rb', line 89

def head(uri, options={})
  return invalid_entity_type unless @collections.include?(collection_type(uri))
  if resource_uri?(uri) || resource_version_uri?(uri)
    # ETag and Last-Modified are already stored for single items, so a slight
    # optimization can be made for HEAD requests.
    result = @db[CLOUDKIT_STORE].
      select(:etag, :last_modified, :deleted).
      filter(options.merge(:uri => uri))
    if result.any?
      result = result.first
      return status_410.head if result[:deleted]
      return response(200, '', result[:etag], result[:last_modified])
    end
    status_404.head
  else
    get(uri, options).head
  end
end

#http_methods ⇒ Object

Return the list of HTTP methods supported by this Store.



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# File 'lib/cloudkit/store.rb', line 220

def http_methods
  ['GET', 'HEAD', 'POST', 'PUT', 'DELETE', 'OPTIONS']
end

#implements?(http_method) ⇒ Boolean

Return true if this store implements a given HTTP method.

Returns:

  • (Boolean) 


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# File 'lib/cloudkit/store.rb', line 215

def implements?(http_method)
  http_methods.include?(http_method.upcase)
end

#meta_methods ⇒ Object

Return the list of methods allowed for the cloudkit-meta URI.



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# File 'lib/cloudkit/store.rb', line 180

def meta_methods
  @meta_methods ||= http_methods.excluding('POST', 'PUT', 'DELETE')
end

#meta_uri?(uri) ⇒ Boolean

Returns true if URI matches /cloudkit-meta

Returns:

  • (Boolean) 


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# File 'lib/cloudkit/store.rb', line 248

def meta_uri?(uri)
  c = uri_components(uri)
  return c.size == 1 && c[0] == 'cloudkit-meta'
end

#methods_for_uri(uri) ⇒ Object

Return a list of allowed methods for a given URI.



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# File 'lib/cloudkit/store.rb', line 169

def methods_for_uri(uri)
  return meta_methods                         if meta_uri?(uri)
  return resource_collection_methods          if resource_collection_uri?(uri)
  return resolved_resource_collection_methods if resolved_resource_collection_uri?(uri)
  return resource_methods                     if resource_uri?(uri)
  return version_collection_methods           if version_collection_uri?(uri)
  return resolved_version_collection_methods  if resolved_version_collection_uri?(uri)
  return resource_version_methods             if resource_version_uri?(uri)
end

#options(uri) ⇒ Object

Build a response containing the allowed methods for a given URI.



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# File 'lib/cloudkit/store.rb', line 163

def options(uri)
  methods = methods_for_uri(uri)
  allow(methods)
end

#post(uri, options = {}) ⇒ Object

Create a resource in a given collection.



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# File 'lib/cloudkit/store.rb', line 122

def post(uri, options={})
  methods = methods_for_uri(uri)
  return status_405(methods) unless methods.include?('POST')
  return invalid_entity_type unless @collections.include?(collection_type(uri))
  return data_required       unless options[:json]
  uri = "#{collection_uri_fragment(uri)}/#{UUID.generate}"
  create_resource(uri, options)
end

#put(uri, options = {}) ⇒ Object

Update or create a resource at the specified URI. If the resource already exists, an :etag option is required.



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# File 'lib/cloudkit/store.rb', line 110

def put(uri, options={})
  methods = methods_for_uri(uri)
  return status_405(methods) unless methods.include?('PUT')
  return invalid_entity_type unless @collections.include?(collection_type(uri))
  return data_required       unless options[:json]
  current_resource = resource(uri, options.excluding(:json, :etag, :remote_user))
  return update_resource(uri, options) if current_resource.status == 200
  return current_resource if current_resource.status == 410
  create_resource(uri, options)
end

#reset! ⇒ Object

Clear all contents of the store. Used mostly for testing.



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# File 'lib/cloudkit/store.rb', line 305

def reset!
  @db.schema.keys.each do |table|
    @db[table.gsub('`','').to_sym].delete
  end
end

#resolve_uris(uris) ⇒ Object

Return an array containing the response for each URI in a list.



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# File 'lib/cloudkit/store.rb', line 296

def resolve_uris(uris)
  result = []
  uris.each do |uri|
    result << get(uri)
  end
  result
end

#resolved_resource_collection_methods ⇒ Object

Return the list of methods allowed on a resolved resource collection.



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# File 'lib/cloudkit/store.rb', line 190

def resolved_resource_collection_methods
  @resolved_resource_collection_methods ||= http_methods.excluding('POST', 'PUT', 'DELETE')
end

#resolved_resource_collection_uri?(uri) ⇒ Boolean

Returns true if URI matches /collection/_resolved

Returns:

  • (Boolean) 


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# File 'lib/cloudkit/store.rb', line 260

def resolved_resource_collection_uri?(uri)
  c = uri_components(uri)
  return c.size == 2 && @collections.include?(c[0].to_sym) && c[1] == '_resolved'
end

#resolved_version_collection_methods ⇒ Object

Return the list of methods allowed on a resolved version history collection.



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# File 'lib/cloudkit/store.rb', line 205

def resolved_version_collection_methods
  @resolved_version_collection_methods ||= http_methods.excluding('POST', 'PUT', 'DELETE')
end

#resolved_version_collection_uri?(uri) ⇒ Boolean

Returns true if URI matches /collection/uuid/versions/_resolved

Returns:

  • (Boolean) 


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# File 'lib/cloudkit/store.rb', line 278

def resolved_version_collection_uri?(uri)
  c = uri_components(uri)
  return c.size == 4 && @collections.include?(c[0].to_sym) && c[2] == 'versions' && c[3] == '_resolved'
end

#resource_collection_methods ⇒ Object

Return the list of methods allowed for a resource collection.



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# File 'lib/cloudkit/store.rb', line 185

def resource_collection_methods
  @resource_collection_methods ||= http_methods.excluding('PUT', 'DELETE')
end

#resource_collection_uri?(uri) ⇒ Boolean

Returns true if URI matches /collection

Returns:

  • (Boolean) 


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# File 'lib/cloudkit/store.rb', line 254

def resource_collection_uri?(uri)
  c = uri_components(uri)
  return c.size == 1 && @collections.include?(c[0].to_sym)
end

#resource_methods ⇒ Object

Return the list of methods allowed on an individual resource.



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# File 'lib/cloudkit/store.rb', line 195

def resource_methods
  @resource_methods ||= http_methods.excluding('POST')
end

#resource_uri?(uri) ⇒ Boolean

Returns true if URI matches /collection/uuid

Returns:

  • (Boolean) 


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# File 'lib/cloudkit/store.rb', line 266

def resource_uri?(uri)
  c = uri_components(uri)
  return c.size == 2 && @collections.include?(c[0].to_sym) && c[1] != '_resolved'
end

#resource_version_methods ⇒ Object

Return the list of methods allowed on a resource version.



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# File 'lib/cloudkit/store.rb', line 210

def resource_version_methods
  @resource_version_methods ||= http_methods.excluding('POST', 'PUT', 'DELETE')
end

#resource_version_uri?(uri) ⇒ Boolean

Returns true if URI matches /collection/uuid/versions/etag

Returns:

  • (Boolean) 


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# File 'lib/cloudkit/store.rb', line 284

def resource_version_uri?(uri)
  c = uri_components(uri)
  return c.size == 4 && @collections.include?(c[0].to_sym) && c[2] == 'versions' && c[3] != '_resolved'
end

#uri_components(uri) ⇒ Object

Splits a URI into its components



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# File 'lib/cloudkit/store.rb', line 243

def uri_components(uri)
  uri.split('/').reject{|x| x == '' || x == nil} rescue []
end

#version ⇒ Object

Return the version number of this Store.



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# File 'lib/cloudkit/store.rb', line 312

def version; 1; end

#version_collection_methods ⇒ Object

Return the list of methods allowed on a version history collection.



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# File 'lib/cloudkit/store.rb', line 200

def version_collection_methods
  @version_collection_methods ||= http_methods.excluding('POST', 'PUT', 'DELETE')
end

#version_collection_uri?(uri) ⇒ Boolean

Returns true if URI matches /collection/uuid/versions

Returns:

  • (Boolean) 


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# File 'lib/cloudkit/store.rb', line 272

def version_collection_uri?(uri)
  c = uri_components(uri)
  return c.size == 3 && @collections.include?(c[0].to_sym) && c[2] == 'versions'
end

#view_uri?(uri) ⇒ Boolean

Returns true if URI matches /#view

Returns:

  • (Boolean) 


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# File 'lib/cloudkit/store.rb', line 290

def view_uri?(uri)
  c = uri_components(uri)
  return c.size == 1 && @views && @views.map{|v| v.name}.include?(c[0].to_sym)
end