Class: LargeObjectStore::RailsWrapper
- Inherits:
-
Object
- Object
- LargeObjectStore::RailsWrapper
- Defined in:
- lib/large_object_store.rb
Instance Attribute Summary collapse
-
#store ⇒ Object
readonly
Returns the value of attribute store.
Instance Method Summary collapse
- #delete(key) ⇒ Object
- #fetch(key, options = {}) ⇒ Object
-
#initialize(store) ⇒ RailsWrapper
constructor
A new instance of RailsWrapper.
- #read(key) ⇒ Object
- #write(key, value, options = {}) ⇒ Object
Constructor Details
#initialize(store) ⇒ RailsWrapper
Returns a new instance of RailsWrapper.
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# File 'lib/large_object_store.rb', line 24 def initialize(store) @store = store end |
Instance Attribute Details
#store ⇒ Object (readonly)
Returns the value of attribute store.
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# File 'lib/large_object_store.rb', line 22 def store @store end |
Instance Method Details
#delete(key) ⇒ Object
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# File 'lib/large_object_store.rb', line 87 def delete(key) @store.delete(key(key, 0)) end |
#fetch(key, options = {}) ⇒ Object
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# File 'lib/large_object_store.rb', line 79 def fetch(key, ={}) value = read(key) return value unless value.nil? value = yield write(key, value, ) value end |
#read(key) ⇒ Object
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# File 'lib/large_object_store.rb', line 59 def read(key) # read pages pages, uuid = @store.read(key(key, 0)) return if pages.nil? data = if pages.is_a?(Fixnum) # read sliced data keys = Array.new(pages).each_with_index.map{|_,i| key(key, i+1) } slices = @store.read_multi(*keys).values return nil if slices.compact.size != pages slices.map! { |s| [s.slice!(0, UUID_SIZE), s] } return nil unless slices.map(&:first).uniq == [uuid] slices.map!(&:last).join("") else pages end deserialize(data) end |
#write(key, value, options = {}) ⇒ Object
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# File 'lib/large_object_store.rb', line 28 def write(key, value, = {}) = .dup value = serialize(value, ) # calculate slice size; note that key length is a factor because # the key is stored on the same slab page as the value slice_size = MAX_OBJECT_SIZE - ITEM_HEADER_SIZE - UUID_SIZE - key.bytesize # store number of pages pages = (value.size / slice_size.to_f).ceil if pages == 1 !!@store.write(key(key, 0), value, ) else # store meta uuid = SecureRandom.hex(UUID_BYTES) return false unless @store.write(key(key, 0), [pages, uuid], ) # invalidates the old cache # store object page = 1 loop do slice = value.slice!(0, slice_size) break if slice.size == 0 return false unless @store.write(key(key, page), slice.prepend(uuid), .merge(raw: true)) page += 1 end true end end |