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# This module provides an interface to the top level bits of libvips
# via ruby-ffi.
#
# Author:: John Cupitt (mailto:jcupitt@gmail.com)
# License:: MIT
require "ffi"
module Vips
if Vips.at_least_libvips?(8, 9)
attach_function :vips_source_new_from_descriptor, [:int], :pointer
attach_function :vips_source_new_from_file, [:pointer], :pointer
attach_function :vips_source_new_from_memory, [:pointer, :size_t], :pointer
end
# A source. For example:
#
# ```ruby
# source = Vips::Source.new_from_file("k2.jpg")
# image = Vips::Image.new_from_source(source)
# ```
class Source < Vips::Connection
module SourceLayout
def self.included(base)
base.class_eval do
layout :parent, Vips::Connection::Struct
# rest opaque
end
end
end
class Struct < Vips::Connection::Struct
include SourceLayout
end
class ManagedStruct < Vips::Connection::ManagedStruct
include SourceLayout
end
# Create a new source from a file descriptor. File descriptors are
# small integers, for example 0 is stdin.
#
# Pass sources to {Image.new_from_source} to load images from
# them.
#
# @param descriptor [Integer] the file descriptor
# @return [Source] the new Vips::Source
def self.new_from_descriptor(descriptor)
ptr = Vips.vips_source_new_from_descriptor descriptor
raise Vips::Error if ptr.null?
Vips::Source.new ptr
end
# Create a new source from a file name.
#
# Pass sources to {Image.new_from_source} to load images from
# them.
#
# @param filename [String] the name of the file
# @return [Source] the new Vips::Source
def self.new_from_file(filename)
raise Vips::Error, "filename is nil" if filename.nil?
ptr = Vips.vips_source_new_from_file filename
raise Vips::Error if ptr.null?
Vips::Source.new ptr
end
# Create a new source from an area of memory. Memory areas can be
# strings, arrays and so forth -- anything that supports bytesize.
#
# Pass sources to {Image.new_from_source} to load images from
# them.
#
# @param data [String] memory area
# @return [Source] the new Vips::Source
def self.new_from_memory(data)
ptr = Vips.vips_source_new_from_memory data, data.bytesize
raise Vips::Error if ptr.null?
# FIXME do we need to keep a ref to the underlying memory area? what
# about Image.new_from_buffer? Does that need a secret ref too?
Vips::Source.new ptr
end
end
end
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