From 04709222758e199c8c77654326dc2c97a91e82f9 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Tue, 24 May 2022 16:41:30 +0100
Subject: [PATCH] add extended targetcustom support
but TIFF write fails for some reason argh
---
example/connection.rb | 32 +++++++++++++-----
lib/vips/image.rb | 8 +++--
lib/vips/object.rb | 8 +++++
lib/vips/targetcustom.rb | 57 ++++++++++++++++++++++++++++++-
spec/connection_spec.rb | 73 +++++++++++++++++++++++++++-------------
5 files changed, 144 insertions(+), 34 deletions(-)
diff --git a/example/connection.rb b/example/connection.rb
index 1a9c45cf..129ee4aa 100755
--- a/example/connection.rb
+++ b/example/connection.rb
@@ -1,26 +1,42 @@
#!/usr/bin/ruby
require "vips"
-require "down/http"
+# gem install down
+require "down"
# byte_source = File.open ARGV[0], "rb"
# eg. https://images.unsplash.com/photo-1491933382434-500287f9b54b
-byte_source = Down::Http.open(ARGV[0])
+byte_source = Down::open(ARGV[0])
source = Vips::SourceCustom.new
source.on_read do |length|
- puts "reading #{length} bytes ..."
+ puts "source: reading #{length} bytes ..."
byte_source.read length
end
source.on_seek do |offset, whence|
- puts "seeking to #{offset}, #{whence}"
+ puts "source: seeking to #{offset}, #{whence}"
byte_source.seek(offset, whence)
end
-byte_target = File.open ARGV[1], "wb"
+byte_target = File.open ARGV[1], "w+b"
+
target = Vips::TargetCustom.new
-target.on_write { |chunk| byte_target.write(chunk) }
-target.on_finish { byte_target.close }
+target.on_write do |chunk|
+ puts "target: writing #{chunk.length} bytes ..."
+ byte_target.write(chunk)
+end
+target.on_read do |length|
+ puts "target: reading #{length} bytes ..."
+ byte_target.read length
+end
+target.on_seek do |offset, whence|
+ puts "target: seeking to #{offset}, #{whence}"
+ byte_target.seek(offset, whence)
+end
+target.on_end do
+ puts "target: ending"
+ byte_target.close
+end
image = Vips::Image.new_from_source source, "", access: :sequential
-image.write_to_target target, ".jpg"
+image.write_to_target target, ARGV[2]
diff --git a/lib/vips/image.rb b/lib/vips/image.rb
index bae9c372..03d63e62 100644
--- a/lib/vips/image.rb
+++ b/lib/vips/image.rb
@@ -548,8 +548,12 @@ def self.new_from_array array, scale = 1, offset = 0
def new_from_image value
pixel = (Vips::Image.black(1, 1) + value).cast(format)
image = pixel.embed 0, 0, width, height, extend: :copy
- image.copy interpretation: interpretation, xres: xres, yres: yres,
- xoffset: xoffset, yoffset: yoffset
+ image.copy \
+ interpretation: interpretation,
+ xres: xres,
+ yres: yres,
+ xoffset: xoffset,
+ yoffset: yoffset
end
# Write this image to a file. Save options may be encoded in the
diff --git a/lib/vips/object.rb b/lib/vips/object.rb
index 3b3e92de..860892c9 100644
--- a/lib/vips/object.rb
+++ b/lib/vips/object.rb
@@ -108,6 +108,13 @@ class Progress < FFI::Struct
end
end
+ MARSHAL_END = proc do |handler|
+ FFI::Function.new(:int, [:pointer, :pointer]) do |i, cb|
+ # this can't throw an exception, so no catch is necessary
+ handler.call
+ end
+ end
+
MARSHAL_FINISH = proc do |handler|
FFI::Function.new(:void, [:pointer, :pointer]) do |i, cb|
# this can't throw an exception, so no catch is necessary
@@ -123,6 +130,7 @@ class Progress < FFI::Struct
read: MARSHAL_READ,
seek: MARSHAL_SEEK,
write: MARSHAL_WRITE,
+ end: MARSHAL_END,
finish: MARSHAL_FINISH
}
diff --git a/lib/vips/targetcustom.rb b/lib/vips/targetcustom.rb
index 9f07db75..4372f365 100644
--- a/lib/vips/targetcustom.rb
+++ b/lib/vips/targetcustom.rb
@@ -66,8 +66,63 @@ def on_write &block
end
end
+ # The block is executed to read data from the target. The interface is
+ # exactly as IO::read, ie. it takes a maximum number of bytes to read and
+ # returns a string of bytes from the target, or nil if the target is already
+ # at end of file.
+ #
+ # This handler is optional and only needed for image formats which have
+ # to be able to read their own output, like TIFF.
+ #
+ # @yieldparam length [Integer] Read and return up to this many bytes
+ # @yieldreturn [String] Up to length bytes of data, or nil for EOF
+ def on_read &block
+ # target read added in 8.13
+ if Vips.at_least_libvips?(8, 13)
+ signal_connect "read" do |buf, len|
+ chunk = block.call len
+ return 0 if chunk.nil?
+ bytes_read = chunk.bytesize
+ buf.put_bytes(0, chunk, 0, bytes_read)
+ chunk.clear
+
+ bytes_read
+ end
+ end
+ end
+
+ # The block is executed to seek the target. The interface is exactly as
+ # IO::seek, ie. it should take an offset and whence, and return the
+ # new read position.
+ #
+ # This handler is optional and only needed for image formats which have
+ # to be able to read their own output, like TIFF.
+ #
+ # @yieldparam offset [Integer] Seek offset
+ # @yieldparam whence [Integer] Seek whence
+ # @yieldreturn [Integer] the new read position, or -1 on error
+ def on_seek &block
+ # target seek added in 8.13
+ if Vips.at_least_libvips?(8, 13)
+ signal_connect "seek" do |offset, whence|
+ block.call offset, whence
+ end
+ end
+ end
+
# The block is executed at the end of write. It should do any necessary
- # finishing action, such as closing a file.
+ # finishing action, such as closing a file, and return 0 on sucess and -1
+ # on error
+ #
+ # @yieldreturn [Integer] 0 on sucess, or -1 on error
+ def on_end &block
+ signal_name = Vips.at_least_libvips?(8, 13) ? "end" : "finish"
+ signal_connect signal_name do
+ block.call
+ end
+ end
+
+ # Deprecated name for libvips before 8.13
def on_finish &block
signal_connect "finish" do
block.call
diff --git a/spec/connection_spec.rb b/spec/connection_spec.rb
index 6c4ee0df..33bc1d2d 100644
--- a/spec/connection_spec.rb
+++ b/spec/connection_spec.rb
@@ -36,12 +36,13 @@
it "can load an image from filename source" do
source = Vips::Source.new_from_file simg("wagon.jpg")
image = Vips::Image.new_from_source source, ""
+ real = Vips::Image.new_from_file simg("wagon.jpg")
expect(image)
- expect(image.width).to eq(685)
- expect(image.height).to eq(478)
- expect(image.bands).to eq(3)
- expect(image.avg).to be_within(0.001).of(109.789)
+ expect(image.width).to eq(real.width)
+ expect(image.height).to eq(real.height)
+ expect(image.bands).to eq(real.bands)
+ expect(image.avg).to eq(real.avg)
end
end
@@ -76,13 +77,14 @@
filename = timg("x4.png")
target = Vips::Target.new_to_file filename
image.write_to_target target, ".png"
+ real = Vips::Image.new_from_file simg("wagon.jpg")
image = Vips::Image.new_from_file filename
expect(image)
- expect(image.width).to eq(685)
- expect(image.height).to eq(478)
- expect(image.bands).to eq(3)
- expect(image.avg).to be_within(0.001).of(109.789)
+ expect(image.width).to eq(real.width)
+ expect(image.height).to eq(real.height)
+ expect(image.bands).to eq(real.bands)
+ expect(image.avg).to eq(real.avg)
end
it "can save an image to a memory target" do
@@ -114,12 +116,13 @@
source.on_read { |length| file.read length }
source.on_seek { |offset, whence| file.seek(offset, whence) }
image = Vips::Image.new_from_source source, ""
+ real = Vips::Image.new_from_file simg("wagon.jpg")
expect(image)
- expect(image.width).to eq(685)
- expect(image.height).to eq(478)
- expect(image.bands).to eq(3)
- expect(image.avg).to be_within(0.001).of(109.789)
+ expect(image.width).to eq(real.width)
+ expect(image.height).to eq(real.height)
+ expect(image.bands).to eq(real.bands)
+ expect(image.avg).to eq(real.avg)
end
it "on_seek is optional" do
@@ -127,34 +130,58 @@
source = Vips::SourceCustom.new
source.on_read { |length| file.read length }
image = Vips::Image.new_from_source source, ""
+ real = Vips::Image.new_from_file simg("wagon.jpg")
expect(image)
- expect(image.width).to eq(685)
- expect(image.height).to eq(478)
- expect(image.bands).to eq(3)
- expect(image.avg).to be_within(0.001).of(109.789)
+ expect(image.width).to eq(real.width)
+ expect(image.height).to eq(real.height)
+ expect(image.bands).to eq(real.bands)
+ expect(image.avg).to eq(real.avg)
end
- it "can create a user output stream" do
+ it "can create a custom target" do
target = Vips::TargetCustom.new
expect(target)
end
- it "can write an image to a user output stream" do
+ it "can write an image to a custom target" do
filename = timg("x5.png")
file = File.open filename, "wb"
target = Vips::TargetCustom.new
target.on_write { |chunk| file.write(chunk) }
- target.on_finish { file.close }
+ target.on_end { file.close }
image = Vips::Image.new_from_file simg("wagon.jpg")
image.write_to_target target, ".png"
image = Vips::Image.new_from_file filename
+ real = Vips::Image.new_from_file simg("wagon.jpg")
expect(image)
- expect(image.width).to eq(685)
- expect(image.height).to eq(478)
- expect(image.bands).to eq(3)
- expect(image.avg).to be_within(0.001).of(109.789)
+ expect(image.width).to eq(real.width)
+ expect(image.height).to eq(real.height)
+ expect(image.bands).to eq(real.bands)
+ expect(image.avg).to eq(real.avg)
+ end
+end
+
+RSpec.describe Vips::TargetCustom, version: [8, 13] do
+ it "can write to a custom target as TIFF" do
+ filename = timg("x6.tif")
+ file = File.open filename, "w+b"
+ target = Vips::TargetCustom.new
+ target.on_write { |chunk| file.write(chunk) }
+ target.on_read { |length| file.read length }
+ target.on_seek { |offset, whence| file.seek(offset, whence) }
+ target.on_end { file.close; 0 }
+ image = Vips::Image.new_from_file simg("wagon.jpg")
+ image.write_to_target target, ".tif"
+
+ image = Vips::Image.new_from_file filename
+ real = Vips::Image.new_from_file simg("wagon.jpg")
+ expect(image)
+ expect(image.width).to eq(real.width)
+ expect(image.height).to eq(real.height)
+ expect(image.bands).to eq(real.bands)
+ expect(image.avg).to eq(real.avg)
end
end