From e8d7f1843d56fb93c9db22772e6c9bbd733fd1ea Mon Sep 17 00:00:00 2001
From: dabutvin <butvinik@outlook.com>
Date: Sun, 10 May 2020 13:17:09 -0700
Subject: [PATCH] add gifsicle compression

---
 CompressImagesFunction/CompressImages.cs      |  1 +
 .../Compressors/GifsicleCompress.cs           | 50 +++++++++++++++++++
 Dockerfile.CompressImages                     |  6 +++
 3 files changed, 57 insertions(+)
 create mode 100644 CompressImagesFunction/Compressors/GifsicleCompress.cs

diff --git a/CompressImagesFunction/CompressImages.cs b/CompressImagesFunction/CompressImages.cs
index b17eda88b..20e09240e 100644
--- a/CompressImagesFunction/CompressImages.cs
+++ b/CompressImagesFunction/CompressImages.cs
@@ -23,6 +23,7 @@ public static class CompressImages
             new ImageMagickCompress(),
             new SvgoCompress(),
             new MozJpegCompress(),
+            new GifsicleCompress(),
         };
 
         public static bool Run(CompressimagesParameters parameters, ICollector<CompressImagesMessage> compressImagesMessages, ILogger logger)
diff --git a/CompressImagesFunction/Compressors/GifsicleCompress.cs b/CompressImagesFunction/Compressors/GifsicleCompress.cs
new file mode 100644
index 000000000..e3af7559d
--- /dev/null
+++ b/CompressImagesFunction/Compressors/GifsicleCompress.cs
@@ -0,0 +1,50 @@
+using System.Diagnostics;
+
+namespace CompressImagesFunction.Compressors
+{
+    /*
+    -O[level]
+    --optimize[=level]
+        Optimize  output GIF animations for space.  Level determines how much optimization is
+        done; higher levels take longer, but may have better  results.  There  are  currently
+        three levels:
+
+        -O1  Stores only the changed portion of each image. This is the default.
+        -O2  Also uses transparency to shrink the file further.
+        -O3  Try several optimization methods (usually slower, sometimes better results).
+
+    To modify GIF files in place, you should use the --batch option.  With  --batch,  gifsicle
+    will modify the files you specify instead of writing a new file to the standard output.
+    */
+    public class GifsicleCompress : ICompress
+    {
+        public string[] SupportedExtensions => new[] { ".gif" };
+
+        public void LosslessCompress(string path)
+        {
+            var arguments = $"-O3 --batch {path}";
+            Compress(arguments);
+        }
+
+        public void LossyCompress(string path)
+        {
+            var arguments = $"-O3 --lossy=80 --batch {path}";
+            Compress(arguments);
+        }
+
+        private void Compress(string arguments)
+        {
+            var processStartInfo = new ProcessStartInfo
+            {
+                UseShellExecute = false,
+                CreateNoWindow = true,
+                FileName = "gifsicle",
+                Arguments = arguments,
+            };
+            using (var process = Process.Start(processStartInfo))
+            {
+                process.WaitForExit(10000);
+            }
+        }
+    }
+}
diff --git a/Dockerfile.CompressImages b/Dockerfile.CompressImages
index c8ae6d15e..d92b90ee2 100644
--- a/Dockerfile.CompressImages
+++ b/Dockerfile.CompressImages
@@ -27,5 +27,11 @@ RUN cd /tmp/mozjpeg-3.3.1/build && sh ../configure && make install
 RUN ln -s /opt/mozjpeg/bin/jpegtran /usr/local/bin/mozjpegtran
 RUN ln -s /opt/mozjpeg/bin/cjpeg /usr/local/bin/mozcjpeg
 
+# Add support for gifsicle
+RUN cd /tmp && wget https://github.com/kohler/gifsicle/archive/v1.92.tar.gz
+RUN cd /tmp && tar -xzf v1.92.tar.gz
+RUN cd /tmp/gifsicle-1.92 && autoreconf -fiv
+RUN cd /tmp/gifsicle-1.92 && sh ./configure --disable-gifview && make install
+
 ENV AzureWebJobsScriptRoot=/home/site/wwwroot
 COPY --from=dotnet ["/home/site/wwwroot", "/home/site/wwwroot"]