Implement GCodeGzWriter

This plug-in outputs g-code to a gzipped archive. It is used for sending prints to the Ultimaker 3 family faster.

Contributes to issue CURA-5097.

plugins/GCodeGzWriter/GCodeGzWriter.py

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+# Copyright (c) 2018 Ultimaker B.V.
+# Cura is released under the terms of the LGPLv3 or higher.
+
+import gzip
+from io import StringIO, BufferedIOBase #To write the g-code to a temporary buffer, and for typing.
+from typing import List
+
+from UM.Logger import Logger
+from UM.Mesh.MeshWriter import MeshWriter #The class we're extending/implementing.
+from UM.PluginRegistry import PluginRegistry
+from UM.Scene.SceneNode import SceneNode #For typing.
+
+##  A file writer that writes gzipped g-code.
+#
+#   If you're zipping g-code, you might as well use gzip!
+class GCodeGzWriter(MeshWriter):
+    ##  Writes the gzipped g-code to a stream.
+    #
+    #   Note that even though the function accepts a collection of nodes, the
+    #   entire scene is always written to the file since it is not possible to
+    #   separate the g-code for just specific nodes.
+    #
+    #   \param stream The stream to write the gzipped g-code to.
+    #   \param nodes This is ignored.
+    #   \param mode Additional information on what type of stream to use. This
+    #   must always be binary mode.
+    #   \return Whether the write was successful.
+    def write(self, stream: BufferedIOBase, nodes: List[SceneNode], mode = MeshWriter.OutputMode.BinaryMode) -> bool:
+        if mode != MeshWriter.OutputMode.BinaryMode:
+            Logger.log("e", "GCodeGzWriter does not support text mode.")
+            return False
+
+        #Get the g-code from the g-code writer.
+        gcode_textio = StringIO() #We have to convert the g-code into bytes.
+        success = PluginRegistry.getInstance().getPluginObject("GCodeWriter").write(gcode_textio, None)
+        if not success: #Writing the g-code failed. Then I can also not write the gzipped g-code.
+            return False
+
+        result = gzip.compress(gcode_textio.getvalue())
+        stream.write(result)
+        return True

plugins/GCodeGzWriter/__init__.py

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+# Copyright (c) 2018 Ultimaker B.V.
+# Cura is released under the terms of the LGPLv3 or higher.
+
+from . import GCodeGzWriter
+
+from UM.i18n import i18nCatalog
+catalog = i18nCatalog("cura")
+
+def getMetaData():
+    return {
+        "mesh_writer": {
+            "output": [{
+                "extension": "gcode.gz",
+                "description": catalog.i18nc("@item:inlistbox", "Compressed G-code File"),
+                "mime_type": "application/gzip",
+                "mode": GCodeGzWriter.GCodeGzWriter.OutputMode.BinaryMode
+            }]
+        }
+    }
+
+def register(app):
+    return { "mesh_writer": GCodeGzWriter.GCodeGzWriter() }

plugins/GCodeGzWriter/plugin.json

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+{
+    "name": "Compressed G-code Writer",
+    "author": "Ultimaker B.V.",
+    "version": "1.0.0",
+    "description": "Writes g-code to a compressed archive.",
+    "api": 4,
+    "i18n-catalog": "cura"
+}