installer: Start work on the installer.

The installer is a tool that will provided primitives for
installing loosely-coupled components (like editors) into
Ren'Py, and eventually, into games.

For now, this implements a download primitive.

launcher/game/installer.py

@@ -0,0 +1,155 @@
+# Copyright 2004-2022 Tom Rothamel <pytom@bishoujo.us>
+#
+# Permission is hereby granted, free of charge, to any person
+# obtaining a copy of this software and associated documentation files
+# (the "Software"), to deal in the Software without restriction,
+# including without limitation the rights to use, copy, modify, merge,
+# publish, distribute, sublicense, and/or sell copies of the Software,
+# and to permit persons to whom the Software is furnished to do so,
+# subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+import hashlib
+import os
+import time
+import requests
+
+from store import _, config, interface # type: ignore
+
+
+
+def temp(filename):
+    """
+    Converts filename into a path inside the temporary directory, creating
+    the extension temporary directory if necessary.
+    """
+
+    rv = os.path.join(config.renpy_base, "tmp", "extension", filename)
+
+    try:
+        os.makedirs(os.path.dirname(rv))
+    except Exception:
+        pass
+
+    return rv
+
+
+# The target directory that the extensions API operates on.
+target = None
+
+
+def set_target(directory):
+    """
+    This sets the directory that the extension API targets. This is where
+    packages are unpacked to and the default working directory where the
+    programs are run.
+    """
+
+    target = directory
+
+
+def path(filename):
+    """
+    Returns a path to the filename inside the target directory.
+    """
+
+    if target is None:
+        raise Exception("The target directory has not been set.")
+
+    return os.path.join(target, filename)
+
+
+def check_hash(filename, hashj):
+    """
+    Returns a cryptographic hash of `filename`. `filename` should
+    be a full path, one returned by temp or path.
+    """
+
+
+    try:
+
+        sha = hashlib.sha256()
+
+        with open(filename, "rb") as f:
+            while True:
+                data = f.read(1024 * 1024)
+                if not data:
+                    break
+
+                sha.update(data)
+
+        return sha.hexdigest() == hash
+
+    except Exception:
+        return False
+
+
+# The name and url of the file that is currently being downloaded. This is meant to
+# to be used by the interface screens to show the user what files are being
+# downloaded.
+download_file = ""
+download_url = ""
+
+def download(url, filename, hash=None):
+    """
+    Downloads `url` to `filename`, a tempfile.
+    """
+    global download_url
+
+    global download_file
+
+    download_url = url
+    download_file = filename
+
+    filename = temp(filename)
+
+    if hash is not None:
+        if check_hash(filename, hash):
+            return
+
+    progress_time = time.time()
+
+    try:
+
+        response = requests.get(url, stream=True)
+        response.raise_for_status()
+
+        total_size = int(response.headers.get('content-length', 1))
+
+        downloaded = 0
+
+        with open(filename, "wb") as f:
+
+            for i in response.iter_content(65536):
+
+                f.write(i)
+                downloaded += len(i)
+
+                if time.time() - progress_time > 0.1:
+                    progress_time = time.time()
+                    interface.processing(
+                        _("Downloading [installer.download_file]."),
+                        complete=downloaded, total=total_size)
+
+    except requests.HTTPError as e:
+        interface.error(_("Could not download [installer.download_file] from [installer.download_url]:\n{b}[installer.download_error]"))
+
+    if hash is not None:
+        if not check_hash(filename, hash):
+            interface.error(_("The downloaded file [installer.download_file] from [installer.download_url] is not correct."))
+
+
+
+def main():
+    set_target("/tmp")
+    download("http://nightly.renpy.org/8-nightly-2022-01-30-50b188065/renpy-8-nightly-2022-01-30-50b188065-sdk.zip", "nightly.zip")

launcher/game/installer.rpy

@@ -0,0 +1,12 @@
+
+# This file imports the extensions API into the default store, and makes it
+# also contains the strings used by the extensions API, so the Ren'Py translation
+# framework can find them.
+
+init python:
+    import installer
+
+init python hide:
+    _("Downloading [extension.download_file].")
+    _("Could not download [extension.download_file] from [extension.download_url]:\n{b}[extension.download_error]")
+    _("The downloaded file [extension.download_file] from [extension.download_url] is not correct.")

scripts/update_installer.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python
+
+import sys
+import os
+import re
+
+import pathlib
+base = pathlib.Path(__file__).absolute().parent.parent
+
+
+def main():
+
+    with open(base / "launcher" / "game" / "installer.rpy", "w") as out:
+        out.write("""
+# This file imports the extensions API into the default store, and makes it
+# also contains the strings used by the extensions API, so the Ren'Py translation
+# framework can find them.
+
+init python:
+    import installer
+
+init python hide:
+""")
+
+        fn = base / "launcher" / "game" / "installer.py"
+
+        with open(fn) as f:
+            data = f.read()
+
+        for m in re.finditer(r'__?\(".*?"\)', data):
+            out.write("    " + m.group(0) + "\n")
+
+
+if __name__ == "__main__":
+    main()