implementing script metadata and DAG sorting mechanism

modules/extensions.py

@@ -1,3 +1,5 @@
+import configparser
+import functools
 import os
 import threading
 
@@ -23,8 +25,9 @@ class Extension:
     lock = threading.Lock()
     cached_fields = ['remote', 'commit_date', 'branch', 'commit_hash', 'version']
 
-    def __init__(self, name, path, enabled=True, is_builtin=False):
+    def __init__(self, name, path, enabled=True, is_builtin=False, canonical_name=None):
         self.name = name
+        self.canonical_name = canonical_name or name.lower()
         self.path = path
         self.enabled = enabled
         self.status = ''
@@ -37,6 +40,17 @@ class Extension:
         self.remote = None
         self.have_info_from_repo = False
 
+    @functools.cached_property
+    def metadata(self):
+        if os.path.isfile(os.path.join(self.path, "sd_webui_metadata.ini")):
+            try:
+                config = configparser.ConfigParser()
+                config.read(os.path.join(self.path, "sd_webui_metadata.ini"))
+                return config
+            except Exception:
+                errors.report(f"Error reading sd_webui_metadata.ini for extension {self.canonical_name}.", exc_info=True)
+        return None
+
     def to_dict(self):
         return {x: getattr(self, x) for x in self.cached_fields}
 
@@ -136,9 +150,6 @@ class Extension:
 def list_extensions():
     extensions.clear()
 
-    if not os.path.isdir(extensions_dir):
-        return
-
     if shared.cmd_opts.disable_all_extensions:
         print("*** \"--disable-all-extensions\" arg was used, will not load any extensions ***")
     elif shared.opts.disable_all_extensions == "all":
@@ -148,18 +159,69 @@ def list_extensions():
     elif shared.opts.disable_all_extensions == "extra":
         print("*** \"Disable all extensions\" option was set, will only load built-in extensions ***")
 
-    extension_paths = []
+    extension_dependency_map = {}
+
+    # scan through extensions directory and load metadata
     for dirname in [extensions_dir, extensions_builtin_dir]:
         if not os.path.isdir(dirname):
-            return
+            continue
 
         for extension_dirname in sorted(os.listdir(dirname)):
             path = os.path.join(dirname, extension_dirname)
             if not os.path.isdir(path):
                 continue
 
-            extension_paths.append((extension_dirname, path, dirname == extensions_builtin_dir))
+            canonical_name = extension_dirname
+            requires = None
 
-    for dirname, path, is_builtin in extension_paths:
-        extension = Extension(name=dirname, path=path, enabled=dirname not in shared.opts.disabled_extensions, is_builtin=is_builtin)
+            if os.path.isfile(os.path.join(path, "sd_webui_metadata.ini")):
+                try:
+                    config = configparser.ConfigParser()
+                    config.read(os.path.join(path, "sd_webui_metadata.ini"))
+                    canonical_name = config.get("Extension", "Name", fallback=canonical_name)
+                    requires = config.get("Extension", "Requires", fallback=None)
+                    continue
+                except Exception:
+                    errors.report(f"Error reading sd_webui_metadata.ini for extension {extension_dirname}. "
+                                  f"Will load regardless.", exc_info=True)
+
+            canonical_name = canonical_name.lower().strip()
+
+            # check for duplicated canonical names
+            if canonical_name in extension_dependency_map:
+                errors.report(f"Duplicate canonical name \"{canonical_name}\" found in extensions "
+                              f"\"{extension_dirname}\" and \"{extension_dependency_map[canonical_name]['dirname']}\". "
+                              f"The current loading extension will be discarded.", exc_info=False)
+                continue
+
+            # we want to wash the data to lowercase and remove whitespaces just in case
+            requires = [x.strip() for x in requires.lower().split(',')] if requires else []
+
+            extension_dependency_map[canonical_name] = {
+                "dirname": extension_dirname,
+                "path": path,
+                "requires": requires,
+            }
+
+    # check for requirements
+    for (_, extension_data) in extension_dependency_map.items():
+        dirname, path, requires = extension_data['dirname'], extension_data['path'], extension_data['requires']
+        requirement_met = True
+        for req in requires:
+            if req not in extension_dependency_map:
+                errors.report(f"Extension \"{dirname}\" requires \"{req}\" which is not installed. "
+                              f"The current loading extension will be discarded.", exc_info=False)
+                requirement_met = False
+                break
+            dep_dirname = extension_dependency_map[req]['dirname']
+            if dep_dirname in shared.opts.disabled_extensions:
+                errors.report(f"Extension \"{dirname}\" requires \"{dep_dirname}\" which is disabled. "
+                              f"The current loading extension will be discarded.", exc_info=False)
+                requirement_met = False
+                break
+
+        is_builtin = dirname == extensions_builtin_dir
+        extension = Extension(name=dirname, path=path,
+                              enabled=dirname not in shared.opts.disabled_extensions and requirement_met,
+                              is_builtin=is_builtin)
         extensions.append(extension)