Add --dry-run option to index command

* bdx/cli.py (index): Add --dry-run option and pass it's value to
`index_binary_directory'.
* bdx/index.py (SymbolIndex.open_shard): Add `readonly' argument that
defaults to False.
(_WorkerPool.__init__): Add `dry_run' argument.
(_WorkerPool._worker): Use it.
(index_binary_directory): Add `dry_run' argument.

Author: mkcms

bdx/cli.py

@@ -327,6 +327,12 @@ def cli():
         " have been modified/removed."
     ),
 )
+@click.option(
+    "-n",
+    "--dry-run",
+    is_flag=True,
+    help="Don't index, instead print out what would be done.",
+)
 def index(
     directory,
     index_path,
@@ -335,9 +341,10 @@ def index(
     reindex,
     exclude,
     delete,
+    dry_run,
 ):
     """Index the specified directory."""
-    if delete:
+    if delete and not dry_run:
         delete_index(index_path)
 
     exclusions = [Exclusion(ex) for ex in exclude]
@@ -352,6 +359,7 @@ def index(
             exclusions=exclusions,
             use_compilation_database=use_compilation_database,
             reindex=reindex,
+            dry_run=dry_run,
         )
     except BinaryDirectory.CompilationDatabaseNotFoundError as e:
         error(str(e))

bdx/index.py

@@ -593,11 +593,13 @@ def open(directory: Path | str, readonly: bool = False) -> "SymbolIndex":
         return index
 
     @staticmethod
-    def open_shard(directory: Path | str) -> "SymbolIndex":
+    def open_shard(
+        directory: Path | str, readonly: bool = False
+    ) -> "SymbolIndex":
         """Open a writable shard for index in given directory."""
         for path in SymbolIndex.generate_shard_paths(Path(directory) / "db"):
             try:
-                return SymbolIndex(path, readonly=False, is_shard=True)
+                return SymbolIndex(path, readonly=readonly, is_shard=True)
             except Exception:
                 pass
 
@@ -928,11 +930,13 @@ def __init__(
         should_quit: Callable[[], bool],
         index_path: Path,
         use_compilation_database: bool,
+        dry_run: bool,
     ):
         self.options = options
         self.should_quit = should_quit
         self.index_path = index_path
         self.use_compilation_database = use_compilation_database
+        self.dry_run = dry_run
 
         self._job_queue: Queue[Path]
         self._result_queue: Queue[int]
@@ -1025,9 +1029,16 @@ def _worker(self):
                 except QueueEmpty:
                     continue
 
-                result = _index_single_file(
-                    index, path, self.options, self.use_compilation_database
-                )
+                if self.dry_run:
+                    print(f"index {path}")
+                    result = 1
+                else:
+                    result = _index_single_file(
+                        index,
+                        path,
+                        self.options,
+                        self.use_compilation_database,
+                    )
 
                 self._result_queue.put(result)
 
@@ -1039,6 +1050,7 @@ def index_binary_directory(
     use_compilation_database: bool = False,
     reindex: bool = False,
     exclusions: Optional[Collection[Exclusion]] = None,
+    dry_run: bool = False,
 ) -> IndexingStats:
     """Index the given directory."""
     stats = IndexingStats()
@@ -1052,8 +1064,15 @@ def index_binary_directory(
 
     bindir_path = Path(directory)
 
-    with SymbolIndex.open(index_path, readonly=False) as index:
-        if index.binary_dir() is None:
+    with SymbolIndex.open(index_path, readonly=dry_run) as index:
+
+        def delete_file(path):
+            if dry_run:
+                print(f"delete {path}")
+            else:
+                index.delete_file(path)
+
+        if index.binary_dir() is None and not dry_run:
             index.set_binary_dir(bindir_path)
 
         saved_exclusions = list(index.exclusions())
@@ -1089,19 +1108,20 @@ def index_binary_directory(
             desc="Removing outdated files",
             leave=False,
         ):
-            index.delete_file(file)
+            delete_file(file)
             debug("File modified: {}", file)
         for file in make_progress_bar(
             deleted_files,
             desc="Removing deleted files",
             leave=False,
         ):
-            index.delete_file(file)
+            delete_file(file)
             debug("File deleted: {}", file)
 
         if options.persist_exclusions:
             saved_exclusions.extend(original_exclusions)
-        index.set_exclusions(saved_exclusions)
+        if not dry_run:
+            index.set_exclusions(saved_exclusions)
 
     with (
         sigint_catcher() as interrupted,
@@ -1110,6 +1130,7 @@ def index_binary_directory(
             interrupted,
             index_path,
             use_compilation_database=use_compilation_database,
+            dry_run=dry_run,
         ) as pool,
     ):
         perfile_iterator = pool.index_files(changed_files)