Ignore user uploads in output files, default output to `/home`

- Adds ignore of user uploaded files in scanning of output files
- Adds ignore of files starting with leading underscores
- Changes default output path to `home`

2 files changed, 20 insertions, 9 deletions

diff --git a/snekbox/memfs.py b/snekbox/memfs.py
index 259f6f7..34e696e 100644
--- a/snekbox/memfs.py
+++ b/snekbox/memfs.py
@@ -4,7 +4,7 @@ from __future__ import annotations
 import logging
 import warnings
 import weakref
-from collections.abc import Generator
+from collections.abc import Generator, Sequence
 from contextlib import suppress
 from pathlib import Path
 from types import TracebackType
@@ -27,7 +27,7 @@ class MemFS:
         instance_size: int,
         root_dir: str | Path = "/memfs",
         home: str = "home",
-        output: str = "output",
+        output: str = "home",
     ) -> None:
         """
         Initialize an in-memory temporary file system.
@@ -97,7 +97,7 @@ class MemFS:
     @property
     def output(self) -> Path:
         """Path to output directory."""
-        return self.home / self._output_name
+        return self.path / self._output_name
 
     def __enter__(self) -> MemFS:
         return self
@@ -120,21 +120,28 @@ class MemFS:
         folder.chmod(chmod)
         return folder
 
-    def files(self, limit: int, pattern: str = "**/*") -> Generator[FileAttachment, None, None]:
+    def files(
+        self, limit: int, pattern: str = "**/*", exclude_files: Sequence[str] = ()
+    ) -> Generator[FileAttachment, None, None]:
         """
         Yields FileAttachments for files found in the output directory.
 
         Args:
             limit: The maximum number of files to parse.
             pattern: The glob pattern to match files against.
+            exclude_files: Files (relative to home directory) to exclude.
         """
         count = 0
         for file in self.output.rglob(pattern):
+            if str(file.relative_to(self.home)) in exclude_files:
+                log.info(f"Skipping excluded file {file!s}")
+                continue
             if count > limit:
                 log.info(f"Max attachments {limit} reached, skipping remaining files")
                 break
             if file.is_file():
                 count += 1
+                log.info(f"Found file {file!s}")
                 yield FileAttachment.from_path(file, relative_to=self.output)
 
     def files_list(
@@ -142,6 +149,7 @@ class MemFS:
         limit: int,
         pattern: str,
         preload_dict: bool = False,
+        exclude_files: Sequence[str] = (),
     ) -> list[FileAttachment]:
         """
         Return a sorted list of file paths within the output directory.
@@ -150,11 +158,11 @@ class MemFS:
             limit: The maximum number of files to parse.
             pattern: The glob pattern to match files against.
             preload_dict: Whether to preload as_dict property data.
-
+            exclude_files: Files (relative to home directory) to exclude.
         Returns:
             List of FileAttachments sorted lexically by path name.
         """
-        res = sorted(self.files(limit, pattern), key=lambda f: f.path)
+        res = sorted(self.files(limit, pattern, exclude_files), key=lambda f: f.path)
         if preload_dict:
             for file in res:
                 # Loads the cached property as attribute
diff --git a/snekbox/nsjail.py b/snekbox/nsjail.py
index ba68a84..d425d35 100644
--- a/snekbox/nsjail.py
+++ b/snekbox/nsjail.py
@@ -53,10 +53,10 @@ class NsJail:
         read_chunk_size: int = 10_000,
         memfs_instance_size: int = 48 * Size.MiB,
         memfs_home: str = "home",
-        memfs_output: str = "output",
+        memfs_output: str = "home",
         files_limit: int | None = 100,
         files_timeout: float | None = 8,
-        files_pattern: str = "**/*",
+        files_pattern: str = "**/[!_]*",
     ):
         """
         Initialize NsJail.
@@ -258,11 +258,14 @@ class NsJail:
             # convert negative exit codes to the `N + 128` form.
             returncode = -nsjail.returncode + 128 if nsjail.returncode < 0 else nsjail.returncode
 
+            # Exclude user uploaded files from output
+            to_exclude = [file.path for file in files]
             # Parse attachments with time limit
             try:
                 attachments = timed(
                     MemFS.files_list,
-                    (fs, self.files_limit, self.files_pattern, True),
+                    (fs, self.files_limit, self.files_pattern),
+                    {"preload_dict": True, "exclude_files": to_exclude},
                     timeout=self.files_timeout,
                 )
                 log.info(f"Found {len(attachments)} files.")