add admin command to delete individual media files

src/service/media.rs

@@ -3,7 +3,7 @@ use std::io::Cursor;
 use image::imageops::FilterType;
 use ruma::{http_headers::ContentDisposition, OwnedMxcUri};
 use tokio::{
-    fs::File,
+    fs::{self, File},
     io::{AsyncReadExt, AsyncWriteExt},
 };
 use tracing::{debug, warn};
@@ -110,6 +110,37 @@ impl Service {
         }
     }
 
+    /// Deletes a media object and all associated thumbnails.
+    #[tracing::instrument(skip(self))]
+    pub(crate) async fn delete(&self, mxc: OwnedMxcUri) -> Result<()> {
+        let (_, key) = self.db.search_file_metadata(mxc.clone(), 0, 0)?;
+
+        let thumbnails = self.db.search_thumbnails_metadata(mxc)?;
+        for (_, thumbnail_key) in thumbnails {
+            self.delete_by_key(thumbnail_key).await?;
+        }
+
+        self.delete_by_key(key).await?;
+
+        Ok(())
+    }
+
+    /// Deletes a specific media key, which may or may not be a thumbnail.
+    ///
+    /// When deleting a non-thumbnail key with this method, the associated
+    /// thumbnails are not deleted.
+    async fn delete_by_key(&self, key: MediaFileKey) -> Result<()> {
+        let path = services().globals.get_media_file(&key);
+        match fs::remove_file(path).await {
+            Ok(()) => (),
+            // The file in the fs may already have been deleted by hand
+            Err(e) if e.kind() == std::io::ErrorKind::NotFound => (),
+            other_error => other_error?,
+        }
+        self.db.delete_file_metadata(key)?;
+        Ok(())
+    }
+
     /// Returns width, height of the thumbnail and whether it should be cropped.
     /// Returns None when the server should send the original file.
     fn thumbnail_properties(