Add standalone media and remote downloads

src/archive.rs

@@ -70,16 +70,33 @@ pub fn decode_page(path: &Path, page: &ArchivePage) -> Result<DecodedPage> {
         bail!("실제 압축 해제 크기가 제한을 초과합니다: {}", page.name);
     }
 
-    let reader = ImageReader::new(Cursor::new(&encoded))
+    decode_image_bytes(&encoded, &page.name)
+}
+
+pub fn decode_image_file(path: &Path, display_name: &str) -> Result<DecodedPage> {
+    let file = File::open(path)
+        .with_context(|| format!("이미지 파일을 열 수 없습니다: {display_name}"))?;
+    let mut encoded = Vec::new();
+    file.take(MAX_ENTRY_SIZE + 1)
+        .read_to_end(&mut encoded)
+        .with_context(|| format!("이미지 파일을 읽을 수 없습니다: {display_name}"))?;
+    if encoded.len() as u64 > MAX_ENTRY_SIZE {
+        bail!("이미지 크기가 제한을 초과합니다: {display_name} (최대 256MB)");
+    }
+    decode_image_bytes(&encoded, display_name)
+}
+
+fn decode_image_bytes(encoded: &[u8], name: &str) -> Result<DecodedPage> {
+    let reader = ImageReader::new(Cursor::new(encoded))
         .with_guessed_format()
-        .with_context(|| format!("이미지 형식을 확인할 수 없습니다: {}", page.name))?;
+        .with_context(|| format!("이미지 형식을 확인할 수 없습니다: {name}"))?;
     let (width, height) = reader
         .into_dimensions()
-        .with_context(|| format!("이미지 크기를 읽을 수 없습니다: {}", page.name))?;
-    validate_dimensions(width, height, &page.name)?;
+        .with_context(|| format!("이미지 크기를 읽을 수 없습니다: {name}"))?;
+    validate_dimensions(width, height, name)?;
 
-    let image = image::load_from_memory(&encoded)
-        .with_context(|| format!("이미지를 디코딩할 수 없습니다: {}", page.name))?;
+    let image = image::load_from_memory(encoded)
+        .with_context(|| format!("이미지를 디코딩할 수 없습니다: {name}"))?;
     let rgba = image.into_rgba8();
 
     Ok(DecodedPage {
@@ -175,4 +192,16 @@ mod tests {
 
         std::fs::remove_file(path).unwrap();
     }
+
+    #[test]
+    fn decodes_a_standalone_image() {
+        let directory = tempfile::tempdir().unwrap();
+        let path = directory.path().join("photo.png");
+        let image = image::RgbaImage::from_pixel(4, 5, image::Rgba([1, 2, 3, 255]));
+        image.save(&path).unwrap();
+
+        let decoded = decode_image_file(&path, "photo.png").unwrap();
+        assert_eq!((decoded.width, decoded.height), (4, 5));
+        assert_eq!(decoded.rgba.len(), 4 * 5 * 4);
+    }
 }