enhance(fs):缩短文件读取流程，减少内存复制。

src-tauri/Cargo.lock

@@ -332,6 +332,7 @@ dependencies = [
  "chrono",
  "image",
  "md-5",
+ "mime_guess",
  "mountpoints",
  "once_cell",
  "serde",
@@ -1617,6 +1618,22 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "mime"
+version = "0.3.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6877bb514081ee2a7ff5ef9de3281f14a4dd4bceac4c09388074a6b5df8a139a"
+
+[[package]]
+name = "mime_guess"
+version = "2.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4192263c238a5f0d0c6bfd21f336a313a4ce1c450542449ca191bb657b4642ef"
+dependencies = [
+ "mime",
+ "unicase",
+]
+
 [[package]]
 name = "miniz_oxide"
 version = "0.6.2"
@@ -3208,6 +3225,15 @@ version = "1.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "497961ef93d974e23eb6f433eb5fe1b7930b659f06d12dec6fc44a8f554c0bba"
 
+[[package]]
+name = "unicase"
+version = "2.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "50f37be617794602aabbeee0be4f259dc1778fabe05e2d67ee8f79326d5cb4f6"
+dependencies = [
+ "version_check",
+]
+
 [[package]]
 name = "unicode-bidi"
 version = "0.3.10"

src-tauri/Cargo.toml

@@ -28,6 +28,7 @@ uuid = "1.3.0"
 mountpoints = "0.2.1"
 md-5 = "0.10.5"
 urlencoding = "2.1.2"
+mime_guess = "2.0.4"
 
 [features]
 # this feature is used for production builds or when `devPath` points to the filesystem

src-tauri/src/protocol.rs

@@ -1,4 +1,4 @@
-use std::{error::Error, io::Cursor, path::Path};
+use std::{error::Error, fs, path::Path};
 
 use tauri::{
     http::{Request, Response, ResponseBuilder},
@@ -32,12 +32,11 @@ pub fn comic_protocol<R: Runtime>(
             .body(Vec::new());
     }
 
-    let content = image::io::Reader::open(path)?.decode()?;
-    let mut bytes: Vec<u8> = Vec::new();
-    content.write_to(&mut Cursor::new(&mut bytes), image::ImageOutputFormat::Png)?;
+    let mimetype = mime_guess::from_path(path);
+    let content = fs::read(path)?;
 
     response_builder
-        .mimetype("image/png")
+        .mimetype(mimetype.first_or_text_plain().essence_str())
         .status(200)
-        .body(bytes)
+        .body(content)
 }