From 90dcc1cd30e26c86bbb1cac6544390c6398a83ed Mon Sep 17 00:00:00 2001
From: LoveSy <shana@zju.edu.cn>
Date: Sat, 9 Dec 2023 01:17:19 +0800
Subject: [PATCH] Do not always zero initialize for rust resize vec

---
 native/src/base/include/stream.hpp | 2 +-
 native/src/base/lib.rs             | 7 ++++++-
 native/src/base/stream.cpp         | 6 ++++--
 3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/native/src/base/include/stream.hpp b/native/src/base/include/stream.hpp
index 09b34f3c6..5cb5a1deb 100644
--- a/native/src/base/include/stream.hpp
+++ b/native/src/base/include/stream.hpp
@@ -90,7 +90,7 @@ private:
     rust::Vec<uint8_t> &_data;
     size_t _pos = 0;
 
-    void ensure_size(size_t sz);
+    void ensure_size(size_t sz, bool zero = false);
 };
 
 class file_channel : public channel {
diff --git a/native/src/base/lib.rs b/native/src/base/lib.rs
index e05dc3f5e..286905ac8 100644
--- a/native/src/base/lib.rs
+++ b/native/src/base/lib.rs
@@ -66,5 +66,10 @@ fn set_log_level_state_cxx(level: ffi::LogLevelCxx, enabled: bool) {
 }
 
 fn resize_vec(vec: &mut Vec<u8>, size: usize) {
-    vec.resize(size, 0);
+    if size > vec.len() {
+        vec.reserve(size - vec.len());
+    }
+    unsafe {
+        vec.set_len(size);
+    }
 }
diff --git a/native/src/base/stream.cpp b/native/src/base/stream.cpp
index 3628b14e0..8bebf2eaf 100644
--- a/native/src/base/stream.cpp
+++ b/native/src/base/stream.cpp
@@ -209,15 +209,17 @@ off_t rust_vec_channel::seek(off_t off, int whence) {
         default:
             return -1;
     }
-    ensure_size(np);
+    ensure_size(np, true);
     _pos = np;
     return np;
 }
 
-void rust_vec_channel::ensure_size(size_t sz) {
+void rust_vec_channel::ensure_size(size_t sz, bool zero) {
     size_t old_sz = _data.size();
     if (sz > old_sz) {
         resize_vec(_data, sz);
+        if (zero)
+            memset(_data.data() + old_sz, 0, sz - old_sz);
     }
 }