[PoC] misc/io_utils.rs: add rust impl of atomic file save

meson.build

@@ -1,5 +1,5 @@
 project('mpv',
-        'c',
+        ['c', 'rust'],
         license: ['GPL2+', 'LGPL2.1+'],
         version: files('./MPV_VERSION'),
         meson_version: '>=1.3.0',
@@ -11,6 +11,8 @@ project('mpv',
             'cpp_std=c++20',
             'cpp_eh=default',
             'warning_level=2',
+            'rust_std=2021',
+            'build.rust_std=2021',
         ]
 )
 
@@ -1761,6 +1763,13 @@ major = client_h_define.split('|')[0].split('<<')[0].strip('() ')
 minor = client_h_define.split('|')[1].strip('() ')
 client_api_version = major + '.' + minor + '.0'
 
+tempfile_dep = dependency('tempfile', fallback : ['tempfile', 'tempfile_dep'])
+libmpv_rs = static_library('libmpv_rs',
+    'misc/io_utils.rs',
+    rust_abi: 'c',
+    dependencies: tempfile_dep
+)
+
 libmpv = library('mpv', sources, dependencies: dependencies, gnu_symbol_visibility: 'hidden',
                  link_args: cc.get_supported_link_arguments(['-Wl,-Bsymbolic']),
                  version: client_api_version, install: get_option('libmpv'),
@@ -1777,7 +1786,7 @@ if get_option('libmpv')
     install_headers(headers, subdir: 'mpv')
 
     # Allow projects to build with libmpv by cloning into ./subprojects/mpv
-    libmpv_dep = declare_dependency(link_with: libmpv)
+    libmpv_dep = declare_dependency(link_with: [libmpv, libmpv_rs])
     meson.override_dependency('mpv', libmpv_dep)
 endif
 
@@ -1810,7 +1819,7 @@ if get_option('cplayer')
     install_data('etc/mpv-symbolic.svg', install_dir: join_paths(hicolor_dir, 'symbolic', 'apps'))
 
     mpv = executable('mpv', main_fn_source, objects: libmpv.extract_all_objects(recursive: true), dependencies: dependencies,
-                     win_subsystem: get_option('win32-subsystem'), install: true)
+                     link_with: libmpv_rs, win_subsystem: get_option('win32-subsystem'), install: true)
 
     if win32 and get_option('win32-subsystem') != 'console'
         wrapper_sources= 'osdep/win32-console-wrapper.c'

misc/io_utils.c

@@ -56,32 +56,3 @@ int mp_mkostemps(char *template, int suffixlen, int flags)
     errno = EEXIST;
     return -1;
 }
-
-bool mp_save_to_file(const char *filepath, const void *data, size_t size)
-{
-    assert(filepath && data && size);
-
-    bool result = false;
-    char *tmp = talloc_asprintf(NULL, "%sXXXXXX", filepath);
-    int fd = mp_mkostemps(tmp, 0, O_CLOEXEC);
-    if (fd < 0)
-        goto done;
-    FILE *cache = fdopen(fd, "wb");
-    if (!cache) {
-        close(fd);
-        unlink(tmp);
-        goto done;
-    }
-    size_t written = fwrite(data, size, 1, cache);
-    int ret = fclose(cache);
-    if (written > 0 && !ret) {
-        ret = rename(tmp, filepath);
-        result = !ret;
-    } else {
-        unlink(tmp);
-    }
-
-done:
-    talloc_free(tmp);
-    return result;
-}

misc/io_utils.rs

@@ -0,0 +1,61 @@
+/*
+ * I/O utility functions
+ *
+ * This file is part of mpv.
+ *
+ * mpv is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * mpv is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with mpv.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+use std::ffi::c_char;
+use std::ffi::CStr;
+use std::io::Write;
+use std::path::Path;
+use tempfile::NamedTempFile;
+
+#[no_mangle]
+pub extern "C" fn mp_save_to_file(filepath: *const c_char, data: *const u8, size: usize) -> bool
+{
+    if filepath.is_null() || data.is_null() || size == 0 {
+        return false;
+    }
+
+    let c_str = unsafe { CStr::from_ptr(filepath) };
+    let target_path = match c_str.to_str() {
+        Ok(path) => Path::new(path),
+        Err(_) => return false,
+    };
+
+    let dir = match target_path.parent() {
+        Some(dir) => dir,
+        None => return false,
+    };
+
+    let filename = match target_path.file_name() {
+        Some(name) => name,
+        None => return false,
+    };
+
+    let mut temp_file = match NamedTempFile::with_prefix_in(filename, dir) {
+        Ok(file) => file,
+        Err(_) => return false,
+    };
+
+    // Write data to temporary file
+    let written = temp_file.write(unsafe { std::slice::from_raw_parts(data, size) });
+    if written.is_err() {
+        return false;
+    }
+
+    temp_file.persist(&target_path).is_ok()
+}

subprojects/cfg_if.wrap

@@ -0,0 +1,6 @@
+[wrap-file]
+directory = cfg-if-1.0.0
+source_url = https://crates.io/api/v1/crates/cfg-if/1.0.0/download
+source_filename = cfg-if-1.0.0.tar.gz
+source_hash = baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd
+patch_directory = cfg_if

subprojects/fastrand.wrap

@@ -0,0 +1,6 @@
+[wrap-file]
+directory = fastrand-2.3.0
+source_url =  https://crates.io/api/v1/crates/fastrand/2.3.0/download
+source_filename = fastrand-2.3.0.tar.gz
+source_hash = 37909eebbb50d72f9059c3b6d82c0463f2ff062c9e95845c43a6c9c0355411be
+patch_directory = fastrand

subprojects/once_cell.wrap

@@ -0,0 +1,6 @@
+[wrap-file]
+directory = once_cell-1.20.3
+source_url = https://crates.io/api/v1/crates/once_cell/1.20.3/download
+source_filename = once_cell-1.20.3.tar.gz
+source_hash = 945462a4b81e43c4e3ba96bd7b49d834c6f61198356aa858733bc4acf3cbe62e
+patch_directory = once_cell

subprojects/packagefiles/cfg_if/meson.build

@@ -0,0 +1,18 @@
+project(
+    'cfg_if',
+    'rust',
+    version: '1.0.0',
+    license: 'MIT OR Apache-2.0',
+)
+
+lib = static_library(
+    'cfg_if',
+    'src/lib.rs',
+    override_options: ['rust_std=2021', 'build.rust_std=2021'],
+    rust_abi: 'rust',
+    native: true,
+)
+
+cfg_if_dep = declare_dependency(
+    link_with: [lib],
+)

subprojects/packagefiles/fastrand/meson.build

@@ -0,0 +1,24 @@
+project(
+    'fastrand',
+    'rust',
+    version: '2.3.0',
+    license: 'MIT OR Apache-2.0',
+)
+
+rust_args = [
+    '--cfg', 'feature="std"',
+    '--cfg', 'feature="alloc"',
+]
+
+lib = static_library(
+    'fastrand',
+    'src/lib.rs',
+    rust_args: rust_args,
+    override_options: ['rust_std=2021', 'build.rust_std=2021'],
+    rust_abi: 'rust',
+    native: true,
+)
+
+fastrand_dep = declare_dependency(
+    link_with: [lib],
+)

subprojects/packagefiles/once_cell/meson.build

@@ -0,0 +1,23 @@
+project(
+    'once_cell',
+    'rust',
+    version: '1.20.3',
+    license: 'MIT OR Apache-2.0',
+)
+
+rust_args = [
+    '--cfg', 'feature="std"',
+]
+
+lib = static_library(
+    'once_cell',
+    'src/lib.rs',
+    rust_args: rust_args,
+    override_options: ['rust_std=2021', 'build.rust_std=2021'],
+    rust_abi: 'rust',
+    native: true,
+)
+
+once_cell_dep = declare_dependency(
+    link_with: [lib],
+)

subprojects/packagefiles/tempfile/meson.build

@@ -0,0 +1,39 @@
+project(
+    'tempfile',
+    'rust',
+    version: '3.17.1',
+    license: 'MIT OR Apache-2.0',
+)
+
+rust_args = [
+    '-A', 'unused_variables',
+    '--cfg', 'feature="std"',
+]
+
+cfg_if_dep = dependency('cfg_if', fallback: ['cfg_if', 'cfg_if_dep'])
+once_cell_dep = dependency('once_cell', fallback: ['once_cell', 'once_cell_dep'])
+fastrand_dep = dependency('fastrand', fallback: ['fastrand', 'fastrand_dep'])
+
+dependencies = [
+    cfg_if_dep,
+    fastrand_dep,
+    once_cell_dep,
+]
+
+if host_machine.system() == 'windows'
+    dependencies += dependency('windows_sys', fallback: ['windows_sys', 'windows_sys_dep'])
+endif
+
+lib = static_library(
+    'tempfile',
+    'src/lib.rs',
+    rust_args: rust_args,
+    override_options: ['rust_std=2021', 'build.rust_std=2021'],
+    rust_abi: 'rust',
+    native: true,
+    dependencies: dependencies,
+)
+
+tempfile_dep = declare_dependency(
+    link_with: [lib],
+)

subprojects/packagefiles/windows_sys/meson.build

@@ -0,0 +1,29 @@
+project(
+    'windows_sys',
+    'rust',
+    version: '0.59.0',
+    license: 'MIT OR Apache-2.0',
+)
+
+rust_args = [
+    '--cfg', 'feature="Win32"',
+    '--cfg', 'feature="Win32_Storage"',
+    '--cfg', 'feature="Win32_Foundation"',
+    '--cfg', 'feature="Win32_Storage_FileSystem"',
+]
+
+windows_targets_dep = dependency('windows_targets', fallback: ['windows_targets', 'windows_targets_dep'])
+
+lib = static_library(
+    'windows_sys',
+    'src/lib.rs',
+    rust_args: rust_args,
+    override_options: ['rust_std=2021', 'build.rust_std=2021'],
+    rust_abi: 'rust',
+    native: true,
+    dependencies: [windows_targets_dep],
+)
+
+windows_sys_dep = declare_dependency(
+    link_with: [lib],
+)

subprojects/packagefiles/windows_targets/meson.build

@@ -0,0 +1,18 @@
+project(
+    'windows_targets',
+    'rust',
+    version: '0.53.0',
+    license: 'MIT OR Apache-2.0',
+)
+
+lib = static_library(
+    'windows_targets',
+    'src/lib.rs',
+    override_options: ['rust_std=2021', 'build.rust_std=2021'],
+    rust_abi: 'rust',
+    native: true,
+)
+
+windows_targets_dep = declare_dependency(
+    link_with: [lib],
+)

subprojects/tempfile.wrap

@@ -0,0 +1,6 @@
+[wrap-file]
+directory = tempfile-3.17.1
+source_url = https://crates.io/api/v1/crates/tempfile/3.17.1/download
+source_filename = tempfile-3.17.1.tar.gz
+source_hash = 22e5a0acb1f3f55f65cc4a866c361b2fb2a0ff6366785ae6fbb5f85df07ba230
+patch_directory = tempfile

subprojects/windows_sys.wrap

@@ -0,0 +1,6 @@
+[wrap-file]
+directory = windows-sys-0.59.0
+source_url =  https://crates.io/api/v1/crates/windows-sys/0.59.0/download
+source_filename = windows-sys-0.59.0.tar.gz
+source_hash = 1e38bc4d79ed67fd075bcc251a1c39b32a1776bbe92e5bef1f0bf1f8c531853b
+patch_directory = windows_sys

subprojects/windows_targets.wrap

@@ -0,0 +1,6 @@
+[wrap-file]
+directory = windows-targets-0.53.0
+source_url =  https://crates.io/api/v1/crates/windows-targets/0.53.0/download
+source_filename = windows-targets-0.53.0.tar.gz
+source_hash = b1e4c7e8ceaaf9cb7d7507c974735728ab453b67ef8f18febdd7c11fe59dca8b
+patch_directory = windows_targets