Fabio/Auxio
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

musikr: reorganize ffi module

Browse source 
Still don't fully like the segregation, but now at least the bridge
unsafety is fully isolated.
This commit is contained in:
Alexander Capehart 2025-02-12 22:31:46 -07:00
parent 86b04eaead
commit 3ecdbf289b
No known key found for this signature in database
GPG key ID: 37DBE3621FE9AD47
12 changed files with 562 additions and 634 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
musikr/src/main/jni/build.rs
View file

@ -47,7 +47,7 @@ fn main() {
} else { } else {
panic!("Unsupported Android target: {}", target); panic!("Unsupported Android target: {}", target);
}; };
let clang_path = env::var("CLANG_PATH").expect("CLANG_PATH env var not set"); let clang_path = env::var("CLANG_PATH").expect("CLANG_PATH env var not set");
let toolchains_marker = "/toolchains"; let toolchains_marker = "/toolchains";
let ndk_path = if let Some(pos) = clang_path.find(toolchains_marker) { let ndk_path = if let Some(pos) = clang_path.find(toolchains_marker) {
@ -114,7 +114,7 @@ fn main() {
// println!("cargo:rustc-link-lib=cc++_static"); // println!("cargo:rustc-link-lib=cc++_static");
// Build the shim and cxx bridge together // Build the shim and cxx bridge together
let mut builder = cxx_build::bridge("src/taglib/ffi.rs"); let mut builder = cxx_build::bridge("src/taglib/bridge.rs");
builder builder
.file("shim/iostream_shim.cpp") .file("shim/iostream_shim.cpp")
.file("shim/file_shim.cpp") .file("shim/file_shim.cpp")

16
musikr/src/main/jni/shim/file_shim.cpp
View file

@ -33,14 +33,14 @@ namespace taglib_shim
return dynamic_cast<TagLib::RIFF::WAV::File *>(file); return dynamic_cast<TagLib::RIFF::WAV::File *>(file);
} }
TagLib::WavPack::File *File_asWavPack(TagLib::File *file) // TagLib::WavPack::File *File_asWavPack(TagLib::File *file)
{ // {
return dynamic_cast<TagLib::WavPack::File *>(file); // return dynamic_cast<TagLib::WavPack::File *>(file);
} // }
TagLib::APE::File *File_asAPE(TagLib::File *file) // TagLib::APE::File *File_asAPE(TagLib::File *file)
{ // {
return dynamic_cast<TagLib::APE::File *>(file); // return dynamic_cast<TagLib::APE::File *>(file);
} // }
} // namespace taglib_shim } // namespace taglib_shim

4
musikr/src/main/jni/shim/file_shim.hpp
View file

@ -23,7 +23,7 @@ namespace taglib_shim
TagLib::FLAC::File *File_asFLAC(TagLib::File *file); TagLib::FLAC::File *File_asFLAC(TagLib::File *file);
TagLib::MP4::File *File_asMP4(TagLib::File *file); TagLib::MP4::File *File_asMP4(TagLib::File *file);
TagLib::RIFF::WAV::File *File_asWAV(TagLib::File *file); TagLib::RIFF::WAV::File *File_asWAV(TagLib::File *file);
TagLib::WavPack::File *File_asWavPack(TagLib::File *file); // TagLib::WavPack::File *File_asWavPack(TagLib::File *file);
TagLib::APE::File *File_asAPE(TagLib::File *file); // TagLib::APE::File *File_asAPE(TagLib::File *file);
} // namespace taglib_shim } // namespace taglib_shim

8
musikr/src/main/jni/src/jni_stream.rs → musikr/src/main/jni/src/jstream.rs
View file

@ -1,4 +1,4 @@
use crate::taglib::TagLibStream; use crate::taglib::stream::IOStream;
use jni::objects::{JObject, JValue}; use jni::objects::{JObject, JValue};
use jni::JNIEnv; use jni::JNIEnv;
use std::io::{Read, Seek, SeekFrom, Write}; use std::io::{Read, Seek, SeekFrom, Write};
@ -12,12 +12,12 @@ impl<'local, 'a> JInputStream<'local, 'a> {
pub fn new( pub fn new(
env: &'a mut JNIEnv<'local>, env: &'a mut JNIEnv<'local>,
input: JObject<'local>, input: JObject<'local>,
) -> Result<Self, jni::errors::Error> { ) -> Self {
Ok(JInputStream { env, input }) Self { env, input }
} }
} }
impl<'local, 'a> TagLibStream for JInputStream<'local, 'a> { impl<'local, 'a> IOStream for JInputStream<'local, 'a> {
fn name(&mut self) -> String { fn name(&mut self) -> String {
// Call the Java name() method safely // Call the Java name() method safely
let name = self let name = self

62
musikr/src/main/jni/src/lib.rs
View file

@ -2,10 +2,12 @@ use jni::objects::{JClass, JObject};
use jni::sys::jstring; use jni::sys::jstring;
use jni::JNIEnv; use jni::JNIEnv;
mod jni_stream;
mod taglib; mod taglib;
mod jstream;
use jni_stream::JInputStream; use taglib::file::FileRef;
use jstream::JInputStream;
pub use taglib::*; pub use taglib::*;
#[no_mangle] #[no_mangle]
@ -15,29 +17,43 @@ pub extern "C" fn Java_org_oxycblt_musikr_metadata_MetadataJNI_openFile<'local>(
input: JObject<'local>, input: JObject<'local>,
) -> jstring { ) -> jstring {
// Create JInputStream from the Java input stream // Create JInputStream from the Java input stream
let stream = match JInputStream::new(&mut env, input) { let stream = JInputStream::new(&mut env, input);
Ok(stream) => stream, let file_ref = FileRef::new(stream);
Err(e) => { // file_ref.file().and_then(|file| {
let error = format!("Failed to create input stream: {}", e); // let audio_properties = file.audio_properties().map(|props| AudioProperties {
let error_str = env // length_in_milliseconds: props.length_in_milliseconds(),
.new_string(error) // bitrate_in_kilobits_per_second: props.bitrate(),
.expect("Couldn't create error string!"); // sample_rate_in_hz: props.sample_rate(),
return error_str.into_raw(); // number_of_channels: props.channels(),
} // });
};
// Create FileRef from the stream // if let Some(vorbis_file) = file.as_vorbis() {
let file_ref = match FileRef::from_stream(stream) { // let xiph_comments = vorbis_file
Some(file_ref) => file_ref, // .xiph_comments()
None => { // .map(|comments| comments.field_list_map().to_hashmap());
let error = "Failed to create File";
let error_str = env
.new_string(error)
.expect("Couldn't create error string!");
return error_str.into_raw();
}
};
// } else if let Some(opus_file) = file.as_opus() {
// let xiph_comments = opus_file
// .xiph_comments()
// .map(|comments| comments.field_list_map().to_hashmap());
// Some(File::Opus {
// audio_properties,
// xiph_comments,
// })
// } else if let Some(flac_file) = file.as_flac() {
// let xiph_comments = flac_file
// .xiph_comments()
// .map(|comments| comments.field_list_map().to_hashmap());
// Some(File::FLAC {
// audio_properties,
// xiph_comments,
// })
// } else {
// Some(File::Unknown { audio_properties })
// }
// });
// Return the title // Return the title
let output = env.new_string("title").expect("Couldn't create string!"); let output = env.new_string("title").expect("Couldn't create string!");
output.into_raw() output.into_raw()

141
musikr/src/main/jni/src/taglib/bridge.rs Normal file
View file

@ -0,0 +1,141 @@
#[cxx::bridge]
mod bridge_impl {
unsafe extern "C++" {
include!("taglib/taglib.h");
include!("taglib/tstring.h");
include!("taglib/tstringlist.h");
include!("taglib/vorbisfile.h");
include!("taglib/xiphcomment.h");
include!("shim/iostream_shim.hpp");
include!("shim/file_shim.hpp");
include!("shim/tk_shim.hpp");
#[namespace = "TagLib"]
#[cxx_name = "FileRef"]
type TFileRef;
#[cxx_name = "isNull"]
fn thisIsNull(self: Pin<&TFileRef>) -> bool;
#[cxx_name = "file"]
fn thisFile(self: Pin<&TFileRef>) -> *mut BaseFile;
#[namespace = "taglib_shim"]
type RustIOStream;
// Create a FileRef from an iostream
#[namespace = "taglib_shim"]
unsafe fn new_rust_iostream(stream: *mut RustStream) -> UniquePtr<RustIOStream>;
#[namespace = "taglib_shim"]
type RustStream;
#[namespace = "taglib_shim"]
fn new_FileRef_from_stream(stream: UniquePtr<RustIOStream>) -> UniquePtr<TFileRef>;
#[namespace = "TagLib"]
#[cxx_name = "File"]
type BaseFile;
#[cxx_name = "audioProperties"]
fn thisAudioProperties(self: Pin<&BaseFile>) -> *mut AudioProperties;
#[namespace = "TagLib"]
type AudioProperties;
#[cxx_name = "lengthInMilliseconds"]
fn thisLengthInMilliseconds(self: Pin<&AudioProperties>) -> i32;
#[cxx_name = "bitrate"]
fn thisBitrate(self: Pin<&AudioProperties>) -> i32;
#[cxx_name = "sampleRate"]
fn thisSampleRate(self: Pin<&AudioProperties>) -> i32;
#[cxx_name = "channels"]
fn thisChannels(self: Pin<&AudioProperties>) -> i32;
#[namespace = "TagLib::Ogg"]
#[cxx_name = "File"]
type OggFile;
#[namespace = "TagLib::Ogg"]
type XiphComment;
#[cxx_name = "fieldListMap"]
unsafe fn thisFieldListMap(self: Pin<&XiphComment>) -> &SimplePropertyMap;
#[namespace = "TagLib::Ogg::Vorbis"]
#[cxx_name = "File"]
type VorbisFile;
#[cxx_name = "tag"]
unsafe fn vorbisThisTag(self: Pin<&VorbisFile>) -> *mut XiphComment;
#[namespace = "TagLib::Ogg::Opus"]
#[cxx_name = "File"]
type OpusFile;
#[cxx_name = "tag"]
unsafe fn opusThisTag(self: Pin<&OpusFile>) -> *mut XiphComment;
#[namespace = "TagLib::FLAC"]
#[cxx_name = "File"]
type FLACFile;
#[cxx_name = "xiphComment"]
unsafe fn flacThisXiphComment(self: Pin<&mut FLACFile>, create: bool) -> *mut XiphComment;
#[namespace = "TagLib::MPEG"]
#[cxx_name = "File"]
type MPEGFile;
#[namespace = "TagLib::MP4"]
#[cxx_name = "File"]
type MP4File;
#[namespace = "TagLib::RIFF::WAV"]
#[cxx_name = "File"]
type WAVFile;
// #[namespace = "TagLib::WavPack"]
// #[cxx_name = "File"]
// type WavPackFile;
// #[namespace = "TagLib::APE"]
// #[cxx_name = "File"]
// type APEFile;
#[namespace = "taglib_shim"]
unsafe fn File_asVorbis(file: *mut BaseFile) -> *mut VorbisFile;
#[namespace = "taglib_shim"]
unsafe fn File_asOpus(file: *mut BaseFile) -> *mut OpusFile;
#[namespace = "taglib_shim"]
unsafe fn File_asMPEG(file: *mut BaseFile) -> *mut MPEGFile;
#[namespace = "taglib_shim"]
unsafe fn File_asFLAC(file: *mut BaseFile) -> *mut FLACFile;
#[namespace = "taglib_shim"]
unsafe fn File_asMP4(file: *mut BaseFile) -> *mut MP4File;
#[namespace = "taglib_shim"]
unsafe fn File_asWAV(file: *mut BaseFile) -> *mut WAVFile;
// #[namespace = "taglib_shim"]
// unsafe fn File_asWavPack(file: *mut BaseFile) -> *mut WavPackFile;
// #[namespace = "taglib_shim"]
// unsafe fn File_asAPE(file: *mut BaseFile) -> *mut APEFile;
#[namespace = "TagLib"]
type SimplePropertyMap;
#[namespace = "taglib_shim"]
fn SimplePropertyMap_to_vector(
field_list_map: Pin<&SimplePropertyMap>,
) -> UniquePtr<CxxVector<Property>>;
#[namespace = "taglib_shim"]
type Property;
#[cxx_name = "key"]
fn thisKey(self: Pin<&Property>) -> &TString;
#[cxx_name = "value"]
unsafe fn thisValue(self: Pin<&Property>) -> &TStringList;
#[namespace = "TagLib"]
#[cxx_name = "String"]
type TString;
#[cxx_name = "toCString"]
unsafe fn thisToCString(self: Pin<&TString>, unicode: bool) -> *const c_char;
#[namespace = "TagLib"]
#[cxx_name = "StringList"]
type TStringList;
#[namespace = "taglib_shim"]
fn StringList_to_vector(string_list: Pin<&TStringList>) -> UniquePtr<CxxVector<TString>>;
}
}
pub use bridge_impl::*;

457
musikr/src/main/jni/src/taglib/ffi.rs
View file

@ -1,457 +0,0 @@
use std::collections::HashMap;
use std::ffi::CStr;
use std::pin::{pin, Pin};
use std::string::ToString;
#[cxx::bridge]
pub(crate) mod bindings {
unsafe extern "C++" {
include!("taglib/taglib.h");
include!("taglib/tstring.h");
include!("taglib/tstringlist.h");
include!("taglib/vorbisfile.h");
include!("taglib/xiphcomment.h");
include!("shim/iostream_shim.hpp");
include!("shim/file_shim.hpp");
include!("shim/tk_shim.hpp");
#[namespace = "TagLib"]
type FileRef;
#[cxx_name = "isNull"]
fn thisIsNull(self: Pin<&FileRef>) -> bool;
#[cxx_name = "file"]
fn thisFile(self: Pin<&FileRef>) -> *mut BaseFile;
#[namespace = "taglib_shim"]
type RustIOStream;
// Create a FileRef from an iostream
#[namespace = "taglib_shim"]
unsafe fn new_rust_iostream(stream: *mut RustStream) -> UniquePtr<RustIOStream>;
#[namespace = "taglib_shim"]
type RustStream;
#[namespace = "taglib_shim"]
fn new_FileRef_from_stream(stream: UniquePtr<RustIOStream>) -> UniquePtr<FileRef>;
#[namespace = "TagLib"]
#[cxx_name = "File"]
type BaseFile;
#[cxx_name = "audioProperties"]
fn thisAudioProperties(self: Pin<&BaseFile>) -> *mut AudioProperties;
#[namespace = "TagLib"]
type AudioProperties;
#[cxx_name = "lengthInMilliseconds"]
fn thisLengthInMilliseconds(self: Pin<&AudioProperties>) -> i32;
#[cxx_name = "bitrate"]
fn thisBitrate(self: Pin<&AudioProperties>) -> i32;
#[cxx_name = "sampleRate"]
fn thisSampleRate(self: Pin<&AudioProperties>) -> i32;
#[cxx_name = "channels"]
fn thisChannels(self: Pin<&AudioProperties>) -> i32;
#[namespace = "TagLib::Ogg"]
#[cxx_name = "File"]
type OggFile;
#[namespace = "TagLib::Ogg"]
type XiphComment;
#[cxx_name = "fieldListMap"]
unsafe fn thisFieldListMap(self: Pin<&XiphComment>) -> &SimplePropertyMap;
#[namespace = "TagLib::Ogg::Vorbis"]
#[cxx_name = "File"]
type VorbisFile;
#[cxx_name = "tag"]
unsafe fn vorbisThisTag(self: Pin<&VorbisFile>) -> *mut XiphComment;
#[namespace = "TagLib::Ogg::Opus"]
#[cxx_name = "File"]
type OpusFile;
#[cxx_name = "tag"]
unsafe fn opusThisTag(self: Pin<&OpusFile>) -> *mut XiphComment;
#[namespace = "TagLib::FLAC"]
#[cxx_name = "File"]
type FLACFile;
#[cxx_name = "xiphComment"]
unsafe fn flacThisXiphComment(self: Pin<&mut FLACFile>, create: bool) -> *mut XiphComment;
#[namespace = "TagLib::MPEG"]
#[cxx_name = "File"]
type MPEGFile;
#[namespace = "TagLib::MP4"]
#[cxx_name = "File"]
type MP4File;
#[namespace = "TagLib::RIFF::WAV"]
#[cxx_name = "File"]
type WAVFile;
#[namespace = "TagLib::WavPack"]
#[cxx_name = "File"]
type WavPackFile;
#[namespace = "TagLib::APE"]
#[cxx_name = "File"]
type APEFile;
#[namespace = "taglib_shim"]
unsafe fn File_asVorbis(file: *mut BaseFile) -> *mut VorbisFile;
#[namespace = "taglib_shim"]
unsafe fn File_asOpus(file: *mut BaseFile) -> *mut OpusFile;
#[namespace = "taglib_shim"]
unsafe fn File_asMPEG(file: *mut BaseFile) -> *mut MPEGFile;
#[namespace = "taglib_shim"]
unsafe fn File_asFLAC(file: *mut BaseFile) -> *mut FLACFile;
#[namespace = "taglib_shim"]
unsafe fn File_asMP4(file: *mut BaseFile) -> *mut MP4File;
#[namespace = "taglib_shim"]
unsafe fn File_asWAV(file: *mut BaseFile) -> *mut WAVFile;
#[namespace = "taglib_shim"]
unsafe fn File_asWavPack(file: *mut BaseFile) -> *mut WavPackFile;
#[namespace = "taglib_shim"]
unsafe fn File_asAPE(file: *mut BaseFile) -> *mut APEFile;
#[namespace = "TagLib"]
type SimplePropertyMap;
#[namespace = "taglib_shim"]
fn SimplePropertyMap_to_vector(
field_list_map: Pin<&SimplePropertyMap>,
) -> UniquePtr<CxxVector<Property>>;
#[namespace = "taglib_shim"]
type Property;
#[cxx_name = "key"]
fn thisKey(self: Pin<&Property>) -> &TString;
#[cxx_name = "value"]
unsafe fn thisValue(self: Pin<&Property>) -> &TStringList;
#[namespace = "TagLib"]
#[cxx_name = "String"]
type TString;
#[cxx_name = "toCString"]
unsafe fn thisToCString(self: Pin<&TString>, unicode: bool) -> *const c_char;
#[namespace = "TagLib"]
#[cxx_name = "StringList"]
type TStringList;
#[namespace = "taglib_shim"]
fn StringList_to_vector(string_list: Pin<&TStringList>) -> UniquePtr<CxxVector<TString>>;
}
}
impl bindings::FileRef {
pub fn file_or(&self) -> Option<&mut bindings::BaseFile> {
let file = unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The file data is a pointer that does not depend on the
// address of self.
let this = Pin::new_unchecked(&*self);
// Note: This is not the rust ptr "is_null", but a taglib isNull method
// that checks for file validity. Without this check, we can get corrupted
// file ptrs.
if !this.thisIsNull() {
Some(this.thisFile())
} else {
None
}
};
file.and_then(|file| unsafe {
// SAFETY:
// - This points to a C++ FFI type ensured to be aligned by cxx's codegen.
// - The null-safe version is being used.
// - This points to a C++FFI type ensured to be valid by cxx's codegen.
// - There are no datapaths that will yield any mutable pointers or references
// to this, ensuring that it will not be mutated as per the aliasing rules.
file.as_mut()
})
}
}
impl bindings::BaseFile {
pub fn audio_properties(&self) -> Option<&bindings::AudioProperties> {
let props = unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The audio properties data is a pointer that does not depend on the
// address of self.
let this: Pin<&bindings::BaseFile> = Pin::new_unchecked(self);
this.thisAudioProperties()
};
unsafe {
// SAFETY:
// - This points to a C++ FFI type ensured to be aligned by cxx's codegen.
// - The null-safe version is being used.
// - This points to a C++FFI type ensured to be valid by cxx's codegen.
// - There are no datapaths that will yield any mutable pointers or references
// to this, ensuring that it will not be mutated as per the aliasing rules.
props.as_ref()
}
}
pub fn as_opus(&mut self) -> Option<&mut bindings::OpusFile> {
let ptr_self = self as *mut Self;
let opus_file = unsafe {
// SAFETY:
// This FFI function will be a simple C++ dynamic_cast, which checks if
// the file can be cased down to an opus file. If the cast fails, a null
// pointer is returned, which will be handled by as_ref's null checking.
bindings::File_asOpus(ptr_self)
};
unsafe {
// SAFETY:
// - This points to a C++ FFI type ensured to be aligned by cxx's codegen.
// - The null-safe version is being used.
// - This points to a C++FFI type ensured to be valid by cxx's codegen.
// - There are no datapaths that will yield any mutable pointers or references
// to this, ensuring that it will not be mutated as per the aliasing rules.
opus_file.as_mut()
}
}
pub fn as_vorbis(&mut self) -> Option<&bindings::VorbisFile> {
let ptr_self = self as *mut Self;
let vorbis_file = unsafe {
// SAFETY:
// This FFI function will be a simple C++ dynamic_cast, which checks if
// the file can be cased down to an opus file. If the cast fails, a null
// pointer is returned, which will be handled by as_ref's null checking.
bindings::File_asVorbis(ptr_self)
};
unsafe {
// SAFETY:
// - This points to a C++ FFI type ensured to be aligned by cxx's codegen.
// - The null-safe version is being used.
// - This points to a C++FFI type ensured to be valid by cxx's codegen.
// - There are no datapaths that will yield any mutable pointers or references
// to this, ensuring that it will not be mutated as per the aliasing rules.
vorbis_file.as_ref()
}
}
pub fn as_flac(&mut self) -> Option<&mut bindings::FLACFile> {
let ptr_self = self as *mut Self;
let flac_file = unsafe {
// SAFETY:
// This FFI function will be a simple C++ dynamic_cast, which checks if
// the file can be cased down to an opus file. If the cast fails, a null
// pointer is returned, which will be handled by as_ref's null checking.
bindings::File_asFLAC(ptr_self)
};
unsafe {
// SAFETY:
// - This points to a C++ FFI type ensured to be aligned by cxx's codegen.
// - The null-safe version is being used.
// - This points to a C++FFI type ensured to be valid by cxx's codegen.
// - There are no datapaths that will yield any mutable pointers or references
// to this, ensuring that it will not be mutated as per the aliasing rules.
flac_file.as_mut()
}
}
}
impl bindings::AudioProperties {
pub fn length_in_milliseconds(&self) -> i32 {
unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value is copied and thus not dependent on the address of self.
let this = Pin::new_unchecked(self);
this.thisLengthInMilliseconds()
}
}
pub fn bitrate(&self) -> i32 {
unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value is copied and thus not dependent on the address of self.
let this = Pin::new_unchecked(self);
this.thisBitrate()
}
}
pub fn sample_rate(&self) -> i32 {
unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value is copied and thus not dependent on the address of self.
let this = Pin::new_unchecked(self);
this.thisSampleRate()
}
}
pub fn channels(&self) -> i32 {
unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value is copied and thus not dependent on the address of self.
let this = Pin::new_unchecked(self);
this.thisChannels()
}
}
}
impl bindings::OpusFile {
pub fn xiph_comments(&self) -> Option<&bindings::XiphComment> {
let tag = unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value is a pointer that does not depend on the address of self.
let this = Pin::new_unchecked(self);
this.opusThisTag()
};
unsafe {
// SAFETY: This pointer is a valid type, and can only used and accessed
// via this function and thus cannot be mutated, satisfying the aliasing rules.
tag.as_ref()
}
}
}
impl bindings::VorbisFile {
pub fn xiph_comments(&self) -> Option<&bindings::XiphComment> {
let tag = unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value is a pointer that does not depend on the address of self.
let this = Pin::new_unchecked(self);
this.vorbisThisTag()
};
unsafe {
// SAFETY: This pointer is a valid type, and can only used and accessed
// via this function and thus cannot be mutated, satisfying the aliasing rules.
tag.as_ref()
}
}
}
impl bindings::FLACFile {
pub fn xiph_comments(&mut self) -> Option<&bindings::XiphComment> {
let tag = unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value is a pointer that does not depend on the address of self.
let this = Pin::new_unchecked(self);
// SAFETY: This is a C++ FFI function ensured to call correctly.
this.flacThisXiphComment(false)
};
unsafe {
// SAFETY: This pointer is a valid type, and can only used and accessed
// via this function and thus cannot be mutated, satisfying the aliasing rules.
tag.as_ref()
}
}
}
impl bindings::XiphComment {
pub fn field_list_map(&self) -> &bindings::SimplePropertyMap {
unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value is a reference that does not depend on the address of self.
let this = Pin::new_unchecked(self);
this.thisFieldListMap()
}
}
}
impl bindings::SimplePropertyMap {
pub fn to_hashmap(&self) -> HashMap<String, Vec<String>> {
let cxx_vec = unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value is a unique_ptr to a copied vector that is not dependent
// on the address of self.
let this = Pin::new_unchecked(self);
bindings::SimplePropertyMap_to_vector(this)
};
cxx_vec.iter().map(|property| property.to_tuple()).collect()
}
}
impl bindings::Property {
pub fn to_tuple(&self) -> (String, Vec<String>) {
unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The values returned are copied and thus not dependent on the address
// of self.
let this = Pin::new_unchecked(self);
let key = this.thisKey().to_string();
let value = this.thisValue().to_vec();
(key, value)
}
}
}
impl ToString for bindings::TString {
fn to_string(&self) -> String {
let c_str = unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value returned are pointers and thus not dependent on the address
// of self.
let this: Pin<&bindings::TString> = Pin::new_unchecked(self);
this.thisToCString(true)
};
unsafe {
// SAFETY:
// - This is a C-string returned by a C++ method guaranteed to have
// a null terminator.
// - This C-string is fully allocated and owned by the TagString instance,
// in a continous block from start to null terminator.
// - This C-string will be non-null even if empty.
// - This pointer will not be mutated before it's entirely copied into
// rust.
// - This C-string is copied to a rust string before TagString is destroyed.
CStr::from_ptr(c_str)
}
.to_string_lossy()
.to_string()
}
}
impl bindings::TStringList {
pub fn to_vec(&self) -> Vec<String> {
let cxx_values = unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value returned is a unique ptr to a copied vector that is not
// dependent on the address of self.
let this = Pin::new_unchecked(self);
bindings::StringList_to_vector(this)
};
cxx_values.iter().map(|value| value.to_string()).collect()
}
}

189
musikr/src/main/jni/src/taglib/file.rs Normal file
View file

@ -0,0 +1,189 @@
use cxx::UniquePtr;
use super::bridge::{self, TFileRef};
pub use super::bridge::{BaseFile as File, AudioProperties};
use super::xiph::{OpusFile, VorbisFile, FLACFile};
use super::stream::BridgeStream;
use super::stream::IOStream;
use std::pin::Pin;
use std::marker::PhantomData;
pub struct FileRef<'a, T: IOStream + 'a> {
data: PhantomData<&'a T>,
ptr: UniquePtr<TFileRef>
}
impl <'a, T: IOStream + 'a> FileRef<'a, T> {
pub fn new(stream: T) -> FileRef<'a, T> {
let bridge_stream = BridgeStream::new(stream);
let raw_stream = Box::into_raw(Box::new(bridge_stream)) as *mut bridge::RustStream;
let iostream = unsafe { bridge::new_rust_iostream(raw_stream) };
let file_ref = bridge::new_FileRef_from_stream(iostream);
FileRef {
data: PhantomData::<&'a T>,
ptr: file_ref
}
}
pub fn file(&self) -> Option<&mut File> {
let file = unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The file data is a pointer that does not depend on the
// address of self.
let this = Pin::new_unchecked(&*self.ptr);
// Note: This is not the rust ptr "is_null", but a taglib isNull method
// that checks for file validity. Without this check, we can get corrupted
// file ptrs.
if !this.thisIsNull() {
Some(this.thisFile())
} else {
None
}
};
file.and_then(|file| unsafe {
// SAFETY:
// - This points to a C++ FFI type ensured to be aligned by cxx's codegen.
// - The null-safe version is being used.
// - This points to a C++FFI type ensured to be valid by cxx's codegen.
// - There are no datapaths that will yield any mutable pointers or references
// to this, ensuring that it will not be mutated as per the aliasing rules.
file.as_mut()
})
}
}
impl File {
pub fn audio_properties(&self) -> Option<&AudioProperties> {
let props = unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The audio properties data is a pointer that does not depend on the
// address of self.
let this: Pin<&File> = Pin::new_unchecked(self);
this.thisAudioProperties()
};
unsafe {
// SAFETY:
// - This points to a C++ FFI type ensured to be aligned by cxx's codegen.
// - The null-safe version is being used.
// - This points to a C++FFI type ensured to be valid by cxx's codegen.
// - There are no datapaths that will yield any mutable pointers or references
// to this, ensuring that it will not be mutated as per the aliasing rules.
props.as_ref()
}
}
pub fn as_opus(&mut self) -> Option<&mut OpusFile> {
let ptr_self = self as *mut Self;
let opus_file = unsafe {
// SAFETY:
// This FFI function will be a simple C++ dynamic_cast, which checks if
// the file can be cased down to an opus file. If the cast fails, a null
// pointer is returned, which will be handled by as_ref's null checking.
bridge::File_asOpus(ptr_self)
};
unsafe {
// SAFETY:
// - This points to a C++ FFI type ensured to be aligned by cxx's codegen.
// - The null-safe version is being used.
// - This points to a C++FFI type ensured to be valid by cxx's codegen.
// - There are no datapaths that will yield any mutable pointers or references
// to this, ensuring that it will not be mutated as per the aliasing rules.
opus_file.as_mut()
}
}
pub fn as_vorbis(&mut self) -> Option<&VorbisFile> {
let ptr_self = self as *mut Self;
let vorbis_file = unsafe {
// SAFETY:
// This FFI function will be a simple C++ dynamic_cast, which checks if
// the file can be cased down to an opus file. If the cast fails, a null
// pointer is returned, which will be handled by as_ref's null checking.
bridge::File_asVorbis(ptr_self)
};
unsafe {
// SAFETY:
// - This points to a C++ FFI type ensured to be aligned by cxx's codegen.
// - The null-safe version is being used.
// - This points to a C++FFI type ensured to be valid by cxx's codegen.
// - There are no datapaths that will yield any mutable pointers or references
// to this, ensuring that it will not be mutated as per the aliasing rules.
vorbis_file.as_ref()
}
}
pub fn as_flac(&mut self) -> Option<&mut FLACFile> {
let ptr_self = self as *mut Self;
let flac_file = unsafe {
// SAFETY:
// This FFI function will be a simple C++ dynamic_cast, which checks if
// the file can be cased down to an opus file. If the cast fails, a null
// pointer is returned, which will be handled by as_ref's null checking.
bridge::File_asFLAC(ptr_self)
};
unsafe {
// SAFETY:
// - This points to a C++ FFI type ensured to be aligned by cxx's codegen.
// - The null-safe version is being used.
// - This points to a C++FFI type ensured to be valid by cxx's codegen.
// - There are no datapaths that will yield any mutable pointers or references
// to this, ensuring that it will not be mutated as per the aliasing rules.
flac_file.as_mut()
}
}
}
impl AudioProperties {
pub fn length_in_milliseconds(&self) -> i32 {
unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value is copied and thus not dependent on the address of self.
let this = Pin::new_unchecked(self);
this.thisLengthInMilliseconds()
}
}
pub fn bitrate(&self) -> i32 {
unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value is copied and thus not dependent on the address of self.
let this = Pin::new_unchecked(self);
this.thisBitrate()
}
}
pub fn sample_rate(&self) -> i32 {
unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value is copied and thus not dependent on the address of self.
let this = Pin::new_unchecked(self);
this.thisSampleRate()
}
}
pub fn channels(&self) -> i32 {
unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value is copied and thus not dependent on the address of self.
let this = Pin::new_unchecked(self);
this.thisChannels()
}
}
}

128
musikr/src/main/jni/src/taglib/mod.rs
View file

@ -1,124 +1,6 @@
mod ffi; mod bridge;
mod stream;
use ffi::bindings; pub mod file;
use std::collections::HashMap; pub mod stream;
pub use stream::{RustStream, TagLibStream}; pub mod tk;
pub mod xiph;
type XiphComments = HashMap<String, Vec<String>>;
pub enum File {
Unknown {
audio_properties: Option<AudioProperties>,
},
MP3 {
audio_properties: Option<AudioProperties>,
},
FLAC {
audio_properties: Option<AudioProperties>,
xiph_comments: Option<XiphComments>,
},
MP4 {
audio_properties: Option<AudioProperties>,
},
OGG {
audio_properties: Option<AudioProperties>,
xiph_comments: Option<XiphComments>,
},
Opus {
audio_properties: Option<AudioProperties>,
xiph_comments: Option<XiphComments>,
},
WAV {
audio_properties: Option<AudioProperties>,
},
WavPack {
audio_properties: Option<AudioProperties>,
},
APE {
audio_properties: Option<AudioProperties>,
},
}
/// Audio properties of a media file
#[derive(Default)]
pub struct AudioProperties {
pub length_in_milliseconds: i32,
pub bitrate_in_kilobits_per_second: i32,
pub sample_rate_in_hz: i32,
pub number_of_channels: i32,
}
// Safe wrapper for FileRef that owns extracted data
pub struct FileRef {
file: Option<File>,
}
impl FileRef {
/// Create a new FileRef from a stream implementing TagLibStream
pub fn from_stream<'a, T: TagLibStream + 'a>(stream: T) -> Option<Self> {
// Create the RustStream wrapper
let rust_stream = stream::RustStream::new(stream);
// Convert to raw pointer for FFI
let raw_stream = Box::into_raw(Box::new(rust_stream)) as *mut bindings::RustStream;
// Create the RustIOStream C++ wrapper
let iostream = unsafe { ffi::bindings::new_rust_iostream(raw_stream) };
// Create FileRef from iostream
let file_ref = ffi::bindings::new_FileRef_from_stream(iostream);
if file_ref.is_null() {
return None;
}
// Extract data from C++ objects
let file = file_ref.file_or().and_then(|file| {
let audio_properties = file.audio_properties().map(|props| AudioProperties {
length_in_milliseconds: props.length_in_milliseconds(),
bitrate_in_kilobits_per_second: props.bitrate(),
sample_rate_in_hz: props.sample_rate(),
number_of_channels: props.channels(),
});
if let Some(vorbis_file) = file.as_vorbis() {
let xiph_comments = vorbis_file
.xiph_comments()
.map(|comments| comments.field_list_map().to_hashmap());
Some(File::OGG {
audio_properties,
xiph_comments,
})
} else if let Some(opus_file) = file.as_opus() {
let xiph_comments = opus_file
.xiph_comments()
.map(|comments| comments.field_list_map().to_hashmap());
Some(File::Opus {
audio_properties,
xiph_comments,
})
} else if let Some(flac_file) = file.as_flac() {
let xiph_comments = flac_file
.xiph_comments()
.map(|comments| comments.field_list_map().to_hashmap());
Some(File::FLAC {
audio_properties,
xiph_comments,
})
} else {
Some(File::Unknown { audio_properties })
}
});
// Clean up C++ objects - they will be dropped when file_ref is dropped
drop(file_ref);
Some(FileRef { file })
}
pub fn file(&self) -> &Option<File> {
&self.file
}
}

28
musikr/src/main/jni/src/taglib/stream.rs
View file

@ -2,25 +2,23 @@ use std::ffi::{c_void, CString};
use std::io::{Read, Seek, SeekFrom, Write}; use std::io::{Read, Seek, SeekFrom, Write};
use std::os::raw::c_char; use std::os::raw::c_char;
// Trait that must be implemented by Rust streams to be used with TagLib pub trait IOStream: Read + Write + Seek {
pub trait TagLibStream: Read + Write + Seek {
fn name(&mut self) -> String; fn name(&mut self) -> String;
fn is_readonly(&self) -> bool; fn is_readonly(&self) -> bool;
} }
// Opaque type for C++
#[repr(C)] #[repr(C)]
pub struct RustStream<'a>(Box<dyn TagLibStream + 'a>); pub(super) struct BridgeStream<'a>(Box<dyn IOStream + 'a>);
impl<'a> RustStream<'a> { impl<'a> BridgeStream<'a> {
pub fn new<T: TagLibStream + 'a>(stream: T) -> Self { pub fn new<T: IOStream + 'a>(stream: T) -> Self {
RustStream(Box::new(stream)) BridgeStream(Box::new(stream))
} }
} }
#[no_mangle] #[no_mangle]
pub extern "C" fn rust_stream_name(stream: *mut c_void) -> *const c_char { pub extern "C" fn rust_stream_name(stream: *mut c_void) -> *const c_char {
let stream = unsafe { &mut *(stream as *mut RustStream<'_>) }; let stream = unsafe { &mut *(stream as *mut BridgeStream<'_>) };
let name = stream.0.name(); let name = stream.0.name();
// Note: This leaks memory, but TagLib only calls this once during construction // Note: This leaks memory, but TagLib only calls this once during construction
// and keeps the pointer, so it's fine // and keeps the pointer, so it's fine
@ -29,21 +27,21 @@ pub extern "C" fn rust_stream_name(stream: *mut c_void) -> *const c_char {
#[no_mangle] #[no_mangle]
pub extern "C" fn rust_stream_read(stream: *mut c_void, buffer: *mut u8, length: usize) -> usize { pub extern "C" fn rust_stream_read(stream: *mut c_void, buffer: *mut u8, length: usize) -> usize {
let stream = unsafe { &mut *(stream as *mut RustStream<'_>) }; let stream = unsafe { &mut *(stream as *mut BridgeStream<'_>) };
let buffer = unsafe { std::slice::from_raw_parts_mut(buffer, length) }; let buffer = unsafe { std::slice::from_raw_parts_mut(buffer, length) };
stream.0.read(buffer).unwrap_or(0) stream.0.read(buffer).unwrap_or(0)
} }
#[no_mangle] #[no_mangle]
pub extern "C" fn rust_stream_write(stream: *mut c_void, data: *const u8, length: usize) { pub extern "C" fn rust_stream_write(stream: *mut c_void, data: *const u8, length: usize) {
let stream = unsafe { &mut *(stream as *mut RustStream<'_>) }; let stream = unsafe { &mut *(stream as *mut BridgeStream<'_>) };
let data = unsafe { std::slice::from_raw_parts(data, length) }; let data = unsafe { std::slice::from_raw_parts(data, length) };
stream.0.write_all(data).unwrap(); stream.0.write_all(data).unwrap();
} }
#[no_mangle] #[no_mangle]
pub extern "C" fn rust_stream_seek(stream: *mut c_void, offset: i64, whence: i32) { pub extern "C" fn rust_stream_seek(stream: *mut c_void, offset: i64, whence: i32) {
let stream = unsafe { &mut *(stream as *mut RustStream<'_>) }; let stream = unsafe { &mut *(stream as *mut BridgeStream<'_>) };
let pos = match whence { let pos = match whence {
0 => SeekFrom::Start(offset as u64), 0 => SeekFrom::Start(offset as u64),
1 => SeekFrom::Current(offset), 1 => SeekFrom::Current(offset),
@ -55,20 +53,20 @@ pub extern "C" fn rust_stream_seek(stream: *mut c_void, offset: i64, whence: i32
#[no_mangle] #[no_mangle]
pub extern "C" fn rust_stream_truncate(stream: *mut c_void, length: i64) { pub extern "C" fn rust_stream_truncate(stream: *mut c_void, length: i64) {
let stream = unsafe { &mut *(stream as *mut RustStream<'_>) }; let stream = unsafe { &mut *(stream as *mut BridgeStream<'_>) };
stream.0.seek(SeekFrom::Start(length as u64)).unwrap(); stream.0.seek(SeekFrom::Start(length as u64)).unwrap();
// TODO: Actually implement truncate once we have a better trait bound // TODO: Actually implement truncate once we have a better trait bound
} }
#[no_mangle] #[no_mangle]
pub extern "C" fn rust_stream_tell(stream: *mut c_void) -> i64 { pub extern "C" fn rust_stream_tell(stream: *mut c_void) -> i64 {
let stream = unsafe { &mut *(stream as *mut RustStream<'_>) }; let stream = unsafe { &mut *(stream as *mut BridgeStream<'_>) };
stream.0.seek(SeekFrom::Current(0)).unwrap() as i64 stream.0.seek(SeekFrom::Current(0)).unwrap() as i64
} }
#[no_mangle] #[no_mangle]
pub extern "C" fn rust_stream_length(stream: *mut c_void) -> i64 { pub extern "C" fn rust_stream_length(stream: *mut c_void) -> i64 {
let stream = unsafe { &mut *(stream as *mut RustStream<'_>) }; let stream = unsafe { &mut *(stream as *mut BridgeStream<'_>) };
let current = stream.0.seek(SeekFrom::Current(0)).unwrap(); let current = stream.0.seek(SeekFrom::Current(0)).unwrap();
let end = stream.0.seek(SeekFrom::End(0)).unwrap(); let end = stream.0.seek(SeekFrom::End(0)).unwrap();
stream.0.seek(SeekFrom::Start(current)).unwrap(); stream.0.seek(SeekFrom::Start(current)).unwrap();
@ -77,6 +75,6 @@ pub extern "C" fn rust_stream_length(stream: *mut c_void) -> i64 {
#[no_mangle] #[no_mangle]
pub extern "C" fn rust_stream_is_readonly(stream: *const c_void) -> bool { pub extern "C" fn rust_stream_is_readonly(stream: *const c_void) -> bool {
let stream = unsafe { &*(stream as *const RustStream<'_>) }; let stream = unsafe { &*(stream as *const BridgeStream<'_>) };
stream.0.is_readonly() stream.0.is_readonly()
} }

84
musikr/src/main/jni/src/taglib/tk.rs Normal file
View file

@ -0,0 +1,84 @@
use std::{ffi::CStr, string::ToString};
use std::pin::Pin;
use std::collections::HashMap;
use super::bridge::{self, Property};
pub use super::bridge::{TString, TStringList, SimplePropertyMap};
impl SimplePropertyMap {
pub fn to_hashmap(&self) -> HashMap<String, Vec<String>> {
let cxx_vec = unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value is a unique_ptr to a copied vector that is not dependent
// on the address of self.
let this = Pin::new_unchecked(self);
bridge::SimplePropertyMap_to_vector(this)
};
cxx_vec.iter().map(|property| property.to_tuple()).collect()
}
}
impl Property {
pub fn to_tuple(&self) -> (String, Vec<String>) {
unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The values returned are copied and thus not dependent on the address
// of self.
let this = Pin::new_unchecked(self);
let key = this.thisKey().to_string();
let value = this.thisValue().to_vec();
(key, value)
}
}
}
impl ToString for TString {
fn to_string(&self) -> String {
let c_str = unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value returned are pointers and thus not dependent on the address
// of self.
let this: Pin<&TString> = Pin::new_unchecked(self);
this.thisToCString(true)
};
unsafe {
// SAFETY:
// - This is a C-string returned by a C++ method guaranteed to have
// a null terminator.
// - This C-string is fully allocated and owned by the TagString instance,
// in a continous block from start to null terminator.
// - This C-string will be non-null even if empty.
// - This pointer will not be mutated before it's entirely copied into
// rust.
// - This C-string is copied to a rust string before TagString is destroyed.
CStr::from_ptr(c_str)
}
.to_string_lossy()
.to_string()
}
}
impl TStringList {
pub fn to_vec(&self) -> Vec<String> {
let cxx_values = unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value returned is a unique ptr to a copied vector that is not
// dependent on the address of self.
let this = Pin::new_unchecked(self);
bridge::StringList_to_vector(this)
};
cxx_values.iter().map(|value| value.to_string()).collect()
}
}

75
musikr/src/main/jni/src/taglib/xiph.rs Normal file
View file

@ -0,0 +1,75 @@
pub use super::bridge::{OpusFile, VorbisFile, FLACFile, XiphComment};
use super::tk::SimplePropertyMap;
use std::pin::Pin;
impl OpusFile {
pub fn xiph_comments(&self) -> Option<&XiphComment> {
let tag = unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value is a pointer that does not depend on the address of self.
let this = Pin::new_unchecked(self);
this.opusThisTag()
};
unsafe {
// SAFETY: This pointer is a valid type, and can only used and accessed
// via this function and thus cannot be mutated, satisfying the aliasing rules.
tag.as_ref()
}
}
}
impl VorbisFile {
pub fn xiph_comments(&self) -> Option<&XiphComment> {
let tag = unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value is a pointer that does not depend on the address of self.
let this = Pin::new_unchecked(self);
this.vorbisThisTag()
};
unsafe {
// SAFETY: This pointer is a valid type, and can only used and accessed
// via this function and thus cannot be mutated, satisfying the aliasing rules.
tag.as_ref()
}
}
}
impl FLACFile {
pub fn xiph_comments(&mut self) -> Option<&XiphComment> {
let tag = unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value is a pointer that does not depend on the address of self.
let this = Pin::new_unchecked(self);
// SAFETY: This is a C++ FFI function ensured to call correctly.
this.flacThisXiphComment(false)
};
unsafe {
// SAFETY: This pointer is a valid type, and can only used and accessed
// via this function and thus cannot be mutated, satisfying the aliasing rules.
tag.as_ref()
}
}
}
impl XiphComment {
pub fn field_list_map(&self) -> &SimplePropertyMap {
unsafe {
// SAFETY:
// - This pin is only used in this unsafe scope.
// - The pin is used as a C++ this pointer in the ffi call, which does
// not change address by C++ semantics.
// - The value is a reference that does not depend on the address of self.
let this = Pin::new_unchecked(self);
this.thisFieldListMap()
}
}
}