first draft

crates/cdda-paranoia/src/lib.rs

@@ -0,0 +1,314 @@
+#![allow(
+    clippy::missing_safety_doc,
+    clippy::unnecessary_cast,
+    clippy::field_reassign_with_default
+)]
+
+//! C ABI-compatible libcdda_paranoia implementation.
+
+use cdrustanoia_capi_types::*;
+use cdrustanoia_core::device::{
+    host_big_endian, swap_raw16, DiscToc, Drive, InterfaceKind, ReadError, TimedRead,
+    CD_FRAMESIZE_RAW, MAXTRK,
+};
+use cdrustanoia_core::paranoia::Paranoia;
+use libc::{c_char, c_int, c_long, c_void};
+use std::ffi::CStr;
+use std::ptr;
+use std::time::Instant;
+
+pub type ParanoiaCallback = Option<unsafe extern "C" fn(c_long, c_int)>;
+
+struct CAbiDrive {
+    d: *mut CdromDrive,
+    toc: DiscToc,
+    model: String,
+    bigendianp: i32,
+    nsectors: i64,
+    interface: InterfaceKind,
+}
+
+unsafe fn toc_from_d(d: *mut CdromDrive) -> DiscToc {
+    let mut toc = DiscToc::default();
+    if d.is_null() {
+        return toc;
+    }
+    toc.tracks = (*d).tracks;
+    toc.cd_extra = (*d).cd_extra;
+    for i in 0..MAXTRK {
+        toc.entries[i].flags = (*d).disc_toc[i].b_flags;
+        toc.entries[i].track = (*d).disc_toc[i].b_track;
+        toc.entries[i].start_sector = (*d).disc_toc[i].dw_start_sector as i64;
+    }
+    toc
+}
+
+impl CAbiDrive {
+    unsafe fn new(d: *mut CdromDrive) -> Self {
+        let model = if (*d).drive_model.is_null() {
+            String::new()
+        } else {
+            CStr::from_ptr((*d).drive_model)
+                .to_string_lossy()
+                .into_owned()
+        };
+        let interface = match (*d).interface {
+            INTERFACE_COOKED_IOCTL => InterfaceKind::Cooked,
+            INTERFACE_TEST => InterfaceKind::Image,
+            _ => InterfaceKind::SgIo,
+        };
+        Self {
+            d,
+            toc: toc_from_d(d),
+            model,
+            bigendianp: (*d).bigendianp,
+            nsectors: (*d).nsectors as i64,
+            interface,
+        }
+    }
+
+    fn refresh(&mut self) {
+        unsafe {
+            self.toc = toc_from_d(self.d);
+            self.bigendianp = (*self.d).bigendianp;
+            self.nsectors = (*self.d).nsectors as i64;
+        }
+    }
+}
+
+impl Drive for CAbiDrive {
+    fn toc(&self) -> &DiscToc {
+        &self.toc
+    }
+    fn toc_mut(&mut self) -> &mut DiscToc {
+        &mut self.toc
+    }
+    fn opened(&self) -> bool {
+        unsafe { !self.d.is_null() && (*self.d).opened != 0 }
+    }
+    fn read_audio(
+        &mut self,
+        mut buffer: Option<&mut [u8]>,
+        begin: i64,
+        sectors: i64,
+    ) -> Result<usize, ReadError> {
+        unsafe {
+            if self.d.is_null() || (*self.d).opened == 0 {
+                return Err(ReadError::closed());
+            }
+            let f = (*self.d)
+                .read_audio
+                .ok_or_else(|| ReadError::new(libc::EIO, "No read function"))?;
+            let ptr = match buffer.as_mut() {
+                Some(b) => b.as_mut_ptr() as *mut c_void,
+                None => ptr::null_mut(),
+            };
+            let ret = f(self.d, ptr, begin as c_long, sectors as c_long);
+            if ret < 0 {
+                let errno = match ret {
+                    -404 => libc::ENOMEDIUM,
+                    -300 => libc::ENOMEM,
+                    _ => libc::EIO,
+                };
+                return Err(ReadError::new(errno, "SCSI read error"));
+            }
+            let n = ret as usize;
+            if let Some(buf) = buffer.as_mut() {
+                let be = (*self.d).bigendianp;
+                if n > 0 && be >= 0 && (be == 1) != host_big_endian() {
+                    let len = (n * CD_FRAMESIZE_RAW).min(buf.len());
+                    swap_raw16(&mut buf[..len]);
+                }
+            }
+            Ok(n)
+        }
+    }
+    fn read_timed(&mut self, buffer: Option<&mut [u8]>, begin: i64, sectors: i64) -> TimedRead {
+        let started = Instant::now();
+        let result = self.read_audio(buffer, begin, sectors);
+        TimedRead {
+            result,
+            milliseconds: started.elapsed().as_millis() as i32,
+        }
+    }
+    fn speed_set(&mut self, speed: i32) -> i32 {
+        unsafe {
+            if self.d.is_null() {
+                return -405;
+            }
+            match (*self.d).set_speed {
+                Some(f) => f(self.d, speed as c_int),
+                None => -405,
+            }
+        }
+    }
+    fn close(&mut self) {
+        // The paranoia library never closes the caller-owned drive.
+    }
+    fn drive_model(&self) -> &str {
+        &self.model
+    }
+    fn bigendianp(&self) -> i32 {
+        self.bigendianp
+    }
+    fn set_bigendianp(&mut self, value: i32) {
+        self.bigendianp = value;
+        unsafe {
+            if !self.d.is_null() {
+                (*self.d).bigendianp = value;
+            }
+        }
+    }
+    fn nsectors(&self) -> i64 {
+        self.nsectors
+    }
+    fn set_nsectors(&mut self, value: i64) {
+        self.nsectors = value;
+        unsafe {
+            if !self.d.is_null() {
+                (*self.d).nsectors = value as c_int;
+            }
+        }
+    }
+    fn interface(&self) -> InterfaceKind {
+        self.interface
+    }
+}
+
+unsafe fn p_ref<'a>(p: *mut c_void) -> Option<&'a mut Paranoia> {
+    if p.is_null() {
+        None
+    } else {
+        Some(&mut *(p as *mut Paranoia))
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn paranoia_version() -> *const c_char {
+    c"10.2".as_ptr()
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn paranoia_init(d: *mut CdromDrive) -> *mut c_void {
+    if d.is_null() {
+        return ptr::null_mut();
+    }
+    let mut adapter = CAbiDrive::new(d);
+    adapter.refresh();
+    let p = Paranoia::new(Box::new(adapter));
+    Box::into_raw(Box::new(p)) as *mut c_void
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn paranoia_free(p: *mut c_void) {
+    if !p.is_null() {
+        drop(Box::from_raw(p as *mut Paranoia));
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn paranoia_modeset(p: *mut c_void, mode: c_int) {
+    if let Some(p) = p_ref(p) {
+        p.modeset(mode);
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn paranoia_seek(p: *mut c_void, seek: c_long, mode: c_int) -> c_long {
+    match p_ref(p) {
+        Some(p) => p.seek(seek as i64, mode) as c_long,
+        None => -1,
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn paranoia_overlapset(p: *mut c_void, overlap: c_long) {
+    if let Some(p) = p_ref(p) {
+        p.overlapset(overlap as i64);
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn paranoia_cachemodel_size(p: *mut c_void, sectors: c_int) -> c_int {
+    match p_ref(p) {
+        Some(p) => p.cachemodel_size(sectors as i64) as c_int,
+        None => 0,
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn paranoia_read(p: *mut c_void, callback: ParanoiaCallback) -> *mut i16 {
+    paranoia_read_limited(p, callback, 20)
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn paranoia_read_limited(
+    p: *mut c_void,
+    callback: ParanoiaCallback,
+    max_retries: c_int,
+) -> *mut i16 {
+    let p = match p_ref(p) {
+        Some(p) => p,
+        None => return ptr::null_mut(),
+    };
+    let mut cb = |pos: i64, func: i32| {
+        if let Some(f) = callback {
+            f(pos as c_long, func as c_int);
+        }
+    };
+    match p.read_limited(&mut cb, max_retries) {
+        Some(slice) => slice.as_mut_ptr(),
+        None => {
+            let errno = if p.drive().opened() {
+                libc::EIO
+            } else {
+                libc::EBADF
+            };
+            *libc::__errno_location() = errno;
+            ptr::null_mut()
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use cdrustanoia_core::device::image::ImageDrive;
+    use cdrustanoia_core::device::samples_to_bytes;
+    use cdrustanoia_core::device::CD_FRAMEWORDS;
+
+    #[test]
+    fn c_api_query_and_read() {
+        unsafe {
+            let mut samples = Vec::new();
+            for i in 0..(3 * 1176) {
+                samples.push(((i * 37) as i16).wrapping_mul(3));
+            }
+            let bytes = samples_to_bytes(&samples);
+            let img = ImageDrive::from_bytes(bytes);
+            let d = cdda_interface::make_drive("test", None, Box::new(img));
+            assert_eq!(cdda_interface::cdda_open(d), 0);
+            assert_eq!(cdda_interface::cdda_tracks(d), 1);
+            assert_eq!(cdda_interface::cdda_disc_firstsector(d), 0);
+            assert_eq!(cdda_interface::cdda_disc_lastsector(d), 2);
+
+            let mut raw = vec![0u8; CD_FRAMESIZE_RAW];
+            let n = cdda_interface::cdda_read(d, raw.as_mut_ptr() as *mut c_void, 0, 1);
+            assert_eq!(n, 1);
+            assert_eq!(raw, samples_to_bytes(&samples[..1176]));
+
+            let p = paranoia_init(d);
+            assert!(!p.is_null());
+            paranoia_modeset(p, cdrustanoia_core::paranoia::PARANOIA_MODE_FULL);
+            paranoia_seek(p, 0, 0);
+            for sector in 0..3 {
+                let ptr = paranoia_read(p, None);
+                assert!(!ptr.is_null());
+                let got = std::slice::from_raw_parts(ptr, CD_FRAMEWORDS as usize);
+                assert_eq!(got, &samples[sector * 1176..(sector + 1) * 1176]);
+            }
+            paranoia_free(p);
+            cdda_interface::cdda_close(d);
+        }
+    }
+}