feat: add FitsFile::file_path method to access FitsFile file path (…

…#367)

Include a method to access the file path of the `FitsFile`.

During my investigation I found that there was no reason to make it
optional. Given this, I have made the field/function return non-optional
as well.

Also: it is stored as a `PathBuf` internally, and inherently refers to a
path on disk, so let's return a `Path` in that case.

Closes #366

fitsio/src/fitsfile.rs

@@ -12,7 +12,7 @@ use crate::errors::{check_status, Error, Result};
 use crate::hdu::{DescribesHdu, FitsHdu, FitsHduIterator, HduInfo};
 use crate::images::{ImageDescription, ImageType};
 use crate::longnam::*;
-use crate::stringutils::{self, status_to_string};
+use crate::stringutils::{self, buf_to_string, status_to_string};
 use crate::tables::{ColumnDataDescription, ConcreteColumnDescription};
 use std::ffi;
 use std::io::{self, Write};
@@ -21,7 +21,7 @@ use std::ptr;
 
 /// Main entry point to the FITS file format
 pub struct FitsFile {
-    filename: Option<PathBuf>,
+    file_path: PathBuf,
     open_mode: FileOpenMode,
     pub(crate) fptr: ptr::NonNull<fitsfile>,
 }
@@ -64,7 +64,7 @@ impl FitsFile {
             Some(p) => FitsFile {
                 fptr: p,
                 open_mode: FileOpenMode::READONLY,
-                filename: Some(file_path.to_path_buf()),
+                file_path: file_path.to_path_buf(),
             },
             None => unimplemented!(),
         })
@@ -106,7 +106,7 @@ impl FitsFile {
             Some(p) => FitsFile {
                 fptr: p,
                 open_mode: FileOpenMode::READWRITE,
-                filename: Some(file_path.to_path_buf()),
+                file_path: file_path.to_path_buf(),
             },
             None => unimplemented!(),
         })
@@ -255,6 +255,11 @@ impl FitsFile {
         self.hdu(0)
     }
 
+    /// Return the file path of the file
+    pub fn file_path(&self) -> &Path {
+        &self.file_path
+    }
+
     /// Return the number of HDU objects in the file
     fn num_hdus(&mut self) -> Result<usize> {
         let mut status = 0;
@@ -650,9 +655,7 @@ impl FitsFile {
     where
         W: Write,
     {
-        if let Some(ref filename) = self.filename {
-            writeln!(w, "\n  file: {:?}", filename)?;
-        }
+        writeln!(w, "\n  file: {}", self.file_path.display())?;
         match self.open_mode {
             FileOpenMode::READONLY => writeln!(w, "  mode: READONLY")?,
             FileOpenMode::READWRITE => writeln!(w, "  mode: READWRITE")?,
@@ -783,8 +786,13 @@ impl FitsFile {
     /// # }
     /// ```
     pub unsafe fn from_raw(fptr: *mut fitsfile, mode: FileOpenMode) -> Result<FitsFile> {
+        let mut buf = vec![0; 1025];
+        let mut status = 0;
+        unsafe { fits_file_name(fptr, buf.as_mut_ptr(), &mut status) };
+        let s = buf_to_string(&buf)?;
+
         Ok(Self {
-            filename: None,
+            file_path: PathBuf::from(s),
             open_mode: mode,
             fptr: ptr::NonNull::new(fptr).ok_or(Error::NullPointer)?,
         })
@@ -905,7 +913,7 @@ where
                 Some(p) => FitsFile {
                     fptr: p,
                     open_mode: FileOpenMode::READWRITE,
-                    filename: Some(file_path.to_path_buf()),
+                    file_path: file_path.to_path_buf(),
                 },
                 None => unimplemented!(),
             };
@@ -1051,14 +1059,18 @@ casesensitivity_into_impl!(i64);
 
 #[cfg(test)]
 mod test {
+    use libc::c_int;
+
     use crate::errors::Error;
     use crate::fitsfile::FitsFile;
     use crate::fitsfile::{FileOpenMode, ImageDescription};
     use crate::hdu::{FitsHdu, HduInfo};
     use crate::images::ImageType;
     use crate::tables::{ColumnDataType, ColumnDescription};
     use crate::testhelpers::{duplicate_test_file, with_temp_file};
+    use std::ffi::CString;
     use std::path::Path;
+    use std::ptr;
 
     #[test]
     fn test_opening_an_existing_file() {
@@ -1610,4 +1622,38 @@ mod test {
             }
         });
     }
+
+    #[test]
+    fn test_get_filename() {
+        use crate::longnam::fits_open_file;
+        use fitsio_sys::fitsfile;
+
+        duplicate_test_file(|src_filename| {
+            let f = FitsFile::open(src_filename).unwrap();
+
+            // open file manually
+            let mut fptr: *mut fitsfile = ptr::null_mut();
+            let mut status = 0;
+            let c_filename = CString::new(src_filename).unwrap();
+            unsafe {
+                fits_open_file(
+                    &mut fptr as *mut *mut fitsfile,
+                    c_filename.as_ptr(),
+                    FileOpenMode::READONLY as c_int,
+                    &mut status,
+                )
+            };
+
+            if status != 0 {
+                panic!("error opening file manually");
+            }
+
+            assert!(!fptr.is_null());
+
+            let f2 = unsafe { FitsFile::from_raw(fptr, FileOpenMode::READONLY).unwrap() };
+
+            assert_eq!(f.file_path(), Path::new(src_filename));
+            assert_eq!(f2.file_path(), Path::new(src_filename));
+        });
+    }
 }

fitsio/src/longnam.rs

@@ -5,12 +5,12 @@
 #![allow(unused_imports, dead_code)]
 
 pub(crate) use crate::sys::{
-    ffclos, ffcopy, ffcrim, ffcrtb, ffdcol, ffdhdu, ffflmd, ffgbcl, ffgcdw, ffgcno, ffgcvb, ffgcvd,
-    ffgcve, ffgcvi, ffgcvj, ffgcvjj, ffgcvk, ffgcvl, ffgcvs, ffgcvsb, ffgcvui, ffgcvuj, ffgcvujj,
-    ffgcvuk, ffgcx, ffghdn, ffghdt, ffgidm, ffgiet, ffgisz, ffgkyd, ffgkye, ffgkyj, ffgkyjj,
-    ffgkyl, ffgkys, ffgncl, ffgnrw, ffgpv, ffgsv, fficol, ffinit, ffmahd, ffmnhd, ffopen, ffpcl,
-    ffpcls, ffpclx, ffphps, ffpky, ffpkyd, ffpkye, ffpkys, ffppr, ffpss, ffrsim, ffthdu, fitsfile,
-    LONGLONG,
+    ffclos, ffcopy, ffcrim, ffcrtb, ffdcol, ffdhdu, ffflmd, ffflnm, ffgbcl, ffgcdw, ffgcno, ffgcvb,
+    ffgcvd, ffgcve, ffgcvi, ffgcvj, ffgcvjj, ffgcvk, ffgcvl, ffgcvs, ffgcvsb, ffgcvui, ffgcvuj,
+    ffgcvujj, ffgcvuk, ffgcx, ffghdn, ffghdt, ffgidm, ffgiet, ffgisz, ffgkyd, ffgkye, ffgkyj,
+    ffgkyjj, ffgkyl, ffgkys, ffgncl, ffgnrw, ffgpv, ffgsv, fficol, ffinit, ffmahd, ffmnhd, ffopen,
+    ffpcl, ffpcls, ffpclx, ffphps, ffpky, ffpkyd, ffpkye, ffpkys, ffppr, ffpss, ffrsim, ffthdu,
+    fitsfile, LONGLONG,
 };
 pub use libc::{
     c_char, c_double, c_float, c_int, c_long, c_schar, c_short, c_uchar, c_uint, c_ulong,
@@ -650,3 +650,11 @@ pub(crate) unsafe fn fits_write_key(
 ) -> c_int {
     ffpky(fptr, datatype, keyname, value, comm, status)
 }
+
+pub(crate) unsafe fn fits_file_name(
+    fptr: *mut fitsfile,
+    filename: *mut c_char,
+    status: *mut c_int,
+) -> c_int {
+    ffflnm(fptr, filename, status)
+}