Add write and delete FK table objects

Author: Radonirinaunimi

pineappl_capi/cbindgen.toml

@@ -48,7 +48,7 @@ rename_variants = "ScreamingSnakeCase"
 "KeyVal" = "pineappl_keyval"
 "SubGrid" = "pineappl_subgrid"
 "GridOptFlags" = "pineappl_gof"
-"OperatorSliceInfo" = "pineappl_operator_slice_info"
+"OperatorInfo" = "pineappl_operator_info"
 
 ############## Options for How Your Rust library Should Be Parsed ##############
 

pineappl_capi/src/lib.rs

@@ -2096,7 +2096,7 @@ pub unsafe extern "C" fn pineappl_grid_evolve_info(
     ren1.copy_from_slice(&grid.evolve_info(&order_mask).ren1);
 }
 
-/// Evolve a grid and dump the resulting FK table
+/// Evolve a grid and dump the resulting FK table.
 ///
 /// # Safety
 ///
@@ -2202,3 +2202,35 @@ pub unsafe extern "C" fn pineappl_grid_evolve(
 
     Box::new(fk_table.unwrap())
 }
+
+/// Delete an FK table.
+#[no_mangle]
+#[allow(unused_variables)]
+pub extern "C" fn pineappl_fk_table_delete(fktable: Option<Box<FkTable>>) {}
+
+/// Write `fktable` to a file with name `filename`. If `filename` ends in `.lz4` the Fk table is
+/// automatically LZ4 compressed.
+///
+/// # Safety
+///
+/// If `fktable` does not point to a valid `FkTable` object, for example when `fktable` is a null
+/// pointer, this function is not safe to call. The parameter `filename` must be a non-`NULL`,
+/// non-empty, and valid C string pointing to a non-existing, but writable file.
+///
+/// # Panics
+///
+/// TODO
+#[no_mangle]
+pub unsafe extern "C" fn pineappl_fktable_write(fktable: *const FkTable, filename: *const c_char) {
+    let fktable = unsafe { &*fktable };
+    let filename = unsafe { CStr::from_ptr(filename) };
+    let filename = filename.to_string_lossy();
+    let path = Path::new(filename.as_ref());
+    let writer = File::create(path).unwrap();
+
+    if path.extension().is_some_and(|ext| ext == "lz4") {
+        fktable.grid().write_lz4(writer).unwrap();
+    } else {
+        fktable.grid().write(writer).unwrap();
+    }
+}