use std::ffi::{CStr, CString};
use std::str;
use chemfiles_sys::chfl_status;
use errors::check;
use Result;
pub fn from_c(buffer: *const i8) -> String {
let mut res = String::new();
unsafe {
let c_string = CStr::from_ptr(buffer);
let rust_str = str::from_utf8(c_string.to_bytes()).expect("invalid Rust string from C");
res.push_str(rust_str);
}
return res;
}
pub fn to_c(string: &str) -> CString {
CString::new(string).expect("Invalid C string from Rust")
}
fn buffer_was_big_enough(buffer: &[i8]) -> bool {
let len = buffer.len();
if len < 2 {
false
} else {
debug_assert_eq!(buffer[len - 1], 0);
buffer[len - 2] == 0
}
}
pub fn call_autogrow_buffer<F>(initial: usize, callback: F) -> Result<Vec<i8>>
where
F: Fn(*mut i8, u64) -> chfl_status,
{
let mut size = initial;
let mut buffer = vec![0; size];
try!(check(callback(buffer.as_mut_ptr(), buffer.len() as u64)));
while !buffer_was_big_enough(&buffer) {
size *= 2;
buffer.resize(size, 0);
try!(check(callback(buffer.as_mut_ptr(), buffer.len() as u64)));
}
Ok(buffer)
}