use fixed::Fixed;
use fnv::FnvHashMap;
use std::{slice, str};
#[repr(C)]
pub struct Context {
class: Fixed<ContextClass>,
config: FnvHashMap<String, String>,
}
impl Context {
pub fn new(config: FnvHashMap<String, String>) -> Context {
Self {
class: CONTEXT_CLASS.clone(),
config,
}
}
pub fn get_config(&self, key: &str) -> &str {
let mut len = key.len() as u64;
let data = (self.class.get_config)(self, key.as_ptr(), &mut len);
unsafe { str::from_utf8_unchecked(slice::from_raw_parts(data, len as usize)) }
}
}
#[repr(C)]
pub struct ContextClass {
get_config: extern "C" fn(*const Context, *const u8, *mut u64) -> *const u8,
}
impl ContextClass {
fn new() -> ContextClass {
Self {
get_config: abi_get_config,
}
}
}
extern "C" fn abi_get_config(ctx: *const Context, data: *const u8, len: *mut u64) -> *const u8 {
unsafe {
let key = str::from_utf8_unchecked(slice::from_raw_parts(data, *len as usize));
let val = (*ctx).config.get(key).map(|s| s.as_str()).unwrap_or("");
*len = val.len() as u64;
val.as_ptr()
}
}
lazy_static! {
static ref CONTEXT_CLASS: Fixed<ContextClass> = Fixed::new(ContextClass::new());
}