use builtin_macros::builtins;
use genawaiter::rc::Gen;
use std::{
env,
time::{SystemTime, UNIX_EPOCH},
};
use crate::{
self as tvix_eval,
errors::ErrorKind,
value::NixAttrs,
vm::generators::{self, GenCo},
NixString, Value,
};
#[builtins]
mod impure_builtins {
use std::ffi::OsStr;
use std::os::unix::ffi::OsStrExt;
use super::*;
use crate::builtins::{coerce_value_to_path, hash::hash_nix_string};
#[builtin("getEnv")]
async fn builtin_get_env(co: GenCo, var: Value) -> Result<Value, ErrorKind> {
Ok(env::var(OsStr::from_bytes(&var.to_str()?))
.unwrap_or_else(|_| "".into())
.into())
}
#[builtin("hashFile")]
async fn builtin_hash_file(co: GenCo, algo: Value, path: Value) -> Result<Value, ErrorKind> {
let path = match coerce_value_to_path(&co, path).await? {
Err(cek) => return Ok(Value::from(cek)),
Ok(p) => p,
};
let r = generators::request_open_file(&co, path).await;
hash_nix_string(algo.to_str()?, r).map(Value::from)
}
#[builtin("pathExists")]
async fn builtin_path_exists(co: GenCo, path: Value) -> Result<Value, ErrorKind> {
match coerce_value_to_path(&co, path).await? {
Err(cek) => Ok(Value::from(cek)),
Ok(path) => Ok(generators::request_path_exists(&co, path).await),
}
}
#[builtin("readDir")]
async fn builtin_read_dir(co: GenCo, path: Value) -> Result<Value, ErrorKind> {
match coerce_value_to_path(&co, path).await? {
Err(cek) => Ok(Value::from(cek)),
Ok(path) => {
let dir = generators::request_read_dir(&co, path).await;
let res = dir.into_iter().map(|(name, ftype)| {
(
// TODO: propagate Vec<u8> or bytes::Bytes into NixString.
NixString::from(
String::from_utf8(name.to_vec()).expect("parsing file name as string"),
),
Value::from(ftype.to_string()),
)
});
Ok(Value::attrs(NixAttrs::from_iter(res)))
}
}
}
#[builtin("readFile")]
async fn builtin_read_file(co: GenCo, path: Value) -> Result<Value, ErrorKind> {
match coerce_value_to_path(&co, path).await? {
Err(cek) => Ok(Value::from(cek)),
Ok(path) => {
let mut buf = Vec::new();
generators::request_open_file(&co, path)
.await
.read_to_end(&mut buf)?;
Ok(Value::from(buf))
}
}
}
#[builtin("readFileType")]
async fn builtin_read_file_type(co: GenCo, path: Value) -> Result<Value, ErrorKind> {
match coerce_value_to_path(&co, path).await? {
Err(cek) => Ok(Value::from(cek)),
Ok(path) => Ok(Value::from(
generators::request_read_file_type(&co, path)
.await
.to_string(),
)),
}
}
}
/// Return all impure builtins, that is all builtins which may perform I/O
/// outside of the VM and so cannot be used in all contexts (e.g. WASM).
pub fn impure_builtins() -> Vec<(&'static str, Value)> {
let mut result = impure_builtins::builtins();
// currentTime pins the time at which evaluation was started
{
let seconds = match SystemTime::now().duration_since(UNIX_EPOCH) {
Ok(dur) => dur.as_secs() as i64,
// This case is hit if the system time is *before* epoch.
Err(err) => -(err.duration().as_secs() as i64),
};
result.push(("currentTime", Value::Integer(seconds)));
}
result
}