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Diffstat (limited to 'tvix/eval/src/builtins/impure.rs')
-rw-r--r-- | tvix/eval/src/builtins/impure.rs | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/tvix/eval/src/builtins/impure.rs b/tvix/eval/src/builtins/impure.rs new file mode 100644 index 0000000000..c82b910f5f --- /dev/null +++ b/tvix/eval/src/builtins/impure.rs @@ -0,0 +1,110 @@ +use builtin_macros::builtins; +use genawaiter::rc::Gen; + +use std::{ + env, + time::{SystemTime, UNIX_EPOCH}, +}; + +use crate::{ + self as tvix_eval, + errors::ErrorKind, + io::FileType, + 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(match ftype { + FileType::Directory => "directory", + FileType::Regular => "regular", + FileType::Symlink => "symlink", + FileType::Unknown => "unknown", + }), + ) + }); + + 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)) + } + } + } +} + +/// 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 +} |