Trait soroban_env_host::EnvBase

pub trait EnvBase: Sized + Clone {
    type Error: Debug + Into<Error> + From<Error>;

    // Required methods
    fn escalate_error_to_panic(&self, e: Self::Error) -> !;
    fn as_mut_any(&mut self) -> &mut (dyn Any + 'static);
    fn check_same_env(&self, other: &Self);
    fn deep_clone(&self) -> Self;
    fn bytes_copy_from_slice(
        &self,
        b: BytesObject,
        b_pos: U32Val,
        slice: &[u8]
    ) -> Result<BytesObject, Self::Error>;
    fn bytes_copy_to_slice(
        &self,
        b: BytesObject,
        b_pos: U32Val,
        slice: &mut [u8]
    ) -> Result<(), Self::Error>;
    fn string_copy_to_slice(
        &self,
        b: StringObject,
        b_pos: U32Val,
        slice: &mut [u8]
    ) -> Result<(), Self::Error>;
    fn symbol_copy_to_slice(
        &self,
        b: SymbolObject,
        b_pos: U32Val,
        mem: &mut [u8]
    ) -> Result<(), Self::Error>;
    fn bytes_new_from_slice(
        &self,
        slice: &[u8]
    ) -> Result<BytesObject, Self::Error>;
    fn string_new_from_slice(
        &self,
        slice: &str
    ) -> Result<StringObject, Self::Error>;
    fn symbol_new_from_slice(
        &self,
        slice: &str
    ) -> Result<SymbolObject, Self::Error>;
    fn map_new_from_slices(
        &self,
        keys: &[&str],
        vals: &[Val]
    ) -> Result<MapObject, Self::Error>;
    fn map_unpack_to_slice(
        &self,
        map: MapObject,
        keys: &[&str],
        vals: &mut [Val]
    ) -> Result<Void, Self::Error>;
    fn vec_new_from_slice(&self, vals: &[Val]) -> Result<VecObject, Self::Error>;
    fn vec_unpack_to_slice(
        &self,
        vec: VecObject,
        vals: &mut [Val]
    ) -> Result<Void, Self::Error>;
    fn symbol_index_in_strs(
        &self,
        key: Symbol,
        strs: &[&str]
    ) -> Result<U32Val, Self::Error>;
    fn log_from_slice(
        &self,
        msg: &str,
        vals: &[Val]
    ) -> Result<Void, Self::Error>;

    // Provided method
    fn augment_err_result<T>(
        &self,
        x: Result<T, Self::Error>
    ) -> Result<T, Self::Error> { ... }
}

Base trait extended by the Env trait, providing various special-case functions that do not simply call across cross the guest/host interface.

Required Associated Types

type Error: Debug + Into<Error> + From<Error>

The type of error returned from the environment when the environment itself fails “unrecoverably”, or at least in a way that the user is not expected to be able to recover from, such as an internal logic error, exceeding the execution budget, or being passed malformed input in a way that the user-facing API does not anticipate or allow for. This type is returned from all environment-interface methods, and will only ever take on two possible concrete types: either Infallible (in the Guest) or HostError (in the Host).

The Guest can treat all such errors as impossible-to-observe since they will result in the Host trapping the Guest before returning an Error to it. Such errors still remain present in the Env API so that we can use the same API in both scenarios, rather than having to have separate “fallible” or “infallible” environments and separate conversion routines for each (as was attempted in earlier iterations).

This type is not the same as an error intended to make it to the user-facing API: user-facing errors should return Ok(Error) at the environment-interface level, and then either directly handle or escalate the contained Error code to the user as a Error or Result<> of some other type, depending on the API.

Required Methods

fn escalate_error_to_panic(&self, e: Self::Error) -> !

Reject an error from the environment, turning it into a panic but on terms that the environment controls (eg. transforming or logging it). This should only ever be called by client-side / SDK local-testing code, never in the Host.

fn as_mut_any(&mut self) -> &mut (dyn Any + 'static)

Used for recovering the concrete type of the Host.

fn check_same_env(&self, other: &Self)

Used to check two environments are the same, trapping if not.

fn deep_clone(&self) -> Self

Used to clone an environment deeply, not just a handle to it.

fn bytes_copy_from_slice( &self, b: BytesObject, b_pos: U32Val, slice: &[u8] ) -> Result<BytesObject, Self::Error>

Clone an existing Bytes object in the host, replacing the portion of its memory with bytes supplied by slice, returning the new object. The replaced portion of the original object’s memory begins at b_pos and extends for the same length as the new slice.

fn bytes_copy_to_slice( &self, b: BytesObject, b_pos: U32Val, slice: &mut [u8] ) -> Result<(), Self::Error>

Copy a slice of bytes from a Bytes object in the host into a slice in the caller’s memory.

fn string_copy_to_slice( &self, b: StringObject, b_pos: U32Val, slice: &mut [u8] ) -> Result<(), Self::Error>

Copy a slice of bytes from a String object in the host into a slice in the caller’s memory.

fn symbol_copy_to_slice( &self, b: SymbolObject, b_pos: U32Val, mem: &mut [u8] ) -> Result<(), Self::Error>

Copy a slice of bytes from a Symbol object in the host into the caller’s memory.

fn bytes_new_from_slice(&self, slice: &[u8]) -> Result<BytesObject, Self::Error>

Form a new Bytes host object from a slice of client memory.

fn string_new_from_slice( &self, slice: &str ) -> Result<StringObject, Self::Error>

Form a new String host object from a slice of client memory.

fn symbol_new_from_slice( &self, slice: &str ) -> Result<SymbolObject, Self::Error>

Form a new Symbol host object from a slice of client memory.

fn map_new_from_slices( &self, keys: &[&str], vals: &[Val] ) -> Result<MapObject, Self::Error>

Form a new Map host object from a slice of symbol-names and a slice of values. Keys must be in sorted order.

fn map_unpack_to_slice( &self, map: MapObject, keys: &[&str], vals: &mut [Val] ) -> Result<Void, Self::Error>

Unpack a Map host object with a specified set of keys to a slice of Vals. Keys must be in sorted order and must match the key set of the unpacked object exactly.

fn vec_new_from_slice(&self, vals: &[Val]) -> Result<VecObject, Self::Error>

Form a new Vec host object from a slice of values.

fn vec_unpack_to_slice( &self, vec: VecObject, vals: &mut [Val] ) -> Result<Void, Self::Error>

Form a new Vec host object from a slice of values. The values slice must be the same length as the host object.

fn symbol_index_in_strs( &self, key: Symbol, strs: &[&str] ) -> Result<U32Val, Self::Error>

Return the index of a Symbol in an array of &strs, or error if not found.

fn log_from_slice(&self, msg: &str, vals: &[Val]) -> Result<Void, Self::Error>

Log a string and set of values as a diagnostic event, if diagnostic events are enabled. When running on host, logs directly; when running on guest, redirects through log_from_linear_memory.

Provided Methods

fn augment_err_result<T>( &self, x: Result<T, Self::Error> ) -> Result<T, Self::Error>

If x is Err(...), ensure as much debug information as possible is attached to that error; in any case return “essentially the same” x – either Ok(...) or Err(...) – just with extra error context.

This is called on a best-effort basis while propagating errors in the host, to attach context “as soon as possible”, and is necessary because some errors are generated in contexts that do not have access to a Host, and so cannot attach error context at the site of error generation.

Implementors

impl EnvBase for Host

type Error = HostError

impl EnvBase for UnimplementedEnv

type Error = Infallible