Module holochain_wasmer_host::prelude

Re-exports

• pub use crate::env::Env;
• pub use crate::guest;

Modules

• result
• serde_bytes
  Wrapper types to enable optimized handling of &[u8] and Vec<u8>.

Macros

• holochain_serial
  unidiomatic way to derive default trait implementations of TryFrom in/out of SerializedBytes
• wasm_error
  Helper macro for returning an error from a WASM.

Structs

• SerializedBytes
  A Canonical Serialized Bytes representation for data If you have a data structure that needs a canonical byte representation use this Always round-trip through SerializedBytes via. a single TryFrom implementation. This ensures that the internal bytes of SerializedBytes are indeed canonical. The corrolary is that if bytes are NOT wrapped in SerializedBytes we can assume they are NOT canonical. Typically we need a canonical serialization when data is to be handled at the byte level by independently implemented and maintained systems.
• UnsafeBytes
  UnsafeBytes the only way to implement a custom round trip through bytes for SerializedBytes It is intended to be an internal implementation in TryFrom implementations The assumption is that any code using UnsafeBytes is NOT valid messagepack data This allows us to enforce that all data round-tripping through SerializedBytes is via TryFrom and also allow for custom non-messagepack canonical representations of data types.
• WasmError
  Wraps a WasmErrorInner with a file and line number. The easiest way to generate this is with the wasm_error! macro that will insert the correct file/line and can create strings by forwarding args to the format! macro.

Enums

• SerializedBytesError
• WasmErrorInner
  Enum of all possible ERROR states that wasm can encounter.

Traits

• Deserialize
  A data structure that can be deserialized from any data format supported by Serde.
• Serialize
  A data structure that can be serialized into any data format supported by Serde.
• TryFrom
  Simple and safe type conversions that may fail in a controlled way under some circumstances. It is the reciprocal of TryInto.
• TryInto
  An attempted conversion that consumes self, which may or may not be expensive.

Functions

• decode
• encode
• merge_u32
• merge_u64
• merge_usize
  Given 2x u32, return a DoubleUSize merged. Works via a simple bitwise shift to move the pointer to high bits then OR the length into the low bits.
• split_u64
• split_u128
• split_usize
  Given 2x merged usize, split out two usize. Performs the inverse of merge_usize.

Type Aliases

• DoubleUSize
• GuestPtr
  A WasmSize that points to a position in wasm linear memory that the host and guest are sharing to communicate across function calls.
• GuestPtrLen
  Enough bits to fit a pointer and length into so we can return it. The externs defined as “C” don’t support multiple return values (unlike wasm). The native Rust support for wasm externs is not stable at the time of writing.
• Len
  A WasmSize integer that represents the size of bytes to read/write to memory.
• Mutex
  A mutual exclusion primitive useful for protecting shared data
• WasmSize
  Something like usize for wasm. Wasm has a memory limit of 4GB so offsets and lengths fit in u32.

Derive Macros

• Deserialize
• Serialize
• SerializedBytes