Enum wasmtime_environ::TableInitialization

pub enum TableInitialization {
    Segments {
        segments: Vec<TableInitializer>,
    },
    FuncTable {
        tables: PrimaryMap<TableIndex, Vec<FuncIndex>>,
        segments: Vec<TableInitializer>,
    },
}

Table initialization data for all tables in the module.

Variants

Segments

Fields

segments: Vec<TableInitializer>

The segment initializers. All apply to the table for which this TableInitialization is specified.

“Segment” mode: table initializer segments, possibly with dynamic bases, possibly applying to an imported memory.

Every kind of table initialization is supported by the Segments mode.

FuncTable

Fields

tables: PrimaryMap<TableIndex, Vec<FuncIndex>>

For each table, an array of function indices (or FuncIndex::reserved_value(), meaning no initialized value, hence null by default). Array elements correspond one-to-one to table elements; i.e., elements[i] is the initial value for table[i].

segments: Vec<TableInitializer>

Leftover segments that need to be processed eagerly on instantiation. These either apply to an imported table (so we can’t pre-build a full image of the table from this overlay) or have dynamically (at instantiation time) determined bases.

“FuncTable” mode: a single array per table, with a function index or null per slot. This is only possible to provide for a given table when it is defined by the module itself, and can only include data from initializer segments that have statically-knowable bases (i.e., not dependent on global values).

Any segments that are not compatible with this mode are held in the segments array of “leftover segments”, which are still processed eagerly.

This mode facilitates lazy initialization of the tables. It is thus “nice to have”, but not necessary for correctness.

Trait Implementations

impl Debug for TableInitialization

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for TableInitialization

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for TableInitialization

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for TableInitialization

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>where __S: Serializer,

Serialize this value into the given Serde serializer.