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use crate::component::*;
use crate::{ExportKind, Module, RawSection, ValType};
use std::mem;
/// Convenience type to build a component incrementally and automatically keep
/// track of index spaces.
///
/// This type is intended to be a wrapper around the [`Component`] encoding type
/// which is useful for building it up incrementally over time. This type will
/// automatically collect definitions into sections and reports the index of all
/// items added by keeping track of indices internally.
#[derive(Debug, Default)]
pub struct ComponentBuilder {
/// The binary component that's being built.
component: Component,
/// The last section which was appended to during encoding. This type is
/// generated by the `section_accessors` macro below.
///
/// When something is encoded this is used if it matches the kind of item
/// being encoded, otherwise it's "flushed" to the output component and a
/// new section is started.
last_section: LastSection,
// Core index spaces
core_modules: u32,
core_funcs: u32,
core_types: u32,
core_memories: u32,
core_tables: u32,
core_instances: u32,
core_tags: u32,
core_globals: u32,
// Component index spaces
funcs: u32,
instances: u32,
types: u32,
components: u32,
values: u32,
}
impl ComponentBuilder {
/// Returns the current number of core modules.
pub fn core_module_count(&self) -> u32 {
self.core_modules
}
/// Returns the current number of core funcs.
pub fn core_func_count(&self) -> u32 {
self.core_funcs
}
/// Returns the current number of core types.
pub fn core_type_count(&self) -> u32 {
self.core_types
}
/// Returns the current number of core memories.
pub fn core_memory_count(&self) -> u32 {
self.core_memories
}
/// Returns the current number of core tables.
pub fn core_table_count(&self) -> u32 {
self.core_tables
}
/// Returns the current number of core instances.
pub fn core_instance_count(&self) -> u32 {
self.core_instances
}
/// Returns the current number of core tags.
pub fn core_tag_count(&self) -> u32 {
self.core_tags
}
/// Returns the current number of core globals.
pub fn core_global_count(&self) -> u32 {
self.core_globals
}
/// Returns the current number of component funcs.
pub fn func_count(&self) -> u32 {
self.funcs
}
/// Returns the current number of component instances.
pub fn instance_count(&self) -> u32 {
self.instances
}
/// Returns the current number of component values.
pub fn value_count(&self) -> u32 {
self.values
}
/// Returns the current number of components.
pub fn component_count(&self) -> u32 {
self.components
}
/// Returns the current number of component types.
pub fn type_count(&self) -> u32 {
self.types
}
/// Completes this component and returns the binary encoding of the entire
/// component.
pub fn finish(mut self) -> Vec<u8> {
self.flush();
self.component.finish()
}
/// Encodes a core wasm `Module` into this component, returning its index.
pub fn core_module(&mut self, module: &Module) -> u32 {
self.flush();
self.component.section(&ModuleSection(module));
inc(&mut self.core_modules)
}
/// Encodes a core wasm `module` into this component, returning its index.
pub fn core_module_raw(&mut self, module: &[u8]) -> u32 {
self.flush();
self.component.section(&RawSection {
id: ComponentSectionId::CoreModule.into(),
data: module,
});
inc(&mut self.core_modules)
}
/// Instantiates a core wasm module at `module_index` with the `args`
/// provided.
///
/// Returns the index of the core wasm instance crated.
pub fn core_instantiate<'a, A>(&mut self, module_index: u32, args: A) -> u32
where
A: IntoIterator<Item = (&'a str, ModuleArg)>,
A::IntoIter: ExactSizeIterator,
{
self.instances().instantiate(module_index, args);
inc(&mut self.core_instances)
}
/// Creates a new core wasm instance from the `exports` provided.
///
/// Returns the index of the core wasm instance crated.
pub fn core_instantiate_exports<'a, E>(&mut self, exports: E) -> u32
where
E: IntoIterator<Item = (&'a str, ExportKind, u32)>,
E::IntoIter: ExactSizeIterator,
{
self.instances().export_items(exports);
inc(&mut self.core_instances)
}
/// Creates a new aliased item where the core `instance` specified has its
/// export `name` aliased out with the `kind` specified.
///
/// Returns the index of the item crated.
pub fn core_alias_export(&mut self, instance: u32, name: &str, kind: ExportKind) -> u32 {
self.alias(Alias::CoreInstanceExport {
instance,
kind,
name,
})
}
/// Adds a new alias to this component
pub fn alias(&mut self, alias: Alias<'_>) -> u32 {
self.aliases().alias(alias);
match alias {
Alias::InstanceExport { kind, .. } => self.inc_kind(kind),
Alias::CoreInstanceExport { kind, .. } => self.inc_core_kind(kind),
Alias::Outer {
kind: ComponentOuterAliasKind::Type,
..
} => inc(&mut self.types),
Alias::Outer {
kind: ComponentOuterAliasKind::CoreModule,
..
} => inc(&mut self.core_modules),
Alias::Outer {
kind: ComponentOuterAliasKind::Component,
..
} => inc(&mut self.components),
Alias::Outer {
kind: ComponentOuterAliasKind::CoreType,
..
} => inc(&mut self.core_types),
}
}
/// Creates an alias to a previous component instance's exported item.
///
/// The `instance` provided is the instance to access and the `name` is the
/// item to access.
///
/// Returns the index of the new item defined.
pub fn alias_export(&mut self, instance: u32, name: &str, kind: ComponentExportKind) -> u32 {
self.alias(Alias::InstanceExport {
instance,
kind,
name,
})
}
fn inc_kind(&mut self, kind: ComponentExportKind) -> u32 {
match kind {
ComponentExportKind::Func => inc(&mut self.funcs),
ComponentExportKind::Module => inc(&mut self.core_modules),
ComponentExportKind::Type => inc(&mut self.types),
ComponentExportKind::Component => inc(&mut self.components),
ComponentExportKind::Instance => inc(&mut self.instances),
ComponentExportKind::Value => inc(&mut self.values),
}
}
fn inc_core_kind(&mut self, kind: ExportKind) -> u32 {
match kind {
ExportKind::Func => inc(&mut self.core_funcs),
ExportKind::Table => inc(&mut self.core_tables),
ExportKind::Memory => inc(&mut self.core_memories),
ExportKind::Global => inc(&mut self.core_globals),
ExportKind::Tag => inc(&mut self.core_tags),
}
}
/// Lowers the `func_index` component function into a core wasm function
/// using the `options` provided.
///
/// Returns the index of the core wasm function created.
pub fn lower_func<O>(&mut self, func_index: u32, options: O) -> u32
where
O: IntoIterator<Item = CanonicalOption>,
O::IntoIter: ExactSizeIterator,
{
self.canonical_functions().lower(func_index, options);
inc(&mut self.core_funcs)
}
/// Lifts the core wasm `core_func_index` function with the component
/// function type `type_index` and `options`.
///
/// Returns the index of the component function created.
pub fn lift_func<O>(&mut self, core_func_index: u32, type_index: u32, options: O) -> u32
where
O: IntoIterator<Item = CanonicalOption>,
O::IntoIter: ExactSizeIterator,
{
self.canonical_functions()
.lift(core_func_index, type_index, options);
inc(&mut self.funcs)
}
/// Imports a new item into this component with the `name` and `ty` specified.
pub fn import(&mut self, name: &str, ty: ComponentTypeRef) -> u32 {
let ret = match &ty {
ComponentTypeRef::Instance(_) => inc(&mut self.instances),
ComponentTypeRef::Func(_) => inc(&mut self.funcs),
ComponentTypeRef::Type(..) => inc(&mut self.types),
ComponentTypeRef::Component(_) => inc(&mut self.components),
ComponentTypeRef::Module(_) => inc(&mut self.core_modules),
ComponentTypeRef::Value(_) => inc(&mut self.values),
};
self.imports().import(name, ty);
ret
}
/// Exports a new item from this component with the `name` and `kind`
/// specified.
///
/// The `idx` is the item to export and the `ty` is an optional type to
/// ascribe to the export.
pub fn export(
&mut self,
name: &str,
kind: ComponentExportKind,
idx: u32,
ty: Option<ComponentTypeRef>,
) -> u32 {
self.exports().export(name, kind, idx, ty);
self.inc_kind(kind)
}
/// Creates a new encoder for the next core type in this component.
pub fn core_type(&mut self) -> (u32, CoreTypeEncoder<'_>) {
(inc(&mut self.core_types), self.core_types().ty())
}
/// Creates a new encoder for the next type in this component.
pub fn ty(&mut self) -> (u32, ComponentTypeEncoder<'_>) {
(inc(&mut self.types), self.types().ty())
}
/// Creates a new instance type within this component.
pub fn type_instance(&mut self, ty: &InstanceType) -> u32 {
self.types().instance(ty);
inc(&mut self.types)
}
/// Creates a new component type within this component.
pub fn type_component(&mut self, ty: &ComponentType) -> u32 {
self.types().component(ty);
inc(&mut self.types)
}
/// Creates a new defined component type within this component.
pub fn type_defined(&mut self) -> (u32, ComponentDefinedTypeEncoder<'_>) {
(inc(&mut self.types), self.types().defined_type())
}
/// Creates a new component function type within this component.
pub fn type_function(&mut self) -> (u32, ComponentFuncTypeEncoder<'_>) {
(inc(&mut self.types), self.types().function())
}
/// Declares a
pub fn type_resource(&mut self, rep: ValType, dtor: Option<u32>) -> u32 {
self.types().resource(rep, dtor);
inc(&mut self.types)
}
/// Defines a new subcomponent of this component.
pub fn component(&mut self, mut builder: ComponentBuilder) -> u32 {
builder.flush();
self.flush();
self.component
.section(&NestedComponentSection(&builder.component));
inc(&mut self.components)
}
/// Defines a new subcomponent of this component.
pub fn component_raw(&mut self, data: &[u8]) -> u32 {
let raw_section = RawSection {
id: ComponentSectionId::Component.into(),
data,
};
self.flush();
self.component.section(&raw_section);
inc(&mut self.components)
}
/// Instantiates the `component_index` specified with the `args` specified.
pub fn instantiate<A, S>(&mut self, component_index: u32, args: A) -> u32
where
A: IntoIterator<Item = (S, ComponentExportKind, u32)>,
A::IntoIter: ExactSizeIterator,
S: AsRef<str>,
{
self.component_instances()
.instantiate(component_index, args);
inc(&mut self.instances)
}
/// Declares a new `resource.drop` intrinsic.
pub fn resource_drop(&mut self, ty: u32) -> u32 {
self.canonical_functions().resource_drop(ty);
inc(&mut self.core_funcs)
}
/// Declares a new `resource.new` intrinsic.
pub fn resource_new(&mut self, ty: u32) -> u32 {
self.canonical_functions().resource_new(ty);
inc(&mut self.core_funcs)
}
/// Declares a new `resource.rep` intrinsic.
pub fn resource_rep(&mut self, ty: u32) -> u32 {
self.canonical_functions().resource_rep(ty);
inc(&mut self.core_funcs)
}
/// Adds a new custom section to this component.
pub fn custom_section(&mut self, section: &CustomSection<'_>) {
self.flush();
self.component.section(section);
}
/// Adds a new custom section to this component.
pub fn raw_custom_section(&mut self, section: &[u8]) {
self.flush();
self.component.section(&RawCustomSection(section));
}
}
// Helper macro to generate methods on `ComponentBuilder` to get specific
// section encoders that automatically flush and write out prior sections as
// necessary.
macro_rules! section_accessors {
($($method:ident => $section:ident)*) => (
#[derive(Debug, Default)]
enum LastSection {
#[default]
None,
$($section($section),)*
}
impl ComponentBuilder {
$(
fn $method(&mut self) -> &mut $section {
match &self.last_section {
// The last encoded section matches the section that's
// being requested, so no change is necessary.
LastSection::$section(_) => {}
// Otherwise the last section didn't match this section,
// so flush any prior section if needed and start
// encoding the desired section of this method.
_ => {
self.flush();
self.last_section = LastSection::$section($section::new());
}
}
match &mut self.last_section {
LastSection::$section(ret) => ret,
_ => unreachable!()
}
}
)*
/// Writes out the last section into the final component binary if
/// there is a section specified, otherwise does nothing.
fn flush(&mut self) {
match mem::take(&mut self.last_section) {
LastSection::None => {}
$(
LastSection::$section(section) => {
self.component.section(§ion);
}
)*
}
}
}
)
}
section_accessors! {
component_instances => ComponentInstanceSection
instances => InstanceSection
canonical_functions => CanonicalFunctionSection
aliases => ComponentAliasSection
exports => ComponentExportSection
imports => ComponentImportSection
types => ComponentTypeSection
core_types => CoreTypeSection
}
fn inc(idx: &mut u32) -> u32 {
let ret = *idx;
*idx += 1;
ret
}