Skip to content

Commit

Permalink
feat: optimized host bindings (#382)
Browse files Browse the repository at this point in the history
  • Loading branch information
@guybedford
guybedford authored Mar 7, 2024
1 parent a23cc46 commit 9058965
Show file tree
Hide file tree
Showing 252 changed files with 1,087 additions and 246 deletions.
13 changes: 13 additions & 0 deletions crates/js-component-bindgen-component/src/lib.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -46,6 +46,17 @@ impl From<InstantiationMode> for js_component_bindgen::InstantiationMode {
}
}

impl From<BindingsMode> for js_component_bindgen::BindingsMode {
fn from(value: BindingsMode) -> Self {
match value {
BindingsMode::Js => js_component_bindgen::BindingsMode::Js,
BindingsMode::DirectOptimized => js_component_bindgen::BindingsMode::DirectOptimized,
BindingsMode::Optimized => js_component_bindgen::BindingsMode::Optimized,
BindingsMode::Hybrid => js_component_bindgen::BindingsMode::Hybrid,
}
}
}

struct JsComponentBindgenComponent;

export!(JsComponentBindgenComponent);
Expand All @@ -67,6 +78,7 @@ impl Guest for JsComponentBindgenComponent {
tracing: options.tracing.unwrap_or(false),
no_namespaced_exports: options.no_namespaced_exports.unwrap_or(false),
multi_memory: options.multi_memory.unwrap_or(false),
import_bindings: options.import_bindings.map(Into::into),
};

let js_component_bindgen::Transpiled {
Expand Down Expand Up @@ -134,6 +146,7 @@ impl Guest for JsComponentBindgenComponent {
tracing: false,
no_namespaced_exports: false,
multi_memory: false,
import_bindings: None,
};

let files = generate_types(name, resolve, world, opts).map_err(|e| e.to_string())?;
Expand Down
10 changes: 10 additions & 0 deletions crates/js-component-bindgen-component/wit/js-component-bindgen.wit
View file
Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,13 @@ world js-component-bindgen {
sync,
}

variant bindings-mode {
js,
hybrid,
optimized,
direct-optimized,
}

record generate-options {
/// Name to use for the generated component
name: string,
Expand All @@ -21,6 +28,9 @@ world js-component-bindgen {
/// of the direct importable native ESM output.
instantiation: option<instantiation-mode>,

/// Import bindings generation mode
import-bindings: option<bindings-mode>,

/// Mappings of component import specifiers to JS import specifiers.
map: option<maps>,

Expand Down
132 changes: 70 additions & 62 deletions crates/js-component-bindgen/src/function_bindgen.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -45,8 +45,9 @@ pub enum ResourceData {
///
/// For a given resource id {x}, the local variables are assumed:
/// - handleTable{x}
/// - captureTable{x} (only for imported tables)
/// - captureCnt{x} (only for imported tables)
/// - captureTable{x} (rep to instance map for captured imported tables, only for JS import bindgen,
/// not hybrid)
/// - captureCnt{x} for assigning capture rep
///
/// For component-defined resources:
/// - finalizationRegistry{x}
Expand Down Expand Up @@ -1045,17 +1046,6 @@ impl Bindgen for FunctionBindgen<'_> {
self.bind_results(sig_results_length, results);
uwriteln!(self.src, "{}({});", self.callee, operands.join(", "));

if !self.cur_resource_borrows.is_empty() {
uwriteln!(
self.src,
"if ({}) {{
throw new Error('Resource error: borrows were not dropped');
}}",
self.cur_resource_borrows.join(" || ")
);
self.cur_resource_borrows = Vec::new();
}

if let Some(prefix) = self.tracing_prefix {
let to_result_string = self.intrinsic(Intrinsic::ToResultString);
uwriteln!(
Expand Down Expand Up @@ -1196,16 +1186,16 @@ impl Bindgen for FunctionBindgen<'_> {
let id = id.as_u32();
let symbol_dispose = self.intrinsic(Intrinsic::SymbolDispose);
let rsc_table_remove = self.intrinsic(Intrinsic::ResourceTableRemove);
let rep = format!("rep{}", self.tmp());
if !imported {
let rep = format!("rep{}", self.tmp());
let symbol_resource_handle =
self.intrinsic(Intrinsic::SymbolResourceHandle);
let rsc_table_get = self.intrinsic(Intrinsic::ResourceTableGet);
let rsc_flag = self.intrinsic(Intrinsic::ResourceTableFlag);
uwrite!(
self.src,
"var {rsc} = new.target === {local_name} ? this : Object.create({local_name}.prototype);
var {rep} = {rsc_table_get}(handleTable{id}, {handle}).rep;
Object.defineProperty({rsc}, {symbol_resource_handle}, {{ writable: true, value: {rep} }});
var {rep} = handleTable{id}[({handle} << 1) + 1] & ~{rsc_flag};
Object.defineProperty({rsc}, {symbol_resource_handle}, {{ writable: true, value: {rep} }});
",
);
if is_own {
Expand Down Expand Up @@ -1239,15 +1229,39 @@ impl Bindgen for FunctionBindgen<'_> {
));
}
} else {
// imported handles lift as instance capture from a previous lowering
let rsc_table_get = self.intrinsic(Intrinsic::ResourceTableGet);
uwriteln!(self.src, "var {rsc} = captureTable{id}.get({rsc_table_get}(handleTable{id}, {handle}).rep);");
// an own lifting is a transfer to JS, so handle is implicitly dropped
// imported handles either lift as instance capture from a previous lowering,
// or we create a new JS class to represent it
let rsc_flag = self.intrinsic(Intrinsic::ResourceTableFlag);
let symbol_resource_rep = self.intrinsic(Intrinsic::SymbolResourceRep);
let symbol_resource_handle =
self.intrinsic(Intrinsic::SymbolResourceHandle);
uwriteln!(
self.src,
"var {rep} = handleTable{id}[({handle} << 1) + 1] & ~{rsc_flag};"
);
uwriteln!(self.src,
"var {rsc} = captureTable{id}.get({rep});
if (!{rsc}) {{
{rsc} = Object.create({local_name}.prototype);
Object.defineProperty({rsc}, {symbol_resource_handle}, {{ writable: true, value: {handle} }});
Object.defineProperty({rsc}, {symbol_resource_rep}, {{ writable: true, value: {rep} }});
}}"
);
if is_own {
// an own lifting is a transfer to JS, so existing own handle is implicitly dropped
uwriteln!(
self.src,
"captureTable{id}.delete({rsc_table_remove}(handleTable{id}, {handle}).rep);"
"else {{
captureTable{id}.delete({rep});
}}
{rsc_table_remove}(handleTable{id}, {handle});"
);
} else {
// if lifting a borrow, that was not previously captured, create the class
self.cur_resource_borrows.push(format!(
"{}[{symbol_resource_handle}] = null;",
rsc.to_string()
));
}
}
}
Expand Down Expand Up @@ -1318,78 +1332,72 @@ impl Bindgen for FunctionBindgen<'_> {
ResourceData::Host { id, local_name, .. } => {
let id = id.as_u32();
if !imported {
let rep = format!("rep{}", self.tmp());

uwriteln!(
self.src,
"var {rep} = {op}[{symbol_resource_handle}];
if ({rep} === null) {{
throw new Error('Resource error: \"{class_name}\" lifetime expired.');
}}
if ({rep} === undefined) {{
"var {handle} = {op}[{symbol_resource_handle}];
if (!{handle}) {{
throw new Error('Resource error: Not a valid \"{class_name}\" resource.');
}}
",
);

// Own resources of own components lowered into the component
// still need handle table tracking of their rep value, by creating
// a new handle for this.
// The class representation of that own resource is still disposed
// though, and their finalizers deregistered as well.
if is_own {
let empty_func = self.intrinsic(Intrinsic::EmptyFunc);
let rsc_table_create_own =
self.intrinsic(Intrinsic::ResourceTableCreateOwn);
uwriteln!(
self.src,
"var {handle} = {rsc_table_create_own}(handleTable{id}, {rep});
finalizationRegistry{id}.unregister({op});
"finalizationRegistry{id}.unregister({op});
{op}[{symbol_dispose}] = {empty_func};
{op}[{symbol_resource_handle}] = null;"
);
} else {
// it is only in the local borrow case where we can simplify the handle
// to just be the original rep value and don't need to track an
// explicit handle lifetime.
uwriteln!(self.src, "var {handle} = {rep};");
}
} else {
// imported resources are always given a unique handle
// imported resources may already have a handle if they were constructed
// by a component and then passed out
uwriteln!(
self.src,
"if (!({op} instanceof {local_name})) {{
throw new Error('Resource error: Not a valid \"{class_name}\" resource.');
}}
captureTable{id}.set(++captureCnt{id}, {op});"
var {handle} = {op}[{symbol_resource_handle}];
"
);
// otherwise, in hybrid bindgen we check for a Symbol.for('cabiRep')
// to get the resource rep
// fall back to assign a new rep in the capture table, when the imported
// resource was constructed externally
if is_own {
let rsc_table_create_own =
let symbol_resource_rep =
self.intrinsic(Intrinsic::SymbolResourceRep);
let rsc_table_create =
self.intrinsic(Intrinsic::ResourceTableCreateOwn);
uwriteln!(
self.src,
"var {handle} = {rsc_table_create_own}(handleTable{id}, captureCnt{id});",
"if (!{handle}) {{
let rep = {op}[{symbol_resource_rep}];
if (!rep) {{
captureTable{id}.set(++captureCnt{id}, {op});
rep = captureCnt{id};
}} else {{
{op}[{symbol_resource_rep}] = null;
}}
{handle} = {rsc_table_create}(handleTable{id}, rep);
}}"
);
} else {
let rsc_table_create_borrow =
let symbol_resource_rep =
self.intrinsic(Intrinsic::SymbolResourceRep);
let rsc_table_create =
self.intrinsic(Intrinsic::ResourceTableCreateBorrow);
uwriteln!(
self.src,
"var {handle} = {rsc_table_create_borrow}(handleTable{id}, captureCnt{id});",
"if (!{handle}) {{
if (!{op}[{symbol_resource_rep}]) {{
captureTable{id}.set(++captureCnt{id}, {op});
}}
{handle} = {rsc_table_create}(handleTable{id}, {op}[{symbol_resource_rep}] || captureCnt{id});
}}"
);
}

// track lowered borrows to ensure they are dropped
// cur_resource_borrows can be reused because:
// - it is not possible to have a Wasm call that lifts a a borrow handle argument
// and wasm calls cannot return borrow handles for lifting
// - conversely, it is not possible to have a JS call that lowers a borrow handle argument
// and JS calls cannot return borrows for lowering
if !is_own && !self.valid_lifting_optimization {
let rsc_table_get = self.intrinsic(Intrinsic::ResourceTableGet);
self.cur_resource_borrows
.push(format!("{rsc_table_get}(handleTable{id}, {handle})"));
}
};
}
}

Expand Down
Loading

0 comments on commit 9058965

Please sign in to comment.