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/** For internal Diplomat use when constructing opaques or out structs.
* This is for when we're handling items that we don't want the user to touch, like an structure that's only meant to be output, or de-referencing a pointer we're handed from WASM.
*/
export const internalConstructor = Symbol("constructor");
/** For internal Diplomat use when accessing a from-fields/from-value constructor that's been overridden by a default constructor.
* If we want to pass in arguments without also passing in internalConstructor to avoid triggering some logic we don't want, we use exposeConstructor.
*/
export const exposeConstructor = Symbol("exposeConstructor");
export function readString8(wasm, ptr, len) {
const buf = new Uint8Array(wasm.memory.buffer, ptr, len);
return (new TextDecoder("utf-8")).decode(buf)
}
export function readString16(wasm, ptr, len) {
const buf = new Uint16Array(wasm.memory.buffer, ptr, len);
return String.fromCharCode.apply(null, buf)
}
export function withDiplomatWrite(wasm, callback) {
const write = wasm.diplomat_buffer_write_create(0);
try {
callback(write);
const outStringPtr = wasm.diplomat_buffer_write_get_bytes(write);
if (outStringPtr === null) {
throw Error("Out of memory");
}
const outStringLen = wasm.diplomat_buffer_write_len(write);
return readString8(wasm, outStringPtr, outStringLen);
} finally {
wasm.diplomat_buffer_write_destroy(write);
}
}
/**
* Get the pointer returned by an FFI function.
*
* It's tempting to call `(new Uint32Array(wasm.memory.buffer, FFI_func(), 1))[0]`.
* However, there's a chance that `wasm.memory.buffer` will be resized between
* the time it's accessed and the time it's used, invalidating the view.
* This function ensures that the view into wasm memory is fresh.
*
* This is used for methods that return multiple types into a wasm buffer, where
* one of those types is another ptr. Call this method to get access to the returned
* ptr, so the return buffer can be freed.
* @param {WebAssembly.Exports} wasm Provided by diplomat generated files.
* @param {number} ptr Pointer of a pointer, to be read.
* @returns {number} The underlying pointer.
*/
export function ptrRead(wasm, ptr) {
return (new Uint32Array(wasm.memory.buffer, ptr, 1))[0];
}
/**
* Get the flag of a result type.
*/
export function resultFlag(wasm, ptr, offset) {
return (new Uint8Array(wasm.memory.buffer, ptr + offset, 1))[0];
}
/**
* Get the discriminant of a Rust enum.
*/
export function enumDiscriminant(wasm, ptr) {
return (new Int32Array(wasm.memory.buffer, ptr, 1))[0]
}
/**
* Return an array of paddingCount zeroes to be spread into a function call
* if needsPaddingFields is true, else empty
*/
export function maybePaddingFields(needsPaddingFields, paddingCount) {
if (needsPaddingFields) {
return Array(paddingCount).fill(0);
} else {
return [];
}
}
/**
* Write a value of width `width` to a an ArrayBuffer `arrayBuffer`
* at byte offset `offset`, treating it as a buffer of kind `typedArrayKind`
* (which is a `TypedArray` variant like `Uint8Array` or `Int16Array`)
*/
export function writeToArrayBuffer(arrayBuffer, offset, value, typedArrayKind) {
let buffer = new typedArrayKind(arrayBuffer, offset);
buffer[0] = value;
}
/**
* Take `jsValue` and write it to arrayBuffer at offset `offset` if it is non-null
* calling `writeToArrayBufferCallback(arrayBuffer, offset, jsValue)` to write to the buffer,
* also writing a tag bit.
*
* `size` and `align` are the size and alignment of T, not of Option<T>
*/
export function writeOptionToArrayBuffer(arrayBuffer, offset, jsValue, size, align, writeToArrayBufferCallback) {
// perform a nullish check, not a null check,
// we want identical behavior for undefined
if (jsValue != null) {
writeToArrayBufferCallback(arrayBuffer, offset, jsValue);
writeToArrayBuffer(arrayBuffer, offset + size, 1, Uint8Array);
}
}
/**
* For Option<T> of given size/align (of T, not the overall option type),
* return an array of fields suitable for passing down to a parameter list.
*
* Calls writeToArrayBufferCallback(arrayBuffer, offset, jsValue) for non-null jsValues
*
* This array will have size<T>/align<T> elements for the actual T, then one element
* for the is_ok bool, and then align<T> - 1 elements for padding.
*
* See wasm_abi_quirks.md's section on Unions for understanding this ABI.
*/
export function optionToArgsForCalling(jsValue, size, align, writeToArrayBufferCallback) {
let args;
// perform a nullish check, not a null check,
// we want identical behavior for undefined
if (jsValue != null) {
let buffer;
// We need our originator array to be properly aligned
if (align == 8) {
buffer = new BigUint64Array(size / align);
} else if (align == 4) {
buffer = new Uint32Array(size / align);
} else if (align == 2) {
buffer = new Uint16Array(size / align);
} else {
buffer = new Uint8Array(size / align);
}
writeToArrayBufferCallback(buffer.buffer, 0, jsValue);
args = Array.from(buffer);
args.push(1);
} else {
args = Array(size / align).fill(0);
args.push(0);
}
// Unconditionally add padding
args = args.concat(Array(align - 1).fill(0));
return args;
}
export function optionToBufferForCalling(wasm, jsValue, size, align, allocator, writeToArrayBufferCallback) {
let buf = DiplomatBuf.struct(wasm, size, align);
let buffer;
// Add 1 to the size since we're also accounting for the 0 or 1 is_ok field:
if (align == 8) {
buffer = new BigUint64Array(wasm.memory.buffer, buf, size / align + 1);
} else if (align == 4) {
buffer = new Uint32Array(wasm.memory.buffer, buf, size / align + 1);
} else if (align == 2) {
buffer = new Uint16Array(wasm.memory.buffer, buf, size / align + 1);
} else {
buffer = new Uint8Array(wasm.memory.buffer, buf, size / align + 1);
}
buffer.fill(0);
if (jsValue != null) {
writeToArrayBufferCallback(buffer.buffer, 0, jsValue);
buffer[buffer.length - 1] = 1;
}
allocator.alloc(buf);
}
/**
* Given `ptr` in Wasm memory, treat it as an Option<T> with size for type T,
* and return the converted T (converted using `readCallback(wasm, ptr)`) if the Option is Some
* else None.
*/
export function readOption(wasm, ptr, size, readCallback) {
// Don't need the alignment: diplomat types don't have overridden alignment,
// so the flag will immediately be after the inner struct.
let flag = resultFlag(wasm, ptr, size);
if (flag) {
return readCallback(wasm, ptr);
} else {
return null;
}
}
/**
* A wrapper around a slice of WASM memory that can be freed manually or
* automatically by the garbage collector.
*
* This type is necessary for Rust functions that take a `&str` or `&[T]`, since
* they can create an edge to this object if they borrow from the str/slice,
* or we can manually free the WASM memory if they don't.
*/
export class DiplomatBuf {
static str8 = (wasm, string) => {
var utf8Length = 0;
for (const codepointString of string) {
let codepoint = codepointString.codePointAt(0);
if (codepoint < 0x80) {
utf8Length += 1
} else if (codepoint < 0x800) {
utf8Length += 2
} else if (codepoint < 0x10000) {
utf8Length += 3
} else {
utf8Length += 4
}
}
const ptr = wasm.diplomat_alloc(utf8Length, 1);
const result = (new TextEncoder()).encodeInto(string, new Uint8Array(wasm.memory.buffer, ptr, utf8Length));
console.assert(string.length === result.read && utf8Length === result.written, "UTF-8 write error");
return new DiplomatBuf(ptr, utf8Length, () => wasm.diplomat_free(ptr, utf8Length, 1));
}
static str16 = (wasm, string) => {
const byteLength = string.length * 2;
const ptr = wasm.diplomat_alloc(byteLength, 2);
const destination = new Uint16Array(wasm.memory.buffer, ptr, string.length);
for (let i = 0; i < string.length; i++) {
destination[i] = string.charCodeAt(i);
}
return new DiplomatBuf(ptr, string.length, () => wasm.diplomat_free(ptr, byteLength, 2));
}
static sliceWrapper = (wasm, buf) => {
const ptr = wasm.diplomat_alloc(8, 4);
let dst = new Uint32Array(wasm.memory.buffer, ptr, 2);
dst[0] = buf.ptr;
dst[1] = buf.size;
return new DiplomatBuf(ptr, 8, () => {
wasm.diplomat_free(ptr, 8, 4);
buf.free();
});
}
static slice = (wasm, list, rustType) => {
const elementSize = rustType === "u8" || rustType === "i8" || rustType === "boolean" ? 1 :
rustType === "u16" || rustType === "i16" ? 2 :
rustType === "u64" || rustType === "i64" || rustType === "f64" ? 8 :
4;
const byteLength = list.length * elementSize;
const ptr = wasm.diplomat_alloc(byteLength, elementSize);
/**
* Create an array view of the buffer. This gives us the `set` method which correctly handles untyped values
*/
const destination =
rustType === "u8" || rustType === "boolean" ? new Uint8Array(wasm.memory.buffer, ptr, byteLength) :
rustType === "i8" ? new Int8Array(wasm.memory.buffer, ptr, byteLength) :
rustType === "u16" ? new Uint16Array(wasm.memory.buffer, ptr, byteLength) :
rustType === "i16" ? new Int16Array(wasm.memory.buffer, ptr, byteLength) :
rustType === "i32" ? new Int32Array(wasm.memory.buffer, ptr, byteLength) :
rustType === "u64" ? new BigUint64Array(wasm.memory.buffer, ptr, byteLength) :
rustType === "i64" ? new BigInt64Array(wasm.memory.buffer, ptr, byteLength) :
rustType === "f32" ? new Float32Array(wasm.memory.buffer, ptr, byteLength) :
rustType === "f64" ? new Float64Array(wasm.memory.buffer, ptr, byteLength) :
new Uint32Array(wasm.memory.buffer, ptr, byteLength);
destination.set(list);
return new DiplomatBuf(ptr, list.length, () => wasm.diplomat_free(ptr, byteLength, elementSize));
}
static strs = (wasm, strings, encoding) => {
let encodeStr = (encoding === "string16") ? DiplomatBuf.str16 : DiplomatBuf.str8;
const byteLength = strings.length * 4 * 2;
const ptr = wasm.diplomat_alloc(byteLength, 4);
const destination = new Uint32Array(wasm.memory.buffer, ptr, byteLength);
const stringsAlloc = [];
for (let i = 0; i < strings.length; i++) {
stringsAlloc.push(encodeStr(wasm, strings[i]));
destination[2 * i] = stringsAlloc[i].ptr;
destination[(2 * i) + 1] = stringsAlloc[i].size;
}
return new DiplomatBuf(ptr, strings.length, () => {
wasm.diplomat_free(ptr, byteLength, 4);
for (let i = 0; i < stringsAlloc.length; i++) {
stringsAlloc[i].free();
}
});
}
static struct = (wasm, size, align) => {
const ptr = wasm.diplomat_alloc(size, align);
return new DiplomatBuf(ptr, size, () => {
wasm.diplomat_free(ptr, size, align);
});
}
/**
* Generated code calls one of methods these for each allocation, to either
* free directly after the FFI call, to leak (to create a &'static), or to
* register the buffer with the garbage collector (to create a &'a).
*/
free;
constructor(ptr, size, free) {
this.ptr = ptr;
this.size = size;
this.free = free;
this.leak = () => { };
this.releaseToGarbageCollector = () => DiplomatBufferFinalizer.register(this, this.free);
}
splat() {
return [this.ptr, this.size];
}
/**
* Write the (ptr, len) pair to an array buffer at byte offset `offset`
*/
writePtrLenToArrayBuffer(arrayBuffer, offset) {
writeToArrayBuffer(arrayBuffer, offset, this.ptr, Uint32Array);
writeToArrayBuffer(arrayBuffer, offset + 4, this.size, Uint32Array);
}
}
/**
* Helper class for creating and managing `diplomat_buffer_write`.
* Meant to minimize direct calls to `wasm`.
*/
export class DiplomatWriteBuf {
leak;
#wasm;
#buffer;
constructor(wasm) {
this.#wasm = wasm;
this.#buffer = this.#wasm.diplomat_buffer_write_create(0);
this.leak = () => { };
}
free() {
this.#wasm.diplomat_buffer_write_destroy(this.#buffer);
}
releaseToGarbageCollector() {
DiplomatBufferFinalizer.register(this, this.free);
}
readString8() {
return readString8(this.#wasm, this.ptr, this.size);
}
get buffer() {
return this.#buffer;
}
get ptr() {
return this.#wasm.diplomat_buffer_write_get_bytes(this.#buffer);
}
get size() {
return this.#wasm.diplomat_buffer_write_len(this.#buffer);
}
}
/**
* Represents an underlying slice that we've grabbed from WebAssembly.
* You can treat this in JS as a regular slice of primitives, but it handles additional data for you behind the scenes.
*/
export class DiplomatSlice {
#wasm;
#bufferType;
get bufferType() {
return this.#bufferType;
}
#buffer;
get buffer() {
return this.#buffer;
}
#lifetimeEdges;
constructor(wasm, buffer, bufferType, lifetimeEdges) {
this.#wasm = wasm;
const [ptr, size] = new Uint32Array(this.#wasm.memory.buffer, buffer, 2);
this.#buffer = new bufferType(this.#wasm.memory.buffer, ptr, size);
this.#bufferType = bufferType;
this.#lifetimeEdges = lifetimeEdges;
}
getValue() {
return this.#buffer;
}
[Symbol.toPrimitive]() {
return this.getValue();
}
valueOf() {
return this.getValue();
}
}
export class DiplomatSlicePrimitive extends DiplomatSlice {
constructor(wasm, buffer, sliceType, lifetimeEdges) {
const [ptr, size] = new Uint32Array(wasm.memory.buffer, buffer, 2);
let arrayType;
switch (sliceType) {
case "u8":
case "boolean":
arrayType = Uint8Array;
break;
case "i8":
arrayType = Int8Array;
break;
case "u16":
arrayType = Uint16Array;
break;
case "i16":
arrayType = Int16Array;
break;
case "i32":
arrayType = Int32Array;
break;
case "u32":
arrayType = Uint32Array;
break;
case "i64":
arrayType = BigInt64Array;
break;
case "u64":
arrayType = BigUint64Array;
break;
case "f32":
arrayType = Float32Array;
break;
case "f64":
arrayType = Float64Array;
break;
default:
console.error("Unrecognized bufferType ", bufferType);
}
super(wasm, buffer, arrayType, lifetimeEdges);
}
}
export class DiplomatSliceStr extends DiplomatSlice {
#decoder;
constructor(wasm, buffer, stringEncoding, lifetimeEdges) {
let encoding;
switch (stringEncoding) {
case "string8":
encoding = Uint8Array;
break;
case "string16":
encoding = Uint16Array;
break;
default:
console.error("Unrecognized stringEncoding ", stringEncoding);
break;
}
super(wasm, buffer, encoding, lifetimeEdges);
if (stringEncoding === "string8") {
this.#decoder = new TextDecoder('utf-8');
}
}
getValue() {
switch (this.bufferType) {
case Uint8Array:
return this.#decoder.decode(super.getValue());
case Uint16Array:
return String.fromCharCode.apply(null, super.getValue());
default:
return null;
}
}
toString() {
return this.getValue();
}
}
export class DiplomatSliceStrings extends DiplomatSlice {
#strings = [];
constructor(wasm, buffer, stringEncoding, lifetimeEdges) {
super(wasm, buffer, Uint32Array, lifetimeEdges);
for (let i = this.buffer.byteOffset; i < this.buffer.byteLength; i += this.buffer.BYTES_PER_ELEMENT * 2) {
this.#strings.push(new DiplomatSliceStr(wasm, i, stringEncoding, lifetimeEdges));
}
}
getValue() {
return this.#strings;
}
}
/**
* A number of Rust functions in WebAssembly require a buffer to populate struct, slice, Option<> or Result<> types with information.
* {@link DiplomatReceiveBuf} allocates a buffer in WebAssembly, which can then be passed into functions with the {@link DiplomatReceiveBuf.buffer}
* property.
*/
export class DiplomatReceiveBuf {
#wasm;
#size;
#align;
#hasResult;
#buffer;
constructor(wasm, size, align, hasResult) {
this.#wasm = wasm;
this.#size = size;
this.#align = align;
this.#hasResult = hasResult;
this.#buffer = this.#wasm.diplomat_alloc(this.#size, this.#align);
this.leak = () => { };
}
free() {
this.#wasm.diplomat_free(this.#buffer, this.#size, this.#align);
}
get buffer() {
return this.#buffer;
}
/**
* Only for when a DiplomatReceiveBuf is allocating a buffer for an `Option<>` or a `Result<>` type.
*
* This just checks the last byte for a successful result (assuming that Rust's compiler does not change).
*/
get resultFlag() {
if (this.#hasResult) {
return resultFlag(this.#wasm, this.#buffer, this.#size - 1);
} else {
return true;
}
}
}
/**
* For cleaning up slices inside struct _intoFFI functions.
* Based somewhat on how the Dart backend handles slice cleanup.
*
* We want to ensure a slice only lasts as long as its struct, so we have a `functionCleanupArena` CleanupArena that we use in each method for any slice that needs to be cleaned up. It lasts only as long as the function is called for.
*
* Then we have `createWith`, which is meant for longer lasting slices. It takes an array of edges and will last as long as those edges do. Cleanup is only called later.
*/
export class CleanupArena {
#items = [];
constructor() {
}
/**
* When this arena is freed, call .free() on the given item.
* @param {DiplomatBuf} item
* @returns {DiplomatBuf}
*/
alloc(item) {
this.#items.push(item);
return item;
}
/**
* Create a new CleanupArena, append it to any edge arrays passed down, and return it.
* @param {Array} edgeArrays
* @returns {CleanupArena}
*/
static createWith(...edgeArrays) {
let self = new CleanupArena();
for (let edgeArray of edgeArrays) {
if (edgeArray != null) {
edgeArray.push(self);
}
}
DiplomatBufferFinalizer.register(self, self.free);
return self;
}
/**
* If given edge arrays, create a new CleanupArena, append it to any edge arrays passed down, and return it.
* Else return the function-local cleanup arena
* @param {CleanupArena} functionCleanupArena
* @param {Array} edgeArrays
* @returns {DiplomatBuf}
*/
static maybeCreateWith(functionCleanupArena, ...edgeArrays) {
if (edgeArrays.length > 0) {
return CleanupArena.createWith(...edgeArrays);
} else {
return functionCleanupArena
}
}
free() {
this.#items.forEach((i) => {
i.free();
});
this.#items.length = 0;
}
}
/**
* Similar to {@link CleanupArena}, but for holding on to slices until a method is called,
* after which we rely on the GC to free them.
*
* This is when you may want to use a slice longer than the body of the method.
*
* At first glance this seems unnecessary, since we will be holding these slices in edge arrays anyway,
* however, if an edge array ends up unused, then we do actually need something to hold it for the duration
* of the method call.
*/
export class GarbageCollectorGrip {
#items = [];
alloc(item) {
this.#items.push(item);
return item;
}
releaseToGarbageCollector() {
this.#items.forEach((i) => {
i.releaseToGarbageCollector();
});
this.#items.length = 0;
}
}
const DiplomatBufferFinalizer = new FinalizationRegistry(free => free());