diff --git a/utils/jsffi/dyld.mjs b/utils/jsffi/dyld.mjs
index 2ec1958cfad4699d582d80d710b30116ca839b7f..aee3bf7f25b395dc924a20a50c04a733f96c6004 100755
--- a/utils/jsffi/dyld.mjs
+++ b/utils/jsffi/dyld.mjs
@@ -96,35 +96,80 @@ import { WASI } from "node:wasi";
import { JSValManager } from "./prelude.mjs";
import { parseRecord, parseSections } from "./post-link.mjs";
+// Make a consumer callback from a buffer. See Parser class
+// constructor comments for what a consumer is.
+function makeBufferConsumer(buf) {
+ return (len) => {
+ if (len > buf.length) {
+ throw new Error("not enough bytes");
+ }
+
+ const r = buf.subarray(0, len);
+ buf = buf.subarray(len);
+ return r;
+ };
+}
+
+// Make a consumer callback from a ReadableStreamDefaultReader.
+function makeStreamConsumer(reader) {
+ let buf = new Uint8Array();
+
+ return async (len) => {
+ while (buf.length < len) {
+ const { done, value } = await reader.read();
+ if (done) {
+ throw new Error("not enough bytes");
+ }
+ if (buf.length === 0) {
+ buf = value;
+ continue;
+ }
+ const tmp = new Uint8Array(buf.length + value.length);
+ tmp.set(buf, 0);
+ tmp.set(value, buf.length);
+ buf = tmp;
+ }
+
+ const r = buf.subarray(0, len);
+ buf = buf.subarray(len);
+ return r;
+ };
+}
+
// A simple binary parser
class Parser {
- #buf;
- #offset = 0;
-
- constructor(buf) {
- this.#buf = buf;
+ #cb;
+ #consumed = 0;
+ #limit;
+
+ // cb is a consumer callback that returns a buffer with exact N
+ // bytes for await cb(N). limit indicates how many bytes the Parser
+ // may consume at most; it's optional and only used by eof().
+ constructor(cb, limit) {
+ this.#cb = cb;
+ this.#limit = limit;
}
eof() {
- return this.#offset === this.#buf.length;
+ return this.#consumed >= this.#limit;
}
- skip(len) {
- this.#offset += len;
- console.assert(this.#offset <= this.#buf.length);
+ async skip(len) {
+ await this.#cb(len);
+ this.#consumed += len;
}
- readUInt8() {
- const r = this.#buf[this.#offset];
- this.#offset += 1;
+ async readUInt8() {
+ const r = (await this.#cb(1))[0];
+ this.#consumed += 1;
return r;
}
- readULEB128() {
+ async readULEB128() {
let acc = 0n,
shift = 0n;
while (true) {
- const byte = this.readUInt8();
+ const byte = await this.readUInt8();
acc |= BigInt(byte & 0x7f) << shift;
shift += 7n;
if (byte >> 7 === 0) {
@@ -134,41 +179,44 @@ class Parser {
return Number(acc);
}
- readBuffer() {
- const len = this.readULEB128();
- const r = this.#buf.subarray(this.#offset, this.#offset + len);
- this.#offset += len;
- console.assert(this.#offset <= this.#buf.length);
+ async readBuffer() {
+ const len = await this.readULEB128();
+ const r = await this.#cb(len);
+ this.#consumed += len;
return r;
}
- readString() {
- return new TextDecoder("utf-8", { fatal: true }).decode(this.readBuffer());
+ async readString() {
+ return new TextDecoder("utf-8", { fatal: true }).decode(
+ await this.readBuffer()
+ );
}
}
// Parse the dylink.0 section of a wasm module
-function parseDyLink0(buf) {
- const p0 = new Parser(buf);
+async function parseDyLink0(reader) {
+ const p0 = new Parser(makeStreamConsumer(reader));
// magic, version
- p0.skip(8);
+ await p0.skip(8);
// section id
- console.assert(p0.readUInt8() === 0);
- const p1 = new Parser(p0.readBuffer());
+ console.assert((await p0.readUInt8()) === 0);
+ const p1_buf = await p0.readBuffer();
+ const p1 = new Parser(makeBufferConsumer(p1_buf), p1_buf.length);
// custom section name
- console.assert(p1.readString() === "dylink.0");
+ console.assert((await p1.readString()) === "dylink.0");
const r = { neededSos: [], exportInfo: [], importInfo: [] };
while (!p1.eof()) {
- const subsection_type = p1.readUInt8();
- const p2 = new Parser(p1.readBuffer());
+ const subsection_type = await p1.readUInt8();
+ const p2_buf = await p1.readBuffer();
+ const p2 = new Parser(makeBufferConsumer(p2_buf), p2_buf.length);
switch (subsection_type) {
case 1: {
// WASM_DYLINK_MEM_INFO
- r.memSize = p2.readULEB128();
- r.memP2Align = p2.readULEB128();
- r.tableSize = p2.readULEB128();
- r.tableP2Align = p2.readULEB128();
+ r.memSize = await p2.readULEB128();
+ r.memP2Align = await p2.readULEB128();
+ r.tableSize = await p2.readULEB128();
+ r.tableP2Align = await p2.readULEB128();
break;
}
case 2: {
@@ -176,10 +224,10 @@ function parseDyLink0(buf) {
//
// There may be duplicate entries. Not a big deal to not
// dedupe, but why not.
- const n = p2.readULEB128();
+ const n = await p2.readULEB128();
const acc = new Set();
for (let i = 0; i < n; ++i) {
- acc.add(p2.readString());
+ acc.add(await p2.readString());
}
r.neededSos = [...acc];
break;
@@ -189,10 +237,10 @@ function parseDyLink0(buf) {
//
// Not actually used yet, kept for completeness in case of
// future usage.
- const n = p2.readULEB128();
+ const n = await p2.readULEB128();
for (let i = 0; i < n; ++i) {
- const name = p2.readString();
- const flags = p2.readULEB128();
+ const name = await p2.readString();
+ const flags = await p2.readULEB128();
r.exportInfo.push({ name, flags });
}
break;
@@ -201,11 +249,11 @@ function parseDyLink0(buf) {
// WASM_DYLINK_IMPORT_INFO
//
// Same.
- const n = p2.readULEB128();
+ const n = await p2.readULEB128();
for (let i = 0; i < n; ++i) {
- const module = p2.readString();
- const name = p2.readString();
- const flags = p2.readULEB128();
+ const module = await p2.readString();
+ const name = await p2.readString();
+ const flags = await p2.readULEB128();
r.importInfo.push({ module, name, flags });
}
break;
@@ -393,13 +441,15 @@ class DyLD {
p = await this.findSystemLibrary(p);
}
- const buf = await fs.promises.readFile(p);
- const modp = WebAssembly.compile(buf);
+ const resp = new Response(stream.Readable.toWeb(fs.createReadStream(p)), {
+ headers: { "Content-Type": "application/wasm" },
+ });
+ const resp2 = resp.clone();
+ const modp = WebAssembly.compileStreaming(resp);
// Parse dylink.0 from the raw buffer, not via
- // WebAssembly.Module.customSections(). At this point we only care
- // about WASM_DYLINK_NEEDED, but might as well do the rest of the
- // parsing anyway.
- const r = parseDyLink0(buf);
+ // WebAssembly.Module.customSections(). This should return asap
+ // without waiting for rest of the wasm module binary data.
+ const r = await parseDyLink0(resp2.body.getReader());
r.modp = modp;
r.soname = soname;
let acc = [];