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fix scrammaps
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@r58Playz
r58Playz committed Mar 7, 2025
1 parent e8ff38b commit f15cf56
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Showing 4 changed files with 105 additions and 80 deletions.
4 changes: 2 additions & 2 deletions src/client/shared/function.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -5,11 +5,11 @@ function rewriteFunction(ctx: ProxyCtx, client: ScramjetClient) {
const stringifiedFunction = ctx.call().toString();

const content = rewriteJs(
`return ${stringifiedFunction}`,
stringifiedFunction,
"(function proxy)",
client.meta
);
ctx.return(ctx.fn(content)());
ctx.return(ctx.fn(`return ${content}`)());
}

export default function (client: ScramjetClient, _self: Self) {
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169 changes: 92 additions & 77 deletions src/client/shared/sourcemaps.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -6,27 +6,28 @@ enum RewriteType {
Replace = 1,
}

type Rewrite =
type Rewrite = {
start: number;
} & (
| {
type: RewriteType.Insert;
// offset before this rewrite
offset: number;
// start of insertion
start: number;
// size of insertion
size: number;
}
| {
type: RewriteType.Replace;
// offset before this rewrite
offset: number;
// start of replacement
start: number;
// end of replacement
end: number;
// old string
str: string;
};
}
);

function getEnd(rewrite: Rewrite): number {
if (rewrite.type === RewriteType.Insert) {
return rewrite.start + rewrite.size;
} else if (rewrite.type === RewriteType.Replace) {
return rewrite.end;
}
throw "unreachable";
}

const sourcemaps: Record<string, Rewrite[]> = {};

Expand All @@ -35,49 +36,53 @@ export const enabled = (client: ScramjetClient) =>

export default function (client: ScramjetClient, self: Self) {
// every script will push a sourcemap
Object.defineProperty(self, $scramjet.config.globals.pushsourcemapfn, {
value: (buf: Array<number>, tag: string) => {
const sourcemap = Uint8Array.from(buf);
const view = new DataView(sourcemap.buffer);
const decoder = new TextDecoder("utf-8");

const rewrites = [];

const rewritelen = view.getUint32(0, true);
let cursor = 0;
for (let i = 0; i < rewritelen; i++) {
const type = view.getUint8(cursor) as RewriteType;
cursor += 1;

if (type == RewriteType.Insert) {
const offset = view.getUint32(cursor, true);
cursor += 4;
const start = view.getUint32(cursor, true);
cursor += 4;
const size = view.getUint32(cursor, true);
cursor += 4;

rewrites.push({ type, offset, start, size });
} else if (type == RewriteType.Replace) {
const offset = view.getUint32(cursor, true);
cursor += 4;
const start = view.getUint32(cursor, true);
cursor += 4;
const end = view.getUint32(cursor, true);
cursor += 4;

const str = decoder.decode(sourcemap.subarray(start, end));

rewrites.push({ type, offset, start, end, str });
Object.defineProperty(
self,
globalThis.$scramjet.config.globals.pushsourcemapfn,
{
value: (buf: Array<number>, tag: string) => {
const sourcemap = Uint8Array.from(buf);
const view = new DataView(sourcemap.buffer);
const decoder = new TextDecoder("utf-8");

const rewrites: Rewrite[] = [];

const rewritelen = view.getUint32(0, true);
let cursor = 4;
for (let i = 0; i < rewritelen; i++) {
const type = view.getUint8(cursor) as RewriteType;
cursor += 1;

if (type == RewriteType.Insert) {
const start = view.getUint32(cursor, true);
cursor += 4;
const size = view.getUint32(cursor, true);
cursor += 4;

rewrites.push({ type, start, size });
} else if (type == RewriteType.Replace) {
const start = view.getUint32(cursor, true);
cursor += 4;
const end = view.getUint32(cursor, true);
cursor += 4;
const len = view.getUint32(cursor, true);
cursor += 4;

const str = decoder.decode(
sourcemap.subarray(cursor, cursor + len)
);

rewrites.push({ type, start, end, str });
}
}
}

sourcemaps[tag] = rewrites;
},
enumerable: false,
writable: false,
configurable: false,
});
sourcemaps[tag] = rewrites;
},
enumerable: false,
writable: false,
configurable: false,
}
);

const scramtag_ident = "/*scramtag ";

Expand All @@ -86,7 +91,6 @@ export default function (client: ScramjetClient, self: Self) {
client.Proxy("Function.prototype.toString", {
apply(ctx) {
let stringified: string = ctx.fn.call(ctx.this);
let newString = "";

// every function rewritten will have a scramtag comment
// it will look like this:
Expand All @@ -106,39 +110,50 @@ export default function (client: ScramjetClient, self: Self) {

// subtracting that from the index of the scramtag gives us the starting index of the function relative to the entire file
const absindex = abstagindex - scramtagstart;
const endindex = absindex + stringified.length;

const scramtagend = stringified.indexOf("*/", scramtagstart);
const tag = stringified.substring(firstspace + 1, scramtagend);

// delete all scramtags inside the function (and nested ones!!)
stringified = stringified.replace(/\/\*scramtag.*?\*\//g, "");
const rewrites = sourcemaps[tag];

const maps = sourcemaps[tag];
if (!rewrites) {
console.warn("failed to get rewrites for tag", tag);
return ctx.return(stringified);
}

let i = 0;
let offset = 0;

let j = 0;
while (j < maps.length) {
/* TODO
const [str, start, end] = maps[j];
if (start < absindex) {
j++;
continue;
}
if (start - absindex + offset > stringified.length) break;
// skip all rewrites in the file before the fn
while (i < rewrites.length) {
if (rewrites[i].start < absindex) i++;
else break;
}

let end = i;
while (end < rewrites.length) {
if (getEnd(rewrites[end]) < endindex) end++;
else break;
}

// ooh i should really document this before i forget how it works
newString += stringified.slice(i, start - absindex + offset);
newString += str;
offset += end - start - str.length;
i = start - absindex + offset + str.length;
const fnrewrites = rewrites.slice(i, end);

j++;
*/
let newString = "";
let lastpos = absindex;

for (const rewrite of fnrewrites) {
newString += stringified.slice(lastpos, rewrite.start);

if (rewrite.type === RewriteType.Insert) {
lastpos = rewrite.start + rewrite.size;
} else if (rewrite.type === RewriteType.Replace) {
newString += rewrite.str;
lastpos = rewrite.end;
} else {
throw "unreachable";
}
}

newString += stringified.slice(i);
newString += stringified.slice(lastpos);

return ctx.return(newString);
},
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9 changes: 8 additions & 1 deletion src/shared/rewriters/js.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -62,7 +62,14 @@ function rewriteJsWrapper(
return input;
}
const after = performance.now();
const { js, errors, duration } = out;
const { js, map, scramtag, errors, duration } = out;

if ((flagEnabled("sourcemaps", meta.base), !globalThis.clients)) {
globalThis[globalThis.$scramjet.config.globals.pushsourcemapfn](
Array.from(map),
scramtag
);
}

if (flagEnabled("rewriterLogs", meta.base)) {
for (const error of errors) {
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3 changes: 3 additions & 0 deletions static/ui.js
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Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,9 @@ const scramjet = new ScramjetController({
shared: "/scram/scramjet.shared.js",
sync: "/scram/scramjet.sync.js",
},
flags: {
sourcemaps: true,
},
siteFlags: {
"https://worker-playground.glitch.me/.*": {
serviceworkers: true,
Expand Down

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