decentralised sync engine
feat: initial implementation
+98
-4
+48
-4
src/index.ts
+48
-4
src/index.ts
···
1
-
const main = () => {
2
-
console.log("Hello!!");
3
-
};
1
+
import { rawDataToString } from "@/lib/utils";
2
+
import { validateShardMessage, type ShardMessage } from "@/lib/validator";
3
+
import type { RawData } from "ws";
4
+
import WebSocket from "ws";
5
+
6
+
const wss = new WebSocket.Server({ port: 8080 });
7
+
8
+
const messages: ShardMessage[] = []; // Store message history
9
+
const clients = new Set<WebSocket>();
4
10
5
-
main();
11
+
wss.on("connection", (ws) => {
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+
clients.add(ws);
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+
14
+
// Send history to new client
15
+
ws.send(
16
+
JSON.stringify({
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+
type: "shard/history",
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+
messages: messages,
19
+
}),
20
+
);
21
+
22
+
ws.on("message", (data: RawData) => {
23
+
const jsonText = rawDataToString(data);
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+
const jsonData: unknown = JSON.parse(jsonText);
25
+
const {
26
+
success,
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+
error,
28
+
data: shardMessage,
29
+
} = validateShardMessage(jsonData);
30
+
31
+
if (!success) {
32
+
console.log(error);
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+
} else {
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+
messages.push(shardMessage);
35
+
}
36
+
37
+
clients.forEach((client) => {
38
+
if (client.readyState === WebSocket.OPEN) {
39
+
client.send(JSON.stringify(shardMessage));
40
+
}
41
+
});
42
+
});
43
+
44
+
ws.on("close", () => {
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+
clients.delete(ws);
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+
});
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+
});
48
+
49
+
console.log("Server running on ws://localhost:8080");
+11
src/lib/utils.ts
+11
src/lib/utils.ts
···
1
+
import type { RawData } from "ws";
2
+
3
+
export const rawDataToString = (data: RawData): string => {
4
+
if (Buffer.isBuffer(data)) {
5
+
return data.toString("utf-8");
6
+
}
7
+
if (Array.isArray(data)) {
8
+
return Buffer.concat(data).toString("utf-8");
9
+
}
10
+
return new TextDecoder().decode(data);
11
+
};
+39
src/lib/validator.ts
+39
src/lib/validator.ts
···
1
+
export function assertShardMessage(
2
+
json: unknown,
3
+
): asserts json is ShardMessage {
4
+
if (typeof json !== "object") {
5
+
throw new Error("not a js object");
6
+
}
7
+
8
+
const candidate = json as Record<string, unknown>;
9
+
10
+
if (candidate.type !== "shard/message") {
11
+
throw new Error("Invalid type");
12
+
}
13
+
14
+
if (typeof candidate.text !== "string") {
15
+
throw new Error("Invalid text");
16
+
}
17
+
18
+
const timestamp = new Date(candidate.timestamp as string);
19
+
20
+
if (!(timestamp instanceof Date)) {
21
+
throw new Error("Invalid timestamp");
22
+
}
23
+
}
24
+
25
+
// example. we will use zod in the future.
26
+
export const validateShardMessage = (json: unknown) => {
27
+
try {
28
+
assertShardMessage(json);
29
+
return { success: true, data: json };
30
+
} catch (e: unknown) {
31
+
return { error: e };
32
+
}
33
+
};
34
+
35
+
export interface ShardMessage {
36
+
type: "shard/message";
37
+
text: string;
38
+
timestamp: Date;
39
+
}