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/*
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 *  This file is part of CoCalc: Copyright © 2023 Sagemath, Inc.
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 *  License: MS-RSL – see LICENSE.md for details
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 */
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import { readFile } from "node:fs/promises";
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import { sageServerPaths } from "@cocalc/project/data";
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type Type = "sage";
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/*
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The port_manager manages the ports for the sage worksheet server.
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*/
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// a local cache
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const ports: { [type in Type]?: number } = {};
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export async function get_port(type: Type = "sage"): Promise<number> {
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  const val = ports[type];
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  if (val != null) {
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    return val;
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  } else {
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    const content = await readFile(sageServerPaths.port);
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    try {
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      const val = parseInt(content.toString());
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      ports[type] = val;
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      return val;
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    } catch (err) {
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      throw new Error(`${type}_server port file corrupted -- ${err}`);
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    }
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  }
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}
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export function forget_port(type: Type = "sage") {
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  if (ports[type] != null) {
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    delete ports[type];
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  }
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}
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