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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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/*
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Saving blobs to hub
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*/
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import { getLogger } from "@cocalc/backend/logger";
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import * as message from "@cocalc/util/message";
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import { defaults, required, uuid } from "@cocalc/util/misc";
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import { CB } from "@cocalc/util/types/database";
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const winston = getLogger("blobs");
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type BlobCB = CB<any, { sha1: string; error: string }>;
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type CBEntry = [BlobCB, string];
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const _save_blob_callbacks: { [key: string]: CBEntry[] } = {};
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interface Opts {
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  sha1: string;
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  cb: BlobCB;
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  timeout?: number;
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}
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export function receive_save_blob_message(opts: Opts): void {
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  // temporarily used by file_session_manager
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  opts = defaults(opts, {
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    sha1: required,
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    cb: required,
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    timeout: 30, // seconds; maximum time in seconds to wait for response message
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  });
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  winston.debug(`receive_save_blob_message: ${opts.sha1}`);
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  const { sha1 } = opts;
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  const id = uuid();
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  _save_blob_callbacks[sha1] ??= [];
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  _save_blob_callbacks[sha1].push([opts.cb, id]);
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  // Timeout functionality -- send a response after opts.timeout seconds,
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  // in case no hub responded.
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  if (!opts.timeout) {
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    return;
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  }
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  const f = function (): void {
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    const v = _save_blob_callbacks[sha1];
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    if (v != null) {
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      const mesg = message.save_blob({
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        sha1,
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        error: `timed out after local hub waited for ${opts.timeout} seconds`,
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      });
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      const w: CBEntry[] = [];
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      for (let x of v) {
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        // this is O(n) instead of O(1), but who cares since n is usually 1.
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        if (x[1] === id) {
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          x[0](mesg);
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        } else {
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          w.push(x);
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        }
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      }
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      if (w.length === 0) {
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        delete _save_blob_callbacks[sha1];
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      } else {
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        _save_blob_callbacks[sha1] = w;
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      }
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    }
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  };
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  setTimeout(f, opts.timeout * 1000);
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}
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export function handle_save_blob_message(mesg): void {
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  winston.debug(`handle_save_blob_message: ${mesg.sha1}`);
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  const v = _save_blob_callbacks[mesg.sha1];
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  if (v != null) {
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    for (let x of v) {
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      x[0](mesg);
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    }
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    delete _save_blob_callbacks[mesg.sha1];
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  }
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}
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