envio/src/LazyLoader.res.js

A latency and sync speed optimized, developer friendly blockchain data indexer.

// Generated by ReScript, PLEASE EDIT WITH CARE
'use strict';

var Utils = require("./Utils.res.js");
var JsSdsl = require("js-sdsl");
var Belt_Option = require("rescript/lib/js/belt_Option.js");
var Caml_option = require("rescript/lib/js/caml_option.js");
var Caml_exceptions = require("rescript/lib/js/caml_exceptions.js");
var Caml_js_exceptions = require("rescript/lib/js/caml_js_exceptions.js");

var LoaderTimeout = /* @__PURE__ */Caml_exceptions.create("LazyLoader.LoaderTimeout");

function make(loaderFn, onError, cacheSizeOpt, loaderPoolSizeOpt, retryDelayMillisOpt, timeoutMillisOpt) {
  var cacheSize = cacheSizeOpt !== undefined ? cacheSizeOpt : 10000;
  var loaderPoolSize = loaderPoolSizeOpt !== undefined ? loaderPoolSizeOpt : 10;
  var retryDelayMillis = retryDelayMillisOpt !== undefined ? retryDelayMillisOpt : 5000;
  var timeoutMillis = timeoutMillisOpt !== undefined ? timeoutMillisOpt : 300000;
  return {
          _cacheSize: cacheSize,
          _loaderPoolSize: loaderPoolSize,
          _retryDelayMillis: retryDelayMillis,
          _timeoutMillis: timeoutMillis,
          externalPromises: new Map(),
          resolvers: new Map(),
          inProgress: new Set(),
          loaderQueue: new JsSdsl.Queue(),
          loadedKeys: new JsSdsl.Queue(),
          loaderFn: loaderFn,
          onError: onError
        };
}

function deleteKey(_obj, _k) {
  ((delete _obj[_k]));
}

function timeoutAfter(timeoutMillis) {
  return Utils.delay(timeoutMillis).then(function () {
              return Promise.reject({
                          RE_EXN_ID: LoaderTimeout,
                          _1: "Query took longer than " + String(timeoutMillis / 1000 | 0) + " seconds"
                        });
            });
}

async function loadNext(am, k) {
  am.inProgress.add(k);
  var awaitTaskPromiseAndLoadNextWithTimeout = async function () {
    var val = await Promise.race([
          am.loaderFn(k),
          timeoutAfter(am._timeoutMillis)
        ]);
    Belt_Option.forEach(am.resolvers.get(k), (function (r) {
            am.resolvers.delete(k);
            r(val);
          }));
    am.inProgress.delete(k);
    var loadedKeysNumber = am.loadedKeys.push(k);
    if (loadedKeysNumber > am._cacheSize) {
      var old = am.loadedKeys.pop();
      if (old !== undefined) {
        am.externalPromises.delete(Caml_option.valFromOption(old));
      }
      
    }
    var next = am.loaderQueue.pop();
    if (next !== undefined) {
      return await loadNext(am, Caml_option.valFromOption(next));
    }
    
  };
  var tmp;
  var exit = 0;
  var val;
  try {
    val = await awaitTaskPromiseAndLoadNextWithTimeout();
    exit = 1;
  }
  catch (raw_err){
    var err = Caml_js_exceptions.internalToOCamlException(raw_err);
    var onError = am.onError;
    if (onError !== undefined) {
      onError(am, err);
    }
    await Utils.delay(am._retryDelayMillis);
    tmp = awaitTaskPromiseAndLoadNextWithTimeout();
  }
  if (exit === 1) {
    tmp = Promise.resolve();
  }
  return await tmp;
}

function get(am, k) {
  var x = am.externalPromises.get(k);
  if (x !== undefined) {
    return Caml_option.valFromOption(x);
  }
  var promise = new Promise((function (resolve, param) {
          am.resolvers.set(k, resolve);
        }));
  am.externalPromises.set(k, promise);
  if (am.inProgress.size < am._loaderPoolSize) {
    loadNext(am, k);
  } else {
    am.loaderQueue.push(k);
  }
  return promise;
}

exports.LoaderTimeout = LoaderTimeout;
exports.make = make;
exports.deleteKey = deleteKey;
exports.timeoutAfter = timeoutAfter;
exports.loadNext = loadNext;
exports.get = get;
/* Utils Not a pure module */