ethers.js/packages/providers/fallback-provider.js
2019-05-14 18:48:48 -04:00

231 lines
9.3 KiB
JavaScript

"use strict";
var __extends = (this && this.__extends) || (function () {
var extendStatics = function (d, b) {
extendStatics = Object.setPrototypeOf ||
({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
return extendStatics(d, b);
};
return function (d, b) {
extendStatics(d, b);
function __() { this.constructor = d; }
d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
};
})();
var __importStar = (this && this.__importStar) || function (mod) {
if (mod && mod.__esModule) return mod;
var result = {};
if (mod != null) for (var k in mod) if (Object.hasOwnProperty.call(mod, k)) result[k] = mod[k];
result["default"] = mod;
return result;
};
Object.defineProperty(exports, "__esModule", { value: true });
var errors = __importStar(require("@ethersproject/errors"));
var random_1 = require("@ethersproject/random");
var properties_1 = require("@ethersproject/properties");
var base_provider_1 = require("./base-provider");
function now() { return (new Date()).getTime(); }
// Returns:
// - true is all networks match
// - false if any network is null
// - throws if any 2 networks do not match
function checkNetworks(networks) {
var result = true;
var check = null;
networks.forEach(function (network) {
// Null
if (network == null) {
result = false;
return;
}
// Have nothing to compre to yet
if (check == null) {
check = network;
return;
}
// Matches!
if (check.name === network.name &&
check.chainId === network.chainId &&
((check.ensAddress === network.ensAddress) ||
(check.ensAddress == null && network.ensAddress == null))) {
return;
}
errors.throwError("provider mismatch", errors.INVALID_ARGUMENT, { arg: "networks", value: networks });
});
return result;
}
function serialize(result) {
if (Array.isArray(result)) {
return JSON.stringify(result.map(function (r) { return serialize(r); }));
}
else if (result === null) {
return "null";
}
else if (typeof (result) === "object") {
var bare_1 = {};
var keys = Object.keys(result);
keys.sort();
keys.forEach(function (key) {
var value = result[key];
if (typeof (value) === "function") {
return;
}
bare_1[key] = serialize(value);
});
return JSON.stringify(bare_1);
}
return JSON.stringify(result);
}
var nextRid = 1;
var FallbackProvider = /** @class */ (function (_super) {
__extends(FallbackProvider, _super);
function FallbackProvider(providers, quorum, weights) {
var _newTarget = this.constructor;
var _this = this;
errors.checkNew(_newTarget, FallbackProvider);
if (providers.length === 0) {
errors.throwArgumentError("missing providers", "providers", providers);
}
if (weights != null && weights.length !== providers.length) {
errors.throwArgumentError("too many weights", "weights", weights);
}
else if (!weights) {
weights = providers.map(function (p) { return 1; });
}
else {
weights.forEach(function (w) {
if (w % 1 || w > 512 || w < 1) {
errors.throwArgumentError("invalid weight; must be integer in [1, 512]", "weights", weights);
}
});
}
var total = weights.reduce(function (accum, w) { return (accum + w); });
if (quorum == null) {
quorum = total / 2;
}
else {
if (quorum > total) {
errors.throwArgumentError("quorum will always fail; larger than total weight", "quorum", quorum);
}
}
// All networks are ready, we can know the network for certain
var ready = checkNetworks(providers.map(function (p) { return p.network; }));
if (ready) {
_this = _super.call(this, providers[0].network) || this;
}
else {
// The network won't be known until all child providers know
var ready_1 = Promise.all(providers.map(function (p) { return p.getNetwork(); })).then(function (networks) {
if (!checkNetworks(networks)) {
errors.throwError("getNetwork returned null", errors.UNKNOWN_ERROR, {});
}
return networks[0];
});
_this = _super.call(this, ready_1) || this;
}
// Preserve a copy, so we do not get mutated
properties_1.defineReadOnly(_this, "providers", Object.freeze(providers.slice()));
properties_1.defineReadOnly(_this, "quorum", quorum);
properties_1.defineReadOnly(_this, "weights", Object.freeze(weights.slice()));
return _this;
}
FallbackProvider.prototype.perform = function (method, params) {
var _this = this;
var T0 = now();
var runners = (random_1.shuffled(this.providers)).map(function (provider, i) {
var weight = _this.weights[i];
var rid = nextRid++;
return {
run: function () {
var t0 = now();
var start = t0 - T0;
_this.emit("debug", "perform", rid, { weight: weight, start: start, provider: provider, method: method, params: params });
return provider.perform(method, params).then(function (result) {
var duration = now() - t0;
_this.emit("debug", "result", rid, { duration: duration, result: result });
return { weight: weight, result: result };
}, function (error) {
var duration = now() - t0;
_this.emit("debug", "error", rid, { duration: duration, error: error });
return { weight: weight, error: error };
});
},
weight: weight
};
});
// Broadcast transactions to all backends, any that succeed is good enough
if (method === "sendTransaction") {
return Promise.all(runners.map(function (r) { return r.run(); })).then(function (results) {
for (var i = 0; i < results.length; i++) {
var result = results[i];
if (result.result) {
return result.result;
}
}
return Promise.reject(results[0].error);
});
}
// Otherwise query backends (randomly) until we have a quorum agreement
// on the correct result
return new Promise(function (resolve, reject) {
var firstError = null;
// How much weight is inflight
var inflightWeight = 0;
// All results, indexed by the serialized response.
var results = {};
var next = function () {
if (runners.length === 0) {
return;
}
var runner = runners.shift();
inflightWeight += runner.weight;
runner.run().then(function (result) {
if (results === null) {
return;
}
inflightWeight -= runner.weight;
if (result.error) {
if (firstError == null) {
firstError = result.error;
}
}
else {
var unique = serialize(result.result);
if (results[unique] == null) {
results[unique] = [];
}
results[unique].push(result);
// Do any results meet our quroum?
for (var u in results) {
var weight = results[u].reduce(function (accum, r) { return (accum + r.weight); }, 0);
if (weight >= _this.quorum) {
var result_1 = results[u][0].result;
_this.emit("debug", "quorum", -1, { weight: weight, result: result_1 });
resolve(result_1);
results = null;
return;
}
}
}
// Out of options; give up
if (runners.length === 0 && inflightWeight === 0) {
reject(firstError);
return;
}
// Queue up the next round
setTimeout(next, 0);
});
// Fire off requests until we could possibly meet quorum
if (inflightWeight < _this.quorum) {
setTimeout(next, 0);
return;
}
};
// bootstrap firing requests
next();
});
};
return FallbackProvider;
}(base_provider_1.BaseProvider));
exports.FallbackProvider = FallbackProvider;