ethers.js/packages/providers/fallback-provider.js
2019-08-22 17:12:51 -04:00

318 lines
14 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 __());
};
})();
Object.defineProperty(exports, "__esModule", { value: true });
var random_1 = require("@ethersproject/random");
var properties_1 = require("@ethersproject/properties");
var logger_1 = require("@ethersproject/logger");
var _version_1 = require("./_version");
var logger = new logger_1.Logger(_version_1.version);
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;
}
logger.throwArgumentError("provider mismatch", "networks", 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 keys = Object.keys(result);
keys.sort();
return "{" + keys.map(function (key) {
var value = result[key];
if (typeof (value) === "function") {
value = "function{}";
}
else {
value = serialize(value);
}
return JSON.stringify(key) + "=" + serialize(value);
}).join(",") + "}";
}
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;
logger.checkNew(_newTarget, FallbackProvider);
if (providers.length === 0) {
logger.throwArgumentError("missing providers", "providers", providers);
}
if (weights != null && weights.length !== providers.length) {
logger.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) {
logger.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) {
logger.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)) {
logger.throwError("getNetwork returned null", logger_1.Logger.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.doPerform = function (provider, method, params) {
switch (method) {
case "getBlockNumber":
case "getGasPrice":
case "getEtherPrice":
return provider[method]();
case "getBalance":
case "getTransactionCount":
case "getCode":
return provider[method](params.address, params.blockTag || "latest");
case "getStorageAt":
return provider.getStorageAt(params.address, params.position, params.blockTag || "latest");
case "sendTransaction":
return provider.sendTransaction(params.signedTransaction).then(function (result) {
return result.hash;
});
case "getBlock":
return provider[(params.includeTransactions ? "getBlockWithTransactions" : "getBlock")](params.blockTag || params.blockHash);
case "call":
case "estimateGas":
return provider[method](params.transaction);
case "getTransaction":
case "getTransactionReceipt":
return provider[method](params.transactionHash);
case "getLogs":
return provider.getLogs(params.filter);
}
return logger.throwError("unknown method error", logger_1.Logger.errors.UNKNOWN_ERROR, {
method: method,
params: params
});
};
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", {
action: "request",
rid: rid,
backend: { weight: weight, start: start, provider: provider },
request: { method: method, params: properties_1.deepCopy(params) },
provider: _this
});
return FallbackProvider.doPerform(provider, method, params).then(function (result) {
var duration = now() - t0;
_this.emit("debug", {
action: "response",
rid: rid,
backend: { weight: weight, start: start, duration: duration, provider: provider },
request: { method: method, params: properties_1.deepCopy(params) },
response: properties_1.deepCopy(result)
});
return { weight: weight, result: result };
}, function (error) {
var duration = now() - t0;
_this.emit("debug", {
action: "response",
rid: rid,
backend: { weight: weight, start: start, duration: duration, provider: provider },
request: { method: method, params: properties_1.deepCopy(params) },
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) {
// @TODO: this might need some more thinking... Maybe only if half
// of the results contain non-error?
if (method === "getGasPrice") {
var values_1 = [];
Object.keys(results).forEach(function (key) {
results[key].forEach(function (result) {
if (!result.result) {
return;
}
values_1.push(result.result);
});
});
values_1.sort(function (a, b) {
if (a.lt(b)) {
return -1;
}
if (a.gt(b)) {
return 1;
}
return 0;
});
var index = parseInt(String(values_1.length / 2));
if (values_1.length % 2) {
resolve(values_1[index]);
return;
}
resolve(values_1[index - 1].add(values_1[index]).div(2));
return;
}
if (firstError === null) {
firstError = logger.makeError("failed to meet quorum", logger_1.Logger.errors.SERVER_ERROR, {
results: Object.keys(results).map(function (u) {
return {
method: method,
params: params,
result: u,
weight: results[u].reduce(function (accum, r) { return (accum + r.weight); }, 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;