Express_Crud_Example/node_modules/mongodb/lib/sdam/topology_description.js
2022-01-28 22:33:42 +01:00

359 lines
17 KiB
JavaScript

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.TopologyDescription = void 0;
const WIRE_CONSTANTS = require("../cmap/wire_protocol/constants");
const error_1 = require("../error");
const utils_1 = require("../utils");
const common_1 = require("./common");
const server_description_1 = require("./server_description");
// constants related to compatibility checks
const MIN_SUPPORTED_SERVER_VERSION = WIRE_CONSTANTS.MIN_SUPPORTED_SERVER_VERSION;
const MAX_SUPPORTED_SERVER_VERSION = WIRE_CONSTANTS.MAX_SUPPORTED_SERVER_VERSION;
const MIN_SUPPORTED_WIRE_VERSION = WIRE_CONSTANTS.MIN_SUPPORTED_WIRE_VERSION;
const MAX_SUPPORTED_WIRE_VERSION = WIRE_CONSTANTS.MAX_SUPPORTED_WIRE_VERSION;
const MONGOS_OR_UNKNOWN = new Set([common_1.ServerType.Mongos, common_1.ServerType.Unknown]);
const MONGOS_OR_STANDALONE = new Set([common_1.ServerType.Mongos, common_1.ServerType.Standalone]);
const NON_PRIMARY_RS_MEMBERS = new Set([
common_1.ServerType.RSSecondary,
common_1.ServerType.RSArbiter,
common_1.ServerType.RSOther
]);
/**
* Representation of a deployment of servers
* @public
*/
class TopologyDescription {
/**
* Create a TopologyDescription
*/
constructor(topologyType, serverDescriptions, setName, maxSetVersion, maxElectionId, commonWireVersion, options) {
var _a, _b;
options = options !== null && options !== void 0 ? options : {};
// TODO: consider assigning all these values to a temporary value `s` which
// we use `Object.freeze` on, ensuring the internal state of this type
// is immutable.
this.type = topologyType !== null && topologyType !== void 0 ? topologyType : common_1.TopologyType.Unknown;
this.servers = serverDescriptions !== null && serverDescriptions !== void 0 ? serverDescriptions : new Map();
this.stale = false;
this.compatible = true;
this.heartbeatFrequencyMS = (_a = options.heartbeatFrequencyMS) !== null && _a !== void 0 ? _a : 0;
this.localThresholdMS = (_b = options.localThresholdMS) !== null && _b !== void 0 ? _b : 0;
if (setName) {
this.setName = setName;
}
if (maxSetVersion) {
this.maxSetVersion = maxSetVersion;
}
if (maxElectionId) {
this.maxElectionId = maxElectionId;
}
if (commonWireVersion) {
this.commonWireVersion = commonWireVersion;
}
// determine server compatibility
for (const serverDescription of this.servers.values()) {
// Load balancer mode is always compatible.
if (serverDescription.type === common_1.ServerType.Unknown ||
serverDescription.type === common_1.ServerType.LoadBalancer) {
continue;
}
if (serverDescription.minWireVersion > MAX_SUPPORTED_WIRE_VERSION) {
this.compatible = false;
this.compatibilityError = `Server at ${serverDescription.address} requires wire version ${serverDescription.minWireVersion}, but this version of the driver only supports up to ${MAX_SUPPORTED_WIRE_VERSION} (MongoDB ${MAX_SUPPORTED_SERVER_VERSION})`;
}
if (serverDescription.maxWireVersion < MIN_SUPPORTED_WIRE_VERSION) {
this.compatible = false;
this.compatibilityError = `Server at ${serverDescription.address} reports wire version ${serverDescription.maxWireVersion}, but this version of the driver requires at least ${MIN_SUPPORTED_WIRE_VERSION} (MongoDB ${MIN_SUPPORTED_SERVER_VERSION}).`;
break;
}
}
// Whenever a client updates the TopologyDescription from a hello response, it MUST set
// TopologyDescription.logicalSessionTimeoutMinutes to the smallest logicalSessionTimeoutMinutes
// value among ServerDescriptions of all data-bearing server types. If any have a null
// logicalSessionTimeoutMinutes, then TopologyDescription.logicalSessionTimeoutMinutes MUST be
// set to null.
this.logicalSessionTimeoutMinutes = undefined;
for (const [, server] of this.servers) {
if (server.isReadable) {
if (server.logicalSessionTimeoutMinutes == null) {
// If any of the servers have a null logicalSessionsTimeout, then the whole topology does
this.logicalSessionTimeoutMinutes = undefined;
break;
}
if (this.logicalSessionTimeoutMinutes == null) {
// First server with a non null logicalSessionsTimeout
this.logicalSessionTimeoutMinutes = server.logicalSessionTimeoutMinutes;
continue;
}
// Always select the smaller of the:
// current server logicalSessionsTimeout and the topologies logicalSessionsTimeout
this.logicalSessionTimeoutMinutes = Math.min(this.logicalSessionTimeoutMinutes, server.logicalSessionTimeoutMinutes);
}
}
}
/**
* Returns a new TopologyDescription based on the SrvPollingEvent
* @internal
*/
updateFromSrvPollingEvent(ev, srvMaxHosts = 0) {
/** The SRV addresses defines the set of addresses we should be using */
const incomingHostnames = ev.hostnames();
const currentHostnames = new Set(this.servers.keys());
const hostnamesToAdd = new Set(incomingHostnames);
const hostnamesToRemove = new Set();
for (const hostname of currentHostnames) {
// filter hostnamesToAdd (made from incomingHostnames) down to what is *not* present in currentHostnames
hostnamesToAdd.delete(hostname);
if (!incomingHostnames.has(hostname)) {
// If the SRV Records no longer include this hostname
// we have to stop using it
hostnamesToRemove.add(hostname);
}
}
if (hostnamesToAdd.size === 0 && hostnamesToRemove.size === 0) {
// No new hosts to add and none to remove
return this;
}
const serverDescriptions = new Map(this.servers);
for (const removedHost of hostnamesToRemove) {
serverDescriptions.delete(removedHost);
}
if (hostnamesToAdd.size > 0) {
if (srvMaxHosts === 0) {
// Add all!
for (const hostToAdd of hostnamesToAdd) {
serverDescriptions.set(hostToAdd, new server_description_1.ServerDescription(hostToAdd));
}
}
else if (serverDescriptions.size < srvMaxHosts) {
// Add only the amount needed to get us back to srvMaxHosts
const selectedHosts = (0, utils_1.shuffle)(hostnamesToAdd, srvMaxHosts - serverDescriptions.size);
for (const selectedHostToAdd of selectedHosts) {
serverDescriptions.set(selectedHostToAdd, new server_description_1.ServerDescription(selectedHostToAdd));
}
}
}
return new TopologyDescription(this.type, serverDescriptions, this.setName, this.maxSetVersion, this.maxElectionId, this.commonWireVersion, { heartbeatFrequencyMS: this.heartbeatFrequencyMS, localThresholdMS: this.localThresholdMS });
}
/**
* Returns a copy of this description updated with a given ServerDescription
* @internal
*/
update(serverDescription) {
const address = serverDescription.address;
// potentially mutated values
let { type: topologyType, setName, maxSetVersion, maxElectionId, commonWireVersion } = this;
if (serverDescription.setName && setName && serverDescription.setName !== setName) {
serverDescription = new server_description_1.ServerDescription(address, undefined);
}
const serverType = serverDescription.type;
const serverDescriptions = new Map(this.servers);
// update common wire version
if (serverDescription.maxWireVersion !== 0) {
if (commonWireVersion == null) {
commonWireVersion = serverDescription.maxWireVersion;
}
else {
commonWireVersion = Math.min(commonWireVersion, serverDescription.maxWireVersion);
}
}
// update the actual server description
serverDescriptions.set(address, serverDescription);
if (topologyType === common_1.TopologyType.Single) {
// once we are defined as single, that never changes
return new TopologyDescription(common_1.TopologyType.Single, serverDescriptions, setName, maxSetVersion, maxElectionId, commonWireVersion, { heartbeatFrequencyMS: this.heartbeatFrequencyMS, localThresholdMS: this.localThresholdMS });
}
if (topologyType === common_1.TopologyType.Unknown) {
if (serverType === common_1.ServerType.Standalone && this.servers.size !== 1) {
serverDescriptions.delete(address);
}
else {
topologyType = topologyTypeForServerType(serverType);
}
}
if (topologyType === common_1.TopologyType.Sharded) {
if (!MONGOS_OR_UNKNOWN.has(serverType)) {
serverDescriptions.delete(address);
}
}
if (topologyType === common_1.TopologyType.ReplicaSetNoPrimary) {
if (MONGOS_OR_STANDALONE.has(serverType)) {
serverDescriptions.delete(address);
}
if (serverType === common_1.ServerType.RSPrimary) {
const result = updateRsFromPrimary(serverDescriptions, serverDescription, setName, maxSetVersion, maxElectionId);
topologyType = result[0];
setName = result[1];
maxSetVersion = result[2];
maxElectionId = result[3];
}
else if (NON_PRIMARY_RS_MEMBERS.has(serverType)) {
const result = updateRsNoPrimaryFromMember(serverDescriptions, serverDescription, setName);
topologyType = result[0];
setName = result[1];
}
}
if (topologyType === common_1.TopologyType.ReplicaSetWithPrimary) {
if (MONGOS_OR_STANDALONE.has(serverType)) {
serverDescriptions.delete(address);
topologyType = checkHasPrimary(serverDescriptions);
}
else if (serverType === common_1.ServerType.RSPrimary) {
const result = updateRsFromPrimary(serverDescriptions, serverDescription, setName, maxSetVersion, maxElectionId);
topologyType = result[0];
setName = result[1];
maxSetVersion = result[2];
maxElectionId = result[3];
}
else if (NON_PRIMARY_RS_MEMBERS.has(serverType)) {
topologyType = updateRsWithPrimaryFromMember(serverDescriptions, serverDescription, setName);
}
else {
topologyType = checkHasPrimary(serverDescriptions);
}
}
return new TopologyDescription(topologyType, serverDescriptions, setName, maxSetVersion, maxElectionId, commonWireVersion, { heartbeatFrequencyMS: this.heartbeatFrequencyMS, localThresholdMS: this.localThresholdMS });
}
get error() {
const descriptionsWithError = Array.from(this.servers.values()).filter((sd) => sd.error);
if (descriptionsWithError.length > 0) {
return descriptionsWithError[0].error;
}
}
/**
* Determines if the topology description has any known servers
*/
get hasKnownServers() {
return Array.from(this.servers.values()).some((sd) => sd.type !== common_1.ServerType.Unknown);
}
/**
* Determines if this topology description has a data-bearing server available.
*/
get hasDataBearingServers() {
return Array.from(this.servers.values()).some((sd) => sd.isDataBearing);
}
/**
* Determines if the topology has a definition for the provided address
* @internal
*/
hasServer(address) {
return this.servers.has(address);
}
}
exports.TopologyDescription = TopologyDescription;
function topologyTypeForServerType(serverType) {
switch (serverType) {
case common_1.ServerType.Standalone:
return common_1.TopologyType.Single;
case common_1.ServerType.Mongos:
return common_1.TopologyType.Sharded;
case common_1.ServerType.RSPrimary:
return common_1.TopologyType.ReplicaSetWithPrimary;
case common_1.ServerType.RSOther:
case common_1.ServerType.RSSecondary:
return common_1.TopologyType.ReplicaSetNoPrimary;
default:
return common_1.TopologyType.Unknown;
}
}
// TODO: improve these docs when ObjectId is properly typed
function compareObjectId(oid1, oid2) {
if (oid1 == null) {
return -1;
}
if (oid2 == null) {
return 1;
}
if (oid1.id instanceof Buffer && oid2.id instanceof Buffer) {
const oid1Buffer = oid1.id;
const oid2Buffer = oid2.id;
return oid1Buffer.compare(oid2Buffer);
}
const oid1String = oid1.toString();
const oid2String = oid2.toString();
return oid1String.localeCompare(oid2String);
}
function updateRsFromPrimary(serverDescriptions, serverDescription, setName, maxSetVersion, maxElectionId) {
setName = setName || serverDescription.setName;
if (setName !== serverDescription.setName) {
serverDescriptions.delete(serverDescription.address);
return [checkHasPrimary(serverDescriptions), setName, maxSetVersion, maxElectionId];
}
const electionId = serverDescription.electionId ? serverDescription.electionId : null;
if (serverDescription.setVersion && electionId) {
if (maxSetVersion && maxElectionId) {
if (maxSetVersion > serverDescription.setVersion ||
compareObjectId(maxElectionId, electionId) > 0) {
// this primary is stale, we must remove it
serverDescriptions.set(serverDescription.address, new server_description_1.ServerDescription(serverDescription.address));
return [checkHasPrimary(serverDescriptions), setName, maxSetVersion, maxElectionId];
}
}
maxElectionId = serverDescription.electionId;
}
if (serverDescription.setVersion != null &&
(maxSetVersion == null || serverDescription.setVersion > maxSetVersion)) {
maxSetVersion = serverDescription.setVersion;
}
// We've heard from the primary. Is it the same primary as before?
for (const [address, server] of serverDescriptions) {
if (server.type === common_1.ServerType.RSPrimary && server.address !== serverDescription.address) {
// Reset old primary's type to Unknown.
serverDescriptions.set(address, new server_description_1.ServerDescription(server.address));
// There can only be one primary
break;
}
}
// Discover new hosts from this primary's response.
serverDescription.allHosts.forEach((address) => {
if (!serverDescriptions.has(address)) {
serverDescriptions.set(address, new server_description_1.ServerDescription(address));
}
});
// Remove hosts not in the response.
const currentAddresses = Array.from(serverDescriptions.keys());
const responseAddresses = serverDescription.allHosts;
currentAddresses
.filter((addr) => responseAddresses.indexOf(addr) === -1)
.forEach((address) => {
serverDescriptions.delete(address);
});
return [checkHasPrimary(serverDescriptions), setName, maxSetVersion, maxElectionId];
}
function updateRsWithPrimaryFromMember(serverDescriptions, serverDescription, setName) {
if (setName == null) {
// TODO(NODE-3483): should be an appropriate runtime error
throw new error_1.MongoRuntimeError('Argument "setName" is required if connected to a replica set');
}
if (setName !== serverDescription.setName ||
(serverDescription.me && serverDescription.address !== serverDescription.me)) {
serverDescriptions.delete(serverDescription.address);
}
return checkHasPrimary(serverDescriptions);
}
function updateRsNoPrimaryFromMember(serverDescriptions, serverDescription, setName) {
const topologyType = common_1.TopologyType.ReplicaSetNoPrimary;
setName = setName || serverDescription.setName;
if (setName !== serverDescription.setName) {
serverDescriptions.delete(serverDescription.address);
return [topologyType, setName];
}
serverDescription.allHosts.forEach((address) => {
if (!serverDescriptions.has(address)) {
serverDescriptions.set(address, new server_description_1.ServerDescription(address));
}
});
if (serverDescription.me && serverDescription.address !== serverDescription.me) {
serverDescriptions.delete(serverDescription.address);
}
return [topologyType, setName];
}
function checkHasPrimary(serverDescriptions) {
for (const serverDescription of serverDescriptions.values()) {
if (serverDescription.type === common_1.ServerType.RSPrimary) {
return common_1.TopologyType.ReplicaSetWithPrimary;
}
}
return common_1.TopologyType.ReplicaSetNoPrimary;
}
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