import { ActionBundle, ActionInfo, Envelope, getEnvContent, LocalActionBundle, UserActionBundle } from 'app/common/ActionBundle'; import {DocAction, getNumRows, UserAction} from 'app/common/DocActions'; import {allToken} from 'app/common/sharing'; import * as log from 'app/server/lib/log'; import {LogMethods} from "app/server/lib/LogMethods"; import {shortDesc} from 'app/server/lib/shortDesc'; import * as assert from 'assert'; import {Mutex} from 'async-mutex'; import * as Deque from 'double-ended-queue'; import {ActionHistory, asActionGroup, getActionUndoInfo} from './ActionHistory'; import {ActiveDoc} from './ActiveDoc'; import {makeExceptionalDocSession, OptDocSession} from './DocSession'; import {WorkCoordinator} from './WorkCoordinator'; // Describes the request to apply a UserActionBundle. It includes a Client (so that broadcast // message can set `.fromSelf` property), and methods to resolve or reject the promise for when // the action is applied. Note that it may not be immediate in case we are in the middle of // processing hub actions or rebasing. interface UserRequest { action: UserActionBundle; docSession: OptDocSession|null; resolve(result: UserResult): void; reject(err: Error): void; } // The result of applying a UserRequest, used to resolve the promise. It includes the retValues // (one for each UserAction in the bundle) and the actionNum of the applied LocalActionBundle. interface UserResult { actionNum: number; retValues: any[]; isModification: boolean; } // Internally-used enum to distinguish if applied actions should be logged as local or shared. enum Branch { Local, Shared } // Don't log details of action bundles in production. const LOG_ACTION_BUNDLE = (process.env.NODE_ENV !== 'production'); export class Sharing { protected _activeDoc: ActiveDoc; protected _actionHistory: ActionHistory; protected _hubQueue: Deque = new Deque(); protected _pendingQueue: Deque = new Deque(); protected _workCoordinator: WorkCoordinator; private _log = new LogMethods('Sharing ', (s: OptDocSession|null) => this._activeDoc.getLogMeta(s)); constructor(activeDoc: ActiveDoc, actionHistory: ActionHistory, private _modificationLock: Mutex) { // TODO actionHistory is currently unused (we use activeDoc.actionLog). assert(actionHistory.isInitialized()); this._activeDoc = activeDoc; this._actionHistory = actionHistory; this._workCoordinator = new WorkCoordinator(() => this._doNextStep()); } /** * Returns whether this doc is shared. It's shared if and only if HubDocClient is set (though it * may be disconnected). */ public isShared(): boolean { return false; } public isSharingActivated(): boolean { return false; } /** Returns the instanceId if the doc is shared or null otherwise. */ public get instanceId(): string|null { return null; } public isOwnEnvelope(recipients: string[]): boolean { return true; } public async sendLocalAction(): Promise { throw new Error('sendLocalAction not implemented'); } public async removeInstanceFromDoc(): Promise { throw new Error('removeInstanceFromDoc not implemented'); } /** * The only public interface. This may be called at any time, including while rebasing. * WorkCoordinator ensures that actual work will only happen once other work finishes. */ public addUserAction(userRequest: UserRequest) { this._pendingQueue.push(userRequest); this._workCoordinator.ping(); } // Returns a promise if there is some work happening, or null if there isn't. private _doNextStep(): Promise|null { if (this._hubQueue.isEmpty()) { if (!this._pendingQueue.isEmpty()) { return this._applyLocalAction(); } else if (this.isSharingActivated() && this._actionHistory.haveLocalUnsent()) { return this.sendLocalAction(); } else { return null; } } else { if (!this._actionHistory.haveLocalActions()) { return this._applyHubAction(); } else { return this._mergeInHubAction(); } } } private async _applyLocalAction(): Promise { assert(this._hubQueue.isEmpty() && !this._pendingQueue.isEmpty()); const userRequest: UserRequest = this._pendingQueue.shift()!; try { const ret = await this._doApplyUserActionBundle(userRequest.action, userRequest.docSession); userRequest.resolve(ret); } catch (e) { this._log.warn(userRequest.docSession, "Unable to apply action...", e); userRequest.reject(e); } } private async _applyHubAction(): Promise { assert(!this._hubQueue.isEmpty() && !this._actionHistory.haveLocalActions()); const action: ActionBundle = this._hubQueue.shift()!; try { await this._doApplySharedActionBundle(action); } catch (e) { this._log.error(null, "Unable to apply hub action... skipping"); } } private async _mergeInHubAction(): Promise { assert(!this._hubQueue.isEmpty() && this._actionHistory.haveLocalActions()); const action: ActionBundle = this._hubQueue.peekFront()!; try { const accepted = await this._actionHistory.acceptNextSharedAction(action.actionHash); if (accepted) { this._hubQueue.shift(); } else { await this._rebaseLocalActions(); } } catch (e) { this._log.error(null, "Unable to apply hub action... skipping"); } } private async _rebaseLocalActions(): Promise { const rebaseQueue: Deque = new Deque(); try { this._createCheckpoint(); const actions: LocalActionBundle[] = await this._actionHistory.fetchAllLocal(); assert(actions.length > 0); await this._doApplyUserActionBundle(this._createUndo(actions), null); rebaseQueue.push(...actions.map((a) => getUserActionBundle(a))); await this._actionHistory.clearLocalActions(); } catch (e) { this._log.error(null, "Can't undo local actions; sharing is off"); this._rollbackToCheckpoint(); // TODO this.disconnect(); // TODO errorState = true; return; } assert(!this._actionHistory.haveLocalActions()); while (!this._hubQueue.isEmpty()) { await this._applyHubAction(); } const rebaseFailures: Array<[UserActionBundle, UserActionBundle]> = []; while (!rebaseQueue.isEmpty()) { const action: UserActionBundle = rebaseQueue.shift()!; const adjusted: UserActionBundle = this._mergeAdjust(action); try { await this._doApplyUserActionBundle(adjusted, null); } catch (e) { this._log.warn(null, "Unable to apply rebased action..."); rebaseFailures.push([action, adjusted]); } } if (rebaseFailures.length > 0) { this._createBackupAtCheckpoint(); // TODO we should notify the user too. this._log.error(null, 'Rebase failed to reapply some of your actions, backup of local at...'); } this._releaseCheckpoint(); } // ====================================================================== private _doApplySharedActionBundle(action: ActionBundle): Promise { const userActions: UserAction[] = [ ['ApplyDocActions', action.stored.map(envContent => envContent[1])] ]; return this._doApplyUserActions(action.info[1], userActions, Branch.Shared, null); } private _doApplyUserActionBundle(action: UserActionBundle, docSession: OptDocSession|null): Promise { return this._doApplyUserActions(action.info, action.userActions, Branch.Local, docSession); } private async _doApplyUserActions(info: ActionInfo, userActions: UserAction[], branch: Branch, docSession: OptDocSession|null): Promise { const client = docSession && docSession.client; if (docSession?.linkId) { info.linkId = docSession.linkId; } const {sandboxActionBundle, undo, accessControl} = await this._modificationLock.runExclusive(() => this._applyActionsToDataEngine(docSession, userActions)); try { const isCalculate = (userActions.length === 1 && (userActions[0][0] === 'Calculate' || userActions[0][0] === 'UpdateCurrentTime')); // `internal` is true if users shouldn't be able to undo the actions. Applies to: // - Calculate/UpdateCurrentTime because it's not considered as performed by a particular client. // - Adding attachment metadata when uploading attachments, // because then the attachment file may get hard-deleted and redo won't work properly. const internal = isCalculate || userActions.every(a => a[0] === "AddRecord" && a[1] === "_grist_Attachments"); // A trivial action does not merit allocating an actionNum, // logging, and sharing. It's best not to log the // action that calculates formula values when the document is opened cold // (without cached ActiveDoc) if it doesn't change anything - otherwise we'll end up with spam // log entries for each time the document is opened cold. const trivial = internal && sandboxActionBundle.stored.length === 0; const actionNum = trivial ? 0 : (branch === Branch.Shared ? this._actionHistory.getNextHubActionNum() : this._actionHistory.getNextLocalActionNum()); const localActionBundle: LocalActionBundle = { actionNum, // The ActionInfo should go into the envelope that includes all recipients. info: [findOrAddAllEnvelope(sandboxActionBundle.envelopes), info], envelopes: sandboxActionBundle.envelopes, stored: sandboxActionBundle.stored, calc: sandboxActionBundle.calc, undo, userActions, actionHash: null, // Gets set below by _actionHistory.recordNext... parentActionHash: null, // Gets set below by _actionHistory.recordNext... }; const altSessionId = client?.getAltSessionId(); const logMeta = { actionNum, linkId: info.linkId, otherId: info.otherId, numDocActions: localActionBundle.stored.length, numRows: localActionBundle.stored.reduce((n, env) => n + getNumRows(env[1]), 0), author: info.user, ...(altSessionId ? {session: altSessionId}: {}), }; this._log.rawLog('debug', docSession, '_doApplyUserActions', logMeta); if (LOG_ACTION_BUNDLE) { this._logActionBundle(`_doApplyUserActions (${Branch[branch]})`, localActionBundle); } // TODO Note that the sandbox may produce actions which are not addressed to us (e.g. when we // have EDIT permission without VIEW). These are not sent to the browser or the database. But // today they are reflected in the sandbox. Should we (or the sandbox) immediately undo the // full change, and then redo only the actions addressed to ourselves? Let's cross that bridge // when we come to it. For now we only log skipped envelopes as "alien" in _logActionBundle(). const ownActionBundle: LocalActionBundle = this._filterOwnActions(localActionBundle); // If the document has shut down in the meantime, and this was just a "Calculate" action, // return a trivial result. This is just to reduce noisy warnings in migration tests. if (this._activeDoc.isShuttingDown && isCalculate) { return { actionNum: localActionBundle.actionNum, retValues: [], isModification: false }; } // Apply the action to the database, and record in the action log. if (!trivial) { await this._activeDoc.docStorage.execTransaction(async () => { await this._activeDoc.docStorage.applyStoredActions(getEnvContent(ownActionBundle.stored)); if (this.isShared() && branch === Branch.Local) { // this call will compute an actionHash for localActionBundle await this._actionHistory.recordNextLocalUnsent(localActionBundle); } else { // Before sharing is enabled, actions are immediately marked as "shared" (as if accepted // by the hub). The alternative of keeping actions on the "local" branch until sharing is // enabled is less suitable, because such actions could have empty envelopes, and cannot // be shared. Once sharing is enabled, we would share a snapshot at that time. await this._actionHistory.recordNextShared(localActionBundle); } if (client && client.clientId && !internal) { this._actionHistory.setActionUndoInfo( localActionBundle.actionHash!, getActionUndoInfo(localActionBundle, client.clientId, sandboxActionBundle.retValues)); } }); } await this._activeDoc.processActionBundle(ownActionBundle); const actionSummary = await this._activeDoc.handleTriggers(localActionBundle); await this._activeDoc.updateRowCount(sandboxActionBundle.rowCount, docSession); // Broadcast the action to connected browsers. const actionGroup = asActionGroup(this._actionHistory, localActionBundle, { clientId: client?.clientId, retValues: sandboxActionBundle.retValues, internal, }); actionGroup.actionSummary = actionSummary; await accessControl.appliedBundle(); await accessControl.sendDocUpdateForBundle(actionGroup, this._activeDoc.getDocUsageSummary()); if (docSession) { docSession.linkId = docSession.shouldBundleActions ? localActionBundle.actionNum : 0; } return { actionNum: localActionBundle.actionNum, retValues: sandboxActionBundle.retValues, isModification: sandboxActionBundle.stored.length > 0 }; } finally { // Make sure the bundle is marked as complete, even if some miscellaneous error occurred. await accessControl.finishedBundle(); } } private _mergeAdjust(action: UserActionBundle): UserActionBundle { // TODO: This is where we adjust actions after rebase, e.g. add delta to rowIds and such. return action; } /** * Creates a UserActionBundle with a single 'ApplyUndoActions' action, which combines the undo * actions addressed to ourselves from all of the passed-in LocalActionBundles. */ private _createUndo(localActions: LocalActionBundle[]): UserActionBundle { assert(localActions.length > 0); const undo: DocAction[] = []; for (const local of localActions) { undo.push(...local.undo); } const first = localActions[0]; return { info: { time: Date.now(), user: first.info[1].user, inst: first.info[1].inst, desc: "UNDO BEFORE REBASE", otherId: 0, linkId: 0, }, userActions: [['ApplyUndoActions', undo]] }; } // Our beautiful little checkpointing interface, used to handle errors during rebase. private _createCheckpoint() { /* TODO */ } private _releaseCheckpoint() { /* TODO */ } private _rollbackToCheckpoint() { /* TODO */ } private _createBackupAtCheckpoint() { /* TODO */ } /** * Reduces a LocalActionBundle down to only those actions addressed to ourselves. */ private _filterOwnActions(localActionBundle: LocalActionBundle): LocalActionBundle { const includeEnv: boolean[] = localActionBundle.envelopes.map( (e) => this.isOwnEnvelope(e.recipients)); return Object.assign({}, localActionBundle, { stored: localActionBundle.stored.filter((ea) => includeEnv[ea[0]]), calc: localActionBundle.calc.filter((ea) => includeEnv[ea[0]]), }); } /** Log an action bundle to the debug log. */ private _logActionBundle(prefix: string, actionBundle: ActionBundle) { const includeEnv = actionBundle.envelopes.map((e) => this.isOwnEnvelope(e.recipients)); actionBundle.stored.forEach((envAction, i) => log.debug("%s: stored #%s [%s%s]: %s", prefix, i, envAction[0], (includeEnv[envAction[0]] ? "" : " alien"), shortDesc(envAction[1]))); actionBundle.calc.forEach((envAction, i) => log.debug("%s: calc #%s [%s%s]: %s", prefix, i, envAction[0], (includeEnv[envAction[0]] ? "" : " alien"), shortDesc(envAction[1]))); } private async _applyActionsToDataEngine(docSession: OptDocSession|null, userActions: UserAction[]) { const sandboxActionBundle = await this._activeDoc.applyActionsToDataEngine(docSession, userActions); const undo = getEnvContent(sandboxActionBundle.undo); const docActions = getEnvContent(sandboxActionBundle.stored).concat( getEnvContent(sandboxActionBundle.calc)); const isDirect = getEnvContent(sandboxActionBundle.direct); const accessControl = this._activeDoc.getGranularAccessForBundle( docSession || makeExceptionalDocSession('share'), docActions, undo, userActions, isDirect ); try { // TODO: see if any of the code paths that have no docSession are relevant outside // of tests. await accessControl.canApplyBundle(); } catch (e) { // should not commit. Don't write to db. Remove changes from sandbox. try { await this._activeDoc.applyActionsToDataEngine(docSession, [['ApplyUndoActions', undo]]); } finally { await accessControl.finishedBundle(); } throw e; } return {sandboxActionBundle, undo, docActions, accessControl}; } } /** * Returns the index of the envelope containing the '#ALL' recipient, adding such an envelope to * the provided array if it wasn't already there. */ export function findOrAddAllEnvelope(envelopes: Envelope[]): number { const i = envelopes.findIndex(e => e.recipients.includes(allToken)); if (i >= 0) { return i; } envelopes.push({recipients: [allToken]}); return envelopes.length - 1; } /** * Extract a UserActionBundle from a LocalActionBundle, which contains a superset of data. */ function getUserActionBundle(localAction: LocalActionBundle): UserActionBundle { return { info: localAction.info[1], userActions: localAction.userActions }; }