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migrate to use ot.js

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Signed-off-by: Raccoon <raccoon@hackmd.io>
This commit is contained in:
Raccoon 2021-06-12 08:18:35 +08:00
parent 8ba97c36df
commit b0b079a33a
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12 changed files with 7 additions and 1453 deletions
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2
lib/models/note.ts
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@ -18,7 +18,7 @@ import * as logger from "../logger";
import {stripTags} from "../string";
// ot
import * as ot from "../ot";
import * as ot from "ot";
var md = markdown_it()
var dmp = new DiffMatchPatch()

312
lib/ot/client.js
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@ -1,312 +0,0 @@
// translation of https://github.com/djspiewak/cccp/blob/master/agent/src/main/scala/com/codecommit/cccp/agent/state.scala
if (typeof ot === 'undefined') {
var ot = {};
}
ot.Client = (function (global) {
'use strict';
// Client constructor
function Client (revision) {
this.revision = revision; // the next expected revision number
this.setState(synchronized_); // start state
}
Client.prototype.setState = function (state) {
this.state = state;
};
// Call this method when the user changes the document.
Client.prototype.applyClient = function (operation) {
this.setState(this.state.applyClient(this, operation));
};
// Call this method with a new operation from the server
Client.prototype.applyServer = function (revision, operation) {
this.setState(this.state.applyServer(this, revision, operation));
};
Client.prototype.applyOperations = function (head, operations) {
this.setState(this.state.applyOperations(this, head, operations));
};
Client.prototype.serverAck = function (revision) {
this.setState(this.state.serverAck(this, revision));
};
Client.prototype.serverReconnect = function () {
if (typeof this.state.resend === 'function') { this.state.resend(this); }
};
// Transforms a selection from the latest known server state to the current
// client state. For example, if we get from the server the information that
// another user's cursor is at position 3, but the server hasn't yet received
// our newest operation, an insertion of 5 characters at the beginning of the
// document, the correct position of the other user's cursor in our current
// document is 8.
Client.prototype.transformSelection = function (selection) {
return this.state.transformSelection(selection);
};
// Override this method.
Client.prototype.sendOperation = function (revision, operation) {
throw new Error("sendOperation must be defined in child class");
};
// Override this method.
Client.prototype.applyOperation = function (operation) {
throw new Error("applyOperation must be defined in child class");
};
// In the 'Synchronized' state, there is no pending operation that the client
// has sent to the server.
function Synchronized () {}
Client.Synchronized = Synchronized;
Synchronized.prototype.applyClient = function (client, operation) {
// When the user makes an edit, send the operation to the server and
// switch to the 'AwaitingConfirm' state
client.sendOperation(client.revision, operation);
return new AwaitingConfirm(operation);
};
Synchronized.prototype.applyServer = function (client, revision, operation) {
if (revision - client.revision > 1) {
throw new Error("Invalid revision.");
}
client.revision = revision;
// When we receive a new operation from the server, the operation can be
// simply applied to the current document
client.applyOperation(operation);
return this;
};
Synchronized.prototype.serverAck = function (client, revision) {
throw new Error("There is no pending operation.");
};
// Nothing to do because the latest server state and client state are the same.
Synchronized.prototype.transformSelection = function (x) { return x; };
// Singleton
var synchronized_ = new Synchronized();
// In the 'AwaitingConfirm' state, there's one operation the client has sent
// to the server and is still waiting for an acknowledgement.
function AwaitingConfirm (outstanding) {
// Save the pending operation
this.outstanding = outstanding;
}
Client.AwaitingConfirm = AwaitingConfirm;
AwaitingConfirm.prototype.applyClient = function (client, operation) {
// When the user makes an edit, don't send the operation immediately,
// instead switch to 'AwaitingWithBuffer' state
return new AwaitingWithBuffer(this.outstanding, operation);
};
AwaitingConfirm.prototype.applyServer = function (client, revision, operation) {
if (revision - client.revision > 1) {
throw new Error("Invalid revision.");
}
client.revision = revision;
// This is another client's operation. Visualization:
//
// /\
// this.outstanding / \ operation
// / \
// \ /
// pair[1] \ / pair[0] (new outstanding)
// (can be applied \/
// to the client's
// current document)
var pair = operation.constructor.transform(this.outstanding, operation);
client.applyOperation(pair[1]);
return new AwaitingConfirm(pair[0]);
};
AwaitingConfirm.prototype.serverAck = function (client, revision) {
if (revision - client.revision > 1) {
return new Stale(this.outstanding, client, revision).getOperations();
}
client.revision = revision;
// The client's operation has been acknowledged
// => switch to synchronized state
return synchronized_;
};
AwaitingConfirm.prototype.transformSelection = function (selection) {
return selection.transform(this.outstanding);
};
AwaitingConfirm.prototype.resend = function (client) {
// The confirm didn't come because the client was disconnected.
// Now that it has reconnected, we resend the outstanding operation.
client.sendOperation(client.revision, this.outstanding);
};
// In the 'AwaitingWithBuffer' state, the client is waiting for an operation
// to be acknowledged by the server while buffering the edits the user makes
function AwaitingWithBuffer (outstanding, buffer) {
// Save the pending operation and the user's edits since then
this.outstanding = outstanding;
this.buffer = buffer;
}
Client.AwaitingWithBuffer = AwaitingWithBuffer;
AwaitingWithBuffer.prototype.applyClient = function (client, operation) {
// Compose the user's changes onto the buffer
var newBuffer = this.buffer.compose(operation);
return new AwaitingWithBuffer(this.outstanding, newBuffer);
};
AwaitingWithBuffer.prototype.applyServer = function (client, revision, operation) {
if (revision - client.revision > 1) {
throw new Error("Invalid revision.");
}
client.revision = revision;
// Operation comes from another client
//
// /\
// this.outstanding / \ operation
// / \
// /\ /
// this.buffer / \* / pair1[0] (new outstanding)
// / \/
// \ /
// pair2[1] \ / pair2[0] (new buffer)
// the transformed \/
// operation -- can
// be applied to the
// client's current
// document
//
// * pair1[1]
var transform = operation.constructor.transform;
var pair1 = transform(this.outstanding, operation);
var pair2 = transform(this.buffer, pair1[1]);
client.applyOperation(pair2[1]);
return new AwaitingWithBuffer(pair1[0], pair2[0]);
};
AwaitingWithBuffer.prototype.serverAck = function (client, revision) {
if (revision - client.revision > 1) {
return new StaleWithBuffer(this.outstanding, this.buffer, client, revision).getOperations();
}
client.revision = revision;
// The pending operation has been acknowledged
// => send buffer
client.sendOperation(client.revision, this.buffer);
return new AwaitingConfirm(this.buffer);
};
AwaitingWithBuffer.prototype.transformSelection = function (selection) {
return selection.transform(this.outstanding).transform(this.buffer);
};
AwaitingWithBuffer.prototype.resend = function (client) {
// The confirm didn't come because the client was disconnected.
// Now that it has reconnected, we resend the outstanding operation.
client.sendOperation(client.revision, this.outstanding);
};
function Stale(acknowlaged, client, revision) {
this.acknowlaged = acknowlaged;
this.client = client;
this.revision = revision;
}
Client.Stale = Stale;
Stale.prototype.applyClient = function (client, operation) {
return new StaleWithBuffer(this.acknowlaged, operation, client, this.revision);
};
Stale.prototype.applyServer = function (client, revision, operation) {
throw new Error("Ignored server-side change.");
};
Stale.prototype.applyOperations = function (client, head, operations) {
var transform = this.acknowlaged.constructor.transform;
for (var i = 0; i < operations.length; i++) {
var op = ot.TextOperation.fromJSON(operations[i]);
var pair = transform(this.acknowlaged, op);
client.applyOperation(pair[1]);
this.acknowlaged = pair[0];
}
client.revision = this.revision;
return synchronized_;
};
Stale.prototype.serverAck = function (client, revision) {
throw new Error("There is no pending operation.");
};
Stale.prototype.transformSelection = function (selection) {
return selection;
};
Stale.prototype.getOperations = function () {
this.client.getOperations(this.client.revision, this.revision - 1); // acknowlaged is the one at revision
return this;
};
function StaleWithBuffer(acknowlaged, buffer, client, revision) {
this.acknowlaged = acknowlaged;
this.buffer = buffer;
this.client = client;
this.revision = revision;
}
Client.StaleWithBuffer = StaleWithBuffer;
StaleWithBuffer.prototype.applyClient = function (client, operation) {
var buffer = this.buffer.compose(operation);
return new StaleWithBuffer(this.acknowlaged, buffer, client, this.revision);
};
StaleWithBuffer.prototype.applyServer = function (client, revision, operation) {
throw new Error("Ignored server-side change.");
};
StaleWithBuffer.prototype.applyOperations = function (client, head, operations) {
var transform = this.acknowlaged.constructor.transform;
for (var i = 0; i < operations.length; i++) {
var op = ot.TextOperation.fromJSON(operations[i]);
var pair1 = transform(this.acknowlaged, op);
var pair2 = transform(this.buffer, pair1[1]);
client.applyOperation(pair2[1]);
this.acknowlaged = pair1[0];
this.buffer = pair2[0];
}
client.revision = this.revision;
client.sendOperation(client.revision, this.buffer);
return new AwaitingConfirm(this.buffer);
};
StaleWithBuffer.prototype.serverAck = function (client, revision) {
throw new Error("There is no pending operation.");
};
StaleWithBuffer.prototype.transformSelection = function (selection) {
return selection;
};
StaleWithBuffer.prototype.getOperations = function () {
this.client.getOperations(this.client.revision, this.revision - 1); // acknowlaged is the one at revision
return this;
};
return Client;
}(this));
if (typeof module === 'object') {
module.exports = ot.Client;
}

164
lib/ot/editor-socketio-server.js
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@ -1,164 +0,0 @@
'use strict';
var EventEmitter = require('events').EventEmitter;
var TextOperation = require('./text-operation');
var WrappedOperation = require('./wrapped-operation');
var Server = require('./server');
var Selection = require('./selection');
var util = require('util');
var logger = require('../logger');
function EditorSocketIOServer(document, operations, docId, mayWrite, operationCallback) {
EventEmitter.call(this);
Server.call(this, document, operations);
this.users = {};
this.docId = docId;
this.mayWrite = mayWrite || function (_, cb) {
cb(true);
};
this.operationCallback = operationCallback;
}
util.inherits(EditorSocketIOServer, Server);
extend(EditorSocketIOServer.prototype, EventEmitter.prototype);
function extend(target, source) {
for (var key in source) {
if (source.hasOwnProperty(key)) {
target[key] = source[key];
}
}
}
EditorSocketIOServer.prototype.addClient = function (socket) {
var self = this;
socket.join(this.docId);
var docOut = {
str: this.document,
revision: this.operations.length,
clients: this.users
};
socket.emit('doc', docOut);
socket.on('operation', function (revision, operation, selection) {
socket.origin = 'operation';
self.mayWrite(socket, function (mayWrite) {
if (!mayWrite) {
logger.info("User doesn't have the right to edit.");
return;
}
try {
self.onOperation(socket, revision, operation, selection);
if (typeof self.operationCallback === 'function')
self.operationCallback(socket, operation);
} catch (err) {
setTimeout(function() {
var docOut = {
str: self.document,
revision: self.operations.length,
clients: self.users,
force: true
};
socket.emit('doc', docOut);
}, 100);
}
});
});
socket.on('get_operations', function (base, head) {
self.onGetOperations(socket, base, head);
});
socket.on('selection', function (obj) {
socket.origin = 'selection';
self.mayWrite(socket, function (mayWrite) {
if (!mayWrite) {
logger.info("User doesn't have the right to edit.");
return;
}
self.updateSelection(socket, obj && Selection.fromJSON(obj));
});
});
socket.on('disconnect', function () {
logger.debug("Disconnect");
socket.leave(self.docId);
self.onDisconnect(socket);
/*
if (socket.manager && socket.manager.sockets.clients(self.docId).length === 0) {
self.emit('empty-room');
}
*/
});
};
EditorSocketIOServer.prototype.onOperation = function (socket, revision, operation, selection) {
var wrapped;
try {
wrapped = new WrappedOperation(
TextOperation.fromJSON(operation),
selection && Selection.fromJSON(selection)
);
} catch (exc) {
logger.error("Invalid operation received: ");
logger.error(exc);
throw new Error(exc);
}
try {
var clientId = socket.id;
var wrappedPrime = this.receiveOperation(revision, wrapped);
if(!wrappedPrime) return;
logger.debug("new operation: " + JSON.stringify(wrapped));
this.getClient(clientId).selection = wrappedPrime.meta;
revision = this.operations.length;
socket.emit('ack', revision);
socket.broadcast.in(this.docId).emit(
'operation', clientId, revision,
wrappedPrime.wrapped.toJSON(), wrappedPrime.meta
);
//set document is dirty
this.isDirty = true;
} catch (exc) {
logger.error(exc);
throw new Error(exc);
}
};
EditorSocketIOServer.prototype.onGetOperations = function (socket, base, head) {
var operations = this.operations.slice(base, head).map(function (op) {
return op.wrapped.toJSON();
});
socket.emit('operations', head, operations);
};
EditorSocketIOServer.prototype.updateSelection = function (socket, selection) {
var clientId = socket.id;
if (selection) {
this.getClient(clientId).selection = selection;
} else {
delete this.getClient(clientId).selection;
}
socket.broadcast.to(this.docId).emit('selection', clientId, selection);
};
EditorSocketIOServer.prototype.setName = function (socket, name) {
var clientId = socket.id;
this.getClient(clientId).name = name;
socket.broadcast.to(this.docId).emit('set_name', clientId, name);
};
EditorSocketIOServer.prototype.setColor = function (socket, color) {
var clientId = socket.id;
this.getClient(clientId).color = color;
socket.broadcast.to(this.docId).emit('set_color', clientId, color);
};
EditorSocketIOServer.prototype.getClient = function (clientId) {
return this.users[clientId] || (this.users[clientId] = {});
};
EditorSocketIOServer.prototype.onDisconnect = function (socket) {
var clientId = socket.id;
delete this.users[clientId];
socket.broadcast.to(this.docId).emit('client_left', clientId);
};
module.exports = EditorSocketIOServer;

8
lib/ot/index.js
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@ -1,8 +0,0 @@
exports.version = '0.0.15';
exports.TextOperation = require('./text-operation');
exports.SimpleTextOperation = require('./simple-text-operation');
exports.Client = require('./client');
exports.Server = require('./server');
exports.Selection = require('./selection');
exports.EditorSocketIOServer = require('./editor-socketio-server');

117
lib/ot/selection.js
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@ -1,117 +0,0 @@
if (typeof ot === 'undefined') {
// Export for browsers
var ot = {};
}
ot.Selection = (function (global) {
'use strict';
var TextOperation = global.ot ? global.ot.TextOperation : require('./text-operation');
// Range has `anchor` and `head` properties, which are zero-based indices into
// the document. The `anchor` is the side of the selection that stays fixed,
// `head` is the side of the selection where the cursor is. When both are
// equal, the range represents a cursor.
function Range (anchor, head) {
this.anchor = anchor;
this.head = head;
}
Range.fromJSON = function (obj) {
return new Range(obj.anchor, obj.head);
};
Range.prototype.equals = function (other) {
return this.anchor === other.anchor && this.head === other.head;
};
Range.prototype.isEmpty = function () {
return this.anchor === this.head;
};
Range.prototype.transform = function (other) {
function transformIndex (index) {
var newIndex = index;
var ops = other.ops;
for (var i = 0, l = other.ops.length; i < l; i++) {
if (TextOperation.isRetain(ops[i])) {
index -= ops[i];
} else if (TextOperation.isInsert(ops[i])) {
newIndex += ops[i].length;
} else {
newIndex -= Math.min(index, -ops[i]);
index += ops[i];
}
if (index < 0) { break; }
}
return newIndex;
}
var newAnchor = transformIndex(this.anchor);
if (this.anchor === this.head) {
return new Range(newAnchor, newAnchor);
}
return new Range(newAnchor, transformIndex(this.head));
};
// A selection is basically an array of ranges. Every range represents a real
// selection or a cursor in the document (when the start position equals the
// end position of the range). The array must not be empty.
function Selection (ranges) {
this.ranges = ranges || [];
}
Selection.Range = Range;
// Convenience method for creating selections only containing a single cursor
// and no real selection range.
Selection.createCursor = function (position) {
return new Selection([new Range(position, position)]);
};
Selection.fromJSON = function (obj) {
var objRanges = obj.ranges || obj;
for (var i = 0, ranges = []; i < objRanges.length; i++) {
ranges[i] = Range.fromJSON(objRanges[i]);
}
return new Selection(ranges);
};
Selection.prototype.equals = function (other) {
if (this.position !== other.position) { return false; }
if (this.ranges.length !== other.ranges.length) { return false; }
// FIXME: Sort ranges before comparing them?
for (var i = 0; i < this.ranges.length; i++) {
if (!this.ranges[i].equals(other.ranges[i])) { return false; }
}
return true;
};
Selection.prototype.somethingSelected = function () {
for (var i = 0; i < this.ranges.length; i++) {
if (!this.ranges[i].isEmpty()) { return true; }
}
return false;
};
// Return the more current selection information.
Selection.prototype.compose = function (other) {
return other;
};
// Update the selection with respect to an operation.
Selection.prototype.transform = function (other) {
for (var i = 0, newRanges = []; i < this.ranges.length; i++) {
newRanges[i] = this.ranges[i].transform(other);
}
return new Selection(newRanges);
};
return Selection;
}(this));
// Export for CommonJS
if (typeof module === 'object') {
module.exports = ot.Selection;
}

52
lib/ot/server.js
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@ -1,52 +0,0 @@
var config = require('../config');
if (typeof ot === 'undefined') {
var ot = {};
}
ot.Server = (function (global) {
'use strict';
// Constructor. Takes the current document as a string and optionally the array
// of all operations.
function Server (document, operations) {
this.document = document;
this.operations = operations || [];
}
// Call this method whenever you receive an operation from a client.
Server.prototype.receiveOperation = function (revision, operation) {
if (revision < 0 || this.operations.length < revision) {
throw new Error("operation revision not in history");
}
// Find all operations that the client didn't know of when it sent the
// operation ...
var concurrentOperations = this.operations.slice(revision);
// ... and transform the operation against all these operations ...
var transform = operation.constructor.transform;
for (var i = 0; i < concurrentOperations.length; i++) {
operation = transform(operation, concurrentOperations[i])[0];
}
// ... and apply that on the document.
var newDocument = operation.apply(this.document);
// ignore if exceed the max length of document
if(newDocument.length > config.documentMaxLength && newDocument.length > this.document.length)
return;
this.document = newDocument;
// Store operation in history.
this.operations.push(operation);
// It's the caller's responsibility to send the operation to all connected
// clients and an acknowledgement to the creator.
return operation;
};
return Server;
}(this));
if (typeof module === 'object') {
module.exports = ot.Server;
}

188
lib/ot/simple-text-operation.js
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@ -1,188 +0,0 @@
if (typeof ot === 'undefined') {
// Export for browsers
var ot = {};
}
ot.SimpleTextOperation = (function (global) {
var TextOperation = global.ot ? global.ot.TextOperation : require('./text-operation');
function SimpleTextOperation () {}
// Insert the string `str` at the zero-based `position` in the document.
function Insert (str, position) {
if (!this || this.constructor !== SimpleTextOperation) {
// => function was called without 'new'
return new Insert(str, position);
}
this.str = str;
this.position = position;
}
Insert.prototype = new SimpleTextOperation();
SimpleTextOperation.Insert = Insert;
Insert.prototype.toString = function () {
return 'Insert(' + JSON.stringify(this.str) + ', ' + this.position + ')';
};
Insert.prototype.equals = function (other) {
return other instanceof Insert &&
this.str === other.str &&
this.position === other.position;
};
Insert.prototype.apply = function (doc) {
return doc.slice(0, this.position) + this.str + doc.slice(this.position);
};
// Delete `count` many characters at the zero-based `position` in the document.
function Delete (count, position) {
if (!this || this.constructor !== SimpleTextOperation) {
return new Delete(count, position);
}
this.count = count;
this.position = position;
}
Delete.prototype = new SimpleTextOperation();
SimpleTextOperation.Delete = Delete;
Delete.prototype.toString = function () {
return 'Delete(' + this.count + ', ' + this.position + ')';
};
Delete.prototype.equals = function (other) {
return other instanceof Delete &&
this.count === other.count &&
this.position === other.position;
};
Delete.prototype.apply = function (doc) {
return doc.slice(0, this.position) + doc.slice(this.position + this.count);
};
// An operation that does nothing. This is needed for the result of the
// transformation of two deletions of the same character.
function Noop () {
if (!this || this.constructor !== SimpleTextOperation) { return new Noop(); }
}
Noop.prototype = new SimpleTextOperation();
SimpleTextOperation.Noop = Noop;
Noop.prototype.toString = function () {
return 'Noop()';
};
Noop.prototype.equals = function (other) { return other instanceof Noop; };
Noop.prototype.apply = function (doc) { return doc; };
var noop = new Noop();
SimpleTextOperation.transform = function (a, b) {
if (a instanceof Noop || b instanceof Noop) { return [a, b]; }
if (a instanceof Insert && b instanceof Insert) {
if (a.position < b.position || (a.position === b.position && a.str < b.str)) {
return [a, new Insert(b.str, b.position + a.str.length)];
}
if (a.position > b.position || (a.position === b.position && a.str > b.str)) {
return [new Insert(a.str, a.position + b.str.length), b];
}
return [noop, noop];
}
if (a instanceof Insert && b instanceof Delete) {
if (a.position <= b.position) {
return [a, new Delete(b.count, b.position + a.str.length)];
}
if (a.position >= b.position + b.count) {
return [new Insert(a.str, a.position - b.count), b];
}
// Here, we have to delete the inserted string of operation a.
// That doesn't preserve the intention of operation a, but it's the only
// thing we can do to get a valid transform function.
return [noop, new Delete(b.count + a.str.length, b.position)];
}
if (a instanceof Delete && b instanceof Insert) {
if (a.position >= b.position) {
return [new Delete(a.count, a.position + b.str.length), b];
}
if (a.position + a.count <= b.position) {
return [a, new Insert(b.str, b.position - a.count)];
}
// Same problem as above. We have to delete the string that was inserted
// in operation b.
return [new Delete(a.count + b.str.length, a.position), noop];
}
if (a instanceof Delete && b instanceof Delete) {
if (a.position === b.position) {
if (a.count === b.count) {
return [noop, noop];
} else if (a.count < b.count) {
return [noop, new Delete(b.count - a.count, b.position)];
}
return [new Delete(a.count - b.count, a.position), noop];
}
if (a.position < b.position) {
if (a.position + a.count <= b.position) {
return [a, new Delete(b.count, b.position - a.count)];
}
if (a.position + a.count >= b.position + b.count) {
return [new Delete(a.count - b.count, a.position), noop];
}
return [
new Delete(b.position - a.position, a.position),
new Delete(b.position + b.count - (a.position + a.count), a.position)
];
}
if (a.position > b.position) {
if (a.position >= b.position + b.count) {
return [new Delete(a.count, a.position - b.count), b];
}
if (a.position + a.count <= b.position + b.count) {
return [noop, new Delete(b.count - a.count, b.position)];
}
return [
new Delete(a.position + a.count - (b.position + b.count), b.position),
new Delete(a.position - b.position, b.position)
];
}
}
};
// Convert a normal, composable `TextOperation` into an array of
// `SimpleTextOperation`s.
SimpleTextOperation.fromTextOperation = function (operation) {
var simpleOperations = [];
var index = 0;
for (var i = 0; i < operation.ops.length; i++) {
var op = operation.ops[i];
if (TextOperation.isRetain(op)) {
index += op;
} else if (TextOperation.isInsert(op)) {
simpleOperations.push(new Insert(op, index));
index += op.length;
} else {
simpleOperations.push(new Delete(Math.abs(op), index));
}
}
return simpleOperations;
};
return SimpleTextOperation;
})(this);
// Export for CommonJS
if (typeof module === 'object') {
module.exports = ot.SimpleTextOperation;
}

530
lib/ot/text-operation.js
View File

@ -1,530 +0,0 @@
if (typeof ot === 'undefined') {
// Export for browsers
var ot = {};
}
ot.TextOperation = (function () {
'use strict';
// Constructor for new operations.
function TextOperation () {
if (!this || this.constructor !== TextOperation) {
// => function was called without 'new'
return new TextOperation();
}
// When an operation is applied to an input string, you can think of this as
// if an imaginary cursor runs over the entire string and skips over some
// parts, deletes some parts and inserts characters at some positions. These
// actions (skip/delete/insert) are stored as an array in the "ops" property.
this.ops = [];
// An operation's baseLength is the length of every string the operation
// can be applied to.
this.baseLength = 0;
// The targetLength is the length of every string that results from applying
// the operation on a valid input string.
this.targetLength = 0;
}
TextOperation.prototype.equals = function (other) {
if (this.baseLength !== other.baseLength) { return false; }
if (this.targetLength !== other.targetLength) { return false; }
if (this.ops.length !== other.ops.length) { return false; }
for (var i = 0; i < this.ops.length; i++) {
if (this.ops[i] !== other.ops[i]) { return false; }
}
return true;
};
// Operation are essentially lists of ops. There are three types of ops:
//
// * Retain ops: Advance the cursor position by a given number of characters.
// Represented by positive ints.
// * Insert ops: Insert a given string at the current cursor position.
// Represented by strings.
// * Delete ops: Delete the next n characters. Represented by negative ints.
var isRetain = TextOperation.isRetain = function (op) {
return typeof op === 'number' && op > 0;
};
var isInsert = TextOperation.isInsert = function (op) {
return typeof op === 'string';
};
var isDelete = TextOperation.isDelete = function (op) {
return typeof op === 'number' && op < 0;
};
// After an operation is constructed, the user of the library can specify the
// actions of an operation (skip/insert/delete) with these three builder
// methods. They all return the operation for convenient chaining.
// Skip over a given number of characters.
TextOperation.prototype.retain = function (n) {
if (typeof n !== 'number') {
throw new Error("retain expects an integer");
}
if (n === 0) { return this; }
this.baseLength += n;
this.targetLength += n;
if (isRetain(this.ops[this.ops.length-1])) {
// The last op is a retain op => we can merge them into one op.
this.ops[this.ops.length-1] += n;
} else {
// Create a new op.
this.ops.push(n);
}
return this;
};
// Insert a string at the current position.
TextOperation.prototype.insert = function (str) {
if (typeof str !== 'string') {
throw new Error("insert expects a string");
}
if (str === '') { return this; }
this.targetLength += str.length;
var ops = this.ops;
if (isInsert(ops[ops.length-1])) {
// Merge insert op.
ops[ops.length-1] += str;
} else if (isDelete(ops[ops.length-1])) {
// It doesn't matter when an operation is applied whether the operation
// is delete(3), insert("something") or insert("something"), delete(3).
// Here we enforce that in this case, the insert op always comes first.
// This makes all operations that have the same effect when applied to
// a document of the right length equal in respect to the `equals` method.
if (isInsert(ops[ops.length-2])) {
ops[ops.length-2] += str;
} else {
ops[ops.length] = ops[ops.length-1];
ops[ops.length-2] = str;
}
} else {
ops.push(str);
}
return this;
};
// Delete a string at the current position.
TextOperation.prototype['delete'] = function (n) {
if (typeof n === 'string') { n = n.length; }
if (typeof n !== 'number') {
throw new Error("delete expects an integer or a string");
}
if (n === 0) { return this; }
if (n > 0) { n = -n; }
this.baseLength -= n;
if (isDelete(this.ops[this.ops.length-1])) {
this.ops[this.ops.length-1] += n;
} else {
this.ops.push(n);
}
return this;
};
// Tests whether this operation has no effect.
TextOperation.prototype.isNoop = function () {
return this.ops.length === 0 || (this.ops.length === 1 && isRetain(this.ops[0]));
};
// Pretty printing.
TextOperation.prototype.toString = function () {
// map: build a new array by applying a function to every element in an old
// array.
var map = Array.prototype.map || function (fn) {
var arr = this;
var newArr = [];
for (var i = 0, l = arr.length; i < l; i++) {
newArr[i] = fn(arr[i]);
}
return newArr;
};
return map.call(this.ops, function (op) {
if (isRetain(op)) {
return "retain " + op;
} else if (isInsert(op)) {
return "insert '" + op + "'";
} else {
return "delete " + (-op);
}
}).join(', ');
};
// Converts operation into a JSON value.
TextOperation.prototype.toJSON = function () {
return this.ops;
};
// Converts a plain JS object into an operation and validates it.
TextOperation.fromJSON = function (ops) {
var o = new TextOperation();
for (var i = 0, l = ops.length; i < l; i++) {
var op = ops[i];
if (isRetain(op)) {
o.retain(op);
} else if (isInsert(op)) {
o.insert(op);
} else if (isDelete(op)) {
o['delete'](op);
} else {
throw new Error("unknown operation: " + JSON.stringify(op));
}
}
return o;
};
// Apply an operation to a string, returning a new string. Throws an error if
// there's a mismatch between the input string and the operation.
TextOperation.prototype.apply = function (str) {
var operation = this;
if (str.length !== operation.baseLength) {
throw new Error("The operation's base length must be equal to the string's length.");
}
var newStr = [], j = 0;
var strIndex = 0;
var ops = this.ops;
for (var i = 0, l = ops.length; i < l; i++) {
var op = ops[i];
if (isRetain(op)) {
if (strIndex + op > str.length) {
throw new Error("Operation can't retain more characters than are left in the string.");
}
// Copy skipped part of the old string.
newStr[j++] = str.slice(strIndex, strIndex + op);
strIndex += op;
} else if (isInsert(op)) {
// Insert string.
newStr[j++] = op;
} else { // delete op
strIndex -= op;
}
}
if (strIndex !== str.length) {
throw new Error("The operation didn't operate on the whole string.");
}
return newStr.join('');
};
// Computes the inverse of an operation. The inverse of an operation is the
// operation that reverts the effects of the operation, e.g. when you have an
// operation 'insert("hello "); skip(6);' then the inverse is 'delete("hello ");
// skip(6);'. The inverse should be used for implementing undo.
TextOperation.prototype.invert = function (str) {
var strIndex = 0;
var inverse = new TextOperation();
var ops = this.ops;
for (var i = 0, l = ops.length; i < l; i++) {
var op = ops[i];
if (isRetain(op)) {
inverse.retain(op);
strIndex += op;
} else if (isInsert(op)) {
inverse['delete'](op.length);
} else { // delete op
inverse.insert(str.slice(strIndex, strIndex - op));
strIndex -= op;
}
}
return inverse;
};
// Compose merges two consecutive operations into one operation, that
// preserves the changes of both. Or, in other words, for each input string S
// and a pair of consecutive operations A and B,
// apply(apply(S, A), B) = apply(S, compose(A, B)) must hold.
TextOperation.prototype.compose = function (operation2) {
var operation1 = this;
if (operation1.targetLength !== operation2.baseLength) {
throw new Error("The base length of the second operation has to be the target length of the first operation");
}
var operation = new TextOperation(); // the combined operation
var ops1 = operation1.ops, ops2 = operation2.ops; // for fast access
var i1 = 0, i2 = 0; // current index into ops1 respectively ops2
var op1 = ops1[i1++], op2 = ops2[i2++]; // current ops
while (true) {
// Dispatch on the type of op1 and op2
if (typeof op1 === 'undefined' && typeof op2 === 'undefined') {
// end condition: both ops1 and ops2 have been processed
break;
}
if (isDelete(op1)) {
operation['delete'](op1);
op1 = ops1[i1++];
continue;
}
if (isInsert(op2)) {
operation.insert(op2);
op2 = ops2[i2++];
continue;
}
if (typeof op1 === 'undefined') {
throw new Error("Cannot compose operations: first operation is too short.");
}
if (typeof op2 === 'undefined') {
throw new Error("Cannot compose operations: first operation is too long.");
}
if (isRetain(op1) && isRetain(op2)) {
if (op1 > op2) {
operation.retain(op2);
op1 = op1 - op2;
op2 = ops2[i2++];
} else if (op1 === op2) {
operation.retain(op1);
op1 = ops1[i1++];
op2 = ops2[i2++];
} else {
operation.retain(op1);
op2 = op2 - op1;
op1 = ops1[i1++];
}
} else if (isInsert(op1) && isDelete(op2)) {
if (op1.length > -op2) {
op1 = op1.slice(-op2);
op2 = ops2[i2++];
} else if (op1.length === -op2) {
op1 = ops1[i1++];
op2 = ops2[i2++];
} else {
op2 = op2 + op1.length;
op1 = ops1[i1++];
}
} else if (isInsert(op1) && isRetain(op2)) {
if (op1.length > op2) {
operation.insert(op1.slice(0, op2));
op1 = op1.slice(op2);
op2 = ops2[i2++];
} else if (op1.length === op2) {
operation.insert(op1);
op1 = ops1[i1++];
op2 = ops2[i2++];
} else {
operation.insert(op1);
op2 = op2 - op1.length;
op1 = ops1[i1++];
}
} else if (isRetain(op1) && isDelete(op2)) {
if (op1 > -op2) {
operation['delete'](op2);
op1 = op1 + op2;
op2 = ops2[i2++];
} else if (op1 === -op2) {
operation['delete'](op2);
op1 = ops1[i1++];
op2 = ops2[i2++];
} else {
operation['delete'](op1);
op2 = op2 + op1;
op1 = ops1[i1++];
}
} else {
throw new Error(
"This shouldn't happen: op1: " +
JSON.stringify(op1) + ", op2: " +
JSON.stringify(op2)
);
}
}
return operation;
};
function getSimpleOp (operation, fn) {
var ops = operation.ops;
var isRetain = TextOperation.isRetain;
switch (ops.length) {
case 1:
return ops[0];
case 2:
return isRetain(ops[0]) ? ops[1] : (isRetain(ops[1]) ? ops[0] : null);
case 3:
if (isRetain(ops[0]) && isRetain(ops[2])) { return ops[1]; }
}
return null;
}
function getStartIndex (operation) {
if (isRetain(operation.ops[0])) { return operation.ops[0]; }
return 0;
}
// When you use ctrl-z to undo your latest changes, you expect the program not
// to undo every single keystroke but to undo your last sentence you wrote at
// a stretch or the deletion you did by holding the backspace key down. This
// This can be implemented by composing operations on the undo stack. This
// method can help decide whether two operations should be composed. It
// returns true if the operations are consecutive insert operations or both
// operations delete text at the same position. You may want to include other
// factors like the time since the last change in your decision.
TextOperation.prototype.shouldBeComposedWith = function (other) {
if (this.isNoop() || other.isNoop()) { return true; }
var startA = getStartIndex(this), startB = getStartIndex(other);
var simpleA = getSimpleOp(this), simpleB = getSimpleOp(other);
if (!simpleA || !simpleB) { return false; }
if (isInsert(simpleA) && isInsert(simpleB)) {
return startA + simpleA.length === startB;
}
if (isDelete(simpleA) && isDelete(simpleB)) {
// there are two possibilities to delete: with backspace and with the
// delete key.
return (startB - simpleB === startA) || startA === startB;
}
return false;
};
// Decides whether two operations should be composed with each other
// if they were inverted, that is
// `shouldBeComposedWith(a, b) = shouldBeComposedWithInverted(b^{-1}, a^{-1})`.
TextOperation.prototype.shouldBeComposedWithInverted = function (other) {
if (this.isNoop() || other.isNoop()) { return true; }
var startA = getStartIndex(this), startB = getStartIndex(other);
var simpleA = getSimpleOp(this), simpleB = getSimpleOp(other);
if (!simpleA || !simpleB) { return false; }
if (isInsert(simpleA) && isInsert(simpleB)) {
return startA + simpleA.length === startB || startA === startB;
}
if (isDelete(simpleA) && isDelete(simpleB)) {
return startB - simpleB === startA;
}
return false;
};
// Transform takes two operations A and B that happened concurrently and
// produces two operations A' and B' (in an array) such that
// `apply(apply(S, A), B') = apply(apply(S, B), A')`. This function is the
// heart of OT.
TextOperation.transform = function (operation1, operation2) {
if (operation1.baseLength !== operation2.baseLength) {
throw new Error("Both operations have to have the same base length");
}
var operation1prime = new TextOperation();
var operation2prime = new TextOperation();
var ops1 = operation1.ops, ops2 = operation2.ops;
var i1 = 0, i2 = 0;
var op1 = ops1[i1++], op2 = ops2[i2++];
while (true) {
// At every iteration of the loop, the imaginary cursor that both
// operation1 and operation2 have that operates on the input string must
// have the same position in the input string.
if (typeof op1 === 'undefined' && typeof op2 === 'undefined') {
// end condition: both ops1 and ops2 have been processed
break;
}
// next two cases: one or both ops are insert ops
// => insert the string in the corresponding prime operation, skip it in
// the other one. If both op1 and op2 are insert ops, prefer op1.
if (isInsert(op1)) {
operation1prime.insert(op1);
operation2prime.retain(op1.length);
op1 = ops1[i1++];
continue;
}
if (isInsert(op2)) {
operation1prime.retain(op2.length);
operation2prime.insert(op2);
op2 = ops2[i2++];
continue;
}
if (typeof op1 === 'undefined') {
throw new Error("Cannot compose operations: first operation is too short.");
}
if (typeof op2 === 'undefined') {
throw new Error("Cannot compose operations: first operation is too long.");
}
var minl;
if (isRetain(op1) && isRetain(op2)) {
// Simple case: retain/retain
if (op1 > op2) {
minl = op2;
op1 = op1 - op2;
op2 = ops2[i2++];
} else if (op1 === op2) {
minl = op2;
op1 = ops1[i1++];
op2 = ops2[i2++];
} else {
minl = op1;
op2 = op2 - op1;
op1 = ops1[i1++];
}
operation1prime.retain(minl);
operation2prime.retain(minl);
} else if (isDelete(op1) && isDelete(op2)) {
// Both operations delete the same string at the same position. We don't
// need to produce any operations, we just skip over the delete ops and
// handle the case that one operation deletes more than the other.
if (-op1 > -op2) {
op1 = op1 - op2;
op2 = ops2[i2++];
} else if (op1 === op2) {
op1 = ops1[i1++];
op2 = ops2[i2++];
} else {
op2 = op2 - op1;
op1 = ops1[i1++];
}
// next two cases: delete/retain and retain/delete
} else if (isDelete(op1) && isRetain(op2)) {
if (-op1 > op2) {
minl = op2;
op1 = op1 + op2;
op2 = ops2[i2++];
} else if (-op1 === op2) {
minl = op2;
op1 = ops1[i1++];
op2 = ops2[i2++];
} else {
minl = -op1;
op2 = op2 + op1;
op1 = ops1[i1++];
}
operation1prime['delete'](minl);
} else if (isRetain(op1) && isDelete(op2)) {
if (op1 > -op2) {
minl = -op2;
op1 = op1 + op2;
op2 = ops2[i2++];
} else if (op1 === -op2) {
minl = op1;
op1 = ops1[i1++];
op2 = ops2[i2++];
} else {
minl = op1;
op2 = op2 + op1;
op1 = ops1[i1++];
}
operation2prime['delete'](minl);
} else {
throw new Error("The two operations aren't compatible");
}
}
return [operation1prime, operation2prime];
};
return TextOperation;
}());
// Export for CommonJS
if (typeof module === 'object') {
module.exports = ot.TextOperation;
}

80
lib/ot/wrapped-operation.js
View File

@ -1,80 +0,0 @@
if (typeof ot === 'undefined') {
// Export for browsers
var ot = {};
}
ot.WrappedOperation = (function (global) {
'use strict';
// A WrappedOperation contains an operation and corresponing metadata.
function WrappedOperation (operation, meta) {
this.wrapped = operation;
this.meta = meta;
}
WrappedOperation.prototype.apply = function () {
return this.wrapped.apply.apply(this.wrapped, arguments);
};
WrappedOperation.prototype.invert = function () {
var meta = this.meta;
return new WrappedOperation(
this.wrapped.invert.apply(this.wrapped, arguments),
meta && typeof meta === 'object' && typeof meta.invert === 'function' ?
meta.invert.apply(meta, arguments) : meta
);
};
// Copy all properties from source to target.
function copy (source, target) {
for (var key in source) {
if (source.hasOwnProperty(key)) {
target[key] = source[key];
}
}
}
function composeMeta (a, b) {
if (a && typeof a === 'object') {
if (typeof a.compose === 'function') { return a.compose(b); }
var meta = {};
copy(a, meta);
copy(b, meta);
return meta;
}
return b;
}
WrappedOperation.prototype.compose = function (other) {
return new WrappedOperation(
this.wrapped.compose(other.wrapped),
composeMeta(this.meta, other.meta)
);
};
function transformMeta (meta, operation) {
if (meta && typeof meta === 'object') {
if (typeof meta.transform === 'function') {
return meta.transform(operation);
}
}
return meta;
}
WrappedOperation.transform = function (a, b) {
var transform = a.wrapped.constructor.transform;
var pair = transform(a.wrapped, b.wrapped);
return [
new WrappedOperation(pair[0], transformMeta(a.meta, b.wrapped)),
new WrappedOperation(pair[1], transformMeta(b.meta, a.wrapped))
];
};
return WrappedOperation;
}(this));
// Export for CommonJS
if (typeof module === 'object') {
module.exports = ot.WrappedOperation;
}

2
lib/realtime/realtime.ts
View File

@ -15,7 +15,7 @@ import * as history from "../history";
import * as models from "../models";
// ot
import * as ot from "../ot";
import * as ot from "ot";
import {ProcessQueue} from "./processQueue";
import {RealtimeClientConnection} from "./realtimeClientConnection";

4
package-lock.json generated
View File

@ -11739,6 +11739,10 @@
"os-tmpdir": "^1.0.0"
}
},
"ot": {
"version": "git+https://github.com/hackmdio/ot.js.git#cc1f3383e70b58ffe7f0da3c3b10ece0f606dc09",
"from": "git+https://github.com/hackmdio/ot.js.git#cc1f338"
},
"p-cancelable": {
"version": "1.1.0",
"resolved": "https://registry.npmjs.org/p-cancelable/-/p-cancelable-1.1.0.tgz",

1
package.json
View File

@ -72,6 +72,7 @@
"morgan": "~1.9.1",
"mysql": "~2.17.1",
"mysql2": "^2.0.1",
"ot": "git+https://github.com/hackmdio/ot.js.git#cc1f338",
"passport": "~0.4.0",
"passport-bitbucket-oauth2": "~0.1.2",
"passport-dropbox-oauth2": "~1.1.0",