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Rework file transfer.

Split into the protocol (in protocol.js) and the user interface
(in galene.js).  Make the state automaton explicit, and improve
error-handling.  The new protocol is incompatible with the old one.
This commit is contained in:
Juliusz Chroboczek 2022-07-23 20:52:04 +02:00
parent 7d4133d1c3
commit 3bdd82f06d
2 changed files with 647 additions and 494 deletions

View file

@ -2328,96 +2328,11 @@ async function gotJoined(kind, group, perms, status, data, message) {
}
}
/** @type {Object<string,TransferredFile>} */
let transferredFiles = {};
/**
* A file in the process of being transferred.
*
* @constructor
*/
function TransferredFile(id, userid, up, username, name, type, size) {
/** @type {string} */
this.id = id;
/** @type {string} */
this.userid = userid;
/** @type {boolean} */
this.up = up;
/** @type {string} */
this.username = username;
/** @type {string} */
this.name = name;
/** @type {string} */
this.type = type;
/** @type {number} */
this.size = size;
/** @type {File} */
this.file = null;
/** @type {RTCPeerConnection} */
this.pc = null;
/** @type {RTCDataChannel} */
this.dc = null;
/** @type {Array<RTCIceCandidateInit>} */
this.candidates = [];
/** @type {Array<Blob|ArrayBuffer>} */
this.data = [];
/** @type {number} */
this.datalen = 0;
}
TransferredFile.prototype.fullid = function() {
return this.userid + (this.up ? '+' : '-') + this.id;
};
/**
* @param {boolean} up
* @param {string} userid
* @param {string} fileid
* @returns {TransferredFile}
*/
TransferredFile.get = function(up, userid, fileid) {
return transferredFiles[userid + (up ? '+' : '-') + fileid];
};
TransferredFile.prototype.close = function() {
if(this.dc) {
this.dc.onclose = null;
this.dc.onerror = null;
this.dc.onmessage = null;
}
if(this.pc)
this.pc.close();
this.dc = null;
this.pc = null;
this.data = [];
this.datalen = 0;
delete(transferredFiles[this.fullid()]);
}
TransferredFile.prototype.pushData = function(data) {
if(data instanceof Blob) {
this.datalen += data.size;
} else if(data instanceof ArrayBuffer) {
this.datalen += data.byteLength;
} else {
throw new Error('unexpected type for received data');
}
this.data.push(data);
}
TransferredFile.prototype.getData = function() {
let blob = new Blob(this.data, {type: this.type});
if(blob.size != this.datalen)
throw new Error('Inconsistent data size');
this.data = [];
this.datalen = 0;
return blob;
}
/**
* @param {TransferredFile} f
*/
function fileTransferBox(f) {
function gotFileTransfer(f) {
f.onevent = gotFileTransferEvent;
let p = document.createElement('p');
if(f.up)
p.textContent =
@ -2428,27 +2343,20 @@ function fileTransferBox(f) {
`User ${f.username} offered to send us a file ` +
`called "${f.name}" of size ${f.size}.`
let bno = null, byes = null;
if(f.up) {
bno = document.createElement('button');
bno.textContent = 'Cancel';
bno.onclick = function(e) {
cancelFile(f);
};
bno.id = "bno-" + f.fullid();
} else {
if(!f.up) {
byes = document.createElement('button');
byes.textContent = 'Accept';
byes.onclick = function(e) {
getFile(f);
f.receive();
};
byes.id = "byes-" + f.fullid();
bno = document.createElement('button');
bno.textContent = 'Decline';
bno.onclick = function(e) {
rejectFile(f);
};
bno.id = "bno-" + f.fullid();
}
bno = document.createElement('button');
bno.textContent = f.up ? 'Cancel' : 'Reject';
bno.onclick = function(e) {
f.cancel();
};
bno.id = "bno-" + f.fullid();
let status = document.createElement('div');
status.id = 'status-' + f.fullid();
if(!f.up) {
@ -2500,334 +2408,49 @@ function setFileStatus(f, status, delyes, delno) {
}
/**
* @param {TransferredFile} f
* @param {any} message
* @this {TransferredFile}
* @param {string} state
* @param {any} [data]
*/
function failFile(f, message) {
if(!f.dc)
return;
console.error('File transfer failed:', message);
setFileStatus(f, message ? `Failed: ${message}` : 'Failed.');
f.close();
}
/**
* @param {string} id
* @param {File} file
*/
function offerFile(id, file) {
let fileid = newRandomId();
let username = serverConnection.users[id].username;
let f = new TransferredFile(
fileid, id, true, username, file.name, file.type, file.size,
);
f.file = file;
transferredFiles[f.fullid()] = f;
try {
fileTransferBox(f);
serverConnection.userMessage('offerfile', id, {
id: fileid,
name: f.name,
size: f.size,
type: f.type,
});
} catch(e) {
displayError(e);
f.close();
}
}
/**
* @param {TransferredFile} f
*/
function cancelFile(f) {
serverConnection.userMessage('cancelfile', f.userid, {
id: f.id,
});
f.close();
setFileStatus(f, 'Cancelled.', true, true);
}
/**
* @param {TransferredFile} f
*/
async function getFile(f) {
if(f.pc)
throw new Error("Download already in progress");
setFileStatus(f, 'Connecting...', true);
let pc = new RTCPeerConnection(serverConnection.getRTCConfiguration());
if(!pc)
throw new Error("Couldn't create peer connection");
f.pc = pc;
f.candidates = [];
pc.onsignalingstatechange = function(e) {
if(pc.signalingState === 'stable') {
f.candidates.forEach(c => pc.addIceCandidate(c).catch(console.warn));
f.candidates = [];
}
};
pc.onicecandidate = function(e) {
serverConnection.userMessage('filedownice', f.userid, {
id: f.id,
candidate: e.candidate,
});
};
f.dc = pc.createDataChannel('file');
f.data = [];
f.datalen = 0;
f.dc.onclose = function(e) {
try {
closeReceiveFileData(f);
} catch(e) {
failFile(f, e);
}
};
f.dc.onmessage = function(e) {
try {
receiveFileData(f, e.data);
} catch(e) {
failFile(f, e);
}
};
f.dc.onerror = function(e) {
/** @ts-ignore */
let err = e.error;
failFile(f, err);
};
let offer = await pc.createOffer();
if(!offer)
throw new Error("Couldn't create offer");
await pc.setLocalDescription(offer);
serverConnection.userMessage('getfile', f.userid, {
id: f.id,
offer: pc.localDescription.sdp,
});
setFileStatus(f, 'Negotiating...', true);
}
/**
* @param {TransferredFile} f
*/
async function rejectFile(f) {
serverConnection.userMessage('rejectfile', f.userid, {
id: f.id,
});
setFileStatus(f, 'Rejected.', true, true);
f.close();
}
/**
* @param {TransferredFile} f
* @param {string} sdp
*/
async function sendOfferedFile(f, sdp) {
if(f.pc)
throw new Error('Transfer already in progress');
setFileStatus(f, 'Negotiating...', true);
let pc = new RTCPeerConnection(serverConnection.getRTCConfiguration());
if(!pc)
throw new Error("Couldn't create peer connection");
f.pc = pc;
f.candidates = [];
pc.onicecandidate = function(e) {
serverConnection.userMessage('fileupice', f.userid, {
id: f.id,
candidate: e.candidate,
});
};
pc.onsignalingstatechange = function(e) {
if(pc.signalingState === 'stable') {
f.candidates.forEach(c => pc.addIceCandidate(c).catch(console.warn));
f.candidates = [];
}
};
pc.ondatachannel = function(e) {
if(f.dc)
throw new Error('Duplicate datachannel');
f.dc = /** @type{RTCDataChannel} */(e.channel);
f.dc.onclose = function(e) {
try {
closeSendFileData(f);
} catch(e) {
failFile(f, e);
}
};
f.dc.onerror = function(e) {
/** @ts-ignore */
let err = e.error;
failFile(f, err);
}
f.dc.onmessage = function(e) {
try {
ackSendFileData(f, e.data);
} catch(e) {
failFile(f, e);
}
};
sendFileData(f).catch(e => failFile(f, e));
};
await pc.setRemoteDescription({
type: 'offer',
sdp: sdp,
});
let answer = await pc.createAnswer();
if(!answer)
throw new Error("Couldn't create answer");
await pc.setLocalDescription(answer);
serverConnection.userMessage('sendfile', f.userid, {
id: f.id,
answer: pc.localDescription.sdp,
});
setFileStatus(f, 'Uploading...', true);
}
/**
* @param {TransferredFile} f
* @param {string} sdp
*/
async function receiveFile(f, sdp) {
await f.pc.setRemoteDescription({
type: 'answer',
sdp: sdp,
});
setFileStatus(f, 'Downloading...', true);
}
/**
* @param {TransferredFile} f
*/
async function sendFileData(f) {
let r = f.file.stream().getReader();
f.dc.bufferedAmountLowThreshold = 65536;
async function write(a) {
while(f.dc.bufferedAmount > f.dc.bufferedAmountLowThreshold) {
await new Promise((resolve, reject) => {
if(!f.dc) {
reject(new Error('File is closed.'));
return;
}
f.dc.onbufferedamountlow = function(e) {
if(!f.dc) {
reject(new Error('File is closed.'));
return;
}
f.dc.onbufferedamountlow = null;
resolve();
}
});
}
f.dc.send(a);
f.datalen += a.length;
setFileStatus(f, `Uploading... ${f.datalen}/${f.size}`, true);
}
while(true) {
let v = await r.read();
if(v.done)
break;
if(!(v.value instanceof Uint8Array))
throw new Error('Unexpected type for chunk');
if(v.value.length <= 16384) {
await write(v.value);
} else {
for(let i = 0; i < v.value.length; i += 16384) {
let a = new Uint8Array(
v.value.buffer, i, Math.min(16384, v.value.length - i),
);
await write(a);
}
}
}
}
/**
* @param {TransferredFile} f
*/
function ackSendFileData(f, data) {
if(data === 'done' && f.datalen == f.size)
function gotFileTransferEvent(state, data) {
let f = this;
switch(state) {
case 'inviting':
break;
case 'connecting':
setFileStatus(f, 'Connecting...', true);
break;
case 'connected':
if(f.up)
setFileStatus(f, `Sending... ${f.datalen}/${f.size}`);
else
setFileStatus(f, `Receiving... ${f.datalen}/${f.size}`);
break;
case 'done':
setFileStatus(f, 'Done.', true, true);
else
setFileStatus(f, 'Failed.', true, true);
f.dc.onclose = null;
f.dc.onerror = null;
f.close();
}
/**
* @param {TransferredFile} f
*/
function closeSendFileData(f) {
setFileStatus(f, 'Failed.', true, true);
f.close();
}
/**
* @param {TransferredFile} f
* @param {Blob|ArrayBuffer} data
*/
function receiveFileData(f, data) {
f.pushData(data);
setFileStatus(f, `Downloading... ${f.datalen}/${f.size}`, true);
if(f.datalen < f.size)
return;
if(f.datalen != f.size) {
setFileStatus(f, 'Failed.', true, true);
f.close();
return;
}
f.dc.onmessage = null;
doneReceiveFileData(f);
}
/**
* @param {TransferredFile} f
*/
async function doneReceiveFileData(f) {
setFileStatus(f, 'Done.', true, true);
let blob = f.getData();
await new Promise((resolve, reject) => {
let timer = setTimeout(function(e) { resolve(); }, 2000);
f.dc.onclose = function(e) {
clearTimeout(timer);
resolve();
};
f.dc.onerror = function(e) {
clearTimeout(timer);
resolve();
};
f.dc.send('done');
});
f.dc.onclose = null;
f.dc.onerror = null;
f.close();
let url = URL.createObjectURL(blob);
let a = document.createElement('a');
a.href = url;
a.textContent = f.name;
a.download = f.name;
a.type = f.type;
a.click();
URL.revokeObjectURL(url);
}
/**
* @param {TransferredFile} f
*/
function closeReceiveFileData(f) {
if(f.datalen !== f.size) {
setFileStatus(f, 'Failed.', true, true)
f.close();
if(!f.up) {
let url = URL.createObjectURL(data);
let a = document.createElement('a');
a.href = url;
a.textContent = f.name;
a.download = f.name;
a.type = f.mimetype;
a.click();
URL.revokeObjectURL(url);
}
break;
case 'cancelled':
if(data)
setFileStatus(f, `Cancelled: ${data.toString()}.`, true, true);
else
setFileStatus(f, 'Cancelled.', true, true);
break;
case 'closed':
break;
default:
console.error(`Unexpected state "${state}"`);
f.cancel(`unexpected state "${state}" (this shouldn't happen)`);
break;
}
}
@ -2868,70 +2491,6 @@ function gotUserMessage(id, dest, username, time, privileged, kind, message) {
console.error(`Got unprivileged message of kind ${kind}`);
}
break;
case 'offerfile': {
let f = new TransferredFile(
message.id, id, false, username,
message.name, message.type, message.size,
);
transferredFiles[f.fullid()] = f;
fileTransferBox(f);
break;
}
case 'cancelfile': {
let f = TransferredFile.get(false, id, message.id);
if(!f)
throw new Error('unexpected cancelfile');
setFileStatus(f, 'Cancelled.', true, true);
f.close();
break;
}
case 'getfile': {
let f = TransferredFile.get(true, id, message.id);
if(!f)
throw new Error('unexpected getfile');
sendOfferedFile(f, message.offer);
break;
}
case 'rejectfile': {
let f = TransferredFile.get(true, id, message.id);
if(!f)
throw new Error('unexpected rejectfile');
setFileStatus(f, 'Rejected.', true, true);
f.close();
break;
}
case 'sendfile': {
let f = TransferredFile.get(false, id, message.id);
if(!f)
throw new Error('unexpected sendfile');
receiveFile(f, message.answer);
break;
}
case 'filedownice': {
let f = TransferredFile.get(true, id, message.id);
if(!f.pc) {
console.warn('Unexpected filedownice');
return;
}
if(f.pc.signalingState === 'stable')
f.pc.addIceCandidate(message.candidate).catch(console.warn);
else
f.candidates.push(message.candidate);
break;
}
case 'fileupice': {
let f = TransferredFile.get(false, id, message.id);
if(!f.pc) {
console.warn('Unexpected fileupice');
return;
}
if(f.pc.signalingState === 'stable')
f.pc.addIceCandidate(message.candidate).catch(console.warn);
else
f.candidates.push(message.candidate);
break;
}
default:
console.warn(`Got unknown user message ${kind}`);
break;
@ -3515,7 +3074,7 @@ function sendFile(id) {
let files = this.files;
for(let i = 0; i < files.length; i++) {
try {
offerFile(id, files[i]);
serverConnection.sendFile(id, files[i]);
} catch(e) {
console.error(e);
displayError(e);
@ -3870,6 +3429,7 @@ async function serverConnect() {
serverConnection.onjoined = gotJoined;
serverConnection.onchat = addToChatbox;
serverConnection.onusermessage = gotUserMessage;
serverConnection.onfiletransfer = gotFileTransfer;
let url = `ws${location.protocol === 'https:' ? 's' : ''}://${location.host}/ws`;
try {

View file

@ -202,6 +202,14 @@ function ServerConnection() {
* @type {(this: ServerConnection, id: string, dest: string, username: string, time: number, privileged: boolean, kind: string, message: unknown) => void}
*/
this.onusermessage = null;
/**
* @type {Object<string,TransferredFile>}
*/
this.transferredFiles = {};
/**
* @type {(this: ServerConnection, f: TransferredFile) => void}
*/
this.onfiletransfer = null;
}
/**
@ -380,6 +388,11 @@ ServerConnection.prototype.connect = async function(url) {
case 'delete':
if(!(m.id in sc.users))
console.warn(`Unknown user ${m.id} ${m.username}`);
for(let t in sc.transferredFiles) {
let f = sc.transferredFiles[t];
if(f.userid === m.id)
f.fail('user has gone away');
}
delete(sc.users[m.id]);
break;
default:
@ -398,7 +411,9 @@ ServerConnection.prototype.connect = async function(url) {
);
break;
case 'usermessage':
if(sc.onusermessage)
if(m.kind === 'filetransfer')
sc.fileTransfer(m.source, m.username, m.value);
else if(sc.onusermessage)
sc.onusermessage.call(
sc, m.source, m.dest, m.username, m.time,
m.privileged, m.kind, m.value,
@ -1419,3 +1434,581 @@ Stream.prototype.setStatsInterval = function(ms) {
c.updateStats();
}, ms);
};
/**
* A file in the process of being transferred.
* These are stored in the ServerConnection.transferredFiles dictionary.
*
* @parm {ServerConnection} sc
* @parm {string} userid
* @parm {string} rid
* @parm {boolean} up
* @parm {string} username
* @parm {string} mimetype
* @parm {number} size
* @constructor
*
* State transitions:
*
* '' -> inviting -> connecting -> connected -> done -> closed
* any -> cancelled -> closed
*
*/
function TransferredFile(sc, userid, id, up, username, name, mimetype, size) {
/** @type {ServerConnection} */
this.sc = sc;
/** @type {string} */
this.userid = userid;
/** @type {string} */
this.id = id;
/** @type {boolean} */
this.up = up;
/** @type {string} */
this.state = '';
/** @type {string} */
this.username = username;
/** @type {string} */
this.name = name;
/** @type {string} */
this.mimetype = mimetype;
/** @type {number} */
this.size = size;
/** @type {File} */
this.file = null;
/** @type {boolean} */
this.closed = false;
/** @type {RTCPeerConnection} */
this.pc = null;
/** @type {RTCDataChannel} */
this.dc = null;
/** @type {Array<RTCIceCandidateInit>} */
this.candidates = [];
/** @type {Array<Blob|ArrayBuffer>} */
this.data = [];
/** @type {number} */
this.datalen = 0;
/** @type {(this: TransferredFile, type: string, [data]: string) => void} */
this.onevent = null;
}
/**
* The full id of this file transfer, used as a key in the transferredFiles
* dictionary.
*/
TransferredFile.prototype.fullid = function() {
return this.userid + (this.up ? '+' : '-') + this.id;
};
/**
* Retrieve a transferred file from the transferredFiles dictionary.
*
* @param {string} userid
* @param {string} fileid
* @param {boolean} up
* @returns {TransferredFile}
*/
ServerConnection.prototype.getTransferredFile = function(userid, fileid, up) {
return this.transferredFiles[userid + (up ? '+' : '-') + fileid];
};
/**
* Close a file transfer and remove it from the transferredFiles dictionary.
* Do not call this, call 'cancel' instead.
*/
TransferredFile.prototype.close = function() {
let f = this;
if(f.state === 'closed')
return;
if(f.state !== 'done' && f.state !== 'cancelled')
console.warn(
`TransferredFile.close called in unexpected state ${f.state}`,
);
if(f.dc) {
f.dc.onclose = null;
f.dc.onerror = null;
f.dc.onmessage = null;
}
if(f.pc)
f.pc.close();
f.dc = null;
f.pc = null;
f.data = [];
f.datalen = 0;
delete(f.sc.transferredFiles[f.fullid()]);
f.event('closed');
}
/**
* Buffer a chunk of data received during a file transfer. Do not call this.
*
* @param {Blob|ArrayBuffer} data
*/
TransferredFile.prototype.bufferData = function(data) {
let f = this;
if(f.up)
throw new Error('buffering data in the wrong direction');
if(data instanceof Blob) {
f.datalen += data.size;
} else if(data instanceof ArrayBuffer) {
f.datalen += data.byteLength;
} else {
throw new Error('unexpected type for received data');
}
f.data.push(data);
}
/**
* Retreive the data buffered during a file transfer. Don't call this.
*
* @returns {Blob}
*/
TransferredFile.prototype.getBufferedData = function() {
let f = this;
if(f.up)
throw new Error('buffering data in wrong direction');
let blob = new Blob(f.data, {type: f.mimetype});
if(blob.size != f.datalen)
throw new Error('Inconsistent data size');
f.data = [];
f.datalen = 0;
return blob;
}
/**
* Set the file's state, and call the onevent callback.
*
* This calls the callback even if the state didn't change, which is
* useful if the client needs to display a progress bar.
*
* @param {string} state
* @param {any} [data]
*/
TransferredFile.prototype.event = function(state, data) {
let f = this;
f.state = state;
if(f.onevent)
f.onevent.call(f, state, data);
}
/**
* Cancel a file transfer.
*
* Depending on the state, this will either forcibly close the connection,
* send a handshake, or do nothing. It will set the state to cancelled.
*
* @param {string|Error} [data]
*/
TransferredFile.prototype.cancel = function(data) {
let f = this;
if(f.state === 'closed')
return;
if(f.state !== '' && f.state !== 'done' && f.state !== 'cancelled') {
let m = {
type: f.up ? 'cancel' : 'reject',
id: f.id,
};
if(data)
m.message = data.toString();
f.sc.userMessage('filetransfer', f.userid, m);
}
if(f.state !== 'done' && f.state !== 'cancelled')
f.event('cancelled', data);
f.close();
}
/**
* Forcibly terminate a file transfer.
*
* This is like cancel, but will not attempt to handshake.
* Use cancel instead of this, unless you know what you are doing.
*
* @param {string|Error} [data]
*/
TransferredFile.prototype.fail = function(data) {
let f = this;
if(f.state === 'done' || f.state === 'cancelled' || f.state === 'closed')
return;
f.event('cancelled', data);
f.close();
}
/**
* Initiate a file upload.
*
* This will cause the onfiletransfer callback to be called, at which
* point you should set up the onevent callback.
*
* @param {string} id
* @param {File} file
*/
ServerConnection.prototype.sendFile = function(id, file) {
let sc = this;
let fileid = newRandomId();
let user = sc.users[id];
if(!user)
throw new Error('offering upload to unknown user');
let f = new TransferredFile(
sc, id, fileid, true, user.username, file.name, file.type, file.size,
);
f.file = file;
try {
if(sc.onfiletransfer)
sc.onfiletransfer.call(sc, f);
else
throw new Error('this client does not implement file transfer');
} catch(e) {
f.cancel(e);
return;
}
sc.transferredFiles[f.fullid()] = f;
sc.userMessage('filetransfer', id, {
type: 'invite',
id: fileid,
name: f.name,
size: f.size,
mimetype: f.mimetype,
});
f.event('inviting');
}
/**
* Receive a file.
*
* Call this after the onfiletransfer callback has yielded an incoming
* file (up field set to false). If you wish to reject the file transfer,
* call cancel instead.
*/
TransferredFile.prototype.receive = async function() {
let f = this;
if(f.up)
throw new Error('Receiving in wrong direction');
if(f.pc)
throw new Error('Download already in progress');
let pc = new RTCPeerConnection(serverConnection.getRTCConfiguration());
if(!pc) {
let err = new Error("Couldn't create peer connection");
f.fail(err);
return;
}
f.pc = pc;
f.event('connecting');
f.candidates = [];
pc.onsignalingstatechange = function(e) {
if(pc.signalingState === 'stable') {
f.candidates.forEach(c => pc.addIceCandidate(c).catch(console.warn));
f.candidates = [];
}
};
pc.onicecandidate = function(e) {
serverConnection.userMessage('filetransfer', f.userid, {
type: 'downice',
id: f.id,
candidate: e.candidate,
});
};
f.dc = pc.createDataChannel('file');
f.data = [];
f.datalen = 0;
f.dc.onclose = function(e) {
f.cancel('remote peer closed connection');
};
f.dc.onmessage = function(e) {
f.receiveData(e.data).catch(e => f.cancel(e));
};
f.dc.onerror = function(e) {
/** @ts-ignore */
let err = e.error;
f.cancel(err)
};
let offer = await pc.createOffer();
if(!offer) {
f.cancel(new Error("Couldn't create offer"));
return;
}
await pc.setLocalDescription(offer);
f.sc.userMessage('filetransfer', f.userid, {
type: 'offer',
id: f.id,
sdp: pc.localDescription.sdp,
});
}
/**
* Negotiate a file transfer on the sender side. Don't call this.
*
* @param {string} sdp
*/
TransferredFile.prototype.answer = async function(sdp) {
let f = this;
if(!f.up)
throw new Error('Sending file in wrong direction');
if(f.pc)
throw new Error('Transfer already in progress');
let pc = new RTCPeerConnection(serverConnection.getRTCConfiguration());
if(!pc) {
let err = new Error("Couldn't create peer connection");
f.fail(err);
return;
}
f.pc = pc;
f.event('connecting');
f.candidates = [];
pc.onicecandidate = function(e) {
serverConnection.userMessage('filetransfer', f.userid, {
type: 'upice',
id: f.id,
candidate: e.candidate,
});
};
pc.onsignalingstatechange = function(e) {
if(pc.signalingState === 'stable') {
f.candidates.forEach(c => pc.addIceCandidate(c).catch(console.warn));
f.candidates = [];
}
};
pc.ondatachannel = function(e) {
if(f.dc) {
f.cancel(new Error('Duplicate datachannel'));
return;
}
f.dc = /** @type{RTCDataChannel} */(e.channel);
f.dc.onclose = function(e) {
f.cancel('remote peer closed connection');
};
f.dc.onerror = function(e) {
/** @ts-ignore */
let err = e.error;
f.cancel(err);
}
f.dc.onmessage = function(e) {
if(e.data === 'done' && f.datalen === f.size) {
f.event('done');
f.dc.onclose = null;
f.dc.onerror = null;
f.close();
} else {
f.cancel(new Error('unexpected data from receiver'));
}
}
f.send().catch(e => f.cancel(e));
};
await pc.setRemoteDescription({
type: 'offer',
sdp: sdp,
});
let answer = await pc.createAnswer();
if(!answer)
throw new Error("Couldn't create answer");
await pc.setLocalDescription(answer);
serverConnection.userMessage('filetransfer', f.userid, {
type: 'answer',
id: f.id,
sdp: pc.localDescription.sdp,
});
f.event('connected');
}
/**
* Transfer file data. Don't call this, it is called automatically
* after negotiation completes.
*/
TransferredFile.prototype.send = async function() {
let f = this;
if(!f.up)
throw new Error('sending in wrong direction');
let r = f.file.stream().getReader();
f.dc.bufferedAmountLowThreshold = 65536;
async function write(a) {
while(f.dc.bufferedAmount > f.dc.bufferedAmountLowThreshold) {
await new Promise((resolve, reject) => {
if(!f.dc) {
reject(new Error('File is closed.'));
return;
}
f.dc.onbufferedamountlow = function(e) {
if(!f.dc) {
reject(new Error('File is closed.'));
return;
}
f.dc.onbufferedamountlow = null;
resolve();
}
});
}
f.dc.send(a);
f.datalen += a.length;
// we're already in the connected state, but invoke callbacks to
// that the application can display progress
f.event('connected');
}
while(true) {
let v = await r.read();
if(v.done)
break;
let data = v.value;
if(!(data instanceof Uint8Array))
throw new Error('Unexpected type for chunk');
/* Base SCTP only supports up to 16kB data chunks. There are
extensions to handle larger chunks, but they don't interoperate
between browsers, so we chop the file into small pieces. */
if(data.length <= 16384) {
await write(data);
} else {
for(let i = 0; i < v.value.length; i += 16384) {
let d = new Uint8Array(
data.buffer, i, Math.min(16384, data.length - i),
);
await write(d);
}
}
}
}
/**
* @param {string} sdp
*/
TransferredFile.prototype.receiveFile = async function(sdp) {
let f = this;
if(f.up)
throw new Error('Receiving in wrong direction');
await f.pc.setRemoteDescription({
type: 'answer',
sdp: sdp,
});
f.event('connected');
}
/**
* @param {Blob|ArrayBuffer} data
*/
TransferredFile.prototype.receiveData = async function(data) {
let f = this;
if(f.up)
throw new Error('Receiving in wrong direction');
f.bufferData(data);
if(f.datalen < f.size) {
f.event('connected');
return;
}
f.dc.onmessage = null;
if(f.datalen != f.size) {
f.cancel('unexpected file size');
return;
}
let blob = f.getBufferedData();
f.event('done', blob);
await new Promise((resolve, reject) => {
let timer = setTimeout(function(e) { resolve(); }, 2000);
f.dc.onclose = function(e) {
clearTimeout(timer);
resolve();
};
f.dc.onerror = function(e) {
clearTimeout(timer);
resolve();
};
f.dc.send('done');
});
f.close();
}
/**
* @param {string} id
* @param {string} username
* @param {object} message
*/
ServerConnection.prototype.fileTransfer = function(id, username, message) {
let sc = this;
switch(message.type) {
case 'invite': {
let f = new TransferredFile(
sc, id, message.id, false, username,
message.name, message.mimetype, message.size,
);
f.state = 'inviting';
try {
if(sc.onfiletransfer)
sc.onfiletransfer.call(sc, f);
else
f.cancel('this client does not implement file transfer');
} catch(e) {
f.cancel(e);
return;
}
if(f.fullid() in sc.transferredFiles) {
console.error('Duplicate id for file transfer');
f.cancel("duplicate id (this shouldn't happen)");
return;
}
sc.transferredFiles[f.fullid()] = f;
break;
}
case 'offer': {
let f = sc.getTransferredFile(id, message.id, true);
if(!f) {
console.error('Unexpected offer for file transfer');
return;
}
f.answer(message.sdp).catch(e => f.cancel(e));
break;
}
case 'answer': {
let f = sc.getTransferredFile(id, message.id, false);
if(!f) {
console.error('Unexpected answer for file transfer');
return;
}
f.receiveFile(message.sdp).catch(e => f.cancel(e));
break;
}
case 'downice':
case 'upice': {
let f = sc.getTransferredFile(
id, message.id, message.type === 'downice',
);
if(!f || !f.pc) {
console.warn(`Unexpected ${message.type} for file transfer`);
return;
}
if(f.pc.signalingState === 'stable')
f.pc.addIceCandidate(message.candidate).catch(console.warn);
else
f.candidates.push(message.candidate);
break;
}
case 'cancel':
case 'reject': {
let f = sc.getTransferredFile(id, message.id, message.type === 'reject');
if(!f) {
console.error(`Unexpected ${message.type} for file transfer`);
return;
}
f.event('cancelled');
f.close();
break;
}
default:
console.error(`Unknown filetransfer message ${message.type}`);
break;
}
}