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Merge pull request #1028 from amtep/develop 

Fix server crash if client disconnects too soon after connecting
pull/1006/merge
John McLear 2012-09-30 04:22:36 -07:00
parent 3578e36616 2e72a1e489
commit c75941d1e3
1 changed files with 54 additions and 35 deletions
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89
src/node/handler/PadMessageHandler.js
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@ -436,15 +436,22 @@ function handleUserInfoUpdate(client, message)
}
/**
* Handles a USERINFO_UPDATE, that means that a user have changed his color or name. Anyway, we get both informations
* This Method is nearly 90% copied out of the Etherpad Source Code. So I can't tell you what happens here exactly
* Look at https://github.com/ether/pad/blob/master/etherpad/src/etherpad/collab/collab_server.js in the function applyUserChanges()
* Handles a USER_CHANGES message, where the client submits its local
* edits as a changeset.
*
* This handler's job is to update the incoming changeset so that it applies
* to the latest revision, then add it to the pad, broadcast the changes
* to all other clients, and send a confirmation to the submitting client.
*
* This function is based on a similar one in the original Etherpad.
* See https://github.com/ether/pad/blob/master/etherpad/src/etherpad/collab/collab_server.js in the function applyUserChanges()
*
* @param client the client that send this message
* @param message the message from the client
*/
function handleUserChanges(client, message)
{
//check if all ok
// Make sure all required fields are present
if(message.data.baseRev == null)
{
messageLogger.warn("Dropped message, USER_CHANGES Message has no baseRev!");
@ -487,22 +494,23 @@ function handleUserChanges(client, message)
{
//ex. _checkChangesetAndPool
//Copied from Etherpad, don't know what it does exactly
try
{
//this looks like a changeset check, it throws errors sometimes
// Verify that the changeset has valid syntax and is in canonical form
Changeset.checkRep(changeset);
// Verify that the attribute indexes used in the changeset are all
// defined in the accompanying attribute pool.
Changeset.eachAttribNumber(changeset, function(n) {
if (! wireApool.getAttrib(n)) {
throw "Attribute pool is missing attribute "+n+" for changeset "+changeset;
}
});
}
//there is an error in this changeset, so just refuse it
catch(e)
{
console.warn("Can't apply USER_CHANGES "+changeset+", cause it faild checkRep");
// There is an error in this changeset, so just refuse it
console.warn("Can't apply USER_CHANGES "+changeset+", because it failed checkRep");
client.json.send({disconnect:"badChangeset"});
return;
}
@ -515,7 +523,10 @@ function handleUserChanges(client, message)
//ex. applyUserChanges
apool = pad.pool;
r = baseRev;
// The client's changeset might not be based on the latest revision,
// since other clients are sending changes at the same time.
// Update the changeset so that it can be applied to the latest revision.
//https://github.com/caolan/async#whilst
async.whilst(
function() { return r < pad.getHeadRevisionNumber(); },
@ -526,8 +537,13 @@ function handleUserChanges(client, message)
pad.getRevisionChangeset(r, function(err, c)
{
if(ERR(err, callback)) return;
// At this point, both "c" (from the pad) and "changeset" (from the
// client) are relative to revision r - 1. The follow function
// rebases "changeset" so that it is relative to revision r
// and can be applied after "c".
changeset = Changeset.follow(c, changeset, false, apool);
if ((r - baseRev) % 200 == 0) { // don't let the stack get too deep
async.nextTick(callback);
} else {
@ -558,7 +574,8 @@ function handleUserChanges(client, message)
if (correctionChangeset) {
pad.appendRevision(correctionChangeset);
}
// Make sure the pad always ends with an empty line.
if (pad.text().lastIndexOf("\n\n") != pad.text().length-2) {
var nlChangeset = Changeset.makeSplice(pad.text(), pad.text().length-1, 0, "\n");
pad.appendRevision(nlChangeset);
@ -865,6 +882,13 @@ function handleClientReady(client, message)
},
function(callback)
{
//Check that the client is still here. It might have disconnected between callbacks.
if(sessioninfos[client.id] === undefined)
{
callback();
return;
}
//Check if this author is already on the pad, if yes, kick the other sessions!
if(pad2sessions[padIds.padId])
{
@ -879,10 +903,9 @@ function handleClientReady(client, message)
}
//Save in sessioninfos that this session belonges to this pad
var sessionId=String(client.id);
sessioninfos[sessionId].padId = padIds.padId;
sessioninfos[sessionId].readOnlyPadId = padIds.readOnlyPadId;
sessioninfos[sessionId].readonly = padIds.readonly;
sessioninfos[client.id].padId = padIds.padId;
sessioninfos[client.id].readOnlyPadId = padIds.readOnlyPadId;
sessioninfos[client.id].readonly = padIds.readonly;
//check if there is already a pad2sessions entry, if not, create one
if(!pad2sessions[padIds.padId])
@ -891,7 +914,7 @@ function handleClientReady(client, message)
}
//Saves in pad2sessions that this session belongs to this pad
pad2sessions[padIds.padId].push(sessionId);
pad2sessions[padIds.padId].push(client.id);
//prepare all values for the wire
var atext = Changeset.cloneAText(pad.atext);
@ -956,26 +979,22 @@ function handleClientReady(client, message)
clientVars.userName = authorName;
}
if(sessioninfos[client.id] !== undefined)
//If this is a reconnect, we don't have to send the client the ClientVars again
if(message.reconnect == true)
{
//This is a reconnect, so we don't have to send the client the ClientVars again
if(message.reconnect == true)
{
//Save the revision in sessioninfos, we take the revision from the info the client send to us
sessioninfos[client.id].rev = message.client_rev;
}
//This is a normal first connect
else
{
//Send the clientVars to the Client
client.json.send({type: "CLIENT_VARS", data: clientVars});
//Save the revision in sessioninfos
sessioninfos[client.id].rev = pad.getHeadRevisionNumber();
}
//Save the revision and the author id in sessioninfos
sessioninfos[client.id].author = author;
//Save the revision in sessioninfos, we take the revision from the info the client send to us
sessioninfos[client.id].rev = message.client_rev;
}
//This is a normal first connect
else
{
//Send the clientVars to the Client
client.json.send({type: "CLIENT_VARS", data: clientVars});
//Save the current revision in sessioninfos, should be the same as in clientVars
sessioninfos[client.id].rev = pad.getHeadRevisionNumber();
}
sessioninfos[client.id].author = author;
//prepare the notification for the other users on the pad, that this user joined
var messageToTheOtherUsers = {