- From: Jonas Sicking <jonas@sicking.cc>
- Date: Fri, 14 Oct 2011 14:43:07 -0700
- To: Israel Hilerio <israelh@microsoft.com>
- Cc: "ben turner (bent.mozilla@gmail.com)" <bent.mozilla@gmail.com>, "public-webapps@w3.org" <public-webapps@w3.org>, Tom Bolds <thombo@microsoft.com>, Adam Herchenroether <aherchen@microsoft.com>, Victor Ngo <vicngo@microsoft.com>
On Fri, Oct 14, 2011 at 2:27 PM, Israel Hilerio <israelh@microsoft.com> wrote: > On Monday, October 10, 2011 10:15 AM, Israel Hilerio wrote: >> On Monday, October 10, 2011 9:46 AM, Jonas Sicking wrote: >> > On Fri, Oct 7, 2011 at 11:51 AM, Israel Hilerio >> > <israelh@microsoft.com> >> > wrote: >> > > On Thursday, October 06, 2011 5:44 PM, Jonas Sicking wrote: >> > >> Hi All, >> > >> >> > >> In both the Firefox and the Chrome implementation you can pass an >> > >> empty array to IDBDatabase.transaction in order to create a >> > >> transaction which has a scope that covers all objectStores in the >> > >> database. I.e. you can do something like: >> > >> >> > >> trans = db.transaction([]); >> > >> trans.objectStore(<any objectstore here>); >> > >> >> > >> (Note that this is *not* a dynamic scoped transaction, it's still a >> > >> static scope that covers the whole database). >> > >> >> > >> In other words, these implementations treat the following two lines >> > >> as >> > >> equivalent: >> > >> >> > >> trans = db.transaction([]); >> > >> trans = db.transaction(db.objectStoreNames); >> > >> >> > >> This, however, is not specified behavior. According to the spec as >> > >> it is now the transaction should be created with an empty scope. >> > >> >> > >> I suspect both Mozilla and Google implemented it this way because >> > >> we had discussions about this syntax on the list. However >> > >> apparently this syntax never made it into the spec. I don't recall why. >> > >> >> > >> I'm personally not a big fan of this syntax. My concern is that it >> > >> makes it easier to create a widely scoped transaction which has >> > >> less ability to run in parallel with other transactions, than to >> > >> create a transaction with as narrow scope as possible. And passing >> > db.objectStoreNames is always possible. >> > >> >> > >> What do people think we should do? Should we add this behavior to >> > >> the spec? Or are implementations willing to remove it? >> > >> >> > >> / Jonas >> > >> >> > > >> > > Our implementation interprets the empty array as an empty scope. We >> > allow the transaction to be created but we throw a NOT_FOUND_ERR when >> > trying to access any object stores. >> > > I vote for not having this behavior :-). >> > >> > Hi Israel, >> > >> > I just realized that I might have misinterpreted your response. >> > >> > Are you saying that you think that passing an empty-array should >> > produce a transaction with an empty scope (like in IEs implementation >> > and as described by the spec currently), or a transaction with every >> > objectStore in scope (like in Firefox and chrome)? >> > >> > / Jonas >> > >> >> We don't do it like FF or chrome. We create the transaction but it has an >> empty scope transaction. Therefore, whenever you try to access an object >> store we throw an exception. Based on what Hans said, it seems we're all in >> agreement. >> >> Also, I like Ben's suggestion of not allowing these transactions to be created in >> the first place and throwing an exception during their creation. >> >> Israel >> > > What type of exception should we throw when trying to create a transaction with an empty scope (NotFoundError, TypeError, or other)? Either of those would work for me. / Jonas
Received on Friday, 14 October 2011 21:44:12 UTC