Hello group,
I was wondering what your policy is towards changing PHP's public
interface in order to accomodate new features.
I'm looking into extending the PHP InterBase extension to support
multi-database (2-phase committed) transactions. This would result in
the following implications:
-
a transaction handle no longer uniquely identifies a link handle ->
internal
data structures will have to be changed a little, not a real problem -
a query against a multi-DB transaction would have to know both the link
and transaction handle -> this is more of a problem, because the functions
ibase_query() and ibase_prepare() expect a 'link_trans' argument, which is
either a le_[p]link or a le_trans, and not both.
Therefore, in order to accomodate this, I would like to suggest making the
following (backward compatible) change to the interface into :
ibase_query([ [int link_identifier [, int trans_identifier]], string query
[, int bind_args]])
ibase_prepare([ [int link_identifier [, int trans_identifier]], string
query])
The Zend argument type inference system should then distinguish between the
cases where
both a db & trans handle are passed, only one of these handles is passed or
neither. This would
allow existing code to continue working unchanged.
A further extension could be to allow different transaction parameters for
each link the transaction
connects to. (Example: transaction connects to db1 R/W and to db2 R/O
simultaneously) This would
require changing the interface of ibase_trans() to
int ibase_trans ( [int trans_args [, int link_identifier]] | [int
trans_args, int link_identifier] *])
which is again a backward compatible change, because formally, the function
only accepts two parameters
currently. However, the existing code does accept multiple le_[p]link
arguments, but ignores them.
The application I'm going to use this for does not require the latter, so my
main concern is the first part of
the modification.
Ard Biesheuvel
a.k.biesheuvel
<at/>
its.tudelft.nl