The function `_get_possible_combinations` generates possibles combinations
for the product template attribute values (ptav) of each product template
attribute line (ptal) of a given product template. It used to iterate over
them using a cartesian product. A combination can be invalid if it
contains two incompatibles ptav. The problem is that it used to filter out
invalid combinations after generating them. It's a problem because there
can be a lot of invalid combinations to filter out before finding a valid
combination. Even before the first valid combination if the first ptav of
the two first ptal are incompatible.
The solution brought by this commit is to reject the invalid combinations
while building them rather than after. It does so by using a cartesian
product implementation with early rejection. The algorithm tests each
ptav when incorporating it in a partial combination and if it's
incompatible, it goes to the next partial combination and thus skips all
combinations starting with the invalid partial combination.
The client that reported the issue has a product template with about 25
ptal with an average of 9 ptav. The ptav of the first ptal was
incompatible with the first ptav of second ptal. It had to build and
filter out 5.76*10^15 ptav before finding the first valid ptav. If we
generate 10^6 ptav by second (it's much less) user would get first ptav
after 182 years. Now it's instantaneous.
opw-2335936
closesodoo/odoo#65809
X-original-commit: 98616c4676aa6ef5507110c0e407a640082abbaf
Signed-off-by: Sébastien Theys (seb) <seb@odoo.com>
Adrien Horgnies
1705a40a9d