Qiskit / qiskit / 14274010472

88%

Build Type

push

github

Committed by web-flow

Commit Message

Split DAGCircuit::compose() into Rust and python (#14164)

* Split DAGCircuit::compose() into Rust and python

The DAGCircuit::compose() method was previously implemented using most
of the logic via python. Basically it was all python just implemented
via PyO3 calls. This limited the performance of the function, but also
potentially more importantly meant that we didn't have an internal
Rust mechanism for running dag circuit composition. This commit seeks to
address this by splitting out the Python interface from the rust
implementation and rewriting the internals to operate on the Rust data
model directly instead of going through python. The `DAGCircuit::compose()`
method becomes the rust function for doing composition, and
`DAGCircuit::py_compose()` is the python interface.

Ideally we'd be able to drop the Python token argument from the new
`DAGCircuit::compose()` too, but because of
`DAGCircuit::apply_operation_back()` and handling of Vars this wasn't
worth the effort of using `Python::with_gil()` since we'd
unconditionally need the gil. Once `apply_operation_back()` no longer
needs the GIL, we should be able to drop the py argument from compose
too.

* Fix failing control flow tests

The control flow var handling was assuming that the underlying
instruction objects were copied during a compose() instead of mutated in
place with the updates. This commit corrects the oversight to fix the
failing tests.

* Remove pointless front argument from rust interface

* Lazily instantiate PyVariableMapper

* Update crates/circuit/src/dag_circuit.rs

* Fixes from code review

Run Details

210 of 251 new or added lines in 1 file covered. (83.67%)

3 existing lines in 2 files now uncovered.

72963 of 82841 relevant lines covered (88.08%)

377838.32 hits per line