feat: add solver (#361)

This PR achieves functionality described in #353
TODO:
- [x] Test

py-rattler/Cargo.toml

@@ -20,7 +20,7 @@ rattler_conda_types = { path = "../crates/rattler_conda_types", default-features
 rattler_networking = { path = "../crates/rattler_networking", default-features = false }
 rattler_shell = { path = "../crates/rattler_shell", default-features = false }
 rattler_virtual_packages = { path = "../crates/rattler_virtual_packages" }
-rattler_solve = { path = "../crates/rattler_solve" }
+rattler_solve = { path = "../crates/rattler_solve", features = ["resolvo"] }
 
 pyo3 = { version = "0.19", features = [
     "abi3-py38",

py-rattler/pixi.toml

@@ -12,6 +12,7 @@ license = "BSD-3-Clause"
 
 [tasks]
 build = "PIP_REQUIRE_VIRTUALENV=false maturin develop"
+build-release = "PIP_REQUIRE_VIRTUALENV=false maturin develop --release"
 test = { cmd = "pytest --doctest-modules", depends_on = ["build"] }
 fmt-python = "black ."
 fmt-rust = "cargo fmt --all"
@@ -34,3 +35,6 @@ black = "~=23.7.0"
 ruff = "~=0.0.285"
 mypy = "~=1.5.1"
 pytest-asyncio = "0.21.1.*"
+
+[target.linux-64.dependencies]
+patchelf = "~=0.17.2"

py-rattler/rattler/__init__.py

@@ -12,6 +12,8 @@
 from rattler.virtual_package import GenericVirtualPackage, VirtualPackage
 from rattler.package import PackageName
 from rattler.prefix import PrefixRecord, PrefixPaths
+from rattler.solver import solve
+from rattler.platform import Platform
 
 __all__ = [
     "Version",
@@ -32,4 +34,6 @@
     "PrefixRecord",
     "PrefixPaths",
     "SparseRepoData",
+    "solve",
+    "Platform",
 ]

py-rattler/rattler/channel/channel.py

@@ -6,7 +6,9 @@
 
 
 class Channel:
-    def __init__(self, name: str, channel_configuration: ChannelConfig) -> None:
+    def __init__(
+        self, name: str, channel_configuration: ChannelConfig = ChannelConfig()
+    ) -> None:
         """
         Create a new channel.
 

py-rattler/rattler/solver/__init__.py

@@ -0,0 +1,3 @@
+from rattler.solver.solver import solve
+
+__all__ = ["solve"]

py-rattler/rattler/solver/solver.py

@@ -0,0 +1,58 @@
+from __future__ import annotations
+from typing import List, Optional
+from rattler.match_spec.match_spec import MatchSpec
+
+from rattler.rattler import py_solve
+from rattler.repo_data.record import RepoDataRecord
+from rattler.repo_data.sparse import SparseRepoData
+from rattler.virtual_package.generic import GenericVirtualPackage
+
+
+def solve(
+    specs: List[MatchSpec],
+    available_packages: List[SparseRepoData],
+    locked_packages: Optional[List[RepoDataRecord]] = None,
+    pinned_packages: Optional[List[RepoDataRecord]] = None,
+    virtual_packages: Optional[List[GenericVirtualPackage]] = None,
+) -> List[RepoDataRecord]:
+    """
+    Resolve the dependencies and return the `RepoDataRecord`s
+    that should be present in the environment.
+
+    Arguments:
+        specs: A list of matchspec to solve.
+        available_packages: A list of RepoData to use for solving the `specs`.
+        locked_packages: Records of packages that are previously selected.
+                         If the solver encounters multiple variants of a single
+                         package (identified by its name), it will sort the records
+                         and select the best possible version. However, if there
+                         exists a locked version it will prefer that variant instead.
+                         This is useful to reduce the number of packages that are
+                         updated when installing new packages. Usually you add the
+                         currently installed packages or packages from a lock-file here.
+        pinned_packages: Records of packages that are previously selected and CANNOT
+                         be changed. If the solver encounters multiple variants of
+                         a single package (identified by its name), it will sort the
+                         records and select the best possible version. However, if
+                         there is a variant available in the `pinned_packages` field it
+                         will always select that version no matter what even if that
+                         means other packages have to be downgraded.
+        virtual_packages: A list of virtual packages considered active.
+
+    Returns:
+        Resolved list of `RepoDataRecord`s.
+    """
+
+    return [
+        RepoDataRecord._from_py_record(solved_package)
+        for solved_package in py_solve(
+            [spec._match_spec for spec in specs],
+            [package._sparse for package in available_packages],
+            [package._record for package in locked_packages or []],
+            [package._record for package in pinned_packages or []],
+            [
+                v_package._generic_virtual_package
+                for v_package in virtual_packages or []
+            ],
+        )
+    ]

py-rattler/src/error.rs

@@ -8,6 +8,7 @@ use rattler_conda_types::{
 };
 use rattler_repodata_gateway::fetch::FetchRepoDataError;
 use rattler_shell::activation::ActivationError;
+use rattler_solve::SolveError;
 use rattler_virtual_packages::DetectVirtualPackageError;
 use thiserror::Error;
 
@@ -38,6 +39,10 @@ pub enum PyRattlerError {
     DetectVirtualPackageError(#[from] DetectVirtualPackageError),
     #[error(transparent)]
     IoError(#[from] io::Error),
+    #[error(transparent)]
+    SolverError(#[from] SolveError),
+    #[error("invalid 'SparseRepoData' object found")]
+    InvalidSparseDataError,
 }
 
 impl From<PyRattlerError> for PyErr {
@@ -69,6 +74,10 @@ impl From<PyRattlerError> for PyErr {
                 DetectVirtualPackageException::new_err(err.to_string())
             }
             PyRattlerError::IoError(err) => IoException::new_err(err.to_string()),
+            PyRattlerError::SolverError(err) => SolverException::new_err(err.to_string()),
+            PyRattlerError::InvalidSparseDataError => InvalidSparseDataException::new_err(
+                PyRattlerError::InvalidSparseDataError.to_string(),
+            ),
         }
     }
 }
@@ -85,3 +94,5 @@ create_exception!(exceptions, FetchRepoDataException, PyException);
 create_exception!(exceptions, CacheDirException, PyException);
 create_exception!(exceptions, DetectVirtualPackageException, PyException);
 create_exception!(exceptions, IoException, PyException);
+create_exception!(exceptions, SolverException, PyException);
+create_exception!(exceptions, InvalidSparseDataException, PyException);

py-rattler/src/lib.rs

@@ -9,6 +9,7 @@ mod platform;
 mod prefix_record;
 mod repo_data;
 mod shell;
+mod solver;
 mod version;
 mod virtual_package;
 
@@ -34,6 +35,7 @@ use pyo3::prelude::*;
 
 use platform::{PyArch, PyPlatform};
 use shell::{PyActivationResult, PyActivationVariables, PyActivator, PyShellEnum};
+use solver::py_solve;
 use virtual_package::PyVirtualPackage;
 
 #[pymodule]
@@ -71,6 +73,9 @@ fn rattler(py: Python, m: &PyModule) -> PyResult<()> {
     m.add_class::<PyPrefixRecord>().unwrap();
     m.add_class::<PyPrefixPaths>().unwrap();
 
+    m.add_function(wrap_pyfunction!(py_solve, m).unwrap())
+        .unwrap();
+
     // Exceptions
     m.add(
         "InvalidVersionError",

py-rattler/src/match_spec.rs

@@ -11,7 +11,7 @@ use crate::{
 #[repr(transparent)]
 #[derive(Clone)]
 pub struct PyMatchSpec {
-    inner: MatchSpec,
+    pub(crate) inner: MatchSpec,
 }
 
 impl From<MatchSpec> for PyMatchSpec {