Remove variable sources

Instead of a variable source make Deppy accept
a slice of variables as an input.

Signed-off-by: Mikalai Radchuk <mradchuk@redhat.com>

cmd/dimacs/cmd.go

@@ -1,7 +1,6 @@
 package dimacs
 
 import (
-	"context"
 	"errors"
 	"fmt"
 	"os"
@@ -53,15 +52,19 @@ func solve(path string) error {
 	}
 
 	// build solver
-	so := solver.NewDeppySolver(NewDimacsVariableSource(dimacs))
+	so := solver.NewDeppySolver()
 
 	// get solution
-	solution, err := so.Solve(context.Background(), solver.AddAllVariablesToSolution())
+	vars, err := GenerateVariables(dimacs)
+	if err != nil {
+		return fmt.Errorf("error generating variables: %s", err)
+	}
+	solution, err := so.Solve(vars)
 	if err != nil {
 		fmt.Printf("no solution found: %s\n", err)
 	} else {
 		fmt.Println("solution found:")
-		for _, variable := range solution.AllVariables() {
+		for _, variable := range vars {
 			fmt.Printf("%s = %t\n", variable.Identifier(), solution.IsSelected(variable.Identifier()))
 		}
 	}

cmd/dimacs/dimacs_constraints.go

@@ -1,38 +1,25 @@
 package dimacs
 
 import (
-	"context"
 	"strings"
 
 	"github.com/operator-framework/deppy/pkg/deppy"
 	"github.com/operator-framework/deppy/pkg/deppy/constraint"
 	"github.com/operator-framework/deppy/pkg/deppy/input"
 )
 
-var _ input.VariableSource = &ConstraintGenerator{}
+func GenerateVariables(dimacs *Dimacs) ([]deppy.Variable, error) {
+	varMap := make(map[deppy.Identifier]*input.SimpleVariable, len(dimacs.variables))
+	variables := make([]deppy.Variable, 0, len(dimacs.variables))
 
-type ConstraintGenerator struct {
-	dimacs *Dimacs
-}
-
-func NewDimacsVariableSource(dimacs *Dimacs) *ConstraintGenerator {
-	return &ConstraintGenerator{
-		dimacs: dimacs,
-	}
-}
-
-func (d *ConstraintGenerator) GetVariables(_ context.Context) ([]deppy.Variable, error) {
-	varMap := make(map[deppy.Identifier]*input.SimpleVariable, len(d.dimacs.variables))
-	variables := make([]deppy.Variable, 0, len(d.dimacs.variables))
-
-	for _, id := range d.dimacs.variables {
+	for _, id := range dimacs.variables {
 		variable := input.NewSimpleVariable(deppy.IdentifierFromString(id))
 		variables = append(variables, variable)
 		varMap[variable.Identifier()] = variable
 	}
 
 	// create constraints out of the clauses
-	for _, clause := range d.dimacs.clauses {
+	for _, clause := range dimacs.clauses {
 		terms := strings.Split(clause, " ")
 		if len(terms) == 0 {
 			continue

cmd/dimacs/dimacs_test.go

@@ -2,7 +2,6 @@ package dimacs_test
 
 import (
 	"bytes"
-	"context"
 	"testing"
 
 	"github.com/operator-framework/deppy/pkg/deppy"
@@ -43,10 +42,7 @@ var _ = Describe("Dimacs Variable Source", func() {
 		problem := "p cnf 3 1\n1 2 3 0\n"
 		d, err := dimacs.NewDimacs(bytes.NewReader([]byte(problem)))
 		Expect(err).ToNot(HaveOccurred())
-		vs := dimacs.NewDimacsVariableSource(d)
-		ctx, cancel := context.WithCancel(context.Background())
-		defer cancel()
-		variables, err := vs.GetVariables(ctx)
+		variables, err := dimacs.GenerateVariables(d)
 		Expect(err).ToNot(HaveOccurred())
 		Expect(variables).To(HaveLen(3))
 

cmd/sudoku/cmd.go

@@ -1,7 +1,6 @@
 package sudoku
 
 import (
-	"context"
 	"fmt"
 
 	"github.com/spf13/cobra"
@@ -23,11 +22,14 @@ func NewSudokuCommand() *cobra.Command {
 
 func solve() error {
 	// build solver
-	sudoku := &Sudoku{}
-	so := solver.NewDeppySolver(sudoku)
+	so := solver.NewDeppySolver()
 
 	// get solution
-	solution, err := so.Solve(context.Background())
+	vars, err := GenerateVariables()
+	if err != nil {
+		return err
+	}
+	solution, err := so.Solve(vars)
 	if err != nil {
 		fmt.Println("no solution found")
 	} else {

cmd/sudoku/sudoku.go

@@ -1,7 +1,6 @@
 package sudoku
 
 import (
-	"context"
 	"fmt"
 	"math/rand"
 
@@ -10,22 +9,14 @@ import (
 	"github.com/operator-framework/deppy/pkg/deppy/input"
 )
 
-var _ input.VariableSource = &Sudoku{}
-
-type Sudoku struct{}
-
 func GetID(row int, col int, num int) deppy.Identifier {
 	n := num
 	n += col * 9
 	n += row * 81
 	return deppy.Identifier(fmt.Sprintf("%03d", n))
 }
 
-func NewSudoku() *Sudoku {
-	return &Sudoku{}
-}
-
-func (s Sudoku) GetVariables(_ context.Context) ([]deppy.Variable, error) {
+func GenerateVariables() ([]deppy.Variable, error) {
 	// adapted from: https://github.com/go-air/gini/blob/871d828a26852598db2b88f436549634ba9533ff/sudoku_test.go#L10
 	variables := make(map[deppy.Identifier]*input.SimpleVariable, 0)
 	inorder := make([]deppy.Variable, 0)

internal/solver/bench_test.go

@@ -1,7 +1,6 @@
 package solver
 
 import (
-	"context"
 	"math/rand"
 	"strconv"
 	"testing"
@@ -73,7 +72,7 @@ func BenchmarkSolve(b *testing.B) {
 		if err != nil {
 			b.Fatalf("failed to initialize solver: %s", err)
 		}
-		_, err = s.Solve(context.Background())
+		_, err = s.Solve()
 		if err != nil {
 			b.Fatalf("failed to initialize solver: %s", err)
 		}

internal/solver/solve.go

@@ -15,7 +15,7 @@ import (
 var ErrIncomplete = errors.New("cancelled before a solution could be found")
 
 type Solver interface {
-	Solve(context.Context) ([]deppy.Variable, error)
+	Solve() ([]deppy.Variable, error)
 }
 
 type solver struct {
@@ -35,7 +35,7 @@ const (
 // containing only those Variables that were selected for
 // installation. If no solution is possible, or if the provided
 // Context times out or is cancelled, an error is returned.
-func (s *solver) Solve(_ context.Context) ([]deppy.Variable, error) {
+func (s *solver) Solve() ([]deppy.Variable, error) {
 	result, err := s.solve()
 
 	// This likely indicates a bug, so discard whatever

internal/solver/solve_test.go

@@ -2,7 +2,6 @@ package solver
 
 import (
 	"bytes"
-	"context"
 	"fmt"
 	"testing"
 
@@ -296,7 +295,7 @@ func TestSolve(t *testing.T) {
 				t.Fatalf("failed to initialize solver: %s", err)
 			}
 
-			installed, err := s.Solve(context.TODO())
+			installed, err := s.Solve()
 
 			var ids []deppy.Identifier
 			for _, variable := range installed {

pkg/deppy/solver/solver.go

@@ -1,24 +1,21 @@
 package solver
 
 import (
-	"context"
 	"errors"
 
 	"github.com/operator-framework/deppy/internal/solver"
 	"github.com/operator-framework/deppy/pkg/deppy"
-	"github.com/operator-framework/deppy/pkg/deppy/input"
 )
 
 // TODO: should disambiguate between solver errors due to constraints
-//       and other generic errors (e.g. entity source not reachable, etc.)
+//       and other generic errors
 
 // Solution is returned by the Solver when the internal solver executed successfully.
 // A successful execution of the solver can still end in an error when no solution can
 // be found.
 type Solution struct {
 	err       error
 	selection map[deppy.Identifier]deppy.Variable
-	variables []deppy.Variable
 }
 
 // Error returns the resolution error in case the problem is unsat
@@ -40,66 +37,21 @@ func (s *Solution) IsSelected(identifier deppy.Identifier) bool {
 	return ok
 }
 
-// AllVariables returns all the variables that were considered by the solver to obtain (or not)
-// a solution. Note: This is only be present if the AddAllVariablesToSolution option is passed in to the
-// Solve call that generated the solution.
-func (s *Solution) AllVariables() []deppy.Variable {
-	return s.variables
-}
-
-type solutionOptions struct {
-	addVariablesToSolution bool
-}
-
-func (s *solutionOptions) apply(options ...Option) *solutionOptions {
-	for _, applyOption := range options {
-		applyOption(s)
-	}
-	return s
-}
-
-func defaultSolutionOptions() *solutionOptions {
-	return &solutionOptions{
-		addVariablesToSolution: false,
-	}
-}
-
-type Option func(solutionOptions *solutionOptions)
-
-// AddAllVariablesToSolution is a Solve option that instructs the solver to include
-// all the variables considered to the Solution it produces
-func AddAllVariablesToSolution() Option {
-	return func(solutionOptions *solutionOptions) {
-		solutionOptions.addVariablesToSolution = true
-	}
-}
-
-// DeppySolver is a simple solver implementation that takes an entity source group and a constraint aggregator
+// DeppySolver is a simple solver implementation that takes a slice of variables
 // to produce a Solution (or error if no solution can be found)
-type DeppySolver struct {
-	variableSource input.VariableSource
-}
+type DeppySolver struct{}
 
-func NewDeppySolver(variableSource input.VariableSource) *DeppySolver {
-	return &DeppySolver{
-		variableSource: variableSource,
-	}
+func NewDeppySolver() *DeppySolver {
+	return &DeppySolver{}
 }
 
-func (d DeppySolver) Solve(ctx context.Context, options ...Option) (*Solution, error) {
-	solutionOpts := defaultSolutionOptions().apply(options...)
-
-	vars, err := d.variableSource.GetVariables(ctx)
-	if err != nil {
-		return nil, err
-	}
-
+func (d DeppySolver) Solve(vars []deppy.Variable) (*Solution, error) {
 	satSolver, err := solver.NewSolver(solver.WithInput(vars))
 	if err != nil {
 		return nil, err
 	}
 
-	selection, err := satSolver.Solve(ctx)
+	selection, err := satSolver.Solve()
 	if err != nil && !errors.As(err, &deppy.NotSatisfiable{}) {
 		return nil, err
 	}
@@ -116,9 +68,5 @@ func (d DeppySolver) Solve(ctx context.Context, options ...Option) (*Solution, e
 		solution.err = unsatError
 	}
 
-	if solutionOpts.addVariablesToSolution {
-		solution.variables = vars
-	}
-
 	return solution, nil
 }