Add simple QLearning solver support

Still experimental, it covers very small subset of action domains (just removal from target).

Added a pending test that currently fails

pkg/solver/resolver_test.go

@@ -0,0 +1,150 @@
+// Copyright © 2019 Ettore Di Giacinto <mudler@gentoo.org>
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this program; if not, see <http://www.gnu.org/licenses/>.
+
+package solver_test
+
+import (
+	pkg "github.com/mudler/luet/pkg/package"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	. "github.com/mudler/luet/pkg/solver"
+)
+
+var _ = Describe("Resolver", func() {
+
+	db := pkg.NewInMemoryDatabase(false)
+	dbInstalled := pkg.NewInMemoryDatabase(false)
+	dbDefinitions := pkg.NewInMemoryDatabase(false)
+	s := NewSolver(dbInstalled, dbDefinitions, db)
+
+	BeforeEach(func() {
+		db = pkg.NewInMemoryDatabase(false)
+		dbInstalled = pkg.NewInMemoryDatabase(false)
+		dbDefinitions = pkg.NewInMemoryDatabase(false)
+		s = NewSolver(dbInstalled, dbDefinitions, db)
+	})
+
+	Context("Conflict set", func() {
+		Context("DummyPackageResolver", func() {
+			It("is unsolvable - as we something we ask to install conflict with system stuff", func() {
+				C := pkg.NewPackage("C", "", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{})
+				B := pkg.NewPackage("B", "", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{C})
+				A := pkg.NewPackage("A", "", []*pkg.DefaultPackage{B}, []*pkg.DefaultPackage{})
+
+				for _, p := range []pkg.Package{A, B, C} {
+					_, err := dbDefinitions.CreatePackage(p)
+					Expect(err).ToNot(HaveOccurred())
+				}
+
+				for _, p := range []pkg.Package{C} {
+					_, err := dbInstalled.CreatePackage(p)
+					Expect(err).ToNot(HaveOccurred())
+				}
+
+				solution, err := s.Install([]pkg.Package{A})
+				Expect(len(solution)).To(Equal(0))
+				Expect(err).To(HaveOccurred())
+			})
+		})
+		Context("QLearningResolver", func() {
+			It("will find out that we can install D by ignoring A", func() {
+				s.SetResolver(&QLearningResolver{})
+				C := pkg.NewPackage("C", "", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{})
+				B := pkg.NewPackage("B", "", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{C})
+				A := pkg.NewPackage("A", "", []*pkg.DefaultPackage{B}, []*pkg.DefaultPackage{})
+				D := pkg.NewPackage("D", "", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{})
+
+				for _, p := range []pkg.Package{A, B, C, D} {
+					_, err := dbDefinitions.CreatePackage(p)
+					Expect(err).ToNot(HaveOccurred())
+				}
+
+				for _, p := range []pkg.Package{C} {
+					_, err := dbInstalled.CreatePackage(p)
+					Expect(err).ToNot(HaveOccurred())
+				}
+
+				solution, err := s.Install([]pkg.Package{A, D})
+				Expect(err).ToNot(HaveOccurred())
+
+				Expect(len(solution)).To(Equal(4))
+
+				Expect(solution).To(ContainElement(PackageAssert{Package: A, Value: false}))
+				Expect(solution).To(ContainElement(PackageAssert{Package: B, Value: false}))
+				Expect(solution).To(ContainElement(PackageAssert{Package: C, Value: true}))
+				Expect(solution).To(ContainElement(PackageAssert{Package: D, Value: true}))
+			})
+			PIt("will find out that we can install D by ignoring A", func() {
+				s.SetResolver(&QLearningResolver{})
+				C := pkg.NewPackage("C", "", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{})
+				B := pkg.NewPackage("B", "", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{C})
+				A := pkg.NewPackage("A", "", []*pkg.DefaultPackage{B}, []*pkg.DefaultPackage{})
+				D := pkg.NewPackage("D", "", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{})
+				E := pkg.NewPackage("E", "", []*pkg.DefaultPackage{B}, []*pkg.DefaultPackage{})
+				F := pkg.NewPackage("F", "", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{})
+
+				for _, p := range []pkg.Package{A, B, C, D, E, F} {
+					_, err := dbDefinitions.CreatePackage(p)
+					Expect(err).ToNot(HaveOccurred())
+				}
+
+				for _, p := range []pkg.Package{C} {
+					_, err := dbInstalled.CreatePackage(p)
+					Expect(err).ToNot(HaveOccurred())
+				}
+
+				solution, err := s.Install([]pkg.Package{A, D, E, F}) // D and F should go as they have no deps. A/E should be filtered by QLearn
+				Expect(err).ToNot(HaveOccurred())
+
+				Expect(len(solution)).To(Equal(6))
+
+				Expect(solution).To(ContainElement(PackageAssert{Package: A, Value: false}))
+				Expect(solution).To(ContainElement(PackageAssert{Package: B, Value: false}))
+				Expect(solution).To(ContainElement(PackageAssert{Package: C, Value: true}))
+				Expect(solution).To(ContainElement(PackageAssert{Package: D, Value: true}))
+				Expect(solution).To(ContainElement(PackageAssert{Package: E, Value: true}))
+				Expect(solution).To(ContainElement(PackageAssert{Package: F, Value: true}))
+
+			})
+		})
+
+		Context("DummyPackageResolver", func() {
+			It("cannot find a solution", func() {
+				C := pkg.NewPackage("C", "", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{})
+				B := pkg.NewPackage("B", "", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{C})
+				A := pkg.NewPackage("A", "", []*pkg.DefaultPackage{B}, []*pkg.DefaultPackage{})
+				D := pkg.NewPackage("D", "", []*pkg.DefaultPackage{}, []*pkg.DefaultPackage{})
+
+				for _, p := range []pkg.Package{A, B, C, D} {
+					_, err := dbDefinitions.CreatePackage(p)
+					Expect(err).ToNot(HaveOccurred())
+				}
+
+				for _, p := range []pkg.Package{C} {
+					_, err := dbInstalled.CreatePackage(p)
+					Expect(err).ToNot(HaveOccurred())
+				}
+
+				solution, err := s.Install([]pkg.Package{A, D})
+				Expect(err).To(HaveOccurred())
+
+				Expect(len(solution)).To(Equal(0))
+			})
+
+		})
+	})
+
+})