gps: source cache: protobuf integration

.codeclimate.yml

@@ -15,3 +15,4 @@ exclude_paths:
   - internal/gps/_testdata
   - cmd/dep/testdata
   - testdata
+  - internal/gps/internal/pb

Gopkg.toml

@@ -22,3 +22,11 @@
 [[constraint]]
   name = "github.com/boltdb/bolt"
   version = "1.0.0"
+
+[[constraint]]
+  name = "github.com/jmank88/nuts"
+  version = "0.2.0"
+
+[[constraint]]
+  name = "github.com/golang/protobuf"
+  branch = "master"

hack/validate-licence.bash

@@ -8,5 +8,5 @@
 set -e
 
 go build ./hack/licenseok
-find . -path ./vendor -prune -o -type f -name "*.go"\
+find . -path ./vendor -prune -o -regex ".+\.pb\.go$" -prune -o -type f -regex ".*\.\(go\|proto\)$"\
  -printf '%P\n' | xargs ./licenseok

internal/gps/constraint_test.go

@@ -8,6 +8,8 @@ import (
 	"fmt"
 	"testing"
 
+	"github.com/golang/dep/internal/gps/internal/pb"
+	"github.com/golang/protobuf/proto"
 	"github.com/pkg/errors"
 )
 
@@ -962,3 +964,44 @@ func testSemverConstraint(t *testing.T, body string) Constraint {
 	}
 	return c
 }
+
+func TestConstraintEncoding(t *testing.T) {
+	for _, test := range []struct {
+		name string
+		c    Constraint
+	}{
+		{"defaultBranch", newDefaultBranch("test")},
+		{"branch", NewBranch("test")},
+		{"ver", NewVersion("test")},
+		{"semver", testSemverConstraint(t, "^1.0.0")},
+		{"rev", Revision("test")},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			var msg pb.Constraint
+			test.c.copyTo(&msg)
+			b, err := proto.Marshal(&msg)
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			if err := proto.Unmarshal(b, &msg); err != nil {
+				t.Fatal(err)
+			}
+			got, err := constraintFromCache(&msg)
+			if err != nil {
+				t.Error("failed to decode:", err)
+			} else if !got.identical(test.c) {
+				t.Errorf("decoded non-identical Constraint:\n\t(GOT): %#v\n\t(WNT): %#v", got, test.c)
+			}
+
+			if _, ok := test.c.(UnpairedVersion); ok {
+				got, err := unpairedVersionFromCache(&msg)
+				if err != nil {
+					t.Error("failed to decode:", err)
+				} else if !got.identical(test.c) {
+					t.Errorf("decoded non-identical UnpairedVersion:\n\t(GOT): %#v\n\t(WNT): %#v", got, test.c)
+				}
+			}
+		})
+	}
+}

internal/gps/constraints.go

@@ -9,6 +9,7 @@ import (
 	"sort"
 
 	"github.com/Masterminds/semver"
+	"github.com/golang/dep/internal/gps/internal/pb"
 )
 
 var (
@@ -53,6 +54,10 @@ type Constraint interface {
 	// design goal of the system.
 	typedString() string
 
+	// copyTo copies fields into a serializable representation which can be
+	// converted back into an identical Constraint with constraintFromCache.
+	copyTo(*pb.Constraint)
+
 	// identical returns true if the constraints are identical.
 	//
 	// Identical Constraints behave identically for all methods defined by the
@@ -62,6 +67,46 @@ type Constraint interface {
 	identical(Constraint) bool
 }
 
+// constraintFromCache returns a Constraint identical to the one which produced m.
+func constraintFromCache(m *pb.Constraint) (Constraint, error) {
+	switch m.Type {
+	case pb.Constraint_Revision:
+		return Revision(m.Value), nil
+	case pb.Constraint_Branch:
+		return NewBranch(m.Value), nil
+	case pb.Constraint_DefaultBranch:
+		return newDefaultBranch(m.Value), nil
+	case pb.Constraint_Version:
+		return plainVersion(m.Value), nil
+	case pb.Constraint_Semver:
+		return NewSemverConstraint(m.Value)
+
+	default:
+		return nil, fmt.Errorf("unrecognized Constraint type: %#v", m)
+	}
+}
+
+// unpairedVersionFromCache returns an UnpairedVersion identical to the one which produced m.
+func unpairedVersionFromCache(m *pb.Constraint) (UnpairedVersion, error) {
+	switch m.Type {
+	case pb.Constraint_Branch:
+		return NewBranch(m.Value), nil
+	case pb.Constraint_DefaultBranch:
+		return newDefaultBranch(m.Value), nil
+	case pb.Constraint_Version:
+		return plainVersion(m.Value), nil
+	case pb.Constraint_Semver:
+		sv, err := semver.NewVersion(m.Value)
+		if err != nil {
+			return nil, err
+		}
+		return semVersion{sv: sv}, nil
+
+	default:
+		return nil, fmt.Errorf("unrecognized UnpairedVersion type: %#v", m)
+	}
+}
+
 // NewSemverConstraint attempts to construct a semver Constraint object from the
 // input string.
 //
@@ -188,6 +233,11 @@ func (c semverConstraint) identical(c2 Constraint) bool {
 	return c.c.String() == sc2.c.String()
 }
 
+func (c semverConstraint) copyTo(msg *pb.Constraint) {
+	msg.Type = pb.Constraint_Semver
+	msg.Value = c.String()
+}
+
 // IsAny indicates if the provided constraint is the wildcard "Any" constraint.
 func IsAny(c Constraint) bool {
 	_, ok := c.(anyConstraint)
@@ -231,6 +281,10 @@ func (anyConstraint) identical(c Constraint) bool {
 	return IsAny(c)
 }
 
+func (anyConstraint) copyTo(*pb.Constraint) {
+	panic("anyConstraint should never be serialized; it is solver internal-only")
+}
+
 // noneConstraint is the empty set - it matches no versions. It mirrors the
 // behavior of the semver package's none type.
 type noneConstraint struct{}
@@ -264,6 +318,10 @@ func (noneConstraint) identical(c Constraint) bool {
 	return ok
 }
 
+func (noneConstraint) copyTo(*pb.Constraint) {
+	panic("noneConstraint should never be serialized; it is solver internal-only")
+}
+
 // A ProjectConstraint combines a ProjectIdentifier with a Constraint. It
 // indicates that, if packages contained in the ProjectIdentifier enter the
 // depgraph, they must do so at a version that is allowed by the Constraint.

internal/gps/internal/pb/pb.go

@@ -0,0 +1,8 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package pb provides generated Protocol Buffers for cache serialization.
+package pb
+
+//go:generate protoc --go_out=. source_cache.proto