cfg/config.go - third_party/Masterminds/glide - Git at Google

 package cfg

 import (
 	"crypto/sha256"
 	"fmt"
 	"io/ioutil"
 	"reflect"
 	"strings"

 	"github.com/Masterminds/glide/util"
 	"github.com/Masterminds/vcs"
 	"gopkg.in/yaml.v2"
 )

 // Config is the top-level configuration object.
 type Config struct {

 	// Name is the name of the package or application.
 	Name string `yaml:"package"`

 	// Description is a short description for a package, application, or library.
 	// This description is similar but different to a Go package description as
 	// it is for marketing and presentation purposes rather than technical ones.
 	Description string `json:"description,omitempty"`

 	// Home is a url to a website for the package.
 	Home string `yaml:"homepage,omitempty"`

 	// License provides either a SPDX license or a path to a file containing
 	// the license. For more information on SPDX see http://spdx.org/licenses/.
 	// When more than one license an SPDX expression can be used.
 	License string `yaml:"license,omitempty"`

 	// Owners is an array of owners for a project. See the Owner type for
 	// more detail. These can be one or more people, companies, or other
 	// organizations.
 	Owners Owners `yaml:"owners,omitempty"`

 	// Ignore contains a list of packages to ignore fetching. This is useful
 	// when walking the package tree (including packages of packages) to list
 	// those to skip.
 	Ignore []string `yaml:"ignore,omitempty"`

 	// Exclude contains a list of directories in the local application to
 	// exclude from scanning for dependencies.
 	Exclude []string `yaml:"excludeDirs,omitempty"`

 	// Imports contains a list of all non-development imports for a project. For
 	// more detail on how these are captured see the Dependency type.
 	Imports Dependencies `yaml:"import"`

 	// DevImports contains the test or other development imports for a project.
 	// See the Dependency type for more details on how this is recorded.
 	DevImports Dependencies `yaml:"testImport,omitempty"`
 }

 // A transitive representation of a dependency for importing and exporting to yaml.
 type cf struct {
 	Name        string       `yaml:"package"`
 	Description string       `yaml:"description,omitempty"`
 	Home        string       `yaml:"homepage,omitempty"`
 	License     string       `yaml:"license,omitempty"`
 	Owners      Owners       `yaml:"owners,omitempty"`
 	Ignore      []string     `yaml:"ignore,omitempty"`
 	Exclude     []string     `yaml:"excludeDirs,omitempty"`
 	Imports     Dependencies `yaml:"import"`
 	DevImports  Dependencies `yaml:"testImport,omitempty"`
 }

 // ConfigFromYaml returns an instance of Config from YAML
 func ConfigFromYaml(yml []byte) (*Config, error) {
 	cfg := &Config{}
 	err := yaml.Unmarshal([]byte(yml), &cfg)
 	return cfg, err
 }

 // Marshal converts a Config instance to YAML
 func (c *Config) Marshal() ([]byte, error) {
 	yml, err := yaml.Marshal(&c)
 	if err != nil {
 		return []byte{}, err
 	}
 	return yml, nil
 }

 // UnmarshalYAML is a hook for gopkg.in/yaml.v2 in the unmarshalling process
 func (c *Config) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	newConfig := &cf{}
 	if err := unmarshal(&newConfig); err != nil {
 		return err
 	}
 	c.Name = newConfig.Name
 	c.Description = newConfig.Description
 	c.Home = newConfig.Home
 	c.License = newConfig.License
 	c.Owners = newConfig.Owners
 	c.Ignore = newConfig.Ignore
 	c.Exclude = newConfig.Exclude
 	c.Imports = newConfig.Imports
 	c.DevImports = newConfig.DevImports

 	// Cleanup the Config object now that we have it.
 	err := c.DeDupe()

 	return err
 }

 // MarshalYAML is a hook for gopkg.in/yaml.v2 in the marshaling process
 func (c *Config) MarshalYAML() (interface{}, error) {
 	newConfig := &cf{
 		Name:        c.Name,
 		Description: c.Description,
 		Home:        c.Home,
 		License:     c.License,
 		Owners:      c.Owners,
 		Ignore:      c.Ignore,
 		Exclude:     c.Exclude,
 	}
 	i, err := c.Imports.Clone().DeDupe()
 	if err != nil {
 		return newConfig, err
 	}

 	di, err := c.DevImports.Clone().DeDupe()
 	if err != nil {
 		return newConfig, err
 	}

 	newConfig.Imports = i
 	newConfig.DevImports = di

 	return newConfig, nil
 }

 // HasDependency returns true if the given name is listed as an import or dev import.
 func (c *Config) HasDependency(name string) bool {
 	for _, d := range c.Imports {
 		if d.Name == name {
 			return true
 		}
 	}
 	for _, d := range c.DevImports {
 		if d.Name == name {
 			return true
 		}
 	}
 	return false
 }

 // HasIgnore returns true if the given name is listed on the ignore list.
 func (c *Config) HasIgnore(name string) bool {
 	for _, v := range c.Ignore {

 		// Check for both a name and to make sure sub-packages are ignored as
 		// well.
 		if v == name || strings.HasPrefix(name, v+"/") {
 			return true
 		}
 	}

 	return false
 }

 // HasExclude returns true if the given name is listed on the exclude list.
 func (c *Config) HasExclude(ex string) bool {
 	ep := normalizeSlash(ex)
 	for _, v := range c.Exclude {
 		if vp := normalizeSlash(v); vp == ep {
 			return true
 		}
 	}

 	return false
 }

 // Clone performs a deep clone of the Config instance
 func (c *Config) Clone() *Config {
 	n := &Config{}
 	n.Name = c.Name
 	n.Description = c.Description
 	n.Home = c.Home
 	n.License = c.License
 	n.Owners = c.Owners.Clone()
 	n.Ignore = c.Ignore
 	n.Exclude = c.Exclude
 	n.Imports = c.Imports.Clone()
 	n.DevImports = c.DevImports.Clone()
 	return n
 }

 // WriteFile writes a Glide YAML file.
 //
 // This is a convenience function that marshals the YAML and then writes it to
 // the given file. If the file exists, it will be clobbered.
 func (c *Config) WriteFile(glidepath string) error {
 	o, err := c.Marshal()
 	if err != nil {
 		return err
 	}
 	return ioutil.WriteFile(glidepath, o, 0666)
 }

 // DeDupe consolidates duplicate dependencies on a Config instance
 func (c *Config) DeDupe() error {

 	// Remove duplicates in the imports
 	var err error
 	c.Imports, err = c.Imports.DeDupe()
 	if err != nil {
 		return err
 	}
 	c.DevImports, err = c.DevImports.DeDupe()
 	if err != nil {
 		return err
 	}

 	// If the name on the config object is part of the imports remove it.
 	found := -1
 	for i, dep := range c.Imports {
 		if dep.Name == c.Name {
 			found = i
 		}
 	}
 	if found >= 0 {
 		c.Imports = append(c.Imports[:found], c.Imports[found+1:]...)
 	}

 	found = -1
 	for i, dep := range c.DevImports {
 		if dep.Name == c.Name {
 			found = i
 		}
 	}
 	if found >= 0 {
 		c.DevImports = append(c.DevImports[:found], c.DevImports[found+1:]...)
 	}

 	// If something is on the ignore list remove it from the imports.
 	for _, v := range c.Ignore {
 		found = -1
 		for k, d := range c.Imports {
 			if v == d.Name {
 				found = k
 			}
 		}
 		if found >= 0 {
 			c.Imports = append(c.Imports[:found], c.Imports[found+1:]...)
 		}

 		found = -1
 		for k, d := range c.DevImports {
 			if v == d.Name {
 				found = k
 			}
 		}
 		if found >= 0 {
 			c.DevImports = append(c.DevImports[:found], c.DevImports[found+1:]...)
 		}
 	}

 	return nil
 }

 // AddImport appends dependencies to the import list, deduplicating as we go.
 func (c *Config) AddImport(deps ...*Dependency) error {
 	t := c.Imports
 	t = append(t, deps...)
 	t, err := t.DeDupe()
 	if err != nil {
 		return err
 	}
 	c.Imports = t
 	return nil
 }

 // Hash generates a sha256 hash for a given Config
 func (c *Config) Hash() (string, error) {
 	yml, err := c.Marshal()
 	if err != nil {
 		return "", err
 	}

 	hash := sha256.New()
 	hash.Write(yml)
 	return fmt.Sprintf("%x", hash.Sum(nil)), nil
 }

 // Dependencies is a collection of Dependency
 type Dependencies []*Dependency

 // Get a dependency by name
 func (d Dependencies) Get(name string) *Dependency {
 	for _, dep := range d {
 		if dep.Name == name {
 			return dep
 		}
 	}
 	return nil
 }

 // Has checks if a dependency is on a list of dependencies such as import or testImport
 func (d Dependencies) Has(name string) bool {
 	for _, dep := range d {
 		if dep.Name == name {
 			return true
 		}
 	}
 	return false
 }

 // Remove removes a dependency from a list of dependencies
 func (d Dependencies) Remove(name string) Dependencies {
 	found := -1
 	for i, dep := range d {
 		if dep.Name == name {
 			found = i
 		}
 	}

 	if found >= 0 {
 		copy(d[found:], d[found+1:])
 		d[len(d)-1] = nil
 		return d[:len(d)-1]
 	}
 	return d
 }

 // Clone performs a deep clone of Dependencies
 func (d Dependencies) Clone() Dependencies {
 	n := make(Dependencies, 0, len(d))
 	for _, v := range d {
 		n = append(n, v.Clone())
 	}
 	return n
 }

 // DeDupe cleans up duplicates on a list of dependencies.
 func (d Dependencies) DeDupe() (Dependencies, error) {
 	checked := map[string]int{}
 	imports := make(Dependencies, 0, 1)
 	i := 0
 	for _, dep := range d {
 		// The first time we encounter a dependency add it to the list
 		if val, ok := checked[dep.Name]; !ok {
 			checked[dep.Name] = i
 			imports = append(imports, dep)
 			i++
 		} else {
 			// In here we've encountered a dependency for the second time.
 			// Make sure the details are the same or return an error.
 			v := imports[val]
 			if dep.Reference != v.Reference {
 				return d, fmt.Errorf("Import %s repeated with different versions '%s' and '%s'", dep.Name, dep.Reference, v.Reference)
 			}
 			if dep.Repository != v.Repository || dep.VcsType != v.VcsType {
 				return d, fmt.Errorf("Import %s repeated with different Repository details", dep.Name)
 			}
 			if !reflect.DeepEqual(dep.Os, v.Os) || !reflect.DeepEqual(dep.Arch, v.Arch) {
 				return d, fmt.Errorf("Import %s repeated with different OS or Architecture filtering", dep.Name)
 			}
 			imports[checked[dep.Name]].Subpackages = stringArrayDeDupe(v.Subpackages, dep.Subpackages...)
 		}
 	}

 	return imports, nil
 }

 // Dependency describes a package that the present package depends upon.
 type Dependency struct {
 	Name             string   `yaml:"package"`
 	Reference        string   `yaml:"version,omitempty"`
 	Pin              string   `yaml:"-"`
 	Repository       string   `yaml:"repo,omitempty"`
 	VcsType          string   `yaml:"vcs,omitempty"`
 	Subpackages      []string `yaml:"subpackages,omitempty"`
 	Arch             []string `yaml:"arch,omitempty"`
 	Os               []string `yaml:"os,omitempty"`
 	UpdateAsVendored bool     `yaml:"-"`
 }

 // A transitive representation of a dependency for importing and exploting to yaml.
 type dep struct {
 	Name        string   `yaml:"package"`
 	Reference   string   `yaml:"version,omitempty"`
 	Ref         string   `yaml:"ref,omitempty"`
 	Repository  string   `yaml:"repo,omitempty"`
 	VcsType     string   `yaml:"vcs,omitempty"`
 	Subpackages []string `yaml:"subpackages,omitempty"`
 	Arch        []string `yaml:"arch,omitempty"`
 	Os          []string `yaml:"os,omitempty"`
 }

 // DependencyFromLock converts a Lock to a Dependency
 func DependencyFromLock(lock *Lock) *Dependency {
 	return &Dependency{
 		Name:        lock.Name,
 		Reference:   lock.Version,
 		Repository:  lock.Repository,
 		VcsType:     lock.VcsType,
 		Subpackages: lock.Subpackages,
 		Arch:        lock.Arch,
 		Os:          lock.Os,
 	}
 }

 // UnmarshalYAML is a hook for gopkg.in/yaml.v2 in the unmarshaling process
 func (d *Dependency) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	newDep := &dep{}
 	err := unmarshal(&newDep)
 	if err != nil {
 		return err
 	}
 	d.Name = newDep.Name
 	d.Reference = newDep.Reference
 	d.Repository = newDep.Repository
 	d.VcsType = newDep.VcsType
 	d.Subpackages = newDep.Subpackages
 	d.Arch = newDep.Arch
 	d.Os = newDep.Os

 	if d.Reference == "" && newDep.Ref != "" {
 		d.Reference = newDep.Ref
 	}

 	// Make sure only legitimate VCS are listed.
 	d.VcsType = filterVcsType(d.VcsType)

 	// Get the root name for the package
 	tn, subpkg := util.NormalizeName(d.Name)
 	d.Name = tn
 	if subpkg != "" {
 		d.Subpackages = append(d.Subpackages, subpkg)
 	}

 	// Older versions of Glide had a / prefix on subpackages in some cases.
 	// Here that's cleaned up. Someday we should be able to remove this.
 	for k, v := range d.Subpackages {
 		d.Subpackages[k] = strings.TrimPrefix(v, "/")
 	}

 	return nil
 }

 // MarshalYAML is a hook for gopkg.in/yaml.v2 in the marshaling process
 func (d *Dependency) MarshalYAML() (interface{}, error) {

 	// Make sure we only write the correct vcs type to file
 	t := filterVcsType(d.VcsType)
 	newDep := &dep{
 		Name:        d.Name,
 		Reference:   d.Reference,
 		Repository:  d.Repository,
 		VcsType:     t,
 		Subpackages: d.Subpackages,
 		Arch:        d.Arch,
 		Os:          d.Os,
 	}

 	return newDep, nil
 }

 // GetRepo retrieves a Masterminds/vcs repo object configured for the root
 // of the package being retrieved.
 func (d *Dependency) GetRepo(dest string) (vcs.Repo, error) {

 	// The remote location is either the configured repo or the package
 	// name as an https url.
 	var remote string
 	if len(d.Repository) > 0 {
 		remote = d.Repository
 	} else {
 		remote = "https://" + d.Name
 	}

 	// If the VCS type has a value we try that first.
 	if len(d.VcsType) > 0 && d.VcsType != "None" {
 		switch vcs.Type(d.VcsType) {
 		case vcs.Git:
 			return vcs.NewGitRepo(remote, dest)
 		case vcs.Svn:
 			return vcs.NewSvnRepo(remote, dest)
 		case vcs.Hg:
 			return vcs.NewHgRepo(remote, dest)
 		case vcs.Bzr:
 			return vcs.NewBzrRepo(remote, dest)
 		default:
 			return nil, fmt.Errorf("Unknown VCS type %s set for %s", d.VcsType, d.Name)
 		}
 	}

 	// When no type set we try to autodetect.
 	return vcs.NewRepo(remote, dest)
 }

 // Clone creates a clone of a Dependency
 func (d *Dependency) Clone() *Dependency {
 	return &Dependency{
 		Name:             d.Name,
 		Reference:        d.Reference,
 		Pin:              d.Pin,
 		Repository:       d.Repository,
 		VcsType:          d.VcsType,
 		Subpackages:      d.Subpackages,
 		Arch:             d.Arch,
 		Os:               d.Os,
 		UpdateAsVendored: d.UpdateAsVendored,
 	}
 }

 // HasSubpackage returns if the subpackage is present on the dependency
 func (d *Dependency) HasSubpackage(sub string) bool {

 	for _, v := range d.Subpackages {
 		if sub == v {
 			return true
 		}
 	}

 	return false
 }

 // Owners is a list of owners for a project.
 type Owners []*Owner

 // Clone performs a deep clone of Owners
 func (o Owners) Clone() Owners {
 	n := make(Owners, 0, 1)
 	for _, v := range o {
 		n = append(n, v.Clone())
 	}
 	return n
 }

 // Owner describes an owner of a package. This can be a person, company, or
 // other organization. This is useful if someone needs to contact the
 // owner of a package to address things like a security issue.
 type Owner struct {

 	// Name describes the name of an organization.
 	Name string `yaml:"name,omitempty"`

 	// Email is an email address to reach the owner at.
 	Email string `yaml:"email,omitempty"`

 	// Home is a url to a website for the owner.
 	Home string `yaml:"homepage,omitempty"`
 }

 // Clone creates a clone of a Dependency
 func (o *Owner) Clone() *Owner {
 	return &Owner{
 		Name:  o.Name,
 		Email: o.Email,
 		Home:  o.Home,
 	}
 }

 func stringArrayDeDupe(s []string, items ...string) []string {
 	for _, item := range items {
 		exists := false
 		for _, v := range s {
 			if v == item {
 				exists = true
 			}
 		}
 		if !exists {
 			s = append(s, item)
 		}
 	}
 	return s
 }

 func filterVcsType(vcs string) string {
 	switch vcs {
 	case "git", "hg", "bzr", "svn":
 		return vcs
 	case "mercurial":
 		return "hg"
 	case "bazaar":
 		return "bzr"
 	case "subversion":
 		return "svn"
 	default:
 		return ""
 	}
 }

 func normalizeSlash(k string) string {
 	return strings.Replace(k, "\\", "/", -1)
 }
	package cfg

	import (
	"crypto/sha256"
	"fmt"
	"io/ioutil"
	"reflect"
	"strings"

	"github.com/Masterminds/glide/util"
	"github.com/Masterminds/vcs"
	"gopkg.in/yaml.v2"
	)

	// Config is the top-level configuration object.
	type Config struct {

	// Name is the name of the package or application.
	Name string `yaml:"package"`

	// Description is a short description for a package, application, or library.
	// This description is similar but different to a Go package description as
	// it is for marketing and presentation purposes rather than technical ones.
	Description string `json:"description,omitempty"`

	// Home is a url to a website for the package.
	Home string `yaml:"homepage,omitempty"`

	// License provides either a SPDX license or a path to a file containing
	// the license. For more information on SPDX see http://spdx.org/licenses/.
	// When more than one license an SPDX expression can be used.
	License string `yaml:"license,omitempty"`

	// Owners is an array of owners for a project. See the Owner type for
	// more detail. These can be one or more people, companies, or other
	// organizations.
	Owners Owners `yaml:"owners,omitempty"`

	// Ignore contains a list of packages to ignore fetching. This is useful
	// when walking the package tree (including packages of packages) to list
	// those to skip.
	Ignore []string `yaml:"ignore,omitempty"`

	// Exclude contains a list of directories in the local application to
	// exclude from scanning for dependencies.
	Exclude []string `yaml:"excludeDirs,omitempty"`

	// Imports contains a list of all non-development imports for a project. For
	// more detail on how these are captured see the Dependency type.
	Imports Dependencies `yaml:"import"`

	// DevImports contains the test or other development imports for a project.
	// See the Dependency type for more details on how this is recorded.
	DevImports Dependencies `yaml:"testImport,omitempty"`
	}

	// A transitive representation of a dependency for importing and exporting to yaml.
	type cf struct {
	Name string `yaml:"package"`
	Description string `yaml:"description,omitempty"`
	Home string `yaml:"homepage,omitempty"`
	License string `yaml:"license,omitempty"`
	Owners Owners `yaml:"owners,omitempty"`
	Ignore []string `yaml:"ignore,omitempty"`
	Exclude []string `yaml:"excludeDirs,omitempty"`
	Imports Dependencies `yaml:"import"`
	DevImports Dependencies `yaml:"testImport,omitempty"`
	}

	// ConfigFromYaml returns an instance of Config from YAML
	func ConfigFromYaml(yml []byte) (*Config, error) {
	cfg := &Config{}
	err := yaml.Unmarshal([]byte(yml), &cfg)
	return cfg, err
	}

	// Marshal converts a Config instance to YAML
	func (c *Config) Marshal() ([]byte, error) {
	yml, err := yaml.Marshal(&c)
	if err != nil {
	return []byte{}, err
	}
	return yml, nil
	}

	// UnmarshalYAML is a hook for gopkg.in/yaml.v2 in the unmarshalling process
	func (c *Config) UnmarshalYAML(unmarshal func(interface{}) error) error {
	newConfig := &cf{}
	if err := unmarshal(&newConfig); err != nil {
	return err
	}
	c.Name = newConfig.Name
	c.Description = newConfig.Description
	c.Home = newConfig.Home
	c.License = newConfig.License
	c.Owners = newConfig.Owners
	c.Ignore = newConfig.Ignore
	c.Exclude = newConfig.Exclude
	c.Imports = newConfig.Imports
	c.DevImports = newConfig.DevImports

	// Cleanup the Config object now that we have it.
	err := c.DeDupe()

	return err
	}

	// MarshalYAML is a hook for gopkg.in/yaml.v2 in the marshaling process
	func (c *Config) MarshalYAML() (interface{}, error) {
	newConfig := &cf{
	Name: c.Name,
	Description: c.Description,
	Home: c.Home,
	License: c.License,
	Owners: c.Owners,
	Ignore: c.Ignore,
	Exclude: c.Exclude,
	}
	i, err := c.Imports.Clone().DeDupe()
	if err != nil {
	return newConfig, err
	}

	di, err := c.DevImports.Clone().DeDupe()
	if err != nil {
	return newConfig, err
	}

	newConfig.Imports = i
	newConfig.DevImports = di

	return newConfig, nil
	}

	// HasDependency returns true if the given name is listed as an import or dev import.
	func (c *Config) HasDependency(name string) bool {
	for _, d := range c.Imports {
	if d.Name == name {
	return true
	}
	}
	for _, d := range c.DevImports {
	if d.Name == name {
	return true
	}
	}
	return false
	}

	// HasIgnore returns true if the given name is listed on the ignore list.
	func (c *Config) HasIgnore(name string) bool {
	for _, v := range c.Ignore {

	// Check for both a name and to make sure sub-packages are ignored as
	// well.
	if v == name \|\| strings.HasPrefix(name, v+"/") {
	return true
	}
	}

	return false
	}

	// HasExclude returns true if the given name is listed on the exclude list.
	func (c *Config) HasExclude(ex string) bool {
	ep := normalizeSlash(ex)
	for _, v := range c.Exclude {
	if vp := normalizeSlash(v); vp == ep {
	return true
	}
	}

	return false
	}

	// Clone performs a deep clone of the Config instance
	func (c Config) Clone() Config {
	n := &Config{}
	n.Name = c.Name
	n.Description = c.Description
	n.Home = c.Home
	n.License = c.License
	n.Owners = c.Owners.Clone()
	n.Ignore = c.Ignore
	n.Exclude = c.Exclude
	n.Imports = c.Imports.Clone()
	n.DevImports = c.DevImports.Clone()
	return n
	}

	// WriteFile writes a Glide YAML file.
	//
	// This is a convenience function that marshals the YAML and then writes it to
	// the given file. If the file exists, it will be clobbered.
	func (c *Config) WriteFile(glidepath string) error {
	o, err := c.Marshal()
	if err != nil {
	return err
	}
	return ioutil.WriteFile(glidepath, o, 0666)
	}

	// DeDupe consolidates duplicate dependencies on a Config instance
	func (c *Config) DeDupe() error {

	// Remove duplicates in the imports
	var err error
	c.Imports, err = c.Imports.DeDupe()
	if err != nil {
	return err
	}
	c.DevImports, err = c.DevImports.DeDupe()
	if err != nil {
	return err
	}

	// If the name on the config object is part of the imports remove it.
	found := -1
	for i, dep := range c.Imports {
	if dep.Name == c.Name {
	found = i
	}
	}
	if found >= 0 {
	c.Imports = append(c.Imports[:found], c.Imports[found+1:]...)
	}

	found = -1
	for i, dep := range c.DevImports {
	if dep.Name == c.Name {
	found = i
	}
	}
	if found >= 0 {
	c.DevImports = append(c.DevImports[:found], c.DevImports[found+1:]...)
	}

	// If something is on the ignore list remove it from the imports.
	for _, v := range c.Ignore {
	found = -1
	for k, d := range c.Imports {
	if v == d.Name {
	found = k
	}
	}
	if found >= 0 {
	c.Imports = append(c.Imports[:found], c.Imports[found+1:]...)
	}

	found = -1
	for k, d := range c.DevImports {
	if v == d.Name {
	found = k
	}
	}
	if found >= 0 {
	c.DevImports = append(c.DevImports[:found], c.DevImports[found+1:]...)
	}
	}

	return nil
	}

	// AddImport appends dependencies to the import list, deduplicating as we go.
	func (c Config) AddImport(deps ...Dependency) error {
	t := c.Imports
	t = append(t, deps...)
	t, err := t.DeDupe()
	if err != nil {
	return err
	}
	c.Imports = t
	return nil
	}

	// Hash generates a sha256 hash for a given Config
	func (c *Config) Hash() (string, error) {
	yml, err := c.Marshal()
	if err != nil {
	return "", err
	}

	hash := sha256.New()
	hash.Write(yml)
	return fmt.Sprintf("%x", hash.Sum(nil)), nil
	}

	// Dependencies is a collection of Dependency
	type Dependencies []*Dependency

	// Get a dependency by name
	func (d Dependencies) Get(name string) *Dependency {
	for _, dep := range d {
	if dep.Name == name {
	return dep
	}
	}
	return nil
	}

	// Has checks if a dependency is on a list of dependencies such as import or testImport
	func (d Dependencies) Has(name string) bool {
	for _, dep := range d {
	if dep.Name == name {
	return true
	}
	}
	return false
	}

	// Remove removes a dependency from a list of dependencies
	func (d Dependencies) Remove(name string) Dependencies {
	found := -1
	for i, dep := range d {
	if dep.Name == name {
	found = i
	}
	}

	if found >= 0 {
	copy(d[found:], d[found+1:])
	d[len(d)-1] = nil
	return d[:len(d)-1]
	}
	return d
	}

	// Clone performs a deep clone of Dependencies
	func (d Dependencies) Clone() Dependencies {
	n := make(Dependencies, 0, len(d))
	for _, v := range d {
	n = append(n, v.Clone())
	}
	return n
	}

	// DeDupe cleans up duplicates on a list of dependencies.
	func (d Dependencies) DeDupe() (Dependencies, error) {
	checked := map[string]int{}
	imports := make(Dependencies, 0, 1)
	i := 0
	for _, dep := range d {
	// The first time we encounter a dependency add it to the list
	if val, ok := checked[dep.Name]; !ok {
	checked[dep.Name] = i
	imports = append(imports, dep)
	i++
	} else {
	// In here we've encountered a dependency for the second time.
	// Make sure the details are the same or return an error.
	v := imports[val]
	if dep.Reference != v.Reference {
	return d, fmt.Errorf("Import %s repeated with different versions '%s' and '%s'", dep.Name, dep.Reference, v.Reference)
	}
	if dep.Repository != v.Repository \|\| dep.VcsType != v.VcsType {
	return d, fmt.Errorf("Import %s repeated with different Repository details", dep.Name)
	}
	if !reflect.DeepEqual(dep.Os, v.Os) \|\| !reflect.DeepEqual(dep.Arch, v.Arch) {
	return d, fmt.Errorf("Import %s repeated with different OS or Architecture filtering", dep.Name)
	}
	imports[checked[dep.Name]].Subpackages = stringArrayDeDupe(v.Subpackages, dep.Subpackages...)
	}
	}

	return imports, nil
	}

	// Dependency describes a package that the present package depends upon.
	type Dependency struct {
	Name string `yaml:"package"`
	Reference string `yaml:"version,omitempty"`
	Pin string `yaml:"-"`
	Repository string `yaml:"repo,omitempty"`
	VcsType string `yaml:"vcs,omitempty"`
	Subpackages []string `yaml:"subpackages,omitempty"`
	Arch []string `yaml:"arch,omitempty"`
	Os []string `yaml:"os,omitempty"`
	UpdateAsVendored bool `yaml:"-"`
	}

	// A transitive representation of a dependency for importing and exploting to yaml.
	type dep struct {
	Name string `yaml:"package"`
	Reference string `yaml:"version,omitempty"`
	Ref string `yaml:"ref,omitempty"`
	Repository string `yaml:"repo,omitempty"`
	VcsType string `yaml:"vcs,omitempty"`
	Subpackages []string `yaml:"subpackages,omitempty"`
	Arch []string `yaml:"arch,omitempty"`
	Os []string `yaml:"os,omitempty"`
	}

	// DependencyFromLock converts a Lock to a Dependency
	func DependencyFromLock(lock Lock) Dependency {
	return &Dependency{
	Name: lock.Name,
	Reference: lock.Version,
	Repository: lock.Repository,
	VcsType: lock.VcsType,
	Subpackages: lock.Subpackages,
	Arch: lock.Arch,
	Os: lock.Os,
	}
	}

	// UnmarshalYAML is a hook for gopkg.in/yaml.v2 in the unmarshaling process
	func (d *Dependency) UnmarshalYAML(unmarshal func(interface{}) error) error {
	newDep := &dep{}
	err := unmarshal(&newDep)
	if err != nil {
	return err
	}
	d.Name = newDep.Name
	d.Reference = newDep.Reference
	d.Repository = newDep.Repository
	d.VcsType = newDep.VcsType
	d.Subpackages = newDep.Subpackages
	d.Arch = newDep.Arch
	d.Os = newDep.Os

	if d.Reference == "" && newDep.Ref != "" {
	d.Reference = newDep.Ref
	}

	// Make sure only legitimate VCS are listed.
	d.VcsType = filterVcsType(d.VcsType)

	// Get the root name for the package
	tn, subpkg := util.NormalizeName(d.Name)
	d.Name = tn
	if subpkg != "" {
	d.Subpackages = append(d.Subpackages, subpkg)
	}

	// Older versions of Glide had a / prefix on subpackages in some cases.
	// Here that's cleaned up. Someday we should be able to remove this.
	for k, v := range d.Subpackages {
	d.Subpackages[k] = strings.TrimPrefix(v, "/")
	}

	return nil
	}

	// MarshalYAML is a hook for gopkg.in/yaml.v2 in the marshaling process
	func (d *Dependency) MarshalYAML() (interface{}, error) {

	// Make sure we only write the correct vcs type to file
	t := filterVcsType(d.VcsType)
	newDep := &dep{
	Name: d.Name,
	Reference: d.Reference,
	Repository: d.Repository,
	VcsType: t,
	Subpackages: d.Subpackages,
	Arch: d.Arch,
	Os: d.Os,
	}

	return newDep, nil
	}

	// GetRepo retrieves a Masterminds/vcs repo object configured for the root
	// of the package being retrieved.
	func (d *Dependency) GetRepo(dest string) (vcs.Repo, error) {

	// The remote location is either the configured repo or the package
	// name as an https url.
	var remote string
	if len(d.Repository) > 0 {
	remote = d.Repository
	} else {
	remote = "https://" + d.Name
	}

	// If the VCS type has a value we try that first.
	if len(d.VcsType) > 0 && d.VcsType != "None" {
	switch vcs.Type(d.VcsType) {
	case vcs.Git:
	return vcs.NewGitRepo(remote, dest)
	case vcs.Svn:
	return vcs.NewSvnRepo(remote, dest)
	case vcs.Hg:
	return vcs.NewHgRepo(remote, dest)
	case vcs.Bzr:
	return vcs.NewBzrRepo(remote, dest)
	default:
	return nil, fmt.Errorf("Unknown VCS type %s set for %s", d.VcsType, d.Name)
	}
	}

	// When no type set we try to autodetect.
	return vcs.NewRepo(remote, dest)
	}

	// Clone creates a clone of a Dependency
	func (d Dependency) Clone() Dependency {
	return &Dependency{
	Name: d.Name,
	Reference: d.Reference,
	Pin: d.Pin,
	Repository: d.Repository,
	VcsType: d.VcsType,
	Subpackages: d.Subpackages,
	Arch: d.Arch,
	Os: d.Os,
	UpdateAsVendored: d.UpdateAsVendored,
	}
	}

	// HasSubpackage returns if the subpackage is present on the dependency
	func (d *Dependency) HasSubpackage(sub string) bool {

	for _, v := range d.Subpackages {
	if sub == v {
	return true
	}
	}

	return false
	}

	// Owners is a list of owners for a project.
	type Owners []*Owner

	// Clone performs a deep clone of Owners
	func (o Owners) Clone() Owners {
	n := make(Owners, 0, 1)
	for _, v := range o {
	n = append(n, v.Clone())
	}
	return n
	}

	// Owner describes an owner of a package. This can be a person, company, or
	// other organization. This is useful if someone needs to contact the
	// owner of a package to address things like a security issue.
	type Owner struct {

	// Name describes the name of an organization.
	Name string `yaml:"name,omitempty"`

	// Email is an email address to reach the owner at.
	Email string `yaml:"email,omitempty"`

	// Home is a url to a website for the owner.
	Home string `yaml:"homepage,omitempty"`
	}

	// Clone creates a clone of a Dependency
	func (o Owner) Clone() Owner {
	return &Owner{
	Name: o.Name,
	Email: o.Email,
	Home: o.Home,
	}
	}

	func stringArrayDeDupe(s []string, items ...string) []string {
	for _, item := range items {
	exists := false
	for _, v := range s {
	if v == item {
	exists = true
	}
	}
	if !exists {
	s = append(s, item)
	}
	}
	return s
	}

	func filterVcsType(vcs string) string {
	switch vcs {
	case "git", "hg", "bzr", "svn":
	return vcs
	case "mercurial":
	return "hg"
	case "bazaar":
	return "bzr"
	case "subversion":
	return "svn"
	default:
	return ""
	}
	}

	func normalizeSlash(k string) string {
	return strings.Replace(k, "\\", "/", -1)
	}