GOMODULES
/
go-exif
mirror of https://github.com/dsoprea/go-exif.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

ifd.go: Add missing comments

dustin/master
Dustin Oprea 2020-05-20 04:48:42 -04:00
parent 04a4b5ce62
commit 40de7cc624
1 changed files with 16 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
v2/ifd.go
View File

@ -18,6 +18,7 @@ var (
ErrChildIfdNotMapped = errors.New("no child-IFD for that tag-ID under parent") ErrChildIfdNotMapped = errors.New("no child-IFD for that tag-ID under parent")
) )
// MappedIfd is one node in the IFD-mapping.
type MappedIfd struct { type MappedIfd struct {
ParentTagId uint16 ParentTagId uint16
Placement []uint16 Placement []uint16
@ -28,20 +29,25 @@ type MappedIfd struct {
Children map[uint16]*MappedIfd Children map[uint16]*MappedIfd
} }
// String returns a descriptive string.
func (mi *MappedIfd) String() string { func (mi *MappedIfd) String() string {
pathPhrase := mi.PathPhrase() pathPhrase := mi.PathPhrase()
return fmt.Sprintf("MappedIfd<(0x%04X) [%s] PATH=[%s]>", mi.TagId, mi.Name, pathPhrase) return fmt.Sprintf("MappedIfd<(0x%04X) [%s] PATH=[%s]>", mi.TagId, mi.Name, pathPhrase)
} }
// PathPhrase returns a non-fully-qualified IFD path.
func (mi *MappedIfd) PathPhrase() string { func (mi *MappedIfd) PathPhrase() string {
return strings.Join(mi.Path, "/") return strings.Join(mi.Path, "/")
} }
// TODO(dustin): Refactor this to use IfdIdentity structs.
// IfdMapping describes all of the IFDs that we currently recognize. // IfdMapping describes all of the IFDs that we currently recognize.
type IfdMapping struct { type IfdMapping struct {
rootNode *MappedIfd rootNode *MappedIfd
} }
// NewIfdMapping returns a new IfdMapping struct.
func NewIfdMapping() (ifdMapping *IfdMapping) { func NewIfdMapping() (ifdMapping *IfdMapping) {
rootNode := &MappedIfd{ rootNode := &MappedIfd{
Path: make([]string, 0), Path: make([]string, 0),
@ -53,6 +59,8 @@ func NewIfdMapping() (ifdMapping *IfdMapping) {
} }
} }
// NewIfdMappingWithStandard retruns a new IfdMapping struct preloaded with the
// standard IFDs.
func NewIfdMappingWithStandard() (ifdMapping *IfdMapping) { func NewIfdMappingWithStandard() (ifdMapping *IfdMapping) {
defer func() { defer func() {
if state := recover(); state != nil { if state := recover(); state != nil {
@ -69,6 +77,7 @@ func NewIfdMappingWithStandard() (ifdMapping *IfdMapping) {
return im return im
} }
// Get returns the node given the path slice.
func (im *IfdMapping) Get(parentPlacement []uint16) (childIfd *MappedIfd, err error) { func (im *IfdMapping) Get(parentPlacement []uint16) (childIfd *MappedIfd, err error) {
defer func() { defer func() {
if state := recover(); state != nil { if state := recover(); state != nil {
@ -88,6 +97,7 @@ func (im *IfdMapping) Get(parentPlacement []uint16) (childIfd *MappedIfd, err er
return ptr, nil return ptr, nil
} }
// GetWithPath returns the node given the path string.
func (im *IfdMapping) GetWithPath(pathPhrase string) (mi *MappedIfd, err error) { func (im *IfdMapping) GetWithPath(pathPhrase string) (mi *MappedIfd, err error) {
defer func() { defer func() {
if state := recover(); state != nil { if state := recover(); state != nil {
@ -145,12 +155,16 @@ func (im *IfdMapping) GetChild(parentPathPhrase string, tagId uint16) (mi *Mappe
return nil, nil return nil, nil
} }
// IfdTagIdAndIndex represents a specific part of the IFD path.
//
// This is a legacy type.
type IfdTagIdAndIndex struct { type IfdTagIdAndIndex struct {
Name string Name string
TagId uint16 TagId uint16
Index int Index int
} }
// String returns a descriptive string.
func (itii IfdTagIdAndIndex) String() string { func (itii IfdTagIdAndIndex) String() string {
return fmt.Sprintf("IfdTagIdAndIndex<NAME=[%s] ID=(%04x) INDEX=(%d)>", itii.Name, itii.TagId, itii.Index) return fmt.Sprintf("IfdTagIdAndIndex<NAME=[%s] ID=(%04x) INDEX=(%d)>", itii.Name, itii.TagId, itii.Index)
} }
@ -336,6 +350,7 @@ func (im *IfdMapping) dumpLineages(stack []*MappedIfd, input []string) (output [
return output, nil return output, nil
} }
// DumpLineages returns a slice of strings representing all mappings.
func (im *IfdMapping) DumpLineages() (output []string, err error) { func (im *IfdMapping) DumpLineages() (output []string, err error) {
defer func() { defer func() {
if state := recover(); state != nil { if state := recover(); state != nil {
@ -352,6 +367,7 @@ func (im *IfdMapping) DumpLineages() (output []string, err error) {
return output, nil return output, nil
} }
// LoadStandardIfds loads the standard IFDs into the mapping.
func LoadStandardIfds(im *IfdMapping) (err error) { func LoadStandardIfds(im *IfdMapping) (err error) {
defer func() { defer func() {
if state := recover(); state != nil { if state := recover(); state != nil {