sec/compose_tree.go

92 lines
2.7 KiB
Go

package sec
import (
// stdlib
"reflect"
"strings"
)
// Composes full tree for every structure member.
func composeTree(value reflect.Value, prefix string) {
typeOf := value.Type()
// Compose prefix for everything below current field.
var curPrefix string
if prefix != "" {
curPrefix = prefix
if !strings.HasSuffix(curPrefix, "_") {
curPrefix += "_"
}
}
for i := 0; i < value.NumField(); i++ {
fieldToProcess := value.Field(i)
fieldToProcessType := typeOf.Field(i)
// If currently processed field - interface, then we should
// get underlying value.
//if fieldToProcess.Kind() == reflect.Interface {
// fieldToProcess = fieldToProcess.Elem()
//}
// In 99% of cases we will get uninitialized things we should
// initialize.
switch fieldToProcess.Kind() {
case reflect.Ptr, reflect.Map, reflect.Slice, reflect.Chan:
if fieldToProcess.IsNil() {
printDebug("Field '%s' is nil, initializing new one", fieldToProcessType.Name)
// We should use only exported fields as unexported aren't
// settable using 'reflect' package. Can be possibly solved
// using unsafe pointers?
if fieldToProcess.CanSet() {
fieldToProcess.Set(reflect.New(fieldToProcess.Type().Elem()))
} else {
printDebug("Field '%s' is unexported and will be ignored", fieldToProcessType.Name)
continue
}
fieldToProcess = fieldToProcess.Elem()
}
}
printDebug("Field: '%s', type: %s, (anonymous or embedded: %t)", fieldToProcessType.Name, fieldToProcess.Type().Kind().String(), fieldToProcessType.Anonymous)
// Dealing with embedded things.
if fieldToProcessType.Anonymous {
// We should not allow anything other than struct.
if fieldToProcess.Kind() != reflect.Struct {
printDebug("Field is embedded, but not a struct (%s), which cannot be used", fieldToProcess.Kind().String())
continue
}
}
if fieldToProcess.Kind() != reflect.Struct && !fieldToProcess.CanSet() {
printDebug("Field '%s' can't be set, skipping", fieldToProcessType.Name)
continue
}
printDebug("All underlying elements will have prefix '%s'", curPrefix)
// Hello, I'm recursion and I'm here to make you happy.
// I'll be launched only for structures to get their fields.
if fieldToProcess.Kind() == reflect.Struct {
newElementPrefix := curPrefix
if !fieldToProcessType.Anonymous {
newElementPrefix = strings.ToUpper(newElementPrefix + typeOf.Field(i).Name)
}
composeTree(fieldToProcess, newElementPrefix)
} else {
f := &field{
Name: typeOf.Field(i).Name,
EnvVar: curPrefix + strings.ToUpper(typeOf.Field(i).Name),
Pointer: fieldToProcess,
Kind: fieldToProcess.Kind(),
}
parsedTree = append(parsedTree, f)
printDebug("Field data constructed: %+v", f)
}
}
}