99 lines
2.1 KiB
Go
99 lines
2.1 KiB
Go
package structr
|
|
|
|
import (
|
|
"fmt"
|
|
"reflect"
|
|
"sync"
|
|
"unicode"
|
|
"unicode/utf8"
|
|
|
|
"github.com/zeebo/xxh3"
|
|
)
|
|
|
|
// findField will search for a struct field with given set of names, where names is a len > 0 slice of names account for nesting.
|
|
func findField(t reflect.Type, names []string, allowZero bool) (sfield structfield, ok bool) {
|
|
var (
|
|
// isExported returns whether name is exported
|
|
// from a package; can be func or struct field.
|
|
isExported = func(name string) bool {
|
|
r, _ := utf8.DecodeRuneInString(name)
|
|
return unicode.IsUpper(r)
|
|
}
|
|
|
|
// popName pops the next name from
|
|
// the provided slice of field names.
|
|
popName = func() string {
|
|
// Pop next name.
|
|
name := names[0]
|
|
names = names[1:]
|
|
|
|
// Ensure valid name.
|
|
if !isExported(name) {
|
|
panicf("field is not exported: %s", name)
|
|
}
|
|
|
|
return name
|
|
}
|
|
|
|
// field is the iteratively searched-for
|
|
// struct field value in below loop.
|
|
field reflect.StructField
|
|
)
|
|
|
|
for len(names) > 0 {
|
|
// Pop next name.
|
|
name := popName()
|
|
|
|
// Follow any ptrs leading to field.
|
|
for t.Kind() == reflect.Pointer {
|
|
t = t.Elem()
|
|
}
|
|
|
|
if t.Kind() != reflect.Struct {
|
|
// The end type after following ptrs must be struct.
|
|
panicf("field %s is not struct (ptr): %s", t, name)
|
|
}
|
|
|
|
// Look for next field by name.
|
|
field, ok = t.FieldByName(name)
|
|
if !ok {
|
|
return
|
|
}
|
|
|
|
// Append next set of indices required to reach field.
|
|
sfield.index = append(sfield.index, field.Index...)
|
|
|
|
// Set the next type.
|
|
t = field.Type
|
|
}
|
|
|
|
// Get final type hash func.
|
|
sfield.hasher = hasher(t)
|
|
|
|
return
|
|
}
|
|
|
|
// panicf provides a panic with string formatting.
|
|
func panicf(format string, args ...any) {
|
|
panic(fmt.Sprintf(format, args...))
|
|
}
|
|
|
|
// hashPool provides a memory pool of xxh3
|
|
// hasher objects used indexing field vals.
|
|
var hashPool sync.Pool
|
|
|
|
// gethashbuf fetches hasher from memory pool.
|
|
func getHasher() *xxh3.Hasher {
|
|
v := hashPool.Get()
|
|
if v == nil {
|
|
v = new(xxh3.Hasher)
|
|
}
|
|
return v.(*xxh3.Hasher)
|
|
}
|
|
|
|
// putHasher replaces hasher in memory pool.
|
|
func putHasher(h *xxh3.Hasher) {
|
|
h.Reset()
|
|
hashPool.Put(h)
|
|
}
|