value_append.go

package store

import "fmt"

func (b *baseStore) Append(ord uint64, key string, value []byte) error {
	var newVal []byte
	oldVal, found := b.GetAt(ord, key)
	if !found {
		newVal = make([]byte, len(value))
		copy(newVal[0:], value)
	} else {
		newLen := uint64(len(oldVal) + len(value))
		if b.appendLimit > 0 && newLen >= b.appendLimit {
			return fmt.Errorf("append would exceed limit of %d bytes", b.appendLimit)
		}

		newVal = make([]byte, len(oldVal)+len(value))
		copy(newVal[0:], oldVal)
		copy(newVal[len(oldVal):], value)
	}
	b.set(ord, key, newVal)

	return nil
}