Implement an in-memory databasewqa

pkg/ramdb/record.go

@@ -0,0 +1,51 @@
+package ramdb
+
+import (
+	"crypto/sha256"
+	"encoding/binary"
+	"encoding/json"
+
+	"github.com/google/btree"
+)
+
+type record struct {
+	serialized []byte
+	keyColumn  string
+	key        string
+	id         uint64
+}
+
+// NewRecord returns a pointer to a record populated with data, key, and a hash of the key used for ordering in the tree.
+func NewRecord(key, keyColumn string, data interface{}) (*record, error) {
+	serialized, err := json.Marshal(data)
+	if err != nil {
+		return nil, err
+	}
+
+	var r record
+	r.serialized = serialized
+	r.keyColumn = keyColumn
+	r.key = key
+	r.id = keyHash(key)
+	return &r, nil
+}
+
+func keyHash(s string) uint64 {
+	h := sha256.New()
+	h.Write([]byte(s))
+	sum := h.Sum(nil)
+
+	return binary.BigEndian.Uint64(sum)
+}
+
+// Deserialize unmarshals the serialized data into `into`.
+func (r *record) Deserialize(into interface{}) error {
+	err := json.Unmarshal(r.serialized, &into)
+	return err
+}
+
+// Less is used to order items and for looking up records in the tree.
+func (r *record) Less(than btree.Item) bool {
+	re := than.(*record)
+	return r.id < re.id
+}