cmd, core, eth, light, trie: add trie read caching layer

vendor/github.com/allegro/bigcache/encoding.go

@@ -0,0 +1,62 @@
+package bigcache
+
+import (
+	"encoding/binary"
+)
+
+const (
+	timestampSizeInBytes = 8                                                       // Number of bytes used for timestamp
+	hashSizeInBytes      = 8                                                       // Number of bytes used for hash
+	keySizeInBytes       = 2                                                       // Number of bytes used for size of entry key
+	headersSizeInBytes   = timestampSizeInBytes + hashSizeInBytes + keySizeInBytes // Number of bytes used for all headers
+)
+
+func wrapEntry(timestamp uint64, hash uint64, key string, entry []byte, buffer *[]byte) []byte {
+	keyLength := len(key)
+	blobLength := len(entry) + headersSizeInBytes + keyLength
+
+	if blobLength > len(*buffer) {
+		*buffer = make([]byte, blobLength)
+	}
+	blob := *buffer
+
+	binary.LittleEndian.PutUint64(blob, timestamp)
+	binary.LittleEndian.PutUint64(blob[timestampSizeInBytes:], hash)
+	binary.LittleEndian.PutUint16(blob[timestampSizeInBytes+hashSizeInBytes:], uint16(keyLength))
+	copy(blob[headersSizeInBytes:], key)
+	copy(blob[headersSizeInBytes+keyLength:], entry)
+
+	return blob[:blobLength]
+}
+
+func readEntry(data []byte) []byte {
+	length := binary.LittleEndian.Uint16(data[timestampSizeInBytes+hashSizeInBytes:])
+
+	// copy on read
+	dst := make([]byte, len(data)-int(headersSizeInBytes+length))
+	copy(dst, data[headersSizeInBytes+length:])
+
+	return dst
+}
+
+func readTimestampFromEntry(data []byte) uint64 {
+	return binary.LittleEndian.Uint64(data)
+}
+
+func readKeyFromEntry(data []byte) string {
+	length := binary.LittleEndian.Uint16(data[timestampSizeInBytes+hashSizeInBytes:])
+
+	// copy on read
+	dst := make([]byte, length)
+	copy(dst, data[headersSizeInBytes:headersSizeInBytes+length])
+
+	return bytesToString(dst)
+}
+
+func readHashFromEntry(data []byte) uint64 {
+	return binary.LittleEndian.Uint64(data[timestampSizeInBytes:])
+}
+
+func resetKeyFromEntry(data []byte) {
+	binary.LittleEndian.PutUint64(data[timestampSizeInBytes:], 0)
+}