wp

util/io_test.go

@@ -1,8 +1,14 @@
 package util
 
 import (
+	"bytes"
+	"fmt"
 	"hash/crc32"
+	"io"
+	"os"
 	"testing"
+
+	"gordenko.dev/dima/textutil"
 )
 
 var page = make([]byte, 4096)
@@ -19,3 +25,38 @@ func BenchmarkCRC32IEEE(b *testing.B) {
 		crc32.Checksum(page, ieeeTable)
 	}
 }
+
+func TestHash(t *testing.T) {
+	raw, err := os.ReadFile("../b")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	buf, err := textutil.ParseHex(string(raw))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	fmt.Println(CalculateCRC32(buf))
+
+	w := bytes.NewBuffer(nil)
+	w.Write([]byte{
+		0, 0, 0, 0, 0, 0, 0, 0, 0, // size (max 9 byte)
+	})
+
+	hasher := NewHasher()
+
+	multi := io.MultiWriter(w, hasher)
+
+	i := 0
+	for i < len(buf) {
+		end := i + 50
+		if end >= len(buf) {
+			end = len(buf)
+		}
+		multi.Write(buf[i:end])
+		i += 50
+	}
+
+	fmt.Println(hasher.Sum32())
+}