1 files changed, 85 insertions, 0 deletions
diff --git a/vendor/github.com/mattermost/rsc/gf256/blog_test.go b/vendor/github.com/mattermost/rsc/gf256/blog_test.go
new file mode 100644
index 000000000..12cc7deb0
--- /dev/null
+++ b/vendor/github.com/mattermost/rsc/gf256/blog_test.go
@@ -0,0 +1,85 @@
+// Copyright 2012 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file contains a straightforward implementation of
+// Reed-Solomon encoding, along with a benchmark.
+// It goes with http://research.swtch.com/field.
+//
+// For an optimized implementation, see gf256.go.
+
+package gf256
+
+import (
+	"bytes"
+	"fmt"
+	"testing"
+)
+
+// BlogECC writes to check the error correcting code bytes
+// for data using the given Reed-Solomon parameters.
+func BlogECC(rs *RSEncoder, m []byte, check []byte) {
+	if len(check) < rs.c {
+		panic("gf256: invalid check byte length")
+	}
+	if rs.c == 0 {
+		return
+	}
+
+	// The check bytes are the remainder after dividing
+	// data padded with c zeros by the generator polynomial.  
+
+	// p = data padded with c zeros.
+	var p []byte
+	n := len(m) + rs.c
+	if len(rs.p) >= n {
+		p = rs.p
+	} else {
+		p = make([]byte, n)
+	}
+	copy(p, m)
+	for i := len(m); i < len(p); i++ {
+		p[i] = 0
+	}
+
+	gen := rs.gen
+
+	// Divide p by gen, leaving the remainder in p[len(data):].
+	// p[0] is the most significant term in p, and
+	// gen[0] is the most significant term in the generator.
+	for i := 0; i < len(m); i++ {
+		k := f.Mul(p[i], f.Inv(gen[0])) // k = pi / g0
+		// p -= k·g
+		for j, g := range gen {
+			p[i+j] = f.Add(p[i+j], f.Mul(k, g))
+		}
+	}
+
+	copy(check, p[len(m):])
+	rs.p = p
+}
+
+func BenchmarkBlogECC(b *testing.B) {
+	data := []byte{0x10, 0x20, 0x0c, 0x56, 0x61, 0x80, 0xec, 0x11, 0xec, 0x11, 0xec, 0x11, 0xec, 0x11, 0xec, 0x11, 0x10, 0x20, 0x0c, 0x56, 0x61, 0x80, 0xec, 0x11, 0xec, 0x11, 0xec, 0x11, 0xec, 0x11, 0xec, 0x11}
+	check := []byte{0x29, 0x41, 0xb3, 0x93, 0x8, 0xe8, 0xa3, 0xe7, 0x63, 0x8f}
+	out := make([]byte, len(check))
+	rs := NewRSEncoder(f, len(check))
+	for i := 0; i < b.N; i++ {
+		BlogECC(rs, data, out)
+	}
+	b.SetBytes(int64(len(data)))
+	if !bytes.Equal(out, check) {
+		fmt.Printf("have %#v want %#v\n", out, check)
+	}
+}
+
+func TestBlogECC(t *testing.T) {
+	data := []byte{0x10, 0x20, 0x0c, 0x56, 0x61, 0x80, 0xec, 0x11, 0xec, 0x11, 0xec, 0x11, 0xec, 0x11, 0xec, 0x11}
+	check := []byte{0xa5, 0x24, 0xd4, 0xc1, 0xed, 0x36, 0xc7, 0x87, 0x2c, 0x55}
+	out := make([]byte, len(check))
+	rs := NewRSEncoder(f, len(check))
+	BlogECC(rs, data, out)
+	if !bytes.Equal(out, check) {
+		t.Errorf("have %x want %x", out, check)
+	}
+}