1 files changed, 131 insertions, 0 deletions
diff --git a/src/lib/compress/flate/flate_test.go b/src/lib/compress/flate/flate_test.go
new file mode 100644
index 000000000..309606ecb
--- /dev/null
+++ b/src/lib/compress/flate/flate_test.go
@@ -0,0 +1,131 @@
+// Copyright 2009 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 test tests some internals of the flate package.
+// The tests in package compress/gzip serve as the
+// end-to-end test of the inflater.
+
+package flate
+
+import (
+	"bufio";
+	"compress/flate";
+	"io";
+	"os";
+	"reflect";
+	"strconv";
+	"testing";
+)
+
+// The Huffman code lengths used by the fixed-format Huffman blocks.
+var fixedHuffmanBits = [...]int {
+	// 0-143 length 8
+	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+
+	// 144-255 length 9
+	9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+	9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+	9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+	9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+	9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+	9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+	9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+
+	// 256-279 length 7
+	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+	7, 7, 7, 7, 7, 7, 7, 7,
+
+	// 280-287 length 8
+	8, 8, 8, 8, 8, 8, 8, 8,
+}
+
+type InitDecoderTest struct {
+	in []int;
+	out huffmanDecoder;
+	ok bool;
+}
+
+var initDecoderTests = []*InitDecoderTest{
+	// Example from Connell 1973,
+	&InitDecoderTest{
+		[]int{ 3, 5, 2, 4, 3, 5, 5, 4, 4, 3, 4, 5 },
+		huffmanDecoder {
+			2, 5,
+			[maxCodeLen+1]int{ 2: 0, 4, 13, 31 },
+			[maxCodeLen+1]int{ 2: 0, 1, 6, 20 },
+			// Paper used different code assignment:
+			// 2, 9, 4, 0, 10, 8, 3, 7, 1, 5, 11, 6
+			// Reordered here so that codes of same length
+			// are assigned to increasing numbers.
+			[]int{ 2, 0, 4, 9, 3, 7, 8, 10, 1, 5, 6, 11 },
+		},
+		true,
+	},
+
+	// Example from RFC 1951 section 3.2.2
+	&InitDecoderTest{
+		[]int{ 2, 1, 3, 3 },
+		huffmanDecoder {
+			1, 3,
+			[maxCodeLen+1]int{ 1: 0, 2, 7, },
+			[maxCodeLen+1]int{ 1: 0, 1, 4, },
+			[]int{ 1, 0, 2, 3 },
+		},
+		true,
+	},
+
+	// Second example from RFC 1951 section 3.2.2
+	&InitDecoderTest{
+		[]int{ 3, 3, 3, 3, 3, 2, 4, 4 },
+		huffmanDecoder{
+			2, 4,
+			[maxCodeLen+1]int{ 2: 0, 6, 15, },
+			[maxCodeLen+1]int{ 2: 0, 1, 8, },
+			[]int{ 5, 0, 1, 2, 3, 4, 6, 7 },
+		},
+		true,
+	},
+
+	// Static Huffman codes (RFC 1951 section 3.2.6)
+	&InitDecoderTest{
+		&fixedHuffmanBits,
+		fixedHuffmanDecoder,
+		true,
+	},
+	
+	// Illegal input.
+	&InitDecoderTest{
+		[]int{ },
+		huffmanDecoder{ },
+		false,
+	},
+
+	// Illegal input.
+	&InitDecoderTest{
+		[]int{ 0, 0, 0, 0, 0, 0, 0, },
+		huffmanDecoder{ },
+		false,
+	},
+}
+
+func TestInitDecoder(t *testing.T) {
+	for i, tt := range initDecoderTests {
+		var h huffmanDecoder;
+		if h.init(tt.in) != tt.ok {
+			t.Errorf("test %d: init = %v", i, !tt.ok);
+			continue;
+		}
+		if !reflect.DeepEqual(&h, &tt.out) {
+			t.Errorf("test %d:\nhave %v\nwant %v", i, h, tt.out);
+		}
+	}
+}