// 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 decompressor.
package flate
import (
"bytes"
"encoding/hex"
"io"
"io/ioutil"
"strings"
"testing"
)
// The following test should not panic.
func TestIssue5915(t *testing.T) {
bits := []int{4, 0, 0, 6, 4, 3, 2, 3, 3, 4, 4, 5, 0, 0, 0, 0, 5, 5, 6,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 11, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 7, 8, 6, 0, 11, 0, 8, 0, 6, 6, 10, 8}
var h huffmanDecoder
if h.init(bits) {
t.Fatalf("Given sequence of bits is bad, and should not succeed.")
}
}
// The following test should not panic.
func TestIssue5962(t *testing.T) {
bits := []int{4, 0, 0, 6, 4, 3, 2, 3, 3, 4, 4, 5, 0, 0, 0, 0,
5, 5, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 11}
var h huffmanDecoder
if h.init(bits) {
t.Fatalf("Given sequence of bits is bad, and should not succeed.")
}
}
// The following test should not panic.
func TestIssue6255(t *testing.T) {
bits1 := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11}
bits2 := []int{11, 13}
var h huffmanDecoder
if !h.init(bits1) {
t.Fatalf("Given sequence of bits is good and should succeed.")
}
if h.init(bits2) {
t.Fatalf("Given sequence of bits is bad and should not succeed.")
}
}
func TestInvalidEncoding(t *testing.T) {
// Initialize Huffman decoder to recognize "0".
var h huffmanDecoder
if !h.init([]int{1}) {
t.Fatal("Failed to initialize Huffman decoder")
}
// Initialize decompressor with invalid Huffman coding.
var f decompressor
f.r = bytes.NewReader([]byte{0xff})
_, err := f.huffSym(&h)
if err == nil {
t.Fatal("Should have rejected invalid bit sequence")
}
}
func TestInvalidBits(t *testing.T) {
oversubscribed := []int{1, 2, 3, 4, 4, 5}
incomplete := []int{1, 2, 4, 4}
var h huffmanDecoder
if h.init(oversubscribed) {
t.Fatal("Should reject oversubscribed bit-length set")
}
if h.init(incomplete) {
t.Fatal("Should reject incomplete bit-length set")
}
}
func TestStreams(t *testing.T) {
// To verify any of these hexstrings as valid or invalid flate streams
// according to the C zlib library, you can use the Python wrapper library:
// >>> hex_string = "010100feff11"
// >>> import zlib
// >>> zlib.decompress(hex_string.decode("hex"), -15) # Negative means raw DEFLATE
// '\x11'
testCases := []struct {
desc string // Description of the stream
stream string // Hexstring of the input DEFLATE stream
want string // Expected result. Use "fail" to expect failure
}{{
"degenerate HCLenTree",
"05e0010000000000100000000000000000000000000000000000000000000000" +
"00000000000000000004",
"fail",
}, {
"complete HCLenTree, empty HLitTree, empty HDistTree",
"05e0010400000000000000000000000000000000000000000000000000000000" +
"00000000000000000010",
"fail",
}, {
"empty HCLenTree",
"05e0010000000000000000000000000000000000000000000000000000000000" +
"00000000000000000010",
"fail",
}, {
"complete HCLenTree, complete HLitTree, empty HDistTree, use missing HDist symbol",
"000100feff000de0010400000000100000000000000000000000000000000000" +
"0000000000000000000000000000002c",
"fail",
}, {
"complete HCLenTree, complete HLitTree, degenerate HDistTree, use missing HDist symbol",
"000100feff000de0010000000000000000000000000000000000000000000000" +
"00000000000000000610000000004070",
"fail",
}, {
"complete HCLenTree, empty HLitTree, empty HDistTree",
"05e0010400000000100400000000000000000000000000000000000000000000" +
"0000000000000000000000000008",
"fail",
}, {
"complete HCLenTree, empty HLitTree, degenerate HDistTree",
"05e0010400000000100400000000000000000000000000000000000000000000" +
"0000000000000000000800000008",
"fail",
}, {
"complete HCLenTree, degenerate HLitTree, degenerate HDistTree, use missing HLit symbol",
"05e0010400000000100000000000000000000000000000000000000000000000" +
"0000000000000000001c",
"fail",
}, {
"complete HCLenTree, complete HLitTree, too large HDistTree",
"edff870500000000200400000000000000000000000000000000000000000000" +
"000000000000000000080000000000000004",
"fail",
}, {
"complete HCLenTree, complete HLitTree, empty HDistTree, excessive repeater code",
"edfd870500000000200400000000000000000000000000000000000000000000" +
"000000000000000000e8b100",
"fail",
}, {
"complete HCLenTree, complete HLitTree, empty HDistTree of normal length 30",
"05fd01240000000000f8ffffffffffffffffffffffffffffffffffffffffffff" +
"ffffffffffffffffff07000000fe01",
"",
}, {
"complete HCLenTree, complete HLitTree, empty HDistTree of excessive length 31",
"05fe01240000000000f8ffffffffffffffffffffffffffffffffffffffffffff" +
"ffffffffffffffffff07000000fc03",
"fail",
}, {
"complete HCLenTree, over-subscribed HLitTree, empty HDistTree",
"05e001240000000000fcffffffffffffffffffffffffffffffffffffffffffff" +
"ffffffffffffffffff07f00f",
"fail",
}, {
"complete HCLenTree, under-subscribed HLitTree, empty HDistTree",
"05e001240000000000fcffffffffffffffffffffffffffffffffffffffffffff" +
"fffffffffcffffffff07f00f",
"fail",
}, {
"complete HCLenTree, complete HLitTree with single code, empty HDistTree",
"05e001240000000000f8ffffffffffffffffffffffffffffffffffffffffffff" +
"ffffffffffffffffff07f00f",
"01",
}, {
"complete HCLenTree, complete HLitTree with multiple codes, empty HDistTree",
"05e301240000000000f8ffffffffffffffffffffffffffffffffffffffffffff" +
"ffffffffffffffffff07807f",
"01",
}, {
"complete HCLenTree, complete HLitTree, degenerate HDistTree, use valid HDist symbol",
"000100feff000de0010400000000100000000000000000000000000000000000" +
"0000000000000000000000000000003c",
"00000000",
}, {
"complete HCLenTree, degenerate HLitTree, degenerate HDistTree",
"05e0010400000000100000000000000000000000000000000000000000000000" +
"0000000000000000000c",
"",
}, {
"complete HCLenTree, degenerate HLitTree, empty HDistTree",
"05e0010400000000100000000000000000000000000000000000000000000000" +
"00000000000000000004",
"",
}, {
"complete HCLenTree, complete HLitTree, empty HDistTree, spanning repeater code",
"edfd870500000000200400000000000000000000000000000000000000000000" +
"000000000000000000e8b000",
"",
}, {
"complete HCLenTree with length codes, complete HLitTree, empty HDistTree",
"ede0010400000000100000000000000000000000000000000000000000000000" +
"0000000000000000000400004000",
"",
}, {
"complete HCLenTree, complete HLitTree, degenerate HDistTree, use valid HLit symbol 284 with count 31",
"000100feff00ede0010400000000100000000000000000000000000000000000" +
"000000000000000000000000000000040000407f00",
"0000000000000000000000000000000000000000000000000000000000000000" +
"0000000000000000000000000000000000000000000000000000000000000000" +
"0000000000000000000000000000000000000000000000000000000000000000" +
"0000000000000000000000000000000000000000000000000000000000000000" +
"0000000000000000000000000000000000000000000000000000000000000000" +
"0000000000000000000000000000000000000000000000000000000000000000" +
"0000000000000000000000000000000000000000000000000000000000000000" +
"0000000000000000000000000000000000000000000000000000000000000000" +
"000000",
}, {
"complete HCLenTree, complete HLitTree, degenerate HDistTree, use valid HLit and HDist symbols",
"0cc2010d00000082b0ac4aff0eb07d27060000ffff",
"616263616263",
}, {
"fixed block, use reserved symbol 287",
"33180700",
"fail",
}, {
"raw block",
"010100feff11",
"11",
}, {
"issue 10426 - over-subscribed HCLenTree causes a hang",
"344c4a4e494d4b070000ff2e2eff2e2e2e2e2eff",
"fail",
}, {
"issue 11030 - empty HDistTree unexpectedly leads to error",
"05c0070600000080400fff37a0ca",
"",
}, {
"issue 11033 - empty HDistTree unexpectedly leads to error",
"050fb109c020cca5d017dcbca044881ee1034ec149c8980bbc413c2ab35be9dc" +
"b1473449922449922411202306ee97b0383a521b4ffdcf3217f9f7d3adb701",
"3130303634342068652e706870005d05355f7ed957ff084a90925d19e3ebc6d0" +
"c6d7",
}}
for i, tc := range testCases {
data, err := hex.DecodeString(tc.stream)
if err != nil {
t.Fatal(err)
}
data, err = ioutil.ReadAll(NewReader(bytes.NewReader(data)))
if tc.want == "fail" {
if err == nil {
t.Errorf("#%d (%s): got nil error, want non-nil", i, tc.desc)
}
} else {
if err != nil {
t.Errorf("#%d (%s): %v", i, tc.desc, err)
continue
}
if got := hex.EncodeToString(data); got != tc.want {
t.Errorf("#%d (%s):\ngot %q\nwant %q", i, tc.desc, got, tc.want)
}
}
}
}
func TestTruncatedStreams(t *testing.T) {
const data = "\x00\f\x00\xf3\xffhello, world\x01\x00\x00\xff\xff"
for i := 0; i < len(data)-1; i++ {
r := NewReader(strings.NewReader(data[:i]))
_, err := io.Copy(ioutil.Discard, r)
if err != io.ErrUnexpectedEOF {
t.Errorf("io.Copy(%d) on truncated stream: got %v, want %v", i, err, io.ErrUnexpectedEOF)
}
}
}
// Verify that flate.Reader.Read returns (n, io.EOF) instead
// of (n, nil) + (0, io.EOF) when possible.
//
// This helps net/http.Transport reuse HTTP/1 connections more
// aggressively.
//
// See https://github.com/google/go-github/pull/317 for background.
func TestReaderEarlyEOF(t *testing.T) {
t.Parallel()
testSizes := []int{
1, 2, 3, 4, 5, 6, 7, 8,
100, 1000, 10000, 100000,
128, 1024, 16384, 131072,
// Testing multiples of windowSize triggers the case
// where Read will fail to return an early io.EOF.
windowSize * 1, windowSize * 2, windowSize * 3,
}
var maxSize int
for _, n := range testSizes {
if maxSize < n {
maxSize = n
}
}
readBuf := make([]byte, 40)
data := make([]byte, maxSize)
for i := range data {
data[i] = byte(i)
}
for _, sz := range testSizes {
if testing.Short() && sz > windowSize {
continue
}
for _, flush := range []bool{true, false} {
earlyEOF := true // Do we expect early io.EOF?
var buf bytes.Buffer
w, _ := NewWriter(&buf, 5)
w.Write(data[:sz])
if flush {
// If a Flush occurs after all the actual data, the flushing
// semantics dictate that we will observe a (0, io.EOF) since
// Read must return data before it knows that the stream ended.
w.Flush()
earlyEOF = false
}
w.Close()
r := NewReader(&buf)
for {
n, err := r.Read(readBuf)
if err == io.EOF {
// If the availWrite == windowSize, then that means that the
// previous Read returned because the write buffer was full
// and it just so happened that the stream had no more data.
// This situation is rare, but unavoidable.
if r.(*decompressor).dict.availWrite() == windowSize {
earlyEOF = false
}
if n == 0 && earlyEOF {
t.Errorf("On size:%d flush:%v, Read() = (0, io.EOF), want (n, io.EOF)", sz, flush)
}
if n != 0 && !earlyEOF {
t.Errorf("On size:%d flush:%v, Read() = (%d, io.EOF), want (0, io.EOF)", sz, flush, n)
}
break
}
if err != nil {
t.Fatal(err)
}
}
}
}
}
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