1 // Copyright 2017 The PDFium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "core/fxcodec/jbig2/JBig2_BitStream.h"
6
7 #include "testing/gtest/include/gtest/gtest.h"
8
TEST(JBig2_BitStream,ReadNBits)9 TEST(JBig2_BitStream, ReadNBits) {
10 const uint8_t kData[] = {0xb1}; // 10110001
11 CJBig2_BitStream stream(kData, 0);
12
13 uint32_t val1;
14 EXPECT_EQ(0, stream.readNBits(1, &val1));
15 EXPECT_EQ(1U, val1);
16
17 int32_t val2;
18 EXPECT_EQ(0, stream.readNBits(1, &val2));
19 EXPECT_EQ(0, val2);
20
21 EXPECT_EQ(0, stream.readNBits(2, &val2));
22 EXPECT_EQ(3, val2);
23
24 EXPECT_EQ(0, stream.readNBits(4, &val2));
25 EXPECT_EQ(1, val2);
26 }
27
TEST(JBig2_BitStream,ReadNBitsLargerThenData)28 TEST(JBig2_BitStream, ReadNBitsLargerThenData) {
29 const uint8_t kData[] = {0xb1}; // 10110001
30 CJBig2_BitStream stream(kData, 42);
31
32 uint32_t val1;
33 EXPECT_EQ(0, stream.readNBits(10, &val1));
34 EXPECT_EQ(0xb1U, val1);
35 }
36
TEST(JBig2_BitStream,ReadNBitsNullStream)37 TEST(JBig2_BitStream, ReadNBitsNullStream) {
38 CJBig2_BitStream stream({}, 0);
39
40 uint32_t val1;
41 EXPECT_EQ(-1, stream.readNBits(1, &val1));
42
43 int32_t val2;
44 EXPECT_EQ(-1, stream.readNBits(2, &val2));
45 }
46
TEST(JBig2_BitStream,ReadNBitsOutOfBounds)47 TEST(JBig2_BitStream, ReadNBitsOutOfBounds) {
48 const uint8_t kData[] = {0xb1}; // 10110001
49 CJBig2_BitStream stream(kData, 42);
50
51 uint32_t val1;
52 EXPECT_EQ(0, stream.readNBits(8, &val1));
53
54 int32_t val2;
55 EXPECT_EQ(-1, stream.readNBits(2, &val2));
56 }
57
TEST(JBig2_BitStream,ReadNBitsWhereNIs36)58 TEST(JBig2_BitStream, ReadNBitsWhereNIs36) {
59 const uint8_t kData[] = {0xb0, 0x01, 0x00, 0x00, 0x40};
60 CJBig2_BitStream stream(kData, 42);
61
62 // This will shift off the top two bits and they end up lost.
63 uint32_t val1;
64 EXPECT_EQ(0, stream.readNBits(34, &val1));
65 EXPECT_EQ(0xc0040001U, val1);
66 }
67