1 // Copyright 2008 Google Inc.
2 // Author: Lincoln Smith
3 //
4 // Licensed under the Apache License, Version 2.0 (the "License");
5 // you may not use this file except in compliance with the License.
6 // You may obtain a copy of the License at
7 //
8 // http://www.apache.org/licenses/LICENSE-2.0
9 //
10 // Unless required by applicable law or agreed to in writing, software
11 // distributed under the License is distributed on an "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 // See the License for the specific language governing permissions and
14 // limitations under the License.
15
16 #include <config.h>
17 #include "google/vcdecoder.h"
18 #include <string>
19 #include "codetable.h"
20 #include "testing.h"
21 #include "vcdecoder_test.h"
22
23 namespace open_vcdiff {
24 namespace {
25
26
27 // Decode an encoding that uses a RUN instruction to allocate 64MB.
28 class VCDiffLargeTargetTest : public VCDiffDecoderTest {
29 protected:
30 VCDiffLargeTargetTest();
~VCDiffLargeTargetTest()31 virtual ~VCDiffLargeTargetTest() {}
32
33 static const char kLargeRunWindow[];
34 };
35
36 const char VCDiffLargeTargetTest::kLargeRunWindow[] = {
37 0x00, // Win_Indicator: no source segment
38 0x0E, // Length of the delta encoding
39 0xA0, // Size of the target window (0x4000000)
40 0x80, // Size of the target window cont'd
41 0x80, // Size of the target window cont'd
42 0x00, // Size of the target window cont'd
43 0x00, // Delta_indicator (no compression)
44 0x00, // length of data for ADDs and RUNs
45 0x06, // length of instructions section
46 0x00, // length of addresses for COPYs
47 // Interleaved segment
48 0x00, // VCD_RUN size 0
49 0xA0, // Size of RUN (0x4000000)
50 0x80, // Size of RUN cont'd
51 0x80, // Size of RUN cont'd
52 0x00, // Size of RUN cont'd
53 0xBE, // Data for RUN
54 };
55
VCDiffLargeTargetTest()56 VCDiffLargeTargetTest::VCDiffLargeTargetTest() {
57 UseInterleavedFileHeader();
58 }
59
60 // Ensure that, with allow_vcd_target set to false, we can decode any number of
61 // 64MB windows without running out of memory.
TEST_F(VCDiffLargeTargetTest,Decode)62 TEST_F(VCDiffLargeTargetTest, Decode) {
63 // 50 x 64MB = 3.2GB, which should be too large if memory usage accumulates
64 // during each iteration.
65 const int kIterations = 50;
66 decoder_.SetAllowVcdTarget(false);
67 decoder_.SetMaximumTargetFileSize(0x4000000UL * 50);
68 decoder_.StartDecoding(dictionary_.data(), dictionary_.size());
69 EXPECT_TRUE(decoder_.DecodeChunk(delta_file_header_.data(),
70 delta_file_header_.size(),
71 &output_));
72 EXPECT_EQ("", output_);
73 for (int i = 0; i < kIterations; i++) {
74 EXPECT_TRUE(decoder_.DecodeChunk(kLargeRunWindow, sizeof(kLargeRunWindow),
75 &output_));
76 EXPECT_EQ(0x4000000U, output_.size());
77 EXPECT_EQ(static_cast<char>(0xBE), output_[0]);
78 EXPECT_EQ(static_cast<char>(0xBE),
79 output_[output_.size() / 2]); // middle element
80 EXPECT_EQ(static_cast<char>(0xBE),
81 output_[output_.size() - 1]); // last element
82 output_.clear();
83 }
84 EXPECT_TRUE(decoder_.FinishDecoding());
85 }
86
87 // If we don't increase the maximum target file size first, the same test should
88 // produce an error.
TEST_F(VCDiffLargeTargetTest,DecodeReachesMaxFileSize)89 TEST_F(VCDiffLargeTargetTest, DecodeReachesMaxFileSize) {
90 decoder_.SetAllowVcdTarget(false);
91 decoder_.StartDecoding(dictionary_.data(), dictionary_.size());
92 EXPECT_TRUE(decoder_.DecodeChunk(delta_file_header_.data(),
93 delta_file_header_.size(),
94 &output_));
95 EXPECT_EQ("", output_);
96 // The default maximum target file size is 64MB, which just matches the target
97 // data produced by a single iteration.
98 EXPECT_TRUE(decoder_.DecodeChunk(kLargeRunWindow, sizeof(kLargeRunWindow),
99 &output_));
100 EXPECT_EQ(0x4000000U, output_.size());
101 EXPECT_EQ(static_cast<char>(0xBE), output_[0]);
102 EXPECT_EQ(static_cast<char>(0xBE),
103 output_[output_.size() / 2]); // middle element
104 EXPECT_EQ(static_cast<char>(0xBE),
105 output_[output_.size() - 1]); // last element
106 output_.clear();
107 // Trying to decode a second window should exceed the target file size limit.
108 EXPECT_FALSE(decoder_.DecodeChunk(kLargeRunWindow, sizeof(kLargeRunWindow),
109 &output_));
110 }
111
112 } // unnamed namespace
113 } // namespace open_vcdiff
114