1 // Copyright 2014 PDFium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
6
7 #include "core/fxcodec/jbig2/JBig2_HuffmanTable.h"
8
9 #include <algorithm>
10 #include <limits>
11 #include <vector>
12
13 #include "core/fxcodec/jbig2/JBig2_BitStream.h"
14 #include "core/fxcodec/jbig2/JBig2_Define.h"
15 #include "core/fxcodec/jbig2/JBig2_HuffmanTable_Standard.h"
16 #include "core/fxcrt/fx_memory.h"
17 #include "third_party/base/numerics/safe_math.h"
18
CJBig2_HuffmanTable(const JBig2TableLine * pTable,uint32_t nLines,bool bHTOOB)19 CJBig2_HuffmanTable::CJBig2_HuffmanTable(const JBig2TableLine* pTable,
20 uint32_t nLines,
21 bool bHTOOB)
22 : m_bOK(true), HTOOB(bHTOOB), NTEMP(nLines) {
23 ParseFromStandardTable(pTable);
24 }
25
CJBig2_HuffmanTable(CJBig2_BitStream * pStream)26 CJBig2_HuffmanTable::CJBig2_HuffmanTable(CJBig2_BitStream* pStream)
27 : HTOOB(false), NTEMP(0) {
28 m_bOK = ParseFromCodedBuffer(pStream);
29 }
30
~CJBig2_HuffmanTable()31 CJBig2_HuffmanTable::~CJBig2_HuffmanTable() {}
32
ParseFromStandardTable(const JBig2TableLine * pTable)33 void CJBig2_HuffmanTable::ParseFromStandardTable(const JBig2TableLine* pTable) {
34 PREFLEN.resize(NTEMP);
35 RANGELEN.resize(NTEMP);
36 RANGELOW.resize(NTEMP);
37 for (uint32_t i = 0; i < NTEMP; ++i) {
38 PREFLEN[i] = pTable[i].PREFLEN;
39 RANGELEN[i] = pTable[i].RANDELEN;
40 RANGELOW[i] = pTable[i].RANGELOW;
41 }
42 InitCodes();
43 }
44
ParseFromCodedBuffer(CJBig2_BitStream * pStream)45 bool CJBig2_HuffmanTable::ParseFromCodedBuffer(CJBig2_BitStream* pStream) {
46 unsigned char cTemp;
47 if (pStream->read1Byte(&cTemp) == -1)
48 return false;
49
50 HTOOB = !!(cTemp & 0x01);
51 unsigned char HTPS = ((cTemp >> 1) & 0x07) + 1;
52 unsigned char HTRS = ((cTemp >> 4) & 0x07) + 1;
53 uint32_t HTLOW;
54 uint32_t HTHIGH;
55 if (pStream->readInteger(&HTLOW) == -1 ||
56 pStream->readInteger(&HTHIGH) == -1 ||
57 HTLOW > static_cast<uint32_t>(std::numeric_limits<int>::max()) ||
58 HTHIGH > static_cast<uint32_t>(std::numeric_limits<int>::max())) {
59 return false;
60 }
61
62 const int low = static_cast<int>(HTLOW);
63 const int high = static_cast<int>(HTHIGH);
64 if (low > high)
65 return false;
66
67 ExtendBuffers(false);
68 pdfium::base::CheckedNumeric<int> cur_low = low;
69 do {
70 if ((pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1) ||
71 (pStream->readNBits(HTRS, &RANGELEN[NTEMP]) == -1) ||
72 (static_cast<size_t>(RANGELEN[NTEMP]) >= 8 * sizeof(cur_low))) {
73 return false;
74 }
75 RANGELOW[NTEMP] = cur_low.ValueOrDie();
76
77 if (RANGELEN[NTEMP] >= 32)
78 return false;
79
80 cur_low += (1 << RANGELEN[NTEMP]);
81 if (!cur_low.IsValid())
82 return false;
83 ExtendBuffers(true);
84 } while (cur_low.ValueOrDie() < high);
85
86 if (pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1)
87 return false;
88
89 RANGELEN[NTEMP] = 32;
90 RANGELOW[NTEMP] = low - 1;
91 ExtendBuffers(true);
92
93 if (pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1)
94 return false;
95
96 RANGELEN[NTEMP] = 32;
97 RANGELOW[NTEMP] = high;
98 ExtendBuffers(true);
99
100 if (HTOOB) {
101 if (pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1)
102 return false;
103
104 ++NTEMP;
105 }
106
107 return InitCodes();
108 }
109
InitCodes()110 bool CJBig2_HuffmanTable::InitCodes() {
111 int lenmax = 0;
112 for (uint32_t i = 0; i < NTEMP; ++i)
113 lenmax = std::max(PREFLEN[i], lenmax);
114
115 CODES.resize(NTEMP);
116 std::vector<int> LENCOUNT(lenmax + 1);
117 std::vector<int> FIRSTCODE(lenmax + 1);
118 for (int len : PREFLEN)
119 ++LENCOUNT[len];
120
121 FIRSTCODE[0] = 0;
122 LENCOUNT[0] = 0;
123 for (int i = 1; i <= lenmax; ++i) {
124 pdfium::base::CheckedNumeric<int> shifted;
125 shifted = FIRSTCODE[i - 1] + LENCOUNT[i - 1];
126 shifted <<= 1;
127 if (!shifted.IsValid())
128 return false;
129
130 FIRSTCODE[i] = shifted.ValueOrDie();
131 int CURCODE = FIRSTCODE[i];
132 for (uint32_t j = 0; j < NTEMP; ++j) {
133 if (PREFLEN[j] == i)
134 CODES[j] = CURCODE++;
135 }
136 }
137
138 return true;
139 }
140
ExtendBuffers(bool increment)141 void CJBig2_HuffmanTable::ExtendBuffers(bool increment) {
142 if (increment)
143 ++NTEMP;
144
145 size_t size = PREFLEN.size();
146 if (NTEMP < size)
147 return;
148
149 size += 16;
150 ASSERT(NTEMP < size);
151 PREFLEN.resize(size);
152 RANGELEN.resize(size);
153 RANGELOW.resize(size);
154 }
155