1 /*
2 * Copyright (C) 2010 The Android Open Source Project
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
17 #define LOG_TAG "MtpStringBuffer"
18
19 #include <string.h>
20
21 #include "MtpDataPacket.h"
22 #include "MtpStringBuffer.h"
23
24 namespace android {
25
MtpStringBuffer()26 MtpStringBuffer::MtpStringBuffer()
27 : mCharCount(0),
28 mByteCount(1)
29 {
30 mBuffer[0] = 0;
31 }
32
MtpStringBuffer(const char * src)33 MtpStringBuffer::MtpStringBuffer(const char* src)
34 : mCharCount(0),
35 mByteCount(1)
36 {
37 set(src);
38 }
39
MtpStringBuffer(const uint16_t * src)40 MtpStringBuffer::MtpStringBuffer(const uint16_t* src)
41 : mCharCount(0),
42 mByteCount(1)
43 {
44 set(src);
45 }
46
MtpStringBuffer(const MtpStringBuffer & src)47 MtpStringBuffer::MtpStringBuffer(const MtpStringBuffer& src)
48 : mCharCount(src.mCharCount),
49 mByteCount(src.mByteCount)
50 {
51 memcpy(mBuffer, src.mBuffer, mByteCount);
52 }
53
54
~MtpStringBuffer()55 MtpStringBuffer::~MtpStringBuffer() {
56 }
57
set(const char * src)58 void MtpStringBuffer::set(const char* src) {
59 // count the characters
60 int count = 0;
61 char ch;
62 char* dest = (char*)mBuffer;
63
64 while ((ch = *src++) != 0 && count < MTP_STRING_MAX_CHARACTER_NUMBER) {
65 if ((ch & 0x80) == 0) {
66 // single byte character
67 *dest++ = ch;
68 } else if ((ch & 0xE0) == 0xC0) {
69 // two byte character
70 char ch1 = *src++;
71 if (! ch1) {
72 // last character was truncated, so ignore last byte
73 break;
74 }
75
76 *dest++ = ch;
77 *dest++ = ch1;
78 } else if ((ch & 0xF0) == 0xE0) {
79 // 3 byte char
80 char ch1 = *src++;
81 if (! ch1) {
82 // last character was truncated, so ignore last byte
83 break;
84 }
85 char ch2 = *src++;
86 if (! ch2) {
87 // last character was truncated, so ignore last byte
88 break;
89 }
90
91 *dest++ = ch;
92 *dest++ = ch1;
93 *dest++ = ch2;
94 }
95 count++;
96 }
97
98 *dest++ = 0;
99 mByteCount = dest - (char*)mBuffer;
100 mCharCount = count;
101 }
102
set(const uint16_t * src)103 void MtpStringBuffer::set(const uint16_t* src) {
104 int count = 0;
105 uint16_t ch;
106 uint8_t* dest = mBuffer;
107
108 while ((ch = *src++) != 0 && count < MTP_STRING_MAX_CHARACTER_NUMBER) {
109 if (ch >= 0x0800) {
110 *dest++ = (uint8_t)(0xE0 | (ch >> 12));
111 *dest++ = (uint8_t)(0x80 | ((ch >> 6) & 0x3F));
112 *dest++ = (uint8_t)(0x80 | (ch & 0x3F));
113 } else if (ch >= 0x80) {
114 *dest++ = (uint8_t)(0xC0 | (ch >> 6));
115 *dest++ = (uint8_t)(0x80 | (ch & 0x3F));
116 } else {
117 *dest++ = ch;
118 }
119 count++;
120 }
121 *dest++ = 0;
122 mCharCount = count;
123 mByteCount = dest - mBuffer;
124 }
125
readFromPacket(MtpDataPacket * packet)126 bool MtpStringBuffer::readFromPacket(MtpDataPacket* packet) {
127 uint8_t count;
128 if (!packet->getUInt8(count))
129 return false;
130
131 uint8_t* dest = mBuffer;
132 for (int i = 0; i < count; i++) {
133 uint16_t ch;
134
135 if (!packet->getUInt16(ch))
136 return false;
137 if (ch >= 0x0800) {
138 *dest++ = (uint8_t)(0xE0 | (ch >> 12));
139 *dest++ = (uint8_t)(0x80 | ((ch >> 6) & 0x3F));
140 *dest++ = (uint8_t)(0x80 | (ch & 0x3F));
141 } else if (ch >= 0x80) {
142 *dest++ = (uint8_t)(0xC0 | (ch >> 6));
143 *dest++ = (uint8_t)(0x80 | (ch & 0x3F));
144 } else {
145 *dest++ = ch;
146 }
147 }
148 *dest++ = 0;
149 mCharCount = count;
150 mByteCount = dest - mBuffer;
151 return true;
152 }
153
writeToPacket(MtpDataPacket * packet) const154 void MtpStringBuffer::writeToPacket(MtpDataPacket* packet) const {
155 int count = mCharCount;
156 const uint8_t* src = mBuffer;
157 packet->putUInt8(count > 0 ? count + 1 : 0);
158
159 // expand utf8 to 16 bit chars
160 for (int i = 0; i < count; i++) {
161 uint16_t ch;
162 uint16_t ch1 = *src++;
163 if ((ch1 & 0x80) == 0) {
164 // single byte character
165 ch = ch1;
166 } else if ((ch1 & 0xE0) == 0xC0) {
167 // two byte character
168 uint16_t ch2 = *src++;
169 ch = ((ch1 & 0x1F) << 6) | (ch2 & 0x3F);
170 } else {
171 // three byte character
172 uint16_t ch2 = *src++;
173 uint16_t ch3 = *src++;
174 ch = ((ch1 & 0x0F) << 12) | ((ch2 & 0x3F) << 6) | (ch3 & 0x3F);
175 }
176 packet->putUInt16(ch);
177 }
178 // only terminate with zero if string is not empty
179 if (count > 0)
180 packet->putUInt16(0);
181 }
182
183 } // namespace android
184