OLD | NEW |
| (Empty) |
1 // Copyright 2016 The Chromium 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 #include "net/http2/decoder/decode_buffer.h" | |
6 | |
7 namespace net { | |
8 | |
9 bool DecodeBuffer::SlowDecodeUnsignedInt(uint32_t field_size, | |
10 uint32_t field_offset, | |
11 uint32_t* decode_offset, | |
12 uint32_t* value) { | |
13 DCHECK_LT(0u, field_size); | |
14 DCHECK_LE(field_size, 4u); | |
15 DCHECK(decode_offset != nullptr); | |
16 DCHECK_LE(field_offset, *decode_offset); | |
17 const uint32_t next_field_offset = field_offset + field_size; | |
18 if (*decode_offset == field_offset) { | |
19 // Starting to decode field. It is possible we will reach this point | |
20 // twice, once when we've just exhausted the input, and once when | |
21 // resuming decoding with a new input buffer. | |
22 // Clear the field; we do NOT assume that the caller has done so | |
23 // previously. | |
24 *value = 0; | |
25 } else if (*decode_offset >= next_field_offset) { | |
26 // We already decoded this field. | |
27 return true; | |
28 } | |
29 do { | |
30 if (Empty()) { | |
31 return false; // Not done decoding. | |
32 } | |
33 *value = *value << 8 | DecodeUInt8(); | |
34 (*decode_offset)++; | |
35 } while (*decode_offset < next_field_offset); | |
36 return true; | |
37 } | |
38 | |
39 bool DecodeBuffer::SlowDecodeUInt8(uint32_t field_offset, | |
40 uint32_t* decode_offset, | |
41 uint8_t* value) { | |
42 uint32_t tmp = *value; | |
43 const bool done = SlowDecodeUnsignedInt(1 /* field_size */, field_offset, | |
44 decode_offset, &tmp); | |
45 *value = tmp & 0xff; | |
46 DCHECK_EQ(tmp, *value); | |
47 return done; | |
48 } | |
49 | |
50 bool DecodeBuffer::SlowDecodeUInt16(uint32_t field_offset, | |
51 uint32_t* decode_offset, | |
52 uint16_t* value) { | |
53 uint32_t tmp = *value; | |
54 const bool done = SlowDecodeUnsignedInt(2 /* field_size */, field_offset, | |
55 decode_offset, &tmp); | |
56 *value = tmp & 0xffff; | |
57 DCHECK_EQ(tmp, *value); | |
58 return done; | |
59 } | |
60 | |
61 bool DecodeBuffer::SlowDecodeUInt24(uint32_t field_offset, | |
62 uint32_t* decode_offset, | |
63 uint32_t* value) { | |
64 uint32_t tmp = *value; | |
65 const bool done = SlowDecodeUnsignedInt(3 /* field_size */, field_offset, | |
66 decode_offset, &tmp); | |
67 *value = tmp & 0xffffff; | |
68 DCHECK_EQ(tmp, *value); | |
69 return done; | |
70 } | |
71 | |
72 bool DecodeBuffer::SlowDecodeUInt31(uint32_t field_offset, | |
73 uint32_t* decode_offset, | |
74 uint32_t* value) { | |
75 uint32_t tmp = *value; | |
76 const bool done = SlowDecodeUnsignedInt(4 /* field_size */, field_offset, | |
77 decode_offset, &tmp); | |
78 *value = tmp & 0x7fffffff; | |
79 DCHECK_EQ(tmp & 0x7fffffff, *value); | |
80 return done; | |
81 } | |
82 | |
83 bool DecodeBuffer::SlowDecodeUInt32(uint32_t field_offset, | |
84 uint32_t* decode_offset, | |
85 uint32_t* value) { | |
86 return SlowDecodeUnsignedInt(4 /* field_size */, field_offset, decode_offset, | |
87 value); | |
88 } | |
89 | |
90 } // namespace net | |
OLD | NEW |