1 // Copyright (c) 2009 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 <algorithm>
6
7 #include "base/format_macros.h"
8 #include "base/logging.h"
9 #include "base/strings/stringprintf.h"
10 #include "net/http/http_byte_range.h"
11
12 namespace {
13
14 const int64 kPositionNotSpecified = -1;
15
16 } // namespace
17
18 namespace net {
19
HttpByteRange()20 HttpByteRange::HttpByteRange()
21 : first_byte_position_(kPositionNotSpecified),
22 last_byte_position_(kPositionNotSpecified),
23 suffix_length_(kPositionNotSpecified),
24 has_computed_bounds_(false) {
25 }
26
27 // static
Bounded(int64 first_byte_position,int64 last_byte_position)28 HttpByteRange HttpByteRange::Bounded(int64 first_byte_position,
29 int64 last_byte_position) {
30 HttpByteRange range;
31 range.set_first_byte_position(first_byte_position);
32 range.set_last_byte_position(last_byte_position);
33 return range;
34 }
35
36 // static
RightUnbounded(int64 first_byte_position)37 HttpByteRange HttpByteRange::RightUnbounded(int64 first_byte_position) {
38 HttpByteRange range;
39 range.set_first_byte_position(first_byte_position);
40 return range;
41 }
42
43 // static
Suffix(int64 suffix_length)44 HttpByteRange HttpByteRange::Suffix(int64 suffix_length) {
45 HttpByteRange range;
46 range.set_suffix_length(suffix_length);
47 return range;
48 }
49
IsSuffixByteRange() const50 bool HttpByteRange::IsSuffixByteRange() const {
51 return suffix_length_ != kPositionNotSpecified;
52 }
53
HasFirstBytePosition() const54 bool HttpByteRange::HasFirstBytePosition() const {
55 return first_byte_position_ != kPositionNotSpecified;
56 }
57
HasLastBytePosition() const58 bool HttpByteRange::HasLastBytePosition() const {
59 return last_byte_position_ != kPositionNotSpecified;
60 }
61
IsValid() const62 bool HttpByteRange::IsValid() const {
63 if (suffix_length_ > 0)
64 return true;
65 return (first_byte_position_ >= 0 &&
66 (last_byte_position_ == kPositionNotSpecified ||
67 last_byte_position_ >= first_byte_position_));
68 }
69
GetHeaderValue() const70 std::string HttpByteRange::GetHeaderValue() const {
71 DCHECK(IsValid());
72
73 if (IsSuffixByteRange())
74 return base::StringPrintf("bytes=-%" PRId64, suffix_length());
75
76 DCHECK(HasFirstBytePosition());
77
78 if (!HasLastBytePosition())
79 return base::StringPrintf("bytes=%" PRId64 "-", first_byte_position());
80
81 return base::StringPrintf("bytes=%" PRId64 "-%" PRId64,
82 first_byte_position(), last_byte_position());
83 }
84
ComputeBounds(int64 size)85 bool HttpByteRange::ComputeBounds(int64 size) {
86 if (size < 0)
87 return false;
88 if (has_computed_bounds_)
89 return false;
90 has_computed_bounds_ = true;
91
92 // Empty values.
93 if (!HasFirstBytePosition() &&
94 !HasLastBytePosition() &&
95 !IsSuffixByteRange()) {
96 first_byte_position_ = 0;
97 last_byte_position_ = size - 1;
98 return true;
99 }
100 if (!IsValid())
101 return false;
102 if (IsSuffixByteRange()) {
103 first_byte_position_ = size - std::min(size, suffix_length_);
104 last_byte_position_ = size - 1;
105 return true;
106 }
107 if (first_byte_position_ < size) {
108 if (HasLastBytePosition())
109 last_byte_position_ = std::min(size - 1, last_byte_position_);
110 else
111 last_byte_position_ = size - 1;
112 return true;
113 }
114 return false;
115 }
116
117 } // namespace net
118