1 /*
2 * Copyright 2011 Google Inc. All Rights Reserved.
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 #if defined (WIN32)
18 #include <windows.h>
19 #endif
20
21 #include <string.h>
22
23 #include "sfntly/port/memory_input_stream.h"
24 #include "sfntly/port/exception_type.h"
25
26 namespace sfntly {
27
MemoryInputStream()28 MemoryInputStream::MemoryInputStream()
29 : buffer_(NULL),
30 position_(0),
31 length_(0) {
32 }
33
~MemoryInputStream()34 MemoryInputStream::~MemoryInputStream() {
35 Close();
36 }
37
Available()38 int32_t MemoryInputStream::Available() {
39 return length_ - position_;
40 }
41
Close()42 void MemoryInputStream::Close() {
43 }
44
Mark(int32_t readlimit)45 void MemoryInputStream::Mark(int32_t readlimit) {
46 // NOP
47 UNREFERENCED_PARAMETER(readlimit);
48 }
49
MarkSupported()50 bool MemoryInputStream::MarkSupported() {
51 return false;
52 }
53
Read()54 int32_t MemoryInputStream::Read() {
55 if (!buffer_) {
56 #if !defined (SFNTLY_NO_EXCEPTION)
57 throw IOException("no memory attached");
58 #endif
59 return 0;
60 }
61 if (position_ >= length_) {
62 #if !defined (SFNTLY_NO_EXCEPTION)
63 throw IOException("eof reached");
64 #endif
65 return 0;
66 }
67 byte_t value = buffer_[position_++];
68 return value;
69 }
70
Read(ByteVector * b)71 int32_t MemoryInputStream::Read(ByteVector* b) {
72 return Read(b, 0, b->size());
73 }
74
Read(ByteVector * b,int32_t offset,int32_t length)75 int32_t MemoryInputStream::Read(ByteVector* b, int32_t offset, int32_t length) {
76 assert(b);
77 if (!buffer_) {
78 #if !defined (SFNTLY_NO_EXCEPTION)
79 throw IOException("no memory attached");
80 #endif
81 return 0;
82 }
83 if (position_ >= length_) {
84 #if !defined (SFNTLY_NO_EXCEPTION)
85 throw IOException("eof reached");
86 #endif
87 return 0;
88 }
89 size_t read_count = std::min<size_t>(length_ - position_, length);
90 if (b->size() < (size_t)(offset + read_count)) {
91 b->resize((size_t)(offset + read_count));
92 }
93 memcpy(&((*b)[offset]), buffer_ + position_, read_count);
94 position_ += read_count;
95 return read_count;
96 }
97
Reset()98 void MemoryInputStream::Reset() {
99 // NOP
100 }
101
Skip(int64_t n)102 int64_t MemoryInputStream::Skip(int64_t n) {
103 if (!buffer_) {
104 #if !defined (SFNTLY_NO_EXCEPTION)
105 throw IOException("no memory attached");
106 #endif
107 return 0;
108 }
109 int64_t skip_count = 0;
110 if (n < 0) { // move backwards
111 skip_count = std::max<int64_t>(0 - (int64_t)position_, n);
112 position_ -= (size_t)(0 - skip_count);
113 } else {
114 skip_count = std::min<size_t>(length_ - position_, (size_t)n);
115 position_ += (size_t)skip_count;
116 }
117 return skip_count;
118 }
119
Unread(ByteVector * b)120 void MemoryInputStream::Unread(ByteVector* b) {
121 Unread(b, 0, b->size());
122 }
123
Unread(ByteVector * b,int32_t offset,int32_t length)124 void MemoryInputStream::Unread(ByteVector* b, int32_t offset, int32_t length) {
125 assert(b);
126 assert(b->size() >= size_t(offset + length));
127 if (!buffer_) {
128 #if !defined (SFNTLY_NO_EXCEPTION)
129 throw IOException("no memory attached");
130 #endif
131 return;
132 }
133 size_t unread_count = std::min<size_t>(position_, length);
134 position_ -= unread_count;
135 Read(b, offset, length);
136 position_ -= unread_count;
137 }
138
Attach(const byte_t * buffer,size_t length)139 bool MemoryInputStream::Attach(const byte_t* buffer, size_t length) {
140 assert(buffer);
141 assert(length);
142 buffer_ = buffer;
143 length_ = length;
144 return true;
145 }
146
147 } // namespace sfntly
148