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1 // Copyright 2013 The Chromium Authors. All rights reserved. | 1 // Copyright 2013 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #ifndef __STDC_LIMIT_MACROS | |
6 #define __STDC_LIMIT_MACROS | |
7 #endif | |
8 | |
5 #include "nacl_io/memfs/mem_fs_node.h" | 9 #include "nacl_io/memfs/mem_fs_node.h" |
6 | 10 |
11 #include <assert.h> | |
7 #include <errno.h> | 12 #include <errno.h> |
8 #include <string.h> | 13 #include <string.h> |
9 | 14 |
10 #include <algorithm> | 15 #include <algorithm> |
11 | 16 |
12 #include "nacl_io/kernel_handle.h" | 17 #include "nacl_io/kernel_handle.h" |
13 #include "nacl_io/osstat.h" | 18 #include "nacl_io/osstat.h" |
14 #include "sdk_util/auto_lock.h" | 19 #include "sdk_util/auto_lock.h" |
15 | 20 |
16 namespace nacl_io { | 21 namespace nacl_io { |
17 | 22 |
18 namespace { | 23 namespace { |
19 | 24 |
20 // The maximum size to reserve in addition to the requested size. Resize() will | 25 // The maximum size to reserve in addition to the requested size. Resize() will |
21 // allocate twice as much as requested, up to this value. | 26 // allocate twice as much as requested, up to this value. |
22 const size_t kMaxResizeIncrement = 16 * 1024 * 1024; | 27 const size_t kMaxResizeIncrement = 16 * 1024 * 1024; |
23 | 28 |
24 } // namespace | 29 } // namespace |
25 | 30 |
26 MemFsNode::MemFsNode(Filesystem* filesystem) : Node(filesystem) { | 31 MemFsNode::MemFsNode(Filesystem* filesystem) |
32 : Node(filesystem), | |
33 data_(NULL), | |
34 data_capacity_(0) { | |
27 SetType(S_IFREG); | 35 SetType(S_IFREG); |
28 } | 36 } |
29 | 37 |
30 MemFsNode::~MemFsNode() { | 38 MemFsNode::~MemFsNode() { |
31 } | 39 } |
32 | 40 |
33 Error MemFsNode::Read(const HandleAttr& attr, | 41 Error MemFsNode::Read(const HandleAttr& attr, |
34 void* buf, | 42 void* buf, |
35 size_t count, | 43 size_t count, |
36 int* out_bytes) { | 44 int* out_bytes) { |
37 *out_bytes = 0; | 45 *out_bytes = 0; |
38 | 46 |
39 AUTO_LOCK(node_lock_); | 47 AUTO_LOCK(node_lock_); |
40 if (count == 0) | 48 if (count == 0) |
41 return 0; | 49 return 0; |
42 | 50 |
43 size_t size = stat_.st_size; | 51 size_t size = stat_.st_size; |
44 | 52 |
45 if (attr.offs + count > size) { | 53 if (attr.offs + count > size) { |
46 count = size - attr.offs; | 54 count = size - attr.offs; |
47 } | 55 } |
48 | 56 |
49 memcpy(buf, &data_[attr.offs], count); | 57 memcpy(buf, data_ + attr.offs, count); |
50 *out_bytes = static_cast<int>(count); | 58 *out_bytes = static_cast<int>(count); |
51 return 0; | 59 return 0; |
52 } | 60 } |
53 | 61 |
54 Error MemFsNode::Write(const HandleAttr& attr, | 62 Error MemFsNode::Write(const HandleAttr& attr, |
55 const void* buf, | 63 const void* buf, |
56 size_t count, | 64 size_t count, |
57 int* out_bytes) { | 65 int* out_bytes) { |
58 *out_bytes = 0; | 66 *out_bytes = 0; |
59 AUTO_LOCK(node_lock_); | |
60 | 67 |
61 if (count == 0) | 68 if (count == 0) |
62 return 0; | 69 return 0; |
63 | 70 |
64 if (count + attr.offs > static_cast<size_t>(stat_.st_size)) { | 71 AUTO_LOCK(node_lock_); |
65 Resize(count + attr.offs); | 72 off_t new_size = attr.offs + count; |
66 count = stat_.st_size - attr.offs; | 73 if (new_size > stat_.st_size) { |
74 Error error = Resize(new_size); | |
75 if (error) { | |
76 LOG_ERROR("memfs: resize %ld failed: %s", new_size, strerror(error)); | |
binji
2014/08/07 15:22:32
Looks like you need a special macro for off_t?
me
| |
77 return error; | |
78 } | |
67 } | 79 } |
68 | 80 |
69 memcpy(&data_[attr.offs], buf, count); | 81 memcpy(data_ + attr.offs, buf, count); |
70 *out_bytes = static_cast<int>(count); | 82 *out_bytes = static_cast<int>(count); |
71 return 0; | 83 return 0; |
72 } | 84 } |
73 | 85 |
74 Error MemFsNode::FTruncate(off_t new_size) { | 86 Error MemFsNode::FTruncate(off_t new_size) { |
75 AUTO_LOCK(node_lock_); | 87 AUTO_LOCK(node_lock_); |
76 Resize(new_size); | 88 return Resize(new_size); |
89 } | |
90 | |
91 Error MemFsNode::Resize(off_t new_length) { | |
92 if (new_length < 0) | |
93 return EINVAL; | |
94 size_t new_size = static_cast<size_t>(new_length); | |
95 | |
96 if (new_size > data_capacity_) { | |
97 // While the node size is small, grow exponentially. When it starts to get | |
98 // larger, grow linearly. | |
99 size_t extra = std::min(new_size, kMaxResizeIncrement); | |
100 data_capacity_ = new_size + extra; | |
101 } else { | |
102 data_capacity_ = new_size; | |
103 } | |
104 | |
105 data_ = (char*)realloc(data_, data_capacity_); | |
106 if (data_capacity_ != 0) { | |
107 assert(data_ != NULL); | |
108 if (data_ == NULL) | |
109 return ENOMEM; | |
110 if (new_length > stat_.st_size) | |
111 memset(data_ + stat_.st_size, 0, new_length - stat_.st_size); | |
112 } | |
113 | |
114 stat_.st_size = new_length; | |
77 return 0; | 115 return 0; |
78 } | 116 } |
79 | 117 |
80 void MemFsNode::Resize(off_t new_size) { | |
81 if (new_size > static_cast<off_t>(data_.capacity())) { | |
82 // While the node size is small, grow exponentially. When it starts to get | |
83 // larger, grow linearly. | |
84 size_t extra = std::min<size_t>(new_size, kMaxResizeIncrement); | |
85 data_.reserve(new_size + extra); | |
86 } else if (new_size < stat_.st_size) { | |
87 // Shrink to fit. std::vector usually doesn't reduce allocation size, so | |
88 // use the swap trick. | |
89 std::vector<char>(data_).swap(data_); | |
90 } | |
91 data_.resize(new_size); | |
92 stat_.st_size = new_size; | |
93 } | |
94 | |
95 } // namespace nacl_io | 118 } // namespace nacl_io |
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