summaryrefslogtreecommitdiff
path: root/src/smalloc.h
blob: 835ebe1842c938830110d3f0542df9c34261487d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

#ifndef SRC_SMALLOC_H_
#define SRC_SMALLOC_H_

#include "node.h"
#include "v8.h"

namespace node {

// Forward declaration
class Environment;

/**
 * Simple memory allocator.
 *
 * Utilities for external memory allocation management. Is an abstraction for
 * v8's external array data handling to simplify and centralize how this is
 * managed.
 */
namespace smalloc {

// mirrors deps/v8/src/objects.h
static const unsigned int kMaxLength = 0x3fffffff;

NODE_EXTERN typedef void (*FreeCallback)(char* data, void* hint);

/**
 * Return byte size of external array type.
 */
NODE_EXTERN size_t ExternalArraySize(enum v8::ExternalArrayType type);

/**
 * Allocate external array data onto obj.
 *
 * Passed data transfers ownership, and if no callback is passed then memory
 * will automatically be free'd using free() (not delete[]).
 *
 * length is always the byte size of the data. Not the length of the external
 * array. This intentionally differs from the JS API so users always know
 * exactly how much memory is being allocated, regardless of the external array
 * type. For this reason the helper function ExternalArraySize is provided to
 * help determine the appropriate byte size to be allocated.
 *
 * In the following example we're allocating a Float array and setting the
 * "length" property on the Object:
 *
 * \code
 *    size_t array_length = 8;
 *    size_t byte_length = node::smalloc::ExternalArraySize(
 *        v8::kExternalFloatArray);
 *    v8::Local<v8::Object> obj = v8::Object::New();
 *    char* data = static_cast<char*>(malloc(byte_length * array_length));
 *    node::smalloc::Alloc(isolate, obj, data, byte_length,
 *                         v8::kExternalFloatArray);
 *    obj->Set(v8::String::NewFromUtf8("length"),
 *             v8::Integer::NewFromUnsigned(array_length));
 * \code
 */
NODE_EXTERN void Alloc(v8::Isolate* isolate,
                       v8::Handle<v8::Object> obj,
                       size_t length,
                       enum v8::ExternalArrayType type =
                       v8::kExternalUnsignedByteArray);
NODE_EXTERN void Alloc(v8::Isolate* isolate,
                       v8::Handle<v8::Object> obj,
                       char* data,
                       size_t length,
                       enum v8::ExternalArrayType type =
                       v8::kExternalUnsignedByteArray);
NODE_EXTERN void Alloc(v8::Isolate* isolate,
                       v8::Handle<v8::Object> obj,
                       size_t length,
                       FreeCallback fn,
                       void* hint,
                       enum v8::ExternalArrayType type =
                       v8::kExternalUnsignedByteArray);
NODE_EXTERN void Alloc(v8::Isolate* isolate,
                       v8::Handle<v8::Object> obj,
                       char* data,
                       size_t length,
                       FreeCallback fn,
                       void* hint,
                       enum v8::ExternalArrayType type =
                       v8::kExternalUnsignedByteArray);

/**
 * Free memory associated with an externally allocated object. If no external
 * memory is allocated to the object then nothing will happen.
 */
NODE_EXTERN void AllocDispose(v8::Isolate* isolate, v8::Handle<v8::Object> obj);


/**
 * Check if the Object has externally allocated memory.
 */
NODE_EXTERN bool HasExternalData(v8::Isolate* isolate,
                                 v8::Local<v8::Object> obj);


// Internal use
void Alloc(Environment* env,
           v8::Handle<v8::Object> obj,
           size_t length,
           enum v8::ExternalArrayType type =
           v8::kExternalUnsignedByteArray);
void Alloc(Environment* env,
           v8::Handle<v8::Object> obj,
           char* data,
           size_t length,
           enum v8::ExternalArrayType type =
           v8::kExternalUnsignedByteArray);
void Alloc(Environment* env,
           v8::Handle<v8::Object> obj,
           size_t length,
           FreeCallback fn,
           void* hint,
           enum v8::ExternalArrayType type =
           v8::kExternalUnsignedByteArray);
void Alloc(Environment* env,
           v8::Handle<v8::Object> obj,
           char* data,
           size_t length,
           FreeCallback fn,
           void* hint,
           enum v8::ExternalArrayType type =
           v8::kExternalUnsignedByteArray);
void AllocDispose(Environment* env, v8::Handle<v8::Object> obj);
bool HasExternalData(Environment* env, v8::Local<v8::Object> obj);

}  // namespace smalloc
}  // namespace node

#endif  // SRC_SMALLOC_H_