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vertexDataBuffer.I
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1/**
2 * PANDA 3D SOFTWARE
3 * Copyright (c) Carnegie Mellon University. All rights reserved.
4 *
5 * All use of this software is subject to the terms of the revised BSD
6 * license. You should have received a copy of this license along
7 * with this source code in a file named "LICENSE."
8 *
9 * @file vertexDataBuffer.I
10 * @author drose
11 * @date 2007-05-14
12 */
13
14/**
15 *
16 */
17INLINE VertexDataBuffer::
18VertexDataBuffer() :
19 _resident_data(nullptr),
20 _size(0),
21 _reserved_size(0)
22{
23}
24
25/**
26 *
27 */
28INLINE VertexDataBuffer::
29VertexDataBuffer(size_t size) :
30 _resident_data(nullptr),
31 _size(0),
32 _reserved_size(0)
33{
34 do_unclean_realloc(size);
35 _size = size;
36}
37
38/**
39 *
40 */
41INLINE VertexDataBuffer::
42VertexDataBuffer(const VertexDataBuffer &copy) :
43 _resident_data(nullptr),
44 _size(0),
45 _reserved_size(0)
46{
47 (*this) = copy;
48}
49
50/**
51 *
52 */
53INLINE VertexDataBuffer::
54~VertexDataBuffer() {
55 clear();
56}
57
58/**
59 * Returns a read-only pointer to the raw data, or NULL if the data is not
60 * currently resident. If the data is not currently resident, this will
61 * implicitly request it to become resident soon.
62 *
63 * If force is true, this method will never return NULL (unless the data is
64 * actually empty), but may block until the data is available.
65 */
66INLINE const unsigned char *VertexDataBuffer::
67 get_read_pointer(bool force) const {
68 LightMutexHolder holder(_lock);
69
70 const unsigned char *ptr;
71 if (_resident_data != nullptr || _size == 0) {
72 ptr = _resident_data;
73 } else {
74 nassertr(_block != nullptr, nullptr);
75 nassertr(_reserved_size >= _size, nullptr);
76
77 // We don't necessarily need to page the buffer all the way into independent
78 // status; it's sufficient just to return the block's pointer, which will
79 // force its page to resident status.
80 ptr = _block->get_pointer(force);
81 }
82#ifdef _DEBUG
83 assert(((uintptr_t)ptr % MEMORY_HOOK_ALIGNMENT) == 0);
84#endif
85 return (const unsigned char *)ASSUME_ALIGNED(ptr, MEMORY_HOOK_ALIGNMENT);
86}
87
88/**
89 * Returns a writable pointer to the raw data.
90 */
91INLINE unsigned char *VertexDataBuffer::
92 get_write_pointer() {
93 LightMutexHolder holder(_lock);
94
95 if (_resident_data == nullptr && _reserved_size != 0) {
96 do_page_in();
97 }
98 nassertr(_reserved_size >= _size, nullptr);
99#ifdef _DEBUG
100 assert(((uintptr_t)_resident_data % MEMORY_HOOK_ALIGNMENT) == 0);
101#endif
102 return (unsigned char *)ASSUME_ALIGNED(_resident_data, MEMORY_HOOK_ALIGNMENT);
103}
104
105/**
106 * Returns the number of bytes in the buffer.
107 */
108INLINE size_t VertexDataBuffer::
109 get_size() const {
110 return _size;
111}
112
113/**
114 * Returns the total number of bytes "reserved" in the buffer. This may be
115 * greater than or equal to get_size(). If it is greater, the additional
116 * bytes are extra unused bytes in the buffer, and this indicates the maximum
117 * value that may be passed to set_size() without first calling one of the
118 * realloc methods.
119 */
120INLINE size_t VertexDataBuffer::
121 get_reserved_size() const {
122 return _reserved_size;
123}
124
125/**
126 * Changes the size of the buffer. The new size must be less than or equal to
127 * the "reserved" size, which can only be changed via clean_realloc() or
128 * unclean_realloc().
129 */
130INLINE void VertexDataBuffer::
131 set_size(size_t size) {
132 LightMutexHolder holder(_lock);
133 nassertv(size <= _reserved_size);
134
135 if (size != _size) {
136 if (_resident_data == nullptr && _reserved_size != 0) {
137 do_page_in();
138 }
139
140 _size = size;
141 }
142}
143
144/**
145 * Changes the "reserved" size of the buffer, preserving its data (except for
146 * any data beyond the new end of the buffer, if the buffer is being reduced).
147 * If the buffer is expanded, the new data is uninitialized.
148 *
149 * It is an error to set the reserved size smaller than the size specified
150 * with set_size().
151 */
152INLINE void VertexDataBuffer::
153 clean_realloc(size_t reserved_size) {
154 LightMutexHolder holder(_lock);
155 do_clean_realloc(reserved_size);
156}
157
158/**
159 * Changes the size of the buffer, without regard to preserving its data. The
160 * buffer may contain random data after this call.
161 *
162 * It is an error to set the reserved size smaller than the size specified
163 * with set_size().
164 */
165INLINE void VertexDataBuffer::
166 unclean_realloc(size_t reserved_size) {
167 LightMutexHolder holder(_lock);
168 do_unclean_realloc(reserved_size);
169}
170
171/**
172 * Empties the buffer and sets its size to 0.
173 */
174INLINE void VertexDataBuffer::
175 clear() {
176 LightMutexHolder holder(_lock);
177 _size = 0;
178 do_unclean_realloc(0);
179}
180
181/**
182 * Moves the buffer out of independent memory and puts it on a page in the
183 * indicated book. The buffer may still be directly accessible as long as its
184 * page remains resident. Any subsequent attempt to rewrite the buffer will
185 * implicitly move it off of the page and back into independent memory.
186 */
187INLINE void VertexDataBuffer::
188 page_out(VertexDataBook &book) {
189 LightMutexHolder holder(_lock);
190 do_page_out(book);
191}
LightMutexHolder
Similar to MutexHolder, but for a light mutex.
Definition lightMutexHolder.h:25
VertexDataBook
A collection of VertexDataPages, which can be used to allocate new VertexDataBlock objects.
Definition vertexDataBook.h:30
VertexDataBuffer
A block of bytes that stores the actual raw vertex data referenced by a GeomVertexArrayData object.
Definition vertexDataBuffer.h:52
VertexDataBuffer::set_size
void set_size(size_t size)
Changes the size of the buffer.
Definition vertexDataBuffer.I:131
VertexDataBuffer::get_write_pointer
unsigned char * get_write_pointer()
Returns a writable pointer to the raw data.
Definition vertexDataBuffer.I:92
VertexDataBuffer::page_out
void page_out(VertexDataBook &book)
Moves the buffer out of independent memory and puts it on a page in the indicated book.
Definition vertexDataBuffer.I:188
VertexDataBuffer::get_read_pointer
const unsigned char * get_read_pointer(bool force) const
Returns a read-only pointer to the raw data, or NULL if the data is not currently resident.
Definition vertexDataBuffer.I:67
VertexDataBuffer::unclean_realloc
void unclean_realloc(size_t reserved_size)
Changes the size of the buffer, without regard to preserving its data.
Definition vertexDataBuffer.I:166
VertexDataBuffer::clear
void clear()
Empties the buffer and sets its size to 0.
Definition vertexDataBuffer.I:175
VertexDataBuffer::get_reserved_size
size_t get_reserved_size() const
Returns the total number of bytes "reserved" in the buffer.
Definition vertexDataBuffer.I:121
VertexDataBuffer::get_size
size_t get_size() const
Returns the number of bytes in the buffer.
Definition vertexDataBuffer.I:109
VertexDataBuffer::clean_realloc
void clean_realloc(size_t reserved_size)
Changes the "reserved" size of the buffer, preserving its data (except for any data beyond the new en...
Definition vertexDataBuffer.I:153