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1.1 root 1: /*
2: * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
3: *
4: * @APPLE_LICENSE_HEADER_START@
5: *
6: * The contents of this file constitute Original Code as defined in and
7: * are subject to the Apple Public Source License Version 1.1 (the
8: * "License"). You may not use this file except in compliance with the
9: * License. Please obtain a copy of the License at
10: * http://www.apple.com/publicsource and read it before using this file.
11: *
12: * This Original Code and all software distributed under the License are
13: * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
14: * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15: * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
16: * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
17: * License for the specific language governing rights and limitations
18: * under the License.
19: *
20: * @APPLE_LICENSE_HEADER_END@
21: */
22: #ifndef _IOBUFFERMEMORYDESCRIPTOR_H
23: #define _IOBUFFERMEMORYDESCRIPTOR_H
24:
25: #include <IOKit/IOMemoryDescriptor.h>
26:
27: class IOBufferMemoryDescriptor : public IOGeneralMemoryDescriptor
28: {
29: OSDeclareDefaultStructors(IOBufferMemoryDescriptor);
30:
31: protected:
32: void * _buffer;
33: vm_size_t _capacity;
34: bool _contiguous;
35: IOPhysicalAddress * _physAddrs;
36: unsigned _physSegCount;
37:
38: virtual void free();
39:
40: IOGeneralMemoryDescriptor::initWithAddress; /* not supported in subclass */
41: IOGeneralMemoryDescriptor::withAddress; /* not supported in subclass */
42: IOGeneralMemoryDescriptor::initWithRanges; /* not supported in subclass */
43: IOGeneralMemoryDescriptor::withRanges; /* not supported in subclass */
44:
45: public:
46:
47: /*
48: * initWithCapacity:
49: *
50: * Initialize a new IOBufferMemoryDescriptor with a buffer large enough to
51: * hold capacity bytes. The descriptor's length is initially set to zero.
52: */
53: virtual bool initWithCapacity(vm_size_t capacity,
54: IODirection withDirection,
55: bool withContiguousMemory = false);
56:
57: /*
58: * withCapacity:
59: *
60: * Returns a new IOBufferMemoryDescriptor with a buffer large enough to
61: * hold capacity bytes. The descriptor's length is initially set to zero.
62: */
63: static IOBufferMemoryDescriptor * withCapacity(
64: vm_size_t capacity,
65: IODirection withDirection,
66: bool withContiguousMemory = false);
67: /*
68: * initWithBytes:
69: *
70: * Initialize a new IOBufferMemoryDescriptor preloaded with bytes (copied).
71: * The descriptor's length and capacity are set to the input buffer's size.
72: */
73: virtual bool initWithBytes(const void * bytes,
74: vm_size_t withLength,
75: IODirection withDirection,
76: bool withContiguousMemory = false);
77:
78: /*
79: * withBytes:
80: *
81: * Returns a new IOBufferMemoryDescriptor preloaded with bytes (copied).
82: * The descriptor's length and capacity are set to the input buffer's size.
83: */
84: static IOBufferMemoryDescriptor * withBytes(
85: const void * bytes,
86: vm_size_t withLength,
87: IODirection withDirection,
88: bool withContiguousMemory = false);
89:
90: /*
91: * setLength:
92: *
93: * Change the buffer length of the memory descriptor. When a new buffer is
94: * created with initWithBytes, the descriptor's length is set to capacity,
95: * or its length is initially zero. This method allows one to resize the
96: * buffer length up to capacity or less. This eliminates the need to
97: * destroy and create new buffers when different sizes are needed. The
98: * descriptor position is implicitly reset to zero as a result of this call.
99: */
100: virtual void setLength(vm_size_t length);
101:
102: /*
103: * setDirection:
104: *
105: * Change the direction of the transfer. This method allows one to redirect
106: * the descriptor's transfer direction. This eliminates the need to destroy
107: * and create new buffers when different transfer directions are needed.
108: */
109: virtual void setDirection(IODirection direction);
110:
111: /*
112: * getCapacity:
113: *
114: * Get the buffer capacity
115: */
116: virtual vm_size_t getCapacity() const;
117:
118: /*
119: * getBytesNoCopy:
120: *
121: * Return the virtual address of the beginning of the buffer
122: */
123: virtual void *getBytesNoCopy();
124:
125: /*
126: * getBytesNoCopy:
127: *
128: * Return the virtual address of an offset from the beginning of the buffer
129: */
130: virtual void *getBytesNoCopy(vm_size_t start, vm_size_t withLength);
131:
132: /*
133: * appendBytes:
134: *
135: * Add some data to the end of the buffer. This method automatically
136: * maintains the memory descriptor buffer length. Note that appendBytes
137: * will not copy past the end of the memory descriptor's current capacity.
138: */
139: virtual bool appendBytes(const void *bytes, vm_size_t withLength);
140:
141: /*
142: * getPhysicalSegment:
143: *
144: * Get the physical address of the buffer, relative to the current position.
145: * If the current position is at the end of the buffer, a zero is returned.
146: */
147: virtual IOPhysicalAddress getPhysicalSegment(IOByteCount offset,
148: IOPhysicalLength * length);
149: };
150:
151: #endif /* !_IOBUFFERMEMORYDESCRIPTOR_H */
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