5 // Paolo Molaro (lupus@ximian.com)
6 // Dan Lewis (dihlewis@yahoo.co.uk)
8 // (C) 2001 Ximian, Inc. http://www.ximian.com
12 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
14 // Permission is hereby granted, free of charge, to any person obtaining
15 // a copy of this software and associated documentation files (the
16 // "Software"), to deal in the Software without restriction, including
17 // without limitation the rights to use, copy, modify, merge, publish,
18 // distribute, sublicense, and/or sell copies of the Software, and to
19 // permit persons to whom the Software is furnished to do so, subject to
20 // the following conditions:
22 // The above copyright notice and this permission notice shall be
23 // included in all copies or substantial portions of the Software.
25 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
26 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
27 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
28 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
29 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
30 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
31 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
34 using System.Runtime.CompilerServices;
35 using System.Runtime.InteropServices;
36 using System.Diagnostics.Contracts;
40 public static class Buffer {
42 public static int ByteLength (Array array)
44 // note: the other methods in this class also use ByteLength to test for
45 // null and non-primitive arguments as a side-effect.
48 throw new ArgumentNullException ("array");
50 int length = ByteLengthInternal (array);
52 throw new ArgumentException (Locale.GetText ("Object must be an array of primitives."));
57 public static byte GetByte (Array array, int index)
59 if (index < 0 || index >= ByteLength (array))
60 throw new ArgumentOutOfRangeException ("index", Locale.GetText(
61 "Value must be non-negative and less than the size of the collection."));
63 return GetByteInternal (array, index);
66 public static void SetByte (Array array, int index, byte value)
68 if (index < 0 || index >= ByteLength (array))
69 throw new ArgumentOutOfRangeException ("index", Locale.GetText(
70 "Value must be non-negative and less than the size of the collection."));
72 SetByteInternal (array, index, value);
75 public static void BlockCopy (Array src, int srcOffset, Array dst, int dstOffset, int count)
78 throw new ArgumentNullException ("src");
81 throw new ArgumentNullException ("dst");
84 throw new ArgumentOutOfRangeException ("srcOffset", Locale.GetText(
85 "Non-negative number required."));
88 throw new ArgumentOutOfRangeException ("dstOffset", Locale.GetText (
89 "Non-negative number required."));
92 throw new ArgumentOutOfRangeException ("count", Locale.GetText (
93 "Non-negative number required."));
95 // We do the checks in unmanaged code for performance reasons
96 bool res = BlockCopyInternal (src, srcOffset, dst, dstOffset, count);
98 // watch for integer overflow
99 if ((srcOffset > ByteLength (src) - count) || (dstOffset > ByteLength (dst) - count))
100 throw new ArgumentException (Locale.GetText (
101 "Offset and length were out of bounds for the array or count is greater than " +
102 "the number of elements from index to the end of the source collection."));
107 [MethodImplAttribute (MethodImplOptions.InternalCall)]
108 private extern static int ByteLengthInternal (Array array);
110 [MethodImplAttribute (MethodImplOptions.InternalCall)]
111 private extern static byte GetByteInternal (Array array, int index);
113 [MethodImplAttribute (MethodImplOptions.InternalCall)]
114 private extern static void SetByteInternal (Array array, int index, int value);
116 [MethodImplAttribute (MethodImplOptions.InternalCall)]
117 internal extern static bool BlockCopyInternal (Array src, int src_offset, Array dest, int dest_offset, int count);
119 internal static bool InternalBlockCopy (Array src, int src_offset, Array dest, int dest_offset, int count)
121 return BlockCopyInternal (src, src_offset, dest, dest_offset, count);
124 internal unsafe static void ZeroMemory (byte* src, long len)
130 internal unsafe static void Memcpy (byte* pDest, int destIndex, byte[] src, int srcIndex, int len)
132 Contract.Assert( (srcIndex >= 0) && (destIndex >= 0) && (len >= 0), "Index and length must be non-negative!");
133 Contract.Assert(src.Length - srcIndex >= len, "not enough bytes in src");
134 // If dest has 0 elements, the fixed statement will throw an
135 // IndexOutOfRangeException. Special-case 0-byte copies.
138 fixed(byte* pSrc = src) {
139 Memcpy(pDest + destIndex, pSrc + srcIndex, len);
143 internal unsafe static void Memcpy(byte[] dest, int destIndex, byte* src, int srcIndex, int len) {
144 Contract.Assert( (srcIndex >= 0) && (destIndex >= 0) && (len >= 0), "Index and length must be non-negative!");
145 Contract.Assert(dest.Length - destIndex >= len, "not enough bytes in dest");
146 // If dest has 0 elements, the fixed statement will throw an
147 // IndexOutOfRangeException. Special-case 0-byte copies.
150 fixed(byte* pDest = dest) {
151 Memcpy(pDest + destIndex, src + srcIndex, len);
155 internal static unsafe void memcpy4 (byte *dest, byte *src, int size) {
156 /*while (size >= 32) {
157 // using long is better than int and slower than double
158 // FIXME: enable this only on correct alignment or on platforms
159 // that can tolerate unaligned reads/writes of doubles
160 ((double*)dest) [0] = ((double*)src) [0];
161 ((double*)dest) [1] = ((double*)src) [1];
162 ((double*)dest) [2] = ((double*)src) [2];
163 ((double*)dest) [3] = ((double*)src) [3];
169 ((int*)dest) [0] = ((int*)src) [0];
170 ((int*)dest) [1] = ((int*)src) [1];
171 ((int*)dest) [2] = ((int*)src) [2];
172 ((int*)dest) [3] = ((int*)src) [3];
178 ((int*)dest) [0] = ((int*)src) [0];
184 ((byte*)dest) [0] = ((byte*)src) [0];
190 internal static unsafe void memcpy2 (byte *dest, byte *src, int size) {
192 ((short*)dest) [0] = ((short*)src) [0];
193 ((short*)dest) [1] = ((short*)src) [1];
194 ((short*)dest) [2] = ((short*)src) [2];
195 ((short*)dest) [3] = ((short*)src) [3];
201 ((short*)dest) [0] = ((short*)src) [0];
207 ((byte*)dest) [0] = ((byte*)src) [0];
209 static unsafe void memcpy1 (byte *dest, byte *src, int size) {
211 ((byte*)dest) [0] = ((byte*)src) [0];
212 ((byte*)dest) [1] = ((byte*)src) [1];
213 ((byte*)dest) [2] = ((byte*)src) [2];
214 ((byte*)dest) [3] = ((byte*)src) [3];
215 ((byte*)dest) [4] = ((byte*)src) [4];
216 ((byte*)dest) [5] = ((byte*)src) [5];
217 ((byte*)dest) [6] = ((byte*)src) [6];
218 ((byte*)dest) [7] = ((byte*)src) [7];
224 ((byte*)dest) [0] = ((byte*)src) [0];
225 ((byte*)dest) [1] = ((byte*)src) [1];
231 ((byte*)dest) [0] = ((byte*)src) [0];
234 internal static unsafe void Memcpy (byte *dest, byte *src, int size) {
235 // FIXME: if pointers are not aligned, try to align them
236 // so a faster routine can be used. Handle the case where
237 // the pointers can't be reduced to have the same alignment
238 // (just ignore the issue on x86?)
239 if ((((int)dest | (int)src) & 3) != 0) {
240 if (((int)dest & 1) != 0 && ((int)src & 1) != 0 && size >= 1) {
246 if (((int)dest & 2) != 0 && ((int)src & 2) != 0 && size >= 2) {
247 ((short*)dest) [0] = ((short*)src) [0];
252 if ((((int)dest | (int)src) & 1) != 0) {
253 memcpy1 (dest, src, size);
256 if ((((int)dest | (int)src) & 2) != 0) {
257 memcpy2 (dest, src, size);
261 memcpy4 (dest, src, size);
264 internal unsafe static int IndexOfByte(byte* src, byte value, int index, int count)
266 Contract.Assert(src != null, "src should not be null");
268 byte* pByte = src + index;
270 // Align up the pointer to sizeof(int).
271 while (((int)pByte & 3) != 0)
275 else if (*pByte == value)
276 return (int) (pByte - src);
282 // Fill comparer with value byte for comparisons
284 // comparer = 0/0/value/value
285 uint comparer = (((uint)value << 8) + (uint)value);
286 // comparer = value/value/value/value
287 comparer = (comparer << 16) + comparer;
289 // Run through buffer until we hit a 4-byte section which contains
290 // the byte we're looking for or until we exhaust the buffer.
293 // Test the buffer for presence of value. comparer contains the byte
294 // replicated 4 times.
295 uint t1 = *(uint*)pByte;
297 uint t2 = 0x7efefeff + t1;
298 t1 = t1 ^ 0xffffffff;
300 t1 = t1 & 0x81010100;
302 // if t1 is zero then these 4-bytes don't contain a match
305 // We've found a match for value, figure out which position it's in.
306 int foundIndex = (int) (pByte - src);
307 if (pByte[0] == value)
309 else if (pByte[1] == value)
310 return foundIndex + 1;
311 else if (pByte[2] == value)
312 return foundIndex + 2;
313 else if (pByte[3] == value)
314 return foundIndex + 3;
322 // Catch any bytes that might be left at the tail of the buffer
326 return (int) (pByte - src);
332 // If we don't have a match return -1;