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1 /*- |
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2 * Copyright (c) 2005 David Schultz <das@FreeBSD.ORG> |
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3 * All rights reserved. |
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4 * |
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5 * Redistribution and use in source and binary forms, with or without |
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6 * modification, are permitted provided that the following conditions |
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7 * are met: |
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8 * 1. Redistributions of source code must retain the above copyright |
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9 * notice, this list of conditions and the following disclaimer. |
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10 * 2. Redistributions in binary form must reproduce the above copyright |
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11 * notice, this list of conditions and the following disclaimer in the |
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12 * documentation and/or other materials provided with the distribution. |
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13 * |
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14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
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15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
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18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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24 * SUCH DAMAGE. |
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25 * © Portions copyright (c) 2005-2006 Nokia Corporation. All rights reserved. |
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26 */ |
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27 |
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28 #include <sys/cdefs.h> |
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29 #ifndef __SYMBIAN32__ |
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30 __FBSDID("$FreeBSD: src/lib/libc/string/strspn.c,v 1.5 2005/04/02 18:52:44 das Exp $"); |
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31 #endif |
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32 |
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33 #include <sys/types.h> |
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34 #include <limits.h> |
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35 #include <string.h> |
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36 |
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37 #define IDX(c) ((u_char)(c) / LONG_BIT) |
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38 #define BIT(c) ((u_long)1 << ((u_char)(c) % LONG_BIT)) |
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39 |
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40 EXPORT_C |
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41 size_t |
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42 strspn(const char *s, const char *charset) |
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43 { |
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44 /* |
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45 * NB: idx and bit are temporaries whose use causes gcc 3.4.2 to |
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46 * generate better code. Without them, gcc gets a little confused. |
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47 */ |
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48 const char *s1; |
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49 u_long bit; |
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50 u_long tbl[(UCHAR_MAX + 1) / LONG_BIT]; |
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51 int idx; |
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52 |
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53 if(*s == '\0') |
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54 return (0); |
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55 |
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56 #if LONG_BIT == 64 /* always better to unroll on 64-bit architectures */ |
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57 tbl[3] = tbl[2] = tbl[1] = tbl[0] = 0; |
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58 #else |
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59 for (idx = 0; idx < sizeof(tbl) / sizeof(tbl[0]); idx++) |
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60 tbl[idx] = 0; |
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61 #endif |
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62 for (; *charset != '\0'; charset++) { |
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63 idx = IDX(*charset); |
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64 bit = BIT(*charset); |
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65 tbl[idx] |= bit; |
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66 } |
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67 |
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68 for(s1 = s; ; s1++) { |
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69 idx = IDX(*s1); |
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70 bit = BIT(*s1); |
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71 if ((tbl[idx] & bit) == 0) |
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72 break; |
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73 } |
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74 return (s1 - s); |
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75 } |