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| 1 /* | |
| 2 * Copyright (C) 1996-2010, International Business Machines Corporation and Othe
rs. | |
| 3 * All rights reserved. | |
| 4 */ | |
| 5 | |
| 6 /** | |
| 7 * \file | |
| 8 * \brief C API: Boyer-Moore StringSearch prototype. | |
| 9 * \internal | |
| 10 */ | |
| 11 | |
| 12 #ifndef _BMS_H | |
| 13 #define _BMS_H | |
| 14 | |
| 15 #include "unicode/utypes.h" | |
| 16 | |
| 17 #if !UCONFIG_NO_COLLATION && !UCONFIG_NO_BREAK_ITERATION | |
| 18 | |
| 19 #include "unicode/ucol.h" | |
| 20 | |
| 21 /** | |
| 22 * A <code>UCD</code> object holds the Collator-specific data needed to | |
| 23 * compute the length of the shortest string that can | |
| 24 * generate a partcular list of CEs. | |
| 25 * | |
| 26 * <code>UCD</code> objects are quite expensive to compute. Because | |
| 27 * of this, they are cached. When you call <code>ucd_open</code> it | |
| 28 * returns a reference counted cached object. When you call <code>ucd_close</cod
e> | |
| 29 * the reference count on the object is decremented but the object is not delete
d. | |
| 30 * | |
| 31 * If you do not need to reuse any unreferenced objects in the cache, you can ca
ll | |
| 32 * <code>ucd_flushCCache</code>. If you no longer need any <code>UCD</code> | |
| 33 * objects, you can call <code>ucd_freeCache</code> | |
| 34 */ | |
| 35 typedef void UCD; | |
| 36 | |
| 37 /** | |
| 38 * Open a <code>UCD</code> object. | |
| 39 * | |
| 40 * @param coll - the collator | |
| 41 * @param status - will be set if any errors occur. | |
| 42 * | |
| 43 * @return the <code>UCD</code> object. You must call | |
| 44 * <code>ucd_close</code> when you are done using the object. | |
| 45 * | |
| 46 * Note: if on return status is set to an error, the only safe | |
| 47 * thing to do with the returned object is to call <code>ucd_close</code>. | |
| 48 * | |
| 49 * @internal ICU 4.0.1 technology preview | |
| 50 */ | |
| 51 U_CAPI UCD * U_EXPORT2 | |
| 52 ucd_open(UCollator *coll, UErrorCode *status); | |
| 53 | |
| 54 /** | |
| 55 * Release a <code>UCD</code> object. | |
| 56 * | |
| 57 * @param ucd - the object | |
| 58 * | |
| 59 * @internal ICU 4.0.1 technology preview | |
| 60 */ | |
| 61 U_CAPI void U_EXPORT2 | |
| 62 ucd_close(UCD *ucd); | |
| 63 | |
| 64 /** | |
| 65 * Get the <code>UCollator</code> object used to create a <code>UCD</code> objec
t. | |
| 66 * The <code>UCollator</code> object returned may not be the exact | |
| 67 * object that was used to create this object, but it will have the | |
| 68 * same behavior. | |
| 69 * | |
| 70 * @param ucd - the <code>UCD</code> object | |
| 71 * | |
| 72 * @return the <code>UCollator</code> used to create the given | |
| 73 * <code>UCD</code> object. | |
| 74 * | |
| 75 * @internal ICU 4.0.1 technology preview | |
| 76 */ | |
| 77 U_CAPI UCollator * U_EXPORT2 | |
| 78 ucd_getCollator(UCD *ucd); | |
| 79 | |
| 80 /** | |
| 81 * <code>UCD</code> objects are expensive to compute, and so | |
| 82 * may be cached. This routine will free the cached objects and delete | |
| 83 * the cache. | |
| 84 * | |
| 85 * WARNING: Don't call this until you are have called <code>close</code> | |
| 86 * for each <code>UCD</code> object that you have used. also, | |
| 87 * DO NOT call this if another thread may be calling <code>ucd_flushCache</code> | |
| 88 * at the same time. | |
| 89 * | |
| 90 * @internal ICU 4.0.1 technology preview | |
| 91 */ | |
| 92 U_CAPI void U_EXPORT2 | |
| 93 ucd_freeCache(); | |
| 94 | |
| 95 /** | |
| 96 * <code>UCD</code> objects are expensive to compute, and so | |
| 97 * may be cached. This routine will remove any unused <code>UCD</code> | |
| 98 * objects from the cache. | |
| 99 * | |
| 100 * @internal 4.0.1 technology preview | |
| 101 */ | |
| 102 U_CAPI void U_EXPORT2 | |
| 103 ucd_flushCache(); | |
| 104 | |
| 105 /** | |
| 106 * BMS | |
| 107 * | |
| 108 * This object holds the information needed to do a Collation sensitive Boyer-Mo
ore search. It encapulates | |
| 109 * the pattern, the "bad character" and "good suffix" tables, the Collator-based
data needed to compute them, | |
| 110 * and a reference to the text being searched. | |
| 111 * | |
| 112 * To do a search, you first need to get a <code>UCD</code> object by calling <c
ode>ucd_open</code>. | |
| 113 * Then you construct a <code>BMS</code> object from the <code>UCD</code> object
, the pattern | |
| 114 * string and the target string. Then you call the <code>search</code> method. H
ere's a code sample: | |
| 115 * | |
| 116 * <pre> | |
| 117 * void boyerMooreExample(UCollator *collator, UChar *pattern, int32_t patternLe
n, UChar *target, int32_t targetLength) | |
| 118 * { | |
| 119 * UErrorCode status = U_ZERO_ERROR; | |
| 120 * int32_t offset = 0, start = -1, end = -1; | |
| 121 * UCD *ucd = NULL); | |
| 122 * BMS *bms = NULL; | |
| 123 * | |
| 124 * ucd = ucd_open(collator, &status); | |
| 125 * if (U_FAILURE(status)) { | |
| 126 * // could not create a UCD object | |
| 127 * return; | |
| 128 * } | |
| 129 * | |
| 130 * BMS *bms = bms_open(ucd, pattern, patternLength, target, targetlength, &s
tatus); | |
| 131 * if (U_FAILURE(status)) { | |
| 132 * // could not create a BMS object | |
| 133 * ucd_close(ucd); | |
| 134 * return; | |
| 135 * } | |
| 136 * | |
| 137 * | |
| 138 * // Find all matches | |
| 139 * while (bms_search(bms, offset, &start, &end)) { | |
| 140 * // process the match between start and end | |
| 141 * ... | |
| 142 * | |
| 143 * // advance past the match | |
| 144 * offset = end; | |
| 145 * } | |
| 146 * | |
| 147 * // at this point, if offset == 0, there were no matches | |
| 148 * if (offset == 0) { | |
| 149 * // handle the case of no matches | |
| 150 * } | |
| 151 * | |
| 152 * bms_close(bms); | |
| 153 * ucd_close(ucd); | |
| 154 * | |
| 155 * // UCD objects are cached, so the call to | |
| 156 * // ucd_close doesn't delete the object. | |
| 157 * // Call this if you don't need the object any more. | |
| 158 * ucd_flushCache(); | |
| 159 * } | |
| 160 * </pre> | |
| 161 * | |
| 162 * NOTE: This is a technology preview. The final version of this API may not bea
r any resenblence to this API. | |
| 163 * | |
| 164 * Knows linitations: | |
| 165 * 1) Backwards searching has not been implemented. | |
| 166 * | |
| 167 * 2) For Han and Hangul characters, this code ignores any Collation tailoring
s. In general, | |
| 168 * this isn't a problem, but in Korean locals, at strength 1, Hangul charac
ters are tailored | |
| 169 * to be equal to Han characters with the same pronounciation. Because this
code ignroes | |
| 170 * tailorings, searching for a Hangul character will not find a Han charact
er and visa-versa. | |
| 171 * | |
| 172 * 3) In some cases, searching for a pattern that needs to be normalized and e
nds | |
| 173 * in a discontiguous contraction may fail. The only known cases of this ar
e with | |
| 174 * the Tibetan script. For example searching for the pattern | |
| 175 * "\u0F7F\u0F80\u0F81\u0F82\u0F83\u0F84\u0F85" will fail. (This case is ar
tificial. We've | |
| 176 * been unable to find a pratical, real-world example of this failure.) | |
| 177 * | |
| 178 * NOTE: This is a technology preview. The final version of this API may not bea
r any resenblence to this API. | |
| 179 * | |
| 180 * @internal ICU 4.0.1 technology preview | |
| 181 */ | |
| 182 struct BMS; | |
| 183 typedef struct BMS BMS; /**< @see BMS */ | |
| 184 | |
| 185 /** | |
| 186 * Construct a <code>MBS</code> object. | |
| 187 * | |
| 188 * @param ucd - A <code>UCD</code> object holding the Collator-sensitive data | |
| 189 * @param pattern - the string for which to search | |
| 190 * @param patternLength - the length of the string for which to search | |
| 191 * @param target - the string in which to search | |
| 192 * @param targetLength - the length of the string in which to search | |
| 193 * @param status - will be set if any errors occur. | |
| 194 * | |
| 195 * @return the <code>BMS</code> object. | |
| 196 * | |
| 197 * Note: if on return status is set to an error, the only safe | |
| 198 * thing to do with the returned object is to call | |
| 199 * <code>bms_close</code>. | |
| 200 * | |
| 201 * @internal ICU 4.0.1 technology preview | |
| 202 */ | |
| 203 U_CAPI BMS * U_EXPORT2 | |
| 204 bms_open(UCD *ucd, | |
| 205 const UChar *pattern, int32_t patternLength, | |
| 206 const UChar *target, int32_t targetLength, | |
| 207 UErrorCode *status); | |
| 208 | |
| 209 /** | |
| 210 * Close a <code>BMS</code> object and release all the | |
| 211 * storage associated with it. | |
| 212 * | |
| 213 * @param bms - the <code>BMS</code> object to close. | |
| 214 * @internal ICU 4.0.1 technology preview | |
| 215 */ | |
| 216 U_CAPI void U_EXPORT2 | |
| 217 bms_close(BMS *bms); | |
| 218 | |
| 219 /** | |
| 220 * Test the pattern to see if it generates any CEs. | |
| 221 * | |
| 222 * @param bms - the <code>BMS</code> object | |
| 223 * @return <code>TRUE</code> if the pattern string did not generate any CEs | |
| 224 * | |
| 225 * @internal ICU 4.0.1 technology preview | |
| 226 */ | |
| 227 U_CAPI UBool U_EXPORT2 | |
| 228 bms_empty(BMS *bms); | |
| 229 | |
| 230 /** | |
| 231 * Get the <code>UCD</code> object used to create | |
| 232 * a given <code>BMS</code> object. | |
| 233 * | |
| 234 * @param bms - the <code>BMS</code> object | |
| 235 * | |
| 236 * @return - the <code>UCD</code> object used to create | |
| 237 * the given <code>BMS</code> object. | |
| 238 * | |
| 239 * @internal ICU 4.0.1 technology preview | |
| 240 */ | |
| 241 U_CAPI UCD * U_EXPORT2 | |
| 242 bms_getData(BMS *bms); | |
| 243 | |
| 244 /** | |
| 245 * Search for the pattern string in the target string. | |
| 246 * | |
| 247 * @param bms - the <code>BMS</code> object | |
| 248 * @param offset - the offset in the target string at which to begin the search | |
| 249 * @param start - will be set to the starting offset of the match, or -1 if ther
e's no match | |
| 250 * @param end - will be set to the ending offset of the match, or -1 if there's
no match | |
| 251 * | |
| 252 * @return <code>TRUE</code> if the match succeeds, <code>FALSE</code> otherwise
. | |
| 253 * | |
| 254 * @internal ICU 4.0.1 technology preview | |
| 255 */ | |
| 256 U_CAPI UBool U_EXPORT2 | |
| 257 bms_search(BMS *bms, int32_t offset, int32_t *start, int32_t *end); | |
| 258 | |
| 259 /** | |
| 260 * Set the target string for the match. | |
| 261 * | |
| 262 * @param bms - the <code>BMS</code> object | |
| 263 * @param target - the new target string | |
| 264 * @param targetLength - the length of the new target string | |
| 265 * @param status - will be set if any errors occur. | |
| 266 * | |
| 267 * @internal ICU 4.0.1 technology preview | |
| 268 */ | |
| 269 U_CAPI void U_EXPORT2 | |
| 270 bms_setTargetString(BMS *bms, const UChar *target, int32_t targetLength, UErrorC
ode *status); | |
| 271 | |
| 272 #endif | |
| 273 | |
| 274 #endif /* _BMS_H */ | |
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Chromium Code Reviews
Issue 19417002:
Move ICU header part 2 (Closed)
Base URL: svn://chrome-svn/chrome/trunk/deps/third_party/icu46/