Mercurial > projects > dynamin
annotate dynamin/core/global.d @ 2:fab13ec910ba
Speed up toRomanNumerals() by removing heap allocations. Much faster for Tango's debug build.
| author | Jordan Miner <jminer7@gmail.com> |
|---|---|
| date | Mon, 15 Jun 2009 22:17:26 -0500 |
| parents | aa4efef0f0b1 |
| children | d806edad4300 |
| rev | line source |
|---|---|
| 0 | 1 // Written in the D programming language |
| 2 // www.digitalmars.com/d/ | |
| 3 | |
| 4 /* | |
| 5 * The contents of this file are subject to the Mozilla Public License Version | |
| 6 * 1.1 (the "License"); you may not use this file except in compliance with | |
| 7 * the License. You may obtain a copy of the License at | |
| 8 * http://www.mozilla.org/MPL/ | |
| 9 * | |
| 10 * Software distributed under the License is distributed on an "AS IS" basis, | |
| 11 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License | |
| 12 * for the specific language governing rights and limitations under the | |
| 13 * License. | |
| 14 * | |
| 15 * The Original Code is the Dynamin library. | |
| 16 * | |
| 17 * The Initial Developer of the Original Code is Jordan Miner. | |
| 18 * Portions created by the Initial Developer are Copyright (C) 2006-2009 | |
| 19 * the Initial Developer. All Rights Reserved. | |
| 20 * | |
| 21 * Contributor(s): | |
| 22 * Jordan Miner <jminer7@gmail.com> | |
| 23 * | |
| 24 */ | |
| 25 | |
| 26 module dynamin.core.global; | |
| 27 | |
| 28 import dynamin.core.string; | |
| 29 import tango.math.Math; | |
| 30 import tango.io.model.IFile; | |
| 31 import tango.core.Exception; | |
| 32 | |
| 33 public import tango.util.Convert; | |
| 34 | |
| 35 static if((void*).sizeof == 4) { | |
| 36 /** | |
| 37 * Defined as an int on 32-bit platforms and as a long on 64-bit platforms. | |
| 38 */ | |
| 39 alias int word; | |
| 40 /** | |
| 41 * Defined as a uint on 32-bit platforms and | |
| 42 * as a ulong on 64-bit platforms. | |
| 43 */ | |
| 44 alias uint uword; | |
| 45 } else static if((void*).sizeof == 8) { | |
| 46 /** | |
| 47 * Defined as an int on 32-bit platforms and as a long on 64-bit platforms. | |
| 48 */ | |
| 49 alias long word; | |
| 50 /** | |
| 51 * Defined as a uint on 32-bit platforms and | |
| 52 * as a ulong on 64-bit platforms. | |
| 53 */ | |
| 54 alias ulong uword; | |
| 55 } | |
| 56 | |
| 57 /** | |
| 58 * The string used to separate lines. | |
| 59 * This is "\r\n" under Windows and "\n" under Linux. | |
| 60 */ | |
| 61 const string LineSeparator = FileConst.NewlineString; | |
| 62 /** | |
| 63 * The string used to separate directories in a path. | |
| 64 * This is "\\" under Windows and "/" under Linux. | |
| 65 */ | |
| 66 const string DirSeparator = FileConst.PathSeparatorString; | |
| 67 /// | |
| 68 const char DirSeparatorChar = FileConst.PathSeparatorChar; | |
| 69 /** | |
| 70 * The string used to separate paths. | |
| 71 * This is ";" under Windows and ":" under Linux | |
| 72 */ | |
| 73 const string PathSeparator = FileConst.SystemPathString; | |
| 74 /// | |
| 75 const char PathSeparatorChar = FileConst.SystemPathChar; | |
| 76 | |
| 77 /** | |
| 78 * Tests whether num1 and num2 are equal. They are considered equal | |
| 79 * if the difference between them is less than epsilon. | |
| 80 * Examples: | |
| 81 * ----- | |
| 82 * floatsEqual(3.14, 3.2, 0.1) == true | |
| 83 * floatsEqual(3.14, 3.3, 0.1) == false | |
| 84 * floatsEqual(3.14, 3.151, 0.01) == false | |
| 85 * ----- | |
| 86 */ | |
| 87 bool floatsEqual(real num1, real num2, real epsilon) { | |
| 88 return abs(num1 - num2) <= epsilon; | |
| 89 } | |
| 90 unittest { | |
| 91 assert(floatsEqual(3.14, 3.2, 0.1) == true); | |
| 92 assert(floatsEqual(3.14, 3.3, 0.1) == false); | |
| 93 assert(floatsEqual(3.14, 3.151, 0.01) == false); | |
| 94 } | |
| 95 | |
| 96 /** | |
| 97 * Copies length elements starting at srcStart in srcData to destStart | |
| 98 * in destData. Data is copied as if srcData and destData are two separate | |
| 99 * arrays, even if they are the same. | |
| 100 */ | |
| 101 void arrayCopy(T)(T[] srcData, uint srcStart, T[] destData, uint destStart, uint length) { | |
| 102 if((srcData is destData && srcStart == destStart) || length == 0) | |
| 103 return; | |
| 104 if(srcStart > destStart) { | |
| 105 //copy forward | |
| 106 for(int i = 0; i < length; ++i) | |
| 107 destData[destStart + i] = srcData[srcStart + i]; | |
| 108 } else { | |
| 109 //copy reverse | |
| 110 for(int i = length-1; i >= 0; --i) | |
| 111 destData[destStart + i] = srcData[srcStart + i]; | |
| 112 } | |
| 113 } | |
| 114 unittest { | |
| 115 char[] c = "Computer".dup; | |
| 116 arrayCopy!(char)(c, 3, c, 2, 4); | |
| 117 assert(c == "Coputeer"); | |
| 118 c = "Computer".dup; | |
| 119 arrayCopy!(char)(c, 2, c, 3, 4); | |
| 120 assert(c == "Commputr"); | |
| 121 c = "hi".dup; | |
| 122 arrayCopy!(char)(c, 1, c, 0, 1); | |
| 123 assert(c == "ii"); | |
| 124 } | |
| 125 | |
| 126 /** | |
| 127 * Sets every byte of the specified memory block to value. | |
| 128 */ | |
| 129 void memoryFill(void* mem, uword count, ubyte value) { | |
| 130 ubyte* memB = cast(ubyte*)mem; | |
| 131 while(count != 0) { | |
| 132 *memB++ = value; | |
| 133 --count; | |
| 134 } | |
| 135 } | |
| 136 unittest { | |
| 137 char[] buff = "jEdit".dup; | |
| 138 memoryFill(buff.ptr+1, 3, 0x23); | |
| 139 assert(buff == "j\x23\x23\x23t"); | |
| 140 } | |
| 141 | |
| 142 /** | |
| 143 * Sets every byte of the specified memory block to zero. | |
| 144 */ | |
| 145 void memoryZero(void* mem, uword count) { | |
| 146 memoryFill(mem, count, 0); | |
| 147 } | |
| 148 unittest { | |
| 149 char[] buff = "jEdit".dup; | |
| 150 memoryZero(buff.ptr+1, 3); | |
| 151 assert(buff == "j\0\0\0t"); | |
| 152 } | |
| 153 | |
| 154 /** | |
| 155 * Copies the specified number of bytes from srcMem to destMem. The source | |
| 156 * and destination should not overlap, or the results will be undefined. | |
| 157 * Note that the source and destination parameters are opposite in | |
| 158 * order from the C function memcpy(). If count is a multiple of the | |
| 159 * native pointer size, the copy will be done in blocks of that size. | |
| 160 */ | |
| 161 void memoryCopy(void* srcMem, void* destMem, uword count) { | |
| 162 // copy in blocks of the pointer size, if possible | |
| 163 if(count % word.sizeof == 0) { | |
| 164 count /= word.sizeof; | |
| 165 uword* src = cast(uword*)srcMem; | |
| 166 uword* dest = cast(uword*)destMem; | |
| 167 while(count != 0) { | |
| 168 *dest++ = *src++; | |
| 169 --count; | |
| 170 } | |
| 171 } else { | |
| 172 ubyte* src = cast(ubyte*)srcMem; | |
| 173 ubyte* dest = cast(ubyte*)destMem; | |
| 174 while(count != 0) { | |
| 175 *dest++ = *src++; | |
| 176 --count; | |
| 177 } | |
| 178 } | |
| 179 } | |
| 180 unittest { | |
| 181 char[] buff = "Hello".dup; | |
| 182 memoryCopy(buff.ptr, buff.ptr+3, 2); | |
| 183 assert(buff == "HelHe"); | |
| 184 buff = "Longer text here".dup; | |
| 185 memoryCopy(buff.ptr+7, buff.ptr+12, 4); | |
| 186 assert(buff == "Longer text text"); | |
| 187 } | |
| 188 | |
| 189 /** | |
| 190 * Converts a number into its roman numeral form. The number must | |
| 191 * be between 0 and 3,999, inclusive. | |
| 192 * Examples: | |
| 193 * ----- | |
| 194 * toRomanNumerals(2) == "II" | |
| 195 * toRomanNumerals(58) == "LVIII" | |
| 196 * toRomanNumerals(194) == "CXCIV" | |
| 197 * ----- | |
| 198 */ | |
| 199 string toRomanNumerals(int num) { | |
| 200 if(num > 3999 || num < 0) | |
| 201 throw new IllegalArgumentException("ToRomanNumerals():" ~ | |
| 202 "highest convertable roman numeral is 3999"); | |
|
2
fab13ec910ba
Speed up toRomanNumerals() by removing heap allocations. Much faster for Tango's debug build.
Jordan Miner <jminer7@gmail.com>
parents:
0
diff
changeset
|
203 static combos = [[0][0..0], [0], [0,0], [0,0,0], [0,1], |
| 0 | 204 [1], [1,0], [1,0,0], [1,0,0,0], [0,2]]; |
|
2
fab13ec910ba
Speed up toRomanNumerals() by removing heap allocations. Much faster for Tango's debug build.
Jordan Miner <jminer7@gmail.com>
parents:
0
diff
changeset
|
205 static letters = ['I', 'V', 'X', 'L', 'C', 'D', 'M']; |
| 0 | 206 string str = ""; |
| 207 int letterOffset = 0; | |
| 208 while(num > 0) { | |
| 209 foreach_reverse(int c; combos[num % 10]) | |
| 210 str = letters[c+letterOffset] ~ str; | |
| 211 num /= 10; | |
| 212 letterOffset += 2; | |
| 213 } | |
| 214 return str; | |
| 215 } | |
| 216 unittest { | |
| 217 assert(toRomanNumerals(2) == "II"); | |
| 218 assert(toRomanNumerals(58) == "LVIII"); | |
| 219 assert(toRomanNumerals(194) == "CXCIV"); | |
| 220 | |
| 221 assert(toRomanNumerals(0) == ""); | |
| 222 assert(toRomanNumerals(1) == "I"); | |
| 223 assert(toRomanNumerals(10) == "X"); | |
| 224 assert(toRomanNumerals(500) == "D"); | |
| 225 assert(toRomanNumerals(18) == "XVIII"); | |
| 226 assert(toRomanNumerals(3949) == "MMMCMXLIX"); | |
| 227 } | |
| 228 | |
| 229 int numeralToValue(char c) { | |
| 230 switch(c) { | |
| 231 case 'I': case 'i': return 1; | |
| 232 case 'V': case 'v': return 5; | |
| 233 case 'X': case 'x': return 10; | |
| 234 case 'L': case 'l': return 50; | |
| 235 case 'C': case 'c': return 100; | |
| 236 case 'D': case 'd': return 500; | |
| 237 case 'M': case 'm': return 1000; | |
| 238 default: return -1; | |
| 239 } | |
| 240 } | |
| 241 /** | |
| 242 * Parses the specified string of roman numerals and returns the value. | |
| 243 * The value must be less than or equal to 3,999. The string may be uppercase, | |
| 244 * lowercase, or a mixture of both cases. | |
| 245 * Examples: | |
| 246 * ----- | |
| 247 * parseRomanNumerals("II") == 2 | |
| 248 * parseRomanNumerals("LVIII") == 58 | |
| 249 * parseRomanNumerals("CXCIV") == 194 | |
| 250 * parseRomanNumerals("xxxxviiii") == 49 | |
| 251 * ----- | |
| 252 */ | |
| 253 int parseRomanNumerals(string str) { | |
| 254 int num = 0; | |
| 255 int largestSoFar = 1; | |
| 256 foreach_reverse(c; str) { | |
| 257 int value = numeralToValue(c); | |
| 258 if(value == -1) | |
| 259 throw new IllegalArgumentException("Invalid roman numeral: " ~ c); | |
| 260 if(value < largestSoFar) { | |
| 261 num -= value; | |
| 262 } else { | |
| 263 num += value; | |
| 264 largestSoFar = value; | |
| 265 } | |
| 266 } | |
| 267 if(num > 3999 || num < 0) | |
| 268 throw new IllegalArgumentException("ParseRomanNumerals():" ~ | |
| 269 "highest convertable roman numeral is 3999"); | |
| 270 return num; | |
| 271 } | |
| 272 unittest { | |
| 273 assert(parseRomanNumerals("II") == 2); | |
| 274 assert(parseRomanNumerals("LVIII") == 58); | |
| 275 assert(parseRomanNumerals("CXCIV") == 194); | |
| 276 assert(parseRomanNumerals("xxxxviiii") == 49); | |
| 277 | |
| 278 assert(parseRomanNumerals("") == 0); | |
| 279 assert(parseRomanNumerals("I") == 1); | |
| 280 assert(parseRomanNumerals("X") == 10); | |
| 281 assert(parseRomanNumerals("D") == 500); | |
| 282 assert(parseRomanNumerals("XVIII") == 18); | |
| 283 assert(parseRomanNumerals("MMMCMXLIX") == 3949); | |
| 284 } | |
| 285 unittest { | |
| 286 for(int i = 0; i < 4000; ++i) | |
| 287 assert(toRomanNumerals(i).parseRomanNumerals() == i); | |
| 288 } | |
| 289 | |
| 290 /** | |
| 291 * Converts a number of bytes into a human friendly string. The units | |
| 292 * supported are bytes, KB, MB, GB, TB, PB, EB, ZB, and YB. | |
| 293 * Examples: | |
| 294 * ----- | |
| 295 * byteCountToString(202) == "202 bytes" | |
| 296 * byteCountToString(1021) == "1021 bytes" | |
| 297 * byteCountToString(106_496) == "104 KB" | |
| 298 * byteCountToString(620_705_792) == "591 MB" | |
| 299 * ----- | |
| 300 */ | |
| 301 string byteCountToString(ulong num) { | |
| 302 const factor = 1024; | |
| 303 //kilo, mega, giga, tera, peta, exa, zetta, yotta | |
| 304 char[][] units = [ | |
| 305 " bytes", " KB", " MB", " GB", " TB", " PB", " EB", " ZB", " YB"]; | |
| 306 uint unitIndex = 0; | |
| 307 ulong div = factor; | |
| 308 uint rem; | |
| 309 while(num > factor-1 && unitIndex < units.length-1) { | |
| 310 rem = num % factor; | |
| 311 num /= factor; | |
| 312 ++unitIndex; | |
| 313 } | |
| 314 //rem/1024 equals the fraction of unit | |
| 315 string str = to!(string)(num); | |
| 316 if(str.length < 3) { | |
| 317 str ~= "." ~ to!(string)(rem*10/factor); | |
| 318 } | |
| 319 str ~= units[unitIndex]; | |
| 320 return str; | |
| 321 } | |
| 322 unittest { | |
| 323 assert(byteCountToString(202) == "202 bytes"); | |
| 324 assert(byteCountToString(1021) == "1021 bytes"); | |
| 325 assert(byteCountToString(106_496) == "104 KB"); | |
| 326 assert(byteCountToString(620_705_792) == "591 MB"); | |
| 327 } | |
| 328 |