Emeric Vigier | 2f62582 | 2012-08-06 11:09:52 -0400 | [diff] [blame] | 1 | // Copyright (C) 1999-2005 Open Source Telecom Corporation. |
| 2 | // Copyright (C) 2006-2010 David Sugar, Tycho Softworks. |
| 3 | // |
| 4 | // This program is free software; you can redistribute it and/or modify |
| 5 | // it under the terms of the GNU General Public License as published by |
| 6 | // the Free Software Foundation; either version 2 of the License, or |
| 7 | // (at your option) any later version. |
| 8 | // |
| 9 | // This program is distributed in the hope that it will be useful, |
| 10 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | // GNU General Public License for more details. |
| 13 | // |
| 14 | // You should have received a copy of the GNU General Public License |
| 15 | // along with this program; if not, write to the Free Software |
| 16 | // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 17 | // |
| 18 | // As a special exception, you may use this file as part of a free software |
| 19 | // library without restriction. Specifically, if other files instantiate |
| 20 | // templates or use macros or inline functions from this file, or you compile |
| 21 | // this file and link it with other files to produce an executable, this |
| 22 | // file does not by itself cause the resulting executable to be covered by |
| 23 | // the GNU General Public License. This exception does not however |
| 24 | // invalidate any other reasons why the executable file might be covered by |
| 25 | // the GNU General Public License. |
| 26 | // |
| 27 | // This exception applies only to the code released under the name GNU |
| 28 | // Common C++. If you copy code from other releases into a copy of GNU |
| 29 | // Common C++, as the General Public License permits, the exception does |
| 30 | // not apply to the code that you add in this way. To avoid misleading |
| 31 | // anyone as to the status of such modified files, you must delete |
| 32 | // this exception notice from them. |
| 33 | // |
| 34 | // If you write modifications of your own for GNU Common C++, it is your choice |
| 35 | // whether to permit this exception to apply to your modifications. |
| 36 | // If you do not wish that, delete this exception notice. |
| 37 | // |
| 38 | |
| 39 | /** |
| 40 | * @file misc.h |
| 41 | * @short Memory management, configuration keydata objects and string |
| 42 | * tokenizer. |
| 43 | **/ |
| 44 | |
| 45 | #ifndef CCXX_MISC_H_ |
| 46 | #define CCXX_MISC_H_ |
| 47 | |
| 48 | #ifndef CCXX_MISSING_H_ |
| 49 | #include <cc++/missing.h> |
| 50 | #endif |
| 51 | |
| 52 | #ifndef CCXX_THREAD_H_ |
| 53 | #include <cc++/thread.h> |
| 54 | #endif |
| 55 | |
| 56 | #define KEYDATA_INDEX_SIZE 97 |
| 57 | #define KEYDATA_PAGER_SIZE 512 |
| 58 | |
| 59 | #if defined(PATH_MAX) |
| 60 | #if PATH_MAX > 512 |
| 61 | #define KEYDATA_PATH_SIZE 512 |
| 62 | #else |
| 63 | #define KEYDATA_PATH_SIZE PATH_MAX |
| 64 | #endif |
| 65 | #else |
| 66 | #define KEYDATA_PATH_SIZE 256 |
| 67 | #endif |
| 68 | |
| 69 | #ifdef CCXX_NAMESPACES |
| 70 | namespace ost { |
| 71 | #endif |
| 72 | |
| 73 | class __EXPORT Runlist; |
| 74 | class __EXPORT Runable; |
| 75 | |
| 76 | /** |
| 77 | * The memory pager is used to allocate cumulative memory pages for |
| 78 | * storing object specific "persistant" data that is presumed to persist |
| 79 | * during the life of a given derived object. When the object is |
| 80 | * destroyed, all accumulated data is automatically purged. |
| 81 | * |
| 82 | * There are a number of odd and specialized utility classes found in Common |
| 83 | * C++. The most common of these is the "MemPager" class. This is basically |
| 84 | * a class to enable page-grouped "cumulative" memory allocation; all |
| 85 | * accumulated allocations are dropped during the destructor. This class has |
| 86 | * found it's way in a lot of other utility classes in Common C++. |
| 87 | * |
| 88 | * @author David Sugar <dyfet@ostel.com> |
| 89 | * @short Accumulative object memory allocator. |
| 90 | */ |
| 91 | class __EXPORT MemPager |
| 92 | { |
| 93 | private: |
| 94 | friend class String; |
| 95 | friend class MemPagerObject; |
| 96 | |
| 97 | size_t pagesize; |
| 98 | unsigned int pages; |
| 99 | |
| 100 | struct _page { |
| 101 | struct _page *next; |
| 102 | size_t used; |
| 103 | } *page; |
| 104 | |
| 105 | protected: |
| 106 | /** |
| 107 | * Allocate first workspace from paged memory. This method |
| 108 | * scans all currently allocated blocks for available space |
| 109 | * before adding new pages and hence is both slower and more |
| 110 | * efficient. |
| 111 | * |
| 112 | * @param size size of memory to allocate. |
| 113 | * @return pointer to allocated memory. |
| 114 | */ |
| 115 | virtual void* first(size_t size); |
| 116 | |
| 117 | /** |
| 118 | * Allocate memory from either the currently active page, or |
| 119 | * allocate a new page for the object. |
| 120 | * |
| 121 | * @param size size of memory to allocate. |
| 122 | * @return pointer to allocated memory. |
| 123 | */ |
| 124 | virtual void* alloc(size_t size); |
| 125 | |
| 126 | /** |
| 127 | * Allocate a string from the memory pager pool and copy the |
| 128 | * string into it's new memory area. This method allocates |
| 129 | * memory by first searching for an available page, and then |
| 130 | * allocating a new page if no space is found. |
| 131 | * |
| 132 | * @param str string to allocate and copy into paged memory pool. |
| 133 | * @return copy of string from allocated memory. |
| 134 | */ |
| 135 | char* first(char *str); |
| 136 | |
| 137 | /** |
| 138 | * Allocate a string from the memory pager pool and copy the |
| 139 | * string inti it's new memory area. This checks only the |
| 140 | * last active page for available space before allocating a |
| 141 | * new page. |
| 142 | * |
| 143 | * @param str string to allocate and copy into paged memory pool. |
| 144 | * @return copy of string from allocated memory. |
| 145 | */ |
| 146 | char* alloc(const char *str); |
| 147 | |
| 148 | /** |
| 149 | * Create a paged memory pool for cumulative storage. This |
| 150 | * pool allocates memory in fixed "pagesize" chunks. Ideal |
| 151 | * performance is achived when the pool size matches the |
| 152 | * system page size. This pool can only exist in derived |
| 153 | * objects. |
| 154 | * |
| 155 | * @param pagesize page size to allocate chunks. |
| 156 | */ |
| 157 | MemPager(size_t pagesize = 4096); |
| 158 | |
| 159 | /** |
| 160 | * purge the current memory pool. |
| 161 | */ |
| 162 | void purge(void); |
| 163 | |
| 164 | /** |
| 165 | * Clean for memory cleanup before exiting. |
| 166 | */ |
| 167 | void clean(void); |
| 168 | |
| 169 | /** |
| 170 | * Delete the memory pool and all allocated memory. |
| 171 | */ |
| 172 | virtual ~MemPager(); |
| 173 | |
| 174 | public: |
| 175 | /** |
| 176 | * Return the total number of pages that have been allocated |
| 177 | * for this memory pool. |
| 178 | * |
| 179 | * @return number of pages allocated. |
| 180 | */ |
| 181 | inline int getPages(void) |
| 182 | {return pages;}; |
| 183 | }; |
| 184 | |
| 185 | /** |
| 186 | * The StackPager provides a repository to stash and retrieve working |
| 187 | * data in last-in-first-out order. The use of a mempager to support |
| 188 | * it's operation allows storage of arbitrary sized objects with no |
| 189 | * fixed limit. |
| 190 | * |
| 191 | * @author David Sugar <dyfet@ostel.com> |
| 192 | * @short last in first out object pager. |
| 193 | */ |
| 194 | class __EXPORT StackPager : protected MemPager |
| 195 | { |
| 196 | private: |
| 197 | typedef struct frame { |
| 198 | struct frame *next; |
| 199 | char data[1]; |
| 200 | } frame_t; |
| 201 | |
| 202 | frame_t *stack; |
| 203 | |
| 204 | public: |
| 205 | /** |
| 206 | * Create a lifo pager as a mempager. |
| 207 | * |
| 208 | * @param pagesize for memory allocation |
| 209 | */ |
| 210 | StackPager(size_t pagesize); |
| 211 | |
| 212 | /** |
| 213 | * Push an arbitrary object onto the stack. |
| 214 | * |
| 215 | * @return stack memory location. |
| 216 | * @param object pointer to data |
| 217 | * @param size of data. |
| 218 | */ |
| 219 | void *push(const void *object, size_t size); |
| 220 | |
| 221 | /** |
| 222 | * Push a string onto the stack. |
| 223 | * |
| 224 | * @return stack memory location. |
| 225 | * @param string pointer. |
| 226 | */ |
| 227 | void *push(const char *string); |
| 228 | |
| 229 | /** |
| 230 | * Retrieve next object from stack. |
| 231 | * |
| 232 | * @return object. |
| 233 | */ |
| 234 | void *pull(void); |
| 235 | |
| 236 | /** |
| 237 | * Purge the stack of all objects and memory allocations. |
| 238 | */ |
| 239 | void purge(void); |
| 240 | }; |
| 241 | |
| 242 | /** |
| 243 | * The shared mempager uses a mutex to protect key access methods. |
| 244 | * This class is used when a mempager will be shared by multiple |
| 245 | * threads. |
| 246 | * |
| 247 | * @author David Sugar <dyfet@ostel.com> |
| 248 | * @short mutex protected memory pager. |
| 249 | */ |
| 250 | class __EXPORT SharedMemPager : public MemPager, public Mutex |
| 251 | { |
| 252 | protected: |
| 253 | /** |
| 254 | * Create a mempager mutex pool. |
| 255 | * |
| 256 | * @param pagesize page size for allocation. |
| 257 | * @param name a name for the pool. |
| 258 | */ |
| 259 | SharedMemPager(size_t pagesize = 4096, const char *name = NULL); |
| 260 | |
| 261 | /** |
| 262 | * Purge the memory pool while locked. |
| 263 | */ |
| 264 | void purge(void); |
| 265 | |
| 266 | /** |
| 267 | * Get the first memory page after locking. |
| 268 | * |
| 269 | * @return allocated memory space. |
| 270 | * @param size of request. |
| 271 | */ |
| 272 | void* first(size_t size); |
| 273 | |
| 274 | /** |
| 275 | * Get the last memory page after locking. |
| 276 | * |
| 277 | * @return allocated memory space. |
| 278 | * @param size of request. |
| 279 | */ |
| 280 | void* alloc(size_t size); |
| 281 | }; |
| 282 | |
| 283 | __EXPORT void endKeydata(void); |
| 284 | |
| 285 | /** |
| 286 | * Keydata objects are used to load and hold "configuration" data for |
| 287 | * a given application. |
| 288 | * |
| 289 | * This class is used to load and then hold "<code>keyword = value</code>" pairs parsed from a text |
| 290 | * based "config" file that has been divided into "<code>[sections]</code>". The syntax is: |
| 291 | * |
| 292 | * <code><pre> |
| 293 | * [section_name] |
| 294 | * key1=value1 |
| 295 | * key2=value2</pre></code> |
| 296 | * |
| 297 | * Essentially, the "path" is a "keypath" into a theoretical namespace of key |
| 298 | * pairs, hence one does not use "real" filepaths that may be OS dependent. The "<code>/</code>" path refers |
| 299 | * to "<code>/etc</code>" prefixed (on UNIX) directories and this is processed within the constructor. It |
| 300 | * could refer to the <code>/config</code> prefix on QNX, or even, gasp, a "<code>C:\WINDOWS</code>". Hence, a keypath of |
| 301 | * "<code>/bayonne.d/vmhost/smtp</code>" actually resolves to a "<code>/etc/bayonne.d/vmhost.conf</code>" and loads key |
| 302 | * value pairs from the <code>[smtp]</code> section of that <code>.conf</code> file. |
| 303 | * |
| 304 | * Similarly, something like "<code>~bayonne/smtp</code>" path refers to a "<code>~/.bayonnerc</code>" and loads key pairs |
| 305 | * from the <code>[smtp]</code> section. This coercion occurs before the name is passed to the open call. |
| 306 | * |
| 307 | * I actually use derived keydata based classes as global initialized objects, and they hence |
| 308 | * automatically load and parse config file entries even before "main" has started. |
| 309 | * |
| 310 | * Keydata can hold multiple values for the same key pair. This can |
| 311 | * occur either from storing a "list" of data items in a config file, |
| 312 | * or when overlaying multiple config sources (such as <code>/etc/....conf</code> and |
| 313 | * <code>~/.confrc</code> segments) into a single object. The keys are stored as |
| 314 | * cumulative (read-only/replacable) config values under a hash index |
| 315 | * system for quick retrieval. |
| 316 | * |
| 317 | * Keydata can |
| 318 | * also load a table of "initialization" values for keyword pairs that were |
| 319 | * not found in the external file. |
| 320 | * |
| 321 | * One typically derives an application specific keydata class to load a |
| 322 | * specific portion of a known config file and initialize it's values. One |
| 323 | * can then declare a global instance of these objects and have |
| 324 | * configuration data initialized automatically as the executable is loaded. |
| 325 | * |
| 326 | * Hence, if I have a "[paths]" section in a "<code>/etc/server.conf?</code>" file, I might |
| 327 | * define something like: |
| 328 | * |
| 329 | * <code><pre> |
| 330 | * class KeyPaths : public Keydata |
| 331 | * { |
| 332 | * public: |
| 333 | * KeyPaths() : Keydata("/server/paths") |
| 334 | * { |
| 335 | * static Keydata::Define *defvalues = { |
| 336 | * {"datafiles", "/var/server"}, |
| 337 | * {NULL, NULL}}; |
| 338 | * |
| 339 | * // override with [paths] from "~/.serverrc" if avail. |
| 340 | * |
| 341 | * load("~server/paths"); |
| 342 | * load(defvalues); |
| 343 | * } |
| 344 | * }; |
| 345 | * |
| 346 | * KeyPaths keypaths; |
| 347 | * </pre></code> |
| 348 | * |
| 349 | * @author David Sugar <dyfet@ostel.com> |
| 350 | * @short load text configuration files into keyword pairs. |
| 351 | */ |
| 352 | class __EXPORT Keydata : protected MemPager |
| 353 | { |
| 354 | public: |
| 355 | #ifdef CCXX_PACKED |
| 356 | #pragma pack(1) |
| 357 | #endif |
| 358 | |
| 359 | struct Keyval { |
| 360 | Keyval *next; |
| 361 | char val[1]; |
| 362 | }; |
| 363 | |
| 364 | struct Keysym { |
| 365 | Keysym *next; |
| 366 | Keyval *data; |
| 367 | const char **list; |
| 368 | short count; |
| 369 | char sym[1]; |
| 370 | }; |
| 371 | |
| 372 | struct Define { |
| 373 | const char *keyword; |
| 374 | const char *value; |
| 375 | }; |
| 376 | |
| 377 | #ifdef CCXX_PACKED |
| 378 | #pragma pack() |
| 379 | #endif |
| 380 | |
| 381 | private: |
| 382 | static std::ifstream *cfgFile; |
| 383 | static char lastpath[KEYDATA_PATH_SIZE + 1]; |
| 384 | static int count; |
| 385 | static int sequence; |
| 386 | |
| 387 | int link; |
| 388 | |
| 389 | Keysym *keys[KEYDATA_INDEX_SIZE]; |
| 390 | |
| 391 | /** |
| 392 | * Compute a hash key signature id for a symbol name. |
| 393 | * |
| 394 | * @return key signature index path. |
| 395 | * @param sym symbol name. |
| 396 | */ |
| 397 | unsigned getIndex(const char *sym); |
| 398 | |
| 399 | protected: |
| 400 | Keysym* getSymbol(const char *sym, bool create); |
| 401 | |
| 402 | public: |
| 403 | /** |
| 404 | * Load additional key values into the currrent object from |
| 405 | * the specfied config source (a config file/section pair). |
| 406 | * These values will overlay the current keywords when matches |
| 407 | * are found. This can be used typically in a derived config |
| 408 | * object class constructor to first load a <code>/etc</code> section, and |
| 409 | * then load a matching user specific entry from <code>~/.</code> to override |
| 410 | * default system values with user specific keyword values. |
| 411 | * |
| 412 | * @param keypath (filepath/section) |
| 413 | */ |
| 414 | void load(const char *keypath); |
| 415 | |
| 416 | /** |
| 417 | * Load additional key values into the currrent object from |
| 418 | * the specfied config source (a config file/section pair). |
| 419 | * These values will overlay the current keywords when matches |
| 420 | * are found. This can be used typically in a derived config |
| 421 | * object class constructor to first load a <code>/etc</code> section, and |
| 422 | * then load a matching user specific entry from <code>~/.</code> to override |
| 423 | * default system values with user specific keyword values. |
| 424 | * This varient puts a prefix in front of the key name. |
| 425 | * |
| 426 | * @param prefix |
| 427 | * @param keypath (filepath/section) |
| 428 | */ |
| 429 | void loadPrefix(const char *prefix, const char *keypath); |
| 430 | |
| 431 | /** |
| 432 | * Load additional keys into the current object using a real |
| 433 | * filename that is directly passed rather than a computed key |
| 434 | * path. This also uses a [keys] section as passed to the object. |
| 435 | * |
| 436 | * @param filepath to load from |
| 437 | * @param keys section to parse from, or NULL to parse from head |
| 438 | * @param pre optional key prefix |
| 439 | */ |
| 440 | void loadFile(const char *filepath, const char *keys = NULL, const char *pre = NULL); |
| 441 | |
| 442 | /** |
| 443 | * Load default keywords into the current object. This only |
| 444 | * loads keyword entries which have not already been defined |
| 445 | * to reduce memory usage. This form of Load is also commonly |
| 446 | * used in the constructor of a derived Keydata class. |
| 447 | * |
| 448 | * @param pairs list of NULL terminated default keyword/value pairs. |
| 449 | */ |
| 450 | void load(Define *pairs); |
| 451 | |
| 452 | /** |
| 453 | * Create an empty key data object. |
| 454 | */ |
| 455 | Keydata(); |
| 456 | |
| 457 | /** |
| 458 | * Create a new key data object and use "Load" method to load an |
| 459 | * initial config file section into it. |
| 460 | * |
| 461 | * @param keypath (filepath/section) |
| 462 | * specifies the home path. |
| 463 | */ |
| 464 | Keydata(const char *keypath); |
| 465 | |
| 466 | /** |
| 467 | * Alternate constructor can take a define list and an optional |
| 468 | * pathfile to parse. |
| 469 | * |
| 470 | * @param pairs of keyword values from a define list |
| 471 | * @param keypath of optional file and section to load from |
| 472 | */ |
| 473 | Keydata(Define *pairs, const char *keypath = NULL); |
| 474 | |
| 475 | /** |
| 476 | * Destroy the keydata object and all allocated memory. This |
| 477 | * may also clear the "cache" file stream if no other keydata |
| 478 | * objects currently reference it. |
| 479 | */ |
| 480 | virtual ~Keydata(); |
| 481 | |
| 482 | /** |
| 483 | * Unlink the keydata object from the cache file stream. This |
| 484 | * should be used if you plan to keepa Keydata object after it |
| 485 | * is loaded once all keydata objects have been loaded, otherwise |
| 486 | * the cfgFile stream will remain open. You can also use |
| 487 | * endKeydata(). |
| 488 | */ |
| 489 | void unlink(void); |
| 490 | |
| 491 | /** |
| 492 | * Get a count of the number of data "values" that is associated |
| 493 | * with a specific keyword. Each value is from an accumulation of |
| 494 | * "<code>load()</code>" requests. |
| 495 | * |
| 496 | * @param sym keyword symbol name. |
| 497 | * @return count of values associated with keyword. |
| 498 | */ |
| 499 | int getCount(const char *sym); |
| 500 | |
| 501 | /** |
| 502 | * Get the first data value for a given keyword. This will |
| 503 | * typically be the <code>/etc</code> set global default. |
| 504 | * |
| 505 | * @param sym keyword symbol name. |
| 506 | * @return first set value for this symbol. |
| 507 | */ |
| 508 | const char* getFirst(const char *sym); |
| 509 | |
| 510 | /** |
| 511 | * Get the last (most recently set) value for a given keyword. |
| 512 | * This is typically the value actually used. |
| 513 | * |
| 514 | * @param sym keyword symbol name. |
| 515 | * @return last set value for this symbol. |
| 516 | */ |
| 517 | const char* getLast(const char *sym); |
| 518 | |
| 519 | /** |
| 520 | * Find if a given key exists. |
| 521 | * |
| 522 | * @param sym keyword to find. |
| 523 | * @return true if exists. |
| 524 | */ |
| 525 | bool isKey(const char *sym); |
| 526 | |
| 527 | /** |
| 528 | * Get a string value, with an optional default if missing. |
| 529 | * |
| 530 | * @param sym keyword name. |
| 531 | * @param default if not present. |
| 532 | * @return string value of key. |
| 533 | */ |
| 534 | const char *getString(const char *sym, const char *def = NULL); |
| 535 | |
| 536 | /** |
| 537 | * Get a long value, with an optional default if missing. |
| 538 | * |
| 539 | * @param sym keyword name. |
| 540 | * @param default if not present. |
| 541 | * @return long value of key. |
| 542 | */ |
| 543 | long getLong(const char *sym, long def = 0); |
| 544 | |
| 545 | /** |
| 546 | * Get a bool value. |
| 547 | * |
| 548 | * @param sym keyword name. |
| 549 | * @return true or false. |
| 550 | */ |
| 551 | bool getBool(const char *key); |
| 552 | |
| 553 | /** |
| 554 | * Get a floating value. |
| 555 | * |
| 556 | * @param sym keyword name. |
| 557 | * @param default if not set. |
| 558 | * @return value of key. |
| 559 | */ |
| 560 | double getDouble(const char *key, double def = 0.); |
| 561 | |
| 562 | /** |
| 563 | * Get an index array of ALL keywords that are stored by the |
| 564 | * current keydata object. |
| 565 | * |
| 566 | * @return number of keywords found. |
| 567 | * @param data pointer of array to hold keyword strings. |
| 568 | * @param max number of entries the array can hold. |
| 569 | */ |
| 570 | unsigned getIndex(char **data, unsigned max); |
| 571 | |
| 572 | /** |
| 573 | * Get the count of keyword indexes that are actually available |
| 574 | * so one can allocate a table to receive getIndex. |
| 575 | * |
| 576 | * @return number of keywords found. |
| 577 | */ |
| 578 | unsigned getCount(void); |
| 579 | |
| 580 | /** |
| 581 | * Set (replace) the value of a given keyword. This new value |
| 582 | * will become the value returned from getLast(), while the |
| 583 | * prior value will still be stored and found from <code>getList()</code>. |
| 584 | * |
| 585 | * @param sym keyword name to set. |
| 586 | * @param data string to store for the keyword. |
| 587 | */ |
| 588 | void setValue(const char *sym, const char *data); |
| 589 | |
| 590 | /** |
| 591 | * Return a list of all values set for the given keyword |
| 592 | * returned in order. |
| 593 | * |
| 594 | * @return list pointer of array holding all keyword values. |
| 595 | * @param sym keyword name to fetch. |
| 596 | */ |
| 597 | const char * const* getList(const char *sym); |
| 598 | |
| 599 | /** |
| 600 | * Clear all values associated with a given keyword. This does |
| 601 | * not de-allocate the keyword from memory, however. |
| 602 | * |
| 603 | * @return keyword name to clear. |
| 604 | */ |
| 605 | void clrValue(const char *sym); |
| 606 | |
| 607 | /** |
| 608 | * A convient notation for accessing the keydata as an associative |
| 609 | * array of keyword/value pairs through the [] operator. |
| 610 | */ |
| 611 | inline const char *operator[](const char *keyword) |
| 612 | {return getLast(keyword);}; |
| 613 | |
| 614 | /** |
| 615 | * static member to end keydata i/o allocations. |
| 616 | */ |
| 617 | static void end(void); |
| 618 | |
| 619 | /** |
| 620 | * Shutdown the file stream cache. This should be used before |
| 621 | * detaching a deamon, <code>exec()</code>, <code>fork()</code>, etc. |
| 622 | */ |
| 623 | friend inline void endKeydata(void) |
| 624 | {Keydata::end();}; |
| 625 | }; |
| 626 | |
| 627 | /** |
| 628 | * This class is used to create derived classes which are constructed |
| 629 | * within a memory pager pool. |
| 630 | * |
| 631 | * @short create objects in a memory pager. |
| 632 | * @author David Sugar <dyfet@ostel.com> |
| 633 | */ |
| 634 | class __EXPORT MemPagerObject |
| 635 | { |
| 636 | public: |
| 637 | /** |
| 638 | * Allocate memory from a memory pager. |
| 639 | * |
| 640 | * @param size of new passed from operator. |
| 641 | * @param pager to allocate from. |
| 642 | */ |
| 643 | inline void *operator new(size_t size, MemPager &pager) |
| 644 | {return pager.alloc(size);}; |
| 645 | |
| 646 | /** |
| 647 | * Allocate array from a memory pager. |
| 648 | * |
| 649 | * @param size of new passed from operator. |
| 650 | * @param pager to allocate from. |
| 651 | */ |
| 652 | inline void *operator new[](size_t size, MemPager &pager) |
| 653 | {return pager.alloc(size);}; |
| 654 | |
| 655 | /** |
| 656 | * Mempager delete does nothing; the pool purges. |
| 657 | */ |
| 658 | inline void operator delete(void *) {}; |
| 659 | |
| 660 | /** |
| 661 | * Array mempager delete does nothing; the pool purges. |
| 662 | */ |
| 663 | inline void operator delete[](void *) {}; |
| 664 | }; |
| 665 | |
| 666 | /** |
| 667 | * This class is used to associate (object) pointers with named strings. |
| 668 | * A virtual is used to allocate memory which can be overriden in the |
| 669 | * derived class. |
| 670 | * |
| 671 | * @author David Sugar <dyfet@ostel.com> |
| 672 | * @short associate names with pointers. |
| 673 | */ |
| 674 | class __EXPORT Assoc |
| 675 | { |
| 676 | private: |
| 677 | struct entry { |
| 678 | const char *id; |
| 679 | entry *next; |
| 680 | void *data; |
| 681 | }; |
| 682 | |
| 683 | entry *entries[KEYDATA_INDEX_SIZE]; |
| 684 | |
| 685 | protected: |
| 686 | Assoc(); |
| 687 | virtual ~Assoc(); |
| 688 | |
| 689 | void clear(void); |
| 690 | |
| 691 | virtual void *getMemory(size_t size) = 0; |
| 692 | |
| 693 | public: |
| 694 | void *getPointer(const char *id) const; |
| 695 | void setPointer(const char *id, void *data); |
| 696 | }; |
| 697 | |
| 698 | /** |
| 699 | * A runlist is used to restrict concurrent exection to a limited set |
| 700 | * of concurrent sessions, much like a semaphore. However, the runlist |
| 701 | * differs in that it notifies objects when they become ready to run, |
| 702 | * rather than requiring them to wait and "block" for the semaphore |
| 703 | * count to become low enough to continue. |
| 704 | * |
| 705 | * @author David Sugar <dyfet@ostel.com> |
| 706 | * @short list of runable objects. |
| 707 | */ |
| 708 | class __EXPORT Runlist : public Mutex |
| 709 | { |
| 710 | private: |
| 711 | Runable *first, *last; |
| 712 | |
| 713 | protected: |
| 714 | unsigned limit, used; |
| 715 | void check(void); |
| 716 | |
| 717 | public: |
| 718 | /** |
| 719 | * Create a new runlist with a specified limit. |
| 720 | * |
| 721 | * @param count limit before wait queuing. |
| 722 | */ |
| 723 | Runlist(unsigned count = 1); |
| 724 | |
| 725 | /** |
| 726 | * Add a runable object to this runlist. If the number of |
| 727 | * entries running is below the limit, then add returns true |
| 728 | * otherwise the entry is added to the list. |
| 729 | * |
| 730 | * @return true if immediately ready to run |
| 731 | * @param run pointer to runable object. |
| 732 | */ |
| 733 | bool add(Runable *run); |
| 734 | |
| 735 | /** |
| 736 | * Remove a runable object from the wait list or notify when |
| 737 | * it is done running so that the used count can be decremented. |
| 738 | * |
| 739 | * @param run pointer to runable object. |
| 740 | */ |
| 741 | void del(Runable *run); |
| 742 | |
| 743 | /** |
| 744 | * Set the limit. |
| 745 | * |
| 746 | * @param limit to use. |
| 747 | */ |
| 748 | void set(unsigned limit); |
| 749 | }; |
| 750 | |
| 751 | /** |
| 752 | * A container for objects that can be queued against a runlist. |
| 753 | * |
| 754 | * @author David Sugar <dyfet@ostel.com> |
| 755 | * @short runable object with notify when ready. |
| 756 | */ |
| 757 | class __EXPORT Runable |
| 758 | { |
| 759 | private: |
| 760 | friend class Runlist; |
| 761 | Runlist *list; |
| 762 | Runable *next, *prev; |
| 763 | |
| 764 | protected: |
| 765 | Runable(); |
| 766 | virtual ~Runable(); |
| 767 | |
| 768 | /** |
| 769 | * Method handler that is invoked when a wait-listed object |
| 770 | * becomes ready to run. |
| 771 | */ |
| 772 | virtual void ready(void) = 0; |
| 773 | |
| 774 | public: |
| 775 | /** |
| 776 | * Start the object against a run list. |
| 777 | * |
| 778 | * @return true if immediately available to run. |
| 779 | * @param list to start under. |
| 780 | */ |
| 781 | bool starting(Runlist *list); |
| 782 | |
| 783 | /** |
| 784 | * Stop the object, called when stopping or ready completes. |
| 785 | * May also be used for a task that has not yet started to |
| 786 | * remove it from the wait list. |
| 787 | */ |
| 788 | void stoping(void); |
| 789 | }; |
| 790 | |
| 791 | #ifdef CCXX_NAMESPACES |
| 792 | } |
| 793 | #endif |
| 794 | |
| 795 | #endif |
| 796 | |
| 797 | /** EMACS ** |
| 798 | * Local variables: |
| 799 | * mode: c++ |
| 800 | * c-basic-offset: 4 |
| 801 | * End: |
| 802 | */ |