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 333 <!--
 334   "$Id: api-array.header 7266 2008-01-29 02:15:29Z mike $"
 335
 336   Array API header for the Common UNIX Printing System (CUPS).
 337
 338   Copyright 2008 by Apple Inc.
 339
 340   These coded instructions, statements, and computer programs are the
 341   property of Apple Inc. and are protected by Federal copyright
 342   law.  Distribution and use rights are outlined in the file "LICENSE.txt"
 343   which should have been included with this file.  If this file is
 344   file is missing or damaged, see the license at "http://www.cups.org/".
 345 -->
 346
 347 <div class='summary'><table summary='General Information'>
 348 <thead>
 349 <tr>
 350         <th>Header</th>
 351         <th>cups/array.h</th>
 352 </tr>
 353 </thead>
 354 <tbody>
 355 <tr>
 356         <th>Library</th>
 357         <td>-lcups</td>
 358 </tr>
 359 <tr>
 360         <th>See Also</th>
 361         <td>Programming: <a href='api-overview.html' target='_top'>Introduction to CUPS Programming</a></td>
 362 </tr>
 363 </tbody>
 364 </table></div>
 365 <h2 class="title">Contents</h2>
 366 <ul class="contents">
 367 </li>
 368 <li><a href="#OVERVIEW">Overview</a><ul class="subcontents">
 369 <li><a href="#MANAGING_ARRAYS">Managing Arrays</a></li>
 370 <li><a href="#FINDING_AND_ENUMERATING">Finding and Enumerating Elements</a></li>
 371 </ul></li>
 372 <li><a href="#FUNCTIONS">Functions</a><ul class="code">
 373 <li><a href="#cupsArrayAdd" title="Add an element to the array.">cupsArrayAdd</a></li>
 374 <li><a href="#cupsArrayClear" title="Clear the array.">cupsArrayClear</a></li>
 375 <li><a href="#cupsArrayCount" title="Get the number of elements in the array.">cupsArrayCount</a></li>
 376 <li><a href="#cupsArrayCurrent" title="Return the current element in the array.">cupsArrayCurrent</a></li>
 377 <li><a href="#cupsArrayDelete" title="Free all memory used by the array.">cupsArrayDelete</a></li>
 378 <li><a href="#cupsArrayDup" title="Duplicate the array.">cupsArrayDup</a></li>
 379 <li><a href="#cupsArrayFind" title="Find an element in the array.">cupsArrayFind</a></li>
 380 <li><a href="#cupsArrayFirst" title="Get the first element in the array.">cupsArrayFirst</a></li>
 381 <li><a href="#cupsArrayGetIndex" title="Get the index of the current element.">cupsArrayGetIndex</a></li>
 382 <li><a href="#cupsArrayGetInsert" title="Get the index of the last inserted element.">cupsArrayGetInsert</a></li>
 383 <li><a href="#cupsArrayIndex" title="Get the N-th element in the array.">cupsArrayIndex</a></li>
 384 <li><a href="#cupsArrayInsert" title="Insert an element in the array.">cupsArrayInsert</a></li>
 385 <li><a href="#cupsArrayLast" title="Get the last element in the array.">cupsArrayLast</a></li>
 386 <li><a href="#cupsArrayNew" title="Create a new array.">cupsArrayNew</a></li>
 387 <li><a href="#cupsArrayNew2" title="Create a new array with hash.">cupsArrayNew2</a></li>
 388 <li><a href="#cupsArrayNext" title="Get the next element in the array.">cupsArrayNext</a></li>
 389 <li><a href="#cupsArrayPrev" title="Get the previous element in the array.">cupsArrayPrev</a></li>
 390 <li><a href="#cupsArrayRemove" title="Remove an element from the array.">cupsArrayRemove</a></li>
 391 <li><a href="#cupsArrayRestore" title="Reset the current element to the last <a href="#cupsArraySave"><code>cupsArraySave</code></a>.">cupsArrayRestore</a></li>
 392 <li><a href="#cupsArraySave" title="Mark the current element for a later <a href="#cupsArrayRestore"><code>cupsArrayRestore</code></a>.">cupsArraySave</a></li>
 393 <li><a href="#cupsArrayUserData" title="Return the user data for an array.">cupsArrayUserData</a></li>
 394 </ul>
 395 <li><a href="#TYPES">Data Types</a><ul class="code">
 396         <li><a href="#cups_ahash_func_t" title="Array hash function">cups_ahash_func_t</a></li>
 397         <li><a href="#cups_array_func_t" title="Array comparison function">cups_array_func_t</a></li>
 398         <li><a href="#cups_array_t" title="CUPS array type">cups_array_t</a></li>
 399 </ul></li>
 400 </ul>
 401 <!--
 402   "$Id: api-array.shtml 7616 2008-05-28 00:34:13Z mike $"
 403
 404   Array API introduction for the Common UNIX Printing System (CUPS).
 405
 406   Copyright 2007-2008 by Apple Inc.
 407   Copyright 1997-2006 by Easy Software Products, all rights reserved.
 408
 409   These coded instructions, statements, and computer programs are the
 410   property of Apple Inc. and are protected by Federal copyright
 411   law.  Distribution and use rights are outlined in the file "LICENSE.txt"
 412   which should have been included with this file.  If this file is
 413   file is missing or damaged, see the license at "http://www.cups.org/".
 414 -->
 415
 416 <h2 class='title'><a name='OVERVIEW'>Overview</a></h2>
 417
 418 <p>The CUPS array API provides a high-performance generic array container.
 419 The contents of the array container can be sorted and the container itself is
 420 designed for optimal speed and memory usage under a wide variety of conditions.
 421 Sorted arrays use a binary search algorithm from the last found or inserted
 422 element to quickly find matching elements in the array. Arrays created with the
 423 optional hash function can often find elements with a single lookup. The
 424 <a href='#cups_array_t'><code>cups_array_t</code></a> type is used when
 425 referring to a CUPS array.</p>
 426
 427 <p>The CUPS scheduler (<tt>cupsd</tt>) and many of the CUPS API
 428 functions use the array API to efficiently manage large lists of
 429 data.</p>
 430
 431 <h3><a name='MANAGING_ARRAYS'>Managing Arrays</a></h3>
 432
 433 <p>Arrays are created using either the
 434 <a href='#cupsArrayNew'><code>cupsArrayNew</code></a> or
 435 <a href='#cupsArrayNew2'><code>cupsArrayNew2</code></a> functions. The
 436 first function creates a new array with the specified callback function
 437 and user data pointer:</p>
 438
 439 <pre class='example'>
 440 #include &lt;cups/array.h&gt;
 441
 442 static int compare_func(void *first, void *second, void *user_data);
 443
 444 void *user_data;
 445 <a href='#cups_array_t'>cups_array_t</a> *array = <a href='#cupsArrayNew'>cupsArrayNew</a>(compare_func, user_data);
 446 </pre>
 447
 448 <p>The comparison function (type
 449 <a href="#cups_arrayfunc_t"><code>cups_arrayfunc_t</code></a>) is called
 450 whenever an element is added to the array and can be <code>NULL</code> to
 451 create an unsorted array. The function returns -1 if the first element should
 452 come before the second, 0 if the first and second elements should have the same
 453 ordering, and 1 if the first element should come after the second.</p>
 454
 455 <p>The "user_data" pointer is passed to your comparison function. Pass
 456 <code>NULL</code> if you do not need to associate the elements in your array
 457 with additional information.</p>
 458
 459 <p>The <a href='#cupsArrayNew2'><code>cupsArrayNew2</code></a> function adds
 460 two more arguments to support hashed lookups, which can potentially provide
 461 instantaneous ("O(1)") lookups in your array:</p>
 462
 463 <pre class='example'>
 464 #include &lt;cups/array.h&gt;
 465
 466 #define HASH_SIZE 512 /* Size of hash table */
 467
 468 static int compare_func(void *first, void *second, void *user_data);
 469 static int hash_func(void *element, void *user_data);
 470
 471 void *user_data;
 472 <a href='#cups_array_t'>cups_array_t</a> *array = <a href='#cupsArrayNew2'>cupsArrayNew2</a>(compare_func, user_data, hash_func, HASH_SIZE);
 473 </pre>
 474
 475 <p>The hash function (type
 476 <a href="#cups_ahash_func_t"><code>cups_ahash_func_t</code></a>) should return a
 477 number from 0 to (hash_size-1) that (hopefully) uniquely identifies the
 478 element and is called whenever you look up an element in the array with
 479 <a href='#cupsArrayFind'><code>cupsArrayFind</code></a>. The hash size is
 480 only limited by available memory, but generally should not be larger than
 481 16384 to realize any performance improvement.</p>
 482
 483 <p>Once you have created the array, you add elements using the
 484 <a href='#cupsArrayAdd'><code>cupsArrayAdd</code></a>
 485 <a href='#cupsArrayInsert'><code>cupsArrayInsert</code></a> functions.
 486 The first function adds an element to the array, adding the new element
 487 after any elements that have the same order, while the second inserts the
 488 element before others with the same order. For unsorted arrays,
 489 <a href='#cupsArrayAdd'><code>cupsArrayAdd</code></a> appends the element to
 490 the end of the array while
 491 <a href='#cupsArrayInsert'><code>cupsArrayInsert</code></a> inserts the
 492 element at the beginning of the array. For example, the following code
 493 creates a sorted array of character strings:</p>
 494
 495 <pre class='example'>
 496 #include &lt;cups/array.h&gt;
 497
 498 /* Use strcmp() to compare strings - it will ignore the user_data pointer */
 499 <a href='#cups_array_t'>cups_array_t</a> *array = <a href='#cupsArrayNew'>cupsArrayNew</a>((<a href='#cups_array_func_t'>cups_array_func_t</a>)strcmp, NULL);
 500
 501 /* Add four strings to the array */
 502 <a href='#cupsArrayAdd'>cupsArrayAdd</a>(array, "One Fish");
 503 <a href='#cupsArrayAdd'>cupsArrayAdd</a>(array, "Two Fish");
 504 <a href='#cupsArrayAdd'>cupsArrayAdd</a>(array, "Red Fish");
 505 <a href='#cupsArrayAdd'>cupsArrayAdd</a>(array, "Blue Fish");
 506 </pre>
 507
 508 <p>Elements are removed using the
 509 <a href='#cupsArrayRemove'><code>cupsArrayRemove</code></a> function, for
 510 example:</p>
 511
 512 <pre class='example'>
 513 #include &lt;cups/array.h&gt;
 514
 515 /* Use strcmp() to compare strings - it will ignore the user_data pointer */
 516 <a href='#cups_array_t'>cups_array_t</a> *array = <a href='#cupsArrayNew'>cupsArrayNew</a>((<a href='#cups_array_func_t'>cups_array_func_t</a>)strcmp, NULL);
 517
 518 /* Add four strings to the array */
 519 <a href='#cupsArrayAdd'>cupsArrayAdd</a>(array, "One Fish");
 520 <a href='#cupsArrayAdd'>cupsArrayAdd</a>(array, "Two Fish");
 521 <a href='#cupsArrayAdd'>cupsArrayAdd</a>(array, "Red Fish");
 522 <a href='#cupsArrayAdd'>cupsArrayAdd</a>(array, "Blue Fish");
 523
 524 /* Remove "Red Fish" */
 525 <a href='#cupsArrayRemove'>cupsArrayRemove</a>(array, "Red Fish");
 526 </pre>
 527
 528 <p>Finally, you free the memory used by the array using the
 529 <a href='#cupsArrayDelete'><code>cupsArrayDelete</code></a> function. All
 530 of the memory for the array and hash table (if any) is freed, however <em>CUPS
 531 does not free the elements</em> - if necessary, you must allocate and free the
 532 elements yourself.</p>
 533
 534 <h3><a name='FINDING_AND_ENUMERATING'>Finding and Enumerating Elements</a></h3>
 535
 536 <p>CUPS provides several functions to find and enumerate elements in an
 537 array. Each one sets or updates a "current index" into the array, such that
 538 future lookups will start where the last one left off:</p>
 539
 540 <dl>
 541         <dt><a href='#cupsArrayFind'><code>cupsArrayFind</code></a></dt>
 542         <dd>Returns the first matching element.</dd>
 543         <dt><a href='#cupsArrayFirst'><code>cupsArrayFirst</code></a></dt>
 544         <dd>Returns the first element in the array.</dd>
 545         <dt><a href='#cupsArrayIndex'><code>cupsArrayIndex</code></a></dt>
 546         <dd>Returns the Nth element in the array, starting at 0.</dd>
 547         <dt><a href='#cupsArrayLast'><code>cupsArrayLast</code></a></dt>
 548         <dd>Returns the last element in the array.</dd>
 549         <dt><a href='#cupsArrayNext'><code>cupsArrayNext</code></a></dt>
 550         <dd>Returns the next element in the array.</dd>
 551         <dt><a href='#cupsArrayPrev'><code>cupsArrayPrev</code></a></dt>
 552         <dd>Returns the previous element in the array.</dd>
 553 </dl>
 554
 555 <p>Each of these functions returns <code>NULL</code> when there is no
 556 corresponding element.  For example, a simple <code>for</code> loop using the
 557 <a href='#cupsArrayFirst'><code>cupsArrayFirst</code></a> and
 558 <a href='#cupsArrayNext'><code>cupsArrayNext</code></a> functions will
 559 enumerate all of the strings in our previous example:</p>
 560
 561 <pre class='example'>
 562 #include &lt;cups/array.h&gt;
 563
 564 /* Use strcmp() to compare strings - it will ignore the user_data pointer */
 565 <a href='#cups_array_t'>cups_array_t</a> *array = <a href='#cupsArrayNew'>cupsArrayNew</a>((<a href='#cups_array_func_t'>cups_array_func_t</a>)strcmp, NULL);
 566
 567 /* Add four strings to the array */
 568 <a href='#cupsArrayAdd'>cupsArrayAdd</a>(array, "One Fish");
 569 <a href='#cupsArrayAdd'>cupsArrayAdd</a>(array, "Two Fish");
 570 <a href='#cupsArrayAdd'>cupsArrayAdd</a>(array, "Red Fish");
 571 <a href='#cupsArrayAdd'>cupsArrayAdd</a>(array, "Blue Fish");
 572
 573 /* Show all of the strings in the array */
 574 char *s;
 575 for (s = (char *)<a href='#cupsArrayFirst'>cupsArrayFirst</a>(array); s != NULL; s = (char *)<a href='#cupsArrayNext'>cupsArrayNext</a>(array))
 576   puts(s);
 577 </pre>
 578 <h2 class="title"><a name="FUNCTIONS">Functions</a></h2>
 579 <h3 class="function"><span class="info">&nbsp;CUPS 1.2&nbsp;</span><a name="cupsArrayAdd">cupsArrayAdd</a></h3>
 580 <p class="description">Add an element to the array.</p>
 581 <p class="code">
 582 int cupsArrayAdd (<br>
 583 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_t">cups_array_t</a> *a,<br>
 584 &nbsp;&nbsp;&nbsp;&nbsp;void *e<br>
 585 );</p>
 586 <h4 class="parameters">Parameters</h4>
 587 <dl>
 588 <dt>a</dt>
 589 <dd class="description">Array</dd>
 590 <dt>e</dt>
 591 <dd class="description">Element</dd>
 592 </dl>
 593 <h4 class="returnvalue">Return Value</h4>
 594 <p class="description">1 on success, 0 on failure</p>
 595 <h4 class="discussion">Discussion</h4>
 596 <p class="discussion">When adding an element to a sorted array, non-unique elements are
 597 appended at the end of the run of identical elements.  For unsorted arrays,
 598 the element is appended to the end of the array.
 599
 600 </p>
 601 <h3 class="function"><span class="info">&nbsp;CUPS 1.2&nbsp;</span><a name="cupsArrayClear">cupsArrayClear</a></h3>
 602 <p class="description">Clear the array.</p>
 603 <p class="code">
 604 void cupsArrayClear (<br>
 605 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_t">cups_array_t</a> *a<br>
 606 );</p>
 607 <h4 class="parameters">Parameters</h4>
 608 <dl>
 609 <dt>a</dt>
 610 <dd class="description">Array</dd>
 611 </dl>
 612 <h4 class="discussion">Discussion</h4>
 613 <p class="discussion">This function is equivalent to removing all elements in the array.
 614 The caller is responsible for freeing the memory used by the
 615 elements themselves.
 616
 617 </p>
 618 <h3 class="function"><span class="info">&nbsp;CUPS 1.2&nbsp;</span><a name="cupsArrayCount">cupsArrayCount</a></h3>
 619 <p class="description">Get the number of elements in the array.</p>
 620 <p class="code">
 621 int cupsArrayCount (<br>
 622 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_t">cups_array_t</a> *a<br>
 623 );</p>
 624 <h4 class="parameters">Parameters</h4>
 625 <dl>
 626 <dt>a</dt>
 627 <dd class="description">Array</dd>
 628 </dl>
 629 <h4 class="returnvalue">Return Value</h4>
 630 <p class="description">Number of elements</p>
 631 <h3 class="function"><span class="info">&nbsp;CUPS 1.2&nbsp;</span><a name="cupsArrayCurrent">cupsArrayCurrent</a></h3>
 632 <p class="description">Return the current element in the array.</p>
 633 <p class="code">
 634 void *cupsArrayCurrent (<br>
 635 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_t">cups_array_t</a> *a<br>
 636 );</p>
 637 <h4 class="parameters">Parameters</h4>
 638 <dl>
 639 <dt>a</dt>
 640 <dd class="description">Array</dd>
 641 </dl>
 642 <h4 class="returnvalue">Return Value</h4>
 643 <p class="description">Element</p>
 644 <h4 class="discussion">Discussion</h4>
 645 <p class="discussion">The current element is undefined until you call <a href="#cupsArrayFind"><code>cupsArrayFind</code></a>,
 646 <a href="#cupsArrayFirst"><code>cupsArrayFirst</code></a>, or <a href="#cupsArrayIndex"><code>cupsArrayIndex</code></a>, or <a href="#cupsArrayLast"><code>cupsArrayLast</code></a>.
 647
 648 </p>
 649 <h3 class="function"><span class="info">&nbsp;CUPS 1.2&nbsp;</span><a name="cupsArrayDelete">cupsArrayDelete</a></h3>
 650 <p class="description">Free all memory used by the array.</p>
 651 <p class="code">
 652 void cupsArrayDelete (<br>
 653 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_t">cups_array_t</a> *a<br>
 654 );</p>
 655 <h4 class="parameters">Parameters</h4>
 656 <dl>
 657 <dt>a</dt>
 658 <dd class="description">Array</dd>
 659 </dl>
 660 <h4 class="discussion">Discussion</h4>
 661 <p class="discussion">The caller is responsible for freeing the memory used by the
 662 elements themselves.
 663
 664 </p>
 665 <h3 class="function"><span class="info">&nbsp;CUPS 1.2&nbsp;</span><a name="cupsArrayDup">cupsArrayDup</a></h3>
 666 <p class="description">Duplicate the array.</p>
 667 <p class="code">
 668 <a href="#cups_array_t">cups_array_t</a> *cupsArrayDup (<br>
 669 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_t">cups_array_t</a> *a<br>
 670 );</p>
 671 <h4 class="parameters">Parameters</h4>
 672 <dl>
 673 <dt>a</dt>
 674 <dd class="description">Array</dd>
 675 </dl>
 676 <h4 class="returnvalue">Return Value</h4>
 677 <p class="description">Duplicate array</p>
 678 <h3 class="function"><span class="info">&nbsp;CUPS 1.2&nbsp;</span><a name="cupsArrayFind">cupsArrayFind</a></h3>
 679 <p class="description">Find an element in the array.</p>
 680 <p class="code">
 681 void *cupsArrayFind (<br>
 682 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_t">cups_array_t</a> *a,<br>
 683 &nbsp;&nbsp;&nbsp;&nbsp;void *e<br>
 684 );</p>
 685 <h4 class="parameters">Parameters</h4>
 686 <dl>
 687 <dt>a</dt>
 688 <dd class="description">Array</dd>
 689 <dt>e</dt>
 690 <dd class="description">Element</dd>
 691 </dl>
 692 <h4 class="returnvalue">Return Value</h4>
 693 <p class="description">Element found or <code>NULL</code></p>
 694 <h3 class="function"><span class="info">&nbsp;CUPS 1.2&nbsp;</span><a name="cupsArrayFirst">cupsArrayFirst</a></h3>
 695 <p class="description">Get the first element in the array.</p>
 696 <p class="code">
 697 void *cupsArrayFirst (<br>
 698 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_t">cups_array_t</a> *a<br>
 699 );</p>
 700 <h4 class="parameters">Parameters</h4>
 701 <dl>
 702 <dt>a</dt>
 703 <dd class="description">Array</dd>
 704 </dl>
 705 <h4 class="returnvalue">Return Value</h4>
 706 <p class="description">First element or <code>NULL</code> if the array is empty</p>
 707 <h3 class="function"><span class="info">&nbsp;CUPS 1.3&nbsp;</span><a name="cupsArrayGetIndex">cupsArrayGetIndex</a></h3>
 708 <p class="description">Get the index of the current element.</p>
 709 <p class="code">
 710 int cupsArrayGetIndex (<br>
 711 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_t">cups_array_t</a> *a<br>
 712 );</p>
 713 <h4 class="parameters">Parameters</h4>
 714 <dl>
 715 <dt>a</dt>
 716 <dd class="description">Array</dd>
 717 </dl>
 718 <h4 class="returnvalue">Return Value</h4>
 719 <p class="description">Index of the current element, starting at 0</p>
 720 <h4 class="discussion">Discussion</h4>
 721 <p class="discussion">The current element is undefined until you call <a href="#cupsArrayFind"><code>cupsArrayFind</code></a>,
 722 <a href="#cupsArrayFirst"><code>cupsArrayFirst</code></a>, or <a href="#cupsArrayIndex"><code>cupsArrayIndex</code></a>, or <a href="#cupsArrayLast"><code>cupsArrayLast</code></a>.
 723
 724 </p>
 725 <h3 class="function"><span class="info">&nbsp;CUPS 1.3&nbsp;</span><a name="cupsArrayGetInsert">cupsArrayGetInsert</a></h3>
 726 <p class="description">Get the index of the last inserted element.</p>
 727 <p class="code">
 728 int cupsArrayGetInsert (<br>
 729 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_t">cups_array_t</a> *a<br>
 730 );</p>
 731 <h4 class="parameters">Parameters</h4>
 732 <dl>
 733 <dt>a</dt>
 734 <dd class="description">Array</dd>
 735 </dl>
 736 <h4 class="returnvalue">Return Value</h4>
 737 <p class="description">Index of the last inserted element, starting at 0</p>
 738 <h3 class="function"><span class="info">&nbsp;CUPS 1.2&nbsp;</span><a name="cupsArrayIndex">cupsArrayIndex</a></h3>
 739 <p class="description">Get the N-th element in the array.</p>
 740 <p class="code">
 741 void *cupsArrayIndex (<br>
 742 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_t">cups_array_t</a> *a,<br>
 743 &nbsp;&nbsp;&nbsp;&nbsp;int n<br>
 744 );</p>
 745 <h4 class="parameters">Parameters</h4>
 746 <dl>
 747 <dt>a</dt>
 748 <dd class="description">Array</dd>
 749 <dt>n</dt>
 750 <dd class="description">Index into array, starting at 0</dd>
 751 </dl>
 752 <h4 class="returnvalue">Return Value</h4>
 753 <p class="description">N-th element or <code>NULL</code></p>
 754 <h3 class="function"><span class="info">&nbsp;CUPS 1.2&nbsp;</span><a name="cupsArrayInsert">cupsArrayInsert</a></h3>
 755 <p class="description">Insert an element in the array.</p>
 756 <p class="code">
 757 int cupsArrayInsert (<br>
 758 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_t">cups_array_t</a> *a,<br>
 759 &nbsp;&nbsp;&nbsp;&nbsp;void *e<br>
 760 );</p>
 761 <h4 class="parameters">Parameters</h4>
 762 <dl>
 763 <dt>a</dt>
 764 <dd class="description">Array</dd>
 765 <dt>e</dt>
 766 <dd class="description">Element</dd>
 767 </dl>
 768 <h4 class="returnvalue">Return Value</h4>
 769 <p class="description">0 on failure, 1 on success</p>
 770 <h4 class="discussion">Discussion</h4>
 771 <p class="discussion">When inserting an element in a sorted array, non-unique elements are
 772 inserted at the beginning of the run of identical elements.  For unsorted
 773 arrays, the element is inserted at the beginning of the array.
 774
 775 </p>
 776 <h3 class="function"><span class="info">&nbsp;CUPS 1.2&nbsp;</span><a name="cupsArrayLast">cupsArrayLast</a></h3>
 777 <p class="description">Get the last element in the array.</p>
 778 <p class="code">
 779 void *cupsArrayLast (<br>
 780 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_t">cups_array_t</a> *a<br>
 781 );</p>
 782 <h4 class="parameters">Parameters</h4>
 783 <dl>
 784 <dt>a</dt>
 785 <dd class="description">Array</dd>
 786 </dl>
 787 <h4 class="returnvalue">Return Value</h4>
 788 <p class="description">Last element or <code>NULL</code> if the array is empty</p>
 789 <h3 class="function"><span class="info">&nbsp;CUPS 1.2&nbsp;</span><a name="cupsArrayNew">cupsArrayNew</a></h3>
 790 <p class="description">Create a new array.</p>
 791 <p class="code">
 792 <a href="#cups_array_t">cups_array_t</a> *cupsArrayNew (<br>
 793 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_func_t">cups_array_func_t</a> f,<br>
 794 &nbsp;&nbsp;&nbsp;&nbsp;void *d<br>
 795 );</p>
 796 <h4 class="parameters">Parameters</h4>
 797 <dl>
 798 <dt>f</dt>
 799 <dd class="description">Comparison function or <code>NULL</code> for an unsorted array</dd>
 800 <dt>d</dt>
 801 <dd class="description">User data pointer or <code>NULL</code></dd>
 802 </dl>
 803 <h4 class="returnvalue">Return Value</h4>
 804 <p class="description">Array</p>
 805 <h4 class="discussion">Discussion</h4>
 806 <p class="discussion">The comparison function (&quot;f&quot;) is used to create a sorted array. The function
 807 receives pointers to two elements and the user data pointer (&quot;d&quot;) - the user
 808 data pointer argument can safely be omitted when not required so functions
 809 like <code>strcmp</code> can be used for sorted string arrays.
 810
 811 </p>
 812 <h3 class="function"><span class="info">&nbsp;CUPS 1.3&nbsp;</span><a name="cupsArrayNew2">cupsArrayNew2</a></h3>
 813 <p class="description">Create a new array with hash.</p>
 814 <p class="code">
 815 <a href="#cups_array_t">cups_array_t</a> *cupsArrayNew2 (<br>
 816 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_func_t">cups_array_func_t</a> f,<br>
 817 &nbsp;&nbsp;&nbsp;&nbsp;void *d,<br>
 818 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_ahash_func_t">cups_ahash_func_t</a> h,<br>
 819 &nbsp;&nbsp;&nbsp;&nbsp;int hsize<br>
 820 );</p>
 821 <h4 class="parameters">Parameters</h4>
 822 <dl>
 823 <dt>f</dt>
 824 <dd class="description">Comparison function or <code>NULL</code> for an unsorted array</dd>
 825 <dt>d</dt>
 826 <dd class="description">User data or <code>NULL</code></dd>
 827 <dt>h</dt>
 828 <dd class="description">Hash function or <code>NULL</code> for unhashed lookups</dd>
 829 <dt>hsize</dt>
 830 <dd class="description">Hash size (&gt;= 0)</dd>
 831 </dl>
 832 <h4 class="returnvalue">Return Value</h4>
 833 <p class="description">Array</p>
 834 <h4 class="discussion">Discussion</h4>
 835 <p class="discussion">The comparison function (&quot;f&quot;) is used to create a sorted array. The function
 836 receives pointers to two elements and the user data pointer (&quot;d&quot;) - the user
 837 data pointer argument can safely be omitted when not required so functions
 838 like <code>strcmp</code> can be used for sorted string arrays.<br>
 839 <br>
 840 The hash function (&quot;h&quot;) is used to implement cached lookups with the
 841 specified hash size (&quot;hsize&quot;).
 842
 843 </p>
 844 <h3 class="function"><span class="info">&nbsp;CUPS 1.2&nbsp;</span><a name="cupsArrayNext">cupsArrayNext</a></h3>
 845 <p class="description">Get the next element in the array.</p>
 846 <p class="code">
 847 void *cupsArrayNext (<br>
 848 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_t">cups_array_t</a> *a<br>
 849 );</p>
 850 <h4 class="parameters">Parameters</h4>
 851 <dl>
 852 <dt>a</dt>
 853 <dd class="description">Array</dd>
 854 </dl>
 855 <h4 class="returnvalue">Return Value</h4>
 856 <p class="description">Next element or <code>NULL</code></p>
 857 <h4 class="discussion">Discussion</h4>
 858 <p class="discussion">This function is equivalent to &quot;cupsArrayIndex(a, cupsArrayGetIndex(a) + 1)&quot;.<br>
 859 <br>
 860 The next element is undefined until you call <a href="#cupsArrayFind"><code>cupsArrayFind</code></a>,
 861 <a href="#cupsArrayFirst"><code>cupsArrayFirst</code></a>, or <a href="#cupsArrayIndex"><code>cupsArrayIndex</code></a>, or <a href="#cupsArrayLast"><code>cupsArrayLast</code></a>
 862 to set the current element.
 863
 864 </p>
 865 <h3 class="function"><span class="info">&nbsp;CUPS 1.2&nbsp;</span><a name="cupsArrayPrev">cupsArrayPrev</a></h3>
 866 <p class="description">Get the previous element in the array.</p>
 867 <p class="code">
 868 void *cupsArrayPrev (<br>
 869 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_t">cups_array_t</a> *a<br>
 870 );</p>
 871 <h4 class="parameters">Parameters</h4>
 872 <dl>
 873 <dt>a</dt>
 874 <dd class="description">Array</dd>
 875 </dl>
 876 <h4 class="returnvalue">Return Value</h4>
 877 <p class="description">Previous element or <code>NULL</code></p>
 878 <h4 class="discussion">Discussion</h4>
 879 <p class="discussion">This function is equivalent to &quot;cupsArrayIndex(a, cupsArrayGetIndex(a) - 1)&quot;.<br>
 880 <br>
 881 The previous element is undefined until you call <a href="#cupsArrayFind"><code>cupsArrayFind</code></a>,
 882 <a href="#cupsArrayFirst"><code>cupsArrayFirst</code></a>, or <a href="#cupsArrayIndex"><code>cupsArrayIndex</code></a>, or <a href="#cupsArrayLast"><code>cupsArrayLast</code></a>
 883 to set the current element.
 884
 885 </p>
 886 <h3 class="function"><span class="info">&nbsp;CUPS 1.2&nbsp;</span><a name="cupsArrayRemove">cupsArrayRemove</a></h3>
 887 <p class="description">Remove an element from the array.</p>
 888 <p class="code">
 889 int cupsArrayRemove (<br>
 890 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_t">cups_array_t</a> *a,<br>
 891 &nbsp;&nbsp;&nbsp;&nbsp;void *e<br>
 892 );</p>
 893 <h4 class="parameters">Parameters</h4>
 894 <dl>
 895 <dt>a</dt>
 896 <dd class="description">Array</dd>
 897 <dt>e</dt>
 898 <dd class="description">Element</dd>
 899 </dl>
 900 <h4 class="returnvalue">Return Value</h4>
 901 <p class="description">1 on success, 0 on failure</p>
 902 <h4 class="discussion">Discussion</h4>
 903 <p class="discussion">If more than one element matches &quot;e&quot;, only the first matching element is
 904 removed.<br>
 905 <br>
 906 The caller is responsible for freeing the memory used by the
 907 removed element.
 908
 909 </p>
 910 <h3 class="function"><span class="info">&nbsp;CUPS 1.2&nbsp;</span><a name="cupsArrayRestore">cupsArrayRestore</a></h3>
 911 <p class="description">Reset the current element to the last <a href="#cupsArraySave"><code>cupsArraySave</code></a>.</p>
 912 <p class="code">
 913 void *cupsArrayRestore (<br>
 914 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_t">cups_array_t</a> *a<br>
 915 );</p>
 916 <h4 class="parameters">Parameters</h4>
 917 <dl>
 918 <dt>a</dt>
 919 <dd class="description">Array</dd>
 920 </dl>
 921 <h4 class="returnvalue">Return Value</h4>
 922 <p class="description">New current element</p>
 923 <h3 class="function"><span class="info">&nbsp;CUPS 1.2&nbsp;</span><a name="cupsArraySave">cupsArraySave</a></h3>
 924 <p class="description">Mark the current element for a later <a href="#cupsArrayRestore"><code>cupsArrayRestore</code></a>.</p>
 925 <p class="code">
 926 int cupsArraySave (<br>
 927 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_t">cups_array_t</a> *a<br>
 928 );</p>
 929 <h4 class="parameters">Parameters</h4>
 930 <dl>
 931 <dt>a</dt>
 932 <dd class="description">Array</dd>
 933 </dl>
 934 <h4 class="returnvalue">Return Value</h4>
 935 <p class="description">1 on success, 0 on failure</p>
 936 <h4 class="discussion">Discussion</h4>
 937 <p class="discussion">The current element is undefined until you call <a href="#cupsArrayFind"><code>cupsArrayFind</code></a>,
 938 <a href="#cupsArrayFirst"><code>cupsArrayFirst</code></a>, or <a href="#cupsArrayIndex"><code>cupsArrayIndex</code></a>, or <a href="#cupsArrayLast"><code>cupsArrayLast</code></a>
 939 to set the current element.<br>
 940 <br>
 941 The save/restore stack is guaranteed to be at least 32 elements deep.
 942
 943 </p>
 944 <h3 class="function"><span class="info">&nbsp;CUPS 1.2&nbsp;</span><a name="cupsArrayUserData">cupsArrayUserData</a></h3>
 945 <p class="description">Return the user data for an array.</p>
 946 <p class="code">
 947 void *cupsArrayUserData (<br>
 948 &nbsp;&nbsp;&nbsp;&nbsp;<a href="#cups_array_t">cups_array_t</a> *a<br>
 949 );</p>
 950 <h4 class="parameters">Parameters</h4>
 951 <dl>
 952 <dt>a</dt>
 953 <dd class="description">Array</dd>
 954 </dl>
 955 <h4 class="returnvalue">Return Value</h4>
 956 <p class="description">User data</p>
 957 <h2 class="title"><a name="TYPES">Data Types</a></h2>
 958 <h3 class="typedef"><a name="cups_ahash_func_t">cups_ahash_func_t</a></h3>
 959 <p class="description">Array hash function</p>
 960 <p class="code">
 961 typedef int (*cups_ahash_func_t)(void *element, void *data);
 962 </p>
 963 <h3 class="typedef"><a name="cups_array_func_t">cups_array_func_t</a></h3>
 964 <p class="description">Array comparison function</p>
 965 <p class="code">
 966 typedef int (*cups_array_func_t)(void *first, void *second, void *data);
 967 </p>
 968 <h3 class="typedef"><a name="cups_array_t">cups_array_t</a></h3>
 969 <p class="description">CUPS array type</p>
 970 <p class="code">
 971 typedef struct _cups_array_s cups_array_t;
 972 </p>
 973 </div>
 974 </body>
 975 </html>