1 /* 2 3 Copyright 1995, 1998 The Open Group 4 5 Permission to use, copy, modify, distribute, and sell this software and its 6 documentation for any purpose is hereby granted without fee, provided that 7 the above copyright notice appear in all copies and that both that 8 copyright notice and this permission notice appear in supporting 9 documentation. 10 11 The above copyright notice and this permission notice shall be 12 included in all copies or substantial portions of the Software. 13 14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 15 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 16 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 17 IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR 18 OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 19 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 20 OTHER DEALINGS IN THE SOFTWARE. 21 22 Except as contained in this notice, the name of The Open Group shall 23 not be used in advertising or otherwise to promote the sale, use or 24 other dealings in this Software without prior written authorization 25 from The Open Group. 26 27 */ 28 29 /* 30 A Set Abstract Data Type (ADT) for the RECORD Extension 31 David P. Wiggins 32 7/25/95 33 34 The RECORD extension server code needs to maintain sets of numbers 35 that designate protocol message types. In most cases the interval of 36 numbers starts at 0 and does not exceed 255, but in a few cases (minor 37 opcodes of extension requests) the maximum is 65535. This disparity 38 suggests that a single set representation may not be suitable for all 39 sets, especially given that server memory is precious. We introduce a 40 set ADT to hide implementation differences so that multiple 41 simultaneous set representations can exist. A single interface is 42 presented to the set user regardless of the implementation in use for 43 a particular set. 44 45 The existing RECORD SI appears to require only four set operations: 46 create (given a list of members), destroy, see if a particular number 47 is a member of the set, and iterate over the members of a set. Though 48 many more set operations are imaginable, to keep the code space down, 49 we won't provide any more operations than are needed. 50 51 The following types and functions/macros define the ADT. 52 */ 53 54 /* an interval of set members */ 55 typedef struct { 56 CARD16 first; 57 CARD16 last; 58 } RecordSetInterval; 59 60 typedef struct _RecordSetRec *RecordSetPtr; /* primary set type */ 61 62 typedef void *RecordSetIteratePtr; 63 64 /* table of function pointers for set operations. 65 set users should never declare a variable of this type. 66 */ 67 typedef struct { 68 void (*DestroySet) (RecordSetPtr pSet); 69 unsigned long (*IsMemberOfSet) (RecordSetPtr pSet, int possible_member); 70 RecordSetIteratePtr(*IterateSet) (RecordSetPtr pSet, 71 RecordSetIteratePtr pIter, 72 RecordSetInterval * interval); 73 } RecordSetOperations; 74 75 /* "base class" for sets. 76 set users should never declare a variable of this type. 77 */ 78 typedef struct _RecordSetRec { 79 RecordSetOperations *ops; 80 } RecordSetRec; 81 82 RecordSetPtr RecordCreateSet(RecordSetInterval * intervals, 83 int nintervals, void *pMem, int memsize); 84 /* 85 RecordCreateSet creates and returns a new set having members specified 86 by intervals and nintervals. nintervals is the number of RecordSetInterval 87 structures pointed to by intervals. The elements belonging to the new 88 set are determined as follows. For each RecordSetInterval structure, the 89 elements between first and last inclusive are members of the new set. 90 If a RecordSetInterval's first field is greater than its last field, the 91 results are undefined. It is valid to create an empty set (nintervals == 92 0). If RecordCreateSet returns NULL, the set could not be created due 93 to resource constraints. 94 */ 95 96 int RecordSetMemoryRequirements(RecordSetInterval * /*pIntervals */ , 97 int /*nintervals */ , 98 int * /*alignment */ 99 ); 100 101 #define RecordDestroySet(_pSet) \ 102 /* void */ (*_pSet->ops->DestroySet)(/* RecordSetPtr */ _pSet) 103 /* 104 RecordDestroySet frees all resources used by _pSet. _pSet should not be 105 used after it is destroyed. 106 */ 107 108 #define RecordIsMemberOfSet(_pSet, _m) \ 109 /* unsigned long */ (*_pSet->ops->IsMemberOfSet)(/* RecordSetPtr */ _pSet, \ 110 /* int */ _m) 111 /* 112 RecordIsMemberOfSet returns a non-zero value if _m is a member of 113 _pSet, else it returns zero. 114 */ 115 116 #define RecordIterateSet(_pSet, _pIter, _interval) \ 117 /* RecordSetIteratePtr */ (*_pSet->ops->IterateSet)(/* RecordSetPtr */ _pSet,\ 118 /* RecordSetIteratePtr */ _pIter, /* RecordSetInterval */ _interval) 119 /* 120 RecordIterateSet returns successive intervals of members of _pSet. If 121 _pIter is NULL, the first interval of set members is copied into _interval. 122 The return value should be passed as _pIter in the next call to 123 RecordIterateSet to obtain the next interval. When the return value is 124 NULL, there were no more intervals in the set, and nothing is copied into 125 the _interval parameter. Intervals appear in increasing numerical order 126 with no overlap between intervals. As such, the list of intervals produced 127 by RecordIterateSet may not match the list of intervals that were passed 128 in RecordCreateSet. Typical usage: 129 130 pIter = NULL; 131 while (pIter = RecordIterateSet(pSet, pIter, &interval)) 132 { 133 process interval; 134 } 135 */ 136