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-rw-r--r--xorg-server/record/set.c438
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diff --git a/xorg-server/record/set.c b/xorg-server/record/set.c
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+/*
+
+Copyright 1995, 1998 The Open Group
+
+Permission to use, copy, modify, distribute, and sell this software and its
+documentation for any purpose is hereby granted without fee, provided that
+the above copyright notice appear in all copies and that both that
+copyright notice and this permission notice appear in supporting
+documentation.
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+Except as contained in this notice, the name of The Open Group shall
+not be used in advertising or otherwise to promote the sale, use or
+other dealings in this Software without prior written authorization
+from The Open Group.
+
+*/
+
+/*
+
+ See the header set.h for a description of the set ADT.
+
+ Implementation Strategy
+
+ A bit vector is an obvious choice to represent the set, but may take
+ too much memory, depending on the numerically largest member in the
+ set. One expected common case is for the client to ask for *all*
+ protocol. This means it would ask for minor opcodes 0 through 65535.
+ Representing this as a bit vector takes 8K -- and there may be
+ multiple minor opcode intervals, as many as one per major (extension)
+ opcode). In such cases, a list-of-intervals representation would be
+ preferable to reduce memory consumption. Both representations will be
+ implemented, and RecordCreateSet will decide heuristically which one
+ to use based on the set members.
+
+*/
+
+#ifdef HAVE_DIX_CONFIG_H
+#include <dix-config.h>
+#endif
+
+#include <string.h>
+
+#include "misc.h"
+#include "set.h"
+
+static int
+maxMemberInInterval(RecordSetInterval *pIntervals, int nIntervals)
+{
+ int i;
+ int maxMember = -1;
+ for (i = 0; i < nIntervals; i++)
+ {
+ if (maxMember < (int)pIntervals[i].last)
+ maxMember = pIntervals[i].last;
+ }
+ return maxMember;
+}
+
+static void
+NoopDestroySet(RecordSetPtr pSet)
+{
+}
+
+/***************************************************************************/
+
+/* set operations for bit vector representation */
+
+typedef struct {
+ RecordSetRec baseSet;
+ int maxMember;
+ /* followed by the bit vector itself */
+} BitVectorSet, *BitVectorSetPtr;
+
+#define BITS_PER_LONG (sizeof(unsigned long) * 8)
+
+static void
+BitVectorDestroySet(RecordSetPtr pSet)
+{
+ xfree(pSet);
+}
+
+static unsigned long
+BitVectorIsMemberOfSet(RecordSetPtr pSet, int pm)
+{
+ BitVectorSetPtr pbvs = (BitVectorSetPtr)pSet;
+ unsigned long *pbitvec;
+
+ if ((int)pm > pbvs->maxMember) return FALSE;
+ pbitvec = (unsigned long *)(&pbvs[1]);
+ return (pbitvec[pm / BITS_PER_LONG] & ((unsigned long)1 << (pm % BITS_PER_LONG)));
+}
+
+
+static int
+BitVectorFindBit(RecordSetPtr pSet, int iterbit, Bool bitval)
+{
+ BitVectorSetPtr pbvs = (BitVectorSetPtr)pSet;
+ unsigned long *pbitvec = (unsigned long *)(&pbvs[1]);
+ int startlong;
+ int startbit;
+ int walkbit;
+ int maxMember;
+ unsigned long skipval;
+ unsigned long bits;
+ unsigned long usefulbits;
+
+ startlong = iterbit / BITS_PER_LONG;
+ pbitvec += startlong;
+ startbit = startlong * BITS_PER_LONG;
+ skipval = bitval ? 0L : ~0L;
+ maxMember = pbvs->maxMember;
+
+
+ if (startbit > maxMember) return -1;
+ bits = *pbitvec;
+ usefulbits = ~(((unsigned long)1 << (iterbit - startbit)) - 1);
+ if ( (bits & usefulbits) == (skipval & usefulbits) )
+ {
+ pbitvec++;
+ startbit += BITS_PER_LONG;
+
+ while (startbit <= maxMember && *pbitvec == skipval)
+ {
+ pbitvec++;
+ startbit += BITS_PER_LONG;
+ }
+ if (startbit > maxMember) return -1;
+ }
+
+ walkbit = (startbit < iterbit) ? iterbit - startbit : 0;
+
+ bits = *pbitvec;
+ while (walkbit < BITS_PER_LONG && ((!(bits & ((unsigned long)1 << walkbit))) == bitval))
+ walkbit++;
+
+ return startbit + walkbit;
+}
+
+
+static RecordSetIteratePtr
+BitVectorIterateSet(RecordSetPtr pSet, RecordSetIteratePtr pIter,
+ RecordSetInterval *pInterval)
+{
+ int iterbit = (int)(long)pIter;
+ int b;
+
+ b = BitVectorFindBit(pSet, iterbit, TRUE);
+ if (b == -1) return (RecordSetIteratePtr)0;
+ pInterval->first = b;
+
+ b = BitVectorFindBit(pSet, b, FALSE);
+ pInterval->last = (b < 0) ? ((BitVectorSetPtr)pSet)->maxMember : b - 1;
+ return (RecordSetIteratePtr)(long)(pInterval->last + 1);
+}
+
+static RecordSetOperations BitVectorSetOperations = {
+ BitVectorDestroySet, BitVectorIsMemberOfSet, BitVectorIterateSet };
+
+static RecordSetOperations BitVectorNoFreeOperations = {
+ NoopDestroySet, BitVectorIsMemberOfSet, BitVectorIterateSet };
+
+static int
+BitVectorSetMemoryRequirements(RecordSetInterval *pIntervals, int nIntervals,
+ int maxMember, int *alignment)
+{
+ int nlongs;
+
+ *alignment = sizeof(unsigned long);
+ nlongs = (maxMember + BITS_PER_LONG) / BITS_PER_LONG;
+ return (sizeof(BitVectorSet) + nlongs * sizeof(unsigned long));
+}
+
+static RecordSetPtr
+BitVectorCreateSet(RecordSetInterval *pIntervals, int nIntervals,
+ void *pMem, int memsize)
+{
+ BitVectorSetPtr pbvs;
+ int i, j;
+ unsigned long *pbitvec;
+
+ /* allocate all storage needed by this set in one chunk */
+
+ if (pMem)
+ {
+ memset(pMem, 0, memsize);
+ pbvs = (BitVectorSetPtr)pMem;
+ pbvs->baseSet.ops = &BitVectorNoFreeOperations;
+ }
+ else
+ {
+ pbvs = (BitVectorSetPtr)Xcalloc(memsize);
+ if (!pbvs) return NULL;
+ pbvs->baseSet.ops = &BitVectorSetOperations;
+ }
+
+ pbvs->maxMember = maxMemberInInterval(pIntervals, nIntervals);
+
+ /* fill in the set */
+
+ pbitvec = (unsigned long *)(&pbvs[1]);
+ for (i = 0; i < nIntervals; i++)
+ {
+ for (j = pIntervals[i].first; j <= (int)pIntervals[i].last; j++)
+ {
+ pbitvec[j/BITS_PER_LONG] |= ((unsigned long)1 << (j % BITS_PER_LONG));
+ }
+ }
+ return (RecordSetPtr)pbvs;
+}
+
+
+/***************************************************************************/
+
+/* set operations for interval list representation */
+
+typedef struct {
+ RecordSetRec baseSet;
+ int nIntervals;
+ /* followed by the intervals (RecordSetInterval) */
+} IntervalListSet, *IntervalListSetPtr;
+
+static void
+IntervalListDestroySet(RecordSetPtr pSet)
+{
+ xfree(pSet);
+}
+
+static unsigned long
+IntervalListIsMemberOfSet(RecordSetPtr pSet, int pm)
+{
+ IntervalListSetPtr prls = (IntervalListSetPtr)pSet;
+ RecordSetInterval *pInterval = (RecordSetInterval *)(&prls[1]);
+ int hi, lo, probe;
+
+ /* binary search */
+ lo = 0; hi = prls->nIntervals - 1;
+ while (lo <= hi)
+ {
+ probe = (hi + lo) / 2;
+ if (pm >= pInterval[probe].first && pm <= pInterval[probe].last) return 1;
+ else if (pm < pInterval[probe].first) hi = probe - 1;
+ else lo = probe + 1;
+ }
+ return 0;
+}
+
+
+static RecordSetIteratePtr
+IntervalListIterateSet(RecordSetPtr pSet, RecordSetIteratePtr pIter,
+ RecordSetInterval *pIntervalReturn)
+{
+ RecordSetInterval *pInterval = (RecordSetInterval *)pIter;
+ IntervalListSetPtr prls = (IntervalListSetPtr)pSet;
+
+ if (pInterval == NULL)
+ {
+ pInterval = (RecordSetInterval *)(&prls[1]);
+ }
+
+ if ( (pInterval - (RecordSetInterval *)(&prls[1])) < prls->nIntervals )
+ {
+ *pIntervalReturn = *pInterval;
+ return (RecordSetIteratePtr)(++pInterval);
+ }
+ else
+ return (RecordSetIteratePtr)NULL;
+}
+
+static RecordSetOperations IntervalListSetOperations = {
+ IntervalListDestroySet, IntervalListIsMemberOfSet, IntervalListIterateSet };
+
+static RecordSetOperations IntervalListNoFreeOperations = {
+ NoopDestroySet, IntervalListIsMemberOfSet, IntervalListIterateSet };
+
+static int
+IntervalListMemoryRequirements(RecordSetInterval *pIntervals, int nIntervals,
+ int maxMember, int *alignment)
+{
+ *alignment = sizeof(unsigned long);
+ return sizeof(IntervalListSet) + nIntervals * sizeof(RecordSetInterval);
+}
+
+static RecordSetPtr
+IntervalListCreateSet(RecordSetInterval *pIntervals, int nIntervals,
+ void *pMem, int memsize)
+{
+ IntervalListSetPtr prls;
+ int i, j, k;
+ RecordSetInterval *stackIntervals = NULL;
+ CARD16 first;
+
+ if (nIntervals > 0)
+ {
+ stackIntervals = (RecordSetInterval *)xalloc(
+ sizeof(RecordSetInterval) * nIntervals);
+ if (!stackIntervals) return NULL;
+
+ /* sort intervals, store in stackIntervals (insertion sort) */
+
+ for (i = 0; i < nIntervals; i++)
+ {
+ first = pIntervals[i].first;
+ for (j = 0; j < i; j++)
+ {
+ if (first < stackIntervals[j].first)
+ break;
+ }
+ for (k = i; k > j; k--)
+ {
+ stackIntervals[k] = stackIntervals[k-1];
+ }
+ stackIntervals[j] = pIntervals[i];
+ }
+
+ /* merge abutting/overlapping intervals */
+
+ for (i = 0; i < nIntervals - 1; )
+ {
+ if ( (stackIntervals[i].last + (unsigned int)1) <
+ stackIntervals[i + 1].first)
+ {
+ i++; /* disjoint intervals */
+ }
+ else
+ {
+ stackIntervals[i].last = max(stackIntervals[i].last,
+ stackIntervals[i + 1].last);
+ nIntervals--;
+ for (j = i + 1; j < nIntervals; j++)
+ stackIntervals[j] = stackIntervals[j + 1];
+ }
+ }
+ }
+
+ /* allocate and fill in set structure */
+
+ if (pMem)
+ {
+ prls = (IntervalListSetPtr)pMem;
+ prls->baseSet.ops = &IntervalListNoFreeOperations;
+ }
+ else
+ {
+ prls = (IntervalListSetPtr)
+ xalloc(sizeof(IntervalListSet) + nIntervals * sizeof(RecordSetInterval));
+ if (!prls) goto bailout;
+ prls->baseSet.ops = &IntervalListSetOperations;
+ }
+ memcpy(&prls[1], stackIntervals, nIntervals * sizeof(RecordSetInterval));
+ prls->nIntervals = nIntervals;
+bailout:
+ if (stackIntervals) xfree(stackIntervals);
+ return (RecordSetPtr)prls;
+}
+
+typedef RecordSetPtr (*RecordCreateSetProcPtr)(
+ RecordSetInterval *pIntervals,
+ int nIntervals,
+ void *pMem,
+ int memsize
+);
+
+static int
+_RecordSetMemoryRequirements(RecordSetInterval *pIntervals, int nIntervals,
+ int *alignment,
+ RecordCreateSetProcPtr *ppCreateSet)
+{
+ int bmsize, rlsize, bma, rla;
+ int maxMember;
+
+ /* find maximum member of set so we know how big to make the bit vector */
+ maxMember = maxMemberInInterval(pIntervals, nIntervals);
+
+ bmsize = BitVectorSetMemoryRequirements(pIntervals, nIntervals, maxMember,
+ &bma);
+ rlsize = IntervalListMemoryRequirements(pIntervals, nIntervals, maxMember,
+ &rla);
+ if ( ( (nIntervals > 1) && (maxMember <= 255) )
+ || (bmsize < rlsize) )
+ {
+ *alignment = bma;
+ *ppCreateSet = BitVectorCreateSet;
+ return bmsize;
+ }
+ else
+ {
+ *alignment = rla;
+ *ppCreateSet = IntervalListCreateSet;
+ return rlsize;
+ }
+}
+
+/***************************************************************************/
+
+/* user-visible functions */
+
+int
+RecordSetMemoryRequirements(pIntervals, nIntervals, alignment)
+ RecordSetInterval *pIntervals;
+ int nIntervals;
+ int *alignment;
+{
+ RecordCreateSetProcPtr pCreateSet;
+ return _RecordSetMemoryRequirements(pIntervals, nIntervals, alignment,
+ &pCreateSet);
+}
+
+RecordSetPtr
+RecordCreateSet(pIntervals, nIntervals, pMem, memsize)
+ RecordSetInterval *pIntervals;
+ int nIntervals;
+ void *pMem;
+ int memsize;
+{
+ RecordCreateSetProcPtr pCreateSet;
+ int alignment;
+ int size;
+
+ size = _RecordSetMemoryRequirements(pIntervals, nIntervals, &alignment,
+ &pCreateSet);
+ if (pMem)
+ {
+ if ( ((long)pMem & (alignment-1) ) || memsize < size)
+ return NULL;
+ }
+ return (*pCreateSet)(pIntervals, nIntervals, pMem, size);
+}