1 files changed, 438 insertions, 0 deletions
diff --git a/xorg-server/record/set.c b/xorg-server/record/set.c
new file mode 100644
index 000000000..453452ec6
--- /dev/null
+++ b/xorg-server/record/set.c
@@ -0,0 +1,438 @@
+/*
+
+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);
+}