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Replace insertion sort in contrib/intarray with qsort().

It's all very well to claim that a simplistic sort is fast in easycases, but O(N^2) in the worst case is not good ... especially if theworst case is as easy to hit as "descending order input". Replace thatbit with our standard qsort.Per bug #12866 from Maksym Boguk. Back-patch to all active branches.

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contrib/intarray
- _int_tool.c

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+23

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`‎contrib/intarray/_int_tool.c`

Lines changed: 23 additions & 29 deletions

Original file line number	Diff line number	Diff line change
`@@ -184,40 +184,34 @@ rt__int_size(ArrayType a, float size)`
`184`	`184`	`*size= (float)ARRNELEMS(a);`
`185`	`185`	`}`
`186`	`186`
	`187`	`+/* qsort_arg comparison function for isort() */`
	`188`	`+staticint`
	`189`	`+isort_cmp(constvoida,constvoidb,void*arg)`
	`190`	`+{`
	`191`	`+int4aval=((constint4)a);`
	`192`	`+int4bval=((constint4)b);`
	`193`	`+`
	`194`	`+if (aval<bval)`
	`195`	`+return-1;`
	`196`	`+if (aval>bval)`
	`197`	`+return1;`
	`198`	`+`
	`199`	`+/*`
	`200`	`+ * Report if we have any duplicates. If there are equal keys, qsort must`
	`201`	`+ * compare them at some point, else it wouldn't know whether one should go`
	`202`	`+ * before or after the other.`
	`203`	`+ */`
	`204`	`+((bool)arg)= true;`
	`205`	`+return0;`
	`206`	`+}`
	`207`	`+`
`187`	`208`	`/* Sort the given data (len >= 2). Return true if any duplicates found */`
`188`	`209`	`bool`
`189`	`210`	`isort(int4*a,intlen)`
`190`	`211`	`{`
`191`		`-int4cur,`
`192`		`-prev;`
`193`		`-int4*pcur,`
`194`		`-*pprev,`
`195`		`-*end;`
`196`		`-boolr= FALSE;`
	`212`	`+boolr= false;`
`197`	`213`
`198`		`-/*`
`199`		`- * We use a simple insertion sort. While this is O(N^2) in the worst`
`200`		`- * case, it's quite fast if the input is already sorted or nearly so.`
`201`		`- * Also, for not-too-large inputs it's faster than more complex methods`
`202`		`- * anyhow.`
`203`		`- */`
`204`		`-end=a+len;`
`205`		`-for (pcur=a+1;pcur<end;pcur++)`
`206`		`-{`
`207`		`-cur=*pcur;`
`208`		`-for (pprev=pcur-1;pprev >=a;pprev--)`
`209`		`-{`
`210`		`-prev=*pprev;`
`211`		`-if (prev <=cur)`
`212`		`-{`
`213`		`-if (prev==cur)`
`214`		`-r= TRUE;`
`215`		`-break;`
`216`		`-}`
`217`		`-pprev[1]=prev;`
`218`		`-}`
`219`		`-pprev[1]=cur;`
`220`		`-}`
	`214`	`+qsort_arg(a,len,sizeof(int4),isort_cmp, (void*)&r);`
`221`	`215`	`returnr;`
`222`	`216`	`}`
`223`	`217`

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Commit9288645

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`‎contrib/intarray/_int_tool.c`

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