From fd52342713012ec111b1559fa1647f88768fa782 Mon Sep 17 00:00:00 2001

From: Michael Schroeder <mls@suse.de>

Date: Wed, 16 Mar 2022 15:17:20 +0100

Subject: [PATCH 3/3] Improve choice rule generation

New strategy: take the package update map into account when creating

choice rules. This simplifies the code quite a bit. Also check at

the end of the solving if a choice rule led to two packages providing

the same thing. In that case, break the choice rule and re-run the

solver.

---

 src/rules.c  | 169 +++++++++++++--------------------------------------

 src/solver.c |  45 ++++++++++++++

 2 files changed, 88 insertions(+), 126 deletions(-)

diff --git a/src/rules.c b/src/rules.c

index 212df322..324fe5da 100644

--- a/src/rules.c

+++ b/src/rules.c

@@ -3139,6 +3139,12 @@ solver_rule2rules(Solver *solv, Id rid, Queue *q, int recursive)

 /* check if the newest versions of pi still provides the dependency we're looking for */

+/* pi: installed package

+ * r: rule for the dependency

+ * m: map with all positive elements of r

+ * return 0: at least one provider

+ * return 1: the newest versions do not provide the dependency

+ */

 static int

 solver_choicerulecheck(Solver *solv, Id pi, Rule *r, Map *m, Queue *q)

 {

@@ -3187,94 +3193,6 @@ solver_choicerulecheck(Solver *solv, Id pi, Rule *r, Map *m, Queue *q)

   return 1;	/* none of the new packages provided it */

 }

-static int

-solver_choicerulecheck2(Solver *solv, Id pi, Id pt, Queue *q)

-{

-  Pool *pool = solv->pool;

-  Rule *ur;

-  Id p, pp;

-  int i;

-

-  if (!q->count || q->elements[0] != pi)

-    {

-      if (q->count)

-        queue_empty(q);

-      ur = solv->rules + solv->updaterules + (pi - pool->installed->start);

-      if (!ur->p)

-        ur = solv->rules + solv->featurerules + (pi - pool->installed->start);

-      if (!ur->p)

-	return 1;		/* orphaned, thus newest */

-      queue_push2(q, pi, 0);

-      FOR_RULELITERALS(p, pp, ur)

-	if (p > 0 && p != pi)

-	  queue_push(q, p);

-      queue_push(q, pi);

-    }

-  if (q->count <= 3)

-    return q->count == 3 && q->elements[2] == pt ? 1 : 0;

-  if (!q->elements[1])

-    {

-      queue_deleten(q, 0, 2);

-      policy_filter_unwanted(solv, q, POLICY_MODE_CHOOSE);

-      queue_unshift(q, 1);	/* filter mark */

-      queue_unshift(q, pi);

-    }

-  for (i = 2; i < q->count; i++)

-    if (q->elements[i] == pt)

-      return 1;

-  return 0;	/* not newest */

-}

-

-static int

-solver_choicerulecheck3(Solver *solv, Id pt, Queue *q)

-{

-  Pool *pool = solv->pool;

-  Id p, pp;

-  int i;

-

-  if (!q->count || q->elements[0] != pt)

-    {

-      Solvable *s = pool->solvables + pt;

-      if (q->count)

-        queue_empty(q);

-      /* no installed package, so check all with same name */

-      queue_push2(q, pt, 0);

-      FOR_PROVIDES(p, pp, s->name)

-        if (pool->solvables[p].name == s->name && p != pt)

-          queue_push(q, p);

-      queue_push(q, pt);

-    }

-  if (q->count <= 3)

-    return q->count == 3 && q->elements[2] == pt ? 1 : 0;

-  if (!q->elements[1])

-    {

-      queue_deleten(q, 0, 2);

-      policy_filter_unwanted(solv, q, POLICY_MODE_CHOOSE);

-      queue_unshift(q, 1);	/* filter mark */

-      queue_unshift(q, pt);

-    }

-  for (i = 2; i < q->count; i++)

-    if (q->elements[i] == pt)

-      return 1;

-  return 0;	/* not newest */

-}

-

-static inline void

-queue_removeelement(Queue *q, Id el)

-{

-  int i, j;

-  for (i = 0; i < q->count; i++)

-    if (q->elements[i] == el)

-      break;

-  if (i < q->count)

-    {

-      for (j = i++; i < q->count; i++)

-	if (q->elements[i] != el)

-	  q->elements[j++] = q->elements[i];

-      queue_truncate(q, j);

-    }

-}

-

 static Id

 choicerule_find_installed(Pool *pool, Id p)

 {

@@ -3323,14 +3241,14 @@ solver_addchoicerules(Solver *solv)

   Pool *pool = solv->pool;

   Map m, mneg;

   Rule *r;

-  Queue q, qi, qcheck, qcheck2, infoq;

+  Queue q, qi, qcheck, infoq;

   int i, j, rid, havechoice, negcnt;

   Id p, d, pp, p2;

   Solvable *s;

   Id lastaddedp, lastaddedd;

   int lastaddedcnt;

   unsigned int now;

-  int isnewest = 0;

+  int isinstalled;

   solv->choicerules = solv->nrules;

   if (!pool->installed)

@@ -3342,7 +3260,6 @@ solver_addchoicerules(Solver *solv)

   queue_init(&q);

   queue_init(&qi);

   queue_init(&qcheck);

-  queue_init(&qcheck2);

   queue_init(&infoq);

   map_init(&m, pool->nsolvables);

   map_init(&mneg, pool->nsolvables);

@@ -3362,20 +3279,28 @@ solver_addchoicerules(Solver *solv)

       if (r->p >= 0 || ((r->d == 0 || r->d == -1) && r->w2 <= 0))

 	continue;	/* only look at requires rules */

       /* solver_printrule(solv, SOLV_DEBUG_RESULT, r); */

-      queue_empty(&q);

       queue_empty(&qi);

       havechoice = 0;

+      isinstalled = 0;

       FOR_RULELITERALS(p, pp, r)

 	{

 	  if (p < 0)

-	    continue;

+	    {

+	      Solvable *s = pool->solvables - p;

+	      p2 = s->repo == pool->installed ? -p : 0;

+	      if (p2)

+		{

+		  if (!(solv->updatemap_all || (solv->updatemap.size && MAPTST(&solv->updatemap, p2 - solv->installed->start))))

+		    isinstalled = 1;

+		}

+	      continue;

+	    }

 	  s = pool->solvables + p;

 	  if (!s->repo)

 	    continue;

 	  if (s->repo == pool->installed)

 	    {

 	      queue_push2(&qi, p, p);

-	      queue_push(&q, p);

 	      continue;

 	    }

 	  /* find an installed package p2 that we can update/downgrade to p */

@@ -3387,7 +3312,6 @@ solver_addchoicerules(Solver *solv)

 	      if (policy_is_illegal(solv, pool->solvables + p2, s, 0))

 		continue;

 	      queue_push2(&qi, p2, p);

-	      queue_push(&q, p);

 	      continue;

 	    }

 	  /* package p is independent of the installed ones */

@@ -3396,47 +3320,31 @@ solver_addchoicerules(Solver *solv)

 #if 0

       printf("havechoice: %d qcount %d qicount %d\n", havechoice, q.count, qi.count);

 #endif

-      if (!havechoice || !q.count || !qi.count)

+      if (!havechoice || !qi.count)

 	continue;	/* no choice */

       FOR_RULELITERALS(p, pp, r)

         if (p > 0)

 	  MAPSET(&m, p);

-      isnewest = 1;

-      FOR_RULELITERALS(p, pp, r)

-	{

-	  if (p > 0)

-	    break;

-	  p2 = choicerule_find_installed(pool, -p);

-	  if (p2 && !solver_choicerulecheck2(solv, p2, -p, &qcheck2))

-	    {

-	      isnewest = 0;

-	      break;

-	    }

-	  if (!p2 && !solver_choicerulecheck3(solv, -p, &qcheck2))

-	    {

-	      isnewest = 0;

-	      break;

-	    }

-	}

-      /* do extra checking */

-      for (i = j = 0; i < qi.count; i += 2)

+      if (!isinstalled)

 	{

-	  p2 = qi.elements[i];

-	  if (!p2)

-	    continue;

-	  if (isnewest && solver_choicerulecheck(solv, p2, r, &m, &qcheck))

+	  /* do extra checking for packages related to installed packages */

+	  for (i = j = 0; i < qi.count; i += 2)

 	    {

-	      /* oops, remove element p from q */

-	      queue_removeelement(&q, qi.elements[i + 1]);

-	      continue;

+	      p2 = qi.elements[i];

+	      if (solv->updatemap_all || (solv->updatemap.size && MAPTST(&solv->updatemap, p2 - solv->installed->start)))

+		{

+		  if (solver_choicerulecheck(solv, p2, r, &m, &qcheck))

+		    continue;

+		}

+	      qi.elements[j++] = p2;

+	      qi.elements[j++] = qi.elements[i + 1];

 	    }

-	  qi.elements[j++] = p2;

+	  queue_truncate(&qi, j);

 	}

-      queue_truncate(&qi, j);

-      if (!q.count || !qi.count)

+      if (!qi.count)

 	{

 	  FOR_RULELITERALS(p, pp, r)

 	    if (p > 0)

@@ -3444,6 +3352,15 @@ solver_addchoicerules(Solver *solv)

 	  continue;

 	}

+      queue_empty(&q);

+      /* split q from qi */

+      for (i = j = 0; i < qi.count; i += 2)

+	{

+	  queue_push(&q, qi.elements[i + 1]);

+	  qi.elements[j++] = qi.elements[i];

+	}

+      queue_truncate(&qi, j);

+

       /* now check the update rules of the installed package.

        * if all packages of the update rules are contained in

@@ -3463,6 +3380,7 @@ solver_addchoicerules(Solver *solv)

 	      break;

 	  if (p)

 	    break;

+	  /* speed improvement: only check each package once */

 	  for (j = i + 1; j < qi.count; j++)

 	    if (qi.elements[i] == qi.elements[j])

 	      qi.elements[j] = 0;

@@ -3520,7 +3438,6 @@ solver_addchoicerules(Solver *solv)

   queue_free(&q);

   queue_free(&qi);

   queue_free(&qcheck);

-  queue_free(&qcheck2);

   queue_free(&infoq);

   map_free(&m);

   map_free(&mneg);

diff --git a/src/solver.c b/src/solver.c

index 1dc2c783..08029baa 100644

--- a/src/solver.c

+++ b/src/solver.c

@@ -2615,6 +2615,43 @@ resolve_orphaned(Solver *solv, int level, int disablerules, Queue *dq, int *reru

   return level;

 }

+int

+solver_check_unneeded_choicerules(Solver *solv)

+{

+  Pool *pool = solv->pool;

+  Rule *r, *or;

+  Id p, pp, p2, pp2;

+  int i;

+  int havedisabled = 0;

+

+  /* check if some choice rules could have been broken */

+  for (i = solv->choicerules, r = solv->rules + i; i < solv->choicerules_end; i++, r++)

+    {

+      if (r->d < 0)

+	continue;

+      or = solv->rules + solv->choicerules_info[i - solv->choicerules];

+      if (or->d < 0)

+	continue;

+      FOR_RULELITERALS(p, pp, or)

+	{

+	  if (p < 0 || solv->decisionmap[p] <= 0)

+	    continue;

+	  FOR_RULELITERALS(p2, pp2, r)

+	    if (p2 == p)

+	      break;

+	  if (!p2)

+	    {

+	      /* did not find p in choice rule, disable it */

+	      POOL_DEBUG(SOLV_DEBUG_SOLVER, "disabling unneeded choice rule #%d\n", i);

+	      solver_disablechoicerules(solv, r);

+	      havedisabled = 1;

+	      break;

+	    }

+	}

+    }

+  return havedisabled;

+}

+

 /*-------------------------------------------------------------------

  *

  * solver_run_sat

@@ -2800,6 +2837,14 @@ solver_run_sat(Solver *solv, int disablerules, int doweak)

 	  continue;

 	}

+      if (solv->choicerules != solv->choicerules_end && solver_check_unneeded_choicerules(solv))

+	{

+	  POOL_DEBUG(SOLV_DEBUG_SOLVER, "did choice rule minimization, rerunning solver\n");

+	  solver_reset(solv);

+	  level = 0;	/* restart from scratch */

+	  continue;

+	}

+

       if (solv->solution_callback)

 	{

 	  solv->solution_callback(solv, solv->solution_callback_data);

-- 

2.31.1