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[platform/upstream/libsolv.git] / src / solver.h
1 /*
2  * Copyright (c) 2007, Novell Inc.
3  *
4  * This program is licensed under the BSD license, read LICENSE.BSD
5  * for further information
6  */
7
8 /*
9  * solver.h
10  *
11  */
12
13 #ifndef SATSOLVER_SOLVER_H
14 #define SATSOLVER_SOLVER_H
15
16 #include "pooltypes.h"
17 #include "pool.h"
18 #include "repo.h"
19 #include "queue.h"
20 #include "bitmap.h"
21
22 /* ----------------------------------------------
23  * Rule
24  *
25  *   providerN(B) == Package Id of package providing tag B
26  *   N = 1, 2, 3, in case of multiple providers
27  *
28  * A requires B : !A | provider1(B) | provider2(B)
29  *
30  * A conflicts B : (!A | !provider1(B)) & (!A | !provider2(B)) ...
31  *
32  * 'not' is encoded as a negative Id
33  * 
34  * Binary rule: p = first literal, d = 0, w2 = second literal, w1 = p
35  */
36
37 typedef struct rule {
38   Id p;                 /* first literal in rule */
39   Id d;                 /* Id offset into 'list of providers terminated by 0' as used by whatprovides; pool->whatprovides + d */
40                         /* in case of binary rules, d == 0, w1 == p, w2 == other literal */
41   Id w1, w2;            /* watches, literals not-yet-decided */
42                                        /* if !w1, disabled */
43                                        /* if !w2, assertion, not rule */
44   Id n1, n2;            /* next rules in linked list, corresponding to w1,w2 */
45 } Rule;
46
47 struct solver;
48
49 typedef struct solver {
50   Pool *pool;
51   Repo *installed;
52
53   int fixsystem;                        /* repair errors in rpm dependency graph */
54   int allowdowngrade;                   /* allow to downgrade installed solvable */
55   int allowarchchange;                  /* allow to change architecture of installed solvables */
56   int allowvendorchange;                /* allow to change vendor of installed solvables */
57   int allowuninstall;                   /* allow removal of installed solvables */
58   int updatesystem;                     /* distupgrade */
59   int allowvirtualconflicts;            /* false: conflicts on package name, true: conflicts on package provides */
60   int noupdateprovide;                  /* true: update packages needs not to provide old package */
61   
62   Rule *rules;                          /* all rules */
63   Id nrules;                            /* index of the last rule */
64
65   Id jobrules;                          /* user rules */
66   Id systemrules;                       /* policy rules, e.g. keep packages installed or update. All literals > 0 */
67   Id weakrules;                         /* rules that can be autodisabled */
68   Id learntrules;                       /* learnt rules */
69
70   Id *weaksystemrules;                  /* please try to install (r->d) */
71   Map noupdate;                         /* don't try to update these
72                                            installed solvables */
73
74   Id *watches;                          /* Array of rule offsets
75                                          * watches has nsolvables*2 entries and is addressed from the middle
76                                          * middle-solvable : decision to conflict, offset point to linked-list of rules
77                                          * middle+solvable : decision to install: offset point to linked-list of rules
78                                          */
79
80   Queue ruletojob;
81
82   /* our decisions: */
83   Queue decisionq;
84   Queue decisionq_why;                  /* index of rule, Offset into rules */
85   Id *decisionmap;                      /* map for all available solvables, > 0: level of decision when installed, < 0 level of decision when conflict */
86
87   /* learnt rule history */
88   Queue learnt_why;
89   Queue learnt_pool;
90
91   Queue branches;
92   int (*solution_callback)(struct solver *solv, void *data);
93   void *solution_callback_data;
94
95   int propagate_index;
96
97   Queue problems;
98   Queue suggestions;                    /* suggested packages */
99
100   Map recommendsmap;                    /* recommended packages from decisionmap */
101   Map suggestsmap;                      /* suggested packages from decisionmap */
102   int recommends_index;                 /* recommended level */
103
104   Id *obsoletes;                        /* obsoletes for each installed solvable */
105   Id *obsoletes_data;                   /* data area for obsoletes */
106
107 } Solver;
108
109 /*
110  * queue commands
111  */
112
113 typedef enum {
114   SOLVCMD_NULL=0,
115   SOLVER_INSTALL_SOLVABLE,
116   SOLVER_ERASE_SOLVABLE,
117   SOLVER_INSTALL_SOLVABLE_NAME,
118   SOLVER_ERASE_SOLVABLE_NAME,
119   SOLVER_INSTALL_SOLVABLE_PROVIDES,
120   SOLVER_ERASE_SOLVABLE_PROVIDES,
121   SOLVER_INSTALL_SOLVABLE_UPDATE
122 } SolverCmd;
123
124 typedef enum {
125   SOLVER_PROBLEM_UPDATE_RULE,
126   SOLVER_PROBLEM_JOB_RULE,
127   SOLVER_PROBLEM_JOB_NOTHING_PROVIDES_DEP,
128   SOLVER_PROBLEM_NOT_INSTALLABLE,
129   SOLVER_PROBLEM_NOTHING_PROVIDES_DEP,
130   SOLVER_PROBLEM_SAME_NAME,
131   SOLVER_PROBLEM_PACKAGE_CONFLICT,
132   SOLVER_PROBLEM_PACKAGE_OBSOLETES,
133   SOLVER_PROBLEM_DEP_PROVIDERS_NOT_INSTALLABLE
134 } SolverProbleminfo;
135
136
137 extern Solver *solver_create(Pool *pool, Repo *installed);
138 extern void solver_free(Solver *solv);
139 extern void solver_solve(Solver *solv, Queue *job);
140 extern int solver_dep_installed(Solver *solv, Id dep);
141
142 extern Id solver_next_problem(Solver *solv, Id problem);
143 extern Id solver_next_solution(Solver *solv, Id problem, Id solution);
144 extern Id solver_next_solutionelement(Solver *solv, Id problem, Id solution, Id element, Id *p, Id *rp);
145 extern Id solver_findproblemrule(Solver *solv, Id problem);
146 extern SolverProbleminfo solver_problemruleinfo(Solver *solv, Queue *job, Id rid, Id *depp, Id *sourcep, Id *targetp);
147
148 Id *create_obsoletesmap(Solver *solv);
149
150 /* debug functions, do not use */
151 void printdecisions(Solver *solv);
152 void printsolutions(Solver *solv, Queue *job);
153
154
155 static inline int
156 solver_dep_fulfilled(Solver *solv, Id dep)
157 {
158   Pool *pool = solv->pool;
159   Id p, *pp;
160
161   if (ISRELDEP(dep))
162     {
163       Reldep *rd = GETRELDEP(pool, dep);
164       if (rd->flags == REL_AND)
165         {
166           if (!solver_dep_fulfilled(solv, rd->name))
167             return 0;
168           return solver_dep_fulfilled(solv, rd->evr);
169         }
170       if (rd->flags == REL_NAMESPACE && rd->name == NAMESPACE_INSTALLED)
171         return solver_dep_installed(solv, rd->evr);
172     }
173   FOR_PROVIDES(p, pp, dep)
174     {
175       if (solv->decisionmap[p] > 0)
176         return 1;
177     }
178   return 0;
179 }
180
181 static inline int
182 solver_is_supplementing(Solver *solv, Solvable *s)
183 {
184   Id sup, *supp;
185   if (!s->supplements && !s->freshens)
186     return 0;
187   if (s->supplements)
188     {
189       supp = s->repo->idarraydata + s->supplements;
190       while ((sup = *supp++) != 0)
191         if (solver_dep_fulfilled(solv, sup))
192           break;
193       if (!sup)
194         return 0;
195     }
196   if (s->freshens)
197     {
198       supp = s->repo->idarraydata + s->freshens;
199       while ((sup = *supp++) != 0)
200         if (solver_dep_fulfilled(solv, sup))
201           break;
202       if (!sup)
203         return 0;
204     }
205   return 1;
206 }
207
208 static inline int
209 solver_is_enhancing(Solver *solv, Solvable *s)
210 {
211   Id enh, *enhp;
212   if (!s->enhances)
213     return 0;
214   enhp = s->repo->idarraydata + s->enhances;
215   while ((enh = *enhp++) != 0)
216     if (solver_dep_fulfilled(solv, enh))
217       return 1;
218   return 0;
219 }
220
221 #endif /* SATSOLVER_SOLVER_H */