/** \ingroup rpmts * \file lib/depends.c */ #include "system.h" #include #include #include /* XXX rpmExpand("%{_dependency_whiteout */ #include #include #include #include "lib/rpmte_internal.h" /* XXX tsortInfo_s */ #include "lib/rpmts_internal.h" #include "debug.h" /* * Strongly Connected Components * set of packages (indirectly) requiering each other */ struct scc_s { int count; /* # of external requires this SCC has */ /* int qcnt; # of external requires pointing to this SCC */ int size; /* # of members */ tsortInfo * members; }; typedef struct scc_s * scc; struct relation_s { tsortInfo rel_suc; // pkg requiring this package rpmsenseFlags rel_flags; // accumulated flags of the requirements struct relation_s * rel_next; }; typedef struct relation_s * relation; struct tsortInfo_s { rpmte te; int tsi_count; // #pkgs this pkg requires int tsi_qcnt; // #pkgs requiring this package int tsi_reqx; // requires Idx/mark as (queued/loop) struct relation_s * tsi_relations; struct relation_s * tsi_forward_relations; tsortInfo tsi_suc; // used for queuing (addQ) int tsi_SccIdx; // # of the SCC the node belongs to // (1 for trivial SCCs) int tsi_SccLowlink; // used for SCC detection }; struct badDeps_s { char * pname; const char * qname; }; static int badDepsInitialized = 0; static struct badDeps_s * badDeps = NULL; /** */ static void freeBadDeps(void) { if (badDeps) { struct badDeps_s * bdp; /* bdp->qname is a pointer to pname so doesn't need freeing */ for (bdp = badDeps; bdp->pname != NULL && bdp->qname != NULL; bdp++) bdp->pname = _free(bdp->pname); badDeps = _free(badDeps); } badDepsInitialized = 0; } /** * Check for dependency relations to be ignored. * * @param ts transaction set * @param p successor element (i.e. with Requires: ) * @param q predecessor element (i.e. with Provides: ) * @return 1 if dependency is to be ignored. */ static int ignoreDep(const rpmts ts, const rpmte p, const rpmte q) { struct badDeps_s * bdp; if (!badDepsInitialized) { char * s = rpmExpand("%{?_dependency_whiteout}", NULL); const char ** av = NULL; int msglvl = (rpmtsFlags(ts) & RPMTRANS_FLAG_DEPLOOPS) ? RPMLOG_WARNING : RPMLOG_DEBUG; int ac = 0; int i; if (s != NULL && *s != '\0' && !(i = poptParseArgvString(s, &ac, (const char ***)&av)) && ac > 0 && av != NULL) { bdp = badDeps = xcalloc(ac+1, sizeof(*badDeps)); for (i = 0; i < ac; i++, bdp++) { char * pname, * qname; if (av[i] == NULL) break; pname = xstrdup(av[i]); if ((qname = strchr(pname, '>')) != NULL) *qname++ = '\0'; bdp->pname = pname; bdp->qname = qname; rpmlog(msglvl, _("ignore package name relation(s) [%d]\t%s -> %s\n"), i, bdp->pname, (bdp->qname ? bdp->qname : "???")); } bdp->pname = NULL; bdp->qname = NULL; } av = _free(av); s = _free(s); badDepsInitialized++; } if (badDeps != NULL) for (bdp = badDeps; bdp->pname != NULL && bdp->qname != NULL; bdp++) { if (rstreq(rpmteN(p), bdp->pname) && rstreq(rpmteN(q), bdp->qname)) return 1; } return 0; } static void rpmTSIFree(tsortInfo tsi) { relation rel; while (tsi->tsi_relations != NULL) { rel = tsi->tsi_relations; tsi->tsi_relations = tsi->tsi_relations->rel_next; rel = _free(rel); } while (tsi->tsi_forward_relations != NULL) { rel = tsi->tsi_forward_relations; tsi->tsi_forward_relations = \ tsi->tsi_forward_relations->rel_next; rel = _free(rel); } } static inline int addSingleRelation(rpmte p, rpmte q, rpmsenseFlags dsflags) { struct tsortInfo_s *tsi_p, *tsi_q; relation rel; rpmElementType teType = rpmteType(p); rpmsenseFlags flags; /* Avoid deps outside this transaction and self dependencies */ if (q == NULL || q == p) return 0; /* Erasures are reversed installs. */ if (teType == TR_REMOVED) { rpmte r = p; p = q; q = r; flags = isErasePreReq(dsflags); } else { flags = isInstallPreReq(dsflags); } /* map legacy prereq to pre/preun as needed */ if (isLegacyPreReq(dsflags)) { flags |= (teType == TR_ADDED) ? RPMSENSE_SCRIPT_PRE : RPMSENSE_SCRIPT_PREUN; } tsi_p = rpmteTSI(p); tsi_q = rpmteTSI(q); /* if relation got already added just update the flags */ if (tsi_q->tsi_relations && tsi_q->tsi_relations->rel_suc == tsi_p) { tsi_q->tsi_relations->rel_flags |= flags; tsi_p->tsi_forward_relations->rel_flags |= flags; return 0; } /* Record next "q <- p" relation (i.e. "p" requires "q"). */ if (p != q) { /* bump p predecessor count */ tsi_p->tsi_count++; } rel = xcalloc(1, sizeof(*rel)); rel->rel_suc = tsi_p; rel->rel_flags = flags; rel->rel_next = tsi_q->tsi_relations; tsi_q->tsi_relations = rel; if (p != q) { /* bump q successor count */ tsi_q->tsi_qcnt++; } rel = xcalloc(1, sizeof(*rel)); rel->rel_suc = tsi_q; rel->rel_flags = flags; rel->rel_next = tsi_p->tsi_forward_relations; tsi_p->tsi_forward_relations = rel; return 0; } /** * Record next "q <- p" relation (i.e. "p" requires "q"). * @param ts transaction set * @param p predecessor (i.e. package that "Requires: q") * @param requires relation * @return 0 always */ static inline int addRelation(rpmts ts, rpmal al, rpmte p, rpmds requires) { rpmte q; rpmsenseFlags dsflags; dsflags = rpmdsFlags(requires); /* Avoid dependendencies which are not relevant for ordering */ if (dsflags & (RPMSENSE_RPMLIB|RPMSENSE_CONFIG|RPMSENSE_PRETRANS)) return 0; q = rpmalSatisfiesDepend(al, requires); /* Avoid deps outside this transaction and self dependencies */ if (q == NULL || q == p) return 0; /* Avoid certain dependency relations. */ if (ignoreDep(ts, p, q)) return 0; addSingleRelation(p, q, dsflags); return 0; } /* * Collections might have special ordering requirements. Notably * sepolicy collection requires having all the bits in the collection * close to each other. We try to ensure this by creating a strongly * connected component of such "grouped" collections, by introducing * an artificial relation loop across the all its members. */ static int addCollRelations(rpmal al, rpmte p, ARGV_t *seenColls) { ARGV_const_t qcolls; for (qcolls = rpmteCollections(p); qcolls && *qcolls; qcolls++) { char * flags; if (argvSearch(*seenColls, *qcolls, NULL)) continue; flags = rstrscat(NULL, "%{__collection_", *qcolls, "_flags}", NULL); if (rpmExpandNumeric(flags) & 0x1) { rpmte *tes = rpmalAllInCollection(al, *qcolls); for (rpmte *te = tes; te && *te; te++) { rpmte next = (*(te + 1) != NULL) ? *(te + 1) : *tes; addSingleRelation(*te, next, RPMSENSE_ANY); } _free(tes); } free(flags); argvAdd(seenColls, *qcolls); argvSort(*seenColls, NULL); } return 0; } /** * Add element to list sorting by tsi_qcnt. * @param p new element * @retval qp address of first element * @retval rp address of last element * @param prefcolor */ static void addQ(tsortInfo p, tsortInfo * qp, tsortInfo * rp, rpm_color_t prefcolor) { tsortInfo q, qprev; /* Mark the package as queued. */ p->tsi_reqx = 1; if ((*rp) == NULL) { /* 1st element */ /* FIX: double indirection */ (*rp) = (*qp) = p; return; } /* Find location in queue using metric tsi_qcnt. */ for (qprev = NULL, q = (*qp); q != NULL; qprev = q, q = q->tsi_suc) { /* XXX Insure preferred color first. */ if (rpmteColor(p->te) != prefcolor && rpmteColor(p->te) != rpmteColor(q->te)) continue; if (q->tsi_qcnt <= p->tsi_qcnt) break; } if (qprev == NULL) { /* insert at beginning of list */ p->tsi_suc = q; (*qp) = p; /* new head */ } else if (q == NULL) { /* insert at end of list */ qprev->tsi_suc = p; (*rp) = p; /* new tail */ } else { /* insert between qprev and q */ p->tsi_suc = q; qprev->tsi_suc = p; } } typedef struct sccData_s { int index; /* DFS node number counter */ tsortInfo *stack; /* Stack of nodes */ int stackcnt; /* Stack top counter */ scc SCCs; /* Array of SCC's found */ int sccCnt; /* Number of SCC's found */ } * sccData; static void tarjan(sccData sd, tsortInfo tsi) { tsortInfo tsi_q; relation rel; /* use negative index numbers */ sd->index--; /* Set the depth index for p */ tsi->tsi_SccIdx = sd->index; tsi->tsi_SccLowlink = sd->index; sd->stack[sd->stackcnt++] = tsi; /* Push p on the stack */ for (rel=tsi->tsi_relations; rel != NULL; rel=rel->rel_next) { /* Consider successors of p */ tsi_q = rel->rel_suc; if (tsi_q->tsi_SccIdx > 0) /* Ignore already found SCCs */ continue; if (tsi_q->tsi_SccIdx == 0){ /* Was successor q not yet visited? */ tarjan(sd, tsi_q); /* Recurse */ /* negative index numers: use max as it is closer to 0 */ tsi->tsi_SccLowlink = ( tsi->tsi_SccLowlink > tsi_q->tsi_SccLowlink ? tsi->tsi_SccLowlink : tsi_q->tsi_SccLowlink); } else { tsi->tsi_SccLowlink = ( tsi->tsi_SccLowlink > tsi_q->tsi_SccIdx ? tsi->tsi_SccLowlink : tsi_q->tsi_SccIdx); } } if (tsi->tsi_SccLowlink == tsi->tsi_SccIdx) { /* v is the root of an SCC? */ if (sd->stack[sd->stackcnt-1] == tsi) { /* ignore trivial SCCs */ tsi_q = sd->stack[--sd->stackcnt]; tsi_q->tsi_SccIdx = 1; } else { int stackIdx = sd->stackcnt; do { tsi_q = sd->stack[--stackIdx]; tsi_q->tsi_SccIdx = sd->sccCnt; } while (tsi_q != tsi); stackIdx = sd->stackcnt; do { tsi_q = sd->stack[--stackIdx]; /* Calculate count for the SCC */ sd->SCCs[sd->sccCnt].count += tsi_q->tsi_count; /* Subtract internal relations */ for (rel=tsi_q->tsi_relations; rel != NULL; rel=rel->rel_next) { if (rel->rel_suc != tsi_q && rel->rel_suc->tsi_SccIdx == sd->sccCnt) sd->SCCs[sd->sccCnt].count--; } } while (tsi_q != tsi); sd->SCCs[sd->sccCnt].size = sd->stackcnt - stackIdx; /* copy members */ sd->SCCs[sd->sccCnt].members = xcalloc(sd->SCCs[sd->sccCnt].size, sizeof(tsortInfo)); memcpy(sd->SCCs[sd->sccCnt].members, sd->stack + stackIdx, sd->SCCs[sd->sccCnt].size * sizeof(tsortInfo)); sd->stackcnt = stackIdx; sd->sccCnt++; } } } /* Search for SCCs and return an array last entry has a .size of 0 */ static scc detectSCCs(tsortInfo orderInfo, int nelem, int debugloops) { /* Set up data structures needed for the tarjan algorithm */ scc SCCs = xcalloc(nelem+3, sizeof(*SCCs)); tsortInfo *stack = xcalloc(nelem, sizeof(*stack)); struct sccData_s sd = { 0, stack, 0, SCCs, 2 }; for (int i = 0; i < nelem; i++) { tsortInfo tsi = &orderInfo[i]; /* Start a DFS at each node */ if (tsi->tsi_SccIdx == 0) tarjan(&sd, tsi); } free(stack); SCCs = xrealloc(SCCs, (sd.sccCnt+1)*sizeof(struct scc_s)); /* Debug output */ if (sd.sccCnt > 2) { int msglvl = debugloops ? RPMLOG_WARNING : RPMLOG_DEBUG; rpmlog(msglvl, "%i Strongly Connected Components\n", sd.sccCnt-2); for (int i = 2; i < sd.sccCnt; i++) { rpmlog(msglvl, "SCC #%i: requires %i packages\n", i, SCCs[i].count); /* loop over members */ for (int j = 0; j < SCCs[i].size; j++) { tsortInfo member = SCCs[i].members[j]; rpmlog(msglvl, "\t%s\n", rpmteNEVRA(member->te)); /* show relations between members */ relation rel = member->tsi_forward_relations; for (; rel != NULL; rel=rel->rel_next) { if (rel->rel_suc->tsi_SccIdx!=i) continue; rpmlog(msglvl, "\t\t%s %s\n", rel->rel_flags ? "=>" : "->", rpmteNEVRA(rel->rel_suc->te)); } } } } return SCCs; } static void collectTE(rpm_color_t prefcolor, tsortInfo q, rpmte * newOrder, int * newOrderCount, scc SCCs, tsortInfo * queue_end, tsortInfo * outer_queue, tsortInfo * outer_queue_end) { char deptypechar = (rpmteType(q->te) == TR_REMOVED ? '-' : '+'); if (rpmIsDebug()) { int depth = 1; /* figure depth in tree for nice formatting */ for (rpmte p = q->te; (p = rpmteParent(p)); depth++) {} rpmlog(RPMLOG_DEBUG, "%5d%5d%5d%5d %*s%c%s\n", *newOrderCount, q->tsi_count, q->tsi_qcnt, depth, (2 * depth), "", deptypechar, rpmteNEVRA(q->te)); } newOrder[*newOrderCount] = q->te; (*newOrderCount)++; /* T6. Erase relations. */ for (relation rel = q->tsi_relations; rel != NULL; rel = rel->rel_next) { tsortInfo p = rel->rel_suc; /* ignore already collected packages */ if (p->tsi_SccIdx == 0) continue; if (p == q) continue; if (p && (--p->tsi_count) == 0) { (void) rpmteSetParent(p->te, q->te); if (q->tsi_SccIdx > 1 && q->tsi_SccIdx != p->tsi_SccIdx) { /* Relation point outside of this SCC: add to outside queue */ assert(outer_queue != NULL && outer_queue_end != NULL); addQ(p, outer_queue, outer_queue_end, prefcolor); } else { addQ(p, &q->tsi_suc, queue_end, prefcolor); } } if (p && p->tsi_SccIdx > 1 && p->tsi_SccIdx != q->tsi_SccIdx) { if (--SCCs[p->tsi_SccIdx].count == 0) { /* New SCC is ready, add this package as representative */ (void) rpmteSetParent(p->te, q->te); if (outer_queue != NULL) { addQ(p, outer_queue, outer_queue_end, prefcolor); } else { addQ(p, &q->tsi_suc, queue_end, prefcolor); } } } } q->tsi_SccIdx = 0; } static void collectSCC(rpm_color_t prefcolor, tsortInfo p_tsi, rpmte * newOrder, int * newOrderCount, scc SCCs, tsortInfo * queue_end) { int sccNr = p_tsi->tsi_SccIdx; struct scc_s SCC = SCCs[sccNr]; int i; int start, end; relation rel; /* remove p from the outer queue */ tsortInfo outer_queue_start = p_tsi->tsi_suc; p_tsi->tsi_suc = NULL; /* * Run a multi source Dijkstra's algorithm to find relations * that can be zapped with least danger to pre reqs. * As weight of the edges is always 1 it is not necessary to * sort the vertices by distance as the queue gets them * already in order */ /* can use a simple queue as edge weights are always 1 */ tsortInfo * queue = xmalloc((SCC.size+1) * sizeof(*queue)); /* * Find packages that are prerequired and use them as * starting points for the Dijkstra algorithm */ start = end = 0; for (i = 0; i < SCC.size; i++) { tsortInfo tsi = SCC.members[i]; tsi->tsi_SccLowlink = INT_MAX; for (rel=tsi->tsi_forward_relations; rel != NULL; rel=rel->rel_next) { if (rel->rel_flags && rel->rel_suc->tsi_SccIdx == sccNr) { if (rel->rel_suc != tsi) { tsi->tsi_SccLowlink = 0; queue[end++] = tsi; } else { tsi->tsi_SccLowlink = INT_MAX/2; } break; } } } if (start == end) { /* no regular prereqs; add self prereqs to queue */ for (i = 0; i < SCC.size; i++) { tsortInfo tsi = SCC.members[i]; if (tsi->tsi_SccLowlink != INT_MAX) { queue[end++] = tsi; } } } /* Do Dijkstra */ while (start != end) { tsortInfo tsi = queue[start++]; for (rel=tsi->tsi_forward_relations; rel != NULL; rel=rel->rel_next) { tsortInfo next_tsi = rel->rel_suc; if (next_tsi->tsi_SccIdx != sccNr) continue; if (next_tsi->tsi_SccLowlink > tsi->tsi_SccLowlink+1) { next_tsi->tsi_SccLowlink = tsi->tsi_SccLowlink + 1; queue[end++] = rel->rel_suc; } } } queue = _free(queue); while (1) { tsortInfo best = NULL; tsortInfo inner_queue_start, inner_queue_end; int best_score = 0; /* select best candidate to start with */ for (int i = 0; i < SCC.size; i++) { tsortInfo tsi = SCC.members[i]; if (tsi->tsi_SccIdx == 0) /* package already collected */ continue; if (tsi->tsi_SccLowlink >= best_score) { best = tsi; best_score = tsi->tsi_SccLowlink; } } if (best == NULL) /* done */ break; /* collect best candidate and all packages that get freed */ inner_queue_start = inner_queue_end = NULL; addQ(best, &inner_queue_start, &inner_queue_end, prefcolor); for (; inner_queue_start != NULL; inner_queue_start = inner_queue_start->tsi_suc) { /* Mark the package as unqueued. */ inner_queue_start->tsi_reqx = 0; collectTE(prefcolor, inner_queue_start, newOrder, newOrderCount, SCCs, &inner_queue_end, &outer_queue_start, queue_end); } } /* restore outer queue */ p_tsi->tsi_suc = outer_queue_start; } int rpmtsOrder(rpmts ts) { tsMembers tsmem = rpmtsMembers(ts); rpm_color_t prefcolor = rpmtsPrefColor(ts); rpmtsi pi; rpmte p; tsortInfo q, r; rpmte * newOrder; int newOrderCount = 0; int rc; rpmal erasedPackages = rpmalCreate(5, rpmtsColor(ts), prefcolor); scc SCCs; int nelem = rpmtsNElements(ts); tsortInfo sortInfo = xcalloc(nelem, sizeof(struct tsortInfo_s)); ARGV_t seenColls = NULL; (void) rpmswEnter(rpmtsOp(ts, RPMTS_OP_ORDER), 0); /* Create erased package index. */ pi = rpmtsiInit(ts); while ((p = rpmtsiNext(pi, TR_REMOVED)) != NULL) { rpmalAdd(erasedPackages, p); } pi = rpmtsiFree(pi); for (int i = 0; i < nelem; i++) { sortInfo[i].te = tsmem->order[i]; rpmteSetTSI(tsmem->order[i], &sortInfo[i]); } /* Record relations. */ rpmlog(RPMLOG_DEBUG, "========== recording tsort relations\n"); pi = rpmtsiInit(ts); while ((p = rpmtsiNext(pi, 0)) != NULL) { rpmal al = (rpmteType(p) == TR_REMOVED) ? erasedPackages : tsmem->addedPackages; rpmds requires = rpmdsInit(rpmteDS(p, RPMTAG_REQUIRENAME)); while (rpmdsNext(requires) >= 0) { /* Record next "q <- p" relation (i.e. "p" requires "q"). */ (void) addRelation(ts, al, p, requires); } addCollRelations(al, p, &seenColls); } seenColls = argvFree(seenColls); pi = rpmtsiFree(pi); newOrder = xcalloc(tsmem->orderCount, sizeof(*newOrder)); SCCs = detectSCCs(sortInfo, nelem, (rpmtsFlags(ts) & RPMTRANS_FLAG_DEPLOOPS)); rpmlog(RPMLOG_DEBUG, "========== tsorting packages (order, #predecessors, #succesors, depth)\n"); for (int i = 0; i < 2; i++) { /* Do two separate runs: installs first - then erases */ int oType = !i ? TR_ADDED : TR_REMOVED; q = r = NULL; /* Scan for zeroes and add them to the queue */ for (int e = 0; e < nelem; e++) { tsortInfo p = &sortInfo[e]; if (rpmteType(p->te) != oType) continue; if (p->tsi_count != 0) continue; p->tsi_suc = NULL; addQ(p, &q, &r, prefcolor); } /* Add one member of each leaf SCC */ for (int i = 2; SCCs[i].members != NULL; i++) { tsortInfo member = SCCs[i].members[0]; if (SCCs[i].count == 0 && rpmteType(member->te) == oType) { addQ(member, &q, &r, prefcolor); } } while (q != NULL) { /* Mark the package as unqueued. */ q->tsi_reqx = 0; if (q->tsi_SccIdx > 1) { collectSCC(prefcolor, q, newOrder, &newOrderCount, SCCs, &r); } else { collectTE(prefcolor, q, newOrder, &newOrderCount, SCCs, &r, NULL, NULL); } q = q->tsi_suc; } } /* Clean up tsort data */ for (int i = 0; i < nelem; i++) { rpmteSetTSI(tsmem->order[i], NULL); rpmTSIFree(&sortInfo[i]); } free(sortInfo); assert(newOrderCount == tsmem->orderCount); tsmem->order = _free(tsmem->order); tsmem->order = newOrder; tsmem->orderAlloced = tsmem->orderCount; rc = 0; freeBadDeps(); for (int i = 2; SCCs[i].members != NULL; i++) { free(SCCs[i].members); } free(SCCs); rpmalFree(erasedPackages); (void) rpmswExit(rpmtsOp(ts, RPMTS_OP_ORDER), 0); return rc; }