nix/libstore/misc.cc

   1 #include "misc.hh"
   2 #include "store-api.hh"
   3 #include "local-store.hh"
   4 #include "globals.hh"
   5
   6
   7 namespace nix {
   8
   9
  10 Derivation derivationFromPath(StoreAPI & store, const Path & drvPath)
  11 {
  12     assertStorePath(drvPath);
  13     store.ensurePath(drvPath);
  14     return readDerivation(drvPath);
  15 }
  16
  17
  18 void computeFSClosure(StoreAPI & store, const Path & path,
  19     PathSet & paths, bool flipDirection, bool includeOutputs, bool includeDerivers)
  20 {
  21     if (paths.find(path) != paths.end()) return;
  22     paths.insert(path);
  23
  24     PathSet edges;
  25
  26     if (flipDirection) {
  27         store.queryReferrers(path, edges);
  28
  29         if (includeOutputs) {
  30             PathSet derivers = store.queryValidDerivers(path);
  31             foreach (PathSet::iterator, i, derivers)
  32                 edges.insert(*i);
  33         }
  34
  35         if (includeDerivers && isDerivation(path)) {
  36             PathSet outputs = store.queryDerivationOutputs(path);
  37             foreach (PathSet::iterator, i, outputs)
  38                 if (store.isValidPath(*i) && store.queryDeriver(*i) == path)
  39                     edges.insert(*i);
  40         }
  41
  42     } else {
  43         store.queryReferences(path, edges);
  44
  45         if (includeOutputs && isDerivation(path)) {
  46             PathSet outputs = store.queryDerivationOutputs(path);
  47             foreach (PathSet::iterator, i, outputs)
  48                 if (store.isValidPath(*i)) edges.insert(*i);
  49         }
  50
  51         if (includeDerivers) {
  52             Path deriver = store.queryDeriver(path);
  53             if (store.isValidPath(deriver)) edges.insert(deriver);
  54         }
  55     }
  56
  57     foreach (PathSet::iterator, i, edges)
  58         computeFSClosure(store, *i, paths, flipDirection, includeOutputs, includeDerivers);
  59 }
  60
  61
  62 Path findOutput(const Derivation & drv, string id)
  63 {
  64     foreach (DerivationOutputs::const_iterator, i, drv.outputs)
  65         if (i->first == id) return i->second.path;
  66     throw Error(format("derivation has no output `%1%'") % id);
  67 }
  68
  69
  70 static void dfsVisit(StoreAPI & store, const PathSet & paths,
  71     const Path & path, PathSet & visited, Paths & sorted,
  72     PathSet & parents)
  73 {
  74     if (parents.find(path) != parents.end())
  75         throw BuildError(format("cycle detected in the references of `%1%'") % path);
  76
  77     if (visited.find(path) != visited.end()) return;
  78     visited.insert(path);
  79     parents.insert(path);
  80
  81     PathSet references;
  82     if (store.isValidPath(path))
  83         store.queryReferences(path, references);
  84
  85     foreach (PathSet::iterator, i, references)
  86         /* Don't traverse into paths that don't exist.  That can
  87            happen due to substitutes for non-existent paths. */
  88         if (*i != path && paths.find(*i) != paths.end())
  89             dfsVisit(store, paths, *i, visited, sorted, parents);
  90
  91     sorted.push_front(path);
  92     parents.erase(path);
  93 }
  94
  95
  96 Paths topoSortPaths(StoreAPI & store, const PathSet & paths)
  97 {
  98     Paths sorted;
  99     PathSet visited, parents;
 100     foreach (PathSet::const_iterator, i, paths)
 101         dfsVisit(store, paths, *i, visited, sorted, parents);
 102     return sorted;
 103 }
 104
 105
 106 }