guix-devel/nix/libstore/misc.cc

107 lines
2.9 KiB
C++

#include "misc.hh"
#include "store-api.hh"
#include "local-store.hh"
#include "globals.hh"
namespace nix {
Derivation derivationFromPath(StoreAPI & store, const Path & drvPath)
{
assertStorePath(drvPath);
store.ensurePath(drvPath);
return readDerivation(drvPath);
}
void computeFSClosure(StoreAPI & store, const Path & path,
PathSet & paths, bool flipDirection, bool includeOutputs, bool includeDerivers)
{
if (paths.find(path) != paths.end()) return;
paths.insert(path);
PathSet edges;
if (flipDirection) {
store.queryReferrers(path, edges);
if (includeOutputs) {
PathSet derivers = store.queryValidDerivers(path);
foreach (PathSet::iterator, i, derivers)
edges.insert(*i);
}
if (includeDerivers && isDerivation(path)) {
PathSet outputs = store.queryDerivationOutputs(path);
foreach (PathSet::iterator, i, outputs)
if (store.isValidPath(*i) && store.queryDeriver(*i) == path)
edges.insert(*i);
}
} else {
store.queryReferences(path, edges);
if (includeOutputs && isDerivation(path)) {
PathSet outputs = store.queryDerivationOutputs(path);
foreach (PathSet::iterator, i, outputs)
if (store.isValidPath(*i)) edges.insert(*i);
}
if (includeDerivers) {
Path deriver = store.queryDeriver(path);
if (store.isValidPath(deriver)) edges.insert(deriver);
}
}
foreach (PathSet::iterator, i, edges)
computeFSClosure(store, *i, paths, flipDirection, includeOutputs, includeDerivers);
}
Path findOutput(const Derivation & drv, string id)
{
foreach (DerivationOutputs::const_iterator, i, drv.outputs)
if (i->first == id) return i->second.path;
throw Error(format("derivation has no output `%1%'") % id);
}
static void dfsVisit(StoreAPI & store, const PathSet & paths,
const Path & path, PathSet & visited, Paths & sorted,
PathSet & parents)
{
if (parents.find(path) != parents.end())
throw BuildError(format("cycle detected in the references of `%1%'") % path);
if (visited.find(path) != visited.end()) return;
visited.insert(path);
parents.insert(path);
PathSet references;
if (store.isValidPath(path))
store.queryReferences(path, references);
foreach (PathSet::iterator, i, references)
/* Don't traverse into paths that don't exist. That can
happen due to substitutes for non-existent paths. */
if (*i != path && paths.find(*i) != paths.end())
dfsVisit(store, paths, *i, visited, sorted, parents);
sorted.push_front(path);
parents.erase(path);
}
Paths topoSortPaths(StoreAPI & store, const PathSet & paths)
{
Paths sorted;
PathSet visited, parents;
foreach (PathSet::const_iterator, i, paths)
dfsVisit(store, paths, *i, visited, sorted, parents);
return sorted;
}
}