nix-super/src/libstore/misc.cc
Eelco Dolstra 863dcff6c5 * Started removing closure store expressions, i.e., the explicit
representation of closures as ATerms in the Nix store.  Instead, the
  file system pointer graph is now stored in the Nix database.  This
  has many advantages:

  - It greatly simplifies the implementation (we can drop the notion
    of `successors', and so on).

  - It makes registering roots for the garbage collector much easier.
    Instead of specifying the closure expression as a root, you can
    simply specify the store path that must be retained as a root.
    This could not be done previously, since there was no way to find
    the closure store expression containing a given store path.
    
  - Better traceability: it is now possible to query what paths are
    referenced by a path, and what paths refer to a path.
2005-01-19 11:16:11 +00:00

90 lines
2.3 KiB
C++

#include "normalise.hh"
Derivation derivationFromPath(const Path & drvPath)
{
assertStorePath(drvPath);
ensurePath(drvPath);
ATerm t = ATreadFromNamedFile(drvPath.c_str());
if (!t) throw Error(format("cannot read aterm from `%1%'") % drvPath);
return parseDerivation(t);
}
void computeFSClosure(const Path & storePath,
PathSet & paths)
{
if (paths.find(storePath) != paths.end()) return;
paths.insert(storePath);
PathSet references;
queryReferences(storePath, references);
for (PathSet::iterator i = references.begin();
i != references.end(); ++i)
computeFSClosure(*i, paths);
}
#if 0
PathSet storeExprRoots(const Path & nePath)
{
PathSet paths;
StoreExpr ne = storeExprFromPath(nePath);
if (ne.type == StoreExpr::neClosure)
paths.insert(ne.closure.roots.begin(), ne.closure.roots.end());
else if (ne.type == StoreExpr::neDerivation)
for (DerivationOutputs::iterator i = ne.derivation.outputs.begin();
i != ne.derivation.outputs.end(); ++i)
paths.insert(i->second.path);
else abort();
return paths;
}
static void requisitesWorker(const Path & nePath,
bool includeExprs, bool includeSuccessors,
PathSet & paths, PathSet & doneSet)
{
checkInterrupt();
if (doneSet.find(nePath) != doneSet.end()) return;
doneSet.insert(nePath);
StoreExpr ne = storeExprFromPath(nePath);
if (ne.type == StoreExpr::neClosure)
for (ClosureElems::iterator i = ne.closure.elems.begin();
i != ne.closure.elems.end(); ++i)
paths.insert(i->first);
else if (ne.type == StoreExpr::neDerivation)
for (PathSet::iterator i = ne.derivation.inputs.begin();
i != ne.derivation.inputs.end(); ++i)
requisitesWorker(*i,
includeExprs, includeSuccessors, paths, doneSet);
else abort();
if (includeExprs) paths.insert(nePath);
Path nfPath;
if (includeSuccessors && querySuccessor(nePath, nfPath))
requisitesWorker(nfPath, includeExprs, includeSuccessors,
paths, doneSet);
}
PathSet storeExprRequisites(const Path & nePath,
bool includeExprs, bool includeSuccessors)
{
PathSet paths;
PathSet doneSet;
requisitesWorker(nePath, includeExprs, includeSuccessors,
paths, doneSet);
return paths;
}
#endif