lix/src/store.hh
Eelco Dolstra e877c69d78 * Substitutes now should produce a path with the same id as they are
substituting for (obvious, really).

* For greater efficiency, nix-pull/unnar will place the output in a
  path that is probably the same as what is actually needed, thus
  preventing a path copy.

* Even if a output id is given in a Fix package expression, ensure
  that the resulting Nix derive expression has a different id.  This
  is because Nix expressions that are semantically equivalent (i.e.,
  build the same result) might be different w.r.t. efficiency or
  divergence.  It is absolutely vital for the substitute mechanism
  that such expressions are not used interchangeably.
2003-07-22 15:15:15 +00:00

52 lines
1.4 KiB
C++

#ifndef __STORE_H
#define __STORE_H
#include <string>
#include "hash.hh"
using namespace std;
typedef Hash FSId;
typedef set<FSId> FSIdSet;
/* Copy a path recursively. */
void copyPath(string src, string dst);
/* Register a substitute. */
void registerSubstitute(const FSId & srcId, const FSId & subId);
/* Register a path keyed on its id. */
void registerPath(const string & path, const FSId & id);
/* Query the id of a path. */
bool queryPathId(const string & path, FSId & id);
/* Return a path whose contents have the given hash. If target is
not empty, ensure that such a path is realised in target (if
necessary by copying from another location). If prefix is not
empty, only return a path that is an descendent of prefix.
The list of pending ids are those that already being expanded.
This prevents infinite recursion for ids realised through a
substitute (since when we build the substitute, we would first try
to expand the id... kaboom!). */
string expandId(const FSId & id, const string & target = "",
const string & prefix = "/", FSIdSet pending = FSIdSet());
/* Copy a file to the nixStore directory and register it in dbRefs.
Return the hash code of the value. */
void addToStore(string srcPath, string & dstPath, FSId & id,
bool deterministicName = false);
/* Delete a value from the nixStore directory. */
void deleteFromStore(const string & path);
void verifyStore();
#endif /* !__STORE_H */