lix/src/libstore/store.hh
Eelco Dolstra fa9259f5f5 * Simplify the substitute mechanism:
- Drop the store expression.  So now a substitute is just a
    command-line invocation (a program name + arguments).  If you
    register a substitute you are responsible for registering the
    expression that built it (if any) as a root of the garbage
    collector.
  - Drop the substitutes-rev DB table.
2004-12-20 13:43:32 +00:00

100 lines
2.9 KiB
C++

#ifndef __STORE_H
#define __STORE_H
#include <string>
#include "hash.hh"
#include "db.hh"
using namespace std;
/* A substitute is a program invocation that constructs some store
path (typically by fetching it from somewhere, e.g., from the
network). */
struct Substitute
{
/* Program to be executed to create the store path. Must be in
the output path of `storeExpr'. */
Path program;
/* Extra arguments to be passed to the program (the first argument
is the store path to be substituted). */
Strings args;
bool operator == (const Substitute & sub);
};
typedef list<Substitute> Substitutes;
/* Open the database environment. */
void openDB();
/* Create the required database tables. */
void initDB();
/* Get a transaction object. */
void createStoreTransaction(Transaction & txn);
/* Copy a path recursively. */
void copyPath(const Path & src, const Path & dst);
/* Register a successor. This function accepts a transaction handle
so that it can be enclosed in an atomic operation with calls to
registerValidPath(). This must be atomic, since if we register a
successor for a derivation without registering the paths built in
the derivation, we have a successor with dangling pointers, and if
we do it in reverse order, we can get an obstructed build (since to
rebuild the successor, the outputs paths must not exist). */
void registerSuccessor(const Transaction & txn,
const Path & srcPath, const Path & sucPath);
/* Remove a successor mapping. */
void unregisterSuccessor(const Path & srcPath);
/* Return the predecessors of the Nix expression stored at the given
path. */
bool querySuccessor(const Path & srcPath, Path & sucPath);
/* Return the predecessors of the Nix expression stored at the given
path. */
Paths queryPredecessors(const Path & sucPath);
/* Register a substitute. */
typedef list<pair<Path, Substitute> > SubstitutePairs;
void registerSubstitutes(const Transaction & txn,
const SubstitutePairs & subPairs);
/* Return the substitutes expression for the given path. */
Substitutes querySubstitutes(const Path & srcPath);
/* Deregister all substitutes. */
void clearSubstitutes();
/* Register the validity of a path. */
void registerValidPath(const Transaction & txn, const Path & path);
/* Throw an exception if `path' is not directly in the Nix store. */
void assertStorePath(const Path & path);
/* Checks whether a path is valid. */
bool isValidPath(const Path & path);
/* Copy the contents of a path to the store and register the validity
the resulting path. The resulting path is returned. */
Path addToStore(const Path & srcPath);
/* Like addToStore, but the path of the output is given, and the
contents written to the output path is a regular file containing
the given string. */
void addTextToStore(const Path & dstPath, const string & s);
/* Delete a value from the nixStore directory. */
void deleteFromStore(const Path & path);
void verifyStore();
#endif /* !__STORE_H */