lix/src/libstore/store.hh

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#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 substitute. */
void registerSubstitute(const Transaction & txn,
const Path & srcPath, const Substitute & sub);
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/* Return the substitutes for the given path. */
Substitutes querySubstitutes(const Transaction & txn, const Path & srcPath);
/* Deregister all substitutes. */
void clearSubstitutes();
/* Register the validity of a path, i.e., that `path' exists, that the
paths referenced by it exists, and in the case of an output path of
a derivation, that it has been produced by a succesful execution of
the derivation (or something equivalent). Also register the hash
of the file system contents of the path. The hash must be a
SHA-256 hash. */
void registerValidPath(const Transaction & txn,
const Path & path, const Hash & hash, const PathSet & references,
const Path & deriver);
/* Throw an exception if `path' is not directly in the Nix store. */
void assertStorePath(const Path & path);
bool isInStore(const Path & path);
bool isStorePath(const Path & path);
/* Chop off the parts after the top-level store name, e.g.,
/nix/store/abcd-foo/bar => /nix/store/abcd-foo. */
Path toStorePath(const Path & path);
/* "Fix", or canonicalise, the meta-data of the files in a store path
after it has been built. In particular:
- the last modification date on each file is set to 0 (i.e.,
00:00:00 1/1/1970 UTC)
- the permissions are set of 444 or 555 (i.e., read-only with or
without execute permission; setuid bits etc. are cleared)
- the owner and group are set to the Nix user and group, if we're
in a setuid Nix installation. */
void canonicalisePathMetaData(const Path & path);
/* Checks whether a path is valid. */
bool isValidPath(const Path & path);
/* Sets the set of outgoing FS references for a store path. Use with
care! */
void setReferences(const Transaction & txn, const Path & storePath,
const PathSet & references);
/* Queries the set of outgoing FS references for a store path. The
result is not cleared. */
void queryReferences(const Transaction & txn,
const Path & storePath, PathSet & references);
/* Queries the set of incoming FS references for a store path. The
result is not cleared. */
void queryReferers(const Transaction & txn,
const Path & storePath, PathSet & referers);
/* Sets the deriver of a store path. Use with care! */
void setDeriver(const Transaction & txn, const Path & storePath,
const Path & deriver);
/* Query the deriver of a store path. Return the empty string if no
deriver has been set. */
Path queryDeriver(const Transaction & txn, const Path & storePath);
/* Constructs a unique store path name. */
Path makeStorePath(const string & type,
* Removed the `id' attribute hack. * Formalise the notion of fixed-output derivations, i.e., derivations for which a cryptographic hash of the output is known in advance. Changes to such derivations should not propagate upwards through the dependency graph. Previously this was done by specifying the hash component of the output path through the `id' attribute, but this is insecure since you can lie about it (i.e., you can specify any hash and then produce a completely different output). Now the responsibility for checking the output is moved from the builder to Nix itself. A fixed-output derivation can be created by specifying the `outputHash' and `outputHashAlgo' attributes, the latter taking values `md5', `sha1', and `sha256', and the former specifying the actual hash in hexadecimal or in base-32 (auto-detected by looking at the length of the attribute value). MD5 is included for compatibility but should be considered deprecated. * Removed the `drvPath' pseudo-attribute in derivation results. It's no longer necessary. * Cleaned up the support for multiple output paths in derivation store expressions. Each output now has a unique identifier (e.g., `out', `devel', `docs'). Previously there was no way to tell output paths apart at the store expression level. * `nix-hash' now has a flag `--base32' to specify that the hash should be printed in base-32 notation. * `fetchurl' accepts parameters `sha256' and `sha1' in addition to `md5'. * `nix-prefetch-url' now prints out a SHA-1 hash in base-32. (TODO: a flag to specify the hash.)
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const Hash & hash, const string & suffix);
/* 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);
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/* Like addToStore, but the contents written to the output path is a
regular file containing the given string. */
Path addTextToStore(const string & suffix, const string & s,
const PathSet & references);
/* Delete a value from the nixStore directory. */
void deleteFromStore(const Path & path);
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void verifyStore();
#endif /* !__STORE_H */