nix-super/src/fstate.hh
Eelco Dolstra 249988a787 * Allow the output/expression id to be forced to a certain
value; this potentially dangerous feature enables better 
  sharing for those paths for which the content is known in 
  advance (e.g., because a content hash is given).
* Fast builds: if we can expand all output paths of a derive 
  expression, we don't have to build.
2003-07-21 20:07:12 +00:00

75 lines
1.3 KiB
C++

#ifndef __FSTATE_H
#define __FSTATE_H
extern "C" {
#include <aterm2.h>
}
#include "store.hh"
/* Abstract syntax of fstate-expressions. */
typedef list<FSId> FSIds;
struct SliceElem
{
string path;
FSId id;
FSIds refs;
};
typedef list<SliceElem> SliceElems;
struct Slice
{
FSIds roots;
SliceElems elems;
};
typedef pair<string, FSId> DeriveOutput;
typedef pair<string, string> StringPair;
typedef list<DeriveOutput> DeriveOutputs;
typedef list<StringPair> StringPairs;
struct Derive
{
DeriveOutputs outputs;
FSIds inputs;
string builder;
string platform;
StringPairs env;
};
struct FState
{
enum { fsSlice, fsDerive } type;
Slice slice;
Derive derive;
};
/* Return a canonical textual representation of an expression. */
string printTerm(ATerm t);
/* Throw an exception with an error message containing the given
aterm. */
Error badTerm(const format & f, ATerm t);
/* Hash an aterm. */
Hash hashTerm(ATerm t);
/* Read an aterm from disk, given its id. */
ATerm termFromId(const FSId & id);
/* Write an aterm to the Nix store directory, and return its hash. */
FSId writeTerm(ATerm t, const string & suffix, FSId id = FSId());
/* Parse an fstate-expression. */
FState parseFState(ATerm t);
/* Parse an fstate-expression. */
ATerm unparseFState(const FState & fs);
#endif /* !__FSTATE_H */