lix/src/libstore/realisation.hh
regnat bab1cda0e6 Use the hash modulo in the derivation outputs
Rather than storing the derivation outputs as `drvPath!outputName` internally,
store them as `drvHashModulo!outputName` (or `outputHash!outputName` for
fixed-output derivations).

This makes the storage slightly more opaque, but enables an earlier
cutoff in cases where a fixed-output dependency changes (but keeps the
same output hash) − same as what we already do for input-addressed
derivations.
2020-12-11 21:17:23 +01:00

40 lines
956 B
C++

#pragma once
#include "path.hh"
#include <nlohmann/json_fwd.hpp>
namespace nix {
struct DrvOutput {
// The hash modulo of the derivation
Hash drvHash;
std::string outputName;
std::string to_string() const;
std::string strHash() const
{ return drvHash.to_string(Base16, true); }
static DrvOutput parse(const std::string &);
bool operator<(const DrvOutput& other) const { return to_pair() < other.to_pair(); }
bool operator==(const DrvOutput& other) const { return to_pair() == other.to_pair(); }
private:
// Just to make comparison operators easier to write
std::pair<Hash, std::string> to_pair() const
{ return std::make_pair(drvHash, outputName); }
};
struct Realisation {
DrvOutput id;
StorePath outPath;
nlohmann::json toJSON() const;
static Realisation fromJSON(const nlohmann::json& json, const std::string& whence);
};
typedef std::map<DrvOutput, Realisation> DrvOutputs;
}