lix/src/libstore/build/substitution-goal.hh
Eelco Dolstra 8a29052cb2 PathSubstitutionGoal: Clean up pipe
If there were many top-level goals (which are not destroyed until the
very end), commands like

  $ nix copy --to 'ssh://localhost?remote-store=/tmp/nix' \
    /run/current-system --no-check-sigs --substitute-on-destination

could fail with "Too many open files". So now we do some explicit
cleanup from amDone(). It would be cleaner to separate goals from
their temporary internal state, but that would be a bigger refactor.
2021-04-07 12:21:31 +02:00

87 lines
2.2 KiB
C++

#pragma once
#include "lock.hh"
#include "store-api.hh"
#include "goal.hh"
namespace nix {
class Worker;
struct PathSubstitutionGoal : public Goal
{
/* The store path that should be realised through a substitute. */
StorePath storePath;
/* The path the substituter refers to the path as. This will be
different when the stores have different names. */
std::optional<StorePath> subPath;
/* The remaining substituters. */
std::list<ref<Store>> subs;
/* The current substituter. */
std::shared_ptr<Store> sub;
/* Whether a substituter failed. */
bool substituterFailed = false;
/* Path info returned by the substituter's query info operation. */
std::shared_ptr<const ValidPathInfo> info;
/* Pipe for the substituter's standard output. */
Pipe outPipe;
/* The substituter thread. */
std::thread thr;
std::promise<void> promise;
/* Whether to try to repair a valid path. */
RepairFlag repair;
/* Location where we're downloading the substitute. Differs from
storePath when doing a repair. */
Path destPath;
std::unique_ptr<MaintainCount<uint64_t>> maintainExpectedSubstitutions,
maintainRunningSubstitutions, maintainExpectedNar, maintainExpectedDownload;
typedef void (PathSubstitutionGoal::*GoalState)();
GoalState state;
/* Content address for recomputing store path */
std::optional<ContentAddress> ca;
public:
PathSubstitutionGoal(const StorePath & storePath, Worker & worker, RepairFlag repair = NoRepair, std::optional<ContentAddress> ca = std::nullopt);
~PathSubstitutionGoal();
void timedOut(Error && ex) override { abort(); };
string key() override
{
/* "a$" ensures substitution goals happen before derivation
goals. */
return "a$" + std::string(storePath.name()) + "$" + worker.store.printStorePath(storePath);
}
void work() override;
/* The states. */
void init();
void tryNext();
void gotInfo();
void referencesValid();
void tryToRun();
void finished();
/* Callback used by the worker to write to the log. */
void handleChildOutput(int fd, const string & data) override;
void handleEOF(int fd) override;
void cleanup() override;
};
}