nix-super/src/libstore/build/goal.hh
Andreas Rammhold a9cb1ca32c libstore: use set instead of list for waiter list
This replaces the O(n) search complexity in our insert code with a
lookup of O(log n). It also makes removing waitees easier as we can use
the extract method provided by the set class.
2021-08-08 14:05:38 +02:00

109 lines
2.6 KiB
C++

#pragma once
#include "types.hh"
#include "store-api.hh"
namespace nix {
/* Forward definition. */
struct Goal;
class Worker;
/* A pointer to a goal. */
typedef std::shared_ptr<Goal> GoalPtr;
typedef std::weak_ptr<Goal> WeakGoalPtr;
struct CompareGoalPtrs {
bool operator() (const GoalPtr & a, const GoalPtr & b) const;
};
/* Set of goals. */
typedef set<GoalPtr, CompareGoalPtrs> Goals;
typedef set<WeakGoalPtr, std::owner_less<WeakGoalPtr>> WeakGoals;
/* A map of paths to goals (and the other way around). */
typedef std::map<StorePath, WeakGoalPtr> WeakGoalMap;
struct Goal : public std::enable_shared_from_this<Goal>
{
typedef enum {ecBusy, ecSuccess, ecFailed, ecNoSubstituters, ecIncompleteClosure} ExitCode;
/* Backlink to the worker. */
Worker & worker;
/* Goals that this goal is waiting for. */
Goals waitees;
/* Goals waiting for this one to finish. Must use weak pointers
here to prevent cycles. */
WeakGoals waiters;
/* Number of goals we are/were waiting for that have failed. */
unsigned int nrFailed;
/* Number of substitution goals we are/were waiting for that
failed because there are no substituters. */
unsigned int nrNoSubstituters;
/* Number of substitution goals we are/were waiting for that
failed because they had unsubstitutable references. */
unsigned int nrIncompleteClosure;
/* Name of this goal for debugging purposes. */
string name;
/* Whether the goal is finished. */
ExitCode exitCode;
/* Exception containing an error message, if any. */
std::optional<Error> ex;
Goal(Worker & worker) : worker(worker)
{
nrFailed = nrNoSubstituters = nrIncompleteClosure = 0;
exitCode = ecBusy;
}
virtual ~Goal()
{
trace("goal destroyed");
}
virtual void work() = 0;
void addWaitee(GoalPtr waitee);
virtual void waiteeDone(GoalPtr waitee, ExitCode result);
virtual void handleChildOutput(int fd, const string & data)
{
abort();
}
virtual void handleEOF(int fd)
{
abort();
}
void trace(const FormatOrString & fs);
string getName()
{
return name;
}
/* Callback in case of a timeout. It should wake up its waiters,
get rid of any running child processes that are being monitored
by the worker (important!), etc. */
virtual void timedOut(Error && ex) = 0;
virtual string key() = 0;
void amDone(ExitCode result, std::optional<Error> ex = {});
virtual void cleanup() { }
};
void addToWeakGoals(WeakGoals & goals, GoalPtr p);
}