daemon: Use 'Agent' to spawn 'guix substitute --query'.

* nix/libstore/local-store.hh (RunningSubstituter): Remove.
(LocalStore)[runningSubstituter]: Change to unique_ptr<Agent>.
[setSubstituterEnv, didSetSubstituterEnv]: Remove.
[getLineFromSubstituter, getIntLineFromSubstituter]: Take an 'Agent'.
* nix/libstore/local-store.cc (LocalStore::~LocalStore): Remove
reference to 'runningSubstituter'.
(LocalStore::setSubstituterEnv, LocalStore::startSubstituter): Remove.
(LocalStore::getLineFromSubstituter): Adjust to 'run' being an 'Agent'.
(LocalStore::querySubstitutablePaths): Spawn substituter agent if
needed.  Adjust to 'Agent' interface.
(LocalStore::querySubstitutablePathInfos): Likewise.
* nix/libstore/build.cc (SubstitutionGoal::tryToRun): Remove call to
'setSubstituterEnv' and add 'setenv' call for "_NIX_OPTIONS" instead.
(SubstitutionGoal::finished): Remove 'readLine' call for 'dummy'.
* guix/scripts/substitute.scm (%allow-unauthenticated-substitutes?):
Remove second argument to 'make-parameter'.
(process-query): Call 'warn-about-missing-authentication'
when (%allow-unauthenticated-substitutes?) is #t.
(guix-substitute): Wrap body in 'parameterize'.  Set 'guix-warning-port'
too.  No longer exit when 'substitute-urls' returns the empty list.  No
longer print newline initially.
* tests/substitute.scm (test-quit): Parameterize 'current-error-port' to
account for the port changes in 'guix-substitute'.

1 files changed, 3 insertions, 19 deletions

diff --git a/nix/libstore/local-store.hh b/nix/libstore/local-store.hh
index 2e48cf03e6..57d15bac7e 100644
--- a/nix/libstore/local-store.hh
+++ b/nix/libstore/local-store.hh
@@ -38,21 +38,11 @@ struct OptimiseStats
 };
 
 
-struct RunningSubstituter
-{
-    Pid pid;
-    AutoCloseFD to, from, error;
-    FdSource fromBuf;
-    bool disabled;
-    RunningSubstituter() : disabled(false) { };
-};
-
-
 class LocalStore : public StoreAPI
 {
 private:
     /* The currently running substituter or empty.  */
-    std::unique_ptr<RunningSubstituter> runningSubstituter;
+    std::unique_ptr<Agent> runningSubstituter;
 
     Path linksDir;
 
@@ -178,8 +168,6 @@ public:
 
     void markContentsGood(const Path & path);
 
-    void setSubstituterEnv();
-
     void createUser(const std::string & userName, uid_t userId);
 
 private:
@@ -213,8 +201,6 @@ private:
     /* Cache for pathContentsGood(). */
     std::map<Path, bool> pathContentsGoodCache;
 
-    bool didSetSubstituterEnv;
-
     /* The file to which we write our temporary roots. */
     Path fnTempRoots;
     AutoCloseFD fdTempRoots;
@@ -262,11 +248,9 @@ private:
 
     void removeUnusedLinks(const GCState & state);
 
-    void startSubstituter(RunningSubstituter & runningSubstituter);
-
-    string getLineFromSubstituter(RunningSubstituter & run);
+    string getLineFromSubstituter(Agent & run);
 
-    template<class T> T getIntLineFromSubstituter(RunningSubstituter & run);
+    template<class T> T getIntLineFromSubstituter(Agent & run);
 
     Path createTempDirInStore();