* Get rid of the substitutes database table (NIX-47). Instead, if we

  need any info on substitutable paths, we just call the substituters
  (such as download-using-manifests.pl) directly.  This means that
  it's no longer necessary for nix-pull to register substitutes or for
  nix-channel to clear them, which makes those operations much faster
  (NIX-95).  Also, we don't have to worry about keeping nix-pull
  manifests (in /nix/var/nix/manifests) and the database in sync with
  each other.

  The downside is that there is some overhead in calling an external
  program to get the substitutes info.  For instance, "nix-env -qas"
  takes a bit longer.

  Abolishing the substitutes table also makes the logic in
  local-store.cc simpler, as we don't need to store info for invalid
  paths.  On the downside, you cannot do things like "nix-store -qR"
  on a substitutable but invalid path (but nobody did that anyway).

* Never catch interrupts (the Interrupted exception).

1 files changed, 8 insertions, 17 deletions

diff --git a/src/libstore/local-store.hh b/src/libstore/local-store.hh
index 7c5cd2668405..ffcef60716bb 100644
--- a/src/libstore/local-store.hh
+++ b/src/libstore/local-store.hh
@@ -23,6 +23,10 @@ extern string drvsLogDir;
 
 class LocalStore : public StoreAPI
 {
+private:
+    bool substitutablePathsLoaded;
+    PathSet substitutablePaths;
+    
 public:
 
     /* Open the database environment.  If `reserveSpace' is true, make
@@ -41,8 +45,6 @@ public:
     
     bool isValidPath(const Path & path);
 
-    Substitutes querySubstitutes(const Path & srcPath);
-
     Hash queryPathHash(const Path & path);
 
     void queryReferences(const Path & path, PathSet & references);
@@ -51,6 +53,10 @@ public:
 
     Path queryDeriver(const Path & path);
     
+    PathSet querySubstitutablePaths();
+    
+    bool hasSubstitutes(const Path & path);
+    
     Path addToStore(const Path & srcPath, bool fixed = false,
         bool recursive = false, string hashAlgo = "",
         PathFilter & filter = defaultPathFilter);
@@ -86,13 +92,6 @@ void createStoreTransaction(Transaction & txn);
 /* Copy a path recursively. */
 void copyPath(const Path & src, const Path & dst);
 
-/* Register a substitute. */
-void registerSubstitute(const Transaction & txn,
-    const Path & srcPath, const Substitute & sub);
-
-/* Deregister all substitutes. */
-void clearSubstitutes();
-
 /* Register the validity of a path, i.e., that `path' exists, that the
    paths referenced by it exists, and in the case of an output path of
    a derivation, that it has been produced by a succesful execution of
@@ -103,14 +102,6 @@ void registerValidPath(const Transaction & txn,
     const Path & path, const Hash & hash, const PathSet & references,
     const Path & deriver);
 
-struct ValidPathInfo 
-{
-    Path path;
-    Path deriver;
-    Hash hash;
-    PathSet references;
-};
-
 typedef list<ValidPathInfo> ValidPathInfos;
 
 void registerValidPaths(const Transaction & txn,