* Substitute fixes.

corepkgs/fetchurl/fetchurl.sh

@@ -4,7 +4,9 @@ echo "downloading $url into $out..."
 wget "$url" -O "$out" || exit 1
 
 actual=$(md5sum -b $out | cut -c1-32)
+if ! test "$md5" == "ignore"; then
     if ! test "$actual" == "$md5"; then
 	echo "hash is $actual, expected $md5"
 	exit 1
     fi
+fi

corepkgs/nar/nar.sh

@@ -1,3 +1,3 @@
 #! /bin/sh
 
-/tmp/nix/bin/nix --dump --file "$path" | bzip2 > $out || exit 1
+/nix/bin/nix --dump --file "$path" | bzip2 > $out || exit 1

scripts/nix-pull.in

@@ -38,7 +38,7 @@ while (<CONFFILE>) {
             # Nix archive from the network.
             my $fetch =
               "App(IncludeFix(\"fetchurl/fetchurl.fix\"), " .
-              "[(\"url\", \"$url/$fn\"), (\"hash\", \"\")])";
+              "[(\"url\", \"$url/$fn\"), (\"md5\", \"ignore\")])";
             my $fixexpr = 
                 "App(IncludeFix(\"nar/unnar.fix\"), " .
                 "[ (\"nar\", $fetch)" .

scripts/nix-push.in

@@ -2,14 +2,14 @@
 
 my @pushlist;
 
-foreach my $hash (@ARGV) {
+foreach my $id (@ARGV) {
 
-    die unless $hash =~ /^([0-9a-z]{32})$/;
+    die unless $id =~ /^([0-9a-z]{32})$/;
 
     # Get all paths referenced by the normalisation of the given 
     # fstate expression.
     my @paths;
-    open PATHS, "nix -qrh $hash 2> /dev/null |" or die "nix -qrh";
+    open PATHS, "nix -qrh $id 2> /dev/null |" or die "nix -qrh";
     while (<PATHS>) {
         chomp;
         next unless /^\//;
@@ -21,15 +21,12 @@ foreach my $hash (@ARGV) {
     # a Nix archive.
     foreach my $path (@paths) {
 
-        # Hash the path.
-        my $phash = `nix-hash $path`;
-        $? and die "nix-hash";
-        chomp $phash;
-        die unless $phash =~ /^([0-9a-z]{32})$/;
+	next unless ($path =~ /\/([0-9a-z]{32})[^\/]*/);
+	my $pathid = $1;
 
         # Construct a name for the Nix archive.  If the file is an
         # fstate successor, encode this into the name.
-        my $name = $phash;
+        my $name = $pathid;
         if ($path =~ /-s-([0-9a-z]{32}).nix$/) {
             $name = "$name-s-$1";
         }
@@ -38,7 +35,7 @@ foreach my $hash (@ARGV) {
         # Construct a Fix expression that creates a Nix archive.
         my $fixexpr = 
           "App(IncludeFix(\"nar/nar.fix\"), " .
-          "[ (\"path\", Path(\"$path\", Hash(\"$phash\"), [Include(\"$hash\")]))" .
+          "[ (\"path\", Slice([\"$pathid\"], [(\"$path\", \"$pathid\", [])]))" .
           ", (\"name\", \"$name\")" .
           "])";
 	
@@ -48,13 +45,13 @@ foreach my $hash (@ARGV) {
         close FIX;
 
         # Instantiate a Nix expression from the Fix expression.
-        my $nhash = `fix $fixfile`;
+        my $nid = `fix $fixfile`;
         $? and die "instantiating Nix archive expression";
-        chomp $nhash;
-        die unless $nhash =~ /^([0-9a-z]{32})$/;
+        chomp $nid;
+        die unless $nid =~ /^([0-9a-z]{32})$/;
 
         # Realise the Nix expression.
-        my $npath = `nix -qph $nhash 2> /dev/null`;
+        my $npath = `nix -qph $nid 2> /dev/null`;
         $? and die "creating Nix archive";
         chomp $npath;
 

src/db.cc

@@ -65,6 +65,9 @@ bool queryDB(const string & filename, const string & dbname,
         err = db->get(0, &kt, &dt, 0);
         if (err) return false;
 
+        if (!dt.get_data())
+            data = "";
+        else
             data = string((char *) dt.get_data(), dt.get_size());
     
     } catch (DbException e) { rethrow(e); }

src/fix.cc

@@ -111,6 +111,14 @@ static Expr evalExpr(Expr e)
         ATmatch(e, "FSId(<str>)", &s1))
         return e;
 
+    if (ATgetType(e) == AT_APPL && 
+        ((string) ATgetName(ATgetAFun(e)) == "Slice" ||
+         (string) ATgetName(ATgetAFun(e)) == "Derive"))
+    {
+        return ATmake("FSId(<str>)", 
+            ((string) writeTerm(e, "", 0)).c_str());
+    }
+
     /* Application. */
     if (ATmatch(e, "App(<term>, [<list>])", &e1, &e2)) {
         e1 = evalExpr(e1);

src/fstate.cc

@@ -21,15 +21,22 @@ typedef map<string, string> Environment;
 class AutoDelete
 {
     string path;
+    bool del;
 public:
 
     AutoDelete(const string & p) : path(p) 
     {
+        del = true;
     }
 
     ~AutoDelete()
     {
-        deletePath(path);
+        if (del) deletePath(path);
+    }
+
+    void cancel()
+    {
+        del = false;
     }
 };
 
@@ -114,9 +121,11 @@ static void runProgram(const string & program, Environment env)
     if (waitpid(pid, &status, 0) != pid)
         throw Error("unable to wait for child");
     
-    if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
+    if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+        delTmpDir.cancel();
         throw Error("unable to build package");
     }
+}
 
 
 /* Throw an exception if the given platform string is not supported by
@@ -336,7 +345,7 @@ static Slice normaliseFState2(FSId id, StringSet & usedPaths)
         bnds = ATgetNext(bnds);
     }
 
-    /* Check that none of the output paths exist. */
+    /* Parse the outputs. */
     typedef map<string, FSId> OutPaths;
     OutPaths outPaths;
     while (!ATisEmpty(outs)) {
@@ -349,6 +358,25 @@ static Slice normaliseFState2(FSId id, StringSet & usedPaths)
         outs = ATgetNext(outs);
     }
 
+    /* We can skip running the builder if we can expand all output
+       paths from their ids. */
+    bool fastBuild = false;
+#if 0
+    for (OutPaths::iterator i = outPaths.begin(); 
+         i != outPaths.end(); i++)
+    {
+        try {
+            expandId(i->second, i->first);
+        } catch (...) {
+            fastBuild = false;
+            break;
+        }
+    }
+#endif
+
+    if (!fastBuild) {
+
+        /* Check that none of the outputs exist. */
         for (OutPaths::iterator i = outPaths.begin(); 
              i != outPaths.end(); i++)
             if (pathExists(i->first))
@@ -357,6 +385,9 @@ static Slice normaliseFState2(FSId id, StringSet & usedPaths)
         /* Run the builder. */
         runProgram(builder, env);
         
+    } else
+        debug(format("skipping build"));
+
     Slice slice;
 
     /* Check whether the output paths were created, and register each

src/store.cc

@@ -86,6 +86,7 @@ void copyPath(string src, string dst)
 
 void registerSubstitute(const FSId & srcId, const FSId & subId)
 {
+#if 0
     Strings subs;
     queryListDB(nixDB, dbSubstitutes, srcId, subs); /* non-existence = ok */
 
@@ -94,6 +95,12 @@ void registerSubstitute(const FSId & srcId, const FSId & subId)
     
     subs.push_back(subId);
     
+    setListDB(nixDB, dbSubstitutes, srcId, subs);
+#endif
+
+    /* For now, accept only one substitute per id. */
+    Strings subs;
+    subs.push_back(subId);
     setListDB(nixDB, dbSubstitutes, srcId, subs);
 }
 
@@ -126,6 +133,8 @@ void unregisterPath(const string & _path)
         return;
     FSId id(parseHash(_id));
 
+    delDB(nixDB, dbPath2Id, path);
+
     /* begin transaction */
     
     Strings paths, paths2;
@@ -140,6 +149,7 @@ void unregisterPath(const string & _path)
         setListDB(nixDB, dbId2Paths, id, paths2);
 
     /* end transaction */
+
 }
 
 
@@ -189,32 +199,31 @@ string expandId(const FSId & id, const string & target,
         }
     }
 
-#if 0
     /* Try to realise the substitutes. */
 
     Strings subs;
     queryListDB(nixDB, dbSubstitutes, id, subs); /* non-existence = ok */
 
     for (Strings::iterator it = subs.begin(); it != subs.end(); it++) {
-        realiseSlice(normaliseFState(*it));
+        FSId subId = parseHash(*it);
+        Slice slice = normaliseFState(subId);
+        realiseSlice(slice);
         
-        FState nf = realiseFState(hash2fstate(parseHash(*it)), dummy);
-        string path = fstatePath(nf);
-
-        if (hashPath(path) != hash)
-            throw Error(format("bad substitute in `%1%'") % (string) path);
+        Strings paths = fstatePaths(subId, true);
+        if (paths.size() != 1) 
+            throw Error("substitute created more than 1 path");
+        string path = *(paths.begin());
 
         if (target.empty())
             return path; /* !!! prefix */
         else {
             if (path != target) {
                 copyPath(path, target);
-                registerPath(target, hash);
+                registerPath(target, id);
             }
             return target;
         }
     }
-#endif
     
     throw Error(format("cannot expand id `%1%'") % (string) id);
 }