* Negative caching, i.e. caching of build failures. Disabled by

  default.  This is mostly useful for Hydra.

1 files changed, 22 insertions, 0 deletions

diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index fdfc8534662a..7ab7e4e8e375 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -65,6 +65,7 @@ LocalStore::LocalStore()
 
     createDirs(nixDBPath + "/info");
     createDirs(nixDBPath + "/referrer");
+    createDirs(nixDBPath + "/failed");
 
     int curSchema = getSchema();
     if (curSchema > nixSchemaVersion)
@@ -196,6 +197,13 @@ static Path referrersFileFor(const Path & path)
 }
 
 
+static Path failedFileFor(const Path & path)
+{
+    string baseName = baseNameOf(path);
+    return (format("%1%/failed/%2%") % nixDBPath % baseName).str();
+}
+
+
 static Path tmpFileForAtomicUpdate(const Path & path)
 {
     return (format("%1%/.%2%.%3%") % dirOf(path) % getpid() % baseNameOf(path)).str();
@@ -335,6 +343,20 @@ void LocalStore::registerValidPath(const ValidPathInfo & info, bool ignoreValidi
 }
 
 
+void LocalStore::registerFailedPath(const Path & path)
+{
+    /* Write an empty file in the .../failed directory to denote the
+       failure of the builder for `path'. */
+    writeFile(failedFileFor(path), "");
+}
+
+
+bool LocalStore::hasPathFailed(const Path & path)
+{
+    return pathExists(failedFileFor(path));
+}
+
+
 Hash parseHashField(const Path & path, const string & s)
 {
     string::size_type colon = s.find(':');