4 files changed, 53 insertions, 1 deletions

diff --git a/hash.cxx b/hash.cxx
index 61caa356..b8d5a0e4 100644
--- a/hash.cxx
+++ b/hash.cxx
@@ -237,4 +237,22 @@ find_hash (systemtap_session& s, const string& script)
   find_script_hash(s, script, base);
 }
 
+
+void
+find_tracequery_hash (systemtap_session& s)
+{
+  hash h;
+  get_base_hash(s, h);
+
+  // The basic hash should be good enough for the tracepoint query module
+
+  // Get the directory path to store our cached module
+  string result, hashdir;
+  h.result(result);
+  if (!create_hashdir(s, result, hashdir))
+    return;
+
+  s.tracequery_path = hashdir + "/tracequery_" + result + ".ko";
+}
+
 /* vim: set sw=2 ts=8 cino=>4,n-2,{2,^-2,t0,(0,u0,w1,M1 : */
diff --git a/hash.h b/hash.h
index d386ad03..0fe95e27 100644
--- a/hash.h
+++ b/hash.h
@@ -35,5 +35,6 @@ public:
 };
 
 void find_hash (systemtap_session& s, const std::string& script);
+void find_tracequery_hash (systemtap_session& s);
 
 /* vim: set sw=2 ts=8 cino=>4,n-2,{2,^-2,t0,(0,u0,w1,M1 : */
diff --git a/session.h b/session.h
index 820b819e..cbbae6b2 100644
--- a/session.h
+++ b/session.h
@@ -117,6 +117,7 @@ struct systemtap_session
   std::string cache_path;
   std::string hash_path;
   std::string stapconf_path;
+  std::string tracequery_path;
 
   // dwarfless operation
   bool consult_symtab;
diff --git a/tapsets.cxx b/tapsets.cxx
index bc567491..e9ade595 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -18,6 +18,7 @@
 #include "buildrun.h"
 #include "dwarf_wrappers.h"
 #include "auto_free.h"
+#include "hash.h"
 
 #include <cstdlib>
 #include <algorithm>
@@ -9993,12 +9994,43 @@ tracepoint_builder::init_dw(systemtap_session& s)
   if (dw != NULL)
     return true;
 
+  if (s.use_cache)
+    {
+      // see if the cached module exists
+      find_tracequery_hash(s);
+      if (!s.tracequery_path.empty())
+        {
+          int fd = open(s.tracequery_path.c_str(), O_RDONLY);
+          if (fd != -1)
+            {
+              if (s.verbose > 2)
+                clog << "Pass 2: using cached " << s.tracequery_path << endl;
+
+              dw = new dwflpp(s);
+              dw->setup_user(s.tracequery_path);
+              close(fd);
+              return true;
+            }
+        }
+    }
+
+  // no cached module, time to make it
   string tracequery_ko;
   int rc = make_tracequery(s, tracequery_ko);
   if (rc != 0)
     return false;
 
-  // TODO cache tracequery.ko
+  if (s.use_cache)
+    {
+      // try to save tracequery in the cache
+      if (s.verbose > 2)
+        clog << "Copying " << tracequery_ko
+             << " to " << s.tracequery_path << endl;
+      if (copy_file(tracequery_ko.c_str(),
+                    s.tracequery_path.c_str()) != 0)
+        cerr << "Copy failed (\"" << tracequery_ko << "\" to \""
+             << s.tracequery_path << "\"): " << strerror(errno) << endl;
+    }
 
   dw = new dwflpp(s);
   dw->setup_user(tracequery_ko);