Exporting DJB hash to Lua.

Author: nicolasnoble

src/lua/extra.cc

@@ -28,6 +28,7 @@
 #include "lua/luawrapper.h"
 #include "support/file.h"
 #include "support/strings-helpers.h"
+#include "support/djbhash.h"
 #include "support/zip.h"
 
 namespace {
@@ -81,6 +82,30 @@ PCSX::File* load(std::string_view name, std::string_view from, bool inArchives =
     return new PCSX::PosixFile(absolutePath);
 }
 
+uint64_t djbHash(const char* str, size_t len) {
+    return PCSX::djb::hash(str, len);
+}
+
+template <typename T, size_t S>
+void registerSymbol(PCSX::Lua L, const char (&name)[S], const T ptr) {
+    L.push<S>(name);
+    L.push((void*)ptr);
+    L.settable();
+}
+
+#define REGISTER(L, s) registerSymbol(L, #s, s)
+
+void registerAllSymbols(PCSX::Lua L) {
+    L.getfieldtable("_CLIBS", LUA_REGISTRYINDEX);
+    L.push("SUPPORT_EXTRA");
+    L.newtable();
+
+    REGISTER(L, djbHash);
+
+    L.settable();
+    L.pop();
+}
+
 }  // namespace
 
 PCSX::ZipArchive& PCSX::LuaFFI::addArchive(Lua L, IO<File> file) {
@@ -138,6 +163,7 @@ void PCSX::LuaFFI::open_extra(Lua L) {
     static const char* extra = (
 #include "lua/extra.lua"
     );
+    registerAllSymbols(L);
     L.load(pprint, "third_party:pprint.lua/pprint.lua");
     L.load(pprint_internals, "third_party:pprint.lua/pprint-internals.lua");
     L.load(reflectFFI, "third_party:ffi-reflect/reflect.lua");

src/lua/extra.lua

@@ -15,6 +15,13 @@
 --   along with this program; if not, write to the
 --   Free Software Foundation, Inc.,
 --   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+ffi.cdef [[
+uint64_t djbHash(const char* str, size_t len);
+]]
+
+local C = ffi.load 'SUPPORT_EXTRA'
+
 Support.extra = {
 
     loadfile = function(name) return loadstring(Support._internal.loadfile(name), '@' .. name) end,
@@ -33,5 +40,8 @@ Support.extra = {
         error('FFI call failed in ' .. name .. ': ' .. ret)
     end,
 
+    djbHash = function(str)
+        return C.djbHash(str, #str)
+    end,
 }
 -- )EOF"