[gentoo-commits] proj/libbash:master commit in: src/builtins/

[Petteri Räty]

commit:     4e2bf0c6eb6f291a5d151d82c486c7fb73d7f33f
Author:     Mu Qiao <qiaomuf <AT> gentoo <DOT> org>
AuthorDate: Thu May  5 07:18:27 2011 +0000
Commit:     Petteri Räty <betelgeuse <AT> gentoo <DOT> org>
CommitDate: Sun May  8 12:55:52 2011 +0000
URL:        http://git.overlays.gentoo.org/gitweb/?p=proj/libbash.git;a=commit;h=4e2bf0c6

Builtin: cache AST inside source builtin

AST can be reused in order to improve the performance. Now we use
a static variable inside the source builtin to cache all the ASTs
created by the builtin. In future we may define rules to change the
internal behavior.

---
 src/builtins/source_builtin.cpp |   18 +++++++++++++-----
 1 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/builtins/source_builtin.cpp b/src/builtins/source_builtin.cpp
index d2b4bcb..6ba6b11 100644
--- a/src/builtins/source_builtin.cpp
+++ b/src/builtins/source_builtin.cpp
@@ -26,6 +26,7 @@
 
 #include <fstream>
 #include <string>
+#include <unordered_map>
 
 #include "cppbash_builtin.h"
 #include "core/interpreter.h"
@@ -34,17 +35,24 @@
 
 int source_builtin::exec(const std::vector<std::string>& bash_args)
 {
+  static std::unordered_map<std::string, std::shared_ptr<bash_ast>> ast_cache;
+
   if(bash_args.size() == 0)
     throw interpreter_exception("should provide one argument for source builtin");
 
   // we need fix this to pass extra arguments as positional parameters
   const std::string& path = bash_args[0];
-  std::ifstream input(path);
-  if(!input)
-    throw interpreter_exception(path + " can't be read");
 
-  bash_ast ast(input);
-  ast.interpret_with(_walker);
+  auto& stored_ast = ast_cache[path];
+  if(!stored_ast)
+  {
+    std::ifstream input(path);
+    if(!input)
+      throw interpreter_exception(path + " can't be read");
+
+    stored_ast.reset(new bash_ast(input));
+  }
+  stored_ast->interpret_with(_walker);
 
   return _walker.get_status();
 }