Adding support for Reset in StringTokenizerT and HttpHeadersIterator.

TEST=Run HeadersIterator_Reset and the Reset test for StringTokenizer
BUG=none

Review URL: http://codereview.chromium.org/276067

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@29330 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 29 insertions, 0 deletions

diff --git a/base/string_tokenizer.h b/base/string_tokenizer.h
index eb9ac2d..a6b5870 100644
--- a/base/string_tokenizer.h
+++ b/base/string_tokenizer.h
@@ -141,6 +141,11 @@ class StringTokenizerT {
     return true;
   }
 
+  // Start iterating through tokens from the beginning of the string.
+  void Reset() {
+    token_end_ = start_pos_;
+  }
+
   // Returns true if token is a delimiter.  When the tokenizer is constructed
   // with the RETURN_DELIMS option, this method can be used to check if the
   // returned token is actually a delimiter.
@@ -156,6 +161,7 @@ class StringTokenizerT {
   void Init(const_iterator string_begin,
             const_iterator string_end,
             const str& delims) {
+    start_pos_ = string_begin;
     token_end_ = string_begin;
     end_ = string_end;
     delims_ = delims;
@@ -195,6 +201,7 @@ class StringTokenizerT {
     return true;
   }
 
+  const_iterator start_pos_;
   const_iterator token_begin_;
   const_iterator token_end_;
   const_iterator end_;
diff --git a/base/string_tokenizer_unittest.cc b/base/string_tokenizer_unittest.cc
index a9e98cd..80cb960 100644
--- a/base/string_tokenizer_unittest.cc
+++ b/base/string_tokenizer_unittest.cc
@@ -30,6 +30,28 @@ TEST(StringTokenizerTest, Simple) {
   EXPECT_FALSE(t.GetNext());
 }
 
+TEST(StringTokenizerTest, Reset) {
+  string input = "this is a test";
+  StringTokenizer t(input, " ");
+
+  for (int i = 0; i < 2; ++i) {
+    EXPECT_TRUE(t.GetNext());
+    EXPECT_EQ(string("this"), t.token());
+
+    EXPECT_TRUE(t.GetNext());
+    EXPECT_EQ(string("is"), t.token());
+
+    EXPECT_TRUE(t.GetNext());
+    EXPECT_EQ(string("a"), t.token());
+
+    EXPECT_TRUE(t.GetNext());
+    EXPECT_EQ(string("test"), t.token());
+
+    EXPECT_FALSE(t.GetNext());
+    t.Reset();
+  }
+}
+
 TEST(StringTokenizerTest, RetDelims) {
   string input = "this is a test";
   StringTokenizer t(input, " ");