commit c4bd0ac9a60f01e9e22884410fcf269d3b41b5ad
author Olli Etuaho <oetuaho@nvidia.com> Thu Feb 22 16:29:32 2018 +0200
committer Commit Bot <commit-bot@chromium.org> Mon Feb 26 15:05:44 2018 +0000
tree 7fc35308b45df0cfb943b7544b29e78cab17bfed
parent 2f7c04a3c5d7b392028ae4673dabd1085673f8e4

Add 32-bit hash helper to ImmutableString

Since the length of the hash is known prior to compilation, it can be
compared with script-generated hashes.

BUG=angleproject:2267
TEST=angle_unittests

Change-Id: Ia0a78dfd450c4ea2d526da7f3495b9750dcbd1af
Reviewed-on: https://chromium-review.googlesource.com/931884
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>

src/compiler/translator/ImmutableString.cpp

diff --git a/src/compiler/translator/ImmutableString.cpp b/src/compiler/translator/ImmutableString.cpp
index 6bb26af..8f26dc8 100644
--- a/src/compiler/translator/ImmutableString.cpp
+++ b/src/compiler/translator/ImmutableString.cpp
@@ -35,4 +35,17 @@
 const size_t ImmutableString::FowlerNollVoHash<8>::kFnvOffsetBasis =
     static_cast<size_t>(0xcbf29ce484222325ull);
 
+uint32_t ImmutableString::hash32() const
+{
+    const char *data_ptr = data();
+    uint32_t hash        = static_cast<uint32_t>(FowlerNollVoHash<4>::kFnvOffsetBasis);
+    while ((*data_ptr) != '\0')
+    {
+        hash = hash ^ (*data_ptr);
+        hash = hash * static_cast<uint32_t>(FowlerNollVoHash<4>::kFnvPrime);
+        ++data_ptr;
+    }
+    return hash;
+}
+
 }  // namespace sh

src/compiler/translator/ImmutableString.h

diff --git a/src/compiler/translator/ImmutableString.h b/src/compiler/translator/ImmutableString.h
index e077377..301e91c 100644
--- a/src/compiler/translator/ImmutableString.h
+++ b/src/compiler/translator/ImmutableString.h
@@ -128,6 +128,8 @@
         }
     };
 
+    uint32_t hash32() const;
+
   private:
     const char *mData;
     size_t mLength;