From caf705c863ee4bba3f7e634c846f6d8e6806bbb4 Mon Sep 17 00:00:00 2001
From: Victor Vazquez <victor.vazquez@microsoft.com>
Date: Fri, 4 Sep 2020 05:46:28 +0000
Subject: [PATCH] reuse code from tolower char (#583)

* reuse code from tolower char

* c_LocaleInvariant table to do tolower instead of toUpper
---
 sdk/core/azure-core/src/strings.cpp    | 39 ++++++++++----------------
 sdk/core/azure-core/test/ut/string.cpp | 12 ++++----
 2 files changed, 21 insertions(+), 30 deletions(-)

diff --git a/sdk/core/azure-core/src/strings.cpp b/sdk/core/azure-core/src/strings.cpp
index 55ec474ee..e6536ff5d 100644
--- a/sdk/core/azure-core/src/strings.cpp
+++ b/sdk/core/azure-core/src/strings.cpp
@@ -46,15 +46,15 @@ int main() {
 
 #endif
 
-const unsigned char c_LocaleInvariantUppercaseTable[256] = {
+const unsigned char c_LocaleInvariantLowercaseTable[256] = {
     0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
     0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F,
     0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F,
     0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F,
-    0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F,
-    0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F,
-    0x60, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F,
-    0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
+    0x40, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F,
+    0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F,
+    0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F,
+    0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
     0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F,
     0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F,
     0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF,
@@ -68,31 +68,22 @@ const unsigned char c_LocaleInvariantUppercaseTable[256] = {
 
 namespace Azure { namespace Core { namespace Details {
 
-  std::string const ToLower(const std::string& src) noexcept
+ 
+  inline unsigned char ToLower(const unsigned char symbol) noexcept
+  {
+    return c_LocaleInvariantLowercaseTable[symbol];
+  }
+
+   std::string const ToLower(const std::string& src) noexcept
   {
     auto result = std::string(src);
     for (auto i = result.begin(); i < result.end(); i++)
     {
-      *i = c_LocaleInvariantUppercaseTable[static_cast<unsigned char>(*i)];
-      if (*i >= 'A' && *i <= 'Z')
-      {
-        *i += 32;
-      }
+      *i = ToLower(static_cast<unsigned char>(*i));
     }
     return result;
   }
 
-  unsigned char ToLower(const unsigned char src) noexcept
-  {
-    auto result = c_LocaleInvariantUppercaseTable[src];
-    if (result >= 'A' && result <= 'Z')
-    {
-      result += 32;
-    }
-
-    return result;
-  }
-
   bool LocaleInvariantCaseInsensitiveEqual(const std::string& lhs, const std::string& rhs) noexcept
   {
     return std::equal(
@@ -101,8 +92,8 @@ namespace Azure { namespace Core { namespace Details {
         rhs.begin(),
         rhs.end(),
         [](const char left, const char right) noexcept {
-          return c_LocaleInvariantUppercaseTable[static_cast<unsigned char>(left)]
-              == c_LocaleInvariantUppercaseTable[static_cast<unsigned char>(right)];
+          return c_LocaleInvariantLowercaseTable[static_cast<unsigned char>(left)]
+              == c_LocaleInvariantLowercaseTable[static_cast<unsigned char>(right)];
         });
   }
 
diff --git a/sdk/core/azure-core/test/ut/string.cpp b/sdk/core/azure-core/test/ut/string.cpp
index 7476e8fca..e4babc2d7 100644
--- a/sdk/core/azure-core/test/ut/string.cpp
+++ b/sdk/core/azure-core/test/ut/string.cpp
@@ -10,14 +10,14 @@ TEST(String, invariantCompare)
   using Azure::Core::Details::LocaleInvariantCaseInsensitiveEqual;
   EXPECT_TRUE(LocaleInvariantCaseInsensitiveEqual("", ""));
   EXPECT_TRUE(LocaleInvariantCaseInsensitiveEqual("a", "a"));
-  EXPECT_TRUE(LocaleInvariantCaseInsensitiveEqual("a", "A"));
-  EXPECT_TRUE(LocaleInvariantCaseInsensitiveEqual("aa", "AA"));
-  EXPECT_TRUE(LocaleInvariantCaseInsensitiveEqual("aA", "AA"));
-  EXPECT_TRUE(LocaleInvariantCaseInsensitiveEqual("abc", "ABC"));
+  EXPECT_TRUE(LocaleInvariantCaseInsensitiveEqual("A", "a"));
+  EXPECT_TRUE(LocaleInvariantCaseInsensitiveEqual("AA", "aa"));
+  EXPECT_TRUE(LocaleInvariantCaseInsensitiveEqual("aA", "aa"));
+  EXPECT_TRUE(LocaleInvariantCaseInsensitiveEqual("ABC", "abc"));
   EXPECT_FALSE(LocaleInvariantCaseInsensitiveEqual("", "a"));
   EXPECT_FALSE(LocaleInvariantCaseInsensitiveEqual("a", ""));
-  EXPECT_FALSE(LocaleInvariantCaseInsensitiveEqual("a", "aA"));
-  EXPECT_FALSE(LocaleInvariantCaseInsensitiveEqual("abc", "abcd"));
+  EXPECT_FALSE(LocaleInvariantCaseInsensitiveEqual("A", "aA"));
+  EXPECT_FALSE(LocaleInvariantCaseInsensitiveEqual("ABC", "abcd"));
 }
 
 TEST(String, toLower)