string_util: Remove StartsWithASCII

This was used in exactly one location, FingerState::FlagsString, and can
easily be replaced by a call to std::string::rfind. Also add a new test
case to verify the change.

BUG=b:245989146
TEST=cros_sdk env FEATURES="test" emerge-${BOARD} chromeos-base/gestures

Change-Id: I832dd9a7cb61b3a4741d2a3439b4884746274f3b
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/gestures/+/5318731
Commit-Queue: Harry Cutts <hcutts@chromium.org>
Tested-by: Harry Cutts <hcutts@chromium.org>
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>
Code-Coverage: Zoss <zoss-cl-coverage@prod.google.com>
Reviewed-by: Henry Barnor <hbarnor@chromium.org>

5 files changed, 15 insertions, 20 deletions

diff --git a/include/string_util.h b/include/string_util.h
index c604330..decaef9 100644
--- a/include/string_util.h
+++ b/include/string_util.h
@@ -38,11 +38,6 @@ TrimPositions TrimWhitespaceASCII(const std::string& input,
                                               TrimPositions positions,
                                               std::string* output);
 
-// Returns true if str starts with search, or false otherwise.
-bool StartsWithASCII(const std::string& str,
-                     const std::string& search,
-                     bool case_sensitive);
-
 }  // namespace gestures
 
 #endif  // GESTURES_STRING_UTIL_H_
diff --git a/src/gestures.cc b/src/gestures.cc
index b4d5271..a8594cc 100644
--- a/src/gestures.cc
+++ b/src/gestures.cc
@@ -42,7 +42,6 @@
 using std::string;
 using std::min;
 using gestures::StringPrintf;
-using gestures::StartsWithASCII;
 
 // C API:
 
@@ -135,9 +134,9 @@ string FingerState::FlagsString(unsigned flags) {
   if (flags) {
     // prepend remaining number
     ret = StringPrintf("%u%s", flags, ret.c_str());
-  } else if (StartsWithASCII(ret, kPipeSeparator, false)) {
+  } else if (ret.rfind(kPipeSeparator, 0) == 0) {
     // strip extra pipe
-    ret = string(ret.c_str() + strlen(kPipeSeparator));
+    ret = ret.substr(strlen(kPipeSeparator));
   } else {
     ret = "0";
   }
diff --git a/src/gestures_unittest.cc b/src/gestures_unittest.cc
index 6b00902..b11a339 100644
--- a/src/gestures_unittest.cc
+++ b/src/gestures_unittest.cc
@@ -411,6 +411,19 @@ TEST(GesturesTest, StimeFromTimespecTest) {
   EXPECT_DOUBLE_EQ(2000000000.999999999, StimeFromTimespec(&tv));
 }
 
+TEST(GesturesTest, FingerStateFlagsStringTest) {
+  EXPECT_EQ("0", FingerState::FlagsString(0));
+  EXPECT_EQ("GESTURES_FINGER_PALM",
+            FingerState::FlagsString(GESTURES_FINGER_PALM));
+  EXPECT_EQ("GESTURES_FINGER_PALM | GESTURES_FINGER_WARP_X_MOVE",
+            FingerState::FlagsString(
+                GESTURES_FINGER_PALM | GESTURES_FINGER_WARP_X_MOVE));
+  // 1 << 31 probably won't be used as a finger flag value anytime soon, so use
+  // it to test prepending the remaining number.
+  EXPECT_EQ("2147483648 | GESTURES_FINGER_PALM",
+            FingerState::FlagsString(GESTURES_FINGER_PALM | (1 << 31)));
+}
+
 TEST(GesturesTest, HardwareStateGetFingerStateTest) {
   FingerState fs[] = {
     { 0, 0, 0, 0, 1, 0, 150, 4000, 4, 0 },
diff --git a/src/string_util.cc b/src/string_util.cc
index 3d5636c..be4fe21 100644
--- a/src/string_util.cc
+++ b/src/string_util.cc
@@ -132,15 +132,6 @@ std::string StringPrintf(const char* format, ...) {
   return result;
 }
 
-bool StartsWithASCII(const std::string& str,
-                     const std::string& search,
-                     bool case_sensitive) {
-  if (case_sensitive)
-    return str.compare(0, search.length(), search) == 0;
-  else
-    return strncasecmp(str.c_str(), search.c_str(), search.length()) == 0;
-}
-
 TrimPositions TrimWhitespaceASCII(const std::string& input,
                                   TrimPositions positions,
                                   std::string* output) {
diff --git a/src/string_util_unittest.cc b/src/string_util_unittest.cc
index 3135d58..3529ab9 100644
--- a/src/string_util_unittest.cc
+++ b/src/string_util_unittest.cc
@@ -30,9 +30,6 @@ TEST(StringUtilTest, SimpleTest) {
   TrimPositions trimmed_from = TrimWhitespaceASCII(str, TRIM_ALL, &str);
   EXPECT_EQ(trimmed_from, TRIM_ALL);
   EXPECT_EQ(str.size(), expected_length-2);
-
-  bool matches = StartsWithASCII(str, pstr, true);
-  EXPECT_TRUE(matches);
 }
 
 }  // namespace gestures