Cherry pick PR #1664: Correct Linux implementation of SbTimezoneGetNa…

…me (#1886)

Refer to the original PR: youtube/cobalt#1664

b/302569322

Change-Id: Icce69ed2db148020c44ab9d95af8d83283e3c138

Co-authored-by: johnxwork <[email protected]>
Co-authored-by: y4vor <[email protected]>

starboard/linux/shared/BUILD.gn

@@ -135,6 +135,7 @@ static_library("starboard_platform_sources") {
     "//starboard/shared/linux/thread_get_id.cc",
     "//starboard/shared/linux/thread_get_name.cc",
     "//starboard/shared/linux/thread_set_name.cc",
+    "//starboard/shared/linux/time_zone_get_name.cc",
     "//starboard/shared/nouser/user_get_current.cc",
     "//starboard/shared/nouser/user_get_property.cc",
     "//starboard/shared/nouser/user_get_signed_in.cc",
@@ -219,7 +220,6 @@ static_library("starboard_platform_sources") {
     "//starboard/shared/posix/time_get_now.cc",
     "//starboard/shared/posix/time_is_time_thread_now_supported.cc",
     "//starboard/shared/posix/time_zone_get_current.cc",
-    "//starboard/shared/posix/time_zone_get_name.cc",
     "//starboard/shared/pthread/condition_variable_broadcast.cc",
     "//starboard/shared/pthread/condition_variable_create.cc",
     "//starboard/shared/pthread/condition_variable_destroy.cc",

starboard/nplb/time_zone_get_name_test.cc

@@ -12,10 +12,19 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#include <string.h>
+
+#include "starboard/common/log.h"
+#include "starboard/extension/time_zone.h"
 #include "starboard/nplb/time_constants.h"
+#include "starboard/system.h"
 #include "starboard/time_zone.h"
+#include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+using testing::AnyOf;
+using testing::MatchesRegex;
+
 namespace starboard {
 namespace nplb {
 namespace {
@@ -41,6 +50,27 @@ TEST(SbTimeZoneGetNameTest, IsKindOfSane) {
   // ":Pacific/Kiritimati" is the western-most timezone at UTC+14.
 }
 
+TEST(SbTimeZoneGetNameTest, IsIANAFormat) {
+  const char* name = SbTimeZoneGetName();
+  SB_LOG(INFO) << "time zone name: " << name;
+  char cpy[100];
+  snprintf(cpy, sizeof(cpy), "%s", name);
+  char* continent = strtok(cpy, "/");
+  // The time zone ID starts with a Continent or Ocean name.
+  EXPECT_THAT(
+      continent,
+      testing::AnyOf(std::string("Asia"), std::string("America"),
+                     std::string("Africa"), std::string("Europe"),
+                     std::string("Australia"), std::string("Pacific"),
+                     std::string("Atlantic"), std::string("Antarctica"),
+                     // time zone can be "Etc/UTC" if unset(such as on
+                     // CI builders), shouldn't happen in production.
+                     // TODO(b/304351956): Remove Etc after fixing builders.
+                     std::string("Indian"), std::string("Etc")));
+  char* city = strtok(NULL, "/");
+  EXPECT_TRUE(strlen(city) != 0);
+}
+
 }  // namespace
 }  // namespace nplb
 }  // namespace starboard

starboard/raspi/shared/BUILD.gn

@@ -113,6 +113,7 @@ static_library("starboard_platform_sources") {
     "//starboard/shared/linux/thread_get_id.cc",
     "//starboard/shared/linux/thread_get_name.cc",
     "//starboard/shared/linux/thread_set_name.cc",
+    "//starboard/shared/linux/time_zone_get_name.cc",
     "//starboard/shared/nouser/user_get_current.cc",
     "//starboard/shared/nouser/user_get_property.cc",
     "//starboard/shared/nouser/user_get_signed_in.cc",
@@ -189,7 +190,6 @@ static_library("starboard_platform_sources") {
     "//starboard/shared/posix/time_get_now.cc",
     "//starboard/shared/posix/time_is_time_thread_now_supported.cc",
     "//starboard/shared/posix/time_zone_get_current.cc",
-    "//starboard/shared/posix/time_zone_get_name.cc",
     "//starboard/shared/pthread/condition_variable_broadcast.cc",
     "//starboard/shared/pthread/condition_variable_create.cc",
     "//starboard/shared/pthread/condition_variable_destroy.cc",

starboard/shared/linux/time_zone_get_name.cc

@@ -0,0 +1,75 @@
+// Copyright 2015 The Cobalt Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "starboard/common/log.h"
+#include "starboard/time_zone.h"
+
+#define TZDEFAULT "/etc/localtime"
+#define TZZONEINFOTAIL "/zoneinfo/"
+#define isNonDigit(ch) (ch < '0' || '9' < ch)
+
+static char gTimeZoneBuffer[PATH_MAX];
+static char* gTimeZoneBufferPtr = NULL;
+
+static bool isValidOlsonID(const char* id) {
+  int32_t idx = 0;
+
+  /* Determine if this is something like Iceland (Olson ID)
+  or AST4ADT (non-Olson ID) */
+  while (id[idx] && isNonDigit(id[idx]) && id[idx] != ',') {
+    idx++;
+  }
+
+  /* If we went through the whole string, then it might be okay.
+  The timezone is sometimes set to "CST-7CDT", "CST6CDT5,J129,J131/19:30",
+  "GRNLNDST3GRNLNDDT" or similar, so we cannot use it.
+  The rest of the time it could be an Olson ID. George */
+  return static_cast<bool>(id[idx] == 0 || strcmp(id, "PST8PDT") == 0 ||
+                           strcmp(id, "MST7MDT") == 0 ||
+                           strcmp(id, "CST6CDT") == 0 ||
+                           strcmp(id, "EST5EDT") == 0);
+}
+
+// Similar to how ICU::putil.cpp gets IANA(Olsen) timezone ID.
+const char* SbTimeZoneGetName() {
+  /*
+  This is a trick to look at the name of the link to get the Olson ID
+  because the tzfile contents is underspecified.
+  This isn't guaranteed to work because it may not be a symlink.
+  But this is production-tested solution for most versions of Linux.
+  */
+
+  if (gTimeZoneBufferPtr == NULL) {
+    int32_t ret = (int32_t)readlink(TZDEFAULT, gTimeZoneBuffer,
+                                    sizeof(gTimeZoneBuffer) - 1);
+    if (0 < ret) {
+      int32_t tzZoneInfoTailLen = strlen(TZZONEINFOTAIL);
+      gTimeZoneBuffer[ret] = 0;
+      char* tzZoneInfoTailPtr = strstr(gTimeZoneBuffer, TZZONEINFOTAIL);
+
+      if (tzZoneInfoTailPtr != NULL &&
+          isValidOlsonID(tzZoneInfoTailPtr + tzZoneInfoTailLen)) {
+        return (gTimeZoneBufferPtr = tzZoneInfoTailPtr + tzZoneInfoTailLen);
+      }
+    }
+    SB_NOTREACHED();
+    return "";
+  } else {
+    return gTimeZoneBufferPtr;
+  }
+}

starboard/time_zone.h

@@ -29,7 +29,7 @@ extern "C" {
 // The number of minutes west of the Greenwich Prime Meridian, NOT including
 // Daylight Savings Time adjustments.
 //
-// For example: PST/PDT is 480 minutes (28800 seconds, 8 hours).
+// For example: America/Los_Angeles is 480 minutes (28800 seconds, 8 hours).
 typedef int SbTimeZone;
 
 // Gets the system's current SbTimeZone in minutes.

starboard/win/win32/test_filters.py

@@ -53,6 +53,10 @@
 
         # Enable once verified on the platform.
         'SbMediaCanPlayMimeAndKeySystem.MinimumSupport',
+
+        # Windows uses a special time zone format that ICU accepts, so we don't enforce IANA.
+        # TODO(b/304335954): Re-enable the test after fixing Windows implementation.
+        'SbTimeZoneGetNameTest.IsIANAFormat',
     ],
     'player_filter_tests': [
         # These tests fail on our VMs for win-win32 builds due to missing