diff options
author | Vincent Ambo <tazjin@google.com> | 2020-05-20T01·32+0100 |
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committer | Vincent Ambo <tazjin@google.com> | 2020-05-20T01·32+0100 |
commit | fc8dc48020ac5b52731d0828a96ea4d2526c77ba (patch) | |
tree | 353204eea3268095a9ad3f5345720f32c2615c69 /third_party/abseil_cpp/absl/time/internal/cctz/src/time_zone_lookup.cc | |
parent | ffb2ae54beb5796cd408fbe15d2d2da09ff37adf (diff) | |
parent | 768eb2ca2857342673fcd462792ce04b8bac3fa3 (diff) |
Add 'third_party/abseil_cpp/' from commit '768eb2ca2857342673fcd462792ce04b8bac3fa3' r/781
git-subtree-dir: third_party/abseil_cpp git-subtree-mainline: ffb2ae54beb5796cd408fbe15d2d2da09ff37adf git-subtree-split: 768eb2ca2857342673fcd462792ce04b8bac3fa3
Diffstat (limited to 'third_party/abseil_cpp/absl/time/internal/cctz/src/time_zone_lookup.cc')
-rw-r--r-- | third_party/abseil_cpp/absl/time/internal/cctz/src/time_zone_lookup.cc | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/third_party/abseil_cpp/absl/time/internal/cctz/src/time_zone_lookup.cc b/third_party/abseil_cpp/absl/time/internal/cctz/src/time_zone_lookup.cc new file mode 100644 index 000000000000..efdea64b4eb1 --- /dev/null +++ b/third_party/abseil_cpp/absl/time/internal/cctz/src/time_zone_lookup.cc @@ -0,0 +1,187 @@ +// Copyright 2016 Google Inc. 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 +// +// https://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 "absl/base/config.h" +#include "absl/time/internal/cctz/include/cctz/time_zone.h" + +#if defined(__ANDROID__) +#include <sys/system_properties.h> +#if defined(__ANDROID_API__) && __ANDROID_API__ >= 21 +#include <dlfcn.h> +#endif +#endif + +#if defined(__APPLE__) +#include <CoreFoundation/CFTimeZone.h> + +#include <vector> +#endif + +#include <cstdlib> +#include <cstring> +#include <string> + +#include "time_zone_fixed.h" +#include "time_zone_impl.h" + +namespace absl { +ABSL_NAMESPACE_BEGIN +namespace time_internal { +namespace cctz { + +#if defined(__ANDROID__) && defined(__ANDROID_API__) && __ANDROID_API__ >= 21 +namespace { +// Android 'L' removes __system_property_get() from the NDK, however +// it is still a hidden symbol in libc so we use dlsym() to access it. +// See Chromium's base/sys_info_android.cc for a similar example. + +using property_get_func = int (*)(const char*, char*); + +property_get_func LoadSystemPropertyGet() { + int flag = RTLD_LAZY | RTLD_GLOBAL; +#if defined(RTLD_NOLOAD) + flag |= RTLD_NOLOAD; // libc.so should already be resident +#endif + if (void* handle = dlopen("libc.so", flag)) { + void* sym = dlsym(handle, "__system_property_get"); + dlclose(handle); + return reinterpret_cast<property_get_func>(sym); + } + return nullptr; +} + +int __system_property_get(const char* name, char* value) { + static property_get_func system_property_get = LoadSystemPropertyGet(); + return system_property_get ? system_property_get(name, value) : -1; +} + +} // namespace +#endif + +std::string time_zone::name() const { return effective_impl().Name(); } + +time_zone::absolute_lookup time_zone::lookup( + const time_point<seconds>& tp) const { + return effective_impl().BreakTime(tp); +} + +time_zone::civil_lookup time_zone::lookup(const civil_second& cs) const { + return effective_impl().MakeTime(cs); +} + +bool time_zone::next_transition(const time_point<seconds>& tp, + civil_transition* trans) const { + return effective_impl().NextTransition(tp, trans); +} + +bool time_zone::prev_transition(const time_point<seconds>& tp, + civil_transition* trans) const { + return effective_impl().PrevTransition(tp, trans); +} + +std::string time_zone::version() const { return effective_impl().Version(); } + +std::string time_zone::description() const { + return effective_impl().Description(); +} + +const time_zone::Impl& time_zone::effective_impl() const { + if (impl_ == nullptr) { + // Dereferencing an implicit-UTC time_zone is expected to be + // rare, so we don't mind paying a small synchronization cost. + return *time_zone::Impl::UTC().impl_; + } + return *impl_; +} + +bool load_time_zone(const std::string& name, time_zone* tz) { + return time_zone::Impl::LoadTimeZone(name, tz); +} + +time_zone utc_time_zone() { + return time_zone::Impl::UTC(); // avoid name lookup +} + +time_zone fixed_time_zone(const seconds& offset) { + time_zone tz; + load_time_zone(FixedOffsetToName(offset), &tz); + return tz; +} + +time_zone local_time_zone() { + const char* zone = ":localtime"; +#if defined(__ANDROID__) + char sysprop[PROP_VALUE_MAX]; + if (__system_property_get("persist.sys.timezone", sysprop) > 0) { + zone = sysprop; + } +#endif +#if defined(__APPLE__) + std::vector<char> buffer; + CFTimeZoneRef tz_default = CFTimeZoneCopyDefault(); + if (CFStringRef tz_name = CFTimeZoneGetName(tz_default)) { + CFStringEncoding encoding = kCFStringEncodingUTF8; + CFIndex length = CFStringGetLength(tz_name); + buffer.resize(CFStringGetMaximumSizeForEncoding(length, encoding) + 1); + if (CFStringGetCString(tz_name, &buffer[0], buffer.size(), encoding)) { + zone = &buffer[0]; + } + } + CFRelease(tz_default); +#endif + + // Allow ${TZ} to override to default zone. + char* tz_env = nullptr; +#if defined(_MSC_VER) + _dupenv_s(&tz_env, nullptr, "TZ"); +#else + tz_env = std::getenv("TZ"); +#endif + if (tz_env) zone = tz_env; + + // We only support the "[:]<zone-name>" form. + if (*zone == ':') ++zone; + + // Map "localtime" to a system-specific name, but + // allow ${LOCALTIME} to override the default name. + char* localtime_env = nullptr; + if (strcmp(zone, "localtime") == 0) { +#if defined(_MSC_VER) + // System-specific default is just "localtime". + _dupenv_s(&localtime_env, nullptr, "LOCALTIME"); +#else + zone = "/etc/localtime"; // System-specific default. + localtime_env = std::getenv("LOCALTIME"); +#endif + if (localtime_env) zone = localtime_env; + } + + const std::string name = zone; +#if defined(_MSC_VER) + free(localtime_env); + free(tz_env); +#endif + + time_zone tz; + load_time_zone(name, &tz); // Falls back to UTC. + // TODO: Follow the RFC3339 "Unknown Local Offset Convention" and + // arrange for %z to generate "-0000" when we don't know the local + // offset because the load_time_zone() failed and we're using UTC. + return tz; +} + +} // namespace cctz +} // namespace time_internal +ABSL_NAMESPACE_END +} // namespace absl |