[NETD-BPF#1] Move libnetdutils to frameworks/libs/net/...

libnetdutils is referenced by netd.c and TrafficController.cpp, which
are going to be mainlined. Therefore, move libnetdutils to a common
place where both mainline module and platform code (Netd) can refer to.

Bug: 202086915
Test: build; flash; cd system/netd; atest
Ignore-AOSP-First: the netd change(same topic) would not automerge from
aosp.
No-Typo-Check: Clean code move with no other changes.
BYPASS_INCLUSIVE_LANGUAGE_REASON=Clean code move with no other changes.
Change-Id: I645bfe35f6543149c9a9f894cd4158d27a481abe
diff --git a/staticlibs/netd/libnetdutils/Log.cpp b/staticlibs/netd/libnetdutils/Log.cpp
new file mode 100644
index 0000000..d2ce98f
--- /dev/null
+++ b/staticlibs/netd/libnetdutils/Log.cpp
@@ -0,0 +1,216 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * 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 "netdutils/Log.h"
+#include "netdutils/Slice.h"
+
+#include <chrono>
+#include <ctime>
+#include <iomanip>
+#include <mutex>
+#include <sstream>
+
+#include <android-base/strings.h>
+#include <log/log.h>
+
+using ::android::base::Join;
+using ::android::base::StringPrintf;
+
+namespace android {
+namespace netdutils {
+
+namespace {
+
+std::string makeTimestampedEntry(const std::string& entry) {
+    using ::std::chrono::duration_cast;
+    using ::std::chrono::milliseconds;
+    using ::std::chrono::system_clock;
+
+    std::stringstream tsEntry;
+    const auto now = system_clock::now();
+    const auto time_sec = system_clock::to_time_t(now);
+    tsEntry << std::put_time(std::localtime(&time_sec), "%m-%d %H:%M:%S.") << std::setw(3)
+            << std::setfill('0')
+            << duration_cast<milliseconds>(now - system_clock::from_time_t(time_sec)).count() << " "
+            << entry;
+
+    return tsEntry.str();
+}
+
+}  // namespace
+
+std::string LogEntry::toString() const {
+    std::vector<std::string> text;
+
+    if (!mMsg.empty()) text.push_back(mMsg);
+    if (!mFunc.empty()) {
+        text.push_back(StringPrintf("%s(%s)", mFunc.c_str(), Join(mArgs, ", ").c_str()));
+    }
+    if (!mReturns.empty()) {
+        text.push_back("->");
+        text.push_back(StringPrintf("(%s)", Join(mReturns, ", ").c_str()));
+    }
+    if (!mUid.empty()) text.push_back(mUid);
+    if (!mDuration.empty()) text.push_back(StringPrintf("(%s)", mDuration.c_str()));
+
+    return Join(text, " ");
+}
+
+LogEntry& LogEntry::message(const std::string& message) {
+    mMsg = message;
+    return *this;
+}
+
+LogEntry& LogEntry::function(const std::string& function_name) {
+    mFunc = function_name;
+    return *this;
+}
+
+LogEntry& LogEntry::prettyFunction(const std::string& pretty_function) {
+    // __PRETTY_FUNCTION__ generally seems to be of the form:
+    //
+    //     qualifed::returnType qualified::function(args...)
+    //
+    // where the qualified forms include "(anonymous namespace)" in the
+    // "::"-delimited list and keywords like "virtual" (where applicable).
+    //
+    // Here we try to convert strings like:
+    //
+    //     virtual binder::Status android::net::NetdNativeService::isAlive(bool *)
+    //     netdutils::LogEntry android::netd::(anonymous namespace)::AAA::BBB::function()
+    //
+    // into just "NetdNativeService::isAlive" or "BBB::function". Note that
+    // without imposing convention, how to easily identify any namespace/class
+    // name boundary is not obvious.
+    const size_t endFuncName = pretty_function.rfind('(');
+    const size_t precedingSpace = pretty_function.rfind(' ', endFuncName);
+    size_t substrStart = (precedingSpace != std::string::npos) ? precedingSpace + 1 : 0;
+
+    const size_t beginFuncName = pretty_function.rfind("::", endFuncName);
+    if (beginFuncName != std::string::npos && substrStart < beginFuncName) {
+        const size_t previousNameBoundary = pretty_function.rfind("::", beginFuncName - 1);
+        if (previousNameBoundary < beginFuncName && substrStart < previousNameBoundary) {
+            substrStart = previousNameBoundary + 2;
+        } else {
+            substrStart = beginFuncName + 2;
+        }
+    }
+
+    mFunc = pretty_function.substr(substrStart, endFuncName - substrStart);
+    return *this;
+}
+
+LogEntry& LogEntry::arg(const std::string& val) {
+    mArgs.push_back(val.empty() ? "\"\"" : val);
+    return *this;
+}
+
+template <>
+LogEntry& LogEntry::arg<>(bool val) {
+    mArgs.push_back(val ? "true" : "false");
+    return *this;
+}
+
+LogEntry& LogEntry::arg(const std::vector<int32_t>& val) {
+    mArgs.push_back(StringPrintf("[%s]", Join(val, ", ").c_str()));
+    return *this;
+}
+
+LogEntry& LogEntry::arg(const std::vector<uint8_t>& val) {
+    mArgs.push_back('{' + toHex(makeSlice(val)) + '}');
+    return *this;
+}
+
+LogEntry& LogEntry::arg(const std::vector<std::string>& val) {
+    mArgs.push_back(StringPrintf("[%s]", Join(val, ", ").c_str()));
+    return *this;
+}
+
+LogEntry& LogEntry::returns(const std::string& rval) {
+    mReturns.push_back(rval);
+    return *this;
+}
+
+LogEntry& LogEntry::returns(bool rval) {
+    mReturns.push_back(rval ? "true" : "false");
+    return *this;
+}
+
+LogEntry& LogEntry::returns(const Status& status) {
+    mReturns.push_back(status.msg());
+    return *this;
+}
+
+LogEntry& LogEntry::withUid(uid_t uid) {
+    mUid = StringPrintf("(uid=%d)", uid);
+    return *this;
+}
+
+LogEntry& LogEntry::withAutomaticDuration() {
+    using ms = std::chrono::duration<float, std::ratio<1, 1000>>;
+
+    const std::chrono::steady_clock::time_point end = std::chrono::steady_clock::now();
+    std::stringstream duration;
+    duration << std::setprecision(1) << std::chrono::duration_cast<ms>(end - mStart).count()
+             << "ms";
+    mDuration = duration.str();
+    return *this;
+}
+
+LogEntry& LogEntry::withDuration(const std::string& duration) {
+    mDuration = duration;
+    return *this;
+}
+
+Log::~Log() {
+    // TODO: dump the last N entries to the android log for possible posterity.
+    info(LogEntry().function(__FUNCTION__));
+}
+
+void Log::forEachEntry(const std::function<void(const std::string&)>& perEntryFn) const {
+    // We make a (potentially expensive) copy of the log buffer (including
+    // all strings), in case the |perEntryFn| takes its sweet time.
+    std::deque<std::string> entries;
+    {
+        std::shared_lock<std::shared_mutex> guard(mLock);
+        entries.assign(mEntries.cbegin(), mEntries.cend());
+    }
+
+    for (const std::string& entry : entries) perEntryFn(entry);
+}
+
+void Log::record(Log::Level lvl, const std::string& entry) {
+    switch (lvl) {
+        case Level::LOG:
+            break;
+        case Level::INFO:
+            ALOG(LOG_INFO, mTag.c_str(), "%s", entry.c_str());
+            break;
+        case Level::WARN:
+            ALOG(LOG_WARN, mTag.c_str(), "%s", entry.c_str());
+            break;
+        case Level::ERROR:
+            ALOG(LOG_ERROR, mTag.c_str(), "%s", entry.c_str());
+            break;
+    }
+
+    std::lock_guard guard(mLock);
+    mEntries.push_back(makeTimestampedEntry(entry));
+    while (mEntries.size() > mMaxEntries) mEntries.pop_front();
+}
+
+}  // namespace netdutils
+}  // namespace android