logd/LogStatistics.h - android_system_core - Gitiles

 /*
  * Copyright (C) 2014 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.
  */

 #pragma once

 #include <ctype.h>
 #include <inttypes.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/types.h>

 #include <algorithm>  // std::max
 #include <array>
 #include <memory>
 #include <mutex>
 #include <string>
 #include <string_view>
 #include <unordered_map>

 #include <android-base/stringprintf.h>
 #include <android-base/thread_annotations.h>
 #include <android/log.h>
 #include <log/log_time.h>
 #include <private/android_filesystem_config.h>
 #include <utils/FastStrcmp.h>

 #include "LogBufferElement.h"
 #include "LogUtils.h"

 #define log_id_for_each(i) \
     for (log_id_t i = LOG_ID_MIN; (i) < LOG_ID_MAX; (i) = (log_id_t)((i) + 1))

 class LogStatistics;

 template <typename TKey, typename TEntry>
 class LogHashtable {
     std::unordered_map<TKey, TEntry> map;

     size_t bucket_size() const {
         size_t count = 0;
         for (size_t idx = 0; idx < map.bucket_count(); ++idx) {
             size_t bucket_size = map.bucket_size(idx);
             if (bucket_size == 0) bucket_size = 1;
             count += bucket_size;
         }
         float load_factor = map.max_load_factor();
         if (load_factor < 1.0) return count;
         return count * load_factor;
     }

     static const size_t unordered_map_per_entry_overhead = sizeof(void*);
     static const size_t unordered_map_bucket_overhead = sizeof(void*);

    public:
     size_t size() const {
         return map.size();
     }

     // Estimate unordered_map memory usage.
     size_t sizeOf() const {
         return sizeof(*this) +
                (size() * (sizeof(TEntry) + unordered_map_per_entry_overhead)) +
                (bucket_size() * sizeof(size_t) + unordered_map_bucket_overhead);
     }

     typedef typename std::unordered_map<TKey, TEntry>::iterator iterator;
     typedef
         typename std::unordered_map<TKey, TEntry>::const_iterator const_iterator;

     // Returns a sorted array of up to len highest entries sorted by size.  If fewer than len
     // entries are found, their positions are set to nullptr.
     template <size_t len>
     void MaxEntries(uid_t uid, pid_t pid, std::array<const TEntry*, len>* out) const {
         auto& retval = *out;
         retval.fill(nullptr);
         for (const_iterator it = map.begin(); it != map.end(); ++it) {
             const TEntry& entry = it->second;

             if ((uid != AID_ROOT) && (uid != entry.getUid())) {
                 continue;
             }
             if (pid && entry.getPid() && (pid != entry.getPid())) {
                 continue;
             }

             size_t sizes = entry.getSizes();
             ssize_t index = len - 1;
             while ((!retval[index] || (sizes > retval[index]->getSizes())) &&
                    (--index >= 0))
                 ;
             if (++index < (ssize_t)len) {
                 size_t num = len - index - 1;
                 if (num) {
                     memmove(&retval[index + 1], &retval[index],
                             num * sizeof(retval[0]));
                 }
                 retval[index] = &entry;
             }
         }
     }

     inline iterator add(const TKey& key, const LogBufferElement* element) {
         iterator it = map.find(key);
         if (it == map.end()) {
             it = map.insert(std::make_pair(key, TEntry(element))).first;
         } else {
             it->second.add(element);
         }
         return it;
     }

     inline iterator add(TKey key) {
         iterator it = map.find(key);
         if (it == map.end()) {
             it = map.insert(std::make_pair(key, TEntry(key))).first;
         } else {
             it->second.add(key);
         }
         return it;
     }

     void subtract(TKey&& key, const LogBufferElement* element) {
         iterator it = map.find(std::move(key));
         if ((it != map.end()) && it->second.subtract(element)) {
             map.erase(it);
         }
     }

     void subtract(const TKey& key, const LogBufferElement* element) {
         iterator it = map.find(key);
         if ((it != map.end()) && it->second.subtract(element)) {
             map.erase(it);
         }
     }

     inline void drop(TKey key, const LogBufferElement* element) {
         iterator it = map.find(key);
         if (it != map.end()) {
             it->second.drop(element);
         }
     }

     inline iterator begin() {
         return map.begin();
     }
     inline const_iterator begin() const {
         return map.begin();
     }
     inline iterator end() {
         return map.end();
     }
     inline const_iterator end() const {
         return map.end();
     }
 };

 namespace EntryBaseConstants {
 static constexpr size_t pruned_len = 14;
 static constexpr size_t total_len = 80;
 }

 struct EntryBase {
     size_t size;

     EntryBase() : size(0) {
     }
     explicit EntryBase(const LogBufferElement* element)
         : size(element->getMsgLen()) {
     }

     size_t getSizes() const {
         return size;
     }

     inline void add(const LogBufferElement* element) {
         size += element->getMsgLen();
     }
     inline bool subtract(const LogBufferElement* element) {
         size -= element->getMsgLen();
         return !size;
     }

     static std::string formatLine(const std::string& name,
                                   const std::string& size,
                                   const std::string& pruned) {
         ssize_t drop_len =
             std::max(pruned.length() + 1, EntryBaseConstants::pruned_len);
         ssize_t size_len =
             std::max(size.length() + 1, EntryBaseConstants::total_len -
                                             name.length() - drop_len - 1);

         std::string ret = android::base::StringPrintf(
             "%s%*s%*s", name.c_str(), (int)size_len, size.c_str(),
             (int)drop_len, pruned.c_str());
         // remove any trailing spaces
         size_t pos = ret.size();
         size_t len = 0;
         while (pos && isspace(ret[--pos])) ++len;
         if (len) ret.erase(pos + 1, len);
         return ret + "\n";
     }
 };

 struct EntryBaseDropped : public EntryBase {
     size_t dropped;

     EntryBaseDropped() : dropped(0) {
     }
     explicit EntryBaseDropped(const LogBufferElement* element)
         : EntryBase(element), dropped(element->getDropped()) {
     }

     size_t getDropped() const {
         return dropped;
     }

     inline void add(const LogBufferElement* element) {
         dropped += element->getDropped();
         EntryBase::add(element);
     }
     inline bool subtract(const LogBufferElement* element) {
         dropped -= element->getDropped();
         return EntryBase::subtract(element) && !dropped;
     }
     inline void drop(const LogBufferElement* element) {
         dropped += 1;
         EntryBase::subtract(element);
     }
 };

 struct UidEntry : public EntryBaseDropped {
     const uid_t uid;
     pid_t pid;

     explicit UidEntry(const LogBufferElement* element)
         : EntryBaseDropped(element),
           uid(element->getUid()),
           pid(element->getPid()) {
     }

     inline const uid_t& getKey() const {
         return uid;
     }
     inline const uid_t& getUid() const {
         return getKey();
     }
     inline const pid_t& getPid() const {
         return pid;
     }

     inline void add(const LogBufferElement* element) {
         if (pid != element->getPid()) {
             pid = -1;
         }
         EntryBaseDropped::add(element);
     }

     std::string formatHeader(const std::string& name, log_id_t id) const;
     std::string format(const LogStatistics& stat, log_id_t id) const;
 };

 namespace android {
 uid_t pidToUid(pid_t pid);
 }

 struct PidEntry : public EntryBaseDropped {
     const pid_t pid;
     uid_t uid;
     char* name;

     explicit PidEntry(pid_t pid)
         : EntryBaseDropped(),
           pid(pid),
           uid(android::pidToUid(pid)),
           name(android::pidToName(pid)) {
     }
     explicit PidEntry(const LogBufferElement* element)
         : EntryBaseDropped(element),
           pid(element->getPid()),
           uid(element->getUid()),
           name(android::pidToName(pid)) {
     }
     PidEntry(const PidEntry& element)
         : EntryBaseDropped(element),
           pid(element.pid),
           uid(element.uid),
           name(element.name ? strdup(element.name) : nullptr) {
     }
     ~PidEntry() {
         free(name);
     }

     const pid_t& getKey() const {
         return pid;
     }
     const pid_t& getPid() const {
         return getKey();
     }
     const uid_t& getUid() const {
         return uid;
     }
     const char* getName() const {
         return name;
     }

     inline void add(pid_t newPid) {
         if (name && !fastcmp<strncmp>(name, "zygote", 6)) {
             free(name);
             name = nullptr;
         }
         if (!name) {
             name = android::pidToName(newPid);
         }
     }

     inline void add(const LogBufferElement* element) {
         uid_t incomingUid = element->getUid();
         if (getUid() != incomingUid) {
             uid = incomingUid;
             free(name);
             name = android::pidToName(element->getPid());
         } else {
             add(element->getPid());
         }
         EntryBaseDropped::add(element);
     }

     std::string formatHeader(const std::string& name, log_id_t id) const;
     std::string format(const LogStatistics& stat, log_id_t id) const;
 };

 struct TidEntry : public EntryBaseDropped {
     const pid_t tid;
     pid_t pid;
     uid_t uid;
     char* name;

     TidEntry(pid_t tid, pid_t pid)
         : EntryBaseDropped(),
           tid(tid),
           pid(pid),
           uid(android::pidToUid(tid)),
           name(android::tidToName(tid)) {
     }
     explicit TidEntry(const LogBufferElement* element)
         : EntryBaseDropped(element),
           tid(element->getTid()),
           pid(element->getPid()),
           uid(element->getUid()),
           name(android::tidToName(tid)) {
     }
     TidEntry(const TidEntry& element)
         : EntryBaseDropped(element),
           tid(element.tid),
           pid(element.pid),
           uid(element.uid),
           name(element.name ? strdup(element.name) : nullptr) {
     }
     ~TidEntry() {
         free(name);
     }

     const pid_t& getKey() const {
         return tid;
     }
     const pid_t& getTid() const {
         return getKey();
     }
     const pid_t& getPid() const {
         return pid;
     }
     const uid_t& getUid() const {
         return uid;
     }
     const char* getName() const {
         return name;
     }

     inline void add(pid_t incomingTid) {
         if (name && !fastcmp<strncmp>(name, "zygote", 6)) {
             free(name);
             name = nullptr;
         }
         if (!name) {
             name = android::tidToName(incomingTid);
         }
     }

     inline void add(const LogBufferElement* element) {
         uid_t incomingUid = element->getUid();
         pid_t incomingPid = element->getPid();
         if ((getUid() != incomingUid) || (getPid() != incomingPid)) {
             uid = incomingUid;
             pid = incomingPid;
             free(name);
             name = android::tidToName(element->getTid());
         } else {
             add(element->getTid());
         }
         EntryBaseDropped::add(element);
     }

     std::string formatHeader(const std::string& name, log_id_t id) const;
     std::string format(const LogStatistics& stat, log_id_t id) const;
 };

 struct TagEntry : public EntryBaseDropped {
     const uint32_t tag;
     pid_t pid;
     uid_t uid;

     explicit TagEntry(const LogBufferElement* element)
         : EntryBaseDropped(element),
           tag(element->getTag()),
           pid(element->getPid()),
           uid(element->getUid()) {
     }

     const uint32_t& getKey() const {
         return tag;
     }
     const pid_t& getPid() const {
         return pid;
     }
     const uid_t& getUid() const {
         return uid;
     }
     const char* getName() const {
         return android::tagToName(tag);
     }

     inline void add(const LogBufferElement* element) {
         if (uid != element->getUid()) {
             uid = -1;
         }
         if (pid != element->getPid()) {
             pid = -1;
         }
         EntryBaseDropped::add(element);
     }

     std::string formatHeader(const std::string& name, log_id_t id) const;
     std::string format(const LogStatistics& stat, log_id_t id) const;
 };

 struct TagNameKey {
     std::string* alloc;
     std::string_view name;  // Saves space if const char*

     explicit TagNameKey(const LogBufferElement* element)
         : alloc(nullptr), name("", strlen("")) {
         if (element->isBinary()) {
             uint32_t tag = element->getTag();
             if (tag) {
                 const char* cp = android::tagToName(tag);
                 if (cp) {
                     name = std::string_view(cp, strlen(cp));
                     return;
                 }
             }
             alloc = new std::string(
                 android::base::StringPrintf("[%" PRIu32 "]", tag));
             if (!alloc) return;
             name = std::string_view(alloc->c_str(), alloc->size());
             return;
         }
         const char* msg = element->getMsg();
         if (!msg) {
             name = std::string_view("chatty", strlen("chatty"));
             return;
         }
         ++msg;
         uint16_t len = element->getMsgLen();
         len = (len <= 1) ? 0 : strnlen(msg, len - 1);
         if (!len) {
             name = std::string_view("<NULL>", strlen("<NULL>"));
             return;
         }
         alloc = new std::string(msg, len);
         if (!alloc) return;
         name = std::string_view(alloc->c_str(), alloc->size());
     }

     explicit TagNameKey(TagNameKey&& rval) noexcept
         : alloc(rval.alloc), name(rval.name.data(), rval.name.length()) {
         rval.alloc = nullptr;
     }

     explicit TagNameKey(const TagNameKey& rval)
         : alloc(rval.alloc ? new std::string(*rval.alloc) : nullptr),
           name(alloc ? alloc->data() : rval.name.data(), rval.name.length()) {
     }

     ~TagNameKey() {
         if (alloc) delete alloc;
     }

     operator const std::string_view() const {
         return name;
     }

     const char* data() const {
         return name.data();
     }
     size_t length() const {
         return name.length();
     }

     bool operator==(const TagNameKey& rval) const {
         if (length() != rval.length()) return false;
         if (length() == 0) return true;
         return fastcmp<strncmp>(data(), rval.data(), length()) == 0;
     }
     bool operator!=(const TagNameKey& rval) const {
         return !(*this == rval);
     }

     size_t getAllocLength() const {
         return alloc ? alloc->length() + 1 + sizeof(std::string) : 0;
     }
 };

 // Hash for TagNameKey
 template <>
 struct std::hash<TagNameKey>
     : public std::unary_function<const TagNameKey&, size_t> {
     size_t operator()(const TagNameKey& __t) const noexcept {
         if (!__t.length()) return 0;
         return std::hash<std::string_view>()(std::string_view(__t));
     }
 };

 struct TagNameEntry : public EntryBase {
     pid_t tid;
     pid_t pid;
     uid_t uid;
     TagNameKey name;

     explicit TagNameEntry(const LogBufferElement* element)
         : EntryBase(element),
           tid(element->getTid()),
           pid(element->getPid()),
           uid(element->getUid()),
           name(element) {
     }

     const TagNameKey& getKey() const {
         return name;
     }
     const pid_t& getTid() const {
         return tid;
     }
     const pid_t& getPid() const {
         return pid;
     }
     const uid_t& getUid() const {
         return uid;
     }
     const char* getName() const {
         return name.data();
     }
     size_t getNameAllocLength() const {
         return name.getAllocLength();
     }

     inline void add(const LogBufferElement* element) {
         if (uid != element->getUid()) {
             uid = -1;
         }
         if (pid != element->getPid()) {
             pid = -1;
         }
         if (tid != element->getTid()) {
             tid = -1;
         }
         EntryBase::add(element);
     }

     std::string formatHeader(const std::string& name, log_id_t id) const;
     std::string format(const LogStatistics& stat, log_id_t id) const;
 };

 // Log Statistics
 class LogStatistics {
     friend UidEntry;
     friend PidEntry;
     friend TidEntry;

     size_t mSizes[LOG_ID_MAX] GUARDED_BY(lock_);
     size_t mElements[LOG_ID_MAX] GUARDED_BY(lock_);
     size_t mDroppedElements[LOG_ID_MAX] GUARDED_BY(lock_);
     size_t mSizesTotal[LOG_ID_MAX] GUARDED_BY(lock_);
     size_t mElementsTotal[LOG_ID_MAX] GUARDED_BY(lock_);
     log_time mOldest[LOG_ID_MAX] GUARDED_BY(lock_);
     log_time mNewest[LOG_ID_MAX] GUARDED_BY(lock_);
     log_time mNewestDropped[LOG_ID_MAX] GUARDED_BY(lock_);
     static std::atomic<size_t> SizesTotal;
     bool enable;

     // uid to size list
     typedef LogHashtable<uid_t, UidEntry> uidTable_t;
     uidTable_t uidTable[LOG_ID_MAX] GUARDED_BY(lock_);

     // pid of system to size list
     typedef LogHashtable<pid_t, PidEntry> pidSystemTable_t;
     pidSystemTable_t pidSystemTable[LOG_ID_MAX] GUARDED_BY(lock_);

     // pid to uid list
     typedef LogHashtable<pid_t, PidEntry> pidTable_t;
     pidTable_t pidTable GUARDED_BY(lock_);

     // tid to uid list
     typedef LogHashtable<pid_t, TidEntry> tidTable_t;
     tidTable_t tidTable GUARDED_BY(lock_);

     // tag list
     typedef LogHashtable<uint32_t, TagEntry> tagTable_t;
     tagTable_t tagTable GUARDED_BY(lock_);

     // security tag list
     tagTable_t securityTagTable GUARDED_BY(lock_);

     // global tag list
     typedef LogHashtable<TagNameKey, TagNameEntry> tagNameTable_t;
     tagNameTable_t tagNameTable;

     size_t sizeOf() const REQUIRES(lock_) {
         size_t size = sizeof(*this) + pidTable.sizeOf() + tidTable.sizeOf() +
                       tagTable.sizeOf() + securityTagTable.sizeOf() +
                       tagNameTable.sizeOf() +
                       (pidTable.size() * sizeof(pidTable_t::iterator)) +
                       (tagTable.size() * sizeof(tagTable_t::iterator));
         for (auto it : pidTable) {
             const char* name = it.second.getName();
             if (name) size += strlen(name) + 1;
         }
         for (auto it : tidTable) {
             const char* name = it.second.getName();
             if (name) size += strlen(name) + 1;
         }
         for (auto it : tagNameTable) size += it.second.getNameAllocLength();
         log_id_for_each(id) {
             size += uidTable[id].sizeOf();
             size += uidTable[id].size() * sizeof(uidTable_t::iterator);
             size += pidSystemTable[id].sizeOf();
             size +=
                 pidSystemTable[id].size() * sizeof(pidSystemTable_t::iterator);
         }
         return size;
     }

   public:
     LogStatistics(bool enable_statistics);

     void AddTotal(LogBufferElement* entry) EXCLUDES(lock_);
     void Add(LogBufferElement* entry) EXCLUDES(lock_);
     void Subtract(LogBufferElement* entry) EXCLUDES(lock_);
     // entry->setDropped(1) must follow this call
     void Drop(LogBufferElement* entry) EXCLUDES(lock_);
     // Correct for coalescing two entries referencing dropped content
     void Erase(LogBufferElement* element) EXCLUDES(lock_) {
         auto lock = std::lock_guard{lock_};
         log_id_t log_id = element->getLogId();
         --mElements[log_id];
         --mDroppedElements[log_id];
     }

     void WorstTwoUids(log_id id, size_t threshold, int* worst, size_t* worst_sizes,
                       size_t* second_worst_sizes) const EXCLUDES(lock_);
     void WorstTwoTags(size_t threshold, int* worst, size_t* worst_sizes,
                       size_t* second_worst_sizes) const EXCLUDES(lock_);
     void WorstTwoSystemPids(log_id id, size_t worst_uid_sizes, int* worst,
                             size_t* second_worst_sizes) const EXCLUDES(lock_);

     bool ShouldPrune(log_id id, unsigned long max_size, unsigned long* prune_rows) const
             EXCLUDES(lock_);

     // Snapshot of the sizes for a given log buffer.
     size_t Sizes(log_id_t id) const EXCLUDES(lock_) {
         auto lock = std::lock_guard{lock_};
         return mSizes[id];
     }
     // TODO: Get rid of this entirely.
     static size_t sizesTotal() {
         return SizesTotal;
     }

     std::string Format(uid_t uid, pid_t pid, unsigned int logMask) const EXCLUDES(lock_);

     const char* PidToName(pid_t pid) const EXCLUDES(lock_);
     uid_t PidToUid(pid_t pid) EXCLUDES(lock_);
     const char* UidToName(uid_t uid) const EXCLUDES(lock_);

   private:
     template <typename TKey, typename TEntry>
     void WorstTwoWithThreshold(const LogHashtable<TKey, TEntry>& table, size_t threshold,
                                int* worst, size_t* worst_sizes, size_t* second_worst_sizes) const;
     template <typename TKey, typename TEntry>
     std::string FormatTable(const LogHashtable<TKey, TEntry>& table, uid_t uid, pid_t pid,
                             const std::string& name = std::string(""),
                             log_id_t id = LOG_ID_MAX) const REQUIRES(lock_);
     void FormatTmp(const char* nameTmp, uid_t uid, std::string& name, std::string& size,
                    size_t nameLen) const REQUIRES(lock_);
     const char* UidToNameLocked(uid_t uid) const REQUIRES(lock_);

     mutable std::mutex lock_;
 };
	/*
	* Copyright (C) 2014 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.
	*/

	#pragma once

	#include <ctype.h>
	#include <inttypes.h>
	#include <stdint.h>
	#include <stdlib.h>
	#include <string.h>
	#include <sys/types.h>

	#include <algorithm> // std::max
	#include <array>
	#include <memory>
	#include <mutex>
	#include <string>
	#include <string_view>
	#include <unordered_map>

	#include <android-base/stringprintf.h>
	#include <android-base/thread_annotations.h>
	#include <android/log.h>
	#include <log/log_time.h>
	#include <private/android_filesystem_config.h>
	#include <utils/FastStrcmp.h>

	#include "LogBufferElement.h"
	#include "LogUtils.h"

	#define log_id_for_each(i) \
	for (log_id_t i = LOG_ID_MIN; (i) < LOG_ID_MAX; (i) = (log_id_t)((i) + 1))

	class LogStatistics;

	template <typename TKey, typename TEntry>
	class LogHashtable {
	std::unordered_map<TKey, TEntry> map;

	size_t bucket_size() const {
	size_t count = 0;
	for (size_t idx = 0; idx < map.bucket_count(); ++idx) {
	size_t bucket_size = map.bucket_size(idx);
	if (bucket_size == 0) bucket_size = 1;
	count += bucket_size;
	}
	float load_factor = map.max_load_factor();
	if (load_factor < 1.0) return count;
	return count * load_factor;
	}

	static const size_t unordered_map_per_entry_overhead = sizeof(void*);
	static const size_t unordered_map_bucket_overhead = sizeof(void*);

	public:
	size_t size() const {
	return map.size();
	}

	// Estimate unordered_map memory usage.
	size_t sizeOf() const {
	return sizeof(*this) +
	(size() * (sizeof(TEntry) + unordered_map_per_entry_overhead)) +
	(bucket_size() * sizeof(size_t) + unordered_map_bucket_overhead);
	}

	typedef typename std::unordered_map<TKey, TEntry>::iterator iterator;
	typedef
	typename std::unordered_map<TKey, TEntry>::const_iterator const_iterator;

	// Returns a sorted array of up to len highest entries sorted by size. If fewer than len
	// entries are found, their positions are set to nullptr.
	template <size_t len>
	void MaxEntries(uid_t uid, pid_t pid, std::array<const TEntry, len> out) const {
	auto& retval = *out;
	retval.fill(nullptr);
	for (const_iterator it = map.begin(); it != map.end(); ++it) {
	const TEntry& entry = it->second;

	if ((uid != AID_ROOT) && (uid != entry.getUid())) {
	continue;
	}
	if (pid && entry.getPid() && (pid != entry.getPid())) {
	continue;
	}

	size_t sizes = entry.getSizes();
	ssize_t index = len - 1;
	while ((!retval[index] \|\| (sizes > retval[index]->getSizes())) &&
	(--index >= 0))
	;
	if (++index < (ssize_t)len) {
	size_t num = len - index - 1;
	if (num) {
	memmove(&retval[index + 1], &retval[index],
	num * sizeof(retval[0]));
	}
	retval[index] = &entry;
	}
	}
	}

	inline iterator add(const TKey& key, const LogBufferElement* element) {
	iterator it = map.find(key);
	if (it == map.end()) {
	it = map.insert(std::make_pair(key, TEntry(element))).first;
	} else {
	it->second.add(element);
	}
	return it;
	}

	inline iterator add(TKey key) {
	iterator it = map.find(key);
	if (it == map.end()) {
	it = map.insert(std::make_pair(key, TEntry(key))).first;
	} else {
	it->second.add(key);
	}
	return it;
	}

	void subtract(TKey&& key, const LogBufferElement* element) {
	iterator it = map.find(std::move(key));
	if ((it != map.end()) && it->second.subtract(element)) {
	map.erase(it);
	}
	}

	void subtract(const TKey& key, const LogBufferElement* element) {
	iterator it = map.find(key);
	if ((it != map.end()) && it->second.subtract(element)) {
	map.erase(it);
	}
	}

	inline void drop(TKey key, const LogBufferElement* element) {
	iterator it = map.find(key);
	if (it != map.end()) {
	it->second.drop(element);
	}
	}

	inline iterator begin() {
	return map.begin();
	}
	inline const_iterator begin() const {
	return map.begin();
	}
	inline iterator end() {
	return map.end();
	}
	inline const_iterator end() const {
	return map.end();
	}
	};

	namespace EntryBaseConstants {
	static constexpr size_t pruned_len = 14;
	static constexpr size_t total_len = 80;
	}

	struct EntryBase {
	size_t size;

	EntryBase() : size(0) {
	}
	explicit EntryBase(const LogBufferElement* element)
	: size(element->getMsgLen()) {
	}

	size_t getSizes() const {
	return size;
	}

	inline void add(const LogBufferElement* element) {
	size += element->getMsgLen();
	}
	inline bool subtract(const LogBufferElement* element) {
	size -= element->getMsgLen();
	return !size;
	}

	static std::string formatLine(const std::string& name,
	const std::string& size,
	const std::string& pruned) {
	ssize_t drop_len =
	std::max(pruned.length() + 1, EntryBaseConstants::pruned_len);
	ssize_t size_len =
	std::max(size.length() + 1, EntryBaseConstants::total_len -
	name.length() - drop_len - 1);

	std::string ret = android::base::StringPrintf(
	"%s%s%s", name.c_str(), (int)size_len, size.c_str(),
	(int)drop_len, pruned.c_str());
	// remove any trailing spaces
	size_t pos = ret.size();
	size_t len = 0;
	while (pos && isspace(ret[--pos])) ++len;
	if (len) ret.erase(pos + 1, len);
	return ret + "\n";
	}
	};

	struct EntryBaseDropped : public EntryBase {
	size_t dropped;

	EntryBaseDropped() : dropped(0) {
	}
	explicit EntryBaseDropped(const LogBufferElement* element)
	: EntryBase(element), dropped(element->getDropped()) {
	}

	size_t getDropped() const {
	return dropped;
	}

	inline void add(const LogBufferElement* element) {
	dropped += element->getDropped();
	EntryBase::add(element);
	}
	inline bool subtract(const LogBufferElement* element) {
	dropped -= element->getDropped();
	return EntryBase::subtract(element) && !dropped;
	}
	inline void drop(const LogBufferElement* element) {
	dropped += 1;
	EntryBase::subtract(element);
	}
	};

	struct UidEntry : public EntryBaseDropped {
	const uid_t uid;
	pid_t pid;

	explicit UidEntry(const LogBufferElement* element)
	: EntryBaseDropped(element),
	uid(element->getUid()),
	pid(element->getPid()) {
	}

	inline const uid_t& getKey() const {
	return uid;
	}
	inline const uid_t& getUid() const {
	return getKey();
	}
	inline const pid_t& getPid() const {
	return pid;
	}

	inline void add(const LogBufferElement* element) {
	if (pid != element->getPid()) {
	pid = -1;
	}
	EntryBaseDropped::add(element);
	}

	std::string formatHeader(const std::string& name, log_id_t id) const;
	std::string format(const LogStatistics& stat, log_id_t id) const;
	};

	namespace android {
	uid_t pidToUid(pid_t pid);
	}

	struct PidEntry : public EntryBaseDropped {
	const pid_t pid;
	uid_t uid;
	char* name;

	explicit PidEntry(pid_t pid)
	: EntryBaseDropped(),
	pid(pid),
	uid(android::pidToUid(pid)),
	name(android::pidToName(pid)) {
	}
	explicit PidEntry(const LogBufferElement* element)
	: EntryBaseDropped(element),
	pid(element->getPid()),
	uid(element->getUid()),
	name(android::pidToName(pid)) {
	}
	PidEntry(const PidEntry& element)
	: EntryBaseDropped(element),
	pid(element.pid),
	uid(element.uid),
	name(element.name ? strdup(element.name) : nullptr) {
	}
	~PidEntry() {
	free(name);
	}

	const pid_t& getKey() const {
	return pid;
	}
	const pid_t& getPid() const {
	return getKey();
	}
	const uid_t& getUid() const {
	return uid;
	}
	const char* getName() const {
	return name;
	}

	inline void add(pid_t newPid) {
	if (name && !fastcmp<strncmp>(name, "zygote", 6)) {
	free(name);
	name = nullptr;
	}
	if (!name) {
	name = android::pidToName(newPid);
	}
	}

	inline void add(const LogBufferElement* element) {
	uid_t incomingUid = element->getUid();
	if (getUid() != incomingUid) {
	uid = incomingUid;
	free(name);
	name = android::pidToName(element->getPid());
	} else {
	add(element->getPid());
	}
	EntryBaseDropped::add(element);
	}

	std::string formatHeader(const std::string& name, log_id_t id) const;
	std::string format(const LogStatistics& stat, log_id_t id) const;
	};

	struct TidEntry : public EntryBaseDropped {
	const pid_t tid;
	pid_t pid;
	uid_t uid;
	char* name;

	TidEntry(pid_t tid, pid_t pid)
	: EntryBaseDropped(),
	tid(tid),
	pid(pid),
	uid(android::pidToUid(tid)),
	name(android::tidToName(tid)) {
	}
	explicit TidEntry(const LogBufferElement* element)
	: EntryBaseDropped(element),
	tid(element->getTid()),
	pid(element->getPid()),
	uid(element->getUid()),
	name(android::tidToName(tid)) {
	}
	TidEntry(const TidEntry& element)
	: EntryBaseDropped(element),
	tid(element.tid),
	pid(element.pid),
	uid(element.uid),
	name(element.name ? strdup(element.name) : nullptr) {
	}
	~TidEntry() {
	free(name);
	}

	const pid_t& getKey() const {
	return tid;
	}
	const pid_t& getTid() const {
	return getKey();
	}
	const pid_t& getPid() const {
	return pid;
	}
	const uid_t& getUid() const {
	return uid;
	}
	const char* getName() const {
	return name;
	}

	inline void add(pid_t incomingTid) {
	if (name && !fastcmp<strncmp>(name, "zygote", 6)) {
	free(name);
	name = nullptr;
	}
	if (!name) {
	name = android::tidToName(incomingTid);
	}
	}

	inline void add(const LogBufferElement* element) {
	uid_t incomingUid = element->getUid();
	pid_t incomingPid = element->getPid();
	if ((getUid() != incomingUid) \|\| (getPid() != incomingPid)) {
	uid = incomingUid;
	pid = incomingPid;
	free(name);
	name = android::tidToName(element->getTid());
	} else {
	add(element->getTid());
	}
	EntryBaseDropped::add(element);
	}

	std::string formatHeader(const std::string& name, log_id_t id) const;
	std::string format(const LogStatistics& stat, log_id_t id) const;
	};

	struct TagEntry : public EntryBaseDropped {
	const uint32_t tag;
	pid_t pid;
	uid_t uid;

	explicit TagEntry(const LogBufferElement* element)
	: EntryBaseDropped(element),
	tag(element->getTag()),
	pid(element->getPid()),
	uid(element->getUid()) {
	}

	const uint32_t& getKey() const {
	return tag;
	}
	const pid_t& getPid() const {
	return pid;
	}
	const uid_t& getUid() const {
	return uid;
	}
	const char* getName() const {
	return android::tagToName(tag);
	}

	inline void add(const LogBufferElement* element) {
	if (uid != element->getUid()) {
	uid = -1;
	}
	if (pid != element->getPid()) {
	pid = -1;
	}
	EntryBaseDropped::add(element);
	}

	std::string formatHeader(const std::string& name, log_id_t id) const;
	std::string format(const LogStatistics& stat, log_id_t id) const;
	};

	struct TagNameKey {
	std::string* alloc;
	std::string_view name; // Saves space if const char*

	explicit TagNameKey(const LogBufferElement* element)
	: alloc(nullptr), name("", strlen("")) {
	if (element->isBinary()) {
	uint32_t tag = element->getTag();
	if (tag) {
	const char* cp = android::tagToName(tag);
	if (cp) {
	name = std::string_view(cp, strlen(cp));
	return;
	}
	}
	alloc = new std::string(
	android::base::StringPrintf("[%" PRIu32 "]", tag));
	if (!alloc) return;
	name = std::string_view(alloc->c_str(), alloc->size());
	return;
	}
	const char* msg = element->getMsg();
	if (!msg) {
	name = std::string_view("chatty", strlen("chatty"));
	return;
	}
	++msg;
	uint16_t len = element->getMsgLen();
	len = (len <= 1) ? 0 : strnlen(msg, len - 1);
	if (!len) {
	name = std::string_view("<NULL>", strlen("<NULL>"));
	return;
	}
	alloc = new std::string(msg, len);
	if (!alloc) return;
	name = std::string_view(alloc->c_str(), alloc->size());
	}

	explicit TagNameKey(TagNameKey&& rval) noexcept
	: alloc(rval.alloc), name(rval.name.data(), rval.name.length()) {
	rval.alloc = nullptr;
	}

	explicit TagNameKey(const TagNameKey& rval)
	: alloc(rval.alloc ? new std::string(*rval.alloc) : nullptr),
	name(alloc ? alloc->data() : rval.name.data(), rval.name.length()) {
	}

	~TagNameKey() {
	if (alloc) delete alloc;
	}

	operator const std::string_view() const {
	return name;
	}

	const char* data() const {
	return name.data();
	}
	size_t length() const {
	return name.length();
	}

	bool operator==(const TagNameKey& rval) const {
	if (length() != rval.length()) return false;
	if (length() == 0) return true;
	return fastcmp<strncmp>(data(), rval.data(), length()) == 0;
	}
	bool operator!=(const TagNameKey& rval) const {
	return !(*this == rval);
	}

	size_t getAllocLength() const {
	return alloc ? alloc->length() + 1 + sizeof(std::string) : 0;
	}
	};

	// Hash for TagNameKey
	template <>
	struct std::hash<TagNameKey>
	: public std::unary_function<const TagNameKey&, size_t> {
	size_t operator()(const TagNameKey& __t) const noexcept {
	if (!__t.length()) return 0;
	return std::hash<std::string_view>()(std::string_view(__t));
	}
	};

	struct TagNameEntry : public EntryBase {
	pid_t tid;
	pid_t pid;
	uid_t uid;
	TagNameKey name;

	explicit TagNameEntry(const LogBufferElement* element)
	: EntryBase(element),
	tid(element->getTid()),
	pid(element->getPid()),
	uid(element->getUid()),
	name(element) {
	}

	const TagNameKey& getKey() const {
	return name;
	}
	const pid_t& getTid() const {
	return tid;
	}
	const pid_t& getPid() const {
	return pid;
	}
	const uid_t& getUid() const {
	return uid;
	}
	const char* getName() const {
	return name.data();
	}
	size_t getNameAllocLength() const {
	return name.getAllocLength();
	}

	inline void add(const LogBufferElement* element) {
	if (uid != element->getUid()) {
	uid = -1;
	}
	if (pid != element->getPid()) {
	pid = -1;
	}
	if (tid != element->getTid()) {
	tid = -1;
	}
	EntryBase::add(element);
	}

	std::string formatHeader(const std::string& name, log_id_t id) const;
	std::string format(const LogStatistics& stat, log_id_t id) const;
	};

	// Log Statistics
	class LogStatistics {
	friend UidEntry;
	friend PidEntry;
	friend TidEntry;

	size_t mSizes[LOG_ID_MAX] GUARDED_BY(lock_);
	size_t mElements[LOG_ID_MAX] GUARDED_BY(lock_);
	size_t mDroppedElements[LOG_ID_MAX] GUARDED_BY(lock_);
	size_t mSizesTotal[LOG_ID_MAX] GUARDED_BY(lock_);
	size_t mElementsTotal[LOG_ID_MAX] GUARDED_BY(lock_);
	log_time mOldest[LOG_ID_MAX] GUARDED_BY(lock_);
	log_time mNewest[LOG_ID_MAX] GUARDED_BY(lock_);
	log_time mNewestDropped[LOG_ID_MAX] GUARDED_BY(lock_);
	static std::atomic<size_t> SizesTotal;
	bool enable;

	// uid to size list
	typedef LogHashtable<uid_t, UidEntry> uidTable_t;
	uidTable_t uidTable[LOG_ID_MAX] GUARDED_BY(lock_);

	// pid of system to size list
	typedef LogHashtable<pid_t, PidEntry> pidSystemTable_t;
	pidSystemTable_t pidSystemTable[LOG_ID_MAX] GUARDED_BY(lock_);

	// pid to uid list
	typedef LogHashtable<pid_t, PidEntry> pidTable_t;
	pidTable_t pidTable GUARDED_BY(lock_);

	// tid to uid list
	typedef LogHashtable<pid_t, TidEntry> tidTable_t;
	tidTable_t tidTable GUARDED_BY(lock_);

	// tag list
	typedef LogHashtable<uint32_t, TagEntry> tagTable_t;
	tagTable_t tagTable GUARDED_BY(lock_);

	// security tag list
	tagTable_t securityTagTable GUARDED_BY(lock_);

	// global tag list
	typedef LogHashtable<TagNameKey, TagNameEntry> tagNameTable_t;
	tagNameTable_t tagNameTable;

	size_t sizeOf() const REQUIRES(lock_) {
	size_t size = sizeof(*this) + pidTable.sizeOf() + tidTable.sizeOf() +
	tagTable.sizeOf() + securityTagTable.sizeOf() +
	tagNameTable.sizeOf() +
	(pidTable.size() * sizeof(pidTable_t::iterator)) +
	(tagTable.size() * sizeof(tagTable_t::iterator));
	for (auto it : pidTable) {
	const char* name = it.second.getName();
	if (name) size += strlen(name) + 1;
	}
	for (auto it : tidTable) {
	const char* name = it.second.getName();
	if (name) size += strlen(name) + 1;
	}
	for (auto it : tagNameTable) size += it.second.getNameAllocLength();
	log_id_for_each(id) {
	size += uidTable[id].sizeOf();
	size += uidTable[id].size() * sizeof(uidTable_t::iterator);
	size += pidSystemTable[id].sizeOf();
	size +=
	pidSystemTable[id].size() * sizeof(pidSystemTable_t::iterator);
	}
	return size;
	}

	public:
	LogStatistics(bool enable_statistics);

	void AddTotal(LogBufferElement* entry) EXCLUDES(lock_);
	void Add(LogBufferElement* entry) EXCLUDES(lock_);
	void Subtract(LogBufferElement* entry) EXCLUDES(lock_);
	// entry->setDropped(1) must follow this call
	void Drop(LogBufferElement* entry) EXCLUDES(lock_);
	// Correct for coalescing two entries referencing dropped content
	void Erase(LogBufferElement* element) EXCLUDES(lock_) {
	auto lock = std::lock_guard{lock_};
	log_id_t log_id = element->getLogId();
	--mElements[log_id];
	--mDroppedElements[log_id];
	}

	void WorstTwoUids(log_id id, size_t threshold, int* worst, size_t* worst_sizes,
	size_t* second_worst_sizes) const EXCLUDES(lock_);
	void WorstTwoTags(size_t threshold, int* worst, size_t* worst_sizes,
	size_t* second_worst_sizes) const EXCLUDES(lock_);
	void WorstTwoSystemPids(log_id id, size_t worst_uid_sizes, int* worst,
	size_t* second_worst_sizes) const EXCLUDES(lock_);

	bool ShouldPrune(log_id id, unsigned long max_size, unsigned long* prune_rows) const
	EXCLUDES(lock_);

	// Snapshot of the sizes for a given log buffer.
	size_t Sizes(log_id_t id) const EXCLUDES(lock_) {
	auto lock = std::lock_guard{lock_};
	return mSizes[id];
	}
	// TODO: Get rid of this entirely.
	static size_t sizesTotal() {
	return SizesTotal;
	}

	std::string Format(uid_t uid, pid_t pid, unsigned int logMask) const EXCLUDES(lock_);

	const char* PidToName(pid_t pid) const EXCLUDES(lock_);
	uid_t PidToUid(pid_t pid) EXCLUDES(lock_);
	const char* UidToName(uid_t uid) const EXCLUDES(lock_);

	private:
	template <typename TKey, typename TEntry>
	void WorstTwoWithThreshold(const LogHashtable<TKey, TEntry>& table, size_t threshold,
	int* worst, size_t* worst_sizes, size_t* second_worst_sizes) const;
	template <typename TKey, typename TEntry>
	std::string FormatTable(const LogHashtable<TKey, TEntry>& table, uid_t uid, pid_t pid,
	const std::string& name = std::string(""),
	log_id_t id = LOG_ID_MAX) const REQUIRES(lock_);
	void FormatTmp(const char* nameTmp, uid_t uid, std::string& name, std::string& size,
	size_t nameLen) const REQUIRES(lock_);
	const char* UidToNameLocked(uid_t uid) const REQUIRES(lock_);

	mutable std::mutex lock_;
	};