logd: add Chattiest LOG_TAG statistics

Report global LOG_TAG usage.

Switch NULL to nullptr and use const more accurately.

Test: gTest liblog-unit-tests, logd-unit-tests & logcat-unit-tests
Test: manual: inspect logcat -S results around 'Chattiest TAGs'
Test: logcat -b all -c ; logcat -b all -S ; then confirm clear
Bug: 37254265
Change-Id: I3696c0d8da3ba24f99f670aafba1e45f8cb3ab14

2 files changed, 253 insertions, 23 deletions

diff --git a/logd/LogStatistics.cpp b/logd/LogStatistics.cpp
index 0b6b28cf8..d20d90e58 100644
--- a/logd/LogStatistics.cpp
+++ b/logd/LogStatistics.cpp
@@ -152,6 +152,10 @@ void LogStatistics::add(LogBufferElement* element) {
             tagTable.add(tag, element);
         }
     }
+
+    if (!element->getDropped()) {
+        tagNameTable.add(TagNameKey(element), element);
+    }
 }
 
 void LogStatistics::subtract(LogBufferElement* element) {
@@ -191,6 +195,10 @@ void LogStatistics::subtract(LogBufferElement* element) {
             tagTable.subtract(tag, element);
         }
     }
+
+    if (!element->getDropped()) {
+        tagNameTable.subtract(TagNameKey(element), element);
+    }
 }
 
 // Atomically set an entry to drop
@@ -225,6 +233,8 @@ void LogStatistics::drop(LogBufferElement* element) {
             tagTable.drop(tag, element);
         }
     }
+
+    tagNameTable.subtract(TagNameKey(element), element);
 }
 
 // caller must own and free character string
@@ -505,6 +515,62 @@ std::string TagEntry::format(const LogStatistics& /* stat */,
     return formatLine(name, size, pruned);
 }
 
+std::string TagNameEntry::formatHeader(const std::string& name,
+                                       log_id_t /* id */) const {
+    return formatLine(name, std::string("Size"), std::string("")) +
+           formatLine(std::string("  TID/PID/UID   LOG_TAG NAME"),
+                      std::string("BYTES"), std::string(""));
+}
+
+std::string TagNameEntry::format(const LogStatistics& /* stat */,
+                                 log_id_t /* id */) const {
+    std::string name;
+    pid_t tid = getTid();
+    pid_t pid = getPid();
+    std::string pidstr;
+    if (pid != (pid_t)-1) {
+        pidstr = android::base::StringPrintf("%u", pid);
+        if ((tid != (pid_t)-1) && (tid != pid)) pidstr = "/" + pidstr;
+    }
+    int len = 9 - pidstr.length();
+    if (len < 0) len = 0;
+    if ((tid == (pid_t)-1) || (tid == pid)) {
+        name = android::base::StringPrintf("%*s", len, "");
+    } else {
+        name = android::base::StringPrintf("%*u", len, tid);
+    }
+    name += pidstr;
+    uid_t uid = getUid();
+    if (uid != (uid_t)-1) {
+        name += android::base::StringPrintf("/%u", uid);
+    }
+
+    std::string size = android::base::StringPrintf("%zu", getSizes());
+
+    const char* nameTmp = getName();
+    if (nameTmp) {
+        size_t lenSpace = std::max(16 - name.length(), (size_t)1);
+        size_t len = EntryBaseConstants::total_len -
+                     EntryBaseConstants::pruned_len - size.length() -
+                     name.length() - lenSpace - 2;
+        size_t lenNameTmp = strlen(nameTmp);
+        while ((len < lenNameTmp) && (lenSpace > 1)) {
+            ++len;
+            --lenSpace;
+        }
+        name += android::base::StringPrintf("%*s", (int)lenSpace, "");
+        if (len < lenNameTmp) {
+            name += "...";
+            nameTmp += lenNameTmp - std::max(len - 3, (size_t)1);
+        }
+        name += nameTmp;
+    }
+
+    std::string pruned = "";
+
+    return formatLine(name, size, pruned);
+}
+
 static std::string formatMsec(uint64_t val) {
     static const unsigned subsecDigits = 3;
     static const uint64_t sec = MS_PER_SEC;
@@ -740,6 +806,13 @@ std::string LogStatistics::format(uid_t uid, pid_t pid,
             securityTagTable.format(*this, uid, pid, name, LOG_ID_SECURITY);
     }
 
+    if (enable) {
+        name = "Chattiest TAGs";
+        if (pid) name += android::base::StringPrintf(" for PID %d", pid);
+        name += ":";
+        output += tagNameTable.format(*this, uid, pid, name);
+    }
+
     return output;
 }
 
diff --git a/logd/LogStatistics.h b/logd/LogStatistics.h
index e6f01d64d..945fc0ab6 100644
--- a/logd/LogStatistics.h
+++ b/logd/LogStatistics.h
@@ -18,10 +18,14 @@
 #define _LOGD_LOG_STATISTICS_H__
 
 #include <ctype.h>
+#include <inttypes.h>
+#include <stdint.h>
 #include <stdlib.h>
+#include <string.h>
 #include <sys/types.h>
 
 #include <algorithm>  // std::max
+#include <experimental/string_view>
 #include <memory>
 #include <string>  // std::string
 #include <unordered_map>
@@ -30,6 +34,7 @@
 #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"
@@ -77,7 +82,7 @@ class LogHashtable {
     std::unique_ptr<const TEntry* []> sort(uid_t uid, pid_t pid,
                                            size_t len) const {
         if (!len) {
-            std::unique_ptr<const TEntry* []> sorted(NULL);
+            std::unique_ptr<const TEntry* []> sorted(nullptr);
             return sorted;
         }
 
@@ -112,7 +117,7 @@ class LogHashtable {
         return sorted;
     }
 
-    inline iterator add(TKey key, LogBufferElement* element) {
+    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;
@@ -132,14 +137,21 @@ class LogHashtable {
         return it;
     }
 
-    void subtract(TKey key, LogBufferElement* element) {
+    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, LogBufferElement* element) {
+    inline void drop(TKey key, const LogBufferElement* element) {
         iterator it = map.find(key);
         if (it != map.end()) {
             it->second.drop(element);
@@ -199,17 +211,18 @@ struct EntryBase {
 
     EntryBase() : size(0) {
     }
-    explicit EntryBase(LogBufferElement* element) : size(element->getMsgLen()) {
+    explicit EntryBase(const LogBufferElement* element)
+        : size(element->getMsgLen()) {
     }
 
     size_t getSizes() const {
         return size;
     }
 
-    inline void add(LogBufferElement* element) {
+    inline void add(const LogBufferElement* element) {
         size += element->getMsgLen();
     }
-    inline bool subtract(LogBufferElement* element) {
+    inline bool subtract(const LogBufferElement* element) {
         size -= element->getMsgLen();
         return !size;
     }
@@ -240,7 +253,7 @@ struct EntryBaseDropped : public EntryBase {
 
     EntryBaseDropped() : dropped(0) {
     }
-    explicit EntryBaseDropped(LogBufferElement* element)
+    explicit EntryBaseDropped(const LogBufferElement* element)
         : EntryBase(element), dropped(element->getDropped()) {
     }
 
@@ -248,15 +261,15 @@ struct EntryBaseDropped : public EntryBase {
         return dropped;
     }
 
-    inline void add(LogBufferElement* element) {
+    inline void add(const LogBufferElement* element) {
         dropped += element->getDropped();
         EntryBase::add(element);
     }
-    inline bool subtract(LogBufferElement* element) {
+    inline bool subtract(const LogBufferElement* element) {
         dropped -= element->getDropped();
         return EntryBase::subtract(element) && !dropped;
     }
-    inline void drop(LogBufferElement* element) {
+    inline void drop(const LogBufferElement* element) {
         dropped += 1;
         EntryBase::subtract(element);
     }
@@ -266,7 +279,7 @@ struct UidEntry : public EntryBaseDropped {
     const uid_t uid;
     pid_t pid;
 
-    explicit UidEntry(LogBufferElement* element)
+    explicit UidEntry(const LogBufferElement* element)
         : EntryBaseDropped(element),
           uid(element->getUid()),
           pid(element->getPid()) {
@@ -282,7 +295,7 @@ struct UidEntry : public EntryBaseDropped {
         return pid;
     }
 
-    inline void add(LogBufferElement* element) {
+    inline void add(const LogBufferElement* element) {
         if (pid != element->getPid()) {
             pid = -1;
         }
@@ -308,7 +321,7 @@ struct PidEntry : public EntryBaseDropped {
           uid(android::pidToUid(pid)),
           name(android::pidToName(pid)) {
     }
-    explicit PidEntry(LogBufferElement* element)
+    explicit PidEntry(const LogBufferElement* element)
         : EntryBaseDropped(element),
           pid(element->getPid()),
           uid(element->getUid()),
@@ -318,7 +331,7 @@ struct PidEntry : public EntryBaseDropped {
         : EntryBaseDropped(element),
           pid(element.pid),
           uid(element.uid),
-          name(element.name ? strdup(element.name) : NULL) {
+          name(element.name ? strdup(element.name) : nullptr) {
     }
     ~PidEntry() {
         free(name);
@@ -340,14 +353,14 @@ struct PidEntry : public EntryBaseDropped {
     inline void add(pid_t newPid) {
         if (name && !fastcmp<strncmp>(name, "zygote", 6)) {
             free(name);
-            name = NULL;
+            name = nullptr;
         }
         if (!name) {
             name = android::pidToName(newPid);
         }
     }
 
-    inline void add(LogBufferElement* element) {
+    inline void add(const LogBufferElement* element) {
         uid_t incomingUid = element->getUid();
         if (getUid() != incomingUid) {
             uid = incomingUid;
@@ -376,7 +389,7 @@ struct TidEntry : public EntryBaseDropped {
           uid(android::pidToUid(tid)),
           name(android::tidToName(tid)) {
     }
-    explicit TidEntry(LogBufferElement* element)
+    explicit TidEntry(const LogBufferElement* element)
         : EntryBaseDropped(element),
           tid(element->getTid()),
           pid(element->getPid()),
@@ -388,7 +401,7 @@ struct TidEntry : public EntryBaseDropped {
           tid(element.tid),
           pid(element.pid),
           uid(element.uid),
-          name(element.name ? strdup(element.name) : NULL) {
+          name(element.name ? strdup(element.name) : nullptr) {
     }
     ~TidEntry() {
         free(name);
@@ -413,14 +426,14 @@ struct TidEntry : public EntryBaseDropped {
     inline void add(pid_t incomingTid) {
         if (name && !fastcmp<strncmp>(name, "zygote", 6)) {
             free(name);
-            name = NULL;
+            name = nullptr;
         }
         if (!name) {
             name = android::tidToName(incomingTid);
         }
     }
 
-    inline void add(LogBufferElement* element) {
+    inline void add(const LogBufferElement* element) {
         uid_t incomingUid = element->getUid();
         pid_t incomingPid = element->getPid();
         if ((getUid() != incomingUid) || (getPid() != incomingPid)) {
@@ -443,7 +456,7 @@ struct TagEntry : public EntryBaseDropped {
     pid_t pid;
     uid_t uid;
 
-    explicit TagEntry(LogBufferElement* element)
+    explicit TagEntry(const LogBufferElement* element)
         : EntryBaseDropped(element),
           tag(element->getTag()),
           pid(element->getPid()),
@@ -463,7 +476,7 @@ struct TagEntry : public EntryBaseDropped {
         return android::tagToName(tag);
     }
 
-    inline void add(LogBufferElement* element) {
+    inline void add(const LogBufferElement* element) {
         if (uid != element->getUid()) {
             uid = -1;
         }
@@ -477,6 +490,144 @@ struct TagEntry : public EntryBaseDropped {
     std::string format(const LogStatistics& stat, log_id_t id) const;
 };
 
+struct TagNameKey {
+    std::string* alloc;
+    std::experimental::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::experimental::string_view(cp, strlen(cp));
+                    return;
+                }
+            }
+            alloc = new std::string(
+                android::base::StringPrintf("[%" PRIu32 "]", tag));
+            if (!alloc) return;
+            name = std::experimental::string_view(alloc->c_str(), alloc->size());
+            return;
+        }
+        const char* msg = element->getMsg();
+        if (!msg) {
+            name = std::experimental::string_view("chatty", strlen("chatty"));
+            return;
+        }
+        ++msg;
+        unsigned short len = element->getMsgLen();
+        len = (len <= 1) ? 0 : strnlen(msg, len - 1);
+        if (!len) {
+            name = std::experimental::string_view("<NULL>", strlen("<NULL>"));
+            return;
+        }
+        alloc = new std::string(msg, len);
+        if (!alloc) return;
+        name = std::experimental::string_view(alloc->c_str(), alloc->size());
+    }
+
+    explicit TagNameKey(TagNameKey&& rval)
+        : 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::experimental::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::experimental::string_view>()(
+            std::experimental::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;
+};
+
 template <typename TEntry>
 class LogFindWorst {
     std::unique_ptr<const TEntry* []> sorted;
@@ -550,9 +701,14 @@ class LogStatistics {
     // security tag list
     tagTable_t securityTagTable;
 
+    // global tag list
+    typedef LogHashtable<TagNameKey, TagNameEntry> tagNameTable_t;
+    tagNameTable_t tagNameTable;
+
     size_t sizeOf() const {
         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) {
@@ -563,6 +719,7 @@ class LogStatistics {
             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);