logd: optimize statistics

- Go back to basic requirements
- Simplify
- use hash tables to minimize memory impact

Bug: 19608965
Change-Id: If7becb34354d6415e5c387ecea7d4109a15259c8

1 files changed, 164 insertions, 700 deletions

diff --git a/logd/LogStatistics.cpp b/logd/LogStatistics.cpp
index 5a706899e..19d599c60 100644
--- a/logd/LogStatistics.cpp
+++ b/logd/LogStatistics.cpp
@@ -14,10 +14,12 @@
  * limitations under the License.
  */
 
+#include <algorithm> // std::max
 #include <fcntl.h>
-#include <malloc.h>
-#include <stdarg.h>
-#include <time.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
 
 #include <log/logger.h>
 #include <private/android_filesystem_config.h>
@@ -25,80 +27,21 @@
 
 #include "LogStatistics.h"
 
-PidStatistics::PidStatistics(pid_t pid, char *name)
-        : pid(pid)
-        , mSizesTotal(0)
-        , mElementsTotal(0)
-        , mSizes(0)
-        , mElements(0)
-        , name(name)
-        , mGone(false)
-{ }
-
-#ifdef DO_NOT_ERROR_IF_PIDSTATISTICS_USES_A_COPY_CONSTRUCTOR
-PidStatistics::PidStatistics(const PidStatistics &copy)
-        : pid(copy->pid)
-        , name(copy->name ? strdup(copy->name) : NULL)
-        , mSizesTotal(copy->mSizesTotal)
-        , mElementsTotal(copy->mElementsTotal)
-        , mSizes(copy->mSizes)
-        , mElements(copy->mElements)
-        , mGone(copy->mGone)
-{ }
-#endif
-
-PidStatistics::~PidStatistics() {
-    free(name);
-}
-
-bool PidStatistics::pidGone() {
-    if (mGone || (pid == gone)) {
-        return true;
-    }
-    if (pid == 0) {
-        return false;
-    }
-    if (kill(pid, 0) && (errno != EPERM)) {
-        mGone = true;
-        return true;
-    }
-    return false;
-}
-
-void PidStatistics::setName(char *new_name) {
-    free(name);
-    name = new_name;
-}
-
-void PidStatistics::add(unsigned short size) {
-    mSizesTotal += size;
-    ++mElementsTotal;
-    mSizes += size;
-    ++mElements;
-}
-
-bool PidStatistics::subtract(unsigned short size) {
-    mSizes -= size;
-    --mElements;
-    return (mElements == 0) && pidGone();
-}
-
-void PidStatistics::addTotal(size_t size, size_t element) {
-    if (pid == gone) {
-        mSizesTotal += size;
-        mElementsTotal += element;
+LogStatistics::LogStatistics() {
+    log_id_for_each(id) {
+        mSizes[id] = 0;
+        mElements[id] = 0;
+        mSizesTotal[id] = 0;
+        mElementsTotal[id] = 0;
     }
 }
 
-// must call free to release return value
-//  If only we could sniff our own logs for:
-//   <time> <pid> <pid> E AndroidRuntime: Process: <name>, PID: <pid>
-//  which debuggerd prints as a process is crashing.
-char *PidStatistics::pidToName(pid_t pid) {
+// caller must own and free character string
+char *LogStatistics::pidToName(pid_t pid) {
     char *retval = NULL;
     if (pid == 0) { // special case from auditd for kernel
         retval = strdup("logd.auditd");
-    } else if (pid != gone) {
+    } else {
         char buffer[512];
         snprintf(buffer, sizeof(buffer), "/proc/%u/cmdline", pid);
         int fd = open(buffer, O_RDONLY);
@@ -117,358 +60,105 @@ char *PidStatistics::pidToName(pid_t pid) {
     return retval;
 }
 
-UidStatistics::UidStatistics(uid_t uid)
-        : uid(uid)
-        , mSizes(0)
-        , mElements(0) {
-    Pids.clear();
-}
-
-UidStatistics::~UidStatistics() {
-    PidStatisticsCollection::iterator it;
-    for (it = begin(); it != end();) {
-        delete (*it);
-        it = erase(it);
-    }
-}
+void LogStatistics::add(LogBufferElement *e) {
+    log_id_t log_id = e->getLogId();
+    unsigned short size = e->getMsgLen();
+    mSizes[log_id] += size;
+    ++mElements[log_id];
 
-void UidStatistics::add(unsigned short size, pid_t pid) {
-    mSizes += size;
-    ++mElements;
-
-    PidStatistics *p = NULL;
-    PidStatisticsCollection::iterator last;
-    PidStatisticsCollection::iterator it;
-    for (last = it = begin(); it != end(); last = it, ++it) {
-        p = *it;
-        if (pid == p->getPid()) {
-            p->add(size);
-            return;
-        }
-    }
-    // insert if the gone entry.
-    bool insert_before_last = (last != it) && p && (p->getPid() == p->gone);
-    p = new PidStatistics(pid, pidToName(pid));
-    if (insert_before_last) {
-        insert(last, p);
+    uid_t uid = e->getUid();
+    android::hash_t hash = android::hash_type(uid);
+    uidTable_t &table = uidTable[log_id];
+    ssize_t index = table.find(-1, hash, uid);
+    if (index == -1) {
+        UidEntry initEntry(uid);
+        initEntry.add(size);
+        table.add(hash, initEntry);
     } else {
-        push_back(p);
+        UidEntry &entry = table.editEntryAt(index);
+        entry.add(size);
     }
-    p->add(size);
-}
-
-void UidStatistics::subtract(unsigned short size, pid_t pid) {
-    mSizes -= size;
-    --mElements;
-
-    PidStatisticsCollection::iterator it;
-    for (it = begin(); it != end(); ++it) {
-        PidStatistics *p = *it;
-        if (pid == p->getPid()) {
-            if (p->subtract(size)) {
-                size_t szsTotal = p->sizesTotal();
-                size_t elsTotal = p->elementsTotal();
-                delete p;
-                erase(it);
-                it = end();
-                --it;
-                if (it == end()) {
-                    p = new PidStatistics(p->gone);
-                    push_back(p);
-                } else {
-                    p = *it;
-                    if (p->getPid() != p->gone) {
-                        p = new PidStatistics(p->gone);
-                        push_back(p);
-                    }
-                }
-                p->addTotal(szsTotal, elsTotal);
-            }
-            return;
-        }
-    }
-}
-
-void UidStatistics::sort() {
-    for (bool pass = true; pass;) {
-        pass = false;
-        PidStatisticsCollection::iterator it = begin();
-        if (it != end()) {
-            PidStatisticsCollection::iterator lt = it;
-            PidStatistics *l = (*lt);
-            while (++it != end()) {
-                PidStatistics *n = (*it);
-                if ((n->getPid() != n->gone) && (n->sizes() > l->sizes())) {
-                    pass = true;
-                    erase(it);
-                    insert(lt, n);
-                    it = lt;
-                    n = l;
-                }
-                lt = it;
-                l = n;
-            }
-        }
-    }
-}
 
-size_t UidStatistics::sizes(pid_t pid) {
-    if (pid == pid_all) {
-        return sizes();
-    }
-
-    PidStatisticsCollection::iterator it;
-    for (it = begin(); it != end(); ++it) {
-        PidStatistics *p = *it;
-        if (pid == p->getPid()) {
-            return p->sizes();
-        }
-    }
-    return 0;
+    mSizesTotal[log_id] += size;
+    ++mElementsTotal[log_id];
 }
 
-size_t UidStatistics::elements(pid_t pid) {
-    if (pid == pid_all) {
-        return elements();
-    }
-
-    PidStatisticsCollection::iterator it;
-    for (it = begin(); it != end(); ++it) {
-        PidStatistics *p = *it;
-        if (pid == p->getPid()) {
-            return p->elements();
-        }
-    }
-    return 0;
-}
-
-size_t UidStatistics::sizesTotal(pid_t pid) {
-    size_t sizes = 0;
-    PidStatisticsCollection::iterator it;
-    for (it = begin(); it != end(); ++it) {
-        PidStatistics *p = *it;
-        if ((pid == pid_all) || (pid == p->getPid())) {
-            sizes += p->sizesTotal();
-        }
-    }
-    return sizes;
-}
+void LogStatistics::subtract(LogBufferElement *e) {
+    log_id_t log_id = e->getLogId();
+    unsigned short size = e->getMsgLen();
+    mSizes[log_id] -= size;
+    --mElements[log_id];
 
-size_t UidStatistics::elementsTotal(pid_t pid) {
-    size_t elements = 0;
-    PidStatisticsCollection::iterator it;
-    for (it = begin(); it != end(); ++it) {
-        PidStatistics *p = *it;
-        if ((pid == pid_all) || (pid == p->getPid())) {
-            elements += p->elementsTotal();
+    uid_t uid = e->getUid();
+    android::hash_t hash = android::hash_type(uid);
+    uidTable_t &table = uidTable[log_id];
+    ssize_t index = table.find(-1, hash, uid);
+    if (index != -1) {
+        UidEntry &entry = table.editEntryAt(index);
+        if (entry.subtract(size)) {
+            table.removeAt(index);
         }
     }
-    return elements;
-}
-
-LidStatistics::LidStatistics() {
-    Uids.clear();
 }
 
-LidStatistics::~LidStatistics() {
-    UidStatisticsCollection::iterator it;
-    for (it = begin(); it != end();) {
-        delete (*it);
-        it = Uids.erase(it);
+// caller must own and delete UidEntry array
+const UidEntry **LogStatistics::sort(size_t n, log_id id) {
+    if (!n) {
+        return NULL;
     }
-}
-
-void LidStatistics::add(unsigned short size, uid_t uid, pid_t pid) {
-    UidStatistics *u;
-    UidStatisticsCollection::iterator it;
-    UidStatisticsCollection::iterator last;
 
-    if (uid == (uid_t) -1) { // init
-        uid = (uid_t) AID_ROOT;
-    }
+    const UidEntry **retval = new const UidEntry* [n];
+    memset(retval, 0, sizeof(*retval) * n);
 
-    for (last = it = begin(); it != end(); last = it, ++it) {
-        u = *it;
-        if (uid == u->getUid()) {
-            u->add(size, pid);
-            if ((last != it) && ((*last)->sizesTotal() < u->sizesTotal())) {
-                Uids.erase(it);
-                Uids.insert(last, u);
-            }
-            return;
-        }
-    }
-    u = new UidStatistics(uid);
-    if ((last != it) && ((*last)->sizesTotal() < (size_t) size)) {
-        Uids.insert(last, u);
-    } else {
-        Uids.push_back(u);
-    }
-    u->add(size, pid);
-}
-
-void LidStatistics::subtract(unsigned short size, uid_t uid, pid_t pid) {
-    if (uid == (uid_t) -1) { // init
-        uid = (uid_t) AID_ROOT;
-    }
-
-    UidStatisticsCollection::iterator it;
-    for (it = begin(); it != end(); ++it) {
-        UidStatistics *u = *it;
-        if (uid == u->getUid()) {
-            u->subtract(size, pid);
-            return;
-        }
-    }
-}
-
-void LidStatistics::sort() {
-    for (bool pass = true; pass;) {
-        pass = false;
-        UidStatisticsCollection::iterator it = begin();
-        if (it != end()) {
-            UidStatisticsCollection::iterator lt = it;
-            UidStatistics *l = (*lt);
-            while (++it != end()) {
-                UidStatistics *n = (*it);
-                if (n->sizes() > l->sizes()) {
-                    pass = true;
-                    Uids.erase(it);
-                    Uids.insert(lt, n);
-                    it = lt;
-                    n = l;
-                }
-                lt = it;
-                l = n;
+    uidTable_t &table = uidTable[id];
+    ssize_t index = -1;
+    while ((index = table.next(index)) >= 0) {
+        const UidEntry &entry = table.entryAt(index);
+        size_t s = entry.getSizes();
+        ssize_t i = n - 1;
+        while ((!retval[i] || (s > retval[i]->getSizes())) && (--i >= 0));
+        if (++i < (ssize_t)n) {
+            size_t b = n - i - 1;
+            if (b) {
+                memmove(&retval[i+1], &retval[i], b * sizeof(retval[0]));
             }
+            retval[i] = &entry;
         }
     }
+    return retval;
 }
 
-size_t LidStatistics::sizes(uid_t uid, pid_t pid) {
-    size_t sizes = 0;
-    UidStatisticsCollection::iterator it;
-    for (it = begin(); it != end(); ++it) {
-        UidStatistics *u = *it;
-        if ((uid == uid_all) || (uid == u->getUid())) {
-            sizes += u->sizes(pid);
-        }
+// caller must own and free character string
+char *LogStatistics::uidToName(uid_t uid) {
+    // Local hard coded favourites
+    if (uid == AID_LOGD) {
+        return strdup("auditd");
     }
-    return sizes;
-}
 
-size_t LidStatistics::elements(uid_t uid, pid_t pid) {
-    size_t elements = 0;
-    UidStatisticsCollection::iterator it;
-    for (it = begin(); it != end(); ++it) {
-        UidStatistics *u = *it;
-        if ((uid == uid_all) || (uid == u->getUid())) {
-            elements += u->elements(pid);
-        }
-    }
-    return elements;
-}
+    // Android hard coded
+    const struct android_id_info *info = android_ids;
 
-size_t LidStatistics::sizesTotal(uid_t uid, pid_t pid) {
-    size_t sizes = 0;
-    UidStatisticsCollection::iterator it;
-    for (it = begin(); it != end(); ++it) {
-        UidStatistics *u = *it;
-        if ((uid == uid_all) || (uid == u->getUid())) {
-            sizes += u->sizesTotal(pid);
+    for (size_t i = 0; i < android_id_count; ++i) {
+        if (info->aid == uid) {
+            return strdup(info->name);
         }
+        ++info;
     }
-    return sizes;
-}
-
-size_t LidStatistics::elementsTotal(uid_t uid, pid_t pid) {
-    size_t elements = 0;
-    UidStatisticsCollection::iterator it;
-    for (it = begin(); it != end(); ++it) {
-        UidStatistics *u = *it;
-        if ((uid == uid_all) || (uid == u->getUid())) {
-            elements += u->elementsTotal(pid);
-        }
-    }
-    return elements;
-}
-
-LogStatistics::LogStatistics()
-        : mStatistics(false)
-        , start(CLOCK_MONOTONIC) {
-    log_id_for_each(i) {
-        mSizes[i] = 0;
-        mElements[i] = 0;
-    }
-}
-
-void LogStatistics::add(unsigned short size,
-                        log_id_t log_id, uid_t uid, pid_t pid) {
-    mSizes[log_id] += size;
-    ++mElements[log_id];
-    if (!mStatistics) {
-        return;
-    }
-    id(log_id).add(size, uid, pid);
-}
-
-void LogStatistics::subtract(unsigned short size,
-                             log_id_t log_id, uid_t uid, pid_t pid) {
-    mSizes[log_id] -= size;
-    --mElements[log_id];
-    if (!mStatistics) {
-        return;
-    }
-    id(log_id).subtract(size, uid, pid);
-}
-
-size_t LogStatistics::sizes(log_id_t log_id, uid_t uid, pid_t pid) {
-    if (log_id != log_id_all) {
-        return id(log_id).sizes(uid, pid);
-    }
-    size_t sizes = 0;
-    log_id_for_each(i) {
-        sizes += id(i).sizes(uid, pid);
-    }
-    return sizes;
-}
 
-size_t LogStatistics::elements(log_id_t log_id, uid_t uid, pid_t pid) {
-    if (log_id != log_id_all) {
-        return id(log_id).elements(uid, pid);
-    }
-    size_t elements = 0;
-    log_id_for_each(i) {
-        elements += id(i).elements(uid, pid);
-    }
-    return elements;
+    // No one
+    return NULL;
 }
 
-size_t LogStatistics::sizesTotal(log_id_t log_id, uid_t uid, pid_t pid) {
-    if (log_id != log_id_all) {
-        return id(log_id).sizesTotal(uid, pid);
-    }
-    size_t sizes = 0;
-    log_id_for_each(i) {
-        sizes += id(i).sizesTotal(uid, pid);
-    }
-    return sizes;
-}
+static void format_line(android::String8 &output,
+        android::String8 &name, android::String8 &size) {
+    static const size_t total_len = 70;
 
-size_t LogStatistics::elementsTotal(log_id_t log_id, uid_t uid, pid_t pid) {
-    if (log_id != log_id_all) {
-        return id(log_id).elementsTotal(uid, pid);
-    }
-    size_t elements = 0;
-    log_id_for_each(i) {
-        elements += id(i).elementsTotal(uid, pid);
-    }
-    return elements;
+    output.appendFormat("%s%*s\n", name.string(),
+        (int)std::max(total_len - name.length() - 1, size.length() + 1)
+        size.string());
 }
 
-void LogStatistics::format(char **buf,
-                           uid_t uid, unsigned int logMask, log_time oldest) {
-    static const unsigned short spaces_current = 13;
+void LogStatistics::format(char **buf, uid_t uid, unsigned int logMask) {
     static const unsigned short spaces_total = 19;
 
     if (*buf) {
@@ -476,368 +166,142 @@ void LogStatistics::format(char **buf,
         *buf = NULL;
     }
 
-    android::String8 string("        span -> size/num");
+    // Report on total logging, current and for all time
+
+    android::String8 output("size/num");
     size_t oldLength;
-    short spaces = 2;
+    short spaces = 1;
 
-    log_id_for_each(i) {
-        if (!(logMask & (1 << i))) {
+    log_id_for_each(id) {
+        if (!(logMask & (1 << id))) {
             continue;
         }
-        oldLength = string.length();
+        oldLength = output.length();
         if (spaces < 0) {
             spaces = 0;
         }
-        string.appendFormat("%*s%s", spaces, "", android_log_id_to_name(i));
-        spaces += spaces_total + oldLength - string.length();
+        output.appendFormat("%*s%s", spaces, "", android_log_id_to_name(id));
+        spaces += spaces_total + oldLength - output.length();
+    }
 
-        LidStatistics &l = id(i);
-        l.sort();
+    spaces = 4;
+    output.appendFormat("\nTotal");
 
-        UidStatisticsCollection::iterator iu;
-        for (iu = l.begin(); iu != l.end(); ++iu) {
-            (*iu)->sort();
+    log_id_for_each(id) {
+        if (!(logMask & (1 << id))) {
+            continue;
         }
-    }
-
-    spaces = 1;
-    log_time t(CLOCK_MONOTONIC);
-    unsigned long long d;
-    if (mStatistics) {
-        d = t.nsec() - start.nsec();
-        string.appendFormat("\nTotal%4llu:%02llu:%02llu.%09llu",
-                  d / NS_PER_SEC / 60 / 60, (d / NS_PER_SEC / 60) % 60,
-                  (d / NS_PER_SEC) % 60, d % NS_PER_SEC);
-
-        log_id_for_each(i) {
-            if (!(logMask & (1 << i))) {
-                continue;
-            }
-            oldLength = string.length();
-            if (spaces < 0) {
-                spaces = 0;
-            }
-            string.appendFormat("%*s%zu/%zu", spaces, "",
-                                sizesTotal(i), elementsTotal(i));
-            spaces += spaces_total + oldLength - string.length();
+        oldLength = output.length();
+        if (spaces < 0) {
+            spaces = 0;
         }
-        spaces = 1;
+        output.appendFormat("%*s%zu/%zu", spaces, "",
+                            sizesTotal(id), elementsTotal(id));
+        spaces += spaces_total + oldLength - output.length();
     }
 
-    d = t.nsec() - oldest.nsec();
-    string.appendFormat("\nNow%6llu:%02llu:%02llu.%09llu",
-                  d / NS_PER_SEC / 60 / 60, (d / NS_PER_SEC / 60) % 60,
-                  (d / NS_PER_SEC) % 60, d % NS_PER_SEC);
+    spaces = 6;
+    output.appendFormat("\nNow");
 
-    log_id_for_each(i) {
-        if (!(logMask & (1 << i))) {
+    log_id_for_each(id) {
+        if (!(logMask & (1 << id))) {
             continue;
         }
 
-        size_t els = elements(i);
+        size_t els = elements(id);
         if (els) {
-            oldLength = string.length();
+            oldLength = output.length();
             if (spaces < 0) {
                 spaces = 0;
             }
-            string.appendFormat("%*s%zu/%zu", spaces, "", sizes(i), els);
-            spaces -= string.length() - oldLength;
+            output.appendFormat("%*s%zu/%zu", spaces, "", sizes(id), els);
+            spaces -= output.length() - oldLength;
         }
         spaces += spaces_total;
     }
 
-    // Construct list of worst spammers by Pid
-    static const unsigned char num_spammers = 10;
-    bool header = false;
+    // Report on Chattiest
 
-    log_id_for_each(i) {
-        if (!(logMask & (1 << i))) {
+    // Chattiest by application (UID)
+    log_id_for_each(id) {
+        if (!(logMask & (1 << id))) {
             continue;
         }
 
-        PidStatisticsCollection pids;
-        pids.clear();
-
-        LidStatistics &l = id(i);
-        UidStatisticsCollection::iterator iu;
-        for (iu = l.begin(); iu != l.end(); ++iu) {
-            UidStatistics &u = *(*iu);
-            PidStatisticsCollection::iterator ip;
-            for (ip = u.begin(); ip != u.end(); ++ip) {
-                PidStatistics *p = (*ip);
-                if (p->getPid() == p->gone) {
-                    break;
-                }
-
-                size_t mySizes = p->sizes();
-
-                PidStatisticsCollection::iterator q;
-                unsigned char num = 0;
-                for (q = pids.begin(); q != pids.end(); ++q) {
-                    if (mySizes > (*q)->sizes()) {
-                        pids.insert(q, p);
-                        break;
-                    }
-                    // do we need to traverse deeper in the list?
-                    if (++num > num_spammers) {
-                        break;
-                    }
-                }
-                if (q == pids.end()) {
-                   pids.push_back(p);
-                }
-            }
-        }
+        static const size_t maximum_sorted_entries = 32;
+        const UidEntry **sorted = sort(maximum_sorted_entries, id);
 
-        size_t threshold = sizes(i);
-        if (threshold < 65536) {
-            threshold = 65536;
+        if (!sorted) {
+            continue;
         }
-        threshold /= 100;
-
-        PidStatisticsCollection::iterator pt = pids.begin();
 
-        for(int line = 0;
-                (pt != pids.end()) && (line < num_spammers);
-                ++line, pt = pids.erase(pt)) {
-            PidStatistics *p = *pt;
+        bool print = false;
+        for(size_t index = 0; index < maximum_sorted_entries; ++index) {
+            const UidEntry *entry = sorted[index];
 
-            size_t sizes = p->sizes();
-            if (sizes < threshold) {
+            if (!entry) {
                 break;
             }
 
-            char *name = p->getName();
-            pid_t pid = p->getPid();
-            if (!name || !*name) {
-                name = pidToName(pid);
-                if (name) {
-                    if (*name) {
-                        p->setName(name);
-                    } else {
-                        free(name);
-                        name = NULL;
-                    }
-                }
-            }
-
-            if (!header) {
-                string.appendFormat("\n\nChattiest clients:\n"
-                                    "log id %-*s PID[?] name",
-                                    spaces_total, "size/total");
-                header = true;
-            }
-
-            size_t sizesTotal = p->sizesTotal();
-
-            android::String8 sz("");
-            if (sizes == sizesTotal) {
-                sz.appendFormat("%zu", sizes);
-            } else {
-                sz.appendFormat("%zu/%zu", sizes, sizesTotal);
-            }
-
-            android::String8 pd("");
-            pd.appendFormat("%u%c", pid, p->pidGone() ? '?' : ' ');
-
-            string.appendFormat("\n%-7s%-*s %-7s%s",
-                                line ? "" : android_log_id_to_name(i),
-                                spaces_total, sz.string(), pd.string(),
-                                name ? name : "");
-        }
-
-        pids.clear();
-    }
-
-    log_id_for_each(i) {
-        if (!(logMask & (1 << i))) {
-            continue;
-        }
-
-        header = false;
-        bool first = true;
-
-        UidStatisticsCollection::iterator ut;
-        for(ut = id(i).begin(); ut != id(i).end(); ++ut) {
-            UidStatistics *up = *ut;
-            if ((uid != AID_ROOT) && (uid != up->getUid())) {
-                continue;
+            size_t sizes = entry->getSizes();
+            if (sizes < (65536/100)) {
+                break;
             }
 
-            PidStatisticsCollection::iterator pt = up->begin();
-            if (pt == up->end()) {
+            uid_t u = entry->getKey();
+            if ((uid != AID_ROOT) && (u != uid)) {
                 continue;
             }
 
-            android::String8 intermediate;
-
-            if (!header) {
-                // header below tuned to match spaces_total and spaces_current
-                spaces = 0;
-                intermediate = string.format("%s: UID/PID Total size/num",
-                                             android_log_id_to_name(i));
-                string.appendFormat("\n\n%-31sNow          "
-                                         "UID/PID[?]  Total              Now",
-                                    intermediate.string());
-                intermediate.clear();
-                header = true;
-            }
-
-            bool oneline = ++pt == up->end();
-            --pt;
-
-            if (!oneline) {
-                first = true;
-            } else if (!first && (spaces > 0)) {
-                string.appendFormat("%*s", spaces, "");
-            }
-            spaces = 0;
-
-            uid_t u = up->getUid();
-            PidStatistics *pp = *pt;
-            pid_t p = pp->getPid();
-
-            if (!oneline) {
-                intermediate = string.format("%d", u);
-            } else if (p == PidStatistics::gone) {
-                intermediate = string.format("%d/?", u);
-            } else if (pp->pidGone()) {
-                intermediate = string.format("%d/%d?", u, p);
-            } else {
-                intermediate = string.format("%d/%d", u, p);
-            }
-            string.appendFormat(first ? "\n%-12s" : "%-12s",
-                                intermediate.string());
-            intermediate.clear();
-
-            size_t elsTotal = up->elementsTotal();
-            oldLength = string.length();
-            string.appendFormat("%zu/%zu", up->sizesTotal(), elsTotal);
-            spaces += spaces_total + oldLength - string.length();
-
-            size_t els = up->elements();
-            if (els == elsTotal) {
-                if (spaces < 0) {
-                    spaces = 0;
-                }
-                string.appendFormat("%*s=", spaces, "");
-                spaces = -1;
-            } else if (els) {
-                oldLength = string.length();
-                if (spaces < 0) {
-                    spaces = 0;
+            if (!print) {
+                if (uid == AID_ROOT) {
+                    output.appendFormat(
+                        "\n\nChattiest UIDs in %s:\n",
+                        android_log_id_to_name(id));
+                    android::String8 name("UID");
+                    android::String8 size("Size");
+                    format_line(output, name, size);
+                } else {
+                    output.appendFormat(
+                        "\n\nLogging for your UID in %s:\n",
+                        android_log_id_to_name(id));
                 }
-                string.appendFormat("%*s%zu/%zu", spaces, "", up->sizes(), els);
-                spaces -= string.length() - oldLength;
+                print = true;
             }
-            spaces += spaces_current;
-
-            first = !first;
 
-            if (oneline) {
-                continue;
+            android::String8 name("");
+            name.appendFormat("%u", u);
+            char *n = uidToName(u);
+            if (n) {
+                name.appendFormat("%*s%s", (int)std::max(6 - name.length(), (size_t)1), "", n);
+                free(n);
             }
 
-            size_t gone_szs = 0;
-            size_t gone_els = 0;
-
-            for(; pt != up->end(); ++pt) {
-                pp = *pt;
-                p = pp->getPid();
-
-                // If a PID no longer has any current logs, and is not
-                // active anymore, skip & report totals for gone.
-                elsTotal = pp->elementsTotal();
-                size_t szsTotal = pp->sizesTotal();
-                if (p == pp->gone) {
-                    gone_szs += szsTotal;
-                    gone_els += elsTotal;
-                    continue;
-                }
-                els = pp->elements();
-                bool gone = pp->pidGone();
-                if (gone && (els == 0)) {
-                    // ToDo: garbage collection: move this statistical bucket
-                    //       from its current UID/PID to UID/? (races and
-                    //       wrap around are our achilles heel). Below is
-                    //       merely lipservice to catch PIDs that were still
-                    //       around when the stats were pruned to zero.
-                    gone_szs += szsTotal;
-                    gone_els += elsTotal;
-                    continue;
-                }
-
-                if (!first && (spaces > 0)) {
-                    string.appendFormat("%*s", spaces, "");
-                }
-                spaces = 0;
-
-                intermediate = string.format(gone ? "%d/%d?" : "%d/%d", u, p);
-                string.appendFormat(first ? "\n%-12s" : "%-12s",
-                                    intermediate.string());
-                intermediate.clear();
-
-                oldLength = string.length();
-                string.appendFormat("%zu/%zu", szsTotal, elsTotal);
-                spaces += spaces_total + oldLength - string.length();
-
-                if (els == elsTotal) {
-                    if (spaces < 0) {
-                        spaces = 0;
-                    }
-                    string.appendFormat("%*s=", spaces, "");
-                    spaces = -1;
-                } else if (els) {
-                    oldLength = string.length();
-                    if (spaces < 0) {
-                        spaces = 0;
-                    }
-                    string.appendFormat("%*s%zu/%zu", spaces, "",
-                                        pp->sizes(), els);
-                    spaces -= string.length() - oldLength;
-                }
-                spaces += spaces_current;
+            android::String8 size("");
+            size.appendFormat("%zu", sizes);
 
-                first = !first;
-            }
-
-            if (gone_els) {
-                if (!first && (spaces > 0)) {
-                    string.appendFormat("%*s", spaces, "");
-                }
-
-                intermediate = string.format("%d/?", u);
-                string.appendFormat(first ? "\n%-12s" : "%-12s",
-                                    intermediate.string());
-                intermediate.clear();
-
-                spaces = spaces_total + spaces_current;
-
-                oldLength = string.length();
-                string.appendFormat("%zu/%zu", gone_szs, gone_els);
-                spaces -= string.length() - oldLength;
-
-                first = !first;
-            }
+            format_line(output, name, size);
         }
+
+        delete [] sorted;
     }
 
-    *buf = strdup(string.string());
+    *buf = strdup(output.string());
 }
 
 uid_t LogStatistics::pidToUid(pid_t pid) {
-    log_id_for_each(i) {
-        LidStatistics &l = id(i);
-        UidStatisticsCollection::iterator iu;
-        for (iu = l.begin(); iu != l.end(); ++iu) {
-            UidStatistics &u = *(*iu);
-            PidStatisticsCollection::iterator ip;
-            for (ip = u.begin(); ip != u.end(); ++ip) {
-                if ((*ip)->getPid() == pid) {
-                    return u.getUid();
-                }
+    char buffer[512];
+    snprintf(buffer, sizeof(buffer), "/proc/%u/status", pid);
+    FILE *fp = fopen(buffer, "r");
+    if (fp) {
+        while (fgets(buffer, sizeof(buffer), fp)) {
+            int uid;
+            if (sscanf(buffer, "Groups: %d", &uid) == 1) {
+                fclose(fp);
+                return uid;
             }
         }
+        fclose(fp);
     }
     return getuid(); // associate this with the logger
 }