LogStatistics.h revision 6a06694a610d103afdf424b0bb69dc8f7f2b8e5a 
1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef _LOGD_LOG_STATISTICS_H__
18#define _LOGD_LOG_STATISTICS_H__
19
20#include <memory>
21#include <stdlib.h>
22#include <sys/types.h>
23
24#include <algorithm> // std::max
25#include <string>    // std::string
26#include <unordered_map>
27
28#include <android-base/stringprintf.h>
29#include <log/log.h>
30#include <private/android_filesystem_config.h>
31
32#include "LogBufferElement.h"
33#include "LogUtils.h"
34
35#define log_id_for_each(i) \
36    for (log_id_t i = LOG_ID_MIN; (i) < LOG_ID_MAX; (i) = (log_id_t) ((i) + 1))
37
38class LogStatistics;
39
40template <typename TKey, typename TEntry>
41class LogHashtable {
42
43    std::unordered_map<TKey, TEntry> map;
44
45public:
46
47    typedef typename std::unordered_map<TKey, TEntry>::iterator iterator;
48    typedef typename std::unordered_map<TKey, TEntry>::const_iterator const_iterator;
49
50    std::unique_ptr<const TEntry *[]> sort(uid_t uid, pid_t pid,
51                                           size_t len) const {
52        if (!len) {
53            std::unique_ptr<const TEntry *[]> sorted(NULL);
54            return sorted;
55        }
56
57        const TEntry **retval = new const TEntry* [len];
58        memset(retval, 0, sizeof(*retval) * len);
59
60        for(const_iterator it = map.begin(); it != map.end(); ++it) {
61            const TEntry &entry = it->second;
62
63            if ((uid != AID_ROOT) && (uid != entry.getUid())) {
64                continue;
65            }
66            if (pid && entry.getPid() && (pid != entry.getPid())) {
67                continue;
68            }
69
70            size_t sizes = entry.getSizes();
71            ssize_t index = len - 1;
72            while ((!retval[index] || (sizes > retval[index]->getSizes()))
73                    && (--index >= 0))
74                ;
75            if (++index < (ssize_t)len) {
76                size_t num = len - index - 1;
77                if (num) {
78                    memmove(&retval[index + 1], &retval[index],
79                            num * sizeof(retval[0]));
80                }
81                retval[index] = &entry;
82            }
83        }
84        std::unique_ptr<const TEntry *[]> sorted(retval);
85        return sorted;
86    }
87
88    inline iterator add(TKey key, LogBufferElement *element) {
89        iterator it = map.find(key);
90        if (it == map.end()) {
91            it = map.insert(std::make_pair(key, TEntry(element))).first;
92        } else {
93            it->second.add(element);
94        }
95        return it;
96    }
97
98    inline iterator add(TKey key) {
99        iterator it = map.find(key);
100        if (it == map.end()) {
101            it = map.insert(std::make_pair(key, TEntry(key))).first;
102        } else {
103            it->second.add(key);
104        }
105        return it;
106    }
107
108    void subtract(TKey key, LogBufferElement *element) {
109        iterator it = map.find(key);
110        if ((it != map.end()) && it->second.subtract(element)) {
111            map.erase(it);
112        }
113    }
114
115    inline void drop(TKey key, LogBufferElement *element) {
116        iterator it = map.find(key);
117        if (it != map.end()) {
118            it->second.drop(element);
119        }
120    }
121
122    inline iterator begin() { return map.begin(); }
123    inline const_iterator begin() const { return map.begin(); }
124    inline iterator end() { return map.end(); }
125    inline const_iterator end() const { return map.end(); }
126
127    std::string format(
128            const LogStatistics &stat,
129            uid_t uid,
130            pid_t pid,
131            const std::string &name = std::string(""),
132            log_id_t id = LOG_ID_MAX) const {
133        static const size_t maximum_sorted_entries = 32;
134        std::string output;
135        std::unique_ptr<const TEntry *[]> sorted = sort(uid, pid,
136                                                        maximum_sorted_entries);
137        if (!sorted.get()) {
138            return output;
139        }
140        bool headerPrinted = false;
141        for (size_t index = 0; index < maximum_sorted_entries; ++index) {
142            const TEntry *entry = sorted[index];
143            if (!entry) {
144                break;
145            }
146            if (entry->getSizes() <= (sorted[0]->getSizes() / 100)) {
147                break;
148            }
149            if (!headerPrinted) {
150                output += "\n\n";
151                output += entry->formatHeader(name, id);
152                headerPrinted = true;
153            }
154            output += entry->format(stat, id);
155        }
156        return output;
157    }
158};
159
160namespace EntryBaseConstants {
161    static constexpr size_t pruned_len = 14;
162    static constexpr size_t total_len = 80;
163}
164
165struct EntryBase {
166    size_t size;
167
168    EntryBase():size(0) { }
169    EntryBase(LogBufferElement *element):size(element->getMsgLen()) { }
170
171    size_t getSizes() const { return size; }
172
173    inline void add(LogBufferElement *element) { size += element->getMsgLen(); }
174    inline bool subtract(LogBufferElement *element) {
175        size -= element->getMsgLen();
176        return !size;
177    }
178
179    static std::string formatLine(
180            const std::string &name,
181            const std::string &size,
182            const std::string &pruned) {
183        ssize_t drop_len = std::max(pruned.length() + 1,
184                                    EntryBaseConstants::pruned_len);
185        ssize_t size_len = std::max(size.length() + 1,
186                                    EntryBaseConstants::total_len
187                                        - name.length() - drop_len - 1);
188
189        if (pruned.length()) {
190            return android::base::StringPrintf("%s%*s%*s\n", name.c_str(),
191                                               (int)size_len, size.c_str(),
192                                               (int)drop_len, pruned.c_str());
193        } else {
194            return android::base::StringPrintf("%s%*s\n", name.c_str(),
195                                               (int)size_len, size.c_str());
196        }
197    }
198};
199
200struct EntryBaseDropped : public EntryBase {
201    size_t dropped;
202
203    EntryBaseDropped():dropped(0) { }
204    EntryBaseDropped(LogBufferElement *element):
205            EntryBase(element),
206            dropped(element->getDropped()) {
207    }
208
209    size_t getDropped() const { return dropped; }
210
211    inline void add(LogBufferElement *element) {
212        dropped += element->getDropped();
213        EntryBase::add(element);
214    }
215    inline bool subtract(LogBufferElement *element) {
216        dropped -= element->getDropped();
217        return EntryBase::subtract(element) && !dropped;
218    }
219    inline void drop(LogBufferElement *element) {
220        dropped += 1;
221        EntryBase::subtract(element);
222    }
223};
224
225struct UidEntry : public EntryBaseDropped {
226    const uid_t uid;
227    pid_t pid;
228
229    UidEntry(LogBufferElement *element):
230            EntryBaseDropped(element),
231            uid(element->getUid()),
232            pid(element->getPid()) {
233    }
234
235    inline const uid_t&getKey() const { return uid; }
236    inline const uid_t&getUid() const { return getKey(); }
237    inline const pid_t&getPid() const { return pid; }
238
239    inline void add(LogBufferElement *element) {
240        if (pid != element->getPid()) {
241            pid = -1;
242        }
243        EntryBase::add(element);
244    }
245
246    std::string formatHeader(const std::string &name, log_id_t id) const;
247    std::string format(const LogStatistics &stat, log_id_t id) const;
248};
249
250namespace android {
251uid_t pidToUid(pid_t pid);
252}
253
254struct PidEntry : public EntryBaseDropped {
255    const pid_t pid;
256    uid_t uid;
257    char *name;
258
259    PidEntry(pid_t pid):
260            EntryBaseDropped(),
261            pid(pid),
262            uid(android::pidToUid(pid)),
263            name(android::pidToName(pid)) {
264    }
265    PidEntry(LogBufferElement *element):
266            EntryBaseDropped(element),
267            pid(element->getPid()),
268            uid(element->getUid()),
269            name(android::pidToName(pid)) {
270    }
271    PidEntry(const PidEntry &element):
272            EntryBaseDropped(element),
273            pid(element.pid),
274            uid(element.uid),
275            name(element.name ? strdup(element.name) : NULL) {
276    }
277    ~PidEntry() { free(name); }
278
279    const pid_t&getKey() const { return pid; }
280    const pid_t&getPid() const { return getKey(); }
281    const uid_t&getUid() const { return uid; }
282    const char*getName() const { return name; }
283
284    inline void add(pid_t newPid) {
285        if (name && !fast<strncmp>(name, "zygote", 6)) {
286            free(name);
287            name = NULL;
288        }
289        if (!name) {
290            name = android::pidToName(newPid);
291        }
292    }
293
294    inline void add(LogBufferElement *element) {
295        uid_t incomingUid = element->getUid();
296        if (getUid() != incomingUid) {
297            uid = incomingUid;
298            free(name);
299            name = android::pidToName(element->getPid());
300        } else {
301            add(element->getPid());
302        }
303        EntryBaseDropped::add(element);
304    }
305
306    std::string formatHeader(const std::string &name, log_id_t id) const;
307    std::string format(const LogStatistics &stat, log_id_t id) const;
308};
309
310struct TidEntry : public EntryBaseDropped {
311    const pid_t tid;
312    pid_t pid;
313    uid_t uid;
314    char *name;
315
316    TidEntry(pid_t tid, pid_t pid):
317            EntryBaseDropped(),
318            tid(tid),
319            pid(pid),
320            uid(android::pidToUid(tid)),
321            name(android::tidToName(tid)) {
322    }
323    TidEntry(LogBufferElement *element):
324            EntryBaseDropped(element),
325            tid(element->getTid()),
326            pid(element->getPid()),
327            uid(element->getUid()),
328            name(android::tidToName(tid)) {
329    }
330    TidEntry(const TidEntry &element):
331            EntryBaseDropped(element),
332            tid(element.tid),
333            pid(element.pid),
334            uid(element.uid),
335            name(element.name ? strdup(element.name) : NULL) {
336    }
337    ~TidEntry() { free(name); }
338
339    const pid_t&getKey() const { return tid; }
340    const pid_t&getTid() const { return getKey(); }
341    const pid_t&getPid() const { return pid; }
342    const uid_t&getUid() const { return uid; }
343    const char*getName() const { return name; }
344
345    inline void add(pid_t incomingTid) {
346        if (name && !fast<strncmp>(name, "zygote", 6)) {
347            free(name);
348            name = NULL;
349        }
350        if (!name) {
351            name = android::tidToName(incomingTid);
352        }
353    }
354
355    inline void add(LogBufferElement *element) {
356        uid_t incomingUid = element->getUid();
357        pid_t incomingPid = element->getPid();
358        if ((getUid() != incomingUid) || (getPid() != incomingPid)) {
359            uid = incomingUid;
360            pid = incomingPid;
361            free(name);
362            name = android::tidToName(element->getTid());
363        } else {
364            add(element->getTid());
365        }
366        EntryBaseDropped::add(element);
367    }
368
369    std::string formatHeader(const std::string &name, log_id_t id) const;
370    std::string format(const LogStatistics &stat, log_id_t id) const;
371};
372
373struct TagEntry : public EntryBaseDropped {
374    const uint32_t tag;
375    pid_t pid;
376    uid_t uid;
377
378    TagEntry(LogBufferElement *element):
379            EntryBaseDropped(element),
380            tag(element->getTag()),
381            pid(element->getPid()),
382            uid(element->getUid()) {
383    }
384
385    const uint32_t&getKey() const { return tag; }
386    const pid_t&getPid() const { return pid; }
387    const uid_t&getUid() const { return uid; }
388    const char*getName() const { return android::tagToName(tag); }
389
390    inline void add(LogBufferElement *element) {
391        if (uid != element->getUid()) {
392            uid = -1;
393        }
394        if (pid != element->getPid()) {
395            pid = -1;
396        }
397        EntryBase::add(element);
398    }
399
400    std::string formatHeader(const std::string &name, log_id_t id) const;
401    std::string format(const LogStatistics &stat, log_id_t id) const;
402};
403
404template <typename TEntry>
405class LogFindWorst {
406    std::unique_ptr<const TEntry *[]> sorted;
407
408public:
409
410    LogFindWorst(std::unique_ptr<const TEntry *[]> &&sorted) : sorted(std::move(sorted)) { }
411
412    void findWorst(int &worst,
413                    size_t &worst_sizes, size_t &second_worst_sizes,
414                    size_t threshold) {
415        if (sorted.get() && sorted[0] && sorted[1]) {
416            worst_sizes = sorted[0]->getSizes();
417            if ((worst_sizes > threshold)
418                // Allow time horizon to extend roughly tenfold, assume
419                // average entry length is 100 characters.
420                    && (worst_sizes > (10 * sorted[0]->getDropped()))) {
421                worst = sorted[0]->getKey();
422                second_worst_sizes = sorted[1]->getSizes();
423                if (second_worst_sizes < threshold) {
424                    second_worst_sizes = threshold;
425                }
426            }
427        }
428    }
429
430    void findWorst(int &worst,
431                    size_t worst_sizes, size_t &second_worst_sizes) {
432        if (sorted.get() && sorted[0] && sorted[1]) {
433            worst = sorted[0]->getKey();
434            second_worst_sizes = worst_sizes
435                               - sorted[0]->getSizes()
436                               + sorted[1]->getSizes();
437        }
438    }
439};
440
441// Log Statistics
442class LogStatistics {
443    friend UidEntry;
444
445    size_t mSizes[LOG_ID_MAX];
446    size_t mElements[LOG_ID_MAX];
447    size_t mDroppedElements[LOG_ID_MAX];
448    size_t mSizesTotal[LOG_ID_MAX];
449    size_t mElementsTotal[LOG_ID_MAX];
450    bool enable;
451
452    // uid to size list
453    typedef LogHashtable<uid_t, UidEntry> uidTable_t;
454    uidTable_t uidTable[LOG_ID_MAX];
455
456    // pid of system to size list
457    typedef LogHashtable<pid_t, PidEntry> pidSystemTable_t;
458    pidSystemTable_t pidSystemTable[LOG_ID_MAX];
459
460    // pid to uid list
461    typedef LogHashtable<pid_t, PidEntry> pidTable_t;
462    pidTable_t pidTable;
463
464    // tid to uid list
465    typedef LogHashtable<pid_t, TidEntry> tidTable_t;
466    tidTable_t tidTable;
467
468    // tag list
469    typedef LogHashtable<uint32_t, TagEntry> tagTable_t;
470    tagTable_t tagTable;
471
472    // security tag list
473    tagTable_t securityTagTable;
474
475public:
476    LogStatistics();
477
478    void enableStatistics() { enable = true; }
479
480    void add(LogBufferElement *entry);
481    void subtract(LogBufferElement *entry);
482    // entry->setDropped(1) must follow this call
483    void drop(LogBufferElement *entry);
484    // Correct for coalescing two entries referencing dropped content
485    void erase(LogBufferElement *element) {
486        log_id_t log_id = element->getLogId();
487        --mElements[log_id];
488        --mDroppedElements[log_id];
489    }
490
491    LogFindWorst<UidEntry> sort(uid_t uid, pid_t pid, size_t len, log_id id) {
492        return LogFindWorst<UidEntry>(uidTable[id].sort(uid, pid, len));
493    }
494    LogFindWorst<PidEntry> sortPids(uid_t uid, pid_t pid, size_t len, log_id id) {
495        return LogFindWorst<PidEntry>(pidSystemTable[id].sort(uid, pid, len));
496    }
497    LogFindWorst<TagEntry> sortTags(uid_t uid, pid_t pid, size_t len, log_id) {
498        return LogFindWorst<TagEntry>(tagTable.sort(uid, pid, len));
499    }
500
501    // fast track current value by id only
502    size_t sizes(log_id_t id) const { return mSizes[id]; }
503    size_t elements(log_id_t id) const { return mElements[id]; }
504    size_t realElements(log_id_t id) const {
505        return mElements[id] - mDroppedElements[id];
506    }
507    size_t sizesTotal(log_id_t id) const { return mSizesTotal[id]; }
508    size_t elementsTotal(log_id_t id) const { return mElementsTotal[id]; }
509
510    std::string format(uid_t uid, pid_t pid, unsigned int logMask) const;
511
512    // helper (must be locked directly or implicitly by mLogElementsLock)
513    const char *pidToName(pid_t pid) const;
514    uid_t pidToUid(pid_t pid);
515    const char *uidToName(uid_t uid) const;
516};
517
518#endif // _LOGD_LOG_STATISTICS_H__
519