LogStatistics.h revision ed777e9eece54bf899f1a77a83f8b702970de686 
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 <unordered_map>
25
26#include <log/log.h>
27
28#include "LogBufferElement.h"
29
30#define log_id_for_each(i) \
31    for (log_id_t i = LOG_ID_MIN; i < LOG_ID_MAX; i = (log_id_t) (i + 1))
32
33template <typename TKey, typename TEntry>
34class LogHashtable {
35
36    std::unordered_map<TKey, TEntry> map;
37
38public:
39
40    typedef typename std::unordered_map<TKey, TEntry>::iterator iterator;
41
42    std::unique_ptr<const TEntry *[]> sort(size_t n) {
43        if (!n) {
44            std::unique_ptr<const TEntry *[]> sorted(NULL);
45            return sorted;
46        }
47
48        const TEntry **retval = new const TEntry* [n];
49        memset(retval, 0, sizeof(*retval) * n);
50
51        for(iterator it = map.begin(); it != map.end(); ++it) {
52            const TEntry &entry = it->second;
53            size_t s = entry.getSizes();
54            ssize_t i = n - 1;
55            while ((!retval[i] || (s > retval[i]->getSizes())) && (--i >= 0))
56                ;
57            if (++i < (ssize_t)n) {
58                size_t b = n - i - 1;
59                if (b) {
60                    memmove(&retval[i+1], &retval[i], b * sizeof(retval[0]));
61                }
62                retval[i] = &entry;
63            }
64        }
65        std::unique_ptr<const TEntry *[]> sorted(retval);
66        return sorted;
67    }
68
69    // Iteration handler for the sort method output
70    static ssize_t next(ssize_t index, std::unique_ptr<const TEntry *[]> &sorted, size_t n) {
71        ++index;
72        if (!sorted.get() || (index < 0) || (n <= (size_t)index) || !sorted[index]
73         || (sorted[index]->getSizes() <= (sorted[0]->getSizes() / 100))) {
74            return -1;
75        }
76        return index;
77    }
78
79    inline iterator add(TKey key, LogBufferElement *e) {
80        iterator it = map.find(key);
81        if (it == map.end()) {
82            it = map.insert(std::make_pair(key, TEntry(e))).first;
83        } else {
84            it->second.add(e);
85        }
86        return it;
87    }
88
89    inline iterator add(TKey key) {
90        iterator it = map.find(key);
91        if (it == map.end()) {
92            it = map.insert(std::make_pair(key, TEntry(key))).first;
93        } else {
94            it->second.add(key);
95        }
96        return it;
97    }
98
99    void subtract(TKey key, LogBufferElement *e) {
100        iterator it = map.find(key);
101        if ((it != map.end()) && it->second.subtract(e)) {
102            map.erase(it);
103        }
104    }
105
106    inline void drop(TKey key, LogBufferElement *e) {
107        iterator it = map.find(key);
108        if (it != map.end()) {
109            it->second.drop(e);
110        }
111    }
112
113    inline iterator begin() { return map.begin(); }
114    inline iterator end() { return map.end(); }
115
116};
117
118struct EntryBase {
119    size_t size;
120
121    EntryBase():size(0) { }
122    EntryBase(LogBufferElement *e):size(e->getMsgLen()) { }
123
124    size_t getSizes() const { return size; }
125
126    inline void add(LogBufferElement *e) { size += e->getMsgLen(); }
127    inline bool subtract(LogBufferElement *e) { size -= e->getMsgLen(); return !size; }
128};
129
130struct EntryBaseDropped : public EntryBase {
131    size_t dropped;
132
133    EntryBaseDropped():dropped(0) { }
134    EntryBaseDropped(LogBufferElement *e):EntryBase(e),dropped(e->getDropped()){ }
135
136    size_t getDropped() const { return dropped; }
137
138    inline void add(LogBufferElement *e) {
139        dropped += e->getDropped();
140        EntryBase::add(e);
141    }
142    inline bool subtract(LogBufferElement *e) {
143        dropped -= e->getDropped();
144        return EntryBase::subtract(e) && !dropped;
145    }
146    inline void drop(LogBufferElement *e) {
147        dropped += 1;
148        EntryBase::subtract(e);
149    }
150};
151
152struct UidEntry : public EntryBaseDropped {
153    const uid_t uid;
154
155    UidEntry(LogBufferElement *e):EntryBaseDropped(e),uid(e->getUid()) { }
156
157    inline const uid_t&getKey() const { return uid; }
158};
159
160namespace android {
161uid_t pidToUid(pid_t pid);
162}
163
164struct PidEntry : public EntryBaseDropped {
165    const pid_t pid;
166    uid_t uid;
167    char *name;
168
169    PidEntry(pid_t p):
170        EntryBaseDropped(),
171        pid(p),
172        uid(android::pidToUid(p)),
173        name(android::pidToName(pid)) { }
174    PidEntry(LogBufferElement *e):
175        EntryBaseDropped(e),
176        pid(e->getPid()),
177        uid(e->getUid()),
178        name(android::pidToName(e->getPid())) { }
179    PidEntry(const PidEntry &c):
180        EntryBaseDropped(c),
181        pid(c.pid),
182        uid(c.uid),
183        name(c.name ? strdup(c.name) : NULL) { }
184    ~PidEntry() { free(name); }
185
186    const pid_t&getKey() const { return pid; }
187    const uid_t&getUid() const { return uid; }
188    const char*getName() const { return name; }
189
190    inline void add(pid_t p) {
191        if (name && !strncmp(name, "zygote", 6)) {
192            free(name);
193            name = NULL;
194        }
195        if (!name) {
196            char *n = android::pidToName(p);
197            if (n) {
198                name = n;
199            }
200        }
201    }
202
203    inline void add(LogBufferElement *e) {
204        uid_t u = e->getUid();
205        if (getUid() != u) {
206            uid = u;
207            free(name);
208            name = android::pidToName(e->getPid());
209        } else {
210            add(e->getPid());
211        }
212        EntryBaseDropped::add(e);
213    }
214};
215
216struct TidEntry : public EntryBaseDropped {
217    const pid_t tid;
218    uid_t uid;
219    char *name;
220
221    TidEntry(pid_t t):
222        EntryBaseDropped(),
223        tid(t),
224        uid(android::pidToUid(t)),
225        name(android::tidToName(tid)) { }
226    TidEntry(LogBufferElement *e):
227        EntryBaseDropped(e),
228        tid(e->getTid()),
229        uid(e->getUid()),
230        name(android::tidToName(e->getTid())) { }
231    TidEntry(const TidEntry &c):
232        EntryBaseDropped(c),
233        tid(c.tid),
234        uid(c.uid),
235        name(c.name ? strdup(c.name) : NULL) { }
236    ~TidEntry() { free(name); }
237
238    const pid_t&getKey() const { return tid; }
239    const uid_t&getUid() const { return uid; }
240    const char*getName() const { return name; }
241
242    inline void add(pid_t t) {
243        if (name && !strncmp(name, "zygote", 6)) {
244            free(name);
245            name = NULL;
246        }
247        if (!name) {
248            char *n = android::tidToName(t);
249            if (n) {
250                name = n;
251            }
252        }
253    }
254
255    inline void add(LogBufferElement *e) {
256        uid_t u = e->getUid();
257        if (getUid() != u) {
258            uid = u;
259            free(name);
260            name = android::tidToName(e->getTid());
261        } else {
262            add(e->getTid());
263        }
264        EntryBaseDropped::add(e);
265    }
266};
267
268struct TagEntry : public EntryBase {
269    const uint32_t tag;
270    uid_t uid;
271
272    TagEntry(LogBufferElement *e):
273        EntryBase(e),
274        tag(e->getTag()),
275        uid(e->getUid()) { }
276
277    const uint32_t&getKey() const { return tag; }
278    const uid_t&getUid() const { return uid; }
279    const char*getName() const { return android::tagToName(tag); }
280
281    inline void add(LogBufferElement *e) {
282        uid_t u = e->getUid();
283        if (uid != u) {
284            uid = -1;
285        }
286        EntryBase::add(e);
287    }
288};
289
290// Log Statistics
291class LogStatistics {
292    size_t mSizes[LOG_ID_MAX];
293    size_t mElements[LOG_ID_MAX];
294    size_t mSizesTotal[LOG_ID_MAX];
295    size_t mElementsTotal[LOG_ID_MAX];
296    bool enable;
297
298    // uid to size list
299    typedef LogHashtable<uid_t, UidEntry> uidTable_t;
300    uidTable_t uidTable[LOG_ID_MAX];
301
302    // pid to uid list
303    typedef LogHashtable<pid_t, PidEntry> pidTable_t;
304    pidTable_t pidTable;
305
306    // tid to uid list
307    typedef LogHashtable<pid_t, TidEntry> tidTable_t;
308    tidTable_t tidTable;
309
310    // tag list
311    typedef LogHashtable<uint32_t, TagEntry> tagTable_t;
312    tagTable_t tagTable;
313
314public:
315    LogStatistics();
316
317    void enableStatistics() { enable = true; }
318
319    void add(LogBufferElement *entry);
320    void subtract(LogBufferElement *entry);
321    // entry->setDropped(1) must follow this call
322    void drop(LogBufferElement *entry);
323    // Correct for merging two entries referencing dropped content
324    void erase(LogBufferElement *e) { --mElements[e->getLogId()]; }
325
326    std::unique_ptr<const UidEntry *[]> sort(size_t n, log_id i) { return uidTable[i].sort(n); }
327
328    // fast track current value by id only
329    size_t sizes(log_id_t id) const { return mSizes[id]; }
330    size_t elements(log_id_t id) const { return mElements[id]; }
331    size_t sizesTotal(log_id_t id) const { return mSizesTotal[id]; }
332    size_t elementsTotal(log_id_t id) const { return mElementsTotal[id]; }
333
334    // *strp = malloc, balance with free
335    void format(char **strp, uid_t uid, unsigned int logMask);
336
337    // helper (must be locked directly or implicitly by mLogElementsLock)
338    char *pidToName(pid_t pid);
339    uid_t pidToUid(pid_t pid);
340    char *uidToName(uid_t uid);
341};
342
343#endif // _LOGD_LOG_STATISTICS_H__
344