logd: Add Pid statistics

- Optional class of statistics for PID
- Enhance pidToName
- Enhanced uidToName
- Enhance pidToUid
- template sort and iteration

Bug: 19608965
Change-Id: I04a1f02e9851b62987f9b176908134e455f22d1d
diff --git a/logd/LogStatistics.h b/logd/LogStatistics.h
index d5b8762..a65ffe0 100644
--- a/logd/LogStatistics.h
+++ b/logd/LogStatistics.h
@@ -17,6 +17,8 @@
 #ifndef _LOGD_LOG_STATISTICS_H__
 #define _LOGD_LOG_STATISTICS_H__
 
+#include <memory>
+#include <stdlib.h>
 #include <sys/types.h>
 
 #include <log/log.h>
@@ -27,6 +29,52 @@
 #define log_id_for_each(i) \
     for (log_id_t i = LOG_ID_MIN; i < LOG_ID_MAX; i = (log_id_t) (i + 1))
 
+template <typename TKey, typename TEntry>
+class LogHashtable : public android::BasicHashtable<TKey, TEntry> {
+public:
+    std::unique_ptr<const TEntry *[]> sort(size_t n) {
+        if (!n) {
+            std::unique_ptr<const TEntry *[]> sorted(NULL);
+            return sorted;
+        }
+
+        const TEntry **retval = new const TEntry* [n];
+        memset(retval, 0, sizeof(*retval) * n);
+
+        ssize_t index = -1;
+        while ((index = android::BasicHashtable<TKey, TEntry>::next(index)) >= 0) {
+            const TEntry &entry = android::BasicHashtable<TKey, TEntry>::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;
+            }
+        }
+        std::unique_ptr<const TEntry *[]> sorted(retval);
+        return sorted;
+    }
+
+    // Iteration handler for the sort method output
+    static ssize_t next(ssize_t index, std::unique_ptr<const TEntry *[]> &sorted, size_t n) {
+        ++index;
+        if (!sorted.get() || (index < 0) || (n <= (size_t)index) || !sorted[index]
+         || (sorted[index]->getSizes() <= (sorted[0]->getSizes() / 100))) {
+            return -1;
+        }
+        return index;
+    }
+
+    ssize_t next(ssize_t index) {
+        return android::BasicHashtable<TKey, TEntry>::next(index);
+    }
+};
+
 struct UidEntry {
     const uid_t uid;
     size_t size;
@@ -39,27 +87,55 @@
     inline bool subtract(size_t s) { size -= s; return !size; }
 };
 
+struct PidEntry {
+    const pid_t pid;
+    uid_t uid;
+    char *name;
+    size_t size;
+
+    PidEntry(pid_t p, uid_t u, char *n):pid(p),uid(u),name(n),size(0) { }
+    PidEntry(const PidEntry &c):
+        pid(c.pid),
+        uid(c.uid),
+        name(c.name ? strdup(c.name) : NULL),
+        size(c.size) { }
+    ~PidEntry() { free(name); }
+
+    const pid_t&getKey() const { return pid; }
+    const uid_t&getUid() const { return uid; }
+    uid_t&setUid(uid_t u) { return uid = u; }
+    const char*getName() const { return name; }
+    char *setName(char *n) { free(name); return name = n; }
+    size_t getSizes() const { return size; }
+    inline void add(size_t s) { size += s; }
+    inline bool subtract(size_t s) { size -= s; return !size; }
+};
+
 // Log Statistics
 class LogStatistics {
     size_t mSizes[LOG_ID_MAX];
     size_t mElements[LOG_ID_MAX];
     size_t mSizesTotal[LOG_ID_MAX];
     size_t mElementsTotal[LOG_ID_MAX];
+    bool enable;
 
     // uid to size list
-    typedef android::BasicHashtable<uid_t, UidEntry> uidTable_t;
+    typedef LogHashtable<uid_t, UidEntry> uidTable_t;
     uidTable_t uidTable[LOG_ID_MAX];
 
+    // pid to uid list
+    typedef LogHashtable<pid_t, PidEntry> pidTable_t;
+    pidTable_t pidTable;
+
 public:
     LogStatistics();
 
-    void enableStatistics() { }
+    void enableStatistics() { enable = true; }
 
     void add(LogBufferElement *entry);
     void subtract(LogBufferElement *entry);
 
-    // Caller must delete array
-    const UidEntry **sort(size_t n, log_id i);
+    std::unique_ptr<const UidEntry *[]> sort(size_t n, log_id i) { return uidTable[i].sort(n); }
 
     // fast track current value by id only
     size_t sizes(log_id_t id) const { return mSizes[id]; }