INTERNAL: Refactor lq_detect_buffer struct

lqdetect.c

@@ -6,15 +6,17 @@
 #include <pthread.h>
 #include <sys/time.h>
 #include <assert.h>
+#include <math.h>
 
 #include "memcached/util.h"
 
 #define LQ_THRESHOLD_DEFAULT 4000
 #define LQ_QUERY_SIZE  (64*2+64) /* bop get (longest query) : "<longest bkey>..<longest bkey> efilter <offset> <count> delete" */
 #define LQ_KEY_SIZE    250       /* the max size of key string */
 #define LQ_SAVE_CNT    20        /* save key count */
-#define LQ_INPUT_SIZE  500       /* the size of input(time, ip, command, argument) */
 #define LQ_STAT_STRLEN 300       /* max length of stats */
+#define LQ_TIME_SIZE   16        /* time string size */
+#define LQ_IP_SIZE     39        /* ipv6 max string size */
 
 /* lqdetect state */
 #define LQ_EXPLICIT_STOP 0       /* stop by user request */
@@ -58,13 +60,14 @@ struct lq_detect_stats {
 struct lq_detect_argument {
     char query[LQ_QUERY_SIZE];
     char key[LQ_KEY_SIZE+1];
+    char time[LQ_TIME_SIZE+1];
+    char client_ip[LQ_IP_SIZE+1];
     uint32_t count;
     uint32_t overhead;
 };
 
 /* lqdetect buffer structure */
 struct lq_detect_buffer {
-    char *data;
     uint32_t offset;
     uint32_t ntotal;
     uint32_t nsaved;
@@ -109,9 +112,6 @@ static bool is_command_duplicated(char *key, enum lq_detect_command cmd, struct
                 }
             }
         }
-        if (arg->count == 0) {
-            snprintf(arg->key, sizeof(arg->key), "%s", key);
-        }
         break;
     }
     return false;
@@ -124,7 +124,6 @@ static void do_lqdetect_write(char *client_ip, char *key,
     struct   timeval val;
     struct   lq_detect_buffer *buffer = &lqdetect.buffer[cmd];
     uint32_t nsaved = buffer->nsaved;
-    uint32_t length = ((nsaved+1) * LQ_INPUT_SIZE);
     int keylen = strlen(key);
     char keybuf[LQ_KEY_SIZE+1];
     char *keyptr = key;
@@ -142,11 +141,12 @@ static void do_lqdetect_write(char *client_ip, char *key,
     gettimeofday(&val, NULL);
     ptm = localtime(&val.tv_sec);
 
-    snprintf(buffer->data + buffer->offset, length - buffer->offset,
-             "%02d:%02d:%02d.%06ld %s <%u> %s %s %s\n",
-             ptm->tm_hour, ptm->tm_min, ptm->tm_sec, (long)val.tv_usec,
-             client_ip, arg->overhead, command_str[cmd], keyptr, arg->query);
-    buffer->offset += strlen(buffer->data + buffer->offset);
+    buffer->offset += snprintf(arg->time, sizeof(arg->time), "%02d:%02d:%02d.%06ld",
+                               ptm->tm_hour, ptm->tm_min, ptm->tm_sec, (long)val.tv_usec) + 1; /* +1 for space */
+    buffer->offset += snprintf(arg->client_ip, sizeof(arg->client_ip), "%s", client_ip) + 1; /* +1 for space */
+    buffer->offset += snprintf(arg->key, sizeof(arg->key), "%s", key) + 1; /* +1 for space */
+    buffer->offset += (int)log10(arg->overhead) + 1 + 3; /* overhead + < + > + space */
+    buffer->offset += strlen(command_str[cmd]) + strlen(arg->query) + 2; /* query + command + spaces */
     lqdetect.arg[cmd][nsaved] = *arg;
     buffer->nsaved += 1;
 }
@@ -220,26 +220,11 @@ int lqdetect_init(EXTENSION_LOGGER_DESCRIPTOR *logger)
     memset(lqdetect.buffer, 0, LQ_CMD_NUM * sizeof(struct lq_detect_buffer));
     memset(&lqdetect.stats, 0, sizeof(struct lq_detect_stats));
     for (int ii = 0; ii < LQ_CMD_NUM; ii++) {
-        lqdetect.buffer[ii].data = malloc(LQ_SAVE_CNT * LQ_INPUT_SIZE);
-        if (lqdetect.buffer[ii].data == NULL) {
-            while (--ii >= 0) {
-                free(lqdetect.buffer[ii].data);
-            }
-            return -1;
-        }
         memset(lqdetect.arg[ii], 0, LQ_SAVE_CNT * sizeof(struct lq_detect_argument));
     }
     return 0;
 }
 
-void lqdetect_final(void)
-{
-    for (int ii = 0; ii < LQ_CMD_NUM; ii++) {
-        free(lqdetect.buffer[ii].data);
-        lqdetect.buffer[ii].data = NULL;
-    }
-}
-
 int lqdetect_start(uint32_t threshold, bool *already_started)
 {
     int ret = 0;
@@ -320,20 +305,28 @@ char *lqdetect_stats(void)
 char *lqdetect_result_get(int *size)
 {
     int offset = 0;
-    int length = 32 * LQ_CMD_NUM; // header length
+    int length = 1; /* for null-terminator */
     char *str;
 
     pthread_mutex_lock(&lqdetect.lock);
     for (int i = 0; i < LQ_CMD_NUM; i++) {
+        if (lqdetect.buffer[i].ntotal == 0) {
+            length += strlen(command_str[i]) + 1 + 4; /* command + space + ": 0\n" */
+            continue;
+        }
         length += lqdetect.buffer[i].offset;
+        length += strlen(command_str[i]) + (int)log10(lqdetect.buffer[i].ntotal) + 1 + 4; /* command + space + ": " + number + "\n" */
     }
     str = (char*)malloc(length);
     if (str != NULL) {
         for (int i = 0; i < LQ_CMD_NUM; i++) {
             struct lq_detect_buffer *ldb = &lqdetect.buffer[i];
             offset += snprintf(str + offset, length - offset, "%s : %u\n", command_str[i], ldb->ntotal);
-            if (ldb->ntotal > 0) {
-                offset += snprintf(str + offset, length - offset, "%s", ldb->data);
+            for (int j = 0; j < ldb->nsaved; j++) {
+                offset += snprintf(str + offset, length - offset,
+                    "%s %s <%u> %s %s %s\n",
+                    lqdetect.arg[i][j].time, lqdetect.arg[i][j].client_ip, lqdetect.arg[i][j].overhead,
+                    command_str[i], lqdetect.arg[i][j].key, lqdetect.arg[i][j].query);
             }
         }
     }

lqdetect.h

@@ -12,7 +12,6 @@
 extern bool lqdetect_in_use;
 
 int lqdetect_init(EXTENSION_LOGGER_DESCRIPTOR *logger);
-void lqdetect_final(void);
 char *lqdetect_result_get(int *size);
 int lqdetect_start(uint32_t threshold, bool *already_started);
 void lqdetect_stop(bool *already_stopped);

memcached.c

@@ -15861,9 +15861,6 @@ int main (int argc, char **argv)
     /* 6) destroy data structures */
 #ifdef COMMAND_LOGGING
     cmdlog_final(); /* finalize command logging */
-#endif
-#ifdef DETECT_LONG_QUERY
-    lqdetect_final(); /* finalize long query detection */
 #endif
     mc_engine.v1->destroy(mc_engine.v0);
     mc_logger->log(EXTENSION_LOG_INFO, NULL, "Memcached engine destroyed.\n");