+++ /dev/null
-/* -*- Mode: C; tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*- */
-/*
- * Detailed statistics management. For simple stats like total number of
- * "get" requests, we use inline code in memcached.c and friends, but when
- * stats detail mode is activated, the code here records more information.
- *
- * Author:
- * Steven Grimm <sgrimm@facebook.com>
- */
-#include "memcached.h"
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <assert.h>
-
-/*
- * Stats are tracked on the basis of key prefixes. This is a simple
- * fixed-size hash of prefixes; we run the prefixes through the same
- * CRC function used by the cache hashtable.
- */
-typedef struct _prefix_stats PREFIX_STATS;
-struct _prefix_stats {
- char *prefix;
- size_t prefix_len;
- uint64_t num_gets;
- uint64_t num_sets;
- uint64_t num_deletes;
- uint64_t num_hits;
- PREFIX_STATS *next;
-};
-
-#define PREFIX_HASH_SIZE 256
-
-static PREFIX_STATS *prefix_stats[PREFIX_HASH_SIZE];
-static int num_prefixes = 0;
-static int total_prefix_size = 0;
-
-void stats_prefix_init() {
- memset(prefix_stats, 0, sizeof(prefix_stats));
-}
-
-/*
- * Cleans up all our previously collected stats. NOTE: the stats lock is
- * assumed to be held when this is called.
- */
-void stats_prefix_clear() {
- int i;
-
- for (i = 0; i < PREFIX_HASH_SIZE; i++) {
- PREFIX_STATS *cur, *next;
- for (cur = prefix_stats[i]; cur != NULL; cur = next) {
- next = cur->next;
- free(cur->prefix);
- free(cur);
- }
- prefix_stats[i] = NULL;
- }
- num_prefixes = 0;
- total_prefix_size = 0;
-}
-
-/*
- * Returns the stats structure for a prefix, creating it if it's not already
- * in the list.
- */
-/*@null@*/
-static PREFIX_STATS *stats_prefix_find(const char *key, const size_t nkey) {
- PREFIX_STATS *pfs;
- uint32_t hashval;
- size_t length;
- bool bailout = true;
-
- assert(key != NULL);
-
- for (length = 0; length < nkey && key[length] != '\0'; length++) {
- if (key[length] == settings.prefix_delimiter) {
- bailout = false;
- break;
- }
- }
-
- if (bailout) {
- return NULL;
- }
-
- hashval = hash(key, length, 0) % PREFIX_HASH_SIZE;
-
- for (pfs = prefix_stats[hashval]; NULL != pfs; pfs = pfs->next) {
- if (strncmp(pfs->prefix, key, length) == 0)
- return pfs;
- }
-
- pfs = calloc(sizeof(PREFIX_STATS), 1);
- if (NULL == pfs) {
- perror("Can't allocate space for stats structure: calloc");
- return NULL;
- }
-
- pfs->prefix = malloc(length + 1);
- if (NULL == pfs->prefix) {
- perror("Can't allocate space for copy of prefix: malloc");
- free(pfs);
- return NULL;
- }
-
- strncpy(pfs->prefix, key, length);
- pfs->prefix[length] = '\0'; /* because strncpy() sucks */
- pfs->prefix_len = length;
-
- pfs->next = prefix_stats[hashval];
- prefix_stats[hashval] = pfs;
-
- num_prefixes++;
- total_prefix_size += length;
-
- return pfs;
-}
-
-/*
- * Records a "get" of a key.
- */
-void stats_prefix_record_get(const char *key, const size_t nkey, const bool is_hit) {
- PREFIX_STATS *pfs;
-
- STATS_LOCK();
- pfs = stats_prefix_find(key, nkey);
- if (NULL != pfs) {
- pfs->num_gets++;
- if (is_hit) {
- pfs->num_hits++;
- }
- }
- STATS_UNLOCK();
-}
-
-/*
- * Records a "delete" of a key.
- */
-void stats_prefix_record_delete(const char *key, const size_t nkey) {
- PREFIX_STATS *pfs;
-
- STATS_LOCK();
- pfs = stats_prefix_find(key, nkey);
- if (NULL != pfs) {
- pfs->num_deletes++;
- }
- STATS_UNLOCK();
-}
-
-/*
- * Records a "set" of a key.
- */
-void stats_prefix_record_set(const char *key, const size_t nkey) {
- PREFIX_STATS *pfs;
-
- STATS_LOCK();
- pfs = stats_prefix_find(key, nkey);
- if (NULL != pfs) {
- pfs->num_sets++;
- }
- STATS_UNLOCK();
-}
-
-/*
- * Returns stats in textual form suitable for writing to a client.
- */
-/*@null@*/
-char *stats_prefix_dump(int *length) {
- const char *format = "PREFIX %s get %llu hit %llu set %llu del %llu\r\n";
- PREFIX_STATS *pfs;
- char *buf;
- int i, pos;
- size_t size = 0, written = 0, total_written = 0;
-
- /*
- * Figure out how big the buffer needs to be. This is the sum of the
- * lengths of the prefixes themselves, plus the size of one copy of
- * the per-prefix output with 20-digit values for all the counts,
- * plus space for the "END" at the end.
- */
- STATS_LOCK();
- size = strlen(format) + total_prefix_size +
- num_prefixes * (strlen(format) - 2 /* %s */
- + 4 * (20 - 4)) /* %llu replaced by 20-digit num */
- + sizeof("END\r\n");
- buf = malloc(size);
- if (NULL == buf) {
- perror("Can't allocate stats response: malloc");
- STATS_UNLOCK();
- return NULL;
- }
-
- pos = 0;
- for (i = 0; i < PREFIX_HASH_SIZE; i++) {
- for (pfs = prefix_stats[i]; NULL != pfs; pfs = pfs->next) {
- written = snprintf(buf + pos, size-pos, format,
- pfs->prefix, pfs->num_gets, pfs->num_hits,
- pfs->num_sets, pfs->num_deletes);
- pos += written;
- total_written += written;
- assert(total_written < size);
- }
- }
-
- STATS_UNLOCK();
- memcpy(buf + pos, "END\r\n", 6);
-
- *length = pos + 5;
- return buf;
-}
-
-
-#ifdef UNIT_TEST
-
-/****************************************************************************
- To run unit tests, compile with $(CC) -DUNIT_TEST stats.c assoc.o
- (need assoc.o to get the hash() function).
-****************************************************************************/
-
-struct settings settings;
-
-static char *current_test = "";
-static int test_count = 0;
-static int fail_count = 0;
-
-static void fail(char *what) { printf("\tFAIL: %s\n", what); fflush(stdout); fail_count++; }
-static void test_equals_int(char *what, int a, int b) { test_count++; if (a != b) fail(what); }
-static void test_equals_ptr(char *what, void *a, void *b) { test_count++; if (a != b) fail(what); }
-static void test_equals_str(char *what, const char *a, const char *b) { test_count++; if (strcmp(a, b)) fail(what); }
-static void test_equals_ull(char *what, uint64_t a, uint64_t b) { test_count++; if (a != b) fail(what); }
-static void test_notequals_ptr(char *what, void *a, void *b) { test_count++; if (a == b) fail(what); }
-static void test_notnull_ptr(char *what, void *a) { test_count++; if (NULL == a) fail(what); }
-
-static void test_prefix_find() {
- PREFIX_STATS *pfs1, *pfs2;
-
- pfs1 = stats_prefix_find("abc");
- test_notnull_ptr("initial prefix find", pfs1);
- test_equals_ull("request counts", 0ULL,
- pfs1->num_gets + pfs1->num_sets + pfs1->num_deletes + pfs1->num_hits);
- pfs2 = stats_prefix_find("abc");
- test_equals_ptr("find of same prefix", pfs1, pfs2);
- pfs2 = stats_prefix_find("abc:");
- test_equals_ptr("find of same prefix, ignoring delimiter", pfs1, pfs2);
- pfs2 = stats_prefix_find("abc:d");
- test_equals_ptr("find of same prefix, ignoring extra chars", pfs1, pfs2);
- pfs2 = stats_prefix_find("xyz123");
- test_notequals_ptr("find of different prefix", pfs1, pfs2);
- pfs2 = stats_prefix_find("ab:");
- test_notequals_ptr("find of shorter prefix", pfs1, pfs2);
-}
-
-static void test_prefix_record_get() {
- PREFIX_STATS *pfs;
-
- stats_prefix_record_get("abc:123", 0);
- pfs = stats_prefix_find("abc:123");
- test_equals_ull("get count after get #1", 1, pfs->num_gets);
- test_equals_ull("hit count after get #1", 0, pfs->num_hits);
- stats_prefix_record_get("abc:456", 0);
- test_equals_ull("get count after get #2", 2, pfs->num_gets);
- test_equals_ull("hit count after get #2", 0, pfs->num_hits);
- stats_prefix_record_get("abc:456", 1);
- test_equals_ull("get count after get #3", 3, pfs->num_gets);
- test_equals_ull("hit count after get #3", 1, pfs->num_hits);
- stats_prefix_record_get("def:", 1);
- test_equals_ull("get count after get #4", 3, pfs->num_gets);
- test_equals_ull("hit count after get #4", 1, pfs->num_hits);
-}
-
-static void test_prefix_record_delete() {
- PREFIX_STATS *pfs;
-
- stats_prefix_record_delete("abc:123");
- pfs = stats_prefix_find("abc:123");
- test_equals_ull("get count after delete #1", 0, pfs->num_gets);
- test_equals_ull("hit count after delete #1", 0, pfs->num_hits);
- test_equals_ull("delete count after delete #1", 1, pfs->num_deletes);
- test_equals_ull("set count after delete #1", 0, pfs->num_sets);
- stats_prefix_record_delete("def:");
- test_equals_ull("delete count after delete #2", 1, pfs->num_deletes);
-}
-
-static void test_prefix_record_set() {
- PREFIX_STATS *pfs;
-
- stats_prefix_record_set("abc:123");
- pfs = stats_prefix_find("abc:123");
- test_equals_ull("get count after set #1", 0, pfs->num_gets);
- test_equals_ull("hit count after set #1", 0, pfs->num_hits);
- test_equals_ull("delete count after set #1", 0, pfs->num_deletes);
- test_equals_ull("set count after set #1", 1, pfs->num_sets);
- stats_prefix_record_delete("def:");
- test_equals_ull("set count after set #2", 1, pfs->num_sets);
-}
-
-static void test_prefix_dump() {
- int hashval = hash("abc", 3, 0) % PREFIX_HASH_SIZE;
- char tmp[500];
- char *expected;
- int keynum;
- int length;
-
- test_equals_str("empty stats", "END\r\n", stats_prefix_dump(&length));
- test_equals_int("empty stats length", 5, length);
- stats_prefix_record_set("abc:123");
- expected = "PREFIX abc get 0 hit 0 set 1 del 0\r\nEND\r\n";
- test_equals_str("stats after set", expected, stats_prefix_dump(&length));
- test_equals_int("stats length after set", strlen(expected), length);
- stats_prefix_record_get("abc:123", 0);
- expected = "PREFIX abc get 1 hit 0 set 1 del 0\r\nEND\r\n";
- test_equals_str("stats after get #1", expected, stats_prefix_dump(&length));
- test_equals_int("stats length after get #1", strlen(expected), length);
- stats_prefix_record_get("abc:123", 1);
- expected = "PREFIX abc get 2 hit 1 set 1 del 0\r\nEND\r\n";
- test_equals_str("stats after get #2", expected, stats_prefix_dump(&length));
- test_equals_int("stats length after get #2", strlen(expected), length);
- stats_prefix_record_delete("abc:123");
- expected = "PREFIX abc get 2 hit 1 set 1 del 1\r\nEND\r\n";
- test_equals_str("stats after del #1", expected, stats_prefix_dump(&length));
- test_equals_int("stats length after del #1", strlen(expected), length);
-
- /* The order of results might change if we switch hash functions. */
- stats_prefix_record_delete("def:123");
- expected = "PREFIX abc get 2 hit 1 set 1 del 1\r\n"
- "PREFIX def get 0 hit 0 set 0 del 1\r\n"
- "END\r\n";
- test_equals_str("stats after del #2", expected, stats_prefix_dump(&length));
- test_equals_int("stats length after del #2", strlen(expected), length);
-
- /* Find a key that hashes to the same bucket as "abc" */
- for (keynum = 0; keynum < PREFIX_HASH_SIZE * 100; keynum++) {
- snprintf(tmp, sizeof(tmp), "%d", keynum);
- if (hashval == hash(tmp, strlen(tmp), 0) % PREFIX_HASH_SIZE) {
- break;
- }
- }
- stats_prefix_record_set(tmp);
- snprintf(tmp, sizeof(tmp),
- "PREFIX %d get 0 hit 0 set 1 del 0\r\n"
- "PREFIX abc get 2 hit 1 set 1 del 1\r\n"
- "PREFIX def get 0 hit 0 set 0 del 1\r\n"
- "END\r\n", keynum);
- test_equals_str("stats with two stats in one bucket",
- tmp, stats_prefix_dump(&length));
- test_equals_int("stats length with two stats in one bucket",
- strlen(tmp), length);
-}
-
-static void run_test(char *what, void (*func)(void)) {
- current_test = what;
- test_count = fail_count = 0;
- puts(what);
- fflush(stdout);
-
- stats_prefix_clear();
- (func)();
- printf("\t%d / %d pass\n", (test_count - fail_count), test_count);
-}
-
-/* In case we're compiled in thread mode */
-void mt_stats_lock() { }
-void mt_stats_unlock() { }
-
-main(int argc, char **argv) {
- stats_prefix_init();
- settings.prefix_delimiter = ':';
- run_test("stats_prefix_find", test_prefix_find);
- run_test("stats_prefix_record_get", test_prefix_record_get);
- run_test("stats_prefix_record_delete", test_prefix_record_delete);
- run_test("stats_prefix_record_set", test_prefix_record_set);
- run_test("stats_prefix_dump", test_prefix_dump);
-}
-
-#endif
projects / awesomized / libmemcached / blobdiff