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Diffstat (limited to 'examples/redis-unstable/src/expire.c')
| -rw-r--r-- | examples/redis-unstable/src/expire.c | 932 |
1 files changed, 0 insertions, 932 deletions
diff --git a/examples/redis-unstable/src/expire.c b/examples/redis-unstable/src/expire.c deleted file mode 100644 index af0a103..0000000 --- a/examples/redis-unstable/src/expire.c +++ /dev/null @@ -1,932 +0,0 @@ -/* Implementation of EXPIRE (keys with fixed time to live). - * - * ---------------------------------------------------------------------------- - * - * Copyright (c) 2009-Present, Redis Ltd. - * All rights reserved. - * - * Licensed under your choice of (a) the Redis Source Available License 2.0 - * (RSALv2); or (b) the Server Side Public License v1 (SSPLv1); or (c) the - * GNU Affero General Public License v3 (AGPLv3). - */ - -#include "server.h" -#include "cluster.h" -#include "redisassert.h" - -/*----------------------------------------------------------------------------- - * Incremental collection of expired keys. - * - * When keys are accessed they are expired on-access. However we need a - * mechanism in order to ensure keys are eventually removed when expired even - * if no access is performed on them. - *----------------------------------------------------------------------------*/ - -/* Constants table from pow(0.98, 1) to pow(0.98, 16). - * Help calculating the db->avg_ttl. */ -static double avg_ttl_factor[16] = {0.98, 0.9604, 0.941192, 0.922368, 0.903921, 0.885842, 0.868126, 0.850763, 0.833748, 0.817073, 0.800731, 0.784717, 0.769022, 0.753642, 0.738569, 0.723798}; - -/* Helper function for the activeExpireCycle() function. - * This function will try to expire the key-value entry that is stored in the - * hash table entry 'de' of the 'expires' hash table of a Redis database. - * - * If the key is found to be expired, it is removed from the database and - * 1 is returned. Otherwise no operation is performed and 0 is returned. - * - * When a key is expired, server.stat_expiredkeys is incremented. - * - * The parameter 'now' is the current time in milliseconds as is passed - * to the function to avoid too many gettimeofday() syscalls. */ -int activeExpireCycleTryExpire(redisDb *db, kvobj *kv, long long now) { - if (now < kvobjGetExpire(kv)) - return 0; - - enterExecutionUnit(1, 0); - sds key = kvobjGetKey(kv); - robj *keyobj = createStringObject(key,sdslen(key)); - deleteExpiredKeyAndPropagate(db,keyobj); - decrRefCount(keyobj); - exitExecutionUnit(); - /* Propagate the DEL command */ - postExecutionUnitOperations(); - return 1; -} - -/* Try to expire a few timed out keys. The algorithm used is adaptive and - * will use few CPU cycles if there are few expiring keys, otherwise - * it will get more aggressive to avoid that too much memory is used by - * keys that can be removed from the keyspace. - * - * Every expire cycle tests multiple databases: the next call will start - * again from the next db. No more than CRON_DBS_PER_CALL databases are - * tested at every iteration. - * - * The function can perform more or less work, depending on the "type" - * argument. It can execute a "fast cycle" or a "slow cycle". The slow - * cycle is the main way we collect expired cycles: this happens with - * the "server.hz" frequency (usually 10 hertz). - * - * However the slow cycle can exit for timeout, since it used too much time. - * For this reason the function is also invoked to perform a fast cycle - * at every event loop cycle, in the beforeSleep() function. The fast cycle - * will try to perform less work, but will do it much more often. - * - * The following are the details of the two expire cycles and their stop - * conditions: - * - * If type is ACTIVE_EXPIRE_CYCLE_FAST the function will try to run a - * "fast" expire cycle that takes no longer than ACTIVE_EXPIRE_CYCLE_FAST_DURATION - * microseconds, and is not repeated again before the same amount of time. - * The cycle will also refuse to run at all if the latest slow cycle did not - * terminate because of a time limit condition. - * - * If type is ACTIVE_EXPIRE_CYCLE_SLOW, that normal expire cycle is - * executed, where the time limit is a percentage of the REDIS_HZ period - * as specified by the ACTIVE_EXPIRE_CYCLE_SLOW_TIME_PERC define. In the - * fast cycle, the check of every database is interrupted once the number - * of already expired keys in the database is estimated to be lower than - * a given percentage, in order to avoid doing too much work to gain too - * little memory. - * - * The configured expire "effort" will modify the baseline parameters in - * order to do more work in both the fast and slow expire cycles. - */ - -#define ACTIVE_EXPIRE_CYCLE_KEYS_PER_LOOP 20 /* Keys for each DB loop. */ -#define ACTIVE_EXPIRE_CYCLE_FAST_DURATION 1000 /* Microseconds. */ -#define ACTIVE_EXPIRE_CYCLE_SLOW_TIME_PERC 25 /* Max % of CPU to use. */ -#define ACTIVE_EXPIRE_CYCLE_ACCEPTABLE_STALE 10 /* % of stale keys after which - we do extra efforts. */ - -#define HFE_DB_BASE_ACTIVE_EXPIRE_FIELDS_PER_SEC 10000 - -/* Data used by the expire dict scan callback. */ -typedef struct { - redisDb *db; - long long now; - unsigned long sampled; /* num keys checked */ - unsigned long expired; /* num keys expired */ - long long ttl_sum; /* sum of ttl for key with ttl not yet expired */ - int ttl_samples; /* num keys with ttl not yet expired */ -} expireScanData; - -void expireScanCallback(void *privdata, const dictEntry *de, dictEntryLink plink) { - UNUSED(plink); - kvobj *kv = dictGetKV(de); - expireScanData *data = privdata; - long long ttl = kvobjGetExpire(kv) - data->now; - if (activeExpireCycleTryExpire(data->db, kv, data->now)) { - data->expired++; - } - if (ttl > 0) { - /* We want the average TTL of keys yet not expired. */ - data->ttl_sum += ttl; - data->ttl_samples++; - } - data->sampled++; -} - -static inline int expirySamplingShouldSkipDict(dict *d, int didx) { - long long numkeys = dictSize(d); - unsigned long buckets = dictBuckets(d); - /* When there are less than 1% filled buckets, sampling the key - * space is expensive, so stop here waiting for better times... - * The dictionary will be resized asap. */ - if (buckets > DICT_HT_INITIAL_SIZE && (numkeys * 100/buckets < 1)) { - return 1; - } - - /* During atomic slot migration, keys that are being imported are in an - * intermediate state. we cannot expire them and therefore skip them. */ - if (!clusterCanAccessKeysInSlot(didx)) return 1; - - return 0; -} - -/* SubexpireCtx passed to activeSubexpiresCb() */ -typedef struct SubexpireCtx { - uint32_t fieldsToExpireQuota; - redisDb *db; - int slot; -} SubexpireCtx; - -/* - * Active sub-expiration callback - * - * Called by activeSubexpires() for each key registered in the subexpires DB - * with an expiration-time on its "elements" that are less than or equal current - * time. - * - * This callback performs the following actions for each hash: - * - Delete expired fields as by calling ebExpire(hash) - * - If afterward there are future fields to expire, it will update the hash in - * HFE DB with the next hash-field minimum expiration time by returning - * ACT_UPDATE_EXP_ITEM. - * - If the hash has no more fields to expire, it is removed from the HFE DB - * by returning ACT_REMOVE_EXP_ITEM. - * - If hash has no more fields afterward, it will remove the hash from keyspace. - */ -static ExpireAction activeSubexpiresCb(eItem item, void *ctx) { - SubexpireCtx *subexCtx = ctx; - - /* If no more quota left for this callback, stop */ - if (subexCtx->fieldsToExpireQuota == 0) - return ACT_STOP_ACTIVE_EXP; - - kvobj *kv = (kvobj *) item; - - /* currently we only support hash type sub-expire */ - assert(kv->type == OBJ_HASH); - uint64_t nextExpTime = hashTypeActiveExpire(subexCtx->db,kv, - &subexCtx->fieldsToExpireQuota, 0); - - /* If hash has no more fields to expire or got deleted, indicate - * to remove it from HFE DB to the caller ebExpire() */ - if (nextExpTime == EB_EXPIRE_TIME_INVALID || nextExpTime == 0) { - return ACT_REMOVE_EXP_ITEM; - } else { - /* Hash has more fields to expire. Update next expiration time of the hash - * and indicate to add it back to global HFE DS */ - ebSetMetaExpTime(hashGetExpireMeta(item), nextExpTime); - return ACT_UPDATE_EXP_ITEM; - } -} - -/* DB active expire and update hashes with time-expiration on fields. - * - * The callback function activeSubexpiresCb() is invoked for each hash registered - * in the subexpires DB with an expiration-time less than or equal to the - * current time. This callback performs the following actions for each hash: - * - If the hash has one or more fields to expire, it will delete those fields. - * - If there are more fields to expire, it will update the hash with the next - * expiration time in subexpires DB. - * - If the hash has no more fields to expire, it is removed from the subexpires DB. - * - If the hash has no more fields, it is removed from the main DB. - * - * Returns number of fields active-expired. - */ -uint64_t activeSubexpires(redisDb *db, int slot, uint32_t maxFieldsToExpire) { - SubexpireCtx ctx = { .db = db, .fieldsToExpireQuota = maxFieldsToExpire, .slot = slot }; - ExpireInfo info = { - .maxToExpire = UINT64_MAX, /* Only maxFieldsToExpire play a role */ - .onExpireItem = activeSubexpiresCb, - .ctx = &ctx, - .now = commandTimeSnapshot(), - .itemsExpired = 0}; - - estoreActiveExpire(db->subexpires, slot, &info); - - /* Return number of fields active-expired */ - return maxFieldsToExpire - ctx.fieldsToExpireQuota; -} - -/* Active expiration Cycle for hash-fields. - * - * Note that releasing fields is expected to be more predictable and rewarding - * than releasing keys because it is stored in `ebuckets` DS which optimized for - * active expiration and in addition the deletion of fields is simple to handle. */ -static inline void activeSubexpiresCycle(int type) { - /* Remember current db across calls */ - static unsigned int currentDb = 0; - static int currentSlot = -1; - - /* Tracks the count of fields actively expired for the current database. - * This count continues as long as it fails to actively expire all expired - * fields of currentDb, indicating a possible need to adjust the value of - * maxToExpire. */ - static uint64_t activeExpirySequence = 0; - /* Threshold for adjusting maxToExpire */ - const uint32_t EXPIRED_FIELDS_TH = 1000000; - - redisDb *db = server.db + currentDb; - - /* If db is empty, move to next db and return */ - if (estoreIsEmpty(db->subexpires)) { - activeExpirySequence = 0; - currentDb = (currentDb + 1) % server.dbnum; - return; - } - if (currentSlot == -1) - currentSlot = estoreGetFirstNonEmptyBucket(db->subexpires); - - /* During atomic slot migration, keys that are being imported are in an - * intermediate state. We cannot expire them and therefore skip them. */ - if (!clusterCanAccessKeysInSlot(currentSlot)) { - /* Move to next non-empty subexpires slot */ - currentSlot = estoreGetNextNonEmptyBucket(db->subexpires, currentSlot); - if (currentSlot == -1) - currentDb = (currentDb + 1) % server.dbnum; /* Move to next db */ - return; - } - - /* Maximum number of fields to actively expire on a single call */ - uint32_t maxToExpire = HFE_DB_BASE_ACTIVE_EXPIRE_FIELDS_PER_SEC / server.hz; - - /* If running for a while and didn't manage to active-expire all expired fields of - * currentDb (i.e. activeExpirySequence becomes significant) then adjust maxToExpire */ - if ((activeExpirySequence > EXPIRED_FIELDS_TH) && (type == ACTIVE_EXPIRE_CYCLE_SLOW)) { - /* maxToExpire is multiplied by a factor between 1 and 32, proportional to - * the number of times activeExpirySequence exceeded EXPIRED_FIELDS_TH */ - uint64_t factor = activeExpirySequence / EXPIRED_FIELDS_TH; - maxToExpire *= (factor<32) ? factor : 32; - } - - if (activeSubexpires(db, currentSlot, maxToExpire) == maxToExpire) { - /* active-expire reached maxToExpire limit */ - activeExpirySequence += maxToExpire; - } else { - /* Managed to active-expire all expired fields of currentDb */ - activeExpirySequence = 0; - /* Move to next non-empty subexpires slot */ - currentSlot = estoreGetNextNonEmptyBucket(db->subexpires, currentSlot); - if (currentSlot == -1) - currentDb = (currentDb + 1) % server.dbnum; - } -} - -void activeExpireCycle(int type) { - /* Adjust the running parameters according to the configured expire - * effort. The default effort is 1, and the maximum configurable effort - * is 10. */ - unsigned long - effort = server.active_expire_effort-1, /* Rescale from 0 to 9. */ - config_keys_per_loop = ACTIVE_EXPIRE_CYCLE_KEYS_PER_LOOP + - ACTIVE_EXPIRE_CYCLE_KEYS_PER_LOOP/4*effort, - config_cycle_fast_duration = ACTIVE_EXPIRE_CYCLE_FAST_DURATION + - ACTIVE_EXPIRE_CYCLE_FAST_DURATION/4*effort, - config_cycle_slow_time_perc = ACTIVE_EXPIRE_CYCLE_SLOW_TIME_PERC + - 2*effort, - config_cycle_acceptable_stale = ACTIVE_EXPIRE_CYCLE_ACCEPTABLE_STALE- - effort; - - /* This function has some global state in order to continue the work - * incrementally across calls. */ - static unsigned int current_db = 0; /* Next DB to test. */ - static int timelimit_exit = 0; /* Time limit hit in previous call? */ - static long long last_fast_cycle = 0; /* When last fast cycle ran. */ - - int j, iteration = 0; - int dbs_per_call = CRON_DBS_PER_CALL; - int dbs_performed = 0; - long long start = ustime(), timelimit, elapsed; - - /* If 'expire' action is paused, for whatever reason, then don't expire any key. - * Typically, at the end of the pause we will properly expire the key OR we - * will have failed over and the new primary will send us the expire. */ - if (isPausedActionsWithUpdate(PAUSE_ACTION_EXPIRE)) return; - - if (type == ACTIVE_EXPIRE_CYCLE_FAST) { - /* Don't start a fast cycle if the previous cycle did not exit - * for time limit, unless the percentage of estimated stale keys is - * too high. Also never repeat a fast cycle for the same period - * as the fast cycle total duration itself. */ - if (!timelimit_exit && - server.stat_expired_stale_perc < config_cycle_acceptable_stale) - return; - - if (start < last_fast_cycle + (long long)config_cycle_fast_duration*2) - return; - - last_fast_cycle = start; - } - - /* We usually should test CRON_DBS_PER_CALL per iteration, with - * two exceptions: - * - * 1) Don't test more DBs than we have. - * 2) If last time we hit the time limit, we want to scan all DBs - * in this iteration, as there is work to do in some DB and we don't want - * expired keys to use memory for too much time. */ - if (dbs_per_call > server.dbnum || timelimit_exit) - dbs_per_call = server.dbnum; - - /* We can use at max 'config_cycle_slow_time_perc' percentage of CPU - * time per iteration. Since this function gets called with a frequency of - * server.hz times per second, the following is the max amount of - * microseconds we can spend in this function. */ - timelimit = config_cycle_slow_time_perc*1000000/server.hz/100; - timelimit_exit = 0; - if (timelimit <= 0) timelimit = 1; - - if (type == ACTIVE_EXPIRE_CYCLE_FAST) - timelimit = config_cycle_fast_duration; /* in microseconds. */ - - /* Accumulate some global stats as we expire keys, to have some idea - * about the number of keys that are already logically expired, but still - * existing inside the database. */ - long total_sampled = 0; - long total_expired = 0; - - /* Try to smoke-out bugs (server.also_propagate should be empty here) */ - serverAssert(server.also_propagate.numops == 0); - - /* Stop iteration when one of the following conditions is met: - * - * 1) We have checked a sufficient number of databases with expiration time. - * 2) The time limit has been exceeded. - * 3) All databases have been traversed. */ - for (j = 0; dbs_performed < dbs_per_call && timelimit_exit == 0 && j < server.dbnum; j++) { - /* Scan callback data including expired and checked count per iteration. */ - expireScanData data; - data.ttl_sum = 0; - data.ttl_samples = 0; - - redisDb *db = server.db+(current_db % server.dbnum); - data.db = db; - - int db_done = 0; /* The scan of the current DB is done? */ - int update_avg_ttl_times = 0, repeat = 0; - - /* Increment the DB now so we are sure if we run out of time - * in the current DB we'll restart from the next. This allows to - * distribute the time evenly across DBs. */ - current_db++; - - /* Interleaving sub-expiration with key expiration. Better call it before - * handling expired keys because ebuckets is optimized for active expiration */ - activeSubexpiresCycle(type); - - if (kvstoreSize(db->expires)) - dbs_performed++; - - /* Continue to expire if at the end of the cycle there are still - * a big percentage of keys to expire, compared to the number of keys - * we scanned. The percentage, stored in config_cycle_acceptable_stale - * is not fixed, but depends on the Redis configured "expire effort". */ - do { - unsigned long num; - iteration++; - - /* If there is nothing to expire try next DB ASAP. */ - if ((num = kvstoreSize(db->expires)) == 0) { - db->avg_ttl = 0; - break; - } - data.now = mstime(); - - /* The main collection cycle. Scan through keys among keys - * with an expire set, checking for expired ones. */ - data.sampled = 0; - data.expired = 0; - - if (num > config_keys_per_loop) - num = config_keys_per_loop; - - /* Here we access the low level representation of the hash table - * for speed concerns: this makes this code coupled with dict.c, - * but it hardly changed in ten years. - * - * Note that certain places of the hash table may be empty, - * so we want also a stop condition about the number of - * buckets that we scanned. However scanning for free buckets - * is very fast: we are in the cache line scanning a sequential - * array of NULL pointers, so we can scan a lot more buckets - * than keys in the same time. */ - long max_buckets = num*20; - long checked_buckets = 0; - - int origin_ttl_samples = data.ttl_samples; - - while (data.sampled < num && checked_buckets < max_buckets) { - db->expires_cursor = kvstoreScan(db->expires, db->expires_cursor, -1, expireScanCallback, expirySamplingShouldSkipDict, &data); - if (db->expires_cursor == 0) { - db_done = 1; - break; - } - checked_buckets++; - } - total_expired += data.expired; - total_sampled += data.sampled; - - /* If find keys with ttl not yet expired, we need to update the average TTL stats once. */ - if (data.ttl_samples - origin_ttl_samples > 0) update_avg_ttl_times++; - - /* We don't repeat the cycle for the current database if the db is done - * for scanning or an acceptable number of stale keys (logically expired - * but yet not reclaimed). */ - repeat = db_done ? 0 : (data.sampled == 0 || (data.expired * 100 / data.sampled) > config_cycle_acceptable_stale); - - /* We can't block forever here even if there are many keys to - * expire. So after a given amount of microseconds return to the - * caller waiting for the other active expire cycle. */ - if ((iteration & 0xf) == 0 || !repeat) { /* Update the average TTL stats every 16 iterations or about to exit. */ - /* Update the average TTL stats for this database, - * because this may reach the time limit. */ - if (data.ttl_samples) { - long long avg_ttl = data.ttl_sum / data.ttl_samples; - - /* Do a simple running average with a few samples. - * We just use the current estimate with a weight of 2% - * and the previous estimate with a weight of 98%. */ - if (db->avg_ttl == 0) { - db->avg_ttl = avg_ttl; - } else { - /* The origin code is as follow. - * for (int i = 0; i < update_avg_ttl_times; i++) { - * db->avg_ttl = (db->avg_ttl/50)*49 + (avg_ttl/50); - * } - * We can convert the loop into a sum of a geometric progression. - * db->avg_ttl = db->avg_ttl * pow(0.98, update_avg_ttl_times) + - * avg_ttl / 50 * (pow(0.98, update_avg_ttl_times - 1) + ... + 1) - * = db->avg_ttl * pow(0.98, update_avg_ttl_times) + - * avg_ttl * (1 - pow(0.98, update_avg_ttl_times)) - * = avg_ttl + (db->avg_ttl - avg_ttl) * pow(0.98, update_avg_ttl_times) - * Notice that update_avg_ttl_times is between 1 and 16, we use a constant table - * to accelerate the calculation of pow(0.98, update_avg_ttl_times).*/ - db->avg_ttl = avg_ttl + (db->avg_ttl - avg_ttl) * avg_ttl_factor[update_avg_ttl_times - 1] ; - } - update_avg_ttl_times = 0; - data.ttl_sum = 0; - data.ttl_samples = 0; - } - if ((iteration & 0xf) == 0) { /* check time limit every 16 iterations. */ - elapsed = ustime()-start; - if (elapsed > timelimit) { - timelimit_exit = 1; - server.stat_expired_time_cap_reached_count++; - break; - } - } - } - } while (repeat); - } - - elapsed = ustime()-start; - server.stat_expire_cycle_time_used += elapsed; - latencyAddSampleIfNeeded("expire-cycle",elapsed/1000); - - /* Update our estimate of keys existing but yet to be expired. - * Running average with this sample accounting for 5%. */ - double current_perc; - if (total_sampled) { - current_perc = (double)total_expired/total_sampled; - } else - current_perc = 0; - server.stat_expired_stale_perc = (current_perc*0.05)+ - (server.stat_expired_stale_perc*0.95); -} - -/*----------------------------------------------------------------------------- - * Expires of keys created in writable slaves - * - * Normally slaves do not process expires: they wait the masters to synthesize - * DEL operations in order to retain consistency. However writable slaves are - * an exception: if a key is created in the slave and an expire is assigned - * to it, we need a way to expire such a key, since the master does not know - * anything about such a key. - * - * In order to do so, we track keys created in the slave side with an expire - * set, and call the expireSlaveKeys() function from time to time in order to - * reclaim the keys if they already expired. - * - * Note that the use case we are trying to cover here, is a popular one where - * slaves are put in writable mode in order to compute slow operations in - * the slave side that are mostly useful to actually read data in a more - * processed way. Think at sets intersections in a tmp key, with an expire so - * that it is also used as a cache to avoid intersecting every time. - * - * This implementation is currently not perfect but a lot better than leaking - * the keys as implemented in 3.2. - *----------------------------------------------------------------------------*/ - -/* The dictionary where we remember key names and database ID of keys we may - * want to expire from the slave. Since this function is not often used we - * don't even care to initialize the database at startup. We'll do it once - * the feature is used the first time, that is, when rememberSlaveKeyWithExpire() - * is called. - * - * The dictionary has an SDS string representing the key as the hash table - * key, while the value is a 64 bit unsigned integer with the bits corresponding - * to the DB where the keys may exist set to 1. Currently the keys created - * with a DB id > 63 are not expired, but a trivial fix is to set the bitmap - * to the max 64 bit unsigned value when we know there is a key with a DB - * ID greater than 63, and check all the configured DBs in such a case. */ -dict *slaveKeysWithExpire = NULL; - -/* Check the set of keys created by the master with an expire set in order to - * check if they should be evicted. */ -void expireSlaveKeys(void) { - if (slaveKeysWithExpire == NULL || - dictSize(slaveKeysWithExpire) == 0) return; - - int cycles = 0, noexpire = 0; - mstime_t start = mstime(); - while(1) { - dictEntry *de = dictGetRandomKey(slaveKeysWithExpire); - sds keyname = dictGetKey(de); - uint64_t dbids = dictGetUnsignedIntegerVal(de); - uint64_t new_dbids = 0; - - /* Check the key against every database corresponding to the - * bits set in the value bitmap. */ - int dbid = 0; - while(dbids && dbid < server.dbnum) { - if ((dbids & 1) != 0) { - redisDb *db = server.db+dbid; - kvobj *kv = dbFindExpires(db, keyname); - int expired = kv && activeExpireCycleTryExpire(server.db+dbid, kv, start); - - /* If the key was not expired in this DB, we need to set the - * corresponding bit in the new bitmap we set as value. - * At the end of the loop if the bitmap is zero, it means we - * no longer need to keep track of this key. */ - if (kv && !expired) { - noexpire++; - new_dbids |= (uint64_t)1 << dbid; - } - } - dbid++; - dbids >>= 1; - } - - /* Set the new bitmap as value of the key, in the dictionary - * of keys with an expire set directly in the writable slave. Otherwise - * if the bitmap is zero, we no longer need to keep track of it. */ - if (new_dbids) - dictSetUnsignedIntegerVal(de,new_dbids); - else - dictDelete(slaveKeysWithExpire,keyname); - - /* Stop conditions: found 3 keys we can't expire in a row or - * time limit was reached. */ - cycles++; - if (noexpire > 3) break; - if ((cycles % 64) == 0 && mstime()-start > 1) break; - if (dictSize(slaveKeysWithExpire) == 0) break; - } -} - -/* Track keys that received an EXPIRE or similar command in the context - * of a writable slave. */ -void rememberSlaveKeyWithExpire(redisDb *db, sds key) { - if (slaveKeysWithExpire == NULL) { - static dictType dt = { - dictSdsHash, /* hash function */ - NULL, /* key dup */ - NULL, /* val dup */ - dictSdsKeyCompare, /* key compare */ - dictSdsDestructor, /* key destructor */ - NULL, /* val destructor */ - NULL /* allow to expand */ - }; - slaveKeysWithExpire = dictCreate(&dt); - } - if (db->id > 63) return; - - dictEntry *de = dictAddOrFind(slaveKeysWithExpire, key); - /* If the entry was just created, set it to a copy of the SDS string - * representing the key: we don't want to need to take those keys - * in sync with the main DB. The keys will be removed by expireSlaveKeys() - * as it scans to find keys to remove. */ - if (dictGetKey(de) == key) { - dictSetKey(slaveKeysWithExpire, de, sdsdup(key)); - dictSetUnsignedIntegerVal(de,0); - } - - uint64_t dbids = dictGetUnsignedIntegerVal(de); - dbids |= (uint64_t)1 << db->id; - dictSetUnsignedIntegerVal(de,dbids); -} - -/* Return the number of keys we are tracking. */ -size_t getSlaveKeyWithExpireCount(void) { - if (slaveKeysWithExpire == NULL) return 0; - return dictSize(slaveKeysWithExpire); -} - -/* Remove the keys in the hash table. We need to do that when data is - * flushed from the server. We may receive new keys from the master with - * the same name/db and it is no longer a good idea to expire them. - * - * Note: technically we should handle the case of a single DB being flushed - * but it is not worth it since anyway race conditions using the same set - * of key names in a writable slave and in its master will lead to - * inconsistencies. This is just a best-effort thing we do. */ -void flushSlaveKeysWithExpireList(void) { - if (slaveKeysWithExpire) { - dictRelease(slaveKeysWithExpire); - slaveKeysWithExpire = NULL; - } -} - -int checkAlreadyExpired(long long when) { - /* EXPIRE with negative TTL, or EXPIREAT with a timestamp into the past - * should never be executed as a DEL when load the AOF or in the context - * of a slave instance. - * - * Instead we add the already expired key to the database with expire time - * (possibly in the past) and wait for an explicit DEL from the master. */ - if (server.current_client && server.current_client->flags & CLIENT_MASTER) return 0; - return (when <= commandTimeSnapshot() && !server.loading && !server.masterhost); -} - -#define EXPIRE_NX (1<<0) -#define EXPIRE_XX (1<<1) -#define EXPIRE_GT (1<<2) -#define EXPIRE_LT (1<<3) - -/* Parse additional flags of expire commands - * - * Supported flags: - * - NX: set expiry only when the key has no expiry - * - XX: set expiry only when the key has an existing expiry - * - GT: set expiry only when the new expiry is greater than current one - * - LT: set expiry only when the new expiry is less than current one */ -int parseExtendedExpireArgumentsOrReply(client *c, int *flags) { - int nx = 0, xx = 0, gt = 0, lt = 0; - - int j = 3; - while (j < c->argc) { - char *opt = c->argv[j]->ptr; - if (!strcasecmp(opt,"nx")) { - *flags |= EXPIRE_NX; - nx = 1; - } else if (!strcasecmp(opt,"xx")) { - *flags |= EXPIRE_XX; - xx = 1; - } else if (!strcasecmp(opt,"gt")) { - *flags |= EXPIRE_GT; - gt = 1; - } else if (!strcasecmp(opt,"lt")) { - *flags |= EXPIRE_LT; - lt = 1; - } else { - addReplyErrorFormat(c, "Unsupported option %s", opt); - return C_ERR; - } - j++; - } - - if ((nx && xx) || (nx && gt) || (nx && lt)) { - addReplyError(c, "NX and XX, GT or LT options at the same time are not compatible"); - return C_ERR; - } - - if (gt && lt) { - addReplyError(c, "GT and LT options at the same time are not compatible"); - return C_ERR; - } - - return C_OK; -} - -/*----------------------------------------------------------------------------- - * Expires Commands - *----------------------------------------------------------------------------*/ - -/* This is the generic command implementation for EXPIRE, PEXPIRE, EXPIREAT - * and PEXPIREAT. Because the command second argument may be relative or absolute - * the "basetime" argument is used to signal what the base time is (either 0 - * for *AT variants of the command, or the current time for relative expires). - * - * unit is either UNIT_SECONDS or UNIT_MILLISECONDS, and is only used for - * the argv[2] parameter. The basetime is always specified in milliseconds. - * - * Additional flags are supported and parsed via parseExtendedExpireArguments */ -void expireGenericCommand(client *c, long long basetime, int unit) { - robj *key = c->argv[1], *param = c->argv[2]; - long long when; /* unix time in milliseconds when the key will expire. */ - long long current_expire = -1; - int flag = 0; - - /* checking optional flags */ - if (parseExtendedExpireArgumentsOrReply(c, &flag) != C_OK) { - return; - } - - if (getLongLongFromObjectOrReply(c, param, &when, NULL) != C_OK) - return; - - /* EXPIRE allows negative numbers, but we can at least detect an - * overflow by either unit conversion or basetime addition. */ - if (unit == UNIT_SECONDS) { - if (when > LLONG_MAX / 1000 || when < LLONG_MIN / 1000) { - addReplyErrorExpireTime(c); - return; - } - when *= 1000; - } - - if (when > LLONG_MAX - basetime) { - addReplyErrorExpireTime(c); - return; - } - when += basetime; - - /* No key, return zero. */ - kvobj *kv = lookupKeyWrite(c->db,key); - if (kv == NULL) { - addReply(c,shared.czero); - return; - } - - if (flag) { - current_expire = kvobjGetExpire(kv); - - /* NX option is set, check current expiry */ - if (flag & EXPIRE_NX) { - if (current_expire != -1) { - addReply(c,shared.czero); - return; - } - } - - /* XX option is set, check current expiry */ - if (flag & EXPIRE_XX) { - if (current_expire == -1) { - /* reply 0 when the key has no expiry */ - addReply(c,shared.czero); - return; - } - } - - /* GT option is set, check current expiry */ - if (flag & EXPIRE_GT) { - /* When current_expire is -1, we consider it as infinite TTL, - * so expire command with gt always fail the GT. */ - if (when <= current_expire || current_expire == -1) { - /* reply 0 when the new expiry is not greater than current */ - addReply(c,shared.czero); - return; - } - } - - /* LT option is set, check current expiry */ - if (flag & EXPIRE_LT) { - /* When current_expire -1, we consider it as infinite TTL, - * but 'when' can still be negative at this point, so if there is - * an expiry on the key and it's not less than current, we fail the LT. */ - if (current_expire != -1 && when >= current_expire) { - /* reply 0 when the new expiry is not less than current */ - addReply(c,shared.czero); - return; - } - } - } - - if (checkAlreadyExpired(when)) { - robj *aux; - - int deleted = dbGenericDelete(c->db,key,server.lazyfree_lazy_expire,DB_FLAG_KEY_EXPIRED); - serverAssertWithInfo(c,key,deleted); - server.dirty++; - - /* Replicate/AOF this as an explicit DEL or UNLINK. */ - aux = server.lazyfree_lazy_expire ? shared.unlink : shared.del; - rewriteClientCommandVector(c,2,aux,key); - keyModified(c,c->db,key,NULL,1); - notifyKeyspaceEvent(NOTIFY_GENERIC,"del",key,c->db->id); - addReply(c, shared.cone); - return; - } else { - kv = setExpire(c,c->db,key,when); /* might realloc kv */ - addReply(c,shared.cone); - /* Propagate as PEXPIREAT millisecond-timestamp - * Only rewrite the command arg if not already PEXPIREAT */ - if (c->cmd->proc != pexpireatCommand) { - rewriteClientCommandArgument(c,0,shared.pexpireat); - } - - /* Avoid creating a string object when it's the same as argv[2] parameter */ - if (basetime != 0 || unit == UNIT_SECONDS) { - robj *when_obj = createStringObjectFromLongLong(when); - rewriteClientCommandArgument(c,2,when_obj); - decrRefCount(when_obj); - } - - keyModified(c,c->db,key,kv,1); - notifyKeyspaceEvent(NOTIFY_GENERIC,"expire",key,c->db->id); - server.dirty++; - return; - } -} - -/* EXPIRE key seconds [ NX | XX | GT | LT] */ -void expireCommand(client *c) { - expireGenericCommand(c,commandTimeSnapshot(),UNIT_SECONDS); -} - -/* EXPIREAT key unix-time-seconds [ NX | XX | GT | LT] */ -void expireatCommand(client *c) { - expireGenericCommand(c,0,UNIT_SECONDS); -} - -/* PEXPIRE key milliseconds [ NX | XX | GT | LT] */ -void pexpireCommand(client *c) { - expireGenericCommand(c,commandTimeSnapshot(),UNIT_MILLISECONDS); -} - -/* PEXPIREAT key unix-time-milliseconds [ NX | XX | GT | LT] */ -void pexpireatCommand(client *c) { - expireGenericCommand(c,0,UNIT_MILLISECONDS); -} - -/* Implements TTL, PTTL, EXPIRETIME and PEXPIRETIME */ -void ttlGenericCommand(client *c, int output_ms, int output_abs) { - long long expire, ttl = -1; - - /* If the key does not exist at all, return -2 */ - kvobj *kv = lookupKeyReadWithFlags(c->db,c->argv[1],LOOKUP_NOTOUCH); - if (kv == NULL) { - addReplyLongLong(c,-2); - return; - } - - /* The key exists. Return -1 if it has no expire, or the actual - * TTL value otherwise. */ - expire = kvobjGetExpire(kv); - if (expire != -1) { - ttl = output_abs ? expire : expire-commandTimeSnapshot(); - if (ttl < 0) ttl = 0; - } - if (ttl == -1) { - addReplyLongLong(c,-1); - } else { - addReplyLongLong(c,output_ms ? ttl : ((ttl+500)/1000)); - } -} - -/* TTL key */ -void ttlCommand(client *c) { - ttlGenericCommand(c, 0, 0); -} - -/* PTTL key */ -void pttlCommand(client *c) { - ttlGenericCommand(c, 1, 0); -} - -/* EXPIRETIME key */ -void expiretimeCommand(client *c) { - ttlGenericCommand(c, 0, 1); -} - -/* PEXPIRETIME key */ -void pexpiretimeCommand(client *c) { - ttlGenericCommand(c, 1, 1); -} - -/* PERSIST key */ -void persistCommand(client *c) { - kvobj *kv; - if ((kv = lookupKeyWrite(c->db,c->argv[1]))) { - if (removeExpire(c->db,c->argv[1])) { - keyModified(c,c->db,c->argv[1],kv,1); - notifyKeyspaceEvent(NOTIFY_GENERIC,"persist",c->argv[1],c->db->id); - addReply(c,shared.cone); - server.dirty++; - } else { - addReply(c,shared.czero); - } - } else { - addReply(c,shared.czero); - } -} - -/* TOUCH key1 [key2 key3 ... keyN] */ -void touchCommand(client *c) { - int touched = 0; - for (int j = 1; j < c->argc; j++) - if (lookupKeyRead(c->db,c->argv[j]) != NULL) touched++; - addReplyLongLong(c,touched); -} |