apps/rophako
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Continue functioning even if Redis is down

Browse Source
This commit is contained in:
Noah 2014-12-23 15:55:48 -08:00
parent 364c334b98
commit a69e013fb5
1 changed files with 31 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

43
rophako/jsondb.py
View File

@ -187,23 +187,35 @@ def write_json(path, data):
# Redis Caching Functions # # Redis Caching Functions #
############################################################################ ############################################################################
disable_redis = False
def get_redis(): def get_redis():
"""Connect to Redis or return the existing connection.""" """Connect to Redis or return the existing connection."""
global redis_client global redis_client
if not redis_client: global disable_redis
redis_client = redis.StrictRedis(
host = Config.db.redis_host, if not redis_client and not disable_redis:
port = Config.db.redis_port, try:
db = Config.db.redis_db, redis_client = redis.StrictRedis(
) host = Config.db.redis_host,
port = Config.db.redis_port,
db = Config.db.redis_db,
)
redis_client.ping()
except Exception as e:
logger.error("Couldn't connect to Redis; memory caching will be disabled! {}".format(e.message))
redis_client = None
disable_redis = True
return redis_client return redis_client
def set_cache(key, value, expires=None): def set_cache(key, value, expires=None):
"""Set a key in the Redis cache.""" """Set a key in the Redis cache."""
key = Config.db.redis_prefix + key key = Config.db.redis_prefix + key
client = get_redis()
if not client:
return
try: try:
client = get_redis()
client.set(key, json.dumps(value)) client.set(key, json.dumps(value))
# Expiration date? # Expiration date?
@ -217,8 +229,11 @@ def get_cache(key):
"""Get a cached item.""" """Get a cached item."""
key = Config.db.redis_prefix + key key = Config.db.redis_prefix + key
value = None value = None
client = get_redis()
if not client:
return
try: try:
client = get_redis()
value = client.get(key) value = client.get(key)
if value: if value:
value = json.loads(value) value = json.loads(value)
@ -232,6 +247,8 @@ def del_cache(key):
"""Delete a cached item.""" """Delete a cached item."""
key = Config.db.redis_prefix + key key = Config.db.redis_prefix + key
client = get_redis() client = get_redis()
if not client:
return
client.delete(key) client.delete(key)
@ -243,8 +260,9 @@ def lock_cache(key, timeout=5, expire=20):
The `expire` is how long a lock may exist before it's considered stale. The `expire` is how long a lock may exist before it's considered stale.
Returns True on success, None on failure to acquire lock.""" Returns True on success, None on failure to acquire lock."""
lock_key = key + "_lock" client = get_redis()
client = get_redis() if not client:
return
# Take the lock. # Take the lock.
lock = client.lock(key, timeout=expire) lock = client.lock(key, timeout=expire)
@ -255,5 +273,6 @@ def lock_cache(key, timeout=5, expire=20):
def unlock_cache(lock): def unlock_cache(lock):
"""Release the lock on a cache key.""" """Release the lock on a cache key."""
lock.release() if lock:
logger.debug("Cache lock released") lock.release()
logger.debug("Cache lock released")