Key management commands allow you to inspect, delete, and manage keys across your ValKeyper instance.
DEL
Removes the specified key. A key is ignored if it does not exist. If the key has an associated expiry timer, it is also cancelled.
Syntax
Parameters
Return Value
Integer reply:
1 if the key was removed0 if the key does not exist
Examples
# Set and delete a key
SET mykey "Hello"
DEL mykey
# Response: 1
# Try to delete a non-existent key
DEL nonexistent
# Response: 0
# Delete a key with expiry
SET tempkey "value" PX 10000
DEL tempkey
# Response: 1
# The expiry timer is also cancelled
Implementation Details
From store.go:193-208:
case "DEL":
key := buff[1]
_, ok := kv.store[key]
if !ok {
res = []byte(":0\r\n")
break switchLoop
}
delete(kv.store, key)
ch, ok := kv.expiryMap[key]
if ok {
ch <- 1 // Cancel the expiry goroutine
}
res = []byte(":1\r\n")
KEYS
Returns all keys currently stored in the database. In this implementation, it returns all keys regardless of the pattern argument.
Syntax
Parameters
Pattern to match keys against. In the current implementation, this parameter is accepted but all keys are returned.
Return Value
Array reply: List of keys in the database.
Examples
# Set multiple keys
SET key1 "value1"
SET key2 "value2"
SET key3 "value3"
# Get all keys
KEYS *
# Response:
# 1) "key1"
# 2) "key2"
# 3) "key3"
# Empty database
DEL key1
DEL key2
DEL key3
KEYS *
# Response: (empty array)
Implementation Details
From store.go:240-246:
case "KEYS":
keys := []string{}
for k := range kv.store {
keys = append(keys, k)
}
res = resp.ToArray(keys)
The KEYS command should be used with caution in production environments with large datasets, as it iterates through all keys and can impact performance.
TYPE
Returns the data type of the value stored at the specified key.
Syntax
Parameters
Return Value
Simple string reply:
string - The key holds a string valuestream - The key holds a streamnone - The key does not exist
Examples
# Check type of a string key
SET mykey "Hello"
TYPE mykey
# Response: string
# Check type of a stream
XADD mystream * field1 value1
TYPE mystream
# Response: stream
# Check type of non-existent key
TYPE nonexistent
# Response: none
Implementation Details
From store.go:305-316:
case "TYPE":
_, ok := kv.store[buff[1]]
if ok {
res = []byte("+string\r\n")
} else {
_, ok2 := kv.Stream[buff[1]]
if ok2 {
res = []byte("+stream\r\n")
} else {
res = []byte("+none\r\n")
}
}
EXPIRE (via SET)
While ValKeyper doesn’t have a standalone EXPIRE command, you can set expiration times when creating keys using the SET command with the PX option.
Syntax
SET key value PX milliseconds
Parameters
The key to set with expiration
Time to live in milliseconds
Examples
# Set a key that expires in 5 seconds
SET session "active" PX 5000
GET session
# Response: "active"
# Wait 6 seconds
GET session
# Response: (nil)
Implementation Details
From store.go:53-62:
func (kv *KVStore) Set(key, value string, expiry int) {
if expiry != -1 {
timeout := time.After(time.Duration(expiry) * time.Millisecond)
go kv.handleExpiry(timeout, key)
}
kv.store[key] = value
}
handleExpiry function (lines 94-105) manages a goroutine that waits for either:
- The timeout to expire, which deletes the key
- A cancellation signal (when the key is deleted manually)
Use Cases
Database Cleanup
# Remove temporary data
SET temp:processing "data"
DEL temp:processing
Key Discovery
# Find all keys in the database
KEYS *
# Inspect each key type
TYPE user:123
TYPE stream:events
Session Management
# Create session with auto-expiry
SET session:abc123 "{\"user\": \"john\"}" PX 1800000 # 30 minutes
# Manually end session
DEL session:abc123
Type Checking
# Verify data type before operations
TYPE mycounter
# Response: string
INCR mycounter # Safe to increment
TYPE mystream
# Response: stream
XRANGE mystream - + # Safe to read stream
