sysfiles/usr/local/jilits/libstate.sh

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2022-11-27 21:30:10 +01:00
#!/bin/bash
# Make sure the state directory exists and create it if not
ensure_state_dir() {
local state_dir="${STATE_DIR:?}"
if ! [ -d "$(dirname "$state_dir")" ]; then
errlog "ERROR: Parent directory of STATE_DIR '$state_dir' doesn't exist."
return 1
elif ! [ -d "$state_dir" ]; then
if ! mkdir "$state_dir"; then
errlog "ERROR: Failed to create STATE_DIR '$state_dir'."
return 2
fi
fi
}
# Get the configured TTL for a state key
get_state_ttl() {
local state_file="${1:?Missing state file}"
local ttl_file="$state_file.ttl"
local state_ttl
state_ttl="$(cat "$ttl_file" 2>/dev/null)"
if ! is_int "$state_ttl"; then
errlog "WARN: Invalid value '$state_ttl' in '$ttl_file'. Assuming value 0."
state_ttl=0
fi
echo "$state_ttl"
}
# Get the age of a state key
get_state_age() {
local state_file="${1:?Missing state file}"
local state_mod
state_mod="$(stat -c%Y "$state_file")"
echo "$(($(current_ue) - state_mod))"
}
# Check if a state has expired
state_is_expired() {
local state_file="${1:?Missing state file}"
local state_ttl state_mod
state_ttl="$(get_state_ttl "$state_file")"
[ "$state_ttl" -eq 0 ] && return 1
[ "$(get_state_age "$state_file")" -gt "$state_ttl" ] && return 0
}
# Remove a state
rm_state() {
local key="${1:?Missing key}"
local state_file="$STATE_DIR/$key"
local ttl_file="$state_file.ttl"
rm "$state_file" "$ttl_file"
}
# Check if a state key name is valid
state_key_is_valid() {
local key="${1:?Missing key}" regex="^([0-9]|[a-z]|[A-Z]|-)*$"
if ! [[ "$key" =~ $regex ]]; then
errlog "ERROR: Key '$key' doesn't match regex '$regex'."
return 1
fi
}
# Write a value to a state key and optionally set a TTL
set_state() {
local key="${1:?Missing key}" value="$2" ttl="${3:-0}"
local state_file="$STATE_DIR/$key"
local ttl_file="$state_file.ttl"
state_key_is_valid "$key" || return 1
ensure_state_dir || return 2
echo "$value" >"$state_file"
echo "$ttl" >"$ttl_file"
}
# Read a value from a state key
get_state() {
local key="${1:?Missing key}"
local state_file="$STATE_DIR/$key"
state_key_is_valid "$key" || return 1
ensure_state_dir || return 2
if ! [ -f "$state_file" ]; then
errlog "WARN: State file doesn't exist: '$state_file'"
return 3
elif state_is_expired "$state_file"; then
errlog "WARN: State file has expired: '$state_file'"
rm_state "$key"
return 4
fi
cat "$state_file"
}