timbre/src/taoensso/timbre.clj

455 lines
16 KiB
Clojure

(ns taoensso.timbre
"Simple, flexible, all-Clojure logging. No XML!"
{:author "Peter Taoussanis"}
(:require [clojure.string :as str]
[clj-stacktrace.repl :as stacktrace]
[taoensso.timbre.utils :as utils])
(:import [java.util Date Locale]
[java.text SimpleDateFormat]))
;;;; Public utils
(defn str-println
"Like `println` but prints all objects to output stream as a single
atomic string. This is faster and avoids interleaving race conditions."
[& xs]
(print (str/join \space (filter identity xs)) \newline)
(flush))
(defn color-str [color & xs]
(let [ansi-color #(str "\u001b[" (case % :reset "0" :black "30" :red "31"
:green "32" :yellow "33" :blue "34"
:purple "35" :cyan "36" :white "37"
"0") "m")]
(str (ansi-color color) (apply str xs) (ansi-color :reset))))
(def red (partial color-str :red))
(def green (partial color-str :green))
(def yellow (partial color-str :yellow))
(def default-out (java.io.OutputStreamWriter. System/out))
(def default-err (java.io.PrintWriter. System/err))
(defmacro with-default-outs
"Evaluates body with Clojure's default *out* and *err* bindings."
[& body] `(binding [*out* default-out *err* default-err] ~@body))
(defmacro with-err-as-out
"Evaluates body with *err* bound to *out*."
[& body] `(binding [*err* *out*] ~@body))
(defn stacktrace [throwable & [separator]]
(when throwable
(str separator throwable ; (str throwable) incl. ex-data for Clojure 1.4+
"\n\n" (stacktrace/pst-str throwable))))
;;;; Default configuration and appenders
(def ^:dynamic *current-level* nil)
(defmacro with-log-level
"Allows thread-local config logging level override. Useful for dev & testing."
[level & body] `(binding [*current-level* ~level] ~@body))
(utils/defonce* config
"This map atom controls everything about the way Timbre operates.
APPENDERS
An appender is a map with keys:
:doc, :min-level, :enabled?, :async?, :limit-per-msecs, :fn
An appender's fn takes a single map argument with keys:
:level, :throwable
:message, ; Stringified logging macro args, or nil
:args, ; Raw logging macro args (`info`, etc.)
:ap-config ; `shared-appender-config`
:prefix ; Output of `prefix-fn`
:profiling-stats ; From `profile` macro
And also: :instant, :timestamp, :hostname, :ns, :error?
MIDDLEWARE
Middleware are fns (applied right-to-left) that transform the map argument
dispatched to appender fns. If any middleware returns nil, no dispatching
will occur (i.e. the event will be filtered).
See source code for examples. See `set-config!`, `merge-config!`, `set-level!`
for convenient config editing."
(atom {:current-level :debug ; See also `with-log-level`
;;; Control log filtering by namespace patterns (e.g. ["my-app.*"]).
;;; Useful for turning off logging in noisy libraries, etc.
:ns-whitelist []
:ns-blacklist []
;; Fns (applied right-to-left) to transform/filter appender fn args.
;; Useful for obfuscating credentials, pattern filtering, etc.
:middleware []
;;; Control :timestamp format
:timestamp-pattern "yyyy-MMM-dd HH:mm:ss ZZ" ; SimpleDateFormat pattern
:timestamp-locale nil ; A Locale object, or nil
;; Control :prefix format
:prefix-fn
(fn [{:keys [level timestamp hostname ns]}]
(str timestamp " " hostname " " (-> level name str/upper-case)
" [" ns "]"))
;; Will be provided to all appenders via :ap-config key
:shared-appender-config {}
:appenders
{:standard-out
{:doc "Prints to *out* or *err* as appropriate. Enabled by default."
:min-level nil :enabled? true :async? false :limit-per-msecs nil
:fn (fn [{:keys [error? prefix throwable message]}]
(binding [*out* (if error? *err* *out*)]
(str-println prefix "-" message (stacktrace throwable))))}
:spit
{:doc "Spits to (:spit-filename :shared-appender-config) file."
:min-level nil :enabled? false :async? false :limit-per-msecs nil
:fn (fn [{:keys [ap-config prefix throwable message]}]
(when-let [filename (:spit-filename ap-config)]
(try (spit filename
(with-out-str
(str-println prefix "-" message
(stacktrace throwable)))
:append true)
(catch java.io.IOException _))))}}}))
(defn set-config! [ks val] (swap! config assoc-in ks val))
(defn merge-config! [& maps] (apply swap! config utils/merge-deep maps))
(defn set-level! [level] (set-config! [:current-level] level))
;;;; Define and sort logging levels
(def ^:private ordered-levels [:trace :debug :info :warn :error :fatal :report])
(def ^:private scored-levels (assoc (zipmap ordered-levels (next (range))) nil 0))
(defn error-level? [level] (boolean (#{:error :fatal} level)))
(defn- checked-level-score [level]
(or (scored-levels level)
(throw (Exception. (str "Invalid logging level: " level)))))
(def compare-levels
(memoize (fn [x y] (- (checked-level-score x) (checked-level-score y)))))
(defn sufficient-level?
[level] (>= (compare-levels level (or *current-level* (:current-level @config))) 0))
;;;; Appender-fn decoration
(defn- wrap-appender-fn
"Wraps compile-time appender fn with additional runtime capabilities
controlled by compile-time config."
[{apfn :fn :keys [async? limit-per-msecs prefix-fn] :as appender}]
(let [limit-per-msecs (or (:max-message-per-msecs appender)
limit-per-msecs)] ; Backwards-compatibility
(->> ; Wrapping applies per appender, bottom-to-top
apfn
;; Per-appender prefix-fn support (cmp. default prefix-fn)
;; TODO Currently undocumented, candidate for removal
((fn [apfn]
(if-not prefix-fn
apfn
(fn [apfn-args]
(apfn (assoc apfn-args
:prefix (prefix-fn apfn-args)))))))
;; Rate limit support
((fn [apfn]
(if-not limit-per-msecs
apfn
(let [timers (atom {})] ; {:hash last-appended-time-msecs ...}
(fn [{ns :ns [x1 & _] :args :as apfn-args}]
(let [now (System/currentTimeMillis)
hash (str ns "/" x1)
limit? (fn [last-msecs]
(and last-msecs (<= (- now last-msecs)
limit-per-msecs)))]
(when-not (limit? (@timers hash))
(apfn apfn-args)
(swap! timers assoc hash now))
(when (< (rand) 0.001) ; Occasionally garbage collect
(when-let [expired-timers (->> (keys @timers)
(remove #(limit? (@timers %)))
(seq))]
(apply swap! timers dissoc expired-timers)))))))))
;; Async (agent) support
((fn [apfn]
(if-not async?
apfn
(let [agent (agent nil :error-mode :continue)]
(fn [apfn-args] (send-off agent (fn [_] (apfn apfn-args)))))))))))
(defn- make-timestamp-fn
"Returns a unary fn that formats instants using given pattern string and an
optional Locale."
[^String pattern ^Locale locale]
(let [format (if locale
(SimpleDateFormat. pattern locale)
(SimpleDateFormat. pattern))]
(fn [^Date instant] (.format ^SimpleDateFormat format instant))))
(comment ((make-timestamp-fn "yyyy-MMM-dd" nil) (Date.)))
(def get-hostname
(utils/memoize-ttl
60000 (fn [] (try (.. java.net.InetAddress getLocalHost getHostName)
(catch java.net.UnknownHostException _
"UnknownHost")))))
(defn- wrap-appender-juxt
"Wraps compile-time appender juxt with additional runtime capabilities
(incl. middleware) controlled by compile-time config. Like `wrap-appender-fn`
but operates on the entire juxt at once."
[juxtfn]
(->> ; Wrapping applies per juxt, bottom-to-top
juxtfn
;; Middleware transforms/filters support
((fn [juxtfn]
(if-let [middleware (seq (:middleware @config))]
(let [composed-middleware
(apply comp (map (fn [mf] (fn [args] (when args (mf args))))
middleware))]
(fn [juxtfn-args]
(when-let [juxtfn-args (composed-middleware juxtfn-args)]
(juxtfn juxtfn-args))))
juxtfn)))
;; Add compile-time stuff to runtime appender args
((fn [juxtfn]
(let [{ap-config :shared-appender-config
:keys [timestamp-pattern timestamp-locale prefix-fn]} @config
timestamp-fn (make-timestamp-fn timestamp-pattern timestamp-locale)]
(fn [{:keys [instant] :as juxtfn-args}]
(let [juxtfn-args (merge juxtfn-args {:ap-config ap-config
:timestamp (timestamp-fn instant)
:hostname (get-hostname)})]
(juxtfn (assoc juxtfn-args :prefix (prefix-fn juxtfn-args))))))))))
;;;; Caching
;;; Appender-fns
(def appenders-juxt-cache
"Per-level, combined level-relevant appender-fns to allow for fast runtime
appender-fn dispatch:
{:level (wrapped-juxt wrapped-appender-fn wrapped-appender-fn ...) or nil
...}"
(atom {}))
(defn- relevant-appenders [level]
(->> (:appenders @config)
(filter #(let [{:keys [enabled? min-level]} (val %)]
(and enabled? (>= (compare-levels level min-level) 0))))
(into {})))
(comment (relevant-appenders :debug)
(relevant-appenders :trace))
(defn- cache-appenders-juxt! []
(->>
(zipmap
ordered-levels
(->> ordered-levels
(map (fn [l] (let [rel-aps (relevant-appenders l)]
;; Return nil if no relevant appenders
(when-let [ap-ids (keys rel-aps)]
(->> ap-ids
(map #(wrap-appender-fn (rel-aps %)))
(apply juxt)
(wrap-appender-juxt))))))))
(reset! appenders-juxt-cache)))
;;; Namespace filter
(def ns-filter-cache "@ns-filter-cache => (fn relevant-ns? [ns] ...)"
(atom (constantly true)))
(defn- ns-match? [ns match]
(-> (str "^" (-> (str match) (.replace "." "\\.") (.replace "*" "(.*)")) "$")
re-pattern (re-find (str ns)) boolean))
(defn- cache-ns-filter! []
(->>
(let [{:keys [ns-whitelist ns-blacklist]} @config]
(memoize
(fn relevant-ns? [ns]
(and (or (empty? ns-whitelist)
(some (partial ns-match? ns) ns-whitelist))
(or (empty? ns-blacklist)
(not-any? (partial ns-match? ns) ns-blacklist))))))
(reset! ns-filter-cache)))
;;; Prime initial caches and re-cache on config change
(cache-appenders-juxt!)
(cache-ns-filter!)
(add-watch
config "config-cache-watch"
(fn [key ref old-state new-state]
(when (not= (dissoc old-state :current-level)
(dissoc new-state :current-level))
(cache-appenders-juxt!)
(cache-ns-filter!))))
;;;; Define logging macros
(defn logging-enabled?
"Returns true when current logging level is sufficient and current namespace
is unfiltered."
[level] (and (sufficient-level? level) (@ns-filter-cache *ns*)))
(defmacro log*
"Implementation detail - subject to change..
Prepares given arguments for, and then dispatches to all level-relevant
appender-fns. "
;; For tools.logging.impl/Logger support
([base-appender-args level log-vargs ns throwable message juxt-fn]
`(when-let [juxt-fn# (or ~juxt-fn (@appenders-juxt-cache ~level))]
(juxt-fn#
(conj (or ~base-appender-args {})
{:instant (Date.)
:ns ~ns
:level ~level
:error? (error-level? ~level)
:args ~log-vargs ; No native tools.logging support
:throwable ~throwable
:message ~message}))
nil))
([base-appender-args level log-args message-fn]
`(when-let [juxt-fn# (@appenders-juxt-cache ~level)]
(let [[x1# & xn# :as xs#] (vector ~@log-args)
has-throwable?# (instance? Throwable x1#)
log-vargs# (vec (if has-throwable?# xn# xs#))]
(log* ~base-appender-args
~level
log-vargs#
~(str *ns*)
(when has-throwable?# x1#)
(when-let [mf# ~message-fn]
(when-not (empty? log-vargs#)
(apply mf# log-vargs#)))
juxt-fn#)))))
(defmacro log
"When logging is enabled, actually logs given arguments with level-relevant
appender-fns using print-style :message."
{:arglists '([level & message] [level throwable & message])}
[level & sigs]
`(when (logging-enabled? ~level)
(log* {} ~level ~sigs print-str)))
(defmacro logf
"When logging is enabled, actually logs given arguments with level-relevant
appender-fns using format-style :message."
{:arglists '([level fmt & fmt-args] [level throwable fmt & fmt-args])}
[level & sigs]
`(when (logging-enabled? ~level)
(log* {} ~level ~sigs format)))
(defmacro log-errors [& body] `(try ~@body (catch Throwable t# (error t#))))
(defmacro log-and-rethrow-errors [& body]
`(try ~@body (catch Throwable t# (error t#) (throw t#))))
(defmacro logged-future [& body] `(future (log-errors ~@body)))
(comment (log-errors (/ 0))
(log-and-rethrow-errors (/ 0))
(logged-future (/ 0)))
(defmacro spy
"Evaluates named expression and logs its result. Always returns the result.
Defaults to :debug logging level and unevaluated expression as name."
([expr] `(spy :debug ~expr))
([level expr] `(spy ~level '~expr ~expr))
([level name expr]
`(log-and-rethrow-errors
(let [result# ~expr] (log ~level ~name result#) result#))))
(defmacro ^:private def-logger [level]
(let [level-name (name level)]
`(do
(defmacro ~(symbol level-name)
~(str "Log given arguments at " level " level using print-style args.")
~'{:arglists '([& message] [throwable & message])}
[& sigs#] `(log ~~level ~@sigs#))
(defmacro ~(symbol (str level-name "f"))
~(str "Log given arguments at " level " level using format-style args.")
~'{:arglists '([fmt & fmt-args] [throwable fmt & fmt-args])}
[& sigs#] `(logf ~~level ~@sigs#)))))
(defmacro ^:private def-loggers []
`(do ~@(map (fn [level] `(def-logger ~level)) ordered-levels)))
(def-loggers) ; Actually define a logger for each logging level
(defn refer-timbre
"Shorthand for:
(require '[taoensso.timbre :as timbre
:refer (trace debug info warn error fatal report spy with-log-level)])"
[]
(require '[taoensso.timbre :as timbre
:refer (trace debug info warn error fatal report spy with-log-level)]))
;;;; Deprecated
(defmacro logp "DEPRECATED: Use `log` instead."
{:arglists '([level & message] [level throwable & message])}
[& sigs] `(log ~@sigs)) ; Alias
(defmacro s "DEPRECATED: Use `spy` instead."
{:arglists '([expr] [level expr] [level name expr])}
[& args] `(spy ~@args))
;;;; Dev/tests
(comment
(info)
(info "a")
(info "a" "b" "c")
(info "a" (Exception. "b") "c")
(info (Exception. "a") "b" "c")
(log (or nil :info) "Booya")
(info "a%s" "b")
(infof "a%s" "b")
(set-config! [:ns-blacklist] [])
(set-config! [:ns-blacklist] ["taoensso.timbre*"])
(info "foo" "bar")
(trace (Thread/sleep 5000))
(time (dotimes [n 10000] (trace "This won't log"))) ; Overhead 5ms/10ms
(time (dotimes [n 5] (info "foo" "bar")))
(spy (* 6 5 4 3 2 1))
(spy :debug :factorial6 (* 6 5 4 3 2 1))
(info (Exception. "noes!") "bar")
(spy (/ 4 0))
(with-log-level :trace (trace "foo"))
(with-log-level :debug (trace "foo"))
;; Middleware
(info {:name "Robert Paulson" :password "Super secret"})
(set-config!
[:middleware]
[(fn [{:keys [hostname message] :as args}]
(cond (= hostname "filtered-host") nil ; Filter
(map? message)
(if (contains? message :password)
(assoc args :message (assoc message :password "*****"))
args)
:else args))]))