taoensso.tufte — com.taoensso/tufte 2.4.1

A simple, fast, monitoring profiler for Clojure/Script.

Usage: wrap+name interesting body exprs with the p macro. Then activate profiling of these wrapped exprs using the profiled or profile macros:

(profiled {} (p :my-fn (my-fn))) ; Returns [<body-result> <?pstats>] (profile {} (p :my-fn (my-fn))) ; Returns <body-result>, dispatches ; ?pstats to any registered handlers.

Extensive facilities are provided for compile-time elision and runtime filtering.

See the relevant docstrings for more info: p, profiled, profile, add-handler! ; Core API

(p [opts & body] [id & body]) ; e.g. (p ::my-pid (do-work)) (profiled [opts & body]) ; e.g. (profiled {:level 2} (my-fn)) (profile [opts & body]) ; e.g. (profiled {:level 2} (my-fn))

(add-handler! [handler-id ns-pattern handler-fn])

How/where to use this library: Tufte profiling is highly optimized: even without elision, you can usually leave profiling enabled in production (e.g. for sampled profiling, or to detect unusual performance behaviour). Tufte's stats maps are well suited to programmatic monitoring.

Abbreviations, etc.

• form id = pid = id given in p
• group id = gid = id given in profile

*min-level* clj/s

Integer e/o #{0 1 2 3 4 5 6}, or vector mapping ns-patterns to min-levels: [[<ns-pattern> <min-level>] ... ["*" <default-min-level>]]

See *ns-filter* for example patterns.

*ns-filter* clj/s

(fn may-profile-ns? [ns]) predicate, or ns-pattern. Example ns-patterns: #{}, "", "foo.bar", "foo.bar.", #{"foo" "bar."}, {:allow #{"foo" "bar."} :deny #{"foo..bar."}}

-elide? clj

(-elide? level-form ns-str-form)

Returns true iff level or ns are compile-time filtered. Called only at macro-expansiom time.

add-accumulating-handler! clj/s

(add-accumulating-handler! {:keys [ns-pattern handler-id]
                            :or {ns-pattern "*" handler-id :accumulating}})

Alpha, subject to change.

Creates a new StatsAccumulator (and agent in clj), then registers a handler to accumulate profile output to the StatsAccumulator using the agent.

Returns the StatsAccumulator. You can deref the result to drain the accumulator and return {<group-id> <merged-pstats>}.

One common pattern is to deref the accumulator every n minutes/etc. to get a view of total-system performance over the period, e.g.:

(defonce my-sacc (add-accumulating-handler! {:ns-pattern "*"})) (defonce my-sacc-drainer ;; Will drain and print formatted stats every minute (future (while true (when-let [m (not-empty @my-sacc)] (println (format-grouped-pstats m))) (Thread/sleep 60000))))

(profile ...) ; Used elsewhere in your application, e.g. ; wrapping relevant Ring routes in a web application.

See also format-grouped-pstats, example clj project.

add-basic-println-handler! clj/s

(add-basic-println-handler! {:keys [ns-pattern handler-id format-pstats-opts]
                             :or {ns-pattern "*" handler-id :basic-println}})

Adds a simple handler that logs profile stats output with println.

add-handler! clj/s

(add-handler! handler-id handler-fn)

(add-handler! handler-id ns-pattern handler-fn)

Use this to register interest in stats output produced by profile calls. Each registered handler-fn will be called as:

(handler-fn {:ns-str _ :level _ :?id _ :?data _ :pstats _ :pstats-str_ _})

Map args: :ns-str - Namespace string where profile call took place :level - Level e/o #{0 1 2 3 4 5}, given in (profile {:level _} ...) :?id - Optional group id, given in (profile {:id _} ...) :?data - Optional arb data, given in (profile {:data _} ...) :pstats - As in (second (profiled ...)). Derefable, mergeable. :pstats-str_ - `(delay (format-pstats pstats))

Error handling (NB): Handler errors will be silently swallowed. Please try/catch and appropriately deal with (e.g. log) possible errors within handler-fn.

Async/blocking: handler-fn should ideally be non-blocking, or reasonably cheap. Handler dispatch occurs through a 1-thread 1k-buffer dropping queue.

Ns filtering: Provide an optional ns-pattern arg to only call handler for matching namespaces. See *ns-filter* for example patterns.

Handler ideas: Save to a db, log, put! to an appropriate core.async channel, filter, aggregate, use for a realtime analytics dashboard, examine for outliers or unexpected output, ...

capture-time! clj/s

(capture-time! id nano-secs-elapsed)

(capture-time! pdata id nano-secs-elapsed)

Note: this is a low-level primitive for advanced users! Can be useful when tracking time across arbitrary thread boundaries or for async jobs / callbacks / etc.

See new-pdata for more info on low-level primitives.

chance clj/s

(chance p)

Returns true with 0<p<1 probability.

compile-ns-filter clj/s

(compile-ns-filter ns-pattern)

Wraps taoensso.encore/compile-str-filter.

defnp clj/s≠ macro

clj

(defnp name doc-string? attr-map? [params*] prepost-map? body)

(defnp name doc-string? attr-map? ([params*] prepost-map? body) + attr-map?)

cljs

(defnp & sigs)

Like defn but wraps fn bodies with p macro.

defnp- clj/s≠ macro

clj

(defnp- name doc-string? attr-map? [params*] prepost-map? body)

(defnp- name doc-string? attr-map? ([params*] prepost-map? body) + attr-map?)

cljs

(defnp- & sigs)

Like defn- but wraps fn bodies with p macro.

fnp clj/s≠ macro

clj

(fnp name? ([params*] prepost-map? body) +)

(fnp name? [params*] prepost-map? body)

cljs

(fnp & sigs)

Like fn but wraps fn bodies with p macro.

format-grouped-pstats clj/s

(format-grouped-pstats m)

(format-grouped-pstats m
                       {:keys [group-sort-fn format-pstats-opts]
                        :or {group-sort-fn (fn [m]
                                               (get-in m [:clock :total] 0))}})

Alpha, subject to change. Takes a map of {<group-id> <PStats>} and formats a combined output string using format-pstats.

See also example clj project.

format-id-abbr clj/s

(format-id-abbr)

(format-id-abbr n)

Returns a cached (fn [id]) -> abbreviated id string. Takes n (default 1), the number of namespace parts to keep unabbreviated.

Examples: ((format-id-abbr) :foo) => "foo" ((format-id-abbr) :example.hello/foo) => "e.hello/foo" ((format-id-abbr 1) :example.hello/foo) => "e.hello/foo" ((format-id-abbr 1) :example.hello.world/foo) => "e.h.world/foo" ((format-id-abbr 2) :example.hello.world/foo) => "e.hello.world/foo" ((format-id-abbr 0) :example.hello.world/foo) => "e.h.w/foo"

format-pstats clj/s

(format-pstats ps)

(format-pstats ps opts)

Formats given pstats to a string table. Accounted < Clock => Some work was done that wasn't tracked by any p forms. Accounted > Clock => Nested p forms, and/or parallel threads.

handlers_ clj/s

{<handler-id> <handler-fn>}

may-profile? clj/s

(may-profile? level)

(may-profile? level ns)

Implementation detail. Returns true iff level and ns are runtime unfiltered.

merge-pstats clj/s

(merge-pstats)

(merge-pstats ps0)

(merge-pstats ps0 ps1)

Statistics are lossless unless data to merge are very large.

new-pdata clj/s

(new-pdata)

(new-pdata {:keys [dynamic? nmax] :or {dynamic? true nmax default-nmax}})

Note: this is a low-level primitive for advanced users! Returns a new pdata object for use with with-profiling and/or capture-time!. Deref to get pstats:

(let [pd (new-pdata) t0 (System/nanoTime)] (with-profiling pd {} (p :foo (Thread/sleep 100)) (capture-time! pd :bar (- t0 (System/nanoTime)))) @pd)

Dynamic (thread-safe) by default. WARNING: don't change this default unless you're very sure the resulting pdata object will not be concurrently modified across threads. Concurrent modification will lead to bad data and/or exceptions!

p clj/s macro

(p id & body)

(p opts & body)

Profiling spy. Always executes body, and always returns <body-result>.

When [ns level] unelided and profiling is active, records execution time of body.

Compile-time opts: :id - Form id for this body in stats output (e.g. ::my-fn-call) :level - e/o #{0 1 2 3 4 5} ; Default is 5

profile clj/s macro

(profile opts & body)

Always executes body, and always returns <body-result>.

When [ns level] unelided and [ns level when] unfiltered, executes body with profiling active and dispatches stats to any registered handlers (see add-handler!).

Handy if you'd like to consume/aggregate stats output later/elsewhere. Otherwise see profiled.

Compile-time opts: :dynamic? - Use multi-threaded profiling? ; Default is false :nmax - ~Max captures per id before compaction ; Default is 8e5

Runtime opts: :level - e/o #{0 1 2 3 4 5} ; Default is 5 :when - Optional arbitrary conditional form (e.g. boolean expr) :id - Optional group id provided to handlers (e.g. ::my-stats-1) :data - Optional arbitrary data provided to handlers

Laziness in body: Lazy seqs and other forms of laziness (e.g. delays) in body will only contribute to profiling results if/when EVALUATION ACTUALLY OCCURS. This is intentional and a useful property. Compare:

(profile {} (delay (Thread/sleep 2000))) ; Doesn't count sleep (profile {} @(delay (Thread/sleep 2000))) ; Does count sleep

Async code in body: Execution time of any code in body that runs asynchronously on a different thread will generally NOT be automatically captured by default.

:dynamic? can be used to support capture in cases where Clojure's binding conveyance applies (e.g. futures, agents, pmap). Just make sure that all work you want to capture has COMPLETED before the profiled form ends- for example, by blocking on pending futures.

In other advanced cases (notably core.async go blocks), please see with-profiling and capture-time!.

core.async warning: core.async code can be difficult to profile correctly without a deep understanding of precisely what it's doing under-the-covers.

Some general recommendations that can help keep things simple:

 - Try minimize the amount of code + logic in `go` blocks. Use `go`
   blocks for un/parking to get the data you need, then pass the data
   to external fns. Profile these fns (or in these fns), not in your
   `go` blocks.

 - In particular: you MUST NEVER have parking calls inside
   `(profiled {:dynamic? false} ...)`.

   This can lead to concurrency exceptions.

   If you must profile code within a go block, and you really want to
   include un/parking times, use `(profiled {:dynamic? true} ...)`
   instead.

profiled clj/s macro

(profiled opts & body)

Always executes body, and always returns [<body-result> <?pstats>].

When [ns level] unelided and [ns level when] unfiltered, executes body with profiling active.

Handy if you'd like to consume stats output directly. Otherwise see profile.

pstats objects are derefable and mergeable:

• @pstats -> {:stats {:n _ :min _ ...} :clock {:t0 _ :t1 _ :total _}}
• @(merge-pstats ps1 ps2) -> {:stats {:n _ :min _ ...} :clock {:t0 _ :t1 _ :total _}}

Full set of :stats keys: :n :min :max :mean :mad :sum :p25 :p50 :p75 :p90 :p95 :p99

Compile-time opts: :dynamic? - Use multi-threaded profiling? ; Default is false :nmax - ~Max captures per id before compaction ; Default is 8e5

Runtime opts: :level - e/o #{0 1 2 3 4 5} ; Default is 5 :when - Optional arbitrary conditional form (e.g. boolean expr)

Laziness in body: Lazy seqs and other forms of laziness (e.g. delays) in body will only contribute to profiling results if/when EVALUATION ACTUALLY OCCURS. This is intentional and a useful property. Compare:

(profiled {} (delay (Thread/sleep 2000))) ; Doesn't count sleep (profiled {} @(delay (Thread/sleep 2000))) ; Does count sleep

Async code in body: Execution time of any code in body that runs asynchronously on a different thread will generally NOT be automatically captured by default.

:dynamic? can be used to support capture in cases where Clojure's binding conveyance applies (e.g. futures, agents, pmap). Just make sure that all work you want to capture has COMPLETED before the profiled form ends- for example, by blocking on pending futures.

In other advanced cases (notably core.async go blocks), please see with-profiling and capture-time!.

core.async warning: core.async code can be difficult to profile correctly without a deep understanding of precisely what it's doing under-the-covers.

Some general recommendations that can help keep things simple:

 - Try minimize the amount of code + logic in `go` blocks. Use `go`
   blocks for un/parking to get the data you need, then pass the data
   to external fns. Profile these fns (or in these fns), not in your
   `go` blocks.

 - In particular: you MUST NEVER have parking calls inside
   `(profiled {:dynamic? false} ...)`.

   This can lead to concurrency exceptions.

   If you must profile code within a go block, and you really want to
   include un/parking times, use `(profiled {:dynamic? true} ...)`
   instead.

profiling? clj/s

(profiling?)

Returns e/o #{nil :thread :dynamic}.

pspy clj/s macro

(pspy & args)

p alias

refer-tufte clj

(refer-tufte)

(require '[taoensso.tufte :as tufte :refer [defnp p profiled profile]])

remove-handler! clj/s

(remove-handler! handler-id)

set-min-level! clj/s

(set-min-level! level)

Deprecated, just use alter-var-root

set-ns-pattern! clj/s

(set-ns-pattern! ns-pattern)

Deprecated, just use alter-var-root

stats-accumulator clj/s

(stats-accumulator)

Alpha, subject to change. Small util to help merge pstats from multiple runs or threads.

Returns a stateful StatsAccumulator (sacc) with:

• (sacc <group-id> <pstats>) ; Merges given pstats under given group id
• @sacc ; Drains accumulator and returns {<group-id> <merged-pstats>}

Note that you may want some kind of async/buffer/serialization mechanism in front of merge calls for performance (e.g. by using an agent).

See also add-accumulating-handler!, example clj project.

with-min-level clj/s macro

(with-min-level level & body)

Deprecated, just use binding

with-ns-pattern clj/s macro

(with-ns-pattern ns-pattern & body)

Deprecated, just use binding

with-profiling clj/s macro

(with-profiling pdata {:keys [dynamic? nmax] :or {nmax default-nmax}} & body)

Note: this is a low-level primitive for advanced users! Enables p forms in body and returns body's result.

If :dynamic? is false (default), body's evaluation MUST begin and end without interruption on the same thread. In particular this means that body MUST NOT contain any parking core.async calls.

See new-pdata for more info on low-level primitives.