从 Clojure测量对象内存消耗_Clojure_代码_相关文件_下载

# clj-memory-meter This library is a thin wrapper around [Java Agent for Memory Measurements](https://github.com/jbellis/jamm). It allows to inspect at runtime how much memory an object occupies together with all its child fields. Extra features compared to **jamm**: 1. Easy runtime loading (you can start using it at any time at the REPL, providing additional startup parameters is not necessary). 2. Human-readable size output. **jamm** JAR file is shipped together with **clj-memory-meter** and unpacked at runtime. ## Usage **JDK9+:** you must start the JVM with option `-Djdk.attach.allowAttachSelf`, otherwise the agent will not be able to dynamically attach to the running process. For Leiningen, add `:jvm-opts ["-Djdk.attach.allowAttachSelf"]` to `project.clj`. For Boot, start the process with environment variable `BOOT_JVM_OPTIONS="-Djdk.attach.allowAttachSelf"`. Add `com.clojure-goes-fast/clj-memory-meter` to your dependencies: [](https://clojars.org/com.clojure-goes-fast/clj-memory-meter) Once loaded, you can measure objects like this: ```clojure (require '[clj-memory-meter.core :as mm]) ;; measure calculates total memory occupancy of the object (mm/measure "Hello, world!") ;=> "72 B" (mm/measure []) ;=> "240 B" (mm/measure (into {} (map #(vector % (str %)) (range 100)))) ;=> "9.6 KB" ;; :shallow true calculates only memory occupied by the object itself, ;; without children (mm/measure (object-array (repeatedly 100 #(String. "hello"))) :shallow true) ;=> "416 B" (mm/measure (object-array (repeatedly 100 #(String. "hello")))) ;=> "2.8 KB" ;; :bytes true can be passed to return the raw number of bytes (mm/measure (object-array (repeatedly 100 #(String. "hello"))) :bytes true) ;=> 2848 ;; :debug true can be passed to print the object hierarchy. You can also pass an ;; integer number to limit the number of nested levels printed. (mm/measure (apply list (range 4)) :debug true) ; root [clojure.lang.PersistentList] 256 bytes (40 bytes) ; | ; +--_first [java.lang.Long] 24 bytes (24 bytes) ; | ; +--_rest [clojure.lang.PersistentList] 192 bytes (40 bytes) ; | ; +--_first [java.lang.Long] 24 bytes (24 bytes) ; | ; +--_rest [clojure.lang.PersistentList] 128 bytes (40 bytes) ; | ; +--_first [java.lang.Long] 24 bytes (24 bytes) ; | ; +--_rest [clojure.lang.PersistentList] 64 bytes (40 bytes) ; | ; +--_first [java.lang.Long] 24 bytes (24 bytes) ;; Custom MemoryMeter object can be passed. See what you can configure here: ;; https://github.com/jbellis/jamm/blob/master/src/org/github/jamm/MemoryMeter.java ``` ## License jamm is distributed under Apache-2.0. See [APACHE_PUBLIC_LICENSE](license/APACHE_PUBLIC_LICENSE) file. The location of the original repository is [https://github.com/jbellis/jamm](https://github.com/jbellis/jamm). --- clj-memory-meter is distributed under the Eclipse Public License. See [ECLIPSE_PUBLIC_LICENSE](license/ECLIPSE_PUBLIC_LICENSE). Copyright 2018-2020 Alexander Yakushev