Class HeapProfiler

  • public class HeapProfiler
extends java.lang.Object

    This class was built using the Chrome Remote Dev-Tools A.P.I., which is specified by two JSON-RPC Files. These files were obtained from the Chrome Dev Tools Protocol Git Hub Page, which has a "Tip of Tree" (the latest) API-Specification Page Here: JSON-RPC Protocol Specification.

    These files were converted into this Java-Browser (CDP) Library. The intention is to have them function in a similar fasion to the Node.js Tool known as 'Puppeteer', Microsoft's 'Playwright' and of course the Main-Stay 'Selenium.' The Java-HTML JAR Library merely implements the Java Types & Commands defined by Google's DevTools Protocol.

    🧠 View the Google CDP API:

    [No Description Provided by Google]

    The top-level description and explanation for this class (this comment, at the top this Java-Doc Page) is repeated, verbatim, across all of the domain classes which comprise Google's CDP API.

    This class is intended to be used with a Browser Instance

    These methods have been tested, to some degree, using Google Chrome. In order to use this class you must start a web-browser instance and make a connection to the browser using a Remote Debugging Port. Google-Corporation is the developer of this API, but any browser which accepts a Remote Debug Port Connection over Web-Sockets.

    Google-Chrome was used during the development process of the classes in this particular package. Lately, it has been asserted Microsoft has switched to using the Chrome Browser-Engine for its Microsoft Edge Internal Code-Base. Therefore, there may some functionality available when running the methods in this class with Microsoft-Edge.

    Check whether the your Web-Browser will allow itself to be driven by the Web-Socket RDP-Port 9223. See the examples available in package Torello.Browser to undertand how to build a PageConn and BrowserConn Web-Socket Connection, and how to build a WebSocketSender instance in order to execute the methods in this class.

    Web-Socket & JSON API:   
    Every one of the methods that reside in this class are designed to do nothing more than:

    1. Accept Parameters from the User, and "Marshall Them" into a Valid JSON-Request
    2. Transmit the Marshalled Request-JSON to a Headless Web-Browser over a Web-Socket Connection
    3. Receive BOTH that Command-Results AND any Browser Event-Firings from the Web-Socket
    4. Parse JSON Method-Results and Browser-Event Firings, and Subsequently Convert them to Standard Java-Types
    5. Report these Method-Results and Browser-Events to the User via a User-Registered, Event-Listener (Events) or a Promise Object (Command Responses / Results)

    Unlike the bulk of the Java HTML JAR Library, there is very little native Java-Code, and very little testing that may be done on any of the classes & methods in this package. The code inside these classes does nothing more than marshall-and-unmarshall Java-Types into Json-Requests (and vice-versa). The Java-Script & Browser modules inside of a Google-Chrome instance are, theoretically, handling these requests, and returning their results (or events) over the Web-Socket Connection.

    It has been asserted (by Google Chrome Developers) that some of these methods are only "partially working" or "experimental".


    Asking Chat-GPT for Help:   
    The LLM otherwise known as "Chat-GPT" does, indeed, have an expert level of knowledge about the "Remote DevTools Protocol". The API that the Chrome DevTools Protocl (CDP) exports is extremely well understood by the LLM, and generally I have found that Chat-GPT understands (by 2 or 3 orders of magnitude) better what my Auto-Generated JSON-Wrappers can do in controlling a Web-Browser than I could ever possibly hope to understand.

    Though not available today, there will soon be an automatically downloadable Token-Stream (AI Embeddings) BUTTON available on my Java-Doc Pages that should hopefully make it extremely easy to post my code-base, RAG Style, to Chat-GPT and other LLM's when 'interogating' them. Presently, because my "Get Token Stream Button" does not exist yet on any of my pages, what you can do is copy-and-paste any Method-Signature from any one of these pages and then ask Chat-GPT to explain what that Browser or Java-Script Function is actually doing. It is very likely to give you some pretty neat answers.

    I have found that every single one of the Domains, Types & Events which are offered by the CDP Protocol (though not documented very well by Google), are perfectly understood by the A.I. LLM - literally to the point where it does know (much better than I ever could) what my own code base actually does!

    Try it out, it's a lot of fun. Note that this package and these classes were originally developed solely to be able to execute the Java-Script that a browser executes when visiting a Web-Site. Complete HTML-Page Content can be scraped (using the HTML Data-Scraping Tools in Java-HTML) off of Web-Sites that have dynamic / Java-Script Generated Content.


    Conspicuous Boxed-Types Usage:
    You may notice that there are many methods that have parameters which accept, for instance, an Integer, instead of a primitive int. Just to remind the readiner, in Java Programs a Boxed Type is a standard Java-Primitive which has been converted into an Object-Reference. The use of Boxed-Types in this code base is an easy-and-fast-way to allow for the concept of "Optional Parameters" or "Optional Field Value."

    Whenever you see a method that accepts an Integer, the reason for this Parameter-Type choice is actually to allow a user to pass 'null' to it. This is a simple way to ELIDE passing any value at all to parameters which Google-Chrome would otherwise assert are "Optional." Whenever you pass 'null' to a Boxed-Types in this class, the Json-Processor will simply eliminate that Object-Property from the command altogether; and the browser will simply not receive any value for that parameter when that command is invoked.

    The Java Language Specification does not have an easy or well defined means of accepting optional method parameters; so Boxed-Types and 'null' are utilized here. Note that 'null' may be passed to any Command Method-Parameter that is listed as Optional on the Java-Doc Page description for that parameter.



    Stateless Class:
    This class neither contains any program-state, nor can it be instantiated. The @StaticFunctional Annotation may also be called 'The Spaghetti Report'. Static-Functional classes are, essentially, C-Styled Files, without any constructors or non-static member fields. It is a concept very similar to the Java-Bean's @Stateless Annotation.

    • 1 Constructor(s), 1 declared private, zero-argument constructor
    • 12 Method(s), 12 declared static
    • 2 Field(s), 2 declared static, 2 declared final


    • Field Detail

      • HeapSnapshotObjectId

        🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static final java.lang.String HeapSnapshotObjectId
        Heap snapshot object id.

        The Type HeapSnapshotObjectId has been eliminated, because it is a direct mapping to a basic Java-Type; it has no additional fields, or other distinguishing properties. Instead, this CDP defined type has been relegated to a simple String Constant, for documentation & reference purposes only.

        The code which is generated which employs this type replaces its use with the Standard Java-Type: String

        Eliminated Type
        See Also:
        Constant Field Values

      • resetProfiles

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static final java.lang.String resetProfiles
        [No Description Provided by Google]

        This is Marker-Event. Marker-Event's are events that do not possess any data or fields at all. When such events are fired by the browser, the Web-Socket sends nothing more than the name of the event in the packet. The Java-HTML CDP Implementation (this library) has not actually created a dedicated Java Event-Type for this Browser Event.

        This specific static field is actually just declared a String.
        resetProfiles has not been 'reified' into an actual nested / inner class of its own, at all.

        Eliminated Event Type
        See Also:
        Constant Field Values

    • Method Detail

      • addInspectedHeapObject

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static Script<java.lang.Void> addInspectedHeapObject​
            (java.lang.String heapObjectId)
        Enables console to refer to the node with given id via $x (see Command Line API for more details $x functions).
        Parameters:
        heapObjectId - Heap snapshot object id to be accessible by means of $x command line API.
        Returns:
        An instance of Script<Void>

        This Script instance must be executed before the browser receives the invocation-request.

        This Browser-Function does not have a return-value. You may choose to await the Promise<Void> to ensure that the Browser Function has run to completion.

      • collectGarbage

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static Script<java.lang.Void> collectGarbage()
        [No Description Provided by Google]
        Returns:
        An instance of Script<Void>

        This Script instance must be executed before the browser receives the invocation-request.

        This Browser-Function does not have a return-value. You may choose to await the Promise<Void> to ensure that the Browser Function has run to completion.

      • disable

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static Script<java.lang.Void> disable()
        [No Description Provided by Google]
        Returns:
        An instance of Script<Void>

        This Script instance must be executed before the browser receives the invocation-request.

        This Browser-Function does not have a return-value. You may choose to await the Promise<Void> to ensure that the Browser Function has run to completion.

      • enable

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static Script<java.lang.Void> enable()
        [No Description Provided by Google]
        Returns:
        An instance of Script<Void>

        This Script instance must be executed before the browser receives the invocation-request.

        This Browser-Function does not have a return-value. You may choose to await the Promise<Void> to ensure that the Browser Function has run to completion.

      • getHeapObjectId

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static Script<java.lang.String> getHeapObjectId​
            (java.lang.String objectId)
        [No Description Provided by Google]
        Parameters:
        objectId - Identifier of the object to get heap object id for.
        Returns:
        An instance of Script<String>

        This script may be executed, using Script.exec, and afterwards, a Promise <String> will be returned

        Finally, the Promise may be awaited, using Promise.await(), and the returned result of this Browser Function may be retrieved.

        This Browser Function's Promise returns: String (heapSnapshotObjectId)
        Id of the heap snapshot object corresponding to the passed remote object id.

      • startSampling

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static Script<java.lang.Void> startSampling​
            (java.lang.Number samplingInterval,
             java.lang.Boolean includeObjectsCollectedByMajorGC,
             java.lang.Boolean includeObjectsCollectedByMinorGC)
        [No Description Provided by Google]
        Parameters:
        samplingInterval - Average sample interval in bytes. Poisson distribution is used for the intervals. The default value is 32768 bytes.
        OPTIONAL
        includeObjectsCollectedByMajorGC - By default, the sampling heap profiler reports only objects which are still alive when the profile is returned via getSamplingProfile or stopSampling, which is useful for determining what functions contribute the most to steady-state memory usage. This flag instructs the sampling heap profiler to also include information about objects discarded by major GC, which will show which functions cause large temporary memory usage or long GC pauses.
        OPTIONAL
        includeObjectsCollectedByMinorGC - By default, the sampling heap profiler reports only objects which are still alive when the profile is returned via getSamplingProfile or stopSampling, which is useful for determining what functions contribute the most to steady-state memory usage. This flag instructs the sampling heap profiler to also include information about objects discarded by minor GC, which is useful when tuning a latency-sensitive application for minimal GC activity.
        OPTIONAL
        Returns:
        An instance of Script<Void>

        This Script instance must be executed before the browser receives the invocation-request.

        This Browser-Function does not have a return-value. You may choose to await the Promise<Void> to ensure that the Browser Function has run to completion.

      • startTrackingHeapObjects

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static Script<java.lang.Void> startTrackingHeapObjects​
            (java.lang.Boolean trackAllocations)
        [No Description Provided by Google]
        Parameters:
        trackAllocations - -
        OPTIONAL
        Returns:
        An instance of Script<Void>

        This Script instance must be executed before the browser receives the invocation-request.

        This Browser-Function does not have a return-value. You may choose to await the Promise<Void> to ensure that the Browser Function has run to completion.

      • stopTrackingHeapObjects

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static Script<java.lang.Void> stopTrackingHeapObjects​
            (java.lang.Boolean reportProgress,
             java.lang.Boolean treatGlobalObjectsAsRoots,
             java.lang.Boolean captureNumericValue,
             java.lang.Boolean exposeInternals)
        [No Description Provided by Google]
        Parameters:
        reportProgress - If true 'reportHeapSnapshotProgress' events will be generated while snapshot is being taken when the tracking is stopped.
        OPTIONAL
        treatGlobalObjectsAsRoots - Deprecated in favor of exposeInternals.
        OPTIONALDEPRECATED
        captureNumericValue - If true, numerical values are included in the snapshot
        OPTIONAL
        exposeInternals - If true, exposes internals of the snapshot.
        OPTIONALEXPERIMENTAL
        Returns:
        An instance of Script<Void>

        This Script instance must be executed before the browser receives the invocation-request.

        This Browser-Function does not have a return-value. You may choose to await the Promise<Void> to ensure that the Browser Function has run to completion.

      • takeHeapSnapshot

        🡅  ⇈  ⮫ 🗕  🗗  🗖 
        public static Script<java.lang.Void> takeHeapSnapshot​
            (java.lang.Boolean reportProgress,
             java.lang.Boolean treatGlobalObjectsAsRoots,
             java.lang.Boolean captureNumericValue,
             java.lang.Boolean exposeInternals)
        [No Description Provided by Google]
        Parameters:
        reportProgress - If true 'reportHeapSnapshotProgress' events will be generated while snapshot is being taken.
        OPTIONAL
        treatGlobalObjectsAsRoots - If true, a raw snapshot without artificial roots will be generated. Deprecated in favor of exposeInternals.
        OPTIONALDEPRECATED
        captureNumericValue - If true, numerical values are included in the snapshot
        OPTIONAL
        exposeInternals - If true, exposes internals of the snapshot.
        OPTIONALEXPERIMENTAL
        Returns:
        An instance of Script<Void>

        This Script instance must be executed before the browser receives the invocation-request.

        This Browser-Function does not have a return-value. You may choose to await the Promise<Void> to ensure that the Browser Function has run to completion.