Package sleep.runtime

Class ScriptLoader


  • public class ScriptLoader
    extends java.lang.Object

    The ScriptLoader is a convienence container for instantiating and managing ScriptInstances.

    To load a script from a file and run it:

     ScriptLoader   loader = new ScriptLoader();
     ScriptInstance script = loader.loadScript("script.sl");
    
     script.runScript();
     

    The above will load the file script.sl and then execute it immediately.

    Installation of loadable bridges you create can also be managed by the ScriptLoader.

    A loadable bridge is installed into the language by adding it to a script loader class. There are two types of bridges. The two types are specific and global bridges.

    The load and unload methods for a specific bridge are executed for every script load and unload, no matter what.

    A global bridge is installed once for each script environment. If scripts are sharing an environment there is no sense in loading stuff into the environment more than once. This is why global bridges exist.

    An example of adding a loadable bridge to a script loader:

     ScriptLoader loader = new ScriptLoader()
     loader.addSpecificBridge(new MyLoadableBridge());
     

    There is a difference between "loading" and "compiling" a script:

    This class contains several methods to either load or compile a script. Loading a script instantiates a script environment, registers the script with the script loader, and registers all of the appropriate bridges with the script on top of compiling the script.

    To compile a script means to produce a runnable Block of code. On its own a Block is not really runnable as a script environment is needed. For functions eval(), include(), etc.. it makes sense to compile a script as you may want to run the block of code within the environment of the calling script. Using the compile method saves on the overhead of unnecessary script environment creation and bridge registration.

    Management of Script Reloading

    The ScriptInstance class has a an associateFile method to associate a source File object with a script. The &include function calls this method when a file is included into the current script context. To check if any of the associated files has changed call hasChanged on the appropriate ScriptInstance.

    The ScriptLoader will automatically associate a source file with a ScriptInstance when a File object is passed to loadScript. If you choose to do some voodoo compiling scripts and managing your own cache (not necessary btw) then you will have to call associateFile against any ScriptInstance you construct

    Script Cache

    The ScriptLoader mantains a cache of Blocks. These are indexed by name and a timestamp of when they were created. You may call the touch method with the name and a timestamp to allow the ScriptLoader to invalidate the cache entry. If you just load scripts from files then the script cache will just work. To disable the cache use loader.setGlobalCache(false).

    Hopefully this helped to clarify things. :)

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected static java.util.Map BLOCK_CACHE
      cache for parsed scripts mantained (optionally) by the script loader.
      protected java.util.LinkedList bridgesg
      global bridges
      protected java.util.LinkedList bridgess
      specific bridges
      protected boolean disableConversions  
      protected java.util.LinkedList loadedScripts
      loaded scripts
      protected java.util.LinkedList paths
      path to search for jar files imported using [import * from: *] syntax
      protected java.util.Map scripts
      loaded scripts except referable by key
    • Constructor Summary

      Constructors 
      Constructor Description
      ScriptLoader()
      initializes the script loader
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void addGlobalBridge​(Loadable l)
      A global bridge is loaded into an environment once and only once.
      void addSpecificBridge​(Loadable l)
      A specific bridge is loaded into *every* script regardless of wether or not the environment is shared.
      Block compileScript​(java.io.File file)
      compiles the specified script file
      Block compileScript​(java.lang.String fileName)
      compiles the specified script file
      Block compileScript​(java.lang.String name, java.io.InputStream stream)
      compiles a script using the specified stream as a source
      Block compileScript​(java.lang.String name, java.lang.String code)
      compiles the specified script into a runnable block
      java.lang.String getCharset()  
      ScriptEnvironment getFirstScriptEnvironment()
      Convienence method to return the script environment of the first script tht was loaded, returns null if no scripts are loaded
      java.util.LinkedList getScripts()
      Returns a linked list of all loaded ScriptInstance objects
      java.util.Map getScriptsByKey()
      Returns a HashMap with all loaded scripts, the key is a string which is just the filename, the value is a ScriptInstance object
      java.util.Set getScriptsToLoad​(java.util.Set configured)
      A convienence method to determine the set of scripts to "load" based on a passed in set of scripts that are currently configured.
      java.util.Set getScriptsToUnload​(java.util.Set configured)
      A convienence method to determine the set of scripts to "unload" based on a passed in set of scripts that are currently configured.
      protected void initDefaultBridges()
      method call to initialize the default bridges, if you want to change the default bridges subclass this class and override this method
      protected void inProcessScript​(java.lang.String name, ScriptInstance si)
      Process the newly loaded script.
      boolean isCharsetConversions()  
      boolean isLoaded​(java.lang.String name)
      Determines wether or not the script is loaded by checking if the specified key exists in the script db.
      ScriptInstance loadScript​(java.io.File file)
      Loads the specified script file
      ScriptInstance loadScript​(java.io.File file, java.util.Hashtable env)
      Loads the specified script file, uses the specified hashtable for the environment
      ScriptInstance loadScript​(java.lang.String fileName)
      Loads the specified script file
      ScriptInstance loadScript​(java.lang.String name, java.io.InputStream stream)
      loads a script from the specified inputstream
      ScriptInstance loadScript​(java.lang.String name, java.io.InputStream stream, java.util.Hashtable env)
      loads a script from the specified input stream using the specified hashtable as a shared environment
      ScriptInstance loadScript​(java.lang.String name, java.lang.String code, java.util.Hashtable env)
      loads the specified script
      ScriptInstance loadScript​(java.lang.String fileName, java.util.Hashtable env)
      Loads the specified script file, uses the specified hashtable for the environment
      ScriptInstance loadScript​(java.lang.String name, Block code, java.util.Hashtable env)
      creates a Sleep script instance using the precompiled code, name, and shared environment.
      ScriptInstance loadScriptNoReference​(java.lang.String name, Block code, java.util.Hashtable env)
      creates a Sleep script instance using the precompiled code, name, and shared environment.
      ScriptInstance loadSerialized​(java.io.File script, java.util.Hashtable env)
      Load a serialized version of the script iff a serialized version exists, and its modification time is greater than the modification time of the script.
      ScriptInstance loadSerialized​(java.lang.String name, java.io.InputStream stream, java.util.Hashtable env)
      Loads a serialized script from the specified input stream with the specified name
      static void saveSerialized​(ScriptInstance si)
      Saves a serialized version of the compiled script to scriptname.bin.
      static void saveSerialized​(ScriptInstance si, java.io.OutputStream stream)
      Saves a serialized version of the ScriptInstance si to the specified output stream
      void setCharset​(java.lang.String charset)
      If charset conversion is enabled and charset is set, then the stream will be read using specified charset.
      void setCharsetConversion​(boolean b)
      Java by default maps characters from an 8bit ascii file to an internal 32bit unicode representation.
      java.util.Map setGlobalCache​(boolean setting)
      The Sleep script loader can optionally cache parsed script files once they are loaded.
      void touch​(java.lang.String name, long lastModifiedTime)
      nudge the cache with the last modified time of the specified script.
      void unloadScript​(java.lang.String filename)
      unload a script
      void unloadScript​(ScriptInstance script)
      unload a script
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • BLOCK_CACHE

        protected static java.util.Map BLOCK_CACHE
        cache for parsed scripts mantained (optionally) by the script loader.
      • loadedScripts

        protected java.util.LinkedList loadedScripts
        loaded scripts
      • scripts

        protected java.util.Map scripts
        loaded scripts except referable by key
      • bridgesg

        protected java.util.LinkedList bridgesg
        global bridges
      • bridgess

        protected java.util.LinkedList bridgess
        specific bridges
      • paths

        protected java.util.LinkedList paths
        path to search for jar files imported using [import * from: *] syntax
      • disableConversions

        protected boolean disableConversions
    • Constructor Detail

      • ScriptLoader

        public ScriptLoader()
        initializes the script loader
    • Method Detail

      • touch

        public void touch​(java.lang.String name,
                          long lastModifiedTime)
        nudge the cache with the last modified time of the specified script. this call will delete the script from the cache if the lastModifiedTime > lastLoadTime
      • setGlobalCache

        public java.util.Map setGlobalCache​(boolean setting)
        The Sleep script loader can optionally cache parsed script files once they are loaded. This is useful if you will have several script loader instances loading the same script files in isolated objects.
      • initDefaultBridges

        protected void initDefaultBridges()
        method call to initialize the default bridges, if you want to change the default bridges subclass this class and override this method
      • addGlobalBridge

        public void addGlobalBridge​(Loadable l)
        A global bridge is loaded into an environment once and only once. This way if the environment is shared among multiple script instances this will save on both memory and script load time
      • addSpecificBridge

        public void addSpecificBridge​(Loadable l)
        A specific bridge is loaded into *every* script regardless of wether or not the environment is shared. Useful for modifying the script instance while it is being in processed. Specific bridges are the first thing that happens after the script code is parsed
      • getScriptsByKey

        public java.util.Map getScriptsByKey()
        Returns a HashMap with all loaded scripts, the key is a string which is just the filename, the value is a ScriptInstance object
      • isLoaded

        public boolean isLoaded​(java.lang.String name)
        Determines wether or not the script is loaded by checking if the specified key exists in the script db.
      • getFirstScriptEnvironment

        public ScriptEnvironment getFirstScriptEnvironment()
        Convienence method to return the script environment of the first script tht was loaded, returns null if no scripts are loaded
      • getScripts

        public java.util.LinkedList getScripts()
        Returns a linked list of all loaded ScriptInstance objects
      • inProcessScript

        protected void inProcessScript​(java.lang.String name,
                                       ScriptInstance si)
        Process the newly loaded script. Setup its name and load the bridges into the environment assuming this hasn't been done before.
      • loadSerialized

        public ScriptInstance loadSerialized​(java.io.File script,
                                             java.util.Hashtable env)
                                      throws java.io.IOException,
                                             java.lang.ClassNotFoundException
        Load a serialized version of the script iff a serialized version exists, and its modification time is greater than the modification time of the script. Also handles the muss and fuss of reserializing the script if it has to reload the script. Personally I didn't find much of a startup time decrease when loading the scripts serialized versus parsing them each time. Theres a command 'bload' in the console to benchmark loading a script normally versus serialized. Try it.
        Parameters:
        script - a file object pointing to the script file...
        Throws:
        java.io.IOException
        java.lang.ClassNotFoundException
      • loadSerialized

        public ScriptInstance loadSerialized​(java.lang.String name,
                                             java.io.InputStream stream,
                                             java.util.Hashtable env)
                                      throws java.io.IOException,
                                             java.lang.ClassNotFoundException
        Loads a serialized script from the specified input stream with the specified name
        Throws:
        java.io.IOException
        java.lang.ClassNotFoundException
      • saveSerialized

        public static void saveSerialized​(ScriptInstance si)
                                   throws java.io.IOException
        Saves a serialized version of the compiled script to scriptname.bin.
        Throws:
        java.io.IOException
      • saveSerialized

        public static void saveSerialized​(ScriptInstance si,
                                          java.io.OutputStream stream)
                                   throws java.io.IOException
        Saves a serialized version of the ScriptInstance si to the specified output stream
        Throws:
        java.io.IOException
      • loadScriptNoReference

        public ScriptInstance loadScriptNoReference​(java.lang.String name,
                                                    Block code,
                                                    java.util.Hashtable env)
        creates a Sleep script instance using the precompiled code, name, and shared environment. This function also processes the script using the global and specific bridges registered with this script loader. No reference to the newly created script is kept by the script loader
      • loadScript

        public ScriptInstance loadScript​(java.lang.String name,
                                         Block code,
                                         java.util.Hashtable env)
        creates a Sleep script instance using the precompiled code, name, and shared environment. This function also processes the script using the global and specific bridges registered with this script loader. The script is also referened by this loader so it can be processed again (during the unload phase) when unloadScript is called.
      • compileScript

        public Block compileScript​(java.lang.String name,
                                   java.io.InputStream stream)
                            throws YourCodeSucksException,
                                   java.io.IOException
        compiles a script using the specified stream as a source
        Throws:
        YourCodeSucksException
        java.io.IOException
      • loadScript

        public ScriptInstance loadScript​(java.lang.String name,
                                         java.io.InputStream stream,
                                         java.util.Hashtable env)
                                  throws YourCodeSucksException,
                                         java.io.IOException
        loads a script from the specified input stream using the specified hashtable as a shared environment
        Throws:
        YourCodeSucksException
        java.io.IOException
      • unloadScript

        public void unloadScript​(java.lang.String filename)
        unload a script
      • unloadScript

        public void unloadScript​(ScriptInstance script)
        unload a script
      • getScriptsToUnload

        public java.util.Set getScriptsToUnload​(java.util.Set configured)
        A convienence method to determine the set of scripts to "unload" based on a passed in set of scripts that are currently configured. The configured scripts are compared to the loaded scripts. Scripts that are loaded but not configured are determined to be in need of unloading. The return Set contains String objects of the script names. The passed in Set is expected to be the same thing (a bunch of Strings).
      • getScriptsToLoad

        public java.util.Set getScriptsToLoad​(java.util.Set configured)
        A convienence method to determine the set of scripts to "load" based on a passed in set of scripts that are currently configured. The configured scripts are compared to the loaded scripts. Scripts that are configured but not loaded are determined to be in need of loading. The return Set contains String objects of the script names. The passed in Set is expected to be the same thing (a bunch of Strings).
      • setCharsetConversion

        public void setCharsetConversion​(boolean b)
        Java by default maps characters from an 8bit ascii file to an internal 32bit unicode representation. How this mapping is done is called a character set encoding. Sometimes this conversion can frustrate scripters making them say "hey, I didn't put that character in my script". You can use this option to ensure sleep disables charset conversions for scripts loaded with this script loader
      • isCharsetConversions

        public boolean isCharsetConversions()
      • getCharset

        public java.lang.String getCharset()
      • setCharset

        public void setCharset​(java.lang.String charset)
        If charset conversion is enabled and charset is set, then the stream will be read using specified charset.
        Parameters:
        charset - The name of a supported charset