sleep.runtime
Class ScriptLoader

java.lang.Object
  sleep.runtime.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

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

ScriptLoader()
initializes the script loader

Method Summary

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, Block code, java.util.Hashtable env) creates a Sleep script instance using the precompiled code, name, and shared environment.
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, 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	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(ScriptInstance script) unload a script
void	unloadScript(java.lang.String filename) 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.

loadScript

public ScriptInstance loadScript(java.lang.String name,
                                 java.lang.String code,
                                 java.util.Hashtable env)
                          throws YourCodeSucksException

loads the specified script

Throws:

YourCodeSucksException

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

compileScript

public Block compileScript(java.io.File file)
                    throws java.io.IOException,
                           YourCodeSucksException

compiles the specified script file

Throws:

java.io.IOException

YourCodeSucksException

compileScript

public Block compileScript(java.lang.String fileName)
                    throws java.io.IOException,
                           YourCodeSucksException

compiles the specified script file

Throws:

java.io.IOException

YourCodeSucksException

compileScript

public Block compileScript(java.lang.String name,
                           java.lang.String code)
                    throws YourCodeSucksException

compiles the specified script into a runnable block

Throws:

YourCodeSucksException

loadScript

public ScriptInstance loadScript(java.lang.String name,
                                 java.io.InputStream stream)
                          throws YourCodeSucksException,
                                 java.io.IOException

loads a script from the specified inputstream

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

loadScript

public ScriptInstance loadScript(java.lang.String fileName)
                          throws java.io.IOException,
                                 YourCodeSucksException

Loads the specified script file

Throws:

java.io.IOException

YourCodeSucksException

loadScript

public ScriptInstance loadScript(java.lang.String fileName,
                                 java.util.Hashtable env)
                          throws java.io.IOException,
                                 YourCodeSucksException

Loads the specified script file, uses the specified hashtable for the environment

Throws:

java.io.IOException

YourCodeSucksException

loadScript

public ScriptInstance loadScript(java.io.File file,
                                 java.util.Hashtable env)
                          throws java.io.IOException,
                                 YourCodeSucksException

Loads the specified script file, uses the specified hashtable for the environment

Throws:

java.io.IOException

YourCodeSucksException

loadScript

public ScriptInstance loadScript(java.io.File file)
                          throws java.io.IOException,
                                 YourCodeSucksException

Loads the specified script file

Throws:

java.io.IOException

YourCodeSucksException

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