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# Class w3c.tools.store.SimpleResourceStore

    java.lang.Object
       |
       +----w3c.tools.store.SimpleResourceStore

public class SimpleResourceStore
extends Object
implements ResourceStore

A very naive resource store. This resource store keeps all the resources in a file. It loads all resources (on a per-demand basis), and never unloads them.

##

manager
  Our resource store manager.

##

SimpleResourceStore()

##

acceptUnload()
  Can the resource store manager unload that store from memory.
addHolder(ResourceStoreHolder)
  Add a holder to that store.
addResource(Resource)
  Add a new resource to the resource store.
enumerateResourceIdentifiers()
  Enumerate all the resources identifier in this repository.
getFileAt(int)
  Get our file, positionned at the given position.
getIdentifier()
  Get the identifier for that store.
getResourceBytes(ResourceIndex, byte[])
  Get the bytes that are the pickled version of the given resource.
getVersion()
  Get the store format version number.
hasResource(String)
  Does this store defines this resource.
initialize(ResourceStoreManager, Object, File)
  Initialize this simple store with the given file.
internalSave(boolean)
  Internal save: save the repository back to disk.
loadIndex(Hashtable)
  Restore our whole index from our repository.
loadResource(String, Hashtable)
  Load a resource, or get one from the cache.
lockResource(ResourceLocker, Resource)
  Lock this resource in memory.
lookupResource(String)
  Lookup this resource.
main(String[])
markModified(Resource)
  Mark the given resource as being modified.
markUsed()
  Mark the store as having been used recently.
pickleResource(Resource, DataOutputStream)
  Pickle the given resource into the given output stream.
printIndex()
  Debug - print this resource store index.
removeHolder(ResourceStoreHolder)
  Remove a store holder.
removeResource(String)
  Remove a resource from this resource store.
renameResource(String, String)
  Rename a resource in the store.
save()
  Save all our modified resources back to our file.
saveResource(Resource)
  Save a given resource.
shutdown()
  Shutdown this store.
toString()
  Print a simple resource store.
unlockResource(ResourceLocker, Resource)
  Unlock this resource from memory.
warning(String)
  Emit the given string as a warning, to whoever it is appropriate.

##

manager

     protected ResourceStoreManager manager

  Our resource store manager.

##

SimpleResourceStore

     public SimpleResourceStore()

##

markUsed

     protected final void markUsed()

  Mark the store as having been used recently.

addHolder

     public synchronized void addHolder(ResourceStoreHolder holder)

  Add a holder to that store.

  Parameters:
    holder - The holder to add.

removeHolder

     public synchronized void removeHolder(ResourceStoreHolder holder)

  Remove a store holder.

  Parameters:
    holder - The holder to remove.

getIdentifier

     public String getIdentifier()

  Get the identifier for that store. We use the repository as an identifier, which is safe here.

  Returns:
    The absolute path of the repository.

warning

     protected void warning(String msg)

  Emit the given string as a warning, to whoever it is appropriate.

  Parameters:
    msg - The warning message.

getFileAt

     protected RandomAccessFile getFileAt(int pos) throws IOException

  Get our file, positionned at the given position. We won't keep our repository file always open (too much of these resource stroe would burn our available file descriptors).

  Parameters:
    at - The position at wich you want the stream.

loadIndex

     protected synchronized void loadIndex(Hashtable target) throws IOException

  Restore our whole index from our repository.

printIndex

     protected void printIndex()

  Debug - print this resource store index.

getResourceBytes

     protected synchronized byte[] getResourceBytes(ResourceIndex index,
                                                    byte into[]) throws IOException

  Get the bytes that are the pickled version of the given resource. This opens the file for each resource, it could of course be optimized for the cases were all the resources are to be loaded at once.

  Parameters:
    identifier - The resource identifier.
  Returns:
    The length, in the instance buffer, of the bytes that makes this resource.

pickleResource

     protected int pickleResource(Resource resource,
                                  DataOutputStream out) throws IOException

  Pickle the given resource into the given output stream.

  Parameters:
    resource - The resource to pickle.
    out - The data output stream to pickle to.
  Returns:
    The size of the pickled version of the resource.

getVersion

     public int getVersion()

  Get the store format version number.

  Returns:
    An ineteger version number, guaranteed to change whenever the format used by the store changes.

loadResource

     public Resource loadResource(String identifier,
                                  Hashtable defs) throws InvalidResourceException

  Load a resource, or get one from the cache.

  Parameters:
    identifier - The resource identifier.
  Returns:
    A Resource instance, or null if the resource doesn't exist in that store.
  Throws: InvalidResourceException
    If the resource couldn't be restored from its pickled format.

internalSave

     protected synchronized void internalSave(boolean unload) throws IOException

  Internal save: save the repository back to disk.

  Parameters:
    unload - Should we unload any existing resources ?

lookupResource

     public Resource lookupResource(String identifier)

  Lookup this resource.

  Parameters:
    identifier - The resource identifier.
  Returns:
    A Resource instance, or null if either the resource doesn't exist, or it isn't loaded yet.

saveResource

     public void saveResource(Resource resource)

  Save a given resource. If the resource has been modified, we save all our resources.

  Parameters:
    resource - The resource to be save right now.

lockResource

     public synchronized boolean lockResource(ResourceLocker locker,
                                              Resource resource)

  Lock this resource in memory.

  Parameters:
    locker - The object willing to acuiqre the lock.
    identifier - The resource to lock.
  Returns:
    A boolean true if the locking succeeds.

unlockResource

     public synchronized void unlockResource(ResourceLocker locker,
                                             Resource resource)

  Unlock this resource from memory.

  Parameters:
    lcoker - The object willing to relinquish the lock.
    identifier - The resource to unlock.

addResource

     public synchronized void addResource(Resource resource)

  Add a new resource to the resource store.

  Parameters:
    resource - The resource to add.

removeResource

     public synchronized void removeResource(String identifier)

  Remove a resource from this resource store.

  Parameters:
    identifier - The identifier of the resource to be removed.

renameResource

     public synchronized void renameResource(String oldid,
                                             String newid)

  Rename a resource in the store.

  Parameters:
    oldid - The old resource identifier.
    newid - The new resource identifier.

markModified

     public synchronized void markModified(Resource resource)

  Mark the given resource as being modified.

  Parameters:
    identifier - The identifier of the modified resource.

acceptUnload

     public synchronized boolean acceptUnload()

  Can the resource store manager unload that store from memory. We check all the loaded resource, to see if they are willing to be unloaded; we do unload straight all the resources that accept (to reduce memory usage), and return false only if one of our resource refuse to be unloaded.

shutdown

     public synchronized void shutdown()

  Shutdown this store.

save

     public synchronized void save()

  Save all our modified resources back to our file.

enumerateResourceIdentifiers

     public Enumeration enumerateResourceIdentifiers()

  Enumerate all the resources identifier in this repository.

hasResource

     public boolean hasResource(String identifier)

  Does this store defines this resource.

  Parameters:
    identifier - The resource we are looking for.
  Returns:
    A boolean true if found.

toString

     public String toString()

  Print a simple resource store.

  Overrides:
    toString in class Object

initialize

     public void initialize(ResourceStoreManager manager,
                            Object token,
                            File repository)

  Initialize this simple store with the given file.

  Parameters:
    manager - The resource store manager that loaded use.
    token - Our identification token from the above resource store manager (this is an opaque object).
    file - The repository file.

main

     public static void main(String args[]) throws Exception

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