[rfc] [icedtea-web] make PAthsAndFilles to follow seted paths IV - bubble to CacheLruWrapper

[Jiri Vanek]

There are/were/reappeared two issues in LRUwrapper and CacheUtils

First the file - however crated was as value,not as pointer. So whatever happened to original, had not bubbled to lruwrapper/utils.
Second - the methods were using getters on field, whcch could change during the method invocation.

This pathc should fix both of them.

The main refactoring is
-    public CacheLRUWrapper(final File recentlyUsed, final File cacheDir) {
-        recentlyUsedPropertiesFile = new PropertiesFile(recentlyUsed);
+    public CacheLRUWrapper(final InfrastructureFileDescriptor recentlyUsed, final InfrastructureFileDescriptor cacheDir) {
+        recentlyUsedPropertiesFile = recentlyUsed;

Now the cache lru wrapper is handling the "pointers" to sources. So any call to its "getFiles" get real value fromm PathsAndFiles
When any method is using its getFile it alwasy save current copy, co during runtime, it will not be affected by possible change.

The exception is

-    public PropertiesFile getRecentlyUsedPropertiesFile() {
-        return recentlyUsedPropertiesFile;
+    PropertiesFile getRecentlyUsedPropertiesFile() {
+        if (cachedPropertiesFile == null) {
+            //no properties file yet, create it
+            cachedPropertiesFile = new PropertiesFile(recentlyUsedPropertiesFile.getFile());
+            return cachedPropertiesFile;
+        }
+        if (recentlyUsedPropertiesFile.getFile().equals(cachedPropertiesFile.getStoreFile())){
+            //he underlying InfrastructureFileDescriptor is still poinitng to the same file, use current proeprties file
+            return cachedPropertiesFile;
+        } else {
+            //the InfrastructureFileDescriptor was set to different location, move to it
+            //is there something needed to close previous instance?
+            cachedPropertiesFile.store();
+            cachedPropertiesFile.unlock();
+            //above were just shotted here
+            cachedPropertiesFile = new PropertiesFile(recentlyUsedPropertiesFile.getFile());
+            return cachedPropertiesFile;
+        }
+


When something change value path to properties file *and* call getRecentlyUsedPropertiesFile then the file will store and unlock. (note - I dont know for sure if those two are needed, but afaik yes). So actions upo  previous Prop.File  may misbehave.
However .. The setter to the RECENTLY_USED_FILE and KEY_USER_CACHE_DIR is used *only* in tests (and should never be used in ITW itself)
Afaik - whole those will work if you run javaws (keep running) change proeprties, run second javaws. I noticed no issues. Everything was correctly cached  twice


There is one aditional refactoring in this patch - sorry for that - InfrastructureFileDescriptor moved from inner class to outer class. With one change -
+    //simple constructor to allow testing instances base don overrides
+    protected InfrastructureFileDescriptor() {
+        this("nope", "nope", "nope", "nope");
+    }


At the end, I consider this 4 pathces + lrucaches singleton + PAthsAndFiles as reallly good thing which happend to itw.


Jie - Is this enough for your "[rfc][icedtea-web] Use temporary cache in *" or is there something more to be done?


J.