[OFBiz] Dev - caching questions

[Si Chen]

Hi David,

Thanks.  I am creating here a HashMap of contentTypeId -> contentCaches, 
each of which is a UtilCache object.  Then when the contentTypeId is 
requested, I am going into the HashMap to get the UtilCache for that 
contentTypeId and using the get, put methods on the UtilCache.  Do you 
think there is another way to make many caches available for all the 
possible content types?

Si


David E. Jones wrote:

>
> Si,
>
> Use UtilCache for caches like this. It is there so we can have much  
> more control over cache management and such.
>
> As for size, we added some stuff for this recently to UtilCache, 
> though  it isn't 100% reliable (and we don't know of anything that is 
> for Java  at this point...).
>
> -David
>
>
> On Sep 22, 2004, at 11:56 AM, Si Chen wrote:
>
>> Hi David,
>>
>> Thanks for your tips on caching.  What do you (and Al) think of this  
>> code for the product content wrapper?  I set up a Map of caches, one  
>> for each product content type, and am using it to cache the results 
>> of  the ProductContentWrapper, so that product content such as 
>> names,  descriptions, can be available faster (especially if the 
>> content were  complicated and had freemarker rendering.)  The caches 
>> use soft  refrence.  I did not do the synchronized checking--do you 
>> think that  would be necessary?  One potential problem is if the 
>> content were  really big, such as a big image.  When I looked through 
>> the content  types, and the only one which might be a problem is the 
>> digital  download.  Do you think the content wrapper would/should be 
>> used to  return large content back?
>>
>> Also, as for monitoring the sizes of the cache, I noticed that there  
>> is the size() method for finding out how many entries there are in 
>> the  cache.  But is there anything to find out the amount of memory 
>> the  cache has actually taken up, or should I just do that through 
>> my  operating system?
>>
>> Thanks,
>>
>> Si
>> Index: ProductContentWrapper.java
>> ===================================================================
>> RCS file:  
>> /usr/local/cvs/ofbiz/components/product/src/org/ofbiz/product/product/ 
>> ProductContentWrapper.java,v
>> retrieving revision 1.1.1.1
>> diff -u -w -r1.1.1.1 ProductContentWrapper.java
>> --- ProductContentWrapper.java    6 Apr 2004 07:00:02 -0000    1.1.1.1
>> +++ ProductContentWrapper.java    22 Sep 2004 17:48:18 -0000
>> @@ -30,11 +30,14 @@
>>  import java.util.List;
>>  import java.util.Locale;
>>  import java.util.Map;
>> +import java.util.ArrayList;
>> +import java.util.Iterator;
>>
>>  import javax.servlet.http.HttpServletRequest;
>>
>>  import org.ofbiz.base.util.Debug;
>>  import org.ofbiz.base.util.GeneralException;
>> +import org.ofbiz.base.util.UtilCache;
>>  import org.ofbiz.base.util.UtilHttp;
>>  import org.ofbiz.base.util.UtilMisc;
>>  import org.ofbiz.base.util.UtilValidate;
>> @@ -60,20 +63,47 @@
>>      protected Locale locale;
>>      protected String mimeTypeId;
>>
>> +    protected static Map caches;
>> +
>>      public static ProductContentWrapper  
>> makeProductContentWrapper(GenericValue product, HttpServletRequest  
>> request) {
>>          return new ProductContentWrapper(product, request);
>>      }
>>
>> +    private Map makeProductContentCaches(GenericDelegator delegator) {
>> +        Map contentCaches = new HashMap();
>> +        List contentTypes = new ArrayList();
>> +       
>> +        try {
>> +            contentTypes = delegator.findAll("ProductContentType");
>> +           
>> +            for (Iterator cTi = contentTypes.iterator(); 
>> cTi.hasNext(); ) {
>> +                String nextContentType = ((GenericValue)  
>> cTi.next()).getString("productContentTypeId");
>> +                contentCaches.put(nextContentType, new  
>> UtilCache("product.content." + nextContentType, true));
>> +                Debug.logInfo("Creating product content cache for " 
>> +  nextContentType, module);
>> +            }
>> +        } catch (GeneralException ex) {
>> +            Debug.logError(ex, "Cannot build product content cache 
>> table",  module);
>> +        }
>> +       
>> +        return contentCaches;
>> +    }
>> +
>>      public ProductContentWrapper(GenericValue product, Locale 
>> locale,  String mimeTypeId) {
>>          this.product = product;
>>          this.locale = locale;
>>          this.mimeTypeId = mimeTypeId;
>> +        if (caches == null) {       
>> +            caches = makeProductContentCaches(product.getDelegator());
>> +        }
>>      }
>>
>>      public ProductContentWrapper(GenericValue product,  
>> HttpServletRequest request) {
>>          this.product = product;
>>          this.locale = UtilHttp.getLocale(request);
>>          this.mimeTypeId = "text/html";
>> +        if (caches == null) {
>> +            caches = makeProductContentCaches(product.getDelegator());
>> +        }
>>      }
>>
>>      public String get(String productContentTypeId) {
>> @@ -91,10 +121,24 @@
>>      public static String getProductContentAsText(GenericValue  
>> product, String productContentTypeId, Locale locale, String  
>> mimeTypeId, GenericDelegator delegator) {
>>          String candidateFieldName =  
>> ModelUtil.dbNameToVarName(productContentTypeId);
>>          try {
>> +            UtilCache contentCache = null;
>> +            if (caches.get(productContentTypeId) != null) {
>> +                contentCache = (UtilCache)  
>> caches.get(productContentTypeId);
>> +            }
>> +
>> +            if (contentCache != null &&  
>> contentCache.get(product.get("productId")) != null) {
>> +                Debug.logInfo("found content cache for " +  
>> product.get("productId") + "; will be returning " +  
>> contentCache.get(product.get("productId")), module);
>> +                return (String)  
>> contentCache.get(product.get("productId"));
>> +            }
>> +           
>>              Writer outWriter = new StringWriter();
>>              getProductContentAsText(null, product,  
>> productContentTypeId, locale, mimeTypeId, delegator, outWriter);
>>              String outString = outWriter.toString();
>>              if (outString.length() > 0) {
>> +                if (contentCache != null) {
>> +                    Debug.logInfo("putting " + outString + " into 
>> content  cache under " + product.get("productId"), module);
>> +                    contentCache.put(product.get("productId"), 
>> outString);
>> +                }
>>                  return outString;
>>              } else {
>>                  return null;
>>
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>> http://lists.ofbiz.org/mailman/listinfo/dev
>
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