Transforming XML to DOM can incur considerable overhead. The ATG platform includes a separate document cache for XML documents, located at /atg/dynamo/service/xml/DocumentCache. This component can be used to cache the results of an XML to DOM parser. The servlet bean XMLTransform uses a document cache for XML input documents, and another for XSL stylesheet templates.
The XML document cache is similar to ATG’s file cache. It uses an LRU (least-recently-used) policy to maintain the cache, determining which entries to flush based upon expiration times and timestamps.
The XML document cache has the following configurable properties. A value of -1 indicates that the value is unlimited.
Property | Default | Type | Description |
|---|---|---|---|
| -1 |
| Maximum number of cache entries. |
| 2000000 |
| Maximum size of the cache, in bytes |
| -1 |
| Time in milliseconds before a cache entry expires. |
| -1 |
| Maximum size for any single entry in the cache, in bytes. |
The following read-only properties provide information about cache efficiency:
Property | Description |
|---|---|
| Total number of cache accesses. |
| Number of cache hits. |
| Number of cache hits divided by total number of cache accesses. |
| Number of times out of date entries were invalidated. |
| Ratio of cache entries to maximum cache entries. |
| Amount of memory in bytes used by cache entries (includes keys). |
