TransactionCacheEntry

Perform a transactional cache insertion, returning a FastlyBody instance for providing the cached object itself.

This method should only be called when TransactionCacheEntry.state().mustInsertOrUpdate() is true; otherwise, an error will be thrown when attempting to perform the insertion.

Perform a transactional cache insertion, returning a FastlyBody instance for providing the cached object itself, and a CacheEntry instance which can be used to stream out the newly-inserted cache item.

For the insertion to complete successfully, the object must be written into the returned FastlyBody instance, and then FastlyBody.prototype.close must be called. If FastlyBody.prototype.close does not get called, the insertion is considered incomplete, and any concurrent lookups that may be reading from the object as it is streamed into the cache may encounter a streaming error.