Callback to perform any validity checks before the entry should be used.
Called before onCacheEntryAvailable callback, depending on the result it
may be called more then one time.
This callback is ensured to be called on the same thread on which asyncOpenURI
has been called, unless nsICacheStorage.CHECK_MULTITHREADED flag has been specified.
In that case this callback can be invoked on any thread, usually it is the cache I/O
or cache management thread.
IMPORTANT NOTE:
This callback may be invoked sooner then respective asyncOpenURI call exits.
| aEntry | An entry to examine. Consumer has a chance to decide whether the entry is valid or not. |
| aApplicationCache | Optional, application cache the entry has been found in, if any. |
| State of the entry, see the constants just above. |
Callback giving actual result of asyncOpenURI. It may give consumer the cache
entry or a failure result when it’s not possible to open it from some reason.
This callback is ensured to be called on the same thread on which asyncOpenURI
has been called.
IMPORTANT NOTE:
This callback may be invoked sooner then respective asyncOpenURI call exits.
| aEntry | The entry bound to the originally requested URI. May be null when loading from a particular application cache and the URI has not been found in that application cache. |
| aNew | Whether no data so far has been stored for this entry, i.e. reading it will just fail. When aNew is true, a server request should be made and data stored to this new entry. |
| aApplicationCache | When an entry had been found in an application cache, this is the given application cache. It should be associated with the loading channel. |
| aResult | Result of the request. This may be a failure only when one of these issues occur: - the cache storage service could not be started due to some unexpected faulure - there is not enough disk space to create new entries - cache entry was not found in a given application cache |
State of the entry determined by onCacheEntryCheck.
ENTRY_WANTED - the consumer is interested in the entry, we will pass it.
RECHECK_AFTER_WRITE_FINISHED - the consumer cannot use the entry while data is
still being written and wants to check it again after the current write is
finished. This actually prevents concurrent read/write and is used with
non-resumable HTTP responses.
ENTRY_NEEDS_REVALIDATION - entry needs to be revalidated first with origin server,
this means the loading channel will decide whether to use the entry content
as is after it gets a positive response from the server about validity of the
content ; when a new content needs to be loaded from the server, the loading
channel opens a new entry with OPEN_TRUNCATE flag which dooms the one
this check has been made for.
ENTRY_NOT_WANTED - the consumer is not interested in the entry, we will not pass it.