Example¶

In the example below, suppose there is a cache hit and the cache returns a vconnection that enables you to read the document from cache. To do this, you need to prepare a buffer (cache_bufp) to hold the document; meanwhile, use TSVConnCachedObjectSizeGet to find out the actual size of the document (content_length). Then, issue TSVConnRead to read the document with the total data length required as content_length. Assume the following data:

TSIOBuffer       cache_bufp = TSIOBufferCreate ();
TSIOBufferReader cache_readerp = TSIOBufferReaderAlloc (out_bufp);
TSVConn          cache_vconnp = NULL;
TSVIO            cache_vio = NULL;
int               content_length = 0;

In the TS_CACHE_OPEN_READ handler:

cache_vconnp = (TSVConn) data;
    TSVConnCachedObjectSizeGet (cache_vconnp, &content_length);
    cache_vio = TSVConnRead (cache_vconn, contp, cache_bufp, content_length);

In the TS_EVENT_VCONN_READ_READY handler:

(usual VCONN_READ_READY handler logic)
int nbytes = TSVIONBytesGet (cache_vio);
int ntodo  = TSVIONTodoGet (cache_vio);
int ndone  = TSVIONDoneGet (cache_vio);
(consume data in cache_bufp)
TSVIOReenable (cache_vio);

Do not try to get continuations or VIOs from TSVConn objects for cache vconnections. Also note that the following APIs can only be used on transformation vconnections and must not be used on cache vconnections or net vconnections:

• TSVConnWriteVIOGet
• TSVConnReadVIOGet
• TSVConnClosedGet

APIs such as TSVConnRead, TSVConnWrite, TSVConnClose, TSVConnAbort, and TSVConnShutdown can be used on any kind of vconnections.

When you are finished:

TSCacheKeyDestroy (key);