func getCasidForCachedItem(cache ybc.Cacher, key []byte) (casid uint64, cacheMiss, ok bool) {
item, err := cache.GetItem(key)
if err != nil {
if err == ybc.ErrCacheMiss {
cacheMiss = true
return
}
log.Fatalf("Unexpected error returned from Cache.GetItem() for key=[%s]: [%s]", key, err)
}
// do not use defer item.Close() for performance reasons
var buf [casidSize]byte
n, err := item.Read(buf[:])
item.Close()
if err != nil {
log.Printf("Error when reading casid for the item: [%s]", err)
return
}
if n != len(buf) {
log.Printf("Unexpected result returned from ybc.Item.Read(): %d. Expected %d", n, len(buf))
return
}
casid = binary.LittleEndian.Uint64(buf[:])
ok = true
return
}
func cGetFromCache(cache ybc.Cacher, key []byte, etag *uint64) (item *ybc.Item, err error) {
item, err = cache.GetItem(key)
if err == ybc.ErrCacheMiss {
return
}
if err != nil {
log.Fatalf("Unexpected error returned from Cache.GetItem() for key=[%s]: [%s]", key, err)
}
defer func() {
if err != nil {
item.Close()
}
}()
etagOld := *etag
if err = binaryRead(item, etag, "etag"); err != nil {
return
}
if etagOld == *etag {
item.Close()
item = nil
return
}
return
}
func cachedItemExists(cache ybc.Cacher, key []byte) bool {
item, err := cache.GetItem(key)
if err == ybc.ErrCacheMiss {
return false
}
if err != nil {
log.Fatalf("Unexpected error returned from Cacher.GetItem(): [%s]", err)
}
item.Close()
return true
}
func getItemAndWriteResponse(w *bufio.Writer, cache ybc.Cacher, key []byte, cas bool, scratchBuf *[]byte) bool {
item, err := cache.GetItem(key)
if err != nil {
if err == ybc.ErrCacheMiss {
return true
}
log.Fatalf("Unexpected error returned by cache.GetItem(key=[%s]): [%s]", key, err)
}
defer item.Close()
return writeGetResponse(w, key, item, cas, scratchBuf)
}
func getItemAndWriteResponse(w *bufio.Writer, cache ybc.Cacher, key []byte, shouldWriteCasid bool, scratchBuf *[]byte) bool {
item, err := cache.GetItem(key)
if err != nil {
if err == ybc.ErrCacheMiss {
return true
}
log.Fatalf("Unexpected error returned by cache.GetItem(key=[%s]): [%s]", key, err)
}
// do not use defer item.Close() for performance reasons
ok := writeGetResponse(w, key, item, shouldWriteCasid, scratchBuf)
item.Close()
return ok
}
func processCgetCmd(c *bufio.ReadWriter, cache ybc.Cacher, line []byte, scratchBuf *[]byte) bool {
n := -1
key := nextToken(line, &n, "key")
if key == nil {
return false
}
casid, ok := parseUint64Token(line, &n, "casid")
if !ok {
return false
}
if !expectEof(line, n) {
return false
}
item, err := cache.GetItem(key)
if err == ybc.ErrCacheMiss {
return writeStr(c.Writer, strEndCrLf)
}
if err != nil {
log.Fatalf("Unexpected error returned: [%s]", err)
}
// do not use defer item.Close() for performance reasons
isModified, ok := checkAndUpdateCasid(item, &casid)
if !ok {
item.Close()
return false
}
if !isModified {
item.Close()
return writeStr(c.Writer, strNotModifiedCrLf)
}
ok = writeGetResponseWithEof(c.Writer, key, item, scratchBuf)
item.Close()
return ok
}
