Operations on Event Caches

Supported Event Cache Operations

• expireCache – Remove events from the current bucket that are older than a certain number of seconds.

  Syntax: expireCache(events, seconds)

  Type: The first argument must name an event cache variable. The second argument must be an integer. The function returns the event cache.

  Example: expireCache(events, 50)

• insertCache – Insert a record value into an event cache.

  Syntax: insertCache(events, record)

  Type: The first argument must name an event cache variable. The argument must be a record type. The function returns the record inserted.

  Example: insertCache(events, inputStream)

• keyCache – Select the current bucket in an event cache. Normally, the current input record selects the active bucket. You might want to change the current active bucket in some cases. For example, during the evaluation of the debugging expressions, there is no current input record and thus no bucket is set by default. The only way to set the bucket then is to do it manually using this function.

  Syntax: keyCache(events, event)

  Type: The first argument must name an event cache variable. The second argument must be a record type. The function returns the same record.

  Example: keyCache(ec1, rec)

• getCache – Returns the row specified by a given index from the current bucket in the event cache. This index is 0 based. The function takes an integer as its argument, and the function returns a row. Specifying an invalid index parameter will result in the generation of a bad record.

  Syntax: getCache(cacheName, index)

  Type: The first argument must name an event cache variable. The second argument must be an integer specifying the row to retrieve. The function returns the specified row of the cache.

  Example: getCache(tradesCache, 3)

• deleteCache – Returns the row specified by a given index from the current bucket in the event cache. This index is 0 based. The function takes an integer as its argument, and the function returns a row. Specifying an invalid index parameter will result in the generation of a bad record.

  Syntax: deleteCache(cacheName, index)

  Type: The first argument must name an event cache variable. The second argument must be an integer specifying the row to delete. The function deletes the specified row; it does not return any output.

  Example: deleteCache(tradesCache, 0)

• cacheSize – Returns the size of the current bucket in the event cache.

  Syntax: cacheSize(cacheName)

  Type: This function takes an argument of the name of the event cache variable. It then returns an integer.

  Example: cacheSize(tradesCache)