scan_apply function

Iterate over keys using SCAN

Support for iterating with SCAN. Note that this will generalise soon to support collecting output, SSCAN and other variants, etc.

scan_apply(
  con,
  callback,
  pattern = NULL,
  ...,
  count = NULL,
  type = "SCAN",
  key = NULL
)

scan_del(con, pattern, count = NULL, type = "SCAN", key = NULL)

scan_find(con, pattern, count = NULL, type = "SCAN", key = NULL)

Arguments

• con: A redis_api object
• callback: Function that takes a character vector of keys and does something useful to it. con$DEL is one option here to delete keys that match a pattern. Unlike R's *apply functions, callback is called for its side effects and its return values will be ignored.
• pattern: Optional pattern to use.
• ...: additional arguments passed through to callback. Note that if used, pattern must be provided (at least as NULL).
• count: Optional step size (default is Redis' default which is 10)
• type: Type of SCAN to run. Options are "SCAN" (the default), "HSCAN" (scan through keys of a hash), "SSCAN" (scan through elements of a set) and "ZSCAN" (scan though elements of a sorted set). If type is not "SCAN", then key must be provided. HSCAN and ZSCAN currently do not work usefully.
• key: Key to use when running a hash, set or sorted set scan.

Details

The functions scan_del and scan_find are example functions that delete and find all keys corresponding to a given pattern.