package index
Library
Module
Module type
Parameter
Class
Class type
Parameters
module K : Index.Key.S
module V : Index.Value.S
module C : Index.Cache.S
Signature
type key = K.t
The type for keys.
type value = V.t
The type for values.
val empty_cache : unit -> cache
Construct a new empty cache of index instances.
val v :
?flush_callback:(unit -> unit) ->
?cache:cache ->
?fresh:bool ->
?readonly:bool ->
?throttle:[ `Overcommit_memory | `Block_writes ] ->
?lru_size:int ->
log_size:int ->
string ->
t
The constructor for indexes.
val clear : t -> unit
clear t
clears t
so that there are no more bindings in it.
replace t k v
binds k
to v
in t
, replacing any existing binding of k
.
If overcommit
is true, the operation does not triger a merge, even if the caches are full. By default overcommit
is false.
filter t p
removes all the bindings (k, v) that do not satisfy p
. This operation is costly and blocking.
Iterates over the index bindings. Limitations:
- Order is not specified.
- In case of recent replacements of existing values (since the last merge), this will hit both the new and old bindings.
- May not observe recent concurrent updates to the index by other processes.
val flush : ?no_callback:unit -> ?with_fsync:bool -> t -> unit
Flushes all internal buffers of the IO
instances.
- Passing
~no_callback:()
disables calling theflush_callback
passed tov
. - If
with_fsync
istrue
, this also flushes the OS caches for eachIO
instance.
val close : ?immediately:unit -> t -> unit
Closes all resources used by t
, flushing any internal buffers in the instance.
If immediately
is passed, this operation will abort any ongoing background processes. This guarantees not to corrupt the store, but may require additional work to be done on the next startup.
val sync : t -> unit
sync t
syncs a read-only index with the files on disk. Raises RW_not_allowed
if called by a read-write index.
val is_merging : t -> bool
is_merging t
returns true if t
is running a merge. Raises RO_not_allowed
if called by a read-only index.
val merge : t -> unit
merge t
forces a merge for t
.
If there is no merge running, this operation is non-blocking, i.e. it returns immediately, with the merge running concurrently.
If a merge is running already, this operation blocks until the previous merge is complete. It then launches a merge (which runs concurrently) and returns.
val try_merge : t -> unit
try_merge
is like merge
but is a no-op if the number of entries in the write-ahead log is smaller than log_size
.
module Checks : sig ... end
Offline fsck
-like utility for checking the integrity of Index stores built using this module.