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Mercurial > core / lisp/ffi/rocksdb/compaction.lisp

changeset 698: 96958d3eb5b0
parent: 57813b8ee029
author: Richard Westhaver <ellis@rwest.io>
date: Fri, 04 Oct 2024 22:04:59 -0400
permissions: -rw-r--r--
description: fixes 
     1 ;;; rocksdb/compaction.lisp --- RocksDB Compaction
     2 
     3 ;; RocksDB Lisp Compaction Filter API
     4 
     5 ;;; Commentary:
     6 
     7 ;; compaction filters are like custom GC rules for the database. compactions
     8 ;; run in the background and can be configured via the column-family-options
     9 ;; or compactionfilterfactory API.
    10 
    11 ;; ref: https://github.com/facebook/rocksdb/wiki/Compaction-Filter
    12 
    13 #|
    14 * RocksDB snapshots do not guarantee to preserve the state of the DB in the
    15 presence of CompactionFilter. Data seen from a snapshot might disappear after
    16 a table file created with a `CompactionFilter` is installed. If you use
    17 snapshots, think twice about whether you want to use `CompactionFilter` and
    18 whether you are using it in a safe way.
    19 
    20 * If multithreaded compaction is being used *and* a single CompactionFilter
    21 instance was supplied via Options::compaction_filter, CompactionFilter
    22 methods may be called from different threads concurrently.  The application
    23 must ensure that such calls are thread-safe. If the CompactionFilter was
    24 created by a factory, then it will only ever be used by a single thread that
    25 is doing the table file creation, and this call does not need to be
    26 thread-safe.  However, multiple filters may be in existence and operating
    27 concurrently.
    28 
    29 * The key passed to the filtering methods includes the timestamp if
    30 user-defined timestamps are enabled.
    31 
    32 * Exceptions MUST NOT propagate out of overridden functions into RocksDB,
    33 because RocksDB is not exception-safe. This could cause undefined behavior
    34 including data loss, unreported corruption, deadlocks, and more.
    35 |#
    36 ;;; Code:
    37 (in-package :rocksdb)
    38 
    39 (define-alien-type rocksdb-filter-function
    40   (function unsigned-char
    41             (* t)
    42             int
    43             c-string
    44             size-t
    45             c-string
    46             size-t
    47             (* (array unsigned-char))
    48             (* size-t)
    49             (* unsigned-char)))
    50 
    51 (define-alien-type rocksdb-create-compaction-filter-function
    52     (function (* rocksdb-compactionfilter)
    53               (* t)
    54               (* rocksdb-compactionfiltercontext)))
    55 
    56 (define-alien-routine rocksdb-compactionfilter-create (* rocksdb-compactionfilter)
    57   (state (* t))
    58   (destructor (* rocksdb-destructor-function))
    59   (filter (* rocksdb-filter-function))
    60   (name (* rocksdb-name-function)))
    61 
    62 (define-alien-routine rocksdb-compactionfilter-set-ignore-snapshots void
    63   (self (* rocksdb-compactionfilter)) (val unsigned-char))
    64 
    65 (define-alien-routine rocksdb-compactionfilter-destroy void
    66   (self (* rocksdb-compactionfilter)))
    67 
    68 ;;; Compaction Filter Context
    69 (define-alien-routine rocksdb-compactionfiltercontext-is-full-compaction unsigned-char
    70   (context (* rocksdb-compactionfiltercontext)))
    71 
    72 (define-alien-routine rocksdb-compactionfiltercontext-is-manual-compaction unsigned-char
    73   (context (* rocksdb-compactionfiltercontext)))
    74 
    75 ;;; Compaction Filter Factory
    76 (define-alien-routine rocksdb-compactionfilterfactory-create (* rocksdb-compactionfilterfactory)
    77   (state (* t))
    78   (destructor (* rocksdb-destructor-function))
    79   (creator (* rocksdb-create-compaction-filter-function))
    80   (name (* rocksdb-name-function)))
    81 
    82 (define-alien-routine rocksdb-compacitonfilterfactory-destroy void
    83   (factory (* rocksdb-compactionfilterfactory)))
    84 
    85 (define-alien-callable rocksdb-filter-never unsigned-char
    86     ((state (* t))
    87      (level int)
    88      (key (array unsigned-char))
    89      (key-length size-t)
    90      (existing-val (array unsigned-char))
    91      (existing-val-length size-t)
    92      (new-val (* (array unsigned-char)))
    93      (new-val-length (* size-t))
    94      (value-changed (* unsigned-char)))
    95   (declare (ignore state level key key-length existing-val existing-val-length new-val new-val-length value-changed))
    96   0)
    97 
    98 (define-alien-callable rocksdb-create-compaction-filter-never (* rocksdb-compactionfilter)
    99     ((state (* t))
   100      (context (* rocksdb-compactionfiltercontext)))
   101   (rocksdb-compactionfilter-create
   102    state
   103    (alien-sap (alien-callable-function 'rocksdb-destructor))
   104    (alien-sap (alien-callable-function 'rocksdb-filter-never))
   105    context))