;;; registry.el --- Track and remember data items by various fields
-;; Copyright (C) 2011-2012 Free Software Foundation, Inc.
+;; Copyright (C) 2011-2015 Free Software Foundation, Inc.
;; Author: Teodor Zlatanov <tzz@lifelogs.com>
;; Keywords: data
;; This library provides a general-purpose EIEIO-based registry
;; database with persistence, initialized with these fields:
-;; version: a float, 0.1 currently (don't change it)
+;; version: a float
-;; max-hard: an integer, default 5000000
+;; max-size: an integer, default most-positive-fixnum
-;; max-soft: an integer, default 50000
+;; prune-factor: a float between 0 and 1, default 0.1
;; precious: a list of symbols
;; Note that whether a field has one or many pieces of data, the data
;; is always a list of values.
-;; The user decides which fields are "precious", F2 for example. At
-;; PRUNE TIME (when the :prune-function is called), the registry will
-;; trim any entries without the F2 field until the size is :max-soft
-;; or less. No entries with the F2 field will be removed at PRUNE
-;; TIME.
+;; The user decides which fields are "precious", F2 for example. When
+;; the registry is pruned, any entries without the F2 field will be
+;; removed until the size is :max-size * :prune-factor _less_ than the
+;; maximum database size. No entries with the F2 field will be removed
+;; at PRUNE TIME, which means it may not be possible to prune back all
+;; the way to the target size.
-;; When an entry is inserted, the registry will reject new entries
-;; if they bring it over the max-hard limit, even if they have the F2
+;; When an entry is inserted, the registry will reject new entries if
+;; they bring it over the :max-size limit, even if they have the F2
;; field.
;; The user decides which fields are "tracked", F1 for example. Any
(error
"eieio not found in `load-path' or gnus-fallback-lib/ directory.")))
+(eval-when-compile
+ (unless (fboundp 'cl-remf)
+ (defalias 'cl-remf 'remf)
+ (defalias 'cl-loop 'loop)
+ (defalias 'cl-subseq 'subseq)))
+
+;; The version number needs to be kept outside of the class definition
+;; itself. The persistent-save process does *not* write to file any
+;; slot values that are equal to the default :initform value. If a
+;; database object is at the most recent version, therefore, its
+;; version number will not be written to file. That makes it
+;; difficult to know when a database needs to be upgraded.
+(defvar registry-db-version 0.2
+ "The current version of the registry format.")
+
+(eval `
(defclass registry-db (eieio-persistent)
((version :initarg :version
- :initform 0.1
- :type float
- :custom float
+ :initform nil
+ :type (or null float)
:documentation "The registry version.")
- (max-hard :initarg :max-hard
- :initform 5000000
- :type integer
- :custom integer
- :documentation "Never accept more than this many elements.")
- (max-soft :initarg :max-soft
- :initform 50000
+ (max-size :initarg :max-size
+ ;; EIEIO's :initform is not 100% compatible with CLOS in
+ ;; that if the form is an atom, it assumes it's constant
+ ;; value rather than an expression, so in order to get the value
+ ;; of `most-positive-fixnum', we need to use an
+ ;; expression that's not just a symbol.
+ :initform ,(symbol-value 'most-positive-fixnum)
:type integer
:custom integer
- :documentation "Prune as much as possible to get to this size.")
+ :documentation "The maximum number of registry entries.")
(prune-factor
:initarg :prune-factor
:initform 0.1
:type float
:custom float
- :documentation "At the max-hard limit, prune size * this entries.")
+ :documentation "Prune to \(:max-size * :prune-factor\) less
+ than the :max-size limit. Should be a float between 0 and 1.")
(tracked :initarg :tracked
:initform nil
:type t
(data :initarg :data
:type hash-table
:documentation "The data hashtable.")))
-
-(eval-and-compile
- (defmethod initialize-instance :AFTER ((this registry-db) slots)
- "Set value of data slot of THIS after initialization."
- (with-slots (data tracker) this
- (unless (member :data slots)
- (setq data
- (make-hash-table :size 10000 :rehash-size 2.0 :test 'equal)))
- (unless (member :tracker slots)
- (setq tracker (make-hash-table :size 100 :rehash-size 2.0)))))
-
- (defmethod registry-lookup ((db registry-db) keys)
- "Search for KEYS in the registry-db THIS.
+)
+
+(defmethod initialize-instance :BEFORE ((this registry-db) slots)
+ "Check whether a registry object needs to be upgraded."
+ ;; Hardcoded upgrade routines. Version 0.1 to 0.2 requires the
+ ;; :max-soft slot to disappear, and the :max-hard slot to be renamed
+ ;; :max-size.
+ (let ((current-version
+ (and (plist-member slots :version)
+ (plist-get slots :version))))
+ (when (or (null current-version)
+ (eql current-version 0.1))
+ (setq slots
+ (plist-put slots :max-size (plist-get slots :max-hard)))
+ (setq slots
+ (plist-put slots :version registry-db-version))
+ (cl-remf slots :max-hard)
+ (cl-remf slots :max-soft))))
+
+(defmethod initialize-instance :AFTER ((this registry-db) slots)
+ "Set value of data slot of THIS after initialization."
+ (with-slots (data tracker) this
+ (unless (member :data slots)
+ (setq data
+ (make-hash-table :size 10000 :rehash-size 2.0 :test 'equal)))
+ (unless (member :tracker slots)
+ (setq tracker (make-hash-table :size 100 :rehash-size 2.0)))))
+
+(defmethod registry-lookup ((db registry-db) keys)
+ "Search for KEYS in the registry-db THIS.
Returns an alist of the key followed by the entry in a list, not a cons cell."
- (let ((data (oref db :data)))
- (delq nil
- (mapcar
- (lambda (k)
- (when (gethash k data)
- (list k (gethash k data))))
- keys))))
-
- (defmethod registry-lookup-breaks-before-lexbind ((db registry-db) keys)
- "Search for KEYS in the registry-db THIS.
+ (let ((data (oref db data)))
+ (delq nil
+ (mapcar
+ (lambda (k)
+ (when (gethash k data)
+ (list k (gethash k data))))
+ keys))))
+
+(defmethod registry-lookup-breaks-before-lexbind ((db registry-db) keys)
+ "Search for KEYS in the registry-db THIS.
Returns an alist of the key followed by the entry in a list, not a cons cell."
- (let ((data (oref db :data)))
- (delq nil
- (loop for key in keys
- when (gethash key data)
- collect (list key (gethash key data))))))
-
- (defmethod registry-lookup-secondary ((db registry-db) tracksym
- &optional create)
- "Search for TRACKSYM in the registry-db THIS.
+ (let ((data (oref db data)))
+ (delq nil
+ (loop for key in keys
+ when (gethash key data)
+ collect (list key (gethash key data))))))
+
+(defmethod registry-lookup-secondary ((db registry-db) tracksym
+ &optional create)
+ "Search for TRACKSYM in the registry-db THIS.
When CREATE is not nil, create the secondary index hashtable if needed."
- (let ((h (gethash tracksym (oref db :tracker))))
- (if h
- h
- (when create
- (puthash tracksym
- (make-hash-table :size 800 :rehash-size 2.0 :test 'equal)
- (oref db :tracker))
- (gethash tracksym (oref db :tracker))))))
-
- (defmethod registry-lookup-secondary-value ((db registry-db) tracksym val
- &optional set)
- "Search for TRACKSYM with value VAL in the registry-db THIS.
+ (let ((h (gethash tracksym (oref db :tracker))))
+ (if h
+ h
+ (when create
+ (puthash tracksym
+ (make-hash-table :size 800 :rehash-size 2.0 :test 'equal)
+ (oref db tracker))
+ (gethash tracksym (oref db tracker))))))
+
+(defmethod registry-lookup-secondary-value ((db registry-db) tracksym val
+ &optional set)
+ "Search for TRACKSYM with value VAL in the registry-db THIS.
When SET is not nil, set it for VAL (use t for an empty list)."
- ;; either we're asked for creation or there should be an existing index
- (when (or set (registry-lookup-secondary db tracksym))
- ;; set the entry if requested,
- (when set
- (puthash val (if (eq t set) '() set)
- (registry-lookup-secondary db tracksym t)))
- (gethash val (registry-lookup-secondary db tracksym)))))
+ ;; either we're asked for creation or there should be an existing index
+ (when (or set (registry-lookup-secondary db tracksym))
+ ;; set the entry if requested,
+ (when set
+ (puthash val (if (eq t set) '() set)
+ (registry-lookup-secondary db tracksym t)))
+ (gethash val (registry-lookup-secondary db tracksym))))
(defun registry--match (mode entry check-list)
;; for all members
(or found
(registry--match mode entry (cdr-safe check-list))))))
-(eval-and-compile
- (defmethod registry-search ((db registry-db) &rest spec)
- "Search for SPEC across the registry-db THIS.
-For example calling with :member '(a 1 2) will match entry '((a 3 1)).
+(defmethod registry-search ((db registry-db) &rest spec)
+ "Search for SPEC across the registry-db THIS.
+For example calling with :member \\='(a 1 2) will match entry \\='((a 3 1)).
Calling with :all t (any non-nil value) will match all.
-Calling with :regex '\(a \"h.llo\") will match entry '((a \"hullo\" \"bye\").
+Calling with :regex \\='\(a \"h.llo\") will match entry \\='((a \"hullo\" \"bye\").
The test order is to check :all first, then :member, then :regex."
- (when db
- (let ((all (plist-get spec :all))
- (member (plist-get spec :member))
- (regex (plist-get spec :regex)))
- (loop for k being the hash-keys of (oref db :data)
- using (hash-values v)
- when (or
- ;; :all non-nil returns all
- all
- ;; member matching
- (and member (registry--match :member v member))
- ;; regex matching
- (and regex (registry--match :regex v regex)))
- collect k))))
-
- (defmethod registry-delete ((db registry-db) keys assert &rest spec)
- "Delete KEYS from the registry-db THIS.
+ (when db
+ (let ((all (plist-get spec :all))
+ (member (plist-get spec :member))
+ (regex (plist-get spec :regex)))
+ (loop for k being the hash-keys of (oref db data)
+ using (hash-values v)
+ when (or
+ ;; :all non-nil returns all
+ all
+ ;; member matching
+ (and member (registry--match :member v member))
+ ;; regex matching
+ (and regex (registry--match :regex v regex)))
+ collect k))))
+
+(defmethod registry-delete ((db registry-db) keys assert &rest spec)
+ "Delete KEYS from the registry-db THIS.
If KEYS is nil, use SPEC to do a search.
Updates the secondary ('tracked') indices as well.
With assert non-nil, errors out if the key does not exist already."
- (let* ((data (oref db :data))
- (keys (or keys
- (apply 'registry-search db spec)))
- (tracked (oref db :tracked)))
-
- (dolist (key keys)
- (let ((entry (gethash key data)))
- (when assert
- (assert entry nil
- "Key %s does not exists in database" key))
- ;; clean entry from the secondary indices
- (dolist (tr tracked)
- ;; is this tracked symbol indexed?
- (when (registry-lookup-secondary db tr)
- ;; for every value in the entry under that key...
- (dolist (val (cdr-safe (assq tr entry)))
- (let* ((value-keys (registry-lookup-secondary-value
- db tr val)))
- (when (member key value-keys)
- ;; override the previous value
- (registry-lookup-secondary-value
- db tr val
- ;; with the indexed keys MINUS the current key
- ;; (we pass t when the list is empty)
- (or (delete key value-keys) t)))))))
- (remhash key data)))
- keys))
-
- (defmethod registry-full ((db registry-db))
- "Checks if registry-db THIS is full."
- (>= (registry-size db)
- (oref db :max-hard)))
-
- (defmethod registry-insert ((db registry-db) key entry)
- "Insert ENTRY under KEY into the registry-db THIS.
+ (let* ((data (oref db data))
+ (keys (or keys
+ (apply 'registry-search db spec)))
+ (tracked (oref db tracked)))
+
+ (dolist (key keys)
+ (let ((entry (gethash key data)))
+ (when assert
+ (assert entry nil
+ "Key %s does not exist in database" key))
+ ;; clean entry from the secondary indices
+ (dolist (tr tracked)
+ ;; is this tracked symbol indexed?
+ (when (registry-lookup-secondary db tr)
+ ;; for every value in the entry under that key...
+ (dolist (val (cdr-safe (assq tr entry)))
+ (let* ((value-keys (registry-lookup-secondary-value
+ db tr val)))
+ (when (member key value-keys)
+ ;; override the previous value
+ (registry-lookup-secondary-value
+ db tr val
+ ;; with the indexed keys MINUS the current key
+ ;; (we pass t when the list is empty)
+ (or (delete key value-keys) t)))))))
+ (remhash key data)))
+ keys))
+
+(defmethod registry-size ((db registry-db))
+ "Returns the size of the registry-db object THIS.
+This is the key count of the `data' slot."
+ (hash-table-count (oref db data)))
+
+(defmethod registry-full ((db registry-db))
+ "Checks if registry-db THIS is full."
+ (>= (registry-size db)
+ (oref db max-size)))
+
+(defmethod registry-insert ((db registry-db) key entry)
+ "Insert ENTRY under KEY into the registry-db THIS.
Updates the secondary ('tracked') indices as well.
Errors out if the key exists already."
- (assert (not (gethash key (oref db :data))) nil
- "Key already exists in database")
-
- (assert (not (registry-full db))
- nil
- "registry max-hard size limit reached")
-
- ;; store the entry
- (puthash key entry (oref db :data))
-
- ;; store the secondary indices
- (dolist (tr (oref db :tracked))
- ;; for every value in the entry under that key...
- (dolist (val (cdr-safe (assq tr entry)))
- (let* ((value-keys (registry-lookup-secondary-value db tr val)))
- (pushnew key value-keys :test 'equal)
- (registry-lookup-secondary-value db tr val value-keys))))
- entry)
-
- (defmethod registry-reindex ((db registry-db))
- "Rebuild the secondary indices of registry-db THIS."
- (let ((count 0)
- (expected (* (length (oref db :tracked)) (registry-size db))))
- (dolist (tr (oref db :tracked))
- (let (values)
- (maphash
- (lambda (key v)
- (incf count)
- (when (and (< 0 expected)
- (= 0 (mod count 1000)))
- (message "reindexing: %d of %d (%.2f%%)"
- count expected (/ (* 100 count) expected)))
- (dolist (val (cdr-safe (assq tr v)))
- (let* ((value-keys (registry-lookup-secondary-value db tr val)))
- (push key value-keys)
- (registry-lookup-secondary-value db tr val value-keys))))
- (oref db :data))))))
-
- (defmethod registry-size ((db registry-db))
- "Returns the size of the registry-db object THIS.
-This is the key count of the :data slot."
- (hash-table-count (oref db :data)))
-
- (defmethod registry-prune ((db registry-db) &optional sortfun)
- "Prunes the registry-db object THIS.
-Removes only entries without the :precious keys if it can,
-then removes oldest entries first.
-Returns the number of deleted entries.
-If SORTFUN is given, tries to keep entries that sort *higher*.
-SORTFUN is passed only the two keys so it must look them up directly."
- (dolist (collector '(registry-prune-soft-candidates
- registry-prune-hard-candidates))
- (let* ((size (registry-size db))
- (collected (funcall collector db))
- (limit (nth 0 collected))
- (candidates (nth 1 collected))
- ;; sort the candidates if SORTFUN was given
- (candidates (if sortfun (sort candidates sortfun) candidates))
- (candidates-count (length candidates))
- ;; are we over max-soft?
- (prune-needed (> size limit)))
-
- ;; while we have more candidates than we need to remove...
- (while (and (> candidates-count (- size limit)) candidates)
- (decf candidates-count)
- (setq candidates (cdr candidates)))
-
- (registry-delete db candidates nil)
- (length candidates))))
-
- (defmethod registry-prune-soft-candidates ((db registry-db))
- "Collects pruning candidates from the registry-db object THIS.
-Proposes only entries without the :precious keys."
- (let* ((precious (oref db :precious))
- (precious-p (lambda (entry-key)
- (cdr (memq (car entry-key) precious))))
- (data (oref db :data))
- (limit (oref db :max-soft))
- (candidates (loop for k being the hash-keys of data
- using (hash-values v)
- when (notany precious-p v)
- collect k)))
- (list limit candidates)))
-
- (defmethod registry-prune-hard-candidates ((db registry-db))
- "Collects pruning candidates from the registry-db object THIS.
-Proposes any entries over the max-hard limit minus size * prune-factor."
- (let* ((data (oref db :data))
- ;; prune to (size * prune-factor) below the max-hard limit so
- ;; we're not pruning all the time
- (limit (max 0 (- (oref db :max-hard)
- (* (registry-size db) (oref db :prune-factor)))))
- (candidates (loop for k being the hash-keys of data
- collect k)))
- (list limit candidates))))
+ (assert (not (gethash key (oref db data))) nil
+ "Key already exists in database")
+
+ (assert (not (registry-full db))
+ nil
+ "registry max-size limit reached")
+
+ ;; store the entry
+ (puthash key entry (oref db data))
+
+ ;; store the secondary indices
+ (dolist (tr (oref db tracked))
+ ;; for every value in the entry under that key...
+ (dolist (val (cdr-safe (assq tr entry)))
+ (let* ((value-keys (registry-lookup-secondary-value db tr val)))
+ (pushnew key value-keys :test 'equal)
+ (registry-lookup-secondary-value db tr val value-keys))))
+ entry)
+
+(defmethod registry-reindex ((db registry-db))
+ "Rebuild the secondary indices of registry-db THIS."
+ (let ((count 0)
+ (expected (* (length (oref db tracked)) (registry-size db))))
+ (dolist (tr (oref db tracked))
+ (let (values)
+ (maphash
+ (lambda (key v)
+ (incf count)
+ (when (and (< 0 expected)
+ (= 0 (mod count 1000)))
+ (message "reindexing: %d of %d (%.2f%%)"
+ count expected (/ (* 100.0 count) expected)))
+ (dolist (val (cdr-safe (assq tr v)))
+ (let* ((value-keys (registry-lookup-secondary-value db tr val)))
+ (push key value-keys)
+ (registry-lookup-secondary-value db tr val value-keys))))
+ (oref db data))))))
+
+(defmethod registry-prune ((db registry-db) &optional sortfunc)
+ "Prunes the registry-db object DB.
+
+Attempts to prune the number of entries down to \(*
+:max-size :prune-factor\) less than the max-size limit, so
+pruning doesn't need to happen on every save. Removes only
+entries without the :precious keys, so it may not be possible to
+reach the target limit.
+
+Entries to be pruned are first sorted using SORTFUNC. Entries
+from the front of the list are deleted first.
+
+Returns the number of deleted entries."
+ (let ((size (registry-size db))
+ (target-size
+ (floor (- (oref db max-size)
+ (* (oref db max-size)
+ (oref db prune-factor)))))
+ candidates)
+ (if (registry-full db)
+ (progn
+ (setq candidates
+ (registry-collect-prune-candidates
+ db (- size target-size) sortfunc))
+ (length (registry-delete db candidates nil)))
+ 0)))
+
+(defmethod registry-collect-prune-candidates ((db registry-db) limit sortfunc)
+ "Collects pruning candidates from the registry-db object DB.
+
+Proposes only entries without the :precious keys, and attempts to
+return LIMIT such candidates. If SORTFUNC is provided, sort
+entries first and return candidates from beginning of list."
+ (let* ((precious (oref db precious))
+ (precious-p (lambda (entry-key)
+ (cdr (memq (car entry-key) precious))))
+ (data (oref db data))
+ (candidates (cl-loop for k being the hash-keys of data
+ using (hash-values v)
+ when (notany precious-p v)
+ collect (cons k v))))
+ ;; We want the full entries for sorting, but should only return a
+ ;; list of entry keys.
+ (when sortfunc
+ (setq candidates (sort candidates sortfunc)))
+ (cl-subseq (mapcar #'car candidates) 0 (min limit (length candidates)))))
(provide 'registry)
;;; registry.el ends here