Grooming + examples.

src/dodb.cl

@@ -17,63 +17,65 @@
 (alias ln osicat:make-link)
 (alias ls osicat:list-directory)
 
+(defun to-upper-case (some-string)
+  (format nil "~@:(~a~)" some-string))
+
+; Example: 18 -> 000000000000018.data
+(defun number->filename (number)
+  (format nil "~15,'0D.data" number))
+
+; Example: "vehicle" "color" object -> (vehicle-color object) -> "Red"
+(defun get-object-attribute (struct-name attribute-name object)
+  (funcall ; example: call function "VEHICLE-COLOR"
+    (find-symbol (to-upper-case
+      (concatenate 'string struct-name "-" attribute-name)))
+    object))
+
 ; index = 1-1
 ; partition = 1-n
-;             String      Path [String]     [String]        Int
-(defstruct db struct-name path (indexes ()) (partitions ()) (current-index 0)
-; {Int -> struct}
-  (data (make-hash-table))
+(defstruct db
+  struct-name              ; String
+  path                     ; Path
+  (indexes ())             ; [String]
+  (partitions ())          ; [String]
+  (current-index 0)        ; Int
+  (data (make-hash-table)) ; {Int -> struct}
   )
 
 (defun db/new (struct-name path)
   (ensure-directories-exist (concatenate 'string path "/data/"))
   (make-db :struct-name struct-name :path path))
 
-; example: db-path/indexes/by_name/
-(defun db/new-index (database attribute-name)
-  ; Create a directory for the indexes.
-  (ensure-directories-exist
-    (concatenate 'string (db-path database) "/indexes/by_" attribute-name "/"))
-  ; Add this new index to the list.
-  (push attribute-name (db-indexes database)))
+; Example: ./storage/cars 18 -> ./storage/cars/data/000000000000018.data
+; USAGE: when dealing with hash keys from the in-memory db.
+;        The hash key is the number used to build the filename.
+(defun db/data-filepath (dbpath number)
+  (concatenate 'string dbpath "/data/" (number->filename number)))
 
-; example: db-path/partitions/by_color/
-(defun db/new-partition (database attribute-name)
-  ; Create a directory for the partitions.
-  (ensure-directories-exist
-    (concatenate 'string (db-path database) "/partitions/by_" attribute-name "/"))
-  ; Add this new index to the list.
-  (push attribute-name (db-partitions database)))
-
-(defun to-upper-case (some-string)
-  (format nil "~@:(~a~)" some-string))
-
-(defun get-object-attribute (database attribute-name object)
-  (funcall ; example: call function "VEHICLE-COLOR"
-    (find-symbol (to-upper-case
-      (concatenate 'string (db-struct-name database) "-" attribute-name)))
-    object))
-
-; Example: returns "storage/cars/indexes/by_name/".
+; Example: returns "./storage/cars/indexes/by_name/".
 (defun db/index/get-directory-path (database name)
   (concatenate 'string (db-path database) "/indexes/by_" name "/" ))
 
-; Example: returns "storage/cars/partitions/by_color/".
+; Example: returns "./storage/cars/partitions/by_color/Red/".
 (defun db/partition/get-directory-path (database name value)
   (concatenate 'string (db-path database) "/partitions/by_" name "/" value "/"))
 
 ; Example: returns "Corvet".
 (defun db/index/get-filename (database index-name object)
-  (get-object-attribute database index-name object))
+  (get-object-attribute (db-struct-name database) index-name object))
 
+; Example: database "name" object -> "./storage/cars/indexes/by_name/Corvet".
 (defun db/index/get-symlink-path (database index-name object)
   (concatenate 'string
     (db/index/get-directory-path database index-name)
     (db/index/get-filename database index-name object)))
 
+; Example: database "name" object "0000000015.data"
+;   -> (ln "./storage/cars/indexes/by_name/Corvet"
+;          :target "../../data/0000000015.data"
+;          :hard nil)
 (defun db/index/new (database index-name object file-name)
-  (let ((symlink-path
-      (db/index/get-symlink-path database index-name object)))
+  (let ((symlink-path (db/index/get-symlink-path database index-name object)))
 
     ; Works even when the database directory is moved.
     (ln symlink-path
@@ -81,14 +83,20 @@
       :hard nil)
   ))
 
+; Example: database "color" object
+;   -> "./storage/cars/partitions/by_color/Red/0000000015.data".
 (defun db/partition/get-symlink-path (database partition-name object file-name)
   (concatenate 'string
     (db/partition/get-directory-path database partition-name
       ; example: "Red"
-      (get-object-attribute database partition-name object))
-    ; example: "000000000000018.data"
+      (get-object-attribute (db-struct-name database) partition-name object))
+    ; example: "0000000015.data"
     file-name))
 
+; Example: database "color" object "0000000015.data"
+;   -> (ln "./storage/cars/partitions/by_color/Red/0000000015.data"
+;          :target "../../../data/0000000015.data"
+;          :hard nil)
 (defun db/partition/new (database partition-name object file-name)
   (let ((symlink-path
       (db/partition/get-symlink-path database partition-name object file-name)))
@@ -100,9 +108,37 @@
       :target (concatenate 'string "../../../data/" file-name)
       :hard nil)))
 
-; Example: 000000000000018.data
+; example: db-path/indexes/by_name/
+(defun db/new-index (database attribute-name)
+  ; Create a directory for the indexes.
+  (ensure-directories-exist
+    (concatenate 'string (db-path database) "/indexes/by_" attribute-name "/"))
+
+  ; Add this new index to the list.
+  (push attribute-name (db-indexes database))
+
+  ; Generate index for all DB elements.
+  (maphash #'(lambda (number element)
+      (db/index/new database attribute-name element (number->filename number)))
+    (db-data database)))
+
+; example: db-path/partitions/by_color/
+(defun db/new-partition (database attribute-name)
+  ; Create a directory for the partitions.
+  (ensure-directories-exist
+    (concatenate 'string (db-path database) "/partitions/by_" attribute-name "/"))
+
+  ; Add this new index to the list.
+  (push attribute-name (db-partitions database))
+
+  ; Generate partition for all DB elements.
+  (maphash #'(lambda (number element)
+      (db/partition/new database attribute-name element (number->filename number)))
+    (db-data database)))
+
+; Example: database -> "000000000000018.data".
 (defun db/add/new-data-filename (database)
-  (format nil "~15,'0D.data" (db-current-index database)))
+  (number->filename (db-current-index database)))
 
 ; Example: {db-path}/data/000000000000018.data
 (defun db/add/new-data-filepath (database file-name)
@@ -111,6 +147,8 @@
 (defun db/add (database object)
   (incf (db-current-index database))
   (let ((file-name (db/add/new-data-filename database)))
+
+    ; write object to file
     (util:write-object-to-file
       object
       (db/add/new-data-filepath database file-name))
@@ -124,6 +162,7 @@
        do (db/partition/new database partition object file-name)))
 
   ; store new in-memory data
+  ; database.data[database.current-index] = object
   (setf (gethash (db-current-index database) (db-data database)) object))
 
 ; TODO: should we search for the data from the FS or in-memory?
@@ -143,12 +182,12 @@
 
 (defparameter cars (db/new "vehicle" "./storage/cars/"))
 
+(db/add cars (make-vehicle :name "Corvet"   :color "Red"))
+(db/add cars (make-vehicle :name "Deudeuch" :color "Beige"))
+
 (db/new-index cars "name")
 (db/new-partition cars "color")
 
-(db/add cars (make-vehicle :name "Corvet" :color "Red"))
-(db/add cars (make-vehicle :name "Deudeuch" :color "Beige"))
-
 (format t "~&~S~&" cars)
 
 (format t "db/get-by-index ~S~&" (db/get-by-index cars "name" "Corvet"))