Rucksack code

Persistent objects

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Variable *RUCKSACK* The current rucksack (NIL if there is no open rucksack).

Function CURRENT-RUCKSACK

Persistent objects API

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Generic Function OBJECT-ID Returns the object id of a persistent-object or persistent-data.

Generic Function P-EQL The persistent equivalent of EQL.

Method (P-EQL T T)

Proxy

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Class PROXY Proxies are some kind of in-memory forwarding pointer to data in the cache.

Variable *DONT-DEREFERENCE-PROXIES*

Method (MAYBE-DEREFERENCE-PROXY PROXY)

Method (MAYBE-DEREFERENCE-PROXY T)

Function CACHE

Low level persistent data structures

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Class PERSISTENT-DATA PERSISTENT-DATA classes do not have PERSISTENT-CLASS as metaclass because we don't want to specialize SLOT-VALUE-USING-CLASS & friends for persistent-data instances.

Method (PRINT-OBJECT PERSISTENT-DATA T)

Method (COMPUTE-PERSISTENT-SLOT-NAMES STANDARD-CLASS PERSISTENT-DATA)

Method (P-EQL PERSISTENT-DATA PERSISTENT-DATA)

Method (PERSISTENT-DATA-READ T PERSISTENT-DATA)

Method (PERSISTENT-DATA-WRITE T PERSISTENT-DATA T)

Function MAKE-PERSISTENT-DATA

Persistent array

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Class PERSISTENT-ARRAY

Function P-MAKE-ARRAY

Method (P-AREF PERSISTENT-ARRAY)

Method ((SETF P-AREF) T PERSISTENT-ARRAY)

Method (P-ARRAY-DIMENSIONS PERSISTENT-ARRAY)

Persistent CONS

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Class PERSISTENT-CONS

Function P-CONS

Method (P-CAR PERSISTENT-CONS)

Method (P-CAR (EQL NIL))

Method ((SETF P-CAR) T PERSISTENT-CONS)

Method (P-CDR PERSISTENT-CONS)

Method (P-CDR (EQL NIL))

Method ((SETF P-CDR) T PERSISTENT-CONS)

Function P-LIST

Function UNWRAP-PERSISTENT-LIST Converts a persistent list to a 'normal' Lisp list.

Function P-CAAR The persistent equivalent of CAAR.

Function P-CADR The persistent equivalenet of CADR.

Function P-CDAR The persistent equivalent of CDAR.

Function P-CDDR The persistent equivalent of CDDR.

Method (P-CONSP PERSISTENT-CONS)

Method (P-CONSP T)

Method (P-ENDP (EQL NIL))

Method (P-ENDP PERSISTENT-CONS)

Method (P-ENDP T)

Function P-LAST Returns the last persistent cons cell of a persistent list (or NIL if the list is empty).

Macro P-POP Pop an item from the persistent list specified by PLACE.

Macro P-PUSH Push ITEM onto the persistent list specified by PLACE.

Persistent sequence

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Function CHECK-P-VECTOR

Method (P-LENGTH PERSISTENT-ARRAY)

Method (P-LENGTH PERSISTENT-CONS)

Method (P-FIND T PERSISTENT-ARRAY)

Method (P-FIND T PERSISTENT-CONS)

Method (P-FIND T (EQL NIL))

Method (P-POSITION T PERSISTENT-ARRAY)

Method (P-POSITION T PERSISTENT-CONS)

Method (P-REPLACE PERSISTENT-ARRAY PERSISTENT-ARRAY)

Method (P-DELETE-IF T PERSISTENT-CONS)

Method (P-NREVERSE (EQL NIL))

Method (P-NREVERSE PERSISTENT-CONS)

Full fledged persistent objects

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Class PERSISTENT-OBJECT Classes of metaclass PERSISTENT-CLASS automatically inherit from this class.

Variable *INITIALIZING-INSTANCE*

Method (INITIALIZE-INSTANCE AROUND PERSISTENT-OBJECT)

Method (PRINT-OBJECT PERSISTENT-OBJECT T)

Method (P-EQL PERSISTENT-OBJECT PERSISTENT-OBJECT)

Method (P-EQL PERSISTENT-DATA PERSISTENT-OBJECT)

Method (P-EQL PERSISTENT-OBJECT PERSISTENT-DATA)

Method (SLOT-VALUE-USING-CLASS AROUND PERSISTENT-CLASS T T)

Method ((SETF SLOT-VALUE-USING-CLASS) AROUND T PERSISTENT-CLASS T T)

Method (SLOT-MAKUNBOUND-USING-CLASS AROUND PERSISTENT-CLASS T T)

Function SLOT-DEF-AND-NAME Returns (1) slot definition and (2) slot name.

Serializing/deserializing cached data

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Constant +P-OBJECT+ The serialization marker for cached objects.

Method (SERIALIZE PERSISTENT-OBJECT T)

Method (SERIALIZE PERSISTENT-DATA T)

Method (SERIALIZE PROXY T)

Method (DESERIALIZE-CONTENTS (EQL +P-OBJECT+) T)

Method (SCAN-CONTENTS (EQL +P-OBJECT+) SERIALIZATION-BUFFER MARK-AND-SWEEP-HEAP)

Method (SCAN-OBJECT T SERIALIZATION-BUFFER T)

Loading/updating cached objects

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Method (SAVE-OBJECT T T STANDARD-CACHE T T) Serializes the object to a buffer, allocates a heap block of the right size and writes the buffer to the block.

Function SERIALIZE-PREVIOUS-VERSION-POINTER

Method (LOAD-OBJECT T T STANDARD-CACHE)

Function FIND-COMMITTED-OBJECT-VERSION Returns the buffer, id, nr-slots and schema-id of the object containing the compatible version for the given transaction id.

Function LOAD-OBJECT-FIELDS Returns id, nr-slots, schema-id, transaction-id and prev-version (as 5 values).

When a persistent object must be loaded from disk, Rucksack loads the schema nr and finds the corresponding schema. If the schema is obsolete (i.e. there is a schema for the same class with a higher version number), Rucksack calls the generic function UPDATE-PERSISTENT-INSTANCE-FOR-REDEFINED-CLASS after calling ALLOCATE-INSTANCE for the current class version. The generic function is very similar to UPDATE-INSTANCE-FOR-REDEFINED-CLASS: it takes a list of added slots, a list of deleted slots and a property list containing the slot names and values for slots that were discarded and had values.

Generic Function UPDATE-PERSISTENT-INSTANCE-FOR-REDEFINED-CLASS

Method (UPDATE-INSTANCE-FOR-REDEFINED-CLASS PERSISTENT-OBJECT T T T)