Read-only base AtomSpace, with a read-write overlay.

[linas]

This is a basic implementation of a solution for issue #1855. This allows user to create a base atomspace that acts as a cache of atoms from a database, and mark it read-only. An overlay atomspace can be use with this, and atoms can be modified in the overlay. If an attempt is made to set a truth value (or a generic value) on an atom in the read-only base space, it is automatically copied into the overlay space, where the value can be changed. The atom in the base space is left untouched.

Basic example in examples/atomspace/copy-on-write.scm. It works. Includes unit tests.

Note also: even though an atomspace is marked "read-only", one can still fetch from the database, and also extract atoms from the atomspace, thus allowing RAM usage to be managed, without altering the read-only nature of the data in the database.

[bgoertzel]

Wow, nice!

…

On Mon, Nov 5, 2018 at 7:40 AM Linas Vepštas ***@***.***> wrote: This is a basic implementation of a solution for issue #1855 <#1855>. This allows user to create a base atomspace that acts as a cache of atoms from a database, and mark it read-only. An overlay atomspace can be use with this, and atoms can be modified in the overlay. If an attempt is made to set a truth value (or a generic value) on an atom in the read-only base space, it is automatically copied into the overlay space, where the value can be changed. The atom in the base space is left untouched. Basic example in examples/atomspace/copy-on-write.scm. It works. Includes unit tests. Note also: even though an atomspace is marked "read-only", one can still fetch from the database, and also extract atoms from the atomspace, thus allowing RAM usage to be managed, without altering the read-only nature of the data in the database. ------------------------------ You can view, comment on, or merge this pull request online at: #1895 Commit Summary - Start work on a very simple permissions system. - Start implementing the read-only constraint. - One more read-only enforcement. - Add temporary scheme bindings for the readonly flag. - Readonly flag -- missed a few spots - Add wrappers for value setters. - Force copying of atoms from read-only atomspaces. - Bug-fix the force-addition of duplicate atoms - Wrap excessively long lines - Avoid pointless copy. - Remove some pointless computation. - Hmm. Make note of some weirdness... - Optimize traversal - Simlify and optimze slow sloppy code. - De-duplicate atoms. - More atom table deduplication - Migrate to the new disambiguated code - Remove dead code. - Additional documentation - Fixup COW printing - And catch the exceptions, too. - Start work on new COW unit test - Expand the COW unit test - Expand the fetch utest for readonly work. - Test reloading after extraction. - Bug-fix atom rel-loading after extraction - Ad a COW demo File Changes - *M* examples/atomspace/README.md <https://github.com/opencog/atomspace/pull/1895/files#diff-0> (15) - *A* examples/atomspace/copy-on-write.scm <https://github.com/opencog/atomspace/pull/1895/files#diff-1> (53) - *M* opencog/atomspace/AtomSpace.cc <https://github.com/opencog/atomspace/pull/1895/files#diff-2> (108) - *M* opencog/atomspace/AtomSpace.h <https://github.com/opencog/atomspace/pull/1895/files#diff-3> (106) - *M* opencog/atomspace/AtomTable.cc <https://github.com/opencog/atomspace/pull/1895/files#diff-4> (45) - *M* opencog/atomspace/AtomTable.h <https://github.com/opencog/atomspace/pull/1895/files#diff-5> (83) - *M* opencog/guile/SchemeSmob.cc <https://github.com/opencog/atomspace/pull/1895/files#diff-6> (3) - *M* opencog/guile/SchemeSmob.h <https://github.com/opencog/atomspace/pull/1895/files#diff-7> (3) - *M* opencog/guile/SchemeSmobAS.cc <https://github.com/opencog/atomspace/pull/1895/files#diff-8> (45) - *M* opencog/guile/SchemeSmobAtom.cc <https://github.com/opencog/atomspace/pull/1895/files#diff-9> (27) - *M* opencog/guile/SchemeSmobNew.cc <https://github.com/opencog/atomspace/pull/1895/files#diff-10> (28) - *M* opencog/guile/SchemeSmobValue.cc <https://github.com/opencog/atomspace/pull/1895/files#diff-11> (13) - *M* opencog/persist/sql/multi-driver/SQLResponse.h <https://github.com/opencog/atomspace/pull/1895/files#diff-12> (6) - *M* opencog/scm/opencog/base/utilities.scm <https://github.com/opencog/atomspace/pull/1895/files#diff-13> (24) - *M* tests/atomspace/CMakeLists.txt <https://github.com/opencog/atomspace/pull/1895/files#diff-14> (1) - *A* tests/atomspace/COWSpaceUTest.cxxtest <https://github.com/opencog/atomspace/pull/1895/files#diff-15> (101) - *M* tests/persist/sql/multi-driver/FetchUTest.cxxtest <https://github.com/opencog/atomspace/pull/1895/files#diff-16> (64) Patch Links: - https://github.com/opencog/atomspace/pull/1895.patch - https://github.com/opencog/atomspace/pull/1895.diff — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#1895>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AFolXJYoD2pfAa5Oz4WmZI9WjrXZK33hks5ur-swgaJpZM4YN6je> .

-- Ben Goertzel, PhD http://goertzel.org "The dewdrop world / Is the dewdrop world / And yet, and yet …" -- Kobayashi Issa