March 1998
- Describe Concept Stephen Zepp
- Describe Concept Jon A. Lambert
- Describe Concept J C Lawrence
- Describe Concept Jon A. Lambert
- Describe Concept J C Lawrence
- Describe Concept Vadim Tkachenko
- Tutorial: Let's build a Compiler! - Part XI: Lexical Scan Revisited Jon A. Lambert
- Tutorial: Let's build a Compiler! - Part XII: Miscellany Jon A. Lambert
- Tutorial: Let's build a Compiler! - Part XIII: Procedures Jon A. Lambert
- Tutorial: Let's build a Compiler! Chris Gray
- VEIL Network Protocol Brandon Gillespie
- Tutorial: Let's build a Compiler! - Part XIV: Types Jon A. Lambert
- Tutorial: Let's build a Compiler! - Part XV: Back to the Future Jon A. Lambert
- Tutorial: Let's build a Compiler! - Part XVI: Unit Construction Jon A. Lambert
- For Ling's FAQ Koster, Raph
- MUD Ratings jlsysinc.ix.netcom.com@ix.netcom.com
- Random Generation Tools Ling
- ANNOUNCE: DB Robin Carey
- THE DARKWHOLE TESTS J C Lawrence
- Magic as Metaphor J C Lawrence
- Magic as Metaphor J C Lawrence
- Magic as Metaphor Jon A. Lambert
- Magic as Metaphor J C Lawrence
- CT - A Hypothetical Session (mid 1995) J C Lawrence
- 2Cyberconf: An article J C Lawrence
- (long) AnarchyMOO Primary Log J C Lawrence
- (short) AnarchyMOO parting salute J C Lawrence
- AnarchyMOO purpose J C Lawrence
- (fwd) CODE RELEASE: [client] Spod! (Java mud client) J C Lawrence
- (fwd) CODE RELEASE: [client]: lyntin (hacker's client) 1.1b Released J C Lawrence
- DarkWhole Test #1 J C Lawrence
- DarkWhole Test #2 J C Lawrence
- DarkWhole test #3 J C Lawrence
- DarkWhole test #4 J C Lawrence
- DarkWhole test #5 J C Lawrence
- DarkWhole test Identity Crisis J C Lawrence
- The Craft of Adventure J C Lawrence
- What in THE Hell was that? Stephen Zepp
- What in THE Hell was that? Ben Greear
- What in THE Hell was that? J C Lawrence
- What in THE Hell was that? Jon A. Lambert
- (fwd) Varying Time Commitment Levels: what's an admin to do? J C Lawrence
- Hello, and a brief intro cimri
- Hello, and a brief intro Ben Greear
- (no title) Time limits? s001gmu@nova.wright.edu
- (no title) Time limits? Justin McKinnerney
- (no title) Time limits? J C Lawrence
- Speaking of Avatars Jon A. Lambert
- Speaking of Avatars Jon A. Lambert
- Speaking of Avatars J C Lawrence
- Speaking of Avatars Jon A. Lambert
- Re: Vadim Tkachenko
- META: Broken mail headers coder@ibm.net
- META: Broken mail headers Alex Oren
- META: Broken mail headers J C Lawrence
- META: Broken mail headers Alex Oren
- META: Broken mail headers J C Lawrence
- META: Broken mail headers Chris Gray
- META: Broken mail headers J C Lawrence
- META: Broken mail headers Caliban Tiresias Darklock
- META: Broken mail headers Chris Gray
- Turn-based MU*'s Sauron
- Balancing Addicts -> soft vs. hard enforcement cimri
- Balancing Addicts -> soft vs. hard enforcement Justin McKinnerney
- Balancing Addicts -> soft vs. hard enforcement J C Lawrence
- Balancing Addicts -> soft vs. hard enforcement Jon A. Lambert
- Balancing Addicts -> soft vs. hard enforcement Ling
- Balancing Addicts -> soft vs. hard enforcement Jon A. Lambert
- Balancing Addicts -> soft vs. hard enforcement Matt Chatterley
- Balancing Addicts -> soft vs. hard enforcement J C Lawrence
- Balancing Addicts -> soft vs. hard enforcement Jon A. Lambert
- Balancing Addicts -> soft vs. hard enforcement Matt Chatterley
- Balancing Addicts -> soft vs. hard enforcement Adam Wiggins
- Balancing Addicts -> soft vs. hard enforcement Joel Dillon
- SfD: Clientside Caching Nathan F Yospe
- SfD: Clientside Caching Jon A. Lambert
- SfD: Clientside Caching Nathan F Yospe
- SfD: Clientside Caching Chris Gray
- SfD: Clientside Caching Jon A. Lambert
- (subject missing) J C Lawrence
- Balancing Addicts Ling
- Balancing Addicts Richard Woolcock
- Balancing Addicts Ling
- Balancing Addicts J C Lawrence
- Transport layer (UDP vs TCP) Ben Greear
- Transport layer (UDP vs TCP) Niklas Elmqvist
- Transport layer (UDP vs TCP) Jon Leonard
- Transport layer (UDP vs TCP) Ben Greear
- Transport layer (UDP vs TCP) Jon Leonard
- Transport layer (UDP vs TCP) Ben Greear
- Transport layer (UDP vs TCP) Chris Gray
- Transport layer (UDP vs TCP) Niklas Elmqvist
- Transport layer (UDP vs TCP) Jon A. Lambert
- Transport layer (UDP vs TCP) Ben Greear
- Time Limits? Jon A. Lambert
- META: topic and thread culling (was Balancing Addicts -> soft vs. hard enforcement ) J C Lawrence
- (subject missing) J C Lawrence
- XShipWars J C Lawrence
- (fwd) INFO: [client] Chaco looking for new parent for Pueblo J C Lawrence
- SIMULATING FUTURE HISTORIES: THE NAU SOLAR SYSTEM SIMULATION & MARS SETTLEMENT J C Lawrence
- (fwd) Functional Security J C Lawrence
- (fwd) Functional Security Ling
- (fwd) Functional Security Chris Gray
- (fwd) Functional Security Matt Chatterley
- (fwd) Functional Security Miroslav Silovic
- (fwd) Functional Security Felix A. Croes
- (fwd) Functional Security J C Lawrence
- SIMULATING FUTURE HISTORIES s001gmu@nova.wright.edu
- Character development [was ] Matt Chatterley
- Character development [was ] J C Lawrence
- Character development [was ] Matt Chatterley
- Character development [was ] Travis Casey
- Character development [was ] J C Lawrence
- Character development [was ] Travis S. Casey
- Character development [was ] Marian Griffith
- Character development [was ] Travis S. Casey
- Character development [was ] Vadim Tkachenko
- Character development [was ] Travis Casey
- Character development [was ] Vadim Tkachenko
- Character development [was ] Travis Casey
- Character development [was ] Vadim Tkachenko
- Character development [was ] Marian Griffith
- Character development [was ] Vadim Tkachenko
- Character development [was ] Marian Griffith
- Character development [was ] s001gmu@nova.wright.edu
- Character development [was ] Marian Griffith
- Character development [was ] J C Lawrence
- Character development [was ] Cimri
- Character development [was ] J C Lawrence
- Character development [was ] s001gmu@nova.wright.edu
- Character development [was ] Caliban Tiresias Darklock
- Character development [was ] Caliban Tiresias Darklock
- Character development [was ] Vadim Tkachenko
- Character development [was ] Ben Greear
- Character development [was ] Matt Chatterley
- Character development [was ] J C Lawrence
- Character development [was ] Matt Chatterley
- Character development [was ] Travis S. Casey
- Character development [was ] J C Lawrence
- Character development [was ] Koster, Raph
- Character development [was ] J C Lawrence
- Character development [was ] Koster, Raph
- Character development [was ] Alex Bertoglio
- Character development [was ] J C Lawrence
- Character development [was ] J C Lawrence
- Character development [was ] John Bertoglio
- 3D engines for MUDs Niklas Elmqvist
- 3D engines for MUDs Chris Gray
- 3D engines for MUDs J C Lawrence
- 3D engines for MUDs Niklas Elmqvist
- 3D engines for MUDs Chris Gray
- 3D engines for MUDs Ling
- 3D engines for MUDs Koster, Raph
- 3D engines for MUDs Mike Sellers
- 3D engines for MUDs Niklas Elmqvist
- 3D engines for MUDs Koster, Raph
- 3D engines for MUDs Ling
- 3D engines for MUDs s001gmu@nova.wright.edu
- Dynamic Loading of Modules Niklas Elmqvist
- Dynamic Loading of Modules Greg Munt
- Dynamic Loading of Modules J C Lawrence
- Parlez vous NPC? Matt Chatterley
- Parlez vous NPC? Vadim Tkachenko
- Parlez vous NPC? Matt Chatterley
- Parlez vous NPC? Chris Gray
- Parlez vous NPC? Matt Chatterley
- Parlez vous NPC? Nathan F Yospe
- Parlez vous NPC? Matt Chatterley
- Dynamic Loading of Modules Niklas Elmqvist
- Dynamic Loading of Modules Chris Gray
- Dynamic Loading of Modules Jon A. Lambert
- World Persistence, flat files v/s DB v/s ?? Ben Greear
- World Persistence, flat files v/s DB v/s ?? Chris Gray
- World Persistence, flat files v/s DB v/s ?? Jon A. Lambert
- World Persistence, flat files v/s DB v/s ?? Greg Munt
- World Persistence, flat files v/s DB v/s ?? Chris Gray
- World Persistence, flat files v/s DB v/s ?? Matt Chatterley
- World Persistence, flat files v/s DB v/s ?? s001gmu@nova.wright.edu
- World Persistence, flat files v/s DB v/s ?? Vadim Tkachenko
- World Persistence, flat files v/s DB v/s ?? Vadim Tkachenko
- World Persistence, flat files v/s DB v/s ?? Matt Chatterley
- World Persistence, flat files v/s DB v/s ?? Ben Greear
- World Persistence, flat files v/s DB v/s ?? Vadim Tkachenko
- World Persistence, flat files v/s DB v/s ?? Joel Dillon
- World Persistence, flat files v/s DB v/s ?? Joel Dillon
- World Persistence, flat files v/s DB v/s ?? Vadim Tkachenko
- World Persistence, flat files v/s DB v/s ?? Matt Chatterley
- World Persistence, flat files v/s DB v/s ?? Chris Gray
- World Persistence, flat files v/s DB v/s ?? Ross Nicoll
- World Persistence, flat files v/s DB v/s ?? Ross Nicoll
- World Persistence, flat files v/s DB v/s ?? Matt Chatterley
- World Persistence, flat files v/s DB v/s ?? Vadim Tkachenko
- World Persistence, flat files v/s DB v/s ?? s001gmu@nova.wright.edu
- World Persistence, flat files v/s DB v/s ?? Joel Dillon
- World Persistence, flat files v/s DB v/s ?? Matt Chatterley
- World Persistence, flat files v/s DB v/s ?? Vadim Tkachenko
- World Persistence, flat files v/s DB v/s ?? J C Lawrence
- World Persistence, flat files v/s DB v/s ?? Chris Gray
- World Persistence, flat files v/s DB v/s ?? J C Lawrence
- World Persistence, flat files v/s DB v/s ?? Vadim Tkachenko
- World Persistence, flat files v/s DB v/s ?? Chris Gray
- World Persistence, flat files v/s DB v/s ?? J C Lawrence
- World Persistence, flat files v/s DB v/s ?? Jon A. Lambert
- World Persistence, flat files v/s DB v/s ?? J C Lawrence
- World Persistence, flat files v/s DB v/s ?? Ben Greear
- World Persistence, flat files v/s DB v/s ?? Matt Chatterley
- World Persistence, flat files v/s DB v/s ?? Ben Greear
- World Persistence, flat files v/s DB v/s ?? Jon A. Lambert
- World Persistence, flat files v/s DB v/s ?? J C Lawrence
- World Persistence, flat files v/s DB v/s ?? Joel Dillon
- World Persistence, flat files v/s DB v/s ?? Matt Chatterley
- World Persistence, flat files v/s DB v/s ?? Joel Dillon
- World Persistence, flat files v/s DB v/s ?? J C Lawrence
- World Persistence, flat files v/s DB v/s ?? Joel Dillon
- World Persistence, flat files v/s DB v/s ?? J C Lawrence
- World Persistence, flat files v/s DB v/s ?? Matt Chatterley
- World Persistence, flat files v/s DB v/s ?? J C Lawrence
- World Persistence, flat files v/s DB v/s ?? Adam Wiggins
- World Persistence, flat files v/s DB v/s ?? Ben Greear
- World Persistence, flat files v/s DB v/s ?? Orion Henry
- World Persistence, flat files v/s DB v/s ?? Ben Greear
- World Persistence, flat files v/s DB v/s ?? Nathan F Yospe
- World Persistence, flat files v/s DB v/s ?? Ben Greear
- World Persistence, flat files v/s DB v/s ?? Vadim Tkachenko
- World Persistence, flat files v/s DB v/s ?? J C Lawrence
- World Persistence, flat files v/s DB v/s ?? J C Lawrence
- World Persistence, flat files v/s DB v/s ?? Greg Munt
- World Persistence, flat files v/s DB v/s ?? Ben Greear
- World Persistence, flat files v/s DB v/s ?? Jon A. Lambert
- World Persistence, flat files v/s DB v/s ?? J C Lawrence
- World Persistence, flat files v/s DB v/s ?? J C Lawrence
- World Persistence, flat files v/s DB v/s ?? Chris Gray
- World Persistence, flat files v/s DB v/s ?? J C Lawrence
- Jukebox Vadim Tkachenko
- Another recruit for the list? Joel Dillon
- OT: Martin Keegan J C Lawrence
- Old code Joel Dillon
- Old code Michael Hohensee
- UML/Commercial v Free Muds Greg Munt
- UML/Commercial v Free Muds Nathan F Yospe
- UML/Commercial v Free Muds Jon A. Lambert
- Heightfield Terrain Rendering Paper Niklas Elmqvist
- (subject missing) J C Lawrence
- (fwd) Roleplaying J C Lawrence
- (fwd) Roleplaying s001gmu@nova.wright.edu
- (fwd) Roleplaying Katrina McClelan
- (fwd) Roleplaying Ling
- (fwd) Roleplaying J C Lawrence
- (fwd) Roleplaying Travis Casey
- Predicting future motion intelligently J C Lawrence
- META: New Mail server and ISP J C Lawrence
- (rec.games.mud.admin) Roleplaying (fwd) Nathan F Yospe
- Persistant storage.... My current idea. Ben Greear
- Persistant storage.... My current idea. Jon A. Lambert
- Persistant storage.... My current idea. Ben Greear
- Persistant storage.... My current idea. J C Lawrence
On Sat, 28 Mar 1998 21:53:09 PST8PDT
Ben Greear<greear@cyberhighway.net> wrote:
> I'm currently planning on using one file, with certain blocks
> allocated within it for objects. It will basically be a linked list
> represented as a file.
> I'll have headers that point the the seek position of the next and
> previous element in the file. It will also keep track of the used
> and total space allocated for that element.
> If I need to update, and it's too big, it will be moved to the end
> of the file, and the previous element will get it's space. (I'll
> deal with boundary cases, sufice it to say.)
> Now, this reeks of inneficiency when trying to look up an object
> based on some key (object number in my case, probably 8 bytes ).
> However, I'm going to create a hash table at boot time to link an
> object id with the seek position of that object in the file. I
> believe this should give me as quick access as I can expect.
A very simple cheat which performs very nicely is to do something as
follows:
Every record in the DB is identified by a unique record # of a
signed integer type.
The DB consists of two files, the database itself, and an index.
The index file is an array of the following structures:
struct {
off_t record_pos; // Offset of the record in the DB
size_t record_len; // Length of the record in the DB
}
The N'th structure in the index file, located by seeking to an
offset of (N *sizeof (struct)) and then reading sizeof (struct) bytes,
holds the data for the record in the DB with a record number of N.
Seeking to offset record_pos in the DB file and reading record_len
bytes will get you the wrapped contents of that record.
The DB file is an amorphous binary blob of no particular pattern.
It contains records of variable length which follow a particular
pattern:
struct {
unsigned char beg_signature[16];
signed long record_num;
size_t record_len;
unsigned char data[1]; // the actual contents of the record,
// record_len bytes long.
off_t next_record; // Offset of next record in DB
unsigned char end_signature[16];
}
This pattern is the "wrapped" pattern. The first record_len bytes
of the data[] array are the actual data contents of the record.
There is reason behind the signatures and the like. Look at tdbm
and YOODA for working models. The base reason here is so that the
index file can be reconstructed from the DB file, and so that gross
format corruption can be detected.
New records are added into either the first free space in the DB
file that is large enough to hold them, or some "best fit" equivalent.
As old records are deleted this opens "spaces" that new records (with
potentially very different record numbers) will be inserted into.
Order has no importance in the DB file -- that is what the index file
is for.
Of course eventually your DB will be peppered with such small spaces
which are too small for new records -- then you pack the DB.
> Some other things: I'll have objects unique across the universe,
> even different servers. (Each server will be assigned an ID, and
> each object within that server will have a unique ID. So, given
> both ID's, I can guarantee uniqueness.)
You need to look at Cool -- it did exactly this with some success.
> PS. I hope the fact that the last message I saw was about a change
> in the mailing list software isn't a bad sign!!
I now have a dedicated 'net connection at home. In celebration I'm
moving the list to Petidomo (see www.petidomo.com), and adding
searchable web archives of past list traffic (yes, email addresses
will be munged), and a backing FTP site. This transfer was supposed
to be happening today. It didn't and it won't, not today. Sorry.
RSN.
--
J C Lawrence Internet: claw@null.net
(Contractor) Internet: coder@ibm.net
---------(*) Internet: claw@under.engr.sgi.com
...Honourary Member of Clan McFud -- Teamer's Avenging Monolith... - Persistant storage.... My current idea. Ben Greear
- Persistant storage.... My current idea. J C Lawrence
- Persistant storage.... My current idea. Ben Greear
- Persistant storage.... My current idea. Chris Gray
- Persistant storage.... My current idea. Ben Greear
- Persistant storage.... My current idea. J C Lawrence
- Persistant storage.... My current idea. Ben Greear
- UML & CORBA Greg Munt
- [MUD-Dev]: smoothing J C Lawrence
- [MUD-Dev]: smoothing J C Lawrence