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<center><h1><font size="+3"><p>Scalable Distributed Data Structure Extension To Monet</font></h1><h2><p><font size="+2">0.4<p></font></h2></center>
<center><h3><font size="+1"><p>Jonas S Karlsson<p></font></h3></center><center><h3><font size="+1"><p>1997-07-18<p></font></h3></center>
<hr size=5 noshade>
<h2>Table Of Contents</h2>
<h3><a href="#mod_1_0_0">SDDS implications of Monet</a></h3>
<ul><li>
[<a href="#mod_1_1_0">Todo:</a>]
[<a href="#mod_1_2_0">Discussion about ATOMic values in MONET</a>]
[<a href="#mod_1_3_0">Structure</a>]
[<a href="#mod_1_4_0">Atom Declarations </a>]
</ul>
<h3><a href="#mod_2_0_0">The SDDS FILE class</a></h3>
<ul><li>
[<a href="#mod_2_1_0">Handy macros</a>]
[<a href="#mod_2_2_0">Command Declarations</a>]
[<a href="#mod_2_3_0">Server side functions</a>]
</ul>
<h3><a href="#mod_3_0_0">Methods for lhslh </a></h3>
<ul><li>
[<a href="#mod_3_1_0">General Includes</a>]
[<a href="#mod_3_2_0">Actual Command Implementation</a>]
</ul>
<hr size=5 noshade><hr size=5 noshade><br><br><a name=mod_1_0_0>
<h2>1 SDDS implications of Monet</h2>
This module implements basic functionality concerning Scalable
Distributed Data Structures (SDDSs), LH*(LH) in particular. It
provides:<br> <ul>
<li> The <i> Client Data</i> for managing the image of the client.
<li> The <i> Client Algorithms</i> used for calculating the most
likely server node that stores one piece of data.
<li> The <i> Server List</i> that is the mapping from logical server
number to a physical machine identity.
</ul><br><hr size=5 noshade><br><a name=mod_1_1_0>
<h4>1.1 Todo:</h4>
<ul>
<li> An implementation of the client data functions.
<li> The client algorithms for address calculations.
<li> The server algorithms for address calculations.
<li> How to handle local server data. (general interface). What types?
<li> A simulated SDDS with client/server on the same node.
</ul><br><hr size=5 noshade><br><a name=mod_1_2_0>
<h4>1.2 Discussion about ATOMic values in MONET</h4>Interesting enough is that during MIL execution the atomic values
are (often) copied. It is undefined from the semantics when values
are copied or not. This means that an atom should not be modified
in place since there is no guarantees that the /actual/ instance
of ATOM is the one you have a reference to. <br>This gives a few possibilities for implementation of a "record"
of information:<br> <ul>
<li> Decluster the attributes of the object/record (typical monet style).
This approach is tedious since there will be many tables -- one
for each attribute. This is good if one wants to make queries
over the SDDS meta-information. I cannot really forsee that.<br><li> Store the "state" as an ATOM. Replace atom then there is a new
state. Updates will be faster (better concurrency) than in the
decluster approach. A potential problem is that since the
state is copied, updates might take longer to propagate.
(since copies are passed around during processing)
</ul><br>I've decied to go for the second approach. It might not be
the best. But it is not used in too much in MONET. So
why not... '<br>Locking should be used when looking up the ATOM from
the BAT and also when updating it. But that is an
"application problem" (according to MK). Maybe
it means that MIL code (advanced operations, should
do this themselves). Since the actual update or
atom lookup can be implemented by two interface functions
I (jonas) think they should do the locking. Locks for
this data is expected to be cheap, especially since this
gives (eventually, maybe it should be required?) a copy
of the ATOM.<br>The other (more MONETY) alternative is to create
atoms, and not update them. The update returns
a new up-to-date atom that the client inserts.<br><hr size=5 noshade><br><a name=mod_1_3_0>
<h4>1.3 Structure</h4>
There are two new MONET ATOMic values; LHSLH is the
client information; LHSLH_SERVER is the server side
information. The latter "points"(should lookup from table)
to a LHSLH_CLIENT.
At each site (both client and servers) there is some
global tables -- sdds_clients that stores client atoms,
and sdds_servers that stores server atoms.
And there is a mapping from global logical machine number
(sdds_machines) to a physcial instance (at the moment
"tcpipname:port").
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.m</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 92 </font>
<font color="8FBC8F" size="-2"> 93 </font>MODULE sdds;
<font color="8FBC8F" size="-2"> 94 </font>USE tcpip;
</font></pre>
<hr size=5 noshade><br><a name=mod_1_4_0>
<h4>1.4 Atom Declarations </h4><br><a name=mod_1_4_1>
<h5><b>1.4.1 LH*lh Client Image</b></h5>
The client images data, such as $i$ and $p$, which hashfunction
and what Server List (mapping) that is used. For each file
there is one (at least) client image at the server site.
<hr size=5 noshade><hr size=5 noshade><br><br><a name=mod_2_0_0>
<h2>2 The SDDS FILE class</h2>
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.h</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 104 </font>
<font color="8FBC8F" size="-2"> 105 </font>#ifndef __LHSLH_H__
<font color="8FBC8F" size="-2"> 106 </font>#define __LHSLH_H__
<font color="8FBC8F" size="-2"> 107 </font>
<font color="8FBC8F" size="-2"> 108 </font> #define _DEBUG_
<font color="8FBC8F" size="-2"> 109 </font>
<font color="8FBC8F" size="-2"> 110 </font>typedef struct lhslh {
<font color="8FBC8F" size="-2"> 111 </font> unsigned long id;
<font color="8FBC8F" size="-2"> 112 </font> unsigned int level;
<font color="8FBC8F" size="-2"> 113 </font> unsigned int split;
<font color="8FBC8F" size="-2"> 114 </font> bat mappingid;
<font color="8FBC8F" size="-2"> 115 </font>} lhslh;
<font color="8FBC8F" size="-2"> 116 </font>
<font color="8FBC8F" size="-2"> 117 </font>typedef struct lhslh_server {
<font color="8FBC8F" size="-2"> 118 </font> lhslh* client; /* BAD! */
<font color="8FBC8F" size="-2"> 119 </font> bat batid;
<font color="8FBC8F" size="-2"> 120 </font> int my_number;
<font color="8FBC8F" size="-2"> 121 </font>} lhslh_server;
<font color="8FBC8F" size="-2"> 122 </font>
<font color="8FBC8F" size="-2"> 123 </font>
</font></pre>
<br><hr size=5 noshade><br><a name=mod_2_1_0>
<h4>2.1 Handy macros</h4>This is some handy macros for structure elements access
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.h</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 129 </font>
<font color="8FBC8F" size="-2"> 130 </font>#define GETID(lhslh) ((lhslh)->id)
<font color="8FBC8F" size="-2"> 131 </font>#define GETLEVEL(lhslh) ((lhslh)->level)
<font color="8FBC8F" size="-2"> 132 </font>#define GETNEXT_TO_SPLIT(lhslh) ((lhslh)->split)
<font color="8FBC8F" size="-2"> 133 </font>#define GETmapping(lhslh) ((lhslh)->mappingid)
<font color="8FBC8F" size="-2"> 134 </font>#define GETMAPPING(lhslh) (BATdescriptor(GETmapping(lhslh)))
<font color="8FBC8F" size="-2"> 135 </font>
<font color="8FBC8F" size="-2"> 136 </font>
<font color="8FBC8F" size="-2"> 137 </font>#define GETbat(lhslh_s) ((lhslh_s)->batid)
<font color="8FBC8F" size="-2"> 138 </font>#define GETBAT(lhslh_s) (BATdescriptor(GETbat(lhslh_s)))
<font color="8FBC8F" size="-2"> 139 </font>#define GETCLIENT(lhslh_s) ((lhslh_s)->client)
<font color="8FBC8F" size="-2"> 140 </font>#define GETMY_NUMBER(lhslh_s) ((lhslh_s)->my_number)
<font color="8FBC8F" size="-2"> 141 </font>
<font color="8FBC8F" size="-2"> 142 </font>#endif /* __LHSLH_H__ */
</font></pre>
The atom slot-in functions.
<br>
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.m</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 146 </font>
<font color="8FBC8F" size="-2"> 147 </font> ATOM lhslh[16, 0];
<font color="8FBC8F" size="-2"> 148 </font> TOSTR = lhslh_tostr;
<font color="8FBC8F" size="-2"> 149 </font> FROMSTR = lhslh_fromstr;
<font color="8FBC8F" size="-2"> 150 </font> COMP = lhslh_compare;
<font color="8FBC8F" size="-2"> 151 </font> HASH = lhslh_hash;
<font color="8FBC8F" size="-2"> 152 </font> NULL = lhslh_null;
<font color="8FBC8F" size="-2"> 153 </font> END;
</font></pre>
<br><a name=mod_2_1_1>
<h5><b>2.1.1 LH*lh Server Data</b></h5>
The server specific data is stored in the lhslh_server atom.
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.m</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 158 </font>
<font color="8FBC8F" size="-2"> 159 </font> ATOM lhslh_server[12, 0];
<font color="8FBC8F" size="-2"> 160 </font> TOSTR = lhslh_server_tostr;
<font color="8FBC8F" size="-2"> 161 </font> FROMSTR = lhslh_server_fromstr;
<font color="8FBC8F" size="-2"> 162 </font> COMP = lhslh_server_compare;
<font color="8FBC8F" size="-2"> 163 </font> HASH = lhslh_server_hash;
<font color="8FBC8F" size="-2"> 164 </font> NULL = lhslh_server_null;
<font color="8FBC8F" size="-2"> 165 </font> END;
<font color="8FBC8F" size="-2"> 166 </font>
<font color="8FBC8F" size="-2"> 167 </font>
</font></pre>
<hr size=5 noshade><br><a name=mod_2_2_0>
<h4>2.2 Command Declarations</h4>
It is assumed that the SDDS-file already exists (at some server). The
handle, a means of access to the data in the file, is given by calling
the function LHSLH(ID, NAME)
The file must currently be created at a server node with
LHSLH_NEW(HEADTYPE, TAILTYPE), the structure is returned. File
parameters are set using SPLIT_AT(LHSLH, COUNT). COUNT determines at
what point the file should be split. Another measure is to set the
maximum memory usage using SPLIT_SIZE(LHSLH, BYTES).
<br><a name=mod_2_2_1>
<h5><b>2.2.1 Admin</b></h5>
Client side functions
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.m</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 182 </font>
<font color="8FBC8F" size="-2"> 183 </font>COMMAND lhslh_open(int id, any home): lhslh = lhslh_open;
<font color="8FBC8F" size="-2"> 184 </font> "open a handle to a SDDS (LH*) named ID/int at SERVER/int"
<font color="8FBC8F" size="-2"> 185 </font>
<font color="8FBC8F" size="-2"> 186 </font>COMMAND close(lhslh) = lhslh_close;
<font color="8FBC8F" size="-2"> 187 </font> "close the HANDLE/lhslh"
<font color="8FBC8F" size="-2"> 188 </font>
<font color="8FBC8F" size="-2"> 189 </font>COMMAND "destroy"(lhslh f) = lhslh_destroy;
<font color="8FBC8F" size="-2"> 190 </font> "kills the whole file, the question is if the client should
<font color="8FBC8F" size="-2"> 191 </font> be able to do this?"
<font color="8FBC8F" size="-2"> 192 </font>
</font></pre>
<p>Server side functions.
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.m</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 196 </font>
<font color="8FBC8F" size="-2"> 197 </font>COMMAND lhslh_server_new(int h, int t, int id, any home, int my_number): lhslh_server = lhslh_server_new;
<font color="8FBC8F" size="-2"> 198 </font> "creates an lhslh table at this node."
<font color="8FBC8F" size="-2"> 199 </font>
</font></pre>
<br><a name=mod_2_2_2>
<h5><b>2.2.2 Info</b></h5>
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.m</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 202 </font>
<font color="8FBC8F" size="-2"> 203 </font>COMMAND level(lhslh): int = lhslh_level;
<font color="8FBC8F" size="-2"> 204 </font> "the client image of the level of the SDDS"
<font color="8FBC8F" size="-2"> 205 </font>
<font color="8FBC8F" size="-2"> 206 </font>COMMAND next_to_split(lhslh): int = lhslh_next_to_split;
<font color="8FBC8F" size="-2"> 207 </font> "the client image of the next server to split of the named SDDS"
<font color="8FBC8F" size="-2"> 208 </font>
<font color="8FBC8F" size="-2"> 209 </font>COMMAND mapping_ref(lhslh): bat[int, int] = lhslh_mapping_ref;
<font color="8FBC8F" size="-2"> 210 </font> "returns a (reference to a) BAT containing the mapping from logical
<font color="8FBC8F" size="-2"> 211 </font> local number (to the SDDS) to a global number (identity)."
<font color="8FBC8F" size="-2"> 212 </font>
<font color="8FBC8F" size="-2"> 213 </font>COMMAND address(lhslh, any): int = lhslh_address;
<font color="8FBC8F" size="-2"> 214 </font> "calculates the address for data of KEY, for a client"
<font color="8FBC8F" size="-2"> 215 </font>
<font color="8FBC8F" size="-2"> 216 </font>COMMAND address(lhslh_server, any): int = lhslh_server_address;
<font color="8FBC8F" size="-2"> 217 </font> "calculates the address for data of KEY, at a server"
<font color="8FBC8F" size="-2"> 218 </font>
<font color="8FBC8F" size="-2"> 219 </font>COMMAND id(lhslh): int = lhslh_id;
<font color="8FBC8F" size="-2"> 220 </font> "returns the id of the file"
<font color="8FBC8F" size="-2"> 221 </font>
<font color="8FBC8F" size="-2"> 222 </font>COMMAND my_number(lhslh_server s): int = lhslh_server_my_number;
<font color="8FBC8F" size="-2"> 223 </font> "the logical number of the server s for the LH*LH-file"
<font color="8FBC8F" size="-2"> 224 </font>COMMAND my_number(lhslh_server s, int) = lhslh_server_my_number_set;
<font color="8FBC8F" size="-2"> 225 </font> "set it"
<font color="8FBC8F" size="-2"> 226 </font>
<font color="8FBC8F" size="-2"> 227 </font>COMMAND split_at(lhslh_server s): int = lhslh_split_at;
<font color="8FBC8F" size="-2"> 228 </font> "get the number of items that the server should split at"
<font color="8FBC8F" size="-2"> 229 </font>COMMAND split_at(lhslh_server s, int at) = lhslh_split_at_set;
<font color="8FBC8F" size="-2"> 230 </font> "set the number of items that the server should split at"
<font color="8FBC8F" size="-2"> 231 </font>
<font color="8FBC8F" size="-2"> 232 </font>COMMAND client(lhslh_server s): lhslh = lhslh_server_client;
<font color="8FBC8F" size="-2"> 233 </font> "get the handle to the client structure from a server."
<font color="8FBC8F" size="-2"> 234 </font>
<font color="8FBC8F" size="-2"> 235 </font>COMMAND bat_ref(lhslh_server s): bat[any, any] = lhslh_server_bat_ref;
<font color="8FBC8F" size="-2"> 236 </font> "get the handle to the bat for the server."
<font color="8FBC8F" size="-2"> 237 </font>
</font></pre>
<br><a name=mod_2_2_3>
<h5><b>2.2.3 Modifiers</b></h5>
Client side
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.m</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 241 </font>
<font color="8FBC8F" size="-2"> 242 </font>COMMAND update_image(lhslh, int level, int next) = lhslh_update_image;
<font color="8FBC8F" size="-2"> 243 </font> "returns an up-to-date atom for the client image of FILE with LEVEL and SPLITP. \\
<font color="8FBC8F" size="-2"> 244 </font> NOTE: The returned/modified atom should be inserted into a table otherwise it
<font color="8FBC8F" size="-2"> 245 </font> will be forgotten."
<font color="8FBC8F" size="-2"> 246 </font>
<font color="8FBC8F" size="-2"> 247 </font>COMMAND outdated_image_Q(lhslh, int level, int next) = lhslh_outdated_image;
<font color="8FBC8F" size="-2"> 248 </font> "returns true if the first image is considered to be outdated
<font color="8FBC8F" size="-2"> 249 </font> compared to the the second given image. The given image is assumed
<font color="8FBC8F" size="-2"> 250 </font> to be the 'official' of the data structure. In the case of LH*LH only
<font color="8FBC8F" size="-2"> 251 </font> the level is transferred from the second image. The client is
<font color="8FBC8F" size="-2"> 252 </font> not allowed to use what server the response the answer came from
<font color="8FBC8F" size="-2"> 253 </font> (see Jonas S Karlsson's Licentiate Eng. Theses)."
<font color="8FBC8F" size="-2"> 254 </font>
</font></pre>
<br><a name=mod_2_2_4>
<h5><b>2.2.4 BAT style interface</b></h5>
Client side
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.m</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 258 </font>COMMAND "insert"(lhslh f, any h, any t) : bit = lhslh_insert_h_t;
<font color="8FBC8F" size="-2"> 259 </font> "client insert in the distributed bat LH*LH-file f an BUN with head h and tail t"
<font color="8FBC8F" size="-2"> 260 </font>
<font color="8FBC8F" size="-2"> 261 </font>COMMAND "insert"(lhslh f, bat[any, any]) = lhslh_insert_bat;
<font color="8FBC8F" size="-2"> 262 </font> "client insert in the LH*LH-file f the items in the bat."
<font color="8FBC8F" size="-2"> 263 </font>
<font color="8FBC8F" size="-2"> 264 </font>COMMAND "delete"(lhslh f, any::1 h): bat[any::1, any] = lhslh_delete_h;
<font color="8FBC8F" size="-2"> 265 </font> "client delete BUNs stored in LH*LH-file f, with head h."
<font color="8FBC8F" size="-2"> 266 </font>
</font></pre>
<p>Server side
<br><a name=mod_2_2_5>
<h5><b>2.2.5 Selectors/Operators</b></h5>
<br><a name=mod_2_2_6>
<h5><b>2.2.6 BAT style interface</b></h5>
Server side
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.m</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 277 </font>COMMAND select(lhslh f, any::1 low, any::1 high): bat[any, any::1] = lhslh_select_l_h;
<font color="8FBC8F" size="-2"> 278 </font> "a text"
<font color="8FBC8F" size="-2"> 279 </font>COMMAND select(lhslh f, any::1): bat[any, any::1] = lhslh_select_eq;
<font color="8FBC8F" size="-2"> 280 </font> "they only select on tails???"
<font color="8FBC8F" size="-2"> 281 </font>COMMAND sample(lhslh f, int num): bat[any::1,any::2] = lhslh_sample;
<font color="8FBC8F" size="-2"> 282 </font> "Produce a random selection of size 'num' from the input BAT."
<font color="8FBC8F" size="-2"> 283 </font>
</font></pre>
<br><a name=mod_2_2_7>
<h5><b>2.2.7 Joins</b></h5>
<br><a name=mod_2_2_8>
<h5><b>2.2.8 Aggregates</b></h5>
# this bat keeps track of all the clients interface atoms that
# this Monet instance knows about, they are shared both for
# SDDS server/clients.
# this bat keeps track of the different servers/buckets stored at
# this Monet instance (server).
source(\"/ufs/jonas/Src/Module/lhs/machines.mil\");
# if (client.need_updating_Q(server.client)) {
# sender.rpc(\"update_image\", client, server.official_image);
# }
<br>
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.m</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 302 </font>
<font color="8FBC8F" size="-2"> 303 </font> LOAD = "
<font color="8FBC8F" size="-2"> 304 </font>";
<font color="8FBC8F" size="-2"> 305 </font>
</font></pre>
<hr size=5 noshade><br><a name=mod_2_3_0>
<h4>2.3 Server side functions</h4>
These are server side functions, to be called remotely
common arguments:
SENDER : Includes id of sender/reqid can be used to reply
CLIENT : The client atom lhslh/rpsrp or whatever.
It contains at least all information
we need from the client side for IAMs.
...parameters
These functions assume that the servers data is stored
in something that behaves like a bat. That is operations
like .insert a.s.o. are defined upon the /ref_bat/s result.
if an RPC funtion returns it first argument, then
this should be interpreted as /no result/ - Send no
result back. The result from the query does then
come from another sender than the one who orignally
got the query.
How should a program that want to do queries
look like? Explicit code sent out? I still
think query execution is a dataflow issue.
the data comes from somewhere and should end up
somewhere, possible not the same. This more or
less means that /the data should know where to
go/.
this means that a /query plan/ with input & output pipes
should be sent. Actually into a pipe should go first
indata, /program/, outputing statements that distribute
the data to where it is needed together maybe with a /program/.
Sort of continuation based...
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.m</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 341 </font>
<font color="8FBC8F" size="-2"> 342 </font>END sdds;
<font color="8FBC8F" size="-2"> 343 </font>
<font color="8FBC8F" size="-2"> 344 </font>
</font></pre>
<hr size=5 noshade><hr size=5 noshade><br><br><a name=mod_3_0_0>
<h2>3 Methods for lhslh </h2>
<hr size=5 noshade><br><a name=mod_3_1_0>
<h4>3.1 General Includes</h4><p>C
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.c</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 353 </font>#include <stdlib.h>
<font color="8FBC8F" size="-2"> 354 </font>#include <math.h>
<font color="8FBC8F" size="-2"> 355 </font>#include <limits.h>
</font></pre>
<p>Monet
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.c</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 359 </font>#include <gdk.h>
<font color="8FBC8F" size="-2"> 360 </font>#include <monet.h>
</font></pre>
<p>SDDS
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.c</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 364 </font>#include "sdds.h"
<font color="8FBC8F" size="-2"> 365 </font>#include "sdds.proto.h"
</font></pre>
<p>LH*LH
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.c</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 369 </font>#include "LHS/hash.h"
<font color="8FBC8F" size="-2"> 370 </font>
</font></pre>
<p>More handy things, like arbitrary constants...
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.c</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 374 </font>
<font color="8FBC8F" size="-2"> 375 </font>#define LHSLH_INITIAL_BAT_SIZE 16
<font color="8FBC8F" size="-2"> 376 </font>#define LHSLH_INITIAL_MAPPING_SIZE 16
<font color="8FBC8F" size="-2"> 377 </font>#define TOSTRING_SIZE 64 /* I don't like this, unsafe (sprintf) */
<font color="8FBC8F" size="-2"> 378 </font>
</font></pre>
<br><a name=mod_3_1_1>
<h5><b>3.1.1 General need</b></h5>
GDKmemsure ensures that (void*) MEMORY, (int*) LENGTH bytes, can contain a structure of
at least NEED bytes. If to small/NULL/unspecified, the memory is GDKfreed, and the reallocated
with GDKmalloc according to the specified needs. If non-NULL length, then it is set
to the actual length.
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.c</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 387 </font>void *GDKmemsure(void *mem, int *len, int need)
<font color="8FBC8F" size="-2"> 388 </font>{
<font color="8FBC8F" size="-2"> 389 </font> if (mem && (!len || (*len < need))) { /* To small or no lenght spec. */
<font color="8FBC8F" size="-2"> 390 </font> GDKfree(mem); mem = NULL;
<font color="8FBC8F" size="-2"> 391 </font> }
<font color="8FBC8F" size="-2"> 392 </font> if (!mem) { /* no mem (maby it was to small) */
<font color="8FBC8F" size="-2"> 393 </font> mem = GDKmalloc(need);
<font color="8FBC8F" size="-2"> 394 </font> if (len) *len = need;
<font color="8FBC8F" size="-2"> 395 </font> }
<font color="8FBC8F" size="-2"> 396 </font> return mem;
<font color="8FBC8F" size="-2"> 397 </font>}
<font color="8FBC8F" size="-2"> 398 </font>
<font color="8FBC8F" size="-2"> 399 </font>
</font></pre>
<br><a name=mod_3_1_2>
<h5><b>3.1.2 Monet ATOMS required operators</b></h5>
<br><a name=mod_3_1_3>
<h5><b>3.1.3 LH*lh Client Image</b></h5>
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.c</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 404 </font>
<font color="8FBC8F" size="-2"> 405 </font>static lhslh lhslh_nil = { 0 };
<font color="8FBC8F" size="-2"> 406 </font>
<font color="8FBC8F" size="-2"> 407 </font>int lhslh_tostr(str *s, int *l, lhslh *h)
<font color="8FBC8F" size="-2"> 408 </font>{
<font color="8FBC8F" size="-2"> 409 </font> char *buf;
<font color="8FBC8F" size="-2"> 410 </font> *s = (str) GDKmemsure(*s, l, TOSTRING_SIZE);
<font color="8FBC8F" size="-2"> 411 </font> buf = *s;
<font color="8FBC8F" size="-2"> 412 </font> sprintf(buf, "<lhslh %d: L=%d, P=%d>",
<font color="8FBC8F" size="-2"> 413 </font> GETID(h), GETLEVEL(h), GETNEXT_TO_SPLIT(h));
<font color="8FBC8F" size="-2"> 414 </font> return strlen(buf);
<font color="8FBC8F" size="-2"> 415 </font>}
<font color="8FBC8F" size="-2"> 416 </font>
<font color="8FBC8F" size="-2"> 417 </font>int lhslh_fromstr(str s, int *l, lhslh **h)
<font color="8FBC8F" size="-2"> 418 </font>{
<font color="8FBC8F" size="-2"> 419 </font> int id, level, p, len;
<font color="8FBC8F" size="-2"> 420 </font>
<font color="8FBC8F" size="-2"> 421 </font> if (sscanf(s, "<lhslh %d: L=%d, P=%d>%n", &id, &level, &p, &len) == 3) {
<font color="8FBC8F" size="-2"> 422 </font> if( *h == NULL || (*l) < (int)sizeof(lhslh)) {
<font color="8FBC8F" size="-2"> 423 </font> /* Should one not do a GDKfree here if *h is no null? */
<font color="8FBC8F" size="-2"> 424 </font> *h = (lhslh *)GDKmalloc(sizeof(lhslh));
<font color="8FBC8F" size="-2"> 425 </font> *l = sizeof(lhslh);
<font color="8FBC8F" size="-2"> 426 </font> GETID(*h)=id;
<font color="8FBC8F" size="-2"> 427 </font> GETLEVEL(*h)=level;
<font color="8FBC8F" size="-2"> 428 </font> GETNEXT_TO_SPLIT(*h)=p;
<font color="8FBC8F" size="-2"> 429 </font> }
<font color="8FBC8F" size="-2"> 430 </font> return len; /* Characters consumed */
<font color="8FBC8F" size="-2"> 431 </font> }
<font color="8FBC8F" size="-2"> 432 </font> return 0; /* failed */
<font color="8FBC8F" size="-2"> 433 </font>}
<font color="8FBC8F" size="-2"> 434 </font>
<font color="8FBC8F" size="-2"> 435 </font>int lhslh_hash( lhslh *h )
<font color="8FBC8F" size="-2"> 436 </font>{
<font color="8FBC8F" size="-2"> 437 </font> return GETID(h); /* Not the best but... */
<font color="8FBC8F" size="-2"> 438 </font>}
<font color="8FBC8F" size="-2"> 439 </font>
<font color="8FBC8F" size="-2"> 440 </font>lhslh* lhslh_null( void )
<font color="8FBC8F" size="-2"> 441 </font>{
<font color="8FBC8F" size="-2"> 442 </font> return &lhslh_nil;
<font color="8FBC8F" size="-2"> 443 </font>}
<font color="8FBC8F" size="-2"> 444 </font>
<font color="8FBC8F" size="-2"> 445 </font>int lhslh_compare ( lhslh *h1, lhslh *h2 )
<font color="8FBC8F" size="-2"> 446 </font>{
<font color="8FBC8F" size="-2"> 447 </font> return (GETID(h1)!=GETID(h2));
<font color="8FBC8F" size="-2"> 448 </font>}
<font color="8FBC8F" size="-2"> 449 </font>
</font></pre>
<br><a name=mod_3_1_4>
<h5><b>3.1.4 LH*lh Server Data</b></h5>
[ To be filled in ]
lhslh_server_tostring & lhslh_server_fromstr are not "good".
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.c</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 455 </font>
<font color="8FBC8F" size="-2"> 456 </font>static lhslh_server lhslh_server_nil = { 0 };
<font color="8FBC8F" size="-2"> 457 </font>
<font color="8FBC8F" size="-2"> 458 </font>int lhslh_server_tostr(str *s, int *l, lhslh_server *h)
<font color="8FBC8F" size="-2"> 459 </font>{
<font color="8FBC8F" size="-2"> 460 </font> char *buf;
<font color="8FBC8F" size="-2"> 461 </font>
<font color="8FBC8F" size="-2"> 462 </font> *s = (str) GDKmemsure(*s, l, TOSTRING_SIZE);
<font color="8FBC8F" size="-2"> 463 </font> buf = *s;
<font color="8FBC8F" size="-2"> 464 </font> sprintf(buf, "<lhslh_server %d.%d: L=%d, P=%d>",
<font color="8FBC8F" size="-2"> 465 </font> GETID(GETCLIENT(h)), GETMY_NUMBER(h), GETLEVEL(GETCLIENT(h)), GETNEXT_TO_SPLIT(GETCLIENT(h)));
<font color="8FBC8F" size="-2"> 466 </font> return strlen(buf);
<font color="8FBC8F" size="-2"> 467 </font>}
<font color="8FBC8F" size="-2"> 468 </font>
<font color="8FBC8F" size="-2"> 469 </font>int lhslh_server_fromstr(str s, int *l, lhslh_server **h)
<font color="8FBC8F" size="-2"> 470 </font>{
<font color="8FBC8F" size="-2"> 471 </font> int id, level, p, len;
<font color="8FBC8F" size="-2"> 472 </font>
<font color="8FBC8F" size="-2"> 473 </font> if (sscanf(s, "<lhslh_server %d: L=%d, P=%d>%n", &id, &level, &p, &len) == 3) {
<font color="8FBC8F" size="-2"> 474 </font> if( *h == NULL || (*l) < (int)sizeof(lhslh)) {
<font color="8FBC8F" size="-2"> 475 </font> /* Should one not do a GDKfree here if *h is no null? */
<font color="8FBC8F" size="-2"> 476 </font> *h = (lhslh_server *)GDKmalloc(sizeof(lhslh_server));
<font color="8FBC8F" size="-2"> 477 </font> *l = sizeof(lhslh_server);
<font color="8FBC8F" size="-2"> 478 </font> GETID(GETCLIENT(*h)) = id;
<font color="8FBC8F" size="-2"> 479 </font> GETLEVEL(GETCLIENT(*h)) = level;
<font color="8FBC8F" size="-2"> 480 </font> GETNEXT_TO_SPLIT(GETCLIENT(*h)) = p;
<font color="8FBC8F" size="-2"> 481 </font> }
<font color="8FBC8F" size="-2"> 482 </font> return len; /* Characters consumed */
<font color="8FBC8F" size="-2"> 483 </font> }
<font color="8FBC8F" size="-2"> 484 </font> return 0; /* failed */
<font color="8FBC8F" size="-2"> 485 </font>}
<font color="8FBC8F" size="-2"> 486 </font>
<font color="8FBC8F" size="-2"> 487 </font>int lhslh_server_hash( lhslh_server *h )
<font color="8FBC8F" size="-2"> 488 </font>{
<font color="8FBC8F" size="-2"> 489 </font> return GETID(GETCLIENT(h));
<font color="8FBC8F" size="-2"> 490 </font>}
<font color="8FBC8F" size="-2"> 491 </font>
<font color="8FBC8F" size="-2"> 492 </font>lhslh_server* lhslh_server_null( void )
<font color="8FBC8F" size="-2"> 493 </font>{
<font color="8FBC8F" size="-2"> 494 </font> return &lhslh_server_nil;
<font color="8FBC8F" size="-2"> 495 </font>}
<font color="8FBC8F" size="-2"> 496 </font>
</font></pre>
<p>Differens between comp/compare?
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.c</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 500 </font>
<font color="8FBC8F" size="-2"> 501 </font>int lhslh_server_compare ( lhslh_server *h1, lhslh_server *h2 )
<font color="8FBC8F" size="-2"> 502 </font>{
<font color="8FBC8F" size="-2"> 503 </font> return (GETID(GETCLIENT(h1))!=GETID(GETCLIENT(h2)));
<font color="8FBC8F" size="-2"> 504 </font>}
<font color="8FBC8F" size="-2"> 505 </font>
</font></pre>
<hr size=5 noshade><br><a name=mod_3_2_0>
<h4>3.2 Actual Command Implementation</h4>
<br><a name=mod_3_2_1>
<h5><b>3.2.1 Admin</b></h5>
Client side functions
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.c</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 511 </font>
<font color="8FBC8F" size="-2"> 512 </font>int lhslh_open(lhslh *res, int *id, ptr home, int home_tp)
<font color="8FBC8F" size="-2"> 513 </font>{
<font color="8FBC8F" size="-2"> 514 </font> printf("sizeof lhslh = %d\n", sizeof(lhslh));
<font color="8FBC8F" size="-2"> 515 </font> printf("sizeof lhslh_server = %d\n", sizeof(lhslh_server));
<font color="8FBC8F" size="-2"> 516 </font>
<font color="8FBC8F" size="-2"> 517 </font> GETID(res) = *id;
<font color="8FBC8F" size="-2"> 518 </font> GETLEVEL(res) = 0;
<font color="8FBC8F" size="-2"> 519 </font> GETNEXT_TO_SPLIT(res) = 0;
<font color="8FBC8F" size="-2"> 520 </font> {
<font color="8FBC8F" size="-2"> 521 </font> BAT* b = BATnew(TYPE_int, TYPE_int, LHSLH_INITIAL_MAPPING_SIZE);
<font color="8FBC8F" size="-2"> 522 </font> GETmapping(res) = BBPcacheid(b);
<font color="8FBC8F" size="-2"> 523 </font> BBPfix(GETmapping(res));
<font color="8FBC8F" size="-2"> 524 </font> }
<font color="8FBC8F" size="-2"> 525 </font> /* serverhome not used, should be stored in a bat
<font color="8FBC8F" size="-2"> 526 </font> and we keep a ref to the bat from here! */
<font color="8FBC8F" size="-2"> 527 </font> return GDK_SUCCEED;
<font color="8FBC8F" size="-2"> 528 </font>}
<font color="8FBC8F" size="-2"> 529 </font>
<font color="8FBC8F" size="-2"> 530 </font>int lhslh_close(lhslh *h)
<font color="8FBC8F" size="-2"> 531 </font>{
<font color="8FBC8F" size="-2"> 532 </font> return GDK_SUCCEED;
<font color="8FBC8F" size="-2"> 533 </font>}
<font color="8FBC8F" size="-2"> 534 </font>
<font color="8FBC8F" size="-2"> 535 </font>int lhslh_destroy(lhslh *h)
<font color="8FBC8F" size="-2"> 536 </font>{
<font color="8FBC8F" size="-2"> 537 </font> return GDK_SUCCEED;
<font color="8FBC8F" size="-2"> 538 </font>}
<font color="8FBC8F" size="-2"> 539 </font>
</font></pre>
<p>Server side functions.
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.c</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 543 </font>
<font color="8FBC8F" size="-2"> 544 </font>int
<font color="8FBC8F" size="-2"> 545 </font>lhslh_server_new(
<font color="8FBC8F" size="-2"> 546 </font> lhslh_server* retval, /* put return atom here. */
<font color="8FBC8F" size="-2"> 547 </font> int* h, /* pointer to integer.*/
<font color="8FBC8F" size="-2"> 548 </font> int* t, /* pointer to integer.*/
<font color="8FBC8F" size="-2"> 549 </font> int* id,
<font color="8FBC8F" size="-2"> 550 </font> ptr home,
<font color="8FBC8F" size="-2"> 551 </font> int home_tp,
<font color="8FBC8F" size="-2"> 552 </font> int* my_number
<font color="8FBC8F" size="-2"> 553 </font>)
<font color="8FBC8F" size="-2"> 554 </font>{
<font color="8FBC8F" size="-2"> 555 </font> BAT* b = BATnew(*h, *t, LHSLH_INITIAL_BAT_SIZE);
<font color="8FBC8F" size="-2"> 556 </font> b = BATmode(b, PERSISTENT); /* OR PERMANENT??? */
<font color="8FBC8F" size="-2"> 557 </font> GETbat(retval) = BBPcacheid(b);
<font color="8FBC8F" size="-2"> 558 </font> BBPfix(GETbat(retval));
<font color="8FBC8F" size="-2"> 559 </font> {
<font color="8FBC8F" size="-2"> 560 </font> char name[1024];
<font color="8FBC8F" size="-2"> 561 </font>
<font color="8FBC8F" size="-2"> 562 </font> sprintf(name, "sdds_%d_%d", *id, *my_number);
<font color="8FBC8F" size="-2"> 563 </font> BATrename(b, name);
<font color="8FBC8F" size="-2"> 564 </font> }
</font></pre>
This is funny by the way, since we might have several "servers" for the same SDDS-file
on the same Mserver. Should we still store CLIENT-information per "server" or per
Mserver (database)? How would a better influence the SDDS: LH*(lh)? Guesses:
For servers operations not at all. But the updating schema could have to be
different, but all clients would benefit from a better image. (The problem might
lie in a splitting server).
<br>
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.c</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 573 </font> GETCLIENT(retval) = GDKmalloc(sizeof(lhslh)); /* should be stored in a bat? It may*/
<font color="8FBC8F" size="-2"> 574 </font> GETMY_NUMBER(retval) = *my_number;
<font color="8FBC8F" size="-2"> 575 </font> return lhslh_open(GETCLIENT(retval), id, home, home_tp);
<font color="8FBC8F" size="-2"> 576 </font>}
<font color="8FBC8F" size="-2"> 577 </font>
</font></pre>
<br><a name=mod_3_2_2>
<h5><b>3.2.2 Info</b></h5>
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.c</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 580 </font>
<font color="8FBC8F" size="-2"> 581 </font>int lhslh_level(int *res, lhslh *h)
<font color="8FBC8F" size="-2"> 582 </font>{
<font color="8FBC8F" size="-2"> 583 </font> *res = GETLEVEL(h);
<font color="8FBC8F" size="-2"> 584 </font> return GDK_SUCCEED;
<font color="8FBC8F" size="-2"> 585 </font>}
<font color="8FBC8F" size="-2"> 586 </font>
<font color="8FBC8F" size="-2"> 587 </font>int lhslh_next_to_split(int *res, lhslh *h)
<font color="8FBC8F" size="-2"> 588 </font>{
<font color="8FBC8F" size="-2"> 589 </font> *res = GETNEXT_TO_SPLIT(h);
<font color="8FBC8F" size="-2"> 590 </font> return GDK_SUCCEED;
<font color="8FBC8F" size="-2"> 591 </font>}
<font color="8FBC8F" size="-2"> 592 </font>
<font color="8FBC8F" size="-2"> 593 </font>int lhslh_mapping_ref(BAT **bat, lhslh *h)
<font color="8FBC8F" size="-2"> 594 </font>{
<font color="8FBC8F" size="-2"> 595 </font> *bat = GETMAPPING(h);
<font color="8FBC8F" size="-2"> 596 </font> return GDK_SUCCEED;
<font color="8FBC8F" size="-2"> 597 </font>}
<font color="8FBC8F" size="-2"> 598 </font>
<font color="8FBC8F" size="-2"> 599 </font>/* #define ATOMhash_correct(typ, key, max) ((unsigned)BATatoms[typ].atomHash(key, max)) */
<font color="8FBC8F" size="-2"> 600 </font>
<font color="8FBC8F" size="-2"> 601 </font>int lhslh_address(int *res, lhslh *h, void *key, int typ)
<font color="8FBC8F" size="-2"> 602 </font>{
<font color="8FBC8F" size="-2"> 603 </font> /* *res = 4711+typ; stupid variant to test */
<font color="8FBC8F" size="-2"> 604 </font> if (!(BATatoms[typ].atomHash)) {
<font color="8FBC8F" size="-2"> 605 </font> printf("lhslh_address: There is no hash-function for GDK type = %d\n", typ);
<font color="8FBC8F" size="-2"> 606 </font> *res = -1;
<font color="8FBC8F" size="-2"> 607 </font>
<font color="8FBC8F" size="-2"> 608 </font> return GDK_FAIL;
<font color="8FBC8F" size="-2"> 609 </font> }
<font color="8FBC8F" size="-2"> 610 </font> *res = AddressOfKey(ATOMhash(typ, key), GETLEVEL(h), GETNEXT_TO_SPLIT(h));
<font color="8FBC8F" size="-2"> 611 </font> printf("lhslh_address finished *res = %d\n", *res);
<font color="8FBC8F" size="-2"> 612 </font> return GDK_SUCCEED;
<font color="8FBC8F" size="-2"> 613 </font>}
<font color="8FBC8F" size="-2"> 614 </font>
<font color="8FBC8F" size="-2"> 615 </font>int lhslh_server_address(int *res, lhslh_server *h, void *key, int typ)
<font color="8FBC8F" size="-2"> 616 </font>{
<font color="8FBC8F" size="-2"> 617 </font> *res = ServerAddrCalc(GETMY_NUMBER(h), ATOMhash(typ, key),
<font color="8FBC8F" size="-2"> 618 </font> GETLEVEL(GETCLIENT(h)));
<font color="8FBC8F" size="-2"> 619 </font> return GDK_SUCCEED;
<font color="8FBC8F" size="-2"> 620 </font>}
<font color="8FBC8F" size="-2"> 621 </font>
<font color="8FBC8F" size="-2"> 622 </font>
<font color="8FBC8F" size="-2"> 623 </font>int lhslh_server_client(lhslh *client, lhslh_server *h)
<font color="8FBC8F" size="-2"> 624 </font>{
<font color="8FBC8F" size="-2"> 625 </font> *client = *GETCLIENT(h);
<font color="8FBC8F" size="-2"> 626 </font> return GDK_SUCCEED;
<font color="8FBC8F" size="-2"> 627 </font>}
<font color="8FBC8F" size="-2"> 628 </font>
<font color="8FBC8F" size="-2"> 629 </font>int lhslh_server_bat_ref(BAT **bat, lhslh_server *h)
<font color="8FBC8F" size="-2"> 630 </font>{
<font color="8FBC8F" size="-2"> 631 </font> *bat = GETBAT(h);
<font color="8FBC8F" size="-2"> 632 </font> return GDK_SUCCEED;
<font color="8FBC8F" size="-2"> 633 </font>}
<font color="8FBC8F" size="-2"> 634 </font>
</font></pre>
<br><a name=mod_3_2_3>
<h5><b>3.2.3 Modifiers</b></h5>
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.c</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 637 </font>
<font color="8FBC8F" size="-2"> 638 </font>/* #include "../tcpip/tcpip.h" */
<font color="8FBC8F" size="-2"> 639 </font>
<font color="8FBC8F" size="-2"> 640 </font>#include "../tcpip/tcpip.h" /* Hmm, copied file... (BAD) */
<font color="8FBC8F" size="-2"> 641 </font>
</font></pre>
Updates should also require that the sdds_servers should be
updated if needed. That is more mappings from logical number to
names of physical machines should be added.
<br>
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.c</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 649 </font>int lhslh_update_image(lhslh* h, int* level, int* next)
<font color="8FBC8F" size="-2"> 650 </font>{
<font color="8FBC8F" size="-2"> 651 </font> GETLEVEL(h) = *level;
<font color="8FBC8F" size="-2"> 652 </font> GETNEXT_TO_SPLIT(h) = *next;
<font color="8FBC8F" size="-2"> 653 </font> return GDK_SUCCEED;
<font color="8FBC8F" size="-2"> 654 </font>}
<font color="8FBC8F" size="-2"> 655 </font>
<font color="8FBC8F" size="-2"> 656 </font>int lhslh_outdated_image(lhslh* h, int* level, int* next)
<font color="8FBC8F" size="-2"> 657 </font>{
<font color="8FBC8F" size="-2"> 658 </font> GETLEVEL(h) = *level;
<font color="8FBC8F" size="-2"> 659 </font> GETNEXT_TO_SPLIT(h) = *next;
<font color="8FBC8F" size="-2"> 660 </font> return GDK_SUCCEED;
<font color="8FBC8F" size="-2"> 661 </font>}
<font color="8FBC8F" size="-2"> 662 </font>
</font></pre>
Addressing nodes is a difficult issue. There are three differnt
types of addresses:
<ul>
<li> Logical (LH*)
<li> Virtual (logical machine)
<li> Physical (machine IP-address)
</ul><br>The logical addresses are the ones calculated by an SDDS they
span [0..n-1] wheren n is the number of servers employed. This
under the assumption that there is a linear growth (or a mapping
to a linear scale) for the used SDDS algorithm.<br>The function mapping_ref(lhslh) returns the virtual address for
an logical address per LH* structure. This mapping might vary
between different invocations of the database system.<br>The virtual addresses (machine OIDs) are decided at bucket allocation
time. A server of an SDDS can be a server for many buckets from the
same or other SDDS relations (files). For SDDSs using the same key for
distribution they might share the same/similar mapping_ref.
A global BAT contains the mapping from a virtual address (OID) to
a physical machine by means of an "internet-address".<br>One of the reasons for using virtual addresses is that of recoverbility;
If a server for some reason gets disconnected from the others,
a decision can be made to let another node take over the load
or use a spare node; Another reason is that at one run, a certain
number of workstation might be availiable and at another run
a different number. Then this mapping could serve as the mean
of not having to redistribute the data because of different environment,
it should work anyway. It also allows dynamic redistribution. Just change
and distribute the mapping.<br>An example:
<pre>a.SDDS-log : 0, 1, 2, 3, 4, 5, 6, 7
a.mach-virt: 1, 2, 3, 1, 2, 3, 1, 2
b.SDDS-log : 0, 1, 2, 3, 4, 5, 6, 7
b.mach-virt: 1, 2, 3, 1, 2, 3, 1, 2
c.SDDS-log : 0, 1, 2, 3, 4, 5, 6, 7
c.mach-virt: 4, 5, 4, 5, 4, 5, 4, 5
mach-phys : 1 -- skiff, 2 -- pinas, 3 -- stomer, 4,5 -- skiff:4711, 4712
</pre>
a) and b) use the same distribution because they are indexed on
the same key, this clusters "objects".<br>c), however, uses a different distribution, at the moment giving
allocated to two virtual nodes (4, 5) that both happends to be
the same physcical nod (skiff)! But they use two different ports,
thus two threads, and enables two requests to be handled at the same time!
The two threads are guaranteed to use different sets of data.<br>Question: How much overhead does it impose to let a server handle
several "independent" buckets compared to the exact match of number
of buckets? How does it affect "load" (as amount of used storage,
execution throughput).<br>
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.c</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 727 </font>
<font color="8FBC8F" size="-2"> 728 </font>int lhslh_log2virt(int* log, lhslh *h, int *virt)
<font color="8FBC8F" size="-2"> 729 </font>{
<font color="8FBC8F" size="-2"> 730 </font> *log = 0; /* Fallback case! should always work! */
<font color="8FBC8F" size="-2"> 731 </font>
<font color="8FBC8F" size="-2"> 732 </font> *log = *virt; /* for testing */
<font color="8FBC8F" size="-2"> 733 </font> return GDK_SUCCEED;
<font color="8FBC8F" size="-2"> 734 </font>}
<font color="8FBC8F" size="-2"> 735 </font>
<font color="8FBC8F" size="-2"> 736 </font>int lhslh_virt2phys(int* phys, int *virt)
<font color="8FBC8F" size="-2"> 737 </font>{
<font color="8FBC8F" size="-2"> 738 </font> *phys = -1;
<font color="8FBC8F" size="-2"> 739 </font> return GDK_SUCCEED;
<font color="8FBC8F" size="-2"> 740 </font>}
<font color="8FBC8F" size="-2"> 741 </font>
</font></pre>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 743 </font>int
<font color="8FBC8F" size="-2"> 744 </font>lhslh_insert_bat(
<font color="8FBC8F" size="-2"> 745 </font> lhslh* f, /* pointer to user-defined atom.*/
<font color="8FBC8F" size="-2"> 746 </font> BAT* bat /* pointer to BAT[any,any] record.*/
<font color="8FBC8F" size="-2"> 747 </font>)
<font color="8FBC8F" size="-2"> 748 </font>{
<font color="8FBC8F" size="-2"> 749 </font> return GDK_FAIL;
<font color="8FBC8F" size="-2"> 750 </font>}
<font color="8FBC8F" size="-2"> 751 </font>
<font color="8FBC8F" size="-2"> 752 </font>int fix_address(lhslh *h, int logical) { /* log -> virt -> phys -> connhandle */
<font color="8FBC8F" size="-2"> 753 </font> int virt, phys;
<font color="8FBC8F" size="-2"> 754 </font> int zelf = 0;
<font color="8FBC8F" size="-2"> 755 </font> ptr *res;
<font color="8FBC8F" size="-2"> 756 </font> int *res_tp;
<font color="8FBC8F" size="-2"> 757 </font>
<font color="8FBC8F" size="-2"> 758 </font> RFC(res, res_tp, zelf, "log2comm",
<font color="8FBC8F" size="-2"> 759 </font> TPE(h, lhslh); TPE(&logical, int););
<font color="8FBC8F" size="-2"> 760 </font> return *((int*) res);
<font color="8FBC8F" size="-2"> 761 </font>}
<font color="8FBC8F" size="-2"> 762 </font>
<font color="8FBC8F" size="-2"> 763 </font>
<font color="8FBC8F" size="-2"> 764 </font>int
<font color="8FBC8F" size="-2"> 765 </font>lhslh_insert_h_t(
<font color="8FBC8F" size="-2"> 766 </font> bit* retval, /* put return atom here. */
<font color="8FBC8F" size="-2"> 767 </font> lhslh* f, /* pointer to user-defined atom.*/
<font color="8FBC8F" size="-2"> 768 </font> ptr h, /* ANY parameter: pointer to some atom.*/
<font color="8FBC8F" size="-2"> 769 </font> int h_tp, /* type number of previous parameter.*/
<font color="8FBC8F" size="-2"> 770 </font> ptr t, /* ANY parameter: pointer to some atom.*/
<font color="8FBC8F" size="-2"> 771 </font> int t_tp /* type number of previous parameter.*/
<font color="8FBC8F" size="-2"> 772 </font>)
<font color="8FBC8F" size="-2"> 773 </font>{
<font color="8FBC8F" size="-2"> 774 </font> ptr *res;
<font color="8FBC8F" size="-2"> 775 </font> int *res_tp;
<font color="8FBC8F" size="-2"> 776 </font> char buf[256];
<font color="8FBC8F" size="-2"> 777 </font> int zero = 0;
<font color="8FBC8F" size="-2"> 778 </font>
<font color="8FBC8F" size="-2"> 779 </font> RFC(res, res_tp, 0 /* fix */, "sdds_insert",
<font color="8FBC8F" size="-2"> 780 </font> tINT(&zero);
<font color="8FBC8F" size="-2"> 781 </font> tVAL(f);
<font color="8FBC8F" size="-2"> 782 </font> tARG(h, h_tp);
<font color="8FBC8F" size="-2"> 783 </font> tARG(t, t_tp));
<font color="8FBC8F" size="-2"> 784 </font>
<font color="8FBC8F" size="-2"> 785 </font> /*
<font color="8FBC8F" size="-2"> 786 </font> sprintf(name, "sdds.find(%i).bat_ref.insert", GETID(f));
<font color="8FBC8F" size="-2"> 787 </font> RFC(res, res_tp, name, ARG(h, h_tp); ARG(t, t_tp));
<font color="8FBC8F" size="-2"> 788 </font> */
<font color="8FBC8F" size="-2"> 789 </font> return GDK_SUCCEED;
<font color="8FBC8F" size="-2"> 790 </font>}
<font color="8FBC8F" size="-2"> 791 </font>
<font color="8FBC8F" size="-2"> 792 </font>int
<font color="8FBC8F" size="-2"> 793 </font>lhslh_delete_h(
<font color="8FBC8F" size="-2"> 794 </font> BAT** retval, /* put pointer to BAT[any,any] record here. */
<font color="8FBC8F" size="-2"> 795 </font> lhslh* f, /* pointer to user-defined atom.*/
<font color="8FBC8F" size="-2"> 796 </font> ptr h, /* ANY parameter: pointer to some atom.*/
<font color="8FBC8F" size="-2"> 797 </font> int h_tp /* type number of previous parameter.*/
<font color="8FBC8F" size="-2"> 798 </font>)
<font color="8FBC8F" size="-2"> 799 </font>{
<font color="8FBC8F" size="-2"> 800 </font> return GDK_SUCCEED;
<font color="8FBC8F" size="-2"> 801 </font>}
<font color="8FBC8F" size="-2"> 802 </font>
</font></pre>
<br><a name=mod_3_2_4>
<h5><b>3.2.4 Selectors/Operators</b></h5>
<hr size=1 noshade><table width="100%"><tr><td align=right valign=top><font size="-1"><i>sdds.c</i></font></td></tr></table>
<pre><font size="-1" color="#505050"><font color="8FBC8F" size="-2"> 805 </font>
<font color="8FBC8F" size="-2"> 806 </font>int
<font color="8FBC8F" size="-2"> 807 </font>lhslh_select_eq(
<font color="8FBC8F" size="-2"> 808 </font> BAT** retval, /* put pointer to BAT[any,any] record here. */
<font color="8FBC8F" size="-2"> 809 </font> lhslh* f, /* pointer to user-defined atom.*/
<font color="8FBC8F" size="-2"> 810 </font> ptr Void1, /* ANY parameter: pointer to some atom.*/
<font color="8FBC8F" size="-2"> 811 </font> int Tpe1 /* type number of previous parameter.*/
<font color="8FBC8F" size="-2"> 812 </font>)
<font color="8FBC8F" size="-2"> 813 </font>{
<font color="8FBC8F" size="-2"> 814 </font> return GDK_SUCCEED;
<font color="8FBC8F" size="-2"> 815 </font>}
<font color="8FBC8F" size="-2"> 816 </font>
<font color="8FBC8F" size="-2"> 817 </font>int
<font color="8FBC8F" size="-2"> 818 </font>lhslh_select_l_h(
<font color="8FBC8F" size="-2"> 819 </font> BAT** retval, /* put pointer to BAT[any,any] record here. */
<font color="8FBC8F" size="-2"> 820 </font> lhslh* f, /* pointer to user-defined atom.*/
<font color="8FBC8F" size="-2"> 821 </font> ptr low, /* ANY parameter: pointer to some atom.*/
<font color="8FBC8F" size="-2"> 822 </font> int low_tp, /* type number of previous parameter.*/
<font color="8FBC8F" size="-2"> 823 </font> ptr high, /* ANY parameter: pointer to some atom.*/
<font color="8FBC8F" size="-2"> 824 </font> int high_tp /* type number of previous parameter.*/
<font color="8FBC8F" size="-2"> 825 </font>)
<font color="8FBC8F" size="-2"> 826 </font>{
<font color="8FBC8F" size="-2"> 827 </font> return GDK_SUCCEED;
<font color="8FBC8F" size="-2"> 828 </font>}
<font color="8FBC8F" size="-2"> 829 </font>
<font color="8FBC8F" size="-2"> 830 </font>int
<font color="8FBC8F" size="-2"> 831 </font>lhslh_sample(
<font color="8FBC8F" size="-2"> 832 </font> BAT** retval, /* put pointer to BAT[any,any] record here. */
<font color="8FBC8F" size="-2"> 833 </font> lhslh* f, /* pointer to user-defined atom.*/
<font color="8FBC8F" size="-2"> 834 </font> int* num /* pointer to integer.*/
<font color="8FBC8F" size="-2"> 835 </font>)
<font color="8FBC8F" size="-2"> 836 </font>{
<font color="8FBC8F" size="-2"> 837 </font> return GDK_SUCCEED;
<font color="8FBC8F" size="-2"> 838 </font>}
<font color="8FBC8F" size="-2"> 839 </font>
<font color="8FBC8F" size="-2"> 840 </font>
</font></pre>
<br><a name=mod_3_2_5>
<h5><b>3.2.5 Joins</b></h5>
<br><a name=mod_3_2_6>
<h5><b>3.2.6 Aggregates</b></h5>
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