snmpa_local_db(3)

📦

version 29.0.6 · 3 versions

💖 snmpa_local_db — the SNMP built-in database, but make it make sense 💖

okay bestie, you're looking at snmpa_local_db(3), an Erlang module definition from the snmp crew. Let's get into it 🫶

✨ NAME ✨

snmpa_local_db — the SNMP built-in database. yes she's built-in, yes she's serving, no she's not perfect. we'll get there.

🌸 DESCRIPTION 🌸

so snmpa_local_db is the module holding all the functions you need to implement tables (and variables, don't forget the variables) using the SNMP built-in database. 💅

this database exists in two instances, and you gotta pick your fighter:

one volatile, implemented with ets
one persistent, implemented with dets

⚠️ real talk: there is a scaling problem with this database.

Insertions and deletions are inefficient for large tables. 😭

and the fix? the glow-up? use Mnesia instead. that's the whole rec, no cap.

okay so the functions below describe the interface to snmpa_local_db, and every single one of them has a Mnesia equivalent. the argument NameDb is a tuple {Name, Db} where Name is the symbolic name of the managed object (as defined in the MIB), and Db is either volatile or persistent. and listen — mnesia is not possible here, because all of these functions are snmpa_local_db specific. periodt. 🙅

🎀 Common Data Types

in the functions defined below, the following limitation applies:

Db = volatile | persistent

👀 See Also

ets(3), dets(3), snmp_generic(3)

🔥 FUNCTIONS 🔥

`dump() -> ok | {error, Reason}` when `Reason :: term().`

use this one to manually dump the database to file. like you, doing it by hand, iconic. 💅

`match(Table, Pattern) -> [Match]` when `Table :: snmpa:name_db() | snmpa:name()`, `Pattern :: ets:match_pattern()`, `Match :: term().`

performs an ets/dets matching on the table. ✨

for a description of Pattern and the return values, go peek at ets:match/2 — she explains it better than I ever could.

`print(Table, Db) -> term()` when `Table :: snmpa:name()`, `Db :: volatile | persistent.`

prints the contents of the database on screen. this one is so useful for debugging, fr fr, because the STANDARD-MIB and OTP-SNMPEA-MIB (and maybe your own MIBs too, main character energy) are stored in snmpa_local_db. 👑

Table is an atom for a table in the database. when no name is supplied, the whole database is shown. the whole thing. she's showing everything. 🙈

😭 okay important caveat: note that these functions do not actually print, using io:format/2 — instead they (just) return the information. if you execute it in a shell, the information will then be displayed (probably truncated) there. so like... the shell is doing the printing, not her. she's just handing you the goods.

a better use would be:

io:format("~p~n", [snmpa_local_db:print()]).

yes bestie, wrap her. 🎀

`table_create(Table) -> boolean()` when `Table :: snmpa:name_db() | snmpa:name().`

creates a table. but heads up — if the table already exists, the old copy is destroyed. 💀 gone. reduced to atoms.

returns false if the NameDb argument is incorrectly specified, true otherwise.