ETS retrieve all objects before deleting the table

[Frank Muller]

Hi Valentin,

Have you read what I posted in earlier messages?
I already explored first/next with other alternatives.

Thanks anyway

/F.


> In addition to serialisation to disk (its:tab2file/2,3), one can always
> use:
>
> *ets:first/1* followed by a number of  calls to *ets:next/2*
>
>
> e.g.
>         ets:first( Tab ) -> Key
> ets:lookup( Tab, Key ) -> [TableRow] % to retrieve data associated with
> this key
>         ets:next( Tab, Key ) -> NextKey, etc.
>
> NOTE: once the end of the table is reached, instead of a key an atom
> ‘$end_of_table’ is returned by ets:next/2.
>
>
> On 19 Jan 2022, at 23:33, valentin@REDACTED <valentin@REDACTED>
> wrote:
>
> To serialize ETS to a file on the disk, one may use ets:tab2file/2,3.
>
> It does not destroy the table, but simply dumps a content of the table to
> a file. I’ve used it a number of times and it works as advertised.
> I don’t think there’s a tool available to traverse this file without
> loading it back to ETS (via ets:file2tab/1,2).
>
> However, it may be a start.
>
>
> V/
>
>
>
>
> On 18 Jan 2022, at 17:02, Hugo Mills <hugo@REDACTED> wrote:
>
>  I may be wrong, but my reading of Frank's requirement was that the
> table needs to be serialised to disk in some external format so that
> it can be processed by some additional tool outside the current erlang
> application. No amount of reparenting to another erlang process in the
> same VM is going to accomplish that...
>
>  Hugo.
>
> On Tue, Jan 18, 2022 at 03:49:51PM +0200, Led wrote:
>
>
> I think this opinion stems from confusion about the GiftData argument
> in ets:give_away/3.
>
> AFAIK this just passes whatever 'data' you set for the variable, not
> the actual table data, through to the recipient of the 'ETS_TRANSFER'
> message.
>
>
> It gives all table data with full access to the process "for
> processing". What else do you need?
>
>
> On Tue, Jan 18, 2022 at 7:28 AM Frank Muller <frank.muller.erl@REDACTED>
> wrote:
>
>
> No it doesn’t. It only charges the table owner
>
>
>
>
> I’d like to retrieve all objects before deleting the table.
>
>
> Strange task. Table is already "all objects".
>
>
>
> Nothing strange. Just a simple requirement.
> Objects are sent elsewhere for processing before deleting the table
> content.
>
>
> What’s the most efficient way to do it?
>
>
> ets:give_away/3
>
>
>
> That’s strange indeed. How give_away/3 could help? It gives the ownership
> to another proc.
>
>
> It actually sends all objects elsewhere (to another proc) for processing.
>
>
> --
> Hugo Mills             | All hope abandon, Ye who press Enter here.
> hugo@REDACTED carfax.org.uk |
> http://carfax.org.uk/  |
> PGP: E2AB1DE4          |
>
>
>
>
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