From 4c8df9e1c898876865f557681371b52baab970e9 Mon Sep 17 00:00:00 2001 From: Hans Bolinder Date: Tue, 22 Nov 2016 15:50:50 +0100 Subject: stdlib: Remove support for Dets version 8 tables When at it, types have been added to record fields. --- lib/stdlib/doc/src/dets.xml | 61 ++++++++++----------------------------------- 1 file changed, 13 insertions(+), 48 deletions(-) (limited to 'lib/stdlib/doc/src') diff --git a/lib/stdlib/doc/src/dets.xml b/lib/stdlib/doc/src/dets.xml index 2e4261d72e..eb6e32aecf 100644 --- a/lib/stdlib/doc/src/dets.xml +++ b/lib/stdlib/doc/src/dets.xml @@ -100,18 +100,12 @@ provided by Dets, neither is the limited support for concurrent updates that makes a sequence of first and next calls safe to use on fixed ETS tables. Both these - features will be provided by Dets in a future release of + features may be provided by Dets in a future release of Erlang/OTP. Until then, the Mnesia application (or some user-implemented method for locking) must be used to implement safe concurrency. Currently, no Erlang/OTP library has support for ordered disk-based term storage.

-

Two versions of the format used for storing objects on file are - supported by Dets. The first version, 8, is the format always used - for tables created by Erlang/OTP R7 and earlier. The second version, 9, - is the default version of tables created by Erlang/OTP R8 (and later - releases). Erlang/OTP R8 can create version 8 tables, and convert version - 8 tables to version 9, and conversely, upon request.

All Dets functions return {error, Reason} if an error occurs (first/1 and next/2 are exceptions, they @@ -190,9 +184,6 @@ - - - @@ -385,18 +376,13 @@

{bchunk_format, binary()} - An opaque binary describing the format of the objects returned by bchunk/2. The binary can be used as argument to - is_compatible_chunk_format/2. Only available for - version 9 tables.

+ is_compatible_chunk_format/2.

{hash, Hash} - Describes which BIF is used to calculate the hash values of the objects stored in the Dets table. Possible values of Hash:

- -

hash - Implies that the erlang:hash/2 BIF - is used.

-

phash - Implies that the erlang:phash/2 BIF is used.

@@ -413,8 +399,7 @@

{no_keys, integer >= 0()} - The number of different - keys stored in the table. Only available for version 9 - tables.

+ keys stored in the table.

{no_objects, integer >= 0()} - The number of objects @@ -424,8 +409,7 @@

{no_slots, {Min, Used, Max}} - The number of slots of the table. Min is the minimum number of slots, Used is the number of currently used slots, - and Max is the maximum number of slots. Only - available for version 9 tables.

+ and Max is the maximum number of slots.

{owner, pid()} - The pid of the process that @@ -466,10 +450,6 @@ time warp safe. Time warp safe code must use safe_fixed_monotonic_time instead.

 - -

{version, integer()} - The version of the format of - the table.

- @@ -662,8 +642,8 @@ ok objects at a time, until at least one object matches or the end of the table is reached. The default, indicated by giving N the value default, is to let - the number of objects vary depending on the sizes of the objects. If - Name is a version 9 table, all objects with the + the number of objects vary depending on the sizes of the objects. + All objects with the same key are always matched at the same time, which implies that more than N objects can sometimes be matched.

The table is always to be protected using @@ -743,9 +723,9 @@ ok end of the table is reached. The default, indicated by giving N the value default, is to let the number - of objects vary depending on the sizes of the objects. If - Name is a version 9 table, all matching objects - with the same key are always returned in the same reply, which implies + of objects vary depending on the sizes of the objects. All + matching objects with the same key are always returned + in the same reply, which implies that more than N objects can sometimes be returned.

The table is always to be protected using safe_fixtable/2 @@ -842,8 +822,7 @@ ok maximal value. Notice that a higher value can increase the table fragmentation, and a smaller value can decrease the fragmentation, at - the expense of execution time. Only available for version - 9 tables.

+ the expense of execution time.

{min_no_slots, @@ -880,12 +859,7 @@ ok FileName}} is returned if the table must be repaired.

Value force means that a reparation is made even if the table is properly closed. - This is how to convert tables created by older versions of - STDLIB. An example is tables hashed with the deprecated - erlang:hash/2 BIF. Tables created with Dets from - STDLIB version 1.8.2 or later use function - erlang:phash/2 or function erlang:phash2/1, - which is preferred.

+ This is a seldom needed option.

Option repair is ignored if the table is already open.

 @@ -893,15 +867,6 @@ ok type()} - The table type. Defaults to set.

 - -

{version, - version()} - The version of the format - used for the table. Defaults to 9. Tables on the format - used before Erlang/OTP R8 can be created by specifying value - 8. A version 8 table can be converted to a version 9 - table by specifying options {version,9} - and {repair,force}.

- @@ -1041,8 +1006,8 @@ ok a time, until at least one object matches or the end of the table is reached. The default, indicated by giving N the value default, is to let the number - of objects vary depending on the sizes of the objects. If - Name is a version 9 table, all objects with the + of objects vary depending on the sizes of the objects. All + objects with the same key are always handled at the same time, which implies that the match specification can be applied to more than N objects.

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