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Diffstat (limited to 'src/exchangedb/versioning.sql')
| -rw-r--r-- | src/exchangedb/versioning.sql | 294 |
1 files changed, 294 insertions, 0 deletions
diff --git a/src/exchangedb/versioning.sql b/src/exchangedb/versioning.sql new file mode 100644 index 000000000..444cf95ed --- /dev/null +++ b/src/exchangedb/versioning.sql @@ -0,0 +1,294 @@ +-- LICENSE AND COPYRIGHT +-- +-- Copyright (C) 2010 Hubert depesz Lubaczewski +-- +-- This program is distributed under the (Revised) BSD License: +-- L<http://www.opensource.org/licenses/bsd-license.php> +-- +-- Redistribution and use in source and binary forms, with or without +-- modification, are permitted provided that the following conditions +-- are met: +-- +-- * Redistributions of source code must retain the above copyright +-- notice, this list of conditions and the following disclaimer. +-- +-- * Redistributions in binary form must reproduce the above copyright +-- notice, this list of conditions and the following disclaimer in the +-- documentation and/or other materials provided with the distribution. +-- +-- * Neither the name of Hubert depesz Lubaczewski's Organization +-- nor the names of its contributors may be used to endorse or +-- promote products derived from this software without specific +-- prior written permission. +-- +-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +-- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +-- IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +-- DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE +-- FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +-- DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR +-- SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER +-- CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, +-- OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +-- OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +-- +-- Code origin: https://gitlab.com/depesz/Versioning/blob/master/install.versioning.sql +-- +-- +-- # NAME +-- +-- **Versioning** - simplistic take on tracking and applying changes to databases. +-- +-- # DESCRIPTION +-- +-- This project strives to provide simple way to manage changes to +-- database. +-- +-- Instead of making changes on development server, then finding +-- differences between production and development, deciding which ones +-- should be installed on production, and finding a way to install them - +-- you start with writing diffs themselves! +-- +-- # INSTALLATION +-- +-- To install versioning simply run install.versioning.sql in your database +-- (all of them: production, stage, test, devel, ...). +-- +-- # USAGE +-- +-- In your files with patches to database, put whole logic in single +-- transaction, and use \_v.\* functions - usually \_v.register_patch() at +-- least to make sure everything is OK. +-- +-- For example. Let's assume you have patch files: +-- +-- ## 0001.sql: +-- +-- ``` +-- create table users (id serial primary key, username text); +-- ``` +-- +-- ## 0002.sql: +-- +-- ``` +-- insert into users (username) values ('depesz'); +-- ``` +-- To change it to use versioning you would change the files, to this +-- state: +-- +-- 0000.sql: +-- +-- ``` +-- BEGIN; +-- select _v.register_patch('000-base', NULL, NULL); +-- create table users (id serial primary key, username text); +-- COMMIT; +-- ``` +-- +-- ## 0002.sql: +-- +-- ``` +-- BEGIN; +-- select _v.register_patch('001-users', ARRAY['000-base'], NULL); +-- insert into users (username) values ('depesz'); +-- COMMIT; +-- ``` +-- +-- This will make sure that patch 001-users can only be applied after +-- 000-base. +-- +-- # AVAILABLE FUNCTIONS +-- +-- ## \_v.register_patch( TEXT ) +-- +-- Registers named patch, or dies if it is already registered. +-- +-- Returns integer which is id of patch in \_v.patches table - only if it +-- succeeded. +-- +-- ## \_v.register_patch( TEXT, TEXT[] ) +-- +-- Same as \_v.register_patch( TEXT ), but checks is all given patches (given as +-- array in second argument) are already registered. +-- +-- ## \_v.register_patch( TEXT, TEXT[], TEXT[] ) +-- +-- Same as \_v.register_patch( TEXT, TEXT[] ), but also checks if there are no conflicts with preexisting patches. +-- +-- Third argument is array of names of patches that conflict with current one. So +-- if any of them is installed - register_patch will error out. +-- +-- ## \_v.unregister_patch( TEXT ) +-- +-- Removes information about given patch from the versioning data. +-- +-- It doesn't remove objects that were created by this patch - just removes +-- metainformation. +-- +-- ## \_v.assert_user_is_superuser() +-- +-- Make sure that current patch is being loaded by superuser. +-- +-- If it's not - it will raise exception, and break transaction. +-- +-- ## \_v.assert_user_is_not_superuser() +-- +-- Make sure that current patch is not being loaded by superuser. +-- +-- If it is - it will raise exception, and break transaction. +-- +-- ## \_v.assert_user_is_one_of(TEXT, TEXT, ... ) +-- +-- Make sure that current patch is being loaded by one of listed users. +-- +-- If ```current_user``` is not listed as one of arguments - function will raise +-- exception and break the transaction. + +BEGIN; + + +-- This file adds versioning support to database it will be loaded to. +-- It requires that PL/pgSQL is already loaded - will raise exception otherwise. +-- All versioning "stuff" (tables, functions) is in "_v" schema. + +-- All functions are defined as 'RETURNS SETOF INT4' to be able to make them to RETURN literally nothing (0 rows). +-- >> RETURNS VOID<< IS similar, but it still outputs "empty line" in psql when calling +CREATE SCHEMA IF NOT EXISTS _v; +COMMENT ON SCHEMA _v IS 'Schema for versioning data and functionality.'; + +CREATE TABLE IF NOT EXISTS _v.patches ( + patch_name TEXT PRIMARY KEY, + applied_tsz TIMESTAMPTZ NOT NULL DEFAULT now(), + applied_by TEXT NOT NULL, + requires TEXT[], + conflicts TEXT[] +); +COMMENT ON TABLE _v.patches IS 'Contains information about what patches are currently applied on database.'; +COMMENT ON COLUMN _v.patches.patch_name IS 'Name of patch, has to be unique for every patch.'; +COMMENT ON COLUMN _v.patches.applied_tsz IS 'When the patch was applied.'; +COMMENT ON COLUMN _v.patches.applied_by IS 'Who applied this patch (PostgreSQL username)'; +COMMENT ON COLUMN _v.patches.requires IS 'List of patches that are required for given patch.'; +COMMENT ON COLUMN _v.patches.conflicts IS 'List of patches that conflict with given patch.'; + +CREATE OR REPLACE FUNCTION _v.register_patch( IN in_patch_name TEXT, IN in_requirements TEXT[], in_conflicts TEXT[], OUT versioning INT4 ) RETURNS setof INT4 AS $$ +DECLARE + t_text TEXT; + t_text_a TEXT[]; + i INT4; +BEGIN + -- Thanks to this we know only one patch will be applied at a time + LOCK TABLE _v.patches IN EXCLUSIVE MODE; + + SELECT patch_name INTO t_text FROM _v.patches WHERE patch_name = in_patch_name; + IF FOUND THEN + RAISE EXCEPTION 'Patch % is already applied!', in_patch_name; + END IF; + + t_text_a := ARRAY( SELECT patch_name FROM _v.patches WHERE patch_name = any( in_conflicts ) ); + IF array_upper( t_text_a, 1 ) IS NOT NULL THEN + RAISE EXCEPTION 'Versioning patches conflict. Conflicting patche(s) installed: %.', array_to_string( t_text_a, ', ' ); + END IF; + + IF array_upper( in_requirements, 1 ) IS NOT NULL THEN + t_text_a := '{}'; + FOR i IN array_lower( in_requirements, 1 ) .. array_upper( in_requirements, 1 ) LOOP + SELECT patch_name INTO t_text FROM _v.patches WHERE patch_name = in_requirements[i]; + IF NOT FOUND THEN + t_text_a := t_text_a || in_requirements[i]; + END IF; + END LOOP; + IF array_upper( t_text_a, 1 ) IS NOT NULL THEN + RAISE EXCEPTION 'Missing prerequisite(s): %.', array_to_string( t_text_a, ', ' ); + END IF; + END IF; + + INSERT INTO _v.patches (patch_name, applied_tsz, applied_by, requires, conflicts ) VALUES ( in_patch_name, now(), current_user, coalesce( in_requirements, '{}' ), coalesce( in_conflicts, '{}' ) ); + RETURN; +END; +$$ language plpgsql; +COMMENT ON FUNCTION _v.register_patch( TEXT, TEXT[], TEXT[] ) IS 'Function to register patches in database. Raises exception if there are conflicts, prerequisites are not installed or the migration has already been installed.'; + +CREATE OR REPLACE FUNCTION _v.register_patch( TEXT, TEXT[] ) RETURNS setof INT4 AS $$ + SELECT _v.register_patch( $1, $2, NULL ); +$$ language sql; +COMMENT ON FUNCTION _v.register_patch( TEXT, TEXT[] ) IS 'Wrapper to allow registration of patches without conflicts.'; +CREATE OR REPLACE FUNCTION _v.register_patch( TEXT ) RETURNS setof INT4 AS $$ + SELECT _v.register_patch( $1, NULL, NULL ); +$$ language sql; +COMMENT ON FUNCTION _v.register_patch( TEXT ) IS 'Wrapper to allow registration of patches without requirements and conflicts.'; + +CREATE OR REPLACE FUNCTION _v.unregister_patch( IN in_patch_name TEXT, OUT versioning INT4 ) RETURNS setof INT4 AS $$ +DECLARE + i INT4; + t_text_a TEXT[]; +BEGIN + -- Thanks to this we know only one patch will be applied at a time + LOCK TABLE _v.patches IN EXCLUSIVE MODE; + + t_text_a := ARRAY( SELECT patch_name FROM _v.patches WHERE in_patch_name = ANY( requires ) ); + IF array_upper( t_text_a, 1 ) IS NOT NULL THEN + RAISE EXCEPTION 'Cannot uninstall %, as it is required by: %.', in_patch_name, array_to_string( t_text_a, ', ' ); + END IF; + + DELETE FROM _v.patches WHERE patch_name = in_patch_name; + GET DIAGNOSTICS i = ROW_COUNT; + IF i < 1 THEN + RAISE EXCEPTION 'Patch % is not installed, so it can''t be uninstalled!', in_patch_name; + END IF; + + RETURN; +END; +$$ language plpgsql; +COMMENT ON FUNCTION _v.unregister_patch( TEXT ) IS 'Function to unregister patches in database. Dies if the patch is not registered, or if unregistering it would break dependencies.'; + +CREATE OR REPLACE FUNCTION _v.assert_patch_is_applied( IN in_patch_name TEXT ) RETURNS TEXT as $$ +DECLARE + t_text TEXT; +BEGIN + SELECT patch_name INTO t_text FROM _v.patches WHERE patch_name = in_patch_name; + IF NOT FOUND THEN + RAISE EXCEPTION 'Patch % is not applied!', in_patch_name; + END IF; + RETURN format('Patch %s is applied.', in_patch_name); +END; +$$ language plpgsql; +COMMENT ON FUNCTION _v.assert_patch_is_applied( TEXT ) IS 'Function that can be used to make sure that patch has been applied.'; + +CREATE OR REPLACE FUNCTION _v.assert_user_is_superuser() RETURNS TEXT as $$ +DECLARE + v_super bool; +BEGIN + SELECT usesuper INTO v_super FROM pg_user WHERE usename = current_user; + IF v_super THEN + RETURN 'assert_user_is_superuser: OK'; + END IF; + RAISE EXCEPTION 'Current user is not superuser - cannot continue.'; +END; +$$ language plpgsql; +COMMENT ON FUNCTION _v.assert_user_is_superuser() IS 'Function that can be used to make sure that patch is being applied using superuser account.'; + +CREATE OR REPLACE FUNCTION _v.assert_user_is_not_superuser() RETURNS TEXT as $$ +DECLARE + v_super bool; +BEGIN + SELECT usesuper INTO v_super FROM pg_user WHERE usename = current_user; + IF v_super THEN + RAISE EXCEPTION 'Current user is superuser - cannot continue.'; + END IF; + RETURN 'assert_user_is_not_superuser: OK'; +END; +$$ language plpgsql; +COMMENT ON FUNCTION _v.assert_user_is_not_superuser() IS 'Function that can be used to make sure that patch is being applied using normal (not superuser) account.'; + +CREATE OR REPLACE FUNCTION _v.assert_user_is_one_of(VARIADIC p_acceptable_users TEXT[] ) RETURNS TEXT as $$ +DECLARE +BEGIN + IF current_user = any( p_acceptable_users ) THEN + RETURN 'assert_user_is_one_of: OK'; + END IF; + RAISE EXCEPTION 'User is not one of: % - cannot continue.', p_acceptable_users; +END; +$$ language plpgsql; +COMMENT ON FUNCTION _v.assert_user_is_one_of(TEXT[]) IS 'Function that can be used to make sure that patch is being applied by one of defined users.'; + +COMMIT; |