pgsql: Add support for COPY TO callback functions
Add support for COPY TO callback functions
This is useful as a way for extensions to process COPY TO rows in the
way they see fit (say auditing, analytics, backend, etc.) without the
need to invoke an external process running as the OS user running the
backend through PROGRAM that requires superuser rights. COPY FROM
already provides a similar callback for logical replication. For COPY
TO, the callback is triggered when we are ready to send a row in
CopySendEndOfRow(), which is the same code path as when sending a row
to a frontend or a pipe/file.
A small test module, test_copy_callbacks, is added to provide some
coverage for this facility.
Author: Bilva Sanaba, Nathan Bossart
Discussion: /messages/by-id/253C21D1-FCEB-41D9-A2AF-E6517015B7D7@amazon.com
Branch
------
master
Details
-------
https://git.postgresql.org/pg/commitdiff/9fcdf2c787ac6da330165ea3cd50ec5155943a2b
Modified Files
--------------
src/backend/commands/copy.c | 2 +-
src/backend/commands/copyto.c | 31 +++++++++++--
src/include/commands/copy.h | 3 +-
src/test/modules/Makefile | 1 +
src/test/modules/meson.build | 1 +
src/test/modules/test_copy_callbacks/.gitignore | 4 ++
src/test/modules/test_copy_callbacks/Makefile | 23 ++++++++++
.../expected/test_copy_callbacks.out | 13 ++++++
src/test/modules/test_copy_callbacks/meson.build | 34 +++++++++++++++
.../sql/test_copy_callbacks.sql | 4 ++
.../test_copy_callbacks--1.0.sql | 8 ++++
.../test_copy_callbacks/test_copy_callbacks.c | 51 ++++++++++++++++++++++
.../test_copy_callbacks.control | 4 ++
src/tools/pgindent/typedefs.list | 1 +
14 files changed, 175 insertions(+), 5 deletions(-)
Hi,
On 2022-10-11 02:47:56 +0000, Michael Paquier wrote:
Add support for COPY TO callback functions
This is useful as a way for extensions to process COPY TO rows in the
way they see fit (say auditing, analytics, backend, etc.) without the
need to invoke an external process running as the OS user running the
backend through PROGRAM that requires superuser rights. COPY FROM
already provides a similar callback for logical replication. For COPY
TO, the callback is triggered when we are ready to send a row in
CopySendEndOfRow(), which is the same code path as when sending a row
to a frontend or a pipe/file.A small test module, test_copy_callbacks, is added to provide some
coverage for this facility.
New warning with msvc 2022:
C:\dev\postgres-meson\src\test\modules\test_copy_callbacks\test_copy_callbacks.c(40,73): warning C4047: 'function': 'bool' differs in levels of indirection from 'void *' [C:\dev\postgres-meson\build-msbuild-2022\src\test\modules\test_copy_callbacks\7d667bc@@test_copy_callbacks@sha.vcxproj]
C:\dev\postgres-meson\src\test\modules\test_copy_callbacks\test_copy_callbacks.c(40,69): warning C4024: 'BeginCopyTo': different types for formal and actual parameter 6 [C:\dev\postgres-meson\build-msbuild-2022\src\test\modules\test_copy_callbacks\7d667bc@@test_copy_callbacks@sha.vcxproj]
Looks quite justified. Passing NULL to bool is_program isn't right.
Greetings,
Andres Freund