From 92eab334ce94b4e5e8dba5189ce2ffbecdeb67e6 Mon Sep 17 00:00:00 2001 From: Nathan Bossart Date: Fri, 27 Jan 2023 21:57:13 -0800 Subject: [PATCH 3/4] restructure archive module API --- contrib/basic_archive/basic_archive.c | 13 +++++++++---- src/backend/postmaster/pgarch.c | 18 ++++++++--------- src/backend/postmaster/shell_archive.c | 14 ++++++++----- src/include/postmaster/archive_module.h | 26 ++++++++++--------------- 4 files changed, 36 insertions(+), 35 deletions(-) diff --git a/contrib/basic_archive/basic_archive.c b/contrib/basic_archive/basic_archive.c index 87bbb2174d..1655f72b5b 100644 --- a/contrib/basic_archive/basic_archive.c +++ b/contrib/basic_archive/basic_archive.c @@ -49,6 +49,12 @@ static void basic_archive_file_internal(const char *file, const char *path); static bool check_archive_directory(char **newval, void **extra, GucSource source); static bool compare_files(const char *file1, const char *file2); +static const ArchiveModuleCallbacks basic_archive_callbacks = { + .check_configured_cb = basic_archive_configured, + .archive_file_cb = basic_archive_file, + .shutdown_cb = NULL +}; + /* * _PG_init * @@ -78,13 +84,12 @@ _PG_init(void) * * Returns the module's archiving callbacks. */ -void -_PG_archive_module_init(ArchiveModuleCallbacks *cb) +const ArchiveModuleCallbacks * +_PG_archive_module_init(void) { AssertVariableIsOfType(&_PG_archive_module_init, ArchiveModuleInit); - cb->check_configured_cb = basic_archive_configured; - cb->archive_file_cb = basic_archive_file; + return &basic_archive_callbacks; } /* diff --git a/src/backend/postmaster/pgarch.c b/src/backend/postmaster/pgarch.c index eca02d5e74..627c579f0e 100644 --- a/src/backend/postmaster/pgarch.c +++ b/src/backend/postmaster/pgarch.c @@ -98,7 +98,7 @@ char *XLogArchiveLibrary = ""; */ static time_t last_sigterm_time = 0; static PgArchData *PgArch = NULL; -static ArchiveModuleCallbacks ArchiveCallbacks; +static const ArchiveModuleCallbacks *ArchiveCallbacks; /* @@ -417,8 +417,8 @@ pgarch_ArchiverCopyLoop(void) HandlePgArchInterrupts(); /* can't do anything if not configured ... */ - if (ArchiveCallbacks.check_configured_cb != NULL && - !ArchiveCallbacks.check_configured_cb()) + if (ArchiveCallbacks->check_configured_cb != NULL && + !ArchiveCallbacks->check_configured_cb()) { ereport(WARNING, (errmsg("archive_mode enabled, yet archiving is not configured"))); @@ -519,7 +519,7 @@ pgarch_archiveXlog(char *xlog) snprintf(activitymsg, sizeof(activitymsg), "archiving %s", xlog); set_ps_display(activitymsg); - ret = ArchiveCallbacks.archive_file_cb(xlog, pathname); + ret = ArchiveCallbacks->archive_file_cb(xlog, pathname); if (ret) snprintf(activitymsg, sizeof(activitymsg), "last was %s", xlog); else @@ -838,8 +838,6 @@ LoadArchiveLibrary(void) errmsg("both archive_command and archive_library set"), errdetail("Only one of archive_command, archive_library may be set."))); - memset(&ArchiveCallbacks, 0, sizeof(ArchiveModuleCallbacks)); - /* * If shell archiving is enabled, use our special initialization function. * Otherwise, load the library and call its _PG_archive_module_init(). @@ -855,9 +853,9 @@ LoadArchiveLibrary(void) ereport(ERROR, (errmsg("archive modules have to define the symbol %s", "_PG_archive_module_init"))); - (*archive_init) (&ArchiveCallbacks); + ArchiveCallbacks = (*archive_init) (); - if (ArchiveCallbacks.archive_file_cb == NULL) + if (ArchiveCallbacks->archive_file_cb == NULL) ereport(ERROR, (errmsg("archive modules must register an archive callback"))); @@ -870,6 +868,6 @@ LoadArchiveLibrary(void) static void pgarch_call_module_shutdown_cb(int code, Datum arg) { - if (ArchiveCallbacks.shutdown_cb != NULL) - ArchiveCallbacks.shutdown_cb(); + if (ArchiveCallbacks->shutdown_cb != NULL) + ArchiveCallbacks->shutdown_cb(); } diff --git a/src/backend/postmaster/shell_archive.c b/src/backend/postmaster/shell_archive.c index b64297e3bb..dde20c83de 100644 --- a/src/backend/postmaster/shell_archive.c +++ b/src/backend/postmaster/shell_archive.c @@ -26,14 +26,18 @@ static bool shell_archive_configured(void); static bool shell_archive_file(const char *file, const char *path); static void shell_archive_shutdown(void); -void -shell_archive_init(ArchiveModuleCallbacks *cb) +static const ArchiveModuleCallbacks shell_archive_callbacks = { + .check_configured_cb = shell_archive_configured, + .archive_file_cb = shell_archive_file, + .shutdown_cb = shell_archive_shutdown +}; + +const ArchiveModuleCallbacks * +shell_archive_init(void) { AssertVariableIsOfType(&shell_archive_init, ArchiveModuleInit); - cb->check_configured_cb = shell_archive_configured; - cb->archive_file_cb = shell_archive_file; - cb->shutdown_cb = shell_archive_shutdown; + return &shell_archive_callbacks; } static bool diff --git a/src/include/postmaster/archive_module.h b/src/include/postmaster/archive_module.h index 099050c1ca..67b5624874 100644 --- a/src/include/postmaster/archive_module.h +++ b/src/include/postmaster/archive_module.h @@ -18,37 +18,31 @@ extern PGDLLIMPORT char *XLogArchiveLibrary; /* - * Archive module callbacks - * - * These callback functions should be defined by archive libraries and returned - * via _PG_archive_module_init(). ArchiveFileCB is the only required callback. - * For more information about the purpose of each callback, refer to the - * archive modules documentation. + * API struct for an archive module. This should be allocated as a static + * const struct and returned via _PG_archive_module_init. archive_file_cb is + * the only required callback. For more information about the purpose of each + * callback, refer to the archive modules documentation. */ -typedef bool (*ArchiveCheckConfiguredCB) (void); -typedef bool (*ArchiveFileCB) (const char *file, const char *path); -typedef void (*ArchiveShutdownCB) (void); - typedef struct ArchiveModuleCallbacks { - ArchiveCheckConfiguredCB check_configured_cb; - ArchiveFileCB archive_file_cb; - ArchiveShutdownCB shutdown_cb; + bool (*check_configured_cb) (void); + bool (*archive_file_cb) (const char *file, const char *path); + void (*shutdown_cb) (void); } ArchiveModuleCallbacks; /* * Type of the shared library symbol _PG_archive_module_init that is looked * up when loading an archive library. */ -typedef void (*ArchiveModuleInit) (ArchiveModuleCallbacks *cb); +typedef const ArchiveModuleCallbacks *(*ArchiveModuleInit) (void); -extern PGDLLEXPORT void _PG_archive_module_init(ArchiveModuleCallbacks *cb); +extern PGDLLEXPORT const ArchiveModuleCallbacks *_PG_archive_module_init(void); /* * Since the logic for archiving via a shell command is in the core server * and does not need to be loaded via a shared library, it has a special * initialization function. */ -extern void shell_archive_init(ArchiveModuleCallbacks *cb); +extern const ArchiveModuleCallbacks *shell_archive_init(void); #endif /* _ARCHIVE_MODULE_H */ -- 2.25.1