#include "access/xlog.h"
#include "access/xlogreader.h"
#include "replication/output_plugin.h"
#include "replication/slot.h"

Include dependency graph for logical.h:

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Data Structures
struct	LogicalDecodingContext

Typedefs
typedef void(*	LogicalOutputPluginWriterWrite) (struct LogicalDecodingContext *lr, XLogRecPtr Ptr, TransactionId xid, bool last_write)

typedef LogicalOutputPluginWriterWrite	LogicalOutputPluginWriterPrepareWrite

typedef void(*	LogicalOutputPluginWriterUpdateProgress) (struct LogicalDecodingContext *lr, XLogRecPtr Ptr, TransactionId xid)

typedef struct LogicalDecodingContext	LogicalDecodingContext

Functions
void	CheckLogicalDecodingRequirements (void)

LogicalDecodingContext *	CreateInitDecodingContext (char plugin, List output_plugin_options, bool need_full_snapshot, XLogRecPtr restart_lsn, XLogReaderRoutine *xl_routine, LogicalOutputPluginWriterPrepareWrite prepare_write, LogicalOutputPluginWriterWrite do_write, LogicalOutputPluginWriterUpdateProgress update_progress)

LogicalDecodingContext *	CreateDecodingContext (XLogRecPtr start_lsn, List output_plugin_options, bool fast_forward, XLogReaderRoutine xl_routine, LogicalOutputPluginWriterPrepareWrite prepare_write, LogicalOutputPluginWriterWrite do_write, LogicalOutputPluginWriterUpdateProgress update_progress)

void	DecodingContextFindStartpoint (LogicalDecodingContext *ctx)

bool	DecodingContextReady (LogicalDecodingContext *ctx)

void	FreeDecodingContext (LogicalDecodingContext *ctx)

void	LogicalIncreaseXminForSlot (XLogRecPtr lsn, TransactionId xmin)

void	LogicalIncreaseRestartDecodingForSlot (XLogRecPtr current_lsn, XLogRecPtr restart_lsn)

void	LogicalConfirmReceivedLocation (XLogRecPtr lsn)

bool	filter_by_origin_cb_wrapper (LogicalDecodingContext *ctx, RepOriginId origin_id)

Typedef Documentation

◆ LogicalDecodingContext

typedef struct LogicalDecodingContext LogicalDecodingContext

◆ LogicalOutputPluginWriterPrepareWrite

typedef LogicalOutputPluginWriterWrite LogicalOutputPluginWriterPrepareWrite

Definition at line 25 of file logical.h.

◆ LogicalOutputPluginWriterUpdateProgress

typedef void(* LogicalOutputPluginWriterUpdateProgress) (struct LogicalDecodingContext *lr, XLogRecPtr Ptr, TransactionId xid)

Definition at line 27 of file logical.h.

◆ LogicalOutputPluginWriterWrite

typedef void(* LogicalOutputPluginWriterWrite) (struct LogicalDecodingContext *lr, XLogRecPtr Ptr, TransactionId xid, bool last_write)

Definition at line 19 of file logical.h.

Function Documentation

◆ CheckLogicalDecodingRequirements()

void CheckLogicalDecodingRequirements ( void )

Definition at line 92 of file logical.c.

References CheckSlotRequirements(), ereport, errcode(), errmsg(), ERROR, InvalidOid, MyDatabaseId, RecoveryInProgress(), wal_level, and WAL_LEVEL_LOGICAL.

Referenced by copy_replication_slot(), CreateReplicationSlot(), pg_create_logical_replication_slot(), pg_logical_slot_get_changes_guts(), and StartLogicalReplication().

 {
     CheckSlotRequirements();
 
     /*
      * NB: Adding a new requirement likely means that RestoreSlotFromDisk()
      * needs the same check.
      */
 
     if (wal_level < WAL_LEVEL_LOGICAL)
         ereport(ERROR,
                 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
                  errmsg("logical decoding requires wal_level >= logical")));
 
     if (MyDatabaseId == InvalidOid)
         ereport(ERROR,
                 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
                  errmsg("logical decoding requires a database connection")));
 
     /* ----
      * TODO: We got to change that someday soon...
      *
      * There's basically three things missing to allow this:
      * 1) We need to be able to correctly and quickly identify the timeline a
      *    LSN belongs to
      * 2) We need to force hot_standby_feedback to be enabled at all times so
      *    the primary cannot remove rows we need.
      * 3) support dropping replication slots referring to a database, in
      *    dbase_redo. There can't be any active ones due to HS recovery
      *    conflicts, so that should be relatively easy.
      * ----
      */
     if (RecoveryInProgress())
         ereport(ERROR,
                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                  errmsg("logical decoding cannot be used while in recovery")));
 }

◆ CreateDecodingContext()

LogicalDecodingContext* CreateDecodingContext	(	XLogRecPtr	start_lsn,
		List *	output_plugin_options,
		bool	fast_forward,
		XLogReaderRoutine *	xl_routine,
		LogicalOutputPluginWriterPrepareWrite	prepare_write,
		LogicalOutputPluginWriterWrite	do_write,
		LogicalOutputPluginWriterUpdateProgress	update_progress
	)

Definition at line 426 of file logical.c.

References LogicalDecodingContext::callbacks, ReplicationSlotPersistentData::confirmed_flush, LogicalDecodingContext::context, LogicalErrorCallbackState::ctx, ReplicationSlot::data, ReplicationSlotPersistentData::database, DEBUG1, elog, ereport, errcode(), errdetail(), errmsg(), ERROR, InvalidTransactionId, InvalidXLogRecPtr, LOG, MemoryContextSwitchTo(), MyDatabaseId, MyReplicationSlot, ReplicationSlotPersistentData::name, NameStr, LogicalDecodingContext::options, ReorderBuffer::output_rewrites, OutputPluginOptions::receive_rewrites, LogicalDecodingContext::reorder, ReplicationSlotPersistentData::restart_lsn, SlotIsPhysical, OutputPluginCallbacks::startup_cb, startup_cb_wrapper(), and StartupDecodingContext().

Referenced by pg_logical_replication_slot_advance(), pg_logical_slot_get_changes_guts(), and StartLogicalReplication().

 {
     LogicalDecodingContext *ctx;
     ReplicationSlot *slot;
     MemoryContext old_context;
 
     /* shorter lines... */
     slot = MyReplicationSlot;
 
     /* first some sanity checks that are unlikely to be violated */
     if (slot == NULL)
         elog(ERROR, "cannot perform logical decoding without an acquired slot");
 
     /* make sure the passed slot is suitable, these are user facing errors */
     if (SlotIsPhysical(slot))
         ereport(ERROR,
                 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
                  errmsg("cannot use physical replication slot for logical decoding")));
 
     if (slot->data.database != MyDatabaseId)
         ereport(ERROR,
                 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
                  errmsg("replication slot \"%s\" was not created in this database",
                         NameStr(slot->data.name))));
 
     if (start_lsn == InvalidXLogRecPtr)
     {
         /* continue from last position */
         start_lsn = slot->data.confirmed_flush;
     }
     else if (start_lsn < slot->data.confirmed_flush)
     {
         /*
          * It might seem like we should error out in this case, but it's
          * pretty common for a client to acknowledge a LSN it doesn't have to
          * do anything for, and thus didn't store persistently, because the
          * xlog records didn't result in anything relevant for logical
          * decoding. Clients have to be able to do that to support synchronous
          * replication.
          */
         elog(DEBUG1, "cannot stream from %X/%X, minimum is %X/%X, forwarding",
              (uint32) (start_lsn >> 32), (uint32) start_lsn,
              (uint32) (slot->data.confirmed_flush >> 32),
              (uint32) slot->data.confirmed_flush);
 
         start_lsn = slot->data.confirmed_flush;
     }
 
     ctx = StartupDecodingContext(output_plugin_options,
                                  start_lsn, InvalidTransactionId, false,
                                  fast_forward, xl_routine, prepare_write,
                                  do_write, update_progress);
 
     /* call output plugin initialization callback */
     old_context = MemoryContextSwitchTo(ctx->context);
     if (ctx->callbacks.startup_cb != NULL)
         startup_cb_wrapper(ctx, &ctx->options, false);
     MemoryContextSwitchTo(old_context);
 
     ctx->reorder->output_rewrites = ctx->options.receive_rewrites;
 
     ereport(LOG,
             (errmsg("starting logical decoding for slot \"%s\"",
                     NameStr(slot->data.name)),
              errdetail("Streaming transactions committing after %X/%X, reading WAL from %X/%X.",
                        (uint32) (slot->data.confirmed_flush >> 32),
                        (uint32) slot->data.confirmed_flush,
                        (uint32) (slot->data.restart_lsn >> 32),
                        (uint32) slot->data.restart_lsn)));
 
     return ctx;
 }

◆ CreateInitDecodingContext()

LogicalDecodingContext* CreateInitDecodingContext	(	char *	plugin,
		List *	output_plugin_options,
		bool	need_full_snapshot,
		XLogRecPtr	restart_lsn,
		XLogReaderRoutine *	xl_routine,
		LogicalOutputPluginWriterPrepareWrite	prepare_write,
		LogicalOutputPluginWriterWrite	do_write,
		LogicalOutputPluginWriterUpdateProgress	update_progress
	)

Definition at line 280 of file logical.c.

References LogicalDecodingContext::callbacks, ReplicationSlotPersistentData::catalog_xmin, LogicalDecodingContext::context, LogicalErrorCallbackState::ctx, ReplicationSlot::data, ReplicationSlotPersistentData::database, ReplicationSlot::effective_catalog_xmin, ReplicationSlot::effective_xmin, elog, ereport, errcode(), errmsg(), ERROR, GetOldestSafeDecodingTransactionId(), GetTopTransactionIdIfAny(), InvalidTransactionId, IsTransactionState(), LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MemoryContextSwitchTo(), ReplicationSlot::mutex, MyDatabaseId, MyReplicationSlot, ReplicationSlotPersistentData::name, NAMEDATALEN, NameStr, NIL, LogicalDecodingContext::options, ReorderBuffer::output_rewrites, ReplicationSlotPersistentData::plugin, OutputPluginOptions::receive_rewrites, LogicalDecodingContext::reorder, ReplicationSlotMarkDirty(), ReplicationSlotReserveWal(), ReplicationSlotSave(), ReplicationSlotsComputeRequiredXmin(), ReplicationSlotPersistentData::restart_lsn, SlotIsPhysical, SpinLockAcquire, SpinLockRelease, OutputPluginCallbacks::startup_cb, startup_cb_wrapper(), StartupDecodingContext(), StrNCpy, and XLogRecPtrIsInvalid.

Referenced by create_logical_replication_slot(), and CreateReplicationSlot().

 {
     TransactionId xmin_horizon = InvalidTransactionId;
     ReplicationSlot *slot;
     LogicalDecodingContext *ctx;
     MemoryContext old_context;
 
     /* shorter lines... */
     slot = MyReplicationSlot;
 
     /* first some sanity checks that are unlikely to be violated */
     if (slot == NULL)
         elog(ERROR, "cannot perform logical decoding without an acquired slot");
 
     if (plugin == NULL)
         elog(ERROR, "cannot initialize logical decoding without a specified plugin");
 
     /* Make sure the passed slot is suitable. These are user facing errors. */
     if (SlotIsPhysical(slot))
         ereport(ERROR,
                 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
                  errmsg("cannot use physical replication slot for logical decoding")));
 
     if (slot->data.database != MyDatabaseId)
         ereport(ERROR,
                 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
                  errmsg("replication slot \"%s\" was not created in this database",
                         NameStr(slot->data.name))));
 
     if (IsTransactionState() &&
         GetTopTransactionIdIfAny() != InvalidTransactionId)
         ereport(ERROR,
                 (errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
                  errmsg("cannot create logical replication slot in transaction that has performed writes")));
 
     /* register output plugin name with slot */
     SpinLockAcquire(&slot->mutex);
     StrNCpy(NameStr(slot->data.plugin), plugin, NAMEDATALEN);
     SpinLockRelease(&slot->mutex);
 
     if (XLogRecPtrIsInvalid(restart_lsn))
         ReplicationSlotReserveWal();
     else
     {
         SpinLockAcquire(&slot->mutex);
         slot->data.restart_lsn = restart_lsn;
         SpinLockRelease(&slot->mutex);
     }
 
     /* ----
      * This is a bit tricky: We need to determine a safe xmin horizon to start
      * decoding from, to avoid starting from a running xacts record referring
      * to xids whose rows have been vacuumed or pruned
      * already. GetOldestSafeDecodingTransactionId() returns such a value, but
      * without further interlock its return value might immediately be out of
      * date.
      *
      * So we have to acquire the ProcArrayLock to prevent computation of new
      * xmin horizons by other backends, get the safe decoding xid, and inform
      * the slot machinery about the new limit. Once that's done the
      * ProcArrayLock can be released as the slot machinery now is
      * protecting against vacuum.
      *
      * Note that, temporarily, the data, not just the catalog, xmin has to be
      * reserved if a data snapshot is to be exported.  Otherwise the initial
      * data snapshot created here is not guaranteed to be valid. After that
      * the data xmin doesn't need to be managed anymore and the global xmin
      * should be recomputed. As we are fine with losing the pegged data xmin
      * after crash - no chance a snapshot would get exported anymore - we can
      * get away with just setting the slot's
      * effective_xmin. ReplicationSlotRelease will reset it again.
      *
      * ----
      */
     LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
 
     xmin_horizon = GetOldestSafeDecodingTransactionId(!need_full_snapshot);
 
     SpinLockAcquire(&slot->mutex);
     slot->effective_catalog_xmin = xmin_horizon;
     slot->data.catalog_xmin = xmin_horizon;
     if (need_full_snapshot)
         slot->effective_xmin = xmin_horizon;
     SpinLockRelease(&slot->mutex);
 
     ReplicationSlotsComputeRequiredXmin(true);
 
     LWLockRelease(ProcArrayLock);
 
     ReplicationSlotMarkDirty();
     ReplicationSlotSave();
 
     ctx = StartupDecodingContext(NIL, restart_lsn, xmin_horizon,
                                  need_full_snapshot, false,
                                  xl_routine, prepare_write, do_write,
                                  update_progress);
 
     /* call output plugin initialization callback */
     old_context = MemoryContextSwitchTo(ctx->context);
     if (ctx->callbacks.startup_cb != NULL)
         startup_cb_wrapper(ctx, &ctx->options, true);
     MemoryContextSwitchTo(old_context);
 
     ctx->reorder->output_rewrites = ctx->options.receive_rewrites;
 
     return ctx;
 }

◆ DecodingContextFindStartpoint()

void DecodingContextFindStartpoint ( LogicalDecodingContext * ctx )

Definition at line 518 of file logical.c.

References CHECK_FOR_INTERRUPTS, ReplicationSlotPersistentData::confirmed_flush, ReplicationSlot::data, DEBUG1, DecodingContextReady(), elog, XLogReaderState::EndRecPtr, ERROR, LogicalDecodingProcessRecord(), ReplicationSlot::mutex, LogicalDecodingContext::reader, ReplicationSlotPersistentData::restart_lsn, LogicalDecodingContext::slot, SpinLockAcquire, SpinLockRelease, XLogBeginRead(), and XLogReadRecord().

Referenced by create_logical_replication_slot(), and CreateReplicationSlot().

 {
     ReplicationSlot *slot = ctx->slot;
 
     /* Initialize from where to start reading WAL. */
     XLogBeginRead(ctx->reader, slot->data.restart_lsn);
 
     elog(DEBUG1, "searching for logical decoding starting point, starting at %X/%X",
          (uint32) (slot->data.restart_lsn >> 32),
          (uint32) slot->data.restart_lsn);
 
     /* Wait for a consistent starting point */
     for (;;)
     {
         XLogRecord *record;
         char       *err = NULL;
 
         /* the read_page callback waits for new WAL */
         record = XLogReadRecord(ctx->reader, &err);
         if (err)
             elog(ERROR, "%s", err);
         if (!record)
             elog(ERROR, "no record found"); /* shouldn't happen */
 
         LogicalDecodingProcessRecord(ctx, ctx->reader);
 
         /* only continue till we found a consistent spot */
         if (DecodingContextReady(ctx))
             break;
 
         CHECK_FOR_INTERRUPTS();
     }
 
     SpinLockAcquire(&slot->mutex);
     slot->data.confirmed_flush = ctx->reader->EndRecPtr;
     SpinLockRelease(&slot->mutex);
 }

◆ DecodingContextReady()

bool DecodingContextReady ( LogicalDecodingContext * ctx )

Definition at line 509 of file logical.c.

References SNAPBUILD_CONSISTENT, SnapBuildCurrentState(), and LogicalDecodingContext::snapshot_builder.

Referenced by DecodingContextFindStartpoint().

 {
     return SnapBuildCurrentState(ctx->snapshot_builder) == SNAPBUILD_CONSISTENT;
 }

◆ filter_by_origin_cb_wrapper()

bool filter_by_origin_cb_wrapper	(	LogicalDecodingContext *	ctx,
		RepOriginId	origin_id
	)

Definition at line 854 of file logical.c.

References LogicalDecodingContext::accept_writes, ErrorContextCallback::arg, Assert, ErrorContextCallback::callback, LogicalErrorCallbackState::callback_name, LogicalDecodingContext::callbacks, LogicalErrorCallbackState::ctx, error_context_stack, LogicalDecodingContext::fast_forward, OutputPluginCallbacks::filter_by_origin_cb, InvalidXLogRecPtr, output_plugin_error_callback(), ErrorContextCallback::previous, and LogicalErrorCallbackState::report_location.

Referenced by FilterByOrigin().

 {
     LogicalErrorCallbackState state;
     ErrorContextCallback errcallback;
     bool        ret;
 
     Assert(!ctx->fast_forward);
 
     /* Push callback + info on the error context stack */
     state.ctx = ctx;
     state.callback_name = "filter_by_origin";
     state.report_location = InvalidXLogRecPtr;
     errcallback.callback = output_plugin_error_callback;
     errcallback.arg = (void *) &state;
     errcallback.previous = error_context_stack;
     error_context_stack = &errcallback;
 
     /* set output state */
     ctx->accept_writes = false;
 
     /* do the actual work: call callback */
     ret = ctx->callbacks.filter_by_origin_cb(ctx, origin_id);
 
     /* Pop the error context stack */
     error_context_stack = errcallback.previous;
 
     return ret;
 }

◆ FreeDecodingContext()

void FreeDecodingContext ( LogicalDecodingContext * ctx )

Definition at line 561 of file logical.c.

References LogicalDecodingContext::callbacks, LogicalDecodingContext::context, FreeSnapshotBuilder(), MemoryContextDelete(), LogicalDecodingContext::reader, LogicalDecodingContext::reorder, ReorderBufferFree(), OutputPluginCallbacks::shutdown_cb, shutdown_cb_wrapper(), LogicalDecodingContext::snapshot_builder, and XLogReaderFree().

Referenced by create_logical_replication_slot(), CreateReplicationSlot(), pg_logical_replication_slot_advance(), pg_logical_slot_get_changes_guts(), and StartLogicalReplication().

 {
     if (ctx->callbacks.shutdown_cb != NULL)
         shutdown_cb_wrapper(ctx);
 
     ReorderBufferFree(ctx->reorder);
     FreeSnapshotBuilder(ctx->snapshot_builder);
     XLogReaderFree(ctx->reader);
     MemoryContextDelete(ctx->context);
 }

◆ LogicalConfirmReceivedLocation()

void LogicalConfirmReceivedLocation ( XLogRecPtr lsn )

Definition at line 1363 of file logical.c.

References Assert, ReplicationSlot::candidate_catalog_xmin, ReplicationSlot::candidate_restart_lsn, ReplicationSlot::candidate_restart_valid, ReplicationSlot::candidate_xmin_lsn, ReplicationSlotPersistentData::catalog_xmin, ReplicationSlotPersistentData::confirmed_flush, ReplicationSlot::data, DEBUG1, ReplicationSlot::effective_catalog_xmin, elog, InvalidTransactionId, InvalidXLogRecPtr, ReplicationSlot::mutex, MyReplicationSlot, ReplicationSlotMarkDirty(), ReplicationSlotSave(), ReplicationSlotsComputeRequiredLSN(), ReplicationSlotsComputeRequiredXmin(), ReplicationSlotPersistentData::restart_lsn, SpinLockAcquire, SpinLockRelease, and TransactionIdIsValid.

Referenced by LogicalIncreaseRestartDecodingForSlot(), LogicalIncreaseXminForSlot(), pg_logical_replication_slot_advance(), pg_logical_slot_get_changes_guts(), and ProcessStandbyReplyMessage().

 {
     Assert(lsn != InvalidXLogRecPtr);
 
     /* Do an unlocked check for candidate_lsn first. */
     if (MyReplicationSlot->candidate_xmin_lsn != InvalidXLogRecPtr ||
         MyReplicationSlot->candidate_restart_valid != InvalidXLogRecPtr)
     {
         bool        updated_xmin = false;
         bool        updated_restart = false;
 
         SpinLockAcquire(&MyReplicationSlot->mutex);
 
         MyReplicationSlot->data.confirmed_flush = lsn;
 
         /* if we're past the location required for bumping xmin, do so */
         if (MyReplicationSlot->candidate_xmin_lsn != InvalidXLogRecPtr &&
             MyReplicationSlot->candidate_xmin_lsn <= lsn)
         {
             /*
              * We have to write the changed xmin to disk *before* we change
              * the in-memory value, otherwise after a crash we wouldn't know
              * that some catalog tuples might have been removed already.
              *
              * Ensure that by first writing to ->xmin and only update
              * ->effective_xmin once the new state is synced to disk. After a
              * crash ->effective_xmin is set to ->xmin.
              */
             if (TransactionIdIsValid(MyReplicationSlot->candidate_catalog_xmin) &&
                 MyReplicationSlot->data.catalog_xmin != MyReplicationSlot->candidate_catalog_xmin)
             {
                 MyReplicationSlot->data.catalog_xmin = MyReplicationSlot->candidate_catalog_xmin;
                 MyReplicationSlot->candidate_catalog_xmin = InvalidTransactionId;
                 MyReplicationSlot->candidate_xmin_lsn = InvalidXLogRecPtr;
                 updated_xmin = true;
             }
         }
 
         if (MyReplicationSlot->candidate_restart_valid != InvalidXLogRecPtr &&
             MyReplicationSlot->candidate_restart_valid <= lsn)
         {
             Assert(MyReplicationSlot->candidate_restart_lsn != InvalidXLogRecPtr);
 
             MyReplicationSlot->data.restart_lsn = MyReplicationSlot->candidate_restart_lsn;
             MyReplicationSlot->candidate_restart_lsn = InvalidXLogRecPtr;
             MyReplicationSlot->candidate_restart_valid = InvalidXLogRecPtr;
             updated_restart = true;
         }
 
         SpinLockRelease(&MyReplicationSlot->mutex);
 
         /* first write new xmin to disk, so we know what's up after a crash */
         if (updated_xmin || updated_restart)
         {
             ReplicationSlotMarkDirty();
             ReplicationSlotSave();
             elog(DEBUG1, "updated xmin: %u restart: %u", updated_xmin, updated_restart);
         }
 
         /*
          * Now the new xmin is safely on disk, we can let the global value
          * advance. We do not take ProcArrayLock or similar since we only
          * advance xmin here and there's not much harm done by a concurrent
          * computation missing that.
          */
         if (updated_xmin)
         {
             SpinLockAcquire(&MyReplicationSlot->mutex);
             MyReplicationSlot->effective_catalog_xmin = MyReplicationSlot->data.catalog_xmin;
             SpinLockRelease(&MyReplicationSlot->mutex);
 
             ReplicationSlotsComputeRequiredXmin(false);
             ReplicationSlotsComputeRequiredLSN();
         }
     }
     else
     {
         SpinLockAcquire(&MyReplicationSlot->mutex);
         MyReplicationSlot->data.confirmed_flush = lsn;
         SpinLockRelease(&MyReplicationSlot->mutex);
     }
 }

◆ LogicalIncreaseRestartDecodingForSlot()

void LogicalIncreaseRestartDecodingForSlot	(	XLogRecPtr	current_lsn,
		XLogRecPtr	restart_lsn
	)

Definition at line 1286 of file logical.c.

References Assert, ReplicationSlot::candidate_restart_lsn, ReplicationSlot::candidate_restart_valid, ReplicationSlotPersistentData::confirmed_flush, ReplicationSlot::data, DEBUG1, elog, InvalidXLogRecPtr, LogicalConfirmReceivedLocation(), ReplicationSlot::mutex, MyReplicationSlot, SpinLockAcquire, and SpinLockRelease.

Referenced by SnapBuildProcessRunningXacts().

 {
     bool        updated_lsn = false;
     ReplicationSlot *slot;
 
     slot = MyReplicationSlot;
 
     Assert(slot != NULL);
     Assert(restart_lsn != InvalidXLogRecPtr);
     Assert(current_lsn != InvalidXLogRecPtr);
 
     SpinLockAcquire(&slot->mutex);
 
     /* don't overwrite if have a newer restart lsn */
     if (restart_lsn <= slot->data.restart_lsn)
     {
     }
 
     /*
      * We might have already flushed far enough to directly accept this lsn,
      * in this case there is no need to check for existing candidate LSNs
      */
     else if (current_lsn <= slot->data.confirmed_flush)
     {
         slot->candidate_restart_valid = current_lsn;
         slot->candidate_restart_lsn = restart_lsn;
 
         /* our candidate can directly be used */
         updated_lsn = true;
     }
 
     /*
      * Only increase if the previous values have been applied, otherwise we
      * might never end up updating if the receiver acks too slowly. A missed
      * value here will just cause some extra effort after reconnecting.
      */
     if (slot->candidate_restart_valid == InvalidXLogRecPtr)
     {
         slot->candidate_restart_valid = current_lsn;
         slot->candidate_restart_lsn = restart_lsn;
         SpinLockRelease(&slot->mutex);
 
         elog(DEBUG1, "got new restart lsn %X/%X at %X/%X",
              (uint32) (restart_lsn >> 32), (uint32) restart_lsn,
              (uint32) (current_lsn >> 32), (uint32) current_lsn);
     }
     else
     {
         XLogRecPtr  candidate_restart_lsn;
         XLogRecPtr  candidate_restart_valid;
         XLogRecPtr  confirmed_flush;
 
         candidate_restart_lsn = slot->candidate_restart_lsn;
         candidate_restart_valid = slot->candidate_restart_valid;
         confirmed_flush = slot->data.confirmed_flush;
         SpinLockRelease(&slot->mutex);
 
         elog(DEBUG1, "failed to increase restart lsn: proposed %X/%X, after %X/%X, current candidate %X/%X, current after %X/%X, flushed up to %X/%X",
              (uint32) (restart_lsn >> 32), (uint32) restart_lsn,
              (uint32) (current_lsn >> 32), (uint32) current_lsn,
              (uint32) (candidate_restart_lsn >> 32),
              (uint32) candidate_restart_lsn,
              (uint32) (candidate_restart_valid >> 32),
              (uint32) candidate_restart_valid,
              (uint32) (confirmed_flush >> 32),
              (uint32) confirmed_flush);
     }
 
     /* candidates are already valid with the current flush position, apply */
     if (updated_lsn)
         LogicalConfirmReceivedLocation(slot->data.confirmed_flush);
 }

◆ LogicalIncreaseXminForSlot()

void LogicalIncreaseXminForSlot	(	XLogRecPtr	lsn,
		TransactionId	xmin
	)

Definition at line 1229 of file logical.c.

References Assert, ReplicationSlot::candidate_catalog_xmin, ReplicationSlot::candidate_xmin_lsn, ReplicationSlotPersistentData::catalog_xmin, ReplicationSlotPersistentData::confirmed_flush, ReplicationSlot::data, InvalidXLogRecPtr, LogicalConfirmReceivedLocation(), ReplicationSlot::mutex, MyReplicationSlot, SpinLockAcquire, SpinLockRelease, and TransactionIdPrecedesOrEquals().