logical.h

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/*-------------------------------------------------------------------------
 * logical.h
 *     PostgreSQL logical decoding coordination
 *
 * Copyright (c) 2012-2016, PostgreSQL Global Development Group
 *
 *-------------------------------------------------------------------------
 */
#ifndef LOGICAL_H
#define LOGICAL_H

#include "replication/slot.h"

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

struct LogicalDecodingContext;

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

typedef LogicalOutputPluginWriterWrite LogicalOutputPluginWriterPrepareWrite;

typedef struct LogicalDecodingContext
{
    /* memory context this is all allocated in */
    MemoryContext context;

    /* infrastructure pieces */
    XLogReaderState *reader;
    ReplicationSlot *slot;
    struct ReorderBuffer *reorder;
    struct SnapBuild *snapshot_builder;

    OutputPluginCallbacks callbacks;
    OutputPluginOptions options;

    /*
     * User specified options
     */
    List       *output_plugin_options;

    /*
     * User-Provided callback for writing/streaming out data.
     */
    LogicalOutputPluginWriterPrepareWrite prepare_write;
    LogicalOutputPluginWriterWrite write;

    /*
     * Output buffer.
     */
    StringInfo  out;

    /*
     * Private data pointer of the output plugin.
     */
    void       *output_plugin_private;

    /*
     * Private data pointer for the data writer.
     */
    void       *output_writer_private;

    /*
     * State for writing output.
     */
    bool        accept_writes;
    bool        prepared_write;
    XLogRecPtr  write_location;
    TransactionId write_xid;
} LogicalDecodingContext;

extern void CheckLogicalDecodingRequirements(void);

extern LogicalDecodingContext *CreateInitDecodingContext(char *plugin,
                          List *output_plugin_options,
                          XLogPageReadCB read_page,
                          LogicalOutputPluginWriterPrepareWrite prepare_write,
                          LogicalOutputPluginWriterWrite do_write);
extern LogicalDecodingContext *CreateDecodingContext(
                      XLogRecPtr start_lsn,
                      List *output_plugin_options,
                      XLogPageReadCB read_page,
                      LogicalOutputPluginWriterPrepareWrite prepare_write,
                      LogicalOutputPluginWriterWrite do_write);
extern void DecodingContextFindStartpoint(LogicalDecodingContext *ctx);
extern bool DecodingContextReady(LogicalDecodingContext *ctx);
extern void FreeDecodingContext(LogicalDecodingContext *ctx);

extern void LogicalIncreaseXminForSlot(XLogRecPtr lsn, TransactionId xmin);
extern void LogicalIncreaseRestartDecodingForSlot(XLogRecPtr current_lsn,
                                      XLogRecPtr restart_lsn);
extern void LogicalConfirmReceivedLocation(XLogRecPtr lsn);

extern bool filter_by_origin_cb_wrapper(LogicalDecodingContext *ctx, RepOriginId origin_id);

#endif