src/include/commands/copyto_internal.h

/*-------------------------------------------------------------------------
 *
 * copyto_internal.h
 *	  Internal definitions for COPY TO command.
 *
 *
 * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/commands/copyto_internal.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef COPYTO_INTERNAL_H
#define COPYTO_INTERNAL_H

#include "commands/copy.h"
#include "commands/copyfrom_internal.h"

typedef CopySource CopyDest;

/*
 * This struct contains all the state variables used throughout a COPY TO
 * operation.
 *
 * Multi-byte encodings: all supported client-side encodings encode multi-byte
 * characters by having the first byte's high bit set. Subsequent bytes of the
 * character can have the high bit not set. When scanning data in such an
 * encoding to look for a match to a single-byte (ie ASCII) character, we must
 * use the full pg_encoding_mblen() machinery to skip over multibyte
 * characters, else we might find a false match to a trailing byte. In
 * supported server encodings, there is no possibility of a false match, and
 * it's faster to make useless comparisons to trailing bytes than it is to
 * invoke pg_encoding_mblen() to skip over them. encoding_embeds_ascii is true
 * when we have to do it the hard way.
 */
typedef struct CopyToStateData
{
	/* low-level state data */
	CopyDest	copy_dest;		/* type of copy source/destination */
	FILE	   *copy_file;		/* used if copy_dest == COPY_FILE */
	StringInfo	fe_msgbuf;		/* used for all dests during COPY TO */

	int			file_encoding;	/* file or remote side's character encoding */
	bool		need_transcoding;	/* file encoding diff from server? */
	bool		encoding_embeds_ascii;	/* ASCII can be non-first byte? */

	/* parameters from the COPY command */
	Relation	rel;			/* relation to copy to */
	QueryDesc  *queryDesc;		/* executable query to copy from */
	List	   *attnumlist;		/* integer list of attnums to copy */
	List	   *attnamelist;    /* list of attributes by name */
	char	   *filename;		/* filename, or NULL for STDOUT */
	char	   *dirfilename;	/* filename of directory table, not NULL for copy directory table to */
	bool		is_program;		/* is 'filename' a program to popen? */
	copy_data_dest_cb data_dest_cb; /* function for writing data */

	CopyFormatOptions opts;
	Node	   *whereClause;	/* WHERE condition (or NULL) */

	/*
	 * Working state
	 */
	CopyDispatchMode dispatch_mode;
	MemoryContext copycontext;	/* per-copy execution context */

	FmgrInfo   *out_functions;	/* lookup info for output functions */
	MemoryContext rowcontext;	/* per-row evaluation context */
	uint64		bytes_processed;	/* number of bytes processed so far */

	/* Apache Cloudberry specific variables */
	Oid			conversion_proc;    /* encoding conversion function */
	FmgrInfo   *enc_conversion_proc;	  /* conv proc from exttbl encoding to
											 server or the other way around */
	bool		escape_off;     /* treat backslashes as non-special? */

	/* Information on the connections to QEs. */
	ProgramPipes    *program_pipes; /* COPY PROGRAM pipes for data and stderr */

	CdbCopy		*cdbCopy;
	/* end Apache Cloudberry specific variables */
} CopyToStateData;

#endif							/* COPYTO_INTERNAL_H */