text: /*-------------------------------------------------------------------------
   *
   * copyfromparse.c
   *		Parse CSV/text/binary format for COPY FROM.
   *
   * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
   * Portions Copyright (c) 1994, Regents of the University of California
   *
   *
   * IDENTIFICATION
   *	  src/backend/commands/copyfromparse.c
   *
   *-------------------------------------------------------------------------
   */
  #include "postgres.h"
  
  #include <ctype.h>
  #include <unistd.h>
  #include <sys/stat.h>
  
  #include "commands/copy.h"
  #include "commands/copyfrom_internal.h"
  #include "executor/executor.h"
  #include "libpq/libpq.h"
  #include "libpq/pqformat.h"
  #include "mb/pg_wchar.h"
  #include "miscadmin.h"
  #include "port/pg_bswap.h"
  #include "utils/memutils.h"
  #include "utils/rel.h"
  
  #define ISOCTAL(c) (((c) >= '0') && ((c) <= '7'))
  #define OCTVALUE(c) ((c) - '0')
  
  /*
   * These macros centralize code used to process line_buf and raw_buf buffers.
   * They are macros because they often do continue/break control and to avoid
   * function call overhead in tight COPY loops.
   *
   * We must use "if (1)" because the usual "do {...} while(0)" wrapper would
   * prevent the continue/break processing from working.  We end the "if (1)"
   * with "else ((void) 0)" to ensure the "if" does not unintentionally match
   * any "else" in the calling code, and to avoid any compiler warnings about
   * empty statements.  See http://www.cit.gu.edu.au/~anthony/info/C/C.macros.
   */
  
  /*
   * This keeps the character read at the top of the loop in the buffer
   * even if there is more than one read-ahead.
   */
  #define IF_NEED_REFILL_AND_NOT_EOF_CONTINUE(extralen) \
  if (1) \
  { \
  	if (raw_buf_ptr + (extralen) >= copy_buf_len && !hit_eof) \
  	{ \
  		raw_buf_ptr = prev_raw_ptr; /* undo fetch */ \
  		need_data = true; \
  		continue; \
  	} \
  } else ((void) 0)
  
  /* This consumes the remainder of the buffer and breaks */
  #define IF_NEED_REFILL_AND_EOF_BREAK(extralen) \
  if (1) \
  { \
  	if (raw_buf_ptr + (extralen) >= copy_buf_len && hit_eof) \
  	{ \
  		if (extralen) \
  			raw_buf_ptr = copy_buf_len; /* consume the partial character */ \
  		/* backslash just before EOF, treat as data char */ \
  		result = true; \
  		break; \
  	} \
  } else ((void) 0)
  
  /*
   * Transfer any approved data to line_buf; must do this to be sure
   * there is some room in raw_buf.
   */
  #define REFILL_LINEBUF \
  if (1) \
  { \
  	if (raw_buf_ptr > cstate->raw_buf_index) \
  	{ \
  		appendBinaryStringInfo(&cstate->line_buf, \
  							 cstate->raw_buf + cstate->raw_buf_index, \
  							   raw_buf_ptr - cstate->raw_buf_index); \
  		cstate->raw_buf_index = raw_buf_ptr; \
  	} \
  } else ((void) 0)
  
  /* Undo any read-ahead and jump out of the block. */
  #define NO_END_OF_COPY_GOTO \
  if (1) \
  { \
  	raw_buf_ptr = prev_raw_ptr + 1; \
  	goto not_end_of_copy; \
  } else ((void) 0)
  
  /* NOTE: there's a copy of this in copyto.c */
  static const char BinarySignature[11] = "PGCOPY\n\377\r\n\0";
  
  
  /* non-export function prototypes */
  static bool CopyReadLine(CopyFromState cstate);
  static bool CopyReadLineText(CopyFromState cstate);
  static int	CopyReadAttributesText(CopyFromState cstate);
  static int	CopyReadAttributesCSV(CopyFromState cstate);
  static Datum CopyReadBinaryAttribute(CopyFromState cstate, FmgrInfo *flinfo,
  									 Oid typioparam, int32 typmod,
  									 bool *isnull);
  
  
  /* Low-level communications functions */
  static int	CopyGetData(CopyFromState cstate, void *databuf,
  						int minread, int maxread);
  static inline bool CopyGetInt32(CopyFromState cstate, int32 *val);
  static inline bool CopyGetInt16(CopyFromState cstate, int16 *val);
  static bool CopyLoadRawBuf(CopyFromState cstate);
  static int	CopyReadBinaryData(CopyFromState cstate, char *dest, int nbytes);
  
  void
  ReceiveCopyBegin(CopyFromState cstate)
  {
  	if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 3)
  	{
  		/* new way */
  		StringInfoData buf;
  		int			natts = list_length(cstate->attnumlist);
  		int16		format = (cstate->opts.binary ? 1 : 0);
  		int			i;
  
  		pq_beginmessage(&buf, 'G');
  		pq_sendbyte(&buf, format);	/* overall format */
  		pq_sendint16(&buf, natts);
  		for (i = 0; i < natts; i++)
  			pq_sendint16(&buf, format); /* per-column formats */
  		pq_endmessage(&buf);
  		cstate->copy_src = COPY_NEW_FE;
  		cstate->fe_msgbuf = makeStringInfo();
  	}
  	else
  	{
  		/* old way */
  		if (cstate->opts.binary)
  			ereport(ERROR,
  					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
  					 errmsg("COPY BINARY is not supported to stdout or from stdin")));
  		pq_putemptymessage('G');
  		/* any error in old protocol will make us lose sync */
  		pq_startmsgread();
  		cstate->copy_src = COPY_OLD_FE;
  	}
  	/* We *must* flush here to ensure FE knows it can send. */
  	pq_flush();
  }
  
  void
  ReceiveCopyBinaryHeader(CopyFromState cstate)
  {
  	char		readSig[11];
  	int32		tmp;
  
  	/* Signature */
  	if (CopyReadBinaryData(cstate, readSig, 11) != 11 ||
  		memcmp(readSig, BinarySignature, 11) != 0)
  		ereport(ERROR,
  				(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  				 errmsg("COPY file signature not recognized")));
  	/* Flags field */
  	if (!CopyGetInt32(cstate, &tmp))
  		ereport(ERROR,
  				(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  				 errmsg("invalid COPY file header (missing flags)")));
  	if ((tmp & (1 << 16)) != 0)
  		ereport(ERROR,
  				(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  				 errmsg("invalid COPY file header (WITH OIDS)")));
  	tmp &= ~(1 << 16);
  	if ((tmp >> 16) != 0)
  		ereport(ERROR,
  				(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  				 errmsg("unrecognized critical flags in COPY file header")));
  	/* Header extension length */
  	if (!CopyGetInt32(cstate, &tmp) ||
  		tmp < 0)
  		ereport(ERROR,
  				(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  				 errmsg("invalid COPY file header (missing length)")));
  	/* Skip extension header, if present */
  	while (tmp-- > 0)
  	{
  		if (CopyReadBinaryData(cstate, readSig, 1) != 1)
  			ereport(ERROR,
  					(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  					 errmsg("invalid COPY file header (wrong length)")));
  	}
  }
  
  /*
   * CopyGetData reads data from the source (file or frontend)
   *
   * We attempt to read at least minread, and at most maxread, bytes from
   * the source.  The actual number of bytes read is returned; if this is
   * less than minread, EOF was detected.
   *
   * Note: when copying from the frontend, we expect a proper EOF mark per
   * protocol; if the frontend simply drops the connection, we raise error.
   * It seems unwise to allow the COPY IN to complete normally in that case.
   *
   * NB: no data conversion is applied here.
   */
  static int
  CopyGetData(CopyFromState cstate, void *databuf, int minread, int maxread)
  {
  	int			bytesread = 0;
  
  	switch (cstate->copy_src)
  	{
  		case COPY_FILE:
  			bytesread = fread(databuf, 1, maxread, cstate->copy_file);
  			if (ferror(cstate->copy_file))
  				ereport(ERROR,
  						(errcode_for_file_access(),
  						 errmsg("could not read from COPY file: %m")));
  			if (bytesread == 0)
  				cstate->reached_eof = true;
  			break;
  		case COPY_OLD_FE:
  
  			/*
  			 * We cannot read more than minread bytes (which in practice is 1)
  			 * because old protocol doesn't have any clear way of separating
  			 * the COPY stream from following data.  This is slow, but not any
  			 * slower than the code path was originally, and we don't care
  			 * much anymore about the performance of old protocol.
  			 */
  			if (pq_getbytes((char *) databuf, minread))
  			{
  				/* Only a \. terminator is legal EOF in old protocol */
  				ereport(ERROR,
  						(errcode(ERRCODE_CONNECTION_FAILURE),
  						 errmsg("unexpected EOF on client connection with an open transaction")));
  			}
  			bytesread = minread;
  			break;
  		case COPY_NEW_FE:
  			while (maxread > 0 && bytesread < minread && !cstate->reached_eof)
  			{
  				int			avail;
  
  				while (cstate->fe_msgbuf->cursor >= cstate->fe_msgbuf->len)
  				{
  					/* Try to receive another message */
  					int			mtype;
  
  			readmessage:
  					HOLD_CANCEL_INTERRUPTS();
  					pq_startmsgread();
  					mtype = pq_getbyte();
  					if (mtype == EOF)
  						ereport(ERROR,
  								(errcode(ERRCODE_CONNECTION_FAILURE),
  								 errmsg("unexpected EOF on client connection with an open transaction")));
  					if (pq_getmessage(cstate->fe_msgbuf, 0))
  						ereport(ERROR,
  								(errcode(ERRCODE_CONNECTION_FAILURE),
  								 errmsg("unexpected EOF on client connection with an open transaction")));
  					RESUME_CANCEL_INTERRUPTS();
  					switch (mtype)
  					{
  						case 'd':	/* CopyData */
  							break;
  						case 'c':	/* CopyDone */
  							/* COPY IN correctly terminated by frontend */
  							cstate->reached_eof = true;
  							return bytesread;
  						case 'f':	/* CopyFail */
  							ereport(ERROR,
  									(errcode(ERRCODE_QUERY_CANCELED),
  									 errmsg("COPY from stdin failed: %s",
  											pq_getmsgstring(cstate->fe_msgbuf))));
  							break;
  						case 'H':	/* Flush */
  						case 'S':	/* Sync */
  
  							/*
  							 * Ignore Flush/Sync for the convenience of client
  							 * libraries (such as libpq) that may send those
  							 * without noticing that the command they just
  							 * sent was COPY.
  							 */
  							goto readmessage;
  						default:
  							ereport(ERROR,
  									(errcode(ERRCODE_PROTOCOL_VIOLATION),
  									 errmsg("unexpected message type 0x%02X during COPY from stdin",
  											mtype)));
  							break;
  					}
  				}
  				avail = cstate->fe_msgbuf->len - cstate->fe_msgbuf->cursor;
  				if (avail > maxread)
  					avail = maxread;
  				pq_copymsgbytes(cstate->fe_msgbuf, databuf, avail);
  				databuf = (void *) ((char *) databuf + avail);
  				maxread -= avail;
  				bytesread += avail;
  			}
  			break;
  		case COPY_CALLBACK:
  			bytesread = cstate->data_source_cb(databuf, minread, maxread);
  			break;
  	}
  
  	return bytesread;
  }
  
  
  /*
   * These functions do apply some data conversion
   */
  
  /*
   * CopyGetInt32 reads an int32 that appears in network byte order
   *
   * Returns true if OK, false if EOF
   */
  static inline bool
  CopyGetInt32(CopyFromState cstate, int32 *val)
  {
  	uint32		buf;
  
  	if (CopyReadBinaryData(cstate, (char *) &buf, sizeof(buf)) != sizeof(buf))
  	{
  		*val = 0;				/* suppress compiler warning */
  		return false;
  	}
  	*val = (int32) pg_ntoh32(buf);
  	return true;
  }
  
  /*
   * CopyGetInt16 reads an int16 that appears in network byte order
   */
  static inline bool
  CopyGetInt16(CopyFromState cstate, int16 *val)
  {
  	uint16		buf;
  
  	if (CopyReadBinaryData(cstate, (char *) &buf, sizeof(buf)) != sizeof(buf))
  	{
  		*val = 0;				/* suppress compiler warning */
  		return false;
  	}
  	*val = (int16) pg_ntoh16(buf);
  	return true;
  }
  
  
  /*
   * CopyLoadRawBuf loads some more data into raw_buf
   *
   * Returns true if able to obtain at least one more byte, else false.
   *
   * If RAW_BUF_BYTES(cstate) > 0, the unprocessed bytes are moved to the start
   * of the buffer and then we load more data after that.  This case occurs only
   * when a multibyte character crosses a bufferload boundary.
   */
  static bool
  CopyLoadRawBuf(CopyFromState cstate)
  {
  	int			nbytes = RAW_BUF_BYTES(cstate);
  	int			inbytes;
  
  	/* Copy down the unprocessed data if any. */
  	if (nbytes > 0)
  		memmove(cstate->raw_buf, cstate->raw_buf + cstate->raw_buf_index,
  				nbytes);
  
  	inbytes = CopyGetData(cstate, cstate->raw_buf + nbytes,
  						  1, RAW_BUF_SIZE - nbytes);
  	nbytes += inbytes;
  	cstate->raw_buf[nbytes] = '\0';
  	cstate->raw_buf_index = 0;
  	cstate->raw_buf_len = nbytes;
  	return (inbytes > 0);
  }
  
  /*
   * CopyReadBinaryData
   *
   * Reads up to 'nbytes' bytes from cstate->copy_file via cstate->raw_buf
   * and writes them to 'dest'.  Returns the number of bytes read (which
   * would be less than 'nbytes' only if we reach EOF).
   */
  static int
  CopyReadBinaryData(CopyFromState cstate, char *dest, int nbytes)
  {
  	int			copied_bytes = 0;
  
  	if (RAW_BUF_BYTES(cstate) >= nbytes)
  	{
  		/* Enough bytes are present in the buffer. */
  		memcpy(dest, cstate->raw_buf + cstate->raw_buf_index, nbytes);
  		cstate->raw_buf_index += nbytes;
  		copied_bytes = nbytes;
  	}
  	else
  	{
  		/*
  		 * Not enough bytes in the buffer, so must read from the file.  Need
  		 * to loop since 'nbytes' could be larger than the buffer size.
  		 */
  		do
  		{
  			int			copy_bytes;
  
  			/* Load more data if buffer is empty. */
  			if (RAW_BUF_BYTES(cstate) == 0)
  			{
  				if (!CopyLoadRawBuf(cstate))
  					break;		/* EOF */
  			}
  
  			/* Transfer some bytes. */
  			copy_bytes = Min(nbytes - copied_bytes, RAW_BUF_BYTES(cstate));
  			memcpy(dest, cstate->raw_buf + cstate->raw_buf_index, copy_bytes);
  			cstate->raw_buf_index += copy_bytes;
  			dest += copy_bytes;
  			copied_bytes += copy_bytes;
  		} while (copied_bytes < nbytes);
  	}
  
  	return copied_bytes;
  }
  
  /*
   * Read raw fields in the next line for COPY FROM in text or csv mode.
   * Return false if no more lines.
   *
   * An internal temporary buffer is returned via 'fields'. It is valid until
   * the next call of the function. Since the function returns all raw fields
   * in the input file, 'nfields' could be different from the number of columns
   * in the relation.
   *
   * NOTE: force_not_null option are not applied to the returned fields.
   */
  bool
  NextCopyFromRawFields(CopyFromState cstate, char ***fields, int *nfields)
  {
  	int			fldct;
  	bool		done;
  
  	/* only available for text or csv input */
  	Assert(!cstate->opts.binary);
  
  	/* on input just throw the header line away */
  	if (cstate->cur_lineno == 0 && cstate->opts.header_line)
  	{
  		cstate->cur_lineno++;
  		if (CopyReadLine(cstate))
  			return false;		/* done */
  	}
  
  	cstate->cur_lineno++;
  
  	/* Actually read the line into memory here */
  	done = CopyReadLine(cstate);
  
  	/*
  	 * EOF at start of line means we're done.  If we see EOF after some
  	 * characters, we act as though it was newline followed by EOF, ie,
  	 * process the line and then exit loop on next iteration.
  	 */
  	if (done && cstate->line_buf.len == 0)
  		return false;
  
  	/* Parse the line into de-escaped field values */
  	if (cstate->opts.csv_mode)
  		fldct = CopyReadAttributesCSV(cstate);
  	else
  		fldct = CopyReadAttributesText(cstate);
  
  	*fields = cstate->raw_fields;
  	*nfields = fldct;
  	return true;
  }
  
  /*
   * Read next tuple from file for COPY FROM. Return false if no more tuples.
   *
   * 'econtext' is used to evaluate default expression for each columns not
   * read from the file. It can be NULL when no default values are used, i.e.
   * when all columns are read from the file.
   *
   * 'values' and 'nulls' arrays must be the same length as columns of the
   * relation passed to BeginCopyFrom. This function fills the arrays.
   * Oid of the tuple is returned with 'tupleOid' separately.
   */
  bool
  NextCopyFrom(CopyFromState cstate, ExprContext *econtext,
  			 Datum *values, bool *nulls)
  {
  	TupleDesc	tupDesc;
  	AttrNumber	num_phys_attrs,
  				attr_count,
  				num_defaults = cstate->num_defaults;
  	FmgrInfo   *in_functions = cstate->in_functions;
  	Oid		   *typioparams = cstate->typioparams;
  	int			i;
  	int		   *defmap = cstate->defmap;
  	ExprState **defexprs = cstate->defexprs;
  
  	tupDesc = RelationGetDescr(cstate->rel);
  	num_phys_attrs = tupDesc->natts;
  	attr_count = list_length(cstate->attnumlist);
  
  	/* Initialize all values for row to NULL */
  	MemSet(values, 0, num_phys_attrs * sizeof(Datum));
  	MemSet(nulls, true, num_phys_attrs * sizeof(bool));
  
  	if (!cstate->opts.binary)
  	{
  		char	  **field_strings;
  		ListCell   *cur;
  		int			fldct;
  		int			fieldno;
  		char	   *string;
  
  		/* read raw fields in the next line */
  		if (!NextCopyFromRawFields(cstate, &field_strings, &fldct))
  			return false;
  
  		/* check for overflowing fields */
  		if (attr_count > 0 && fldct > attr_count)
  			ereport(ERROR,
  					(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  					 errmsg("extra data after last expected column")));
  
  		fieldno = 0;
  
  		/* Loop to read the user attributes on the line. */
  		foreach(cur, cstate->attnumlist)
  		{
  			int			attnum = lfirst_int(cur);
  			int			m = attnum - 1;
  			Form_pg_attribute att = TupleDescAttr(tupDesc, m);
  
  			if (fieldno >= fldct)
  				ereport(ERROR,
  						(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  						 errmsg("missing data for column \"%s\"",
  								NameStr(att->attname))));
  			string = field_strings[fieldno++];
  
  			if (cstate->convert_select_flags &&
  				!cstate->convert_select_flags[m])
  			{
  				/* ignore input field, leaving column as NULL */
  				continue;
  			}
  
  			if (cstate->opts.csv_mode)
  			{
  				if (string == NULL &&
  					cstate->opts.force_notnull_flags[m])
  				{
  					/*
  					 * FORCE_NOT_NULL option is set and column is NULL -
  					 * convert it to the NULL string.
  					 */
  					string = cstate->opts.null_print;
  				}
  				else if (string != NULL && cstate->opts.force_null_flags[m]
  						 && strcmp(string, cstate->opts.null_print) == 0)
  				{
  					/*
  					 * FORCE_NULL option is set and column matches the NULL
  					 * string. It must have been quoted, or otherwise the
  					 * string would already have been set to NULL. Convert it
  					 * to NULL as specified.
  					 */
  					string = NULL;
  				}
  			}
  
  			cstate->cur_attname = NameStr(att->attname);
  			cstate->cur_attval = string;
  			values[m] = InputFunctionCall(&in_functions[m],
  										  string,
  										  typioparams[m],
  										  att->atttypmod);
  			if (string != NULL)
  				nulls[m] = false;
  			cstate->cur_attname = NULL;
  			cstate->cur_attval = NULL;
  		}
  
  		Assert(fieldno == attr_count);
  	}
  	else
  	{
  		/* binary */
  		int16		fld_count;
  		ListCell   *cur;
  
  		cstate->cur_lineno++;
  
  		if (!CopyGetInt16(cstate, &fld_count))
  		{
  			/* EOF detected (end of file, or protocol-level EOF) */
  			return false;
  		}
  
  		if (fld_count == -1)
  		{
  			/*
  			 * Received EOF marker.  In a V3-protocol copy, wait for the
  			 * protocol-level EOF, and complain if it doesn't come
  			 * immediately.  This ensures that we correctly handle CopyFail,
  			 * if client chooses to send that now.
  			 *
  			 * Note that we MUST NOT try to read more data in an old-protocol
  			 * copy, since there is no protocol-level EOF marker then.  We
  			 * could go either way for copy from file, but choose to throw
  			 * error if there's data after the EOF marker, for consistency
  			 * with the new-protocol case.
  			 */
  			char		dummy;
  
  			if (cstate->copy_src != COPY_OLD_FE &&
  				CopyReadBinaryData(cstate, &dummy, 1) > 0)
  				ereport(ERROR,
  						(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  						 errmsg("received copy data after EOF marker")));
  			return false;
  		}
  
  		if (fld_count != attr_count)
  			ereport(ERROR,
  					(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  					 errmsg("row field count is %d, expected %d",
  							(int) fld_count, attr_count)));
  
  		foreach(cur, cstate->attnumlist)
  		{
  			int			attnum = lfirst_int(cur);
  			int			m = attnum - 1;
  			Form_pg_attribute att = TupleDescAttr(tupDesc, m);
  
  			cstate->cur_attname = NameStr(att->attname);
  			values[m] = CopyReadBinaryAttribute(cstate,
  												&in_functions[m],
  												typioparams[m],
  												att->atttypmod,
  												&nulls[m]);
  			cstate->cur_attname = NULL;
  		}
  	}
  
  	/*
  	 * Now compute and insert any defaults available for the columns not
  	 * provided by the input data.  Anything not processed here or above will
  	 * remain NULL.
  	 */
  	for (i = 0; i < num_defaults; i++)
  	{
  		/*
  		 * The caller must supply econtext and have switched into the
  		 * per-tuple memory context in it.
  		 */
  		Assert(econtext != NULL);
  		Assert(CurrentMemoryContext == econtext->ecxt_per_tuple_memory);
  
  		values[defmap[i]] = ExecEvalExpr(defexprs[i], econtext,
  										 &nulls[defmap[i]]);
  	}
  
  	return true;
  }
  
  /*
   * Read the next input line and stash it in line_buf, with conversion to
   * server encoding.
   *
   * Result is true if read was terminated by EOF, false if terminated
   * by newline.  The terminating newline or EOF marker is not included
   * in the final value of line_buf.
   */
  static bool
  CopyReadLine(CopyFromState cstate)
  {
  	bool		result;
  
  	resetStringInfo(&cstate->line_buf);
  	cstate->line_buf_valid = true;
  
  	/* Mark that encoding conversion hasn't occurred yet */
  	cstate->line_buf_converted = false;
  
  	/* Parse data and transfer into line_buf */
  	result = CopyReadLineText(cstate);
  
  	if (result)
  	{
  		/*
  		 * Reached EOF.  In protocol version 3, we should ignore anything
  		 * after \. up to the protocol end of copy data.  (XXX maybe better
  		 * not to treat \. as special?)
  		 */
  		if (cstate->copy_src == COPY_NEW_FE)
  		{
  			do
  			{
  				cstate->raw_buf_index = cstate->raw_buf_len;
  			} while (CopyLoadRawBuf(cstate));
  		}
  	}
  	else
  	{
  		/*
  		 * If we didn't hit EOF, then we must have transferred the EOL marker
  		 * to line_buf along with the data.  Get rid of it.
  		 */
  		switch (cstate->eol_type)
  		{
  			case EOL_NL:
  				Assert(cstate->line_buf.len >= 1);
  				Assert(cstate->line_buf.data[cstate->line_buf.len - 1] == '\n');
  				cstate->line_buf.len--;
  				cstate->line_buf.data[cstate->line_buf.len] = '\0';
  				break;
  			case EOL_CR:
  				Assert(cstate->line_buf.len >= 1);
  				Assert(cstate->line_buf.data[cstate->line_buf.len - 1] == '\r');
  				cstate->line_buf.len--;
  				cstate->line_buf.data[cstate->line_buf.len] = '\0';
  				break;
  			case EOL_CRNL:
  				Assert(cstate->line_buf.len >= 2);
  				Assert(cstate->line_buf.data[cstate->line_buf.len - 2] == '\r');
  				Assert(cstate->line_buf.data[cstate->line_buf.len - 1] == '\n');
  				cstate->line_buf.len -= 2;
  				cstate->line_buf.data[cstate->line_buf.len] = '\0';
  				break;
  			case EOL_UNKNOWN:
  				/* shouldn't get here */
  				Assert(false);
  				break;
  		}
  	}
  
  	/* Done reading the line.  Convert it to server encoding. */
  	if (cstate->need_transcoding)
  	{
  		char	   *cvt;
  
  		cvt = pg_any_to_server(cstate->line_buf.data,
  							   cstate->line_buf.len,
  							   cstate->file_encoding);
  		if (cvt != cstate->line_buf.data)
  		{
  			/* transfer converted data back to line_buf */
  			resetStringInfo(&cstate->line_buf);
  			appendBinaryStringInfo(&cstate->line_buf, cvt, strlen(cvt));
  			pfree(cvt);
  		}
  	}
  
  	/* Now it's safe to use the buffer in error messages */
  	cstate->line_buf_converted = true;
  
  	return result;
  }
  
  /*
   * CopyReadLineText - inner loop of CopyReadLine for text mode
   */
  static bool
  CopyReadLineText(CopyFromState cstate)
  {
  	char	   *copy_raw_buf;
  	int			raw_buf_ptr;
  	int			copy_buf_len;
  	bool		need_data = false;
  	bool		hit_eof = false;
  	bool		result = false;
  	char		mblen_str[2];
  
  	/* CSV variables */
  	bool		first_char_in_line = true;
  	bool		in_quote = false,
  				last_was_esc = false;
  	char		quotec = '\0';
  	char		escapec = '\0';
  
  	if (cstate->opts.csv_mode)
  	{
  		quotec = cstate->opts.quote[0];
  		escapec = cstate->opts.escape[0];
  		/* ignore special escape processing if it's the same as quotec */
  		if (quotec == escapec)
  			escapec = '\0';
  	}
  
  	mblen_str[1] = '\0';
  
  	/*
  	 * The objective of this loop is to transfer the entire next input line
  	 * into line_buf.  Hence, we only care for detecting newlines (\r and/or
  	 * \n) and the end-of-copy marker (\.).
  	 *
  	 * In CSV mode, \r and \n inside a quoted field are just part of the data
  	 * value and are put in line_buf.  We keep just enough state to know if we
  	 * are currently in a quoted field or not.
  	 *
  	 * These four characters, and the CSV escape and quote characters, are
  	 * assumed the same in frontend and backend encodings.
  	 *
  	 * For speed, we try to move data from raw_buf to line_buf in chunks
  	 * rather than one character at a time.  raw_buf_ptr points to the next
  	 * character to examine; any characters from raw_buf_index to raw_buf_ptr
  	 * have been determined to be part of the line, but not yet transferred to
  	 * line_buf.
  	 *
  	 * For a little extra speed within the loop, we copy raw_buf and
  	 * raw_buf_len into local variables.
  	 */
  	copy_raw_buf = cstate->raw_buf;
  	raw_buf_ptr = cstate->raw_buf_index;
  	copy_buf_len = cstate->raw_buf_len;
  
  	for (;;)
  	{
  		int			prev_raw_ptr;
  		char		c;
  
  		/*
  		 * Load more data if needed.  Ideally we would just force four bytes
  		 * of read-ahead and avoid the many calls to
  		 * IF_NEED_REFILL_AND_NOT_EOF_CONTINUE(), but the COPY_OLD_FE protocol
  		 * does not allow us to read too far ahead or we might read into the
  		 * next data, so we read-ahead only as far we know we can.  One
  		 * optimization would be to read-ahead four byte here if
  		 * cstate->copy_src != COPY_OLD_FE, but it hardly seems worth it,
  		 * considering the size of the buffer.
  		 */
  		if (raw_buf_ptr >= copy_buf_len || need_data)
  		{
  			REFILL_LINEBUF;
  
  			/*
  			 * Try to read some more data.  This will certainly reset
  			 * raw_buf_index to zero, and raw_buf_ptr must go with it.
  			 */
  			if (!CopyLoadRawBuf(cstate))
  				hit_eof = true;
  			raw_buf_ptr = 0;
  			copy_buf_len = cstate->raw_buf_len;
  
  			/*
  			 * If we are completely out of data, break out of the loop,
  			 * reporting EOF.
  			 */
  			if (copy_buf_len <= 0)
  			{
  				result = true;
  				break;
  			}
  			need_data = false;
  		}
  
  		/* OK to fetch a character */
  		prev_raw_ptr = raw_buf_ptr;
  		c = copy_raw_buf[raw_buf_ptr++];
  
  		if (cstate->opts.csv_mode)
  		{
  			/*
  			 * If character is '\\' or '\r', we may need to look ahead below.
  			 * Force fetch of the next character if we don't already have it.
  			 * We need to do this before changing CSV state, in case one of
  			 * these characters is also the quote or escape character.
  			 *
  			 * Note: old-protocol does not like forced prefetch, but it's OK
  			 * here since we cannot validly be at EOF.
  			 */
  			if (c == '\\' || c == '\r')
  			{
  				IF_NEED_REFILL_AND_NOT_EOF_CONTINUE(0);
  			}
  
  			/*
  			 * Dealing with quotes and escapes here is mildly tricky. If the
  			 * quote char is also the escape char, there's no problem - we
  			 * just use the char as a toggle. If they are different, we need
  			 * to ensure that we only take account of an escape inside a
  			 * quoted field and immediately preceding a quote char, and not
  			 * the second in an escape-escape sequence.
  			 */
  			if (in_quote && c == escapec)
  				last_was_esc = !last_was_esc;
  			if (c == quotec && !last_was_esc)
  				in_quote = !in_quote;
  			if (c != escapec)
  				last_was_esc = false;
  
  			/*
  			 * Updating the line count for embedded CR and/or LF chars is
  			 * necessarily a little fragile - this test is probably about the
  			 * best we can do.  (XXX it's arguable whether we should do this
  			 * at all --- is cur_lineno a physical or logical count?)
  			 */
  			if (in_quote && c == (cstate->eol_type == EOL_NL ? '\n' : '\r'))
  				cstate->cur_lineno++;
  		}
  
  		/* Process \r */
  		if (c == '\r' && (!cstate->opts.csv_mode || !in_quote))
  		{
  			/* Check for \r\n on first line, _and_ handle \r\n. */
  			if (cstate->eol_type == EOL_UNKNOWN ||
  				cstate->eol_type == EOL_CRNL)
  			{
  				/*
  				 * If need more data, go back to loop top to load it.
  				 *
  				 * Note that if we are at EOF, c will wind up as '\0' because
  				 * of the guaranteed pad of raw_buf.
  				 */
  				IF_NEED_REFILL_AND_NOT_EOF_CONTINUE(0);
  
  				/* get next char */
  				c = copy_raw_buf[raw_buf_ptr];
  
  				if (c == '\n')
  				{
  					raw_buf_ptr++;	/* eat newline */
  					cstate->eol_type = EOL_CRNL;	/* in case not set yet */
  				}
  				else
  				{
  					/* found \r, but no \n */
  					if (cstate->eol_type == EOL_CRNL)
  						ereport(ERROR,
  								(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  								 !cstate->opts.csv_mode ?
  								 errmsg("literal carriage return found in data") :
  								 errmsg("unquoted carriage return found in data"),
  								 !cstate->opts.csv_mode ?
  								 errhint("Use \"\\r\" to represent carriage return.") :
  								 errhint("Use quoted CSV field to represent carriage return.")));
  
  					/*
  					 * if we got here, it is the first line and we didn't find
  					 * \n, so don't consume the peeked character
  					 */
  					cstate->eol_type = EOL_CR;
  				}
  			}
  			else if (cstate->eol_type == EOL_NL)
  				ereport(ERROR,
  						(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  						 !cstate->opts.csv_mode ?
  						 errmsg("literal carriage return found in data") :
  						 errmsg("unquoted carriage return found in data"),
  						 !cstate->opts.csv_mode ?
  						 errhint("Use \"\\r\" to represent carriage return.") :
  						 errhint("Use quoted CSV field to represent carriage return.")));
  			/* If reach here, we have found the line terminator */
  			break;
  		}
  
  		/* Process \n */
  		if (c == '\n' && (!cstate->opts.csv_mode || !in_quote))
  		{
  			if (cstate->eol_type == EOL_CR || cstate->eol_type == EOL_CRNL)
  				ereport(ERROR,
  						(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  						 !cstate->opts.csv_mode ?
  						 errmsg("literal newline found in data") :
  						 errmsg("unquoted newline found in data"),
  						 !cstate->opts.csv_mode ?
  						 errhint("Use \"\\n\" to represent newline.") :
  						 errhint("Use quoted CSV field to represent newline.")));
  			cstate->eol_type = EOL_NL;	/* in case not set yet */
  			/* If reach here, we have found the line terminator */
  			break;
  		}
  
  		/*
  		 * In CSV mode, we only recognize \. alone on a line.  This is because
  		 * \. is a valid CSV data value.
  		 */
  		if (c == '\\' && (!cstate->opts.csv_mode || first_char_in_line))
  		{
  			char		c2;
  
  			IF_NEED_REFILL_AND_NOT_EOF_CONTINUE(0);
  			IF_NEED_REFILL_AND_EOF_BREAK(0);
  
  			/* -----
  			 * get next character
  			 * Note: we do not change c so if it isn't \., we can fall
  			 * through and continue processing for file encoding.
  			 * -----
  			 */
  			c2 = copy_raw_buf[raw_buf_ptr];
  
  			if (c2 == '.')
  			{
  				raw_buf_ptr++;	/* consume the '.' */
  
  				/*
  				 * Note: if we loop back for more data here, it does not
  				 * matter that the CSV state change checks are re-executed; we
  				 * will come back here with no important state changed.
  				 */
  				if (cstate->eol_type == EOL_CRNL)
  				{
  					/* Get the next character */
  					IF_NEED_REFILL_AND_NOT_EOF_CONTINUE(0);
  					/* if hit_eof, c2 will become '\0' */
  					c2 = copy_raw_buf[raw_buf_ptr++];
  
  					if (c2 == '\n')
  					{
  						if (!cstate->opts.csv_mode)
  							ereport(ERROR,
  									(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  									 errmsg("end-of-copy marker does not match previous newline style")));
  						else
  							NO_END_OF_COPY_GOTO;
  					}
  					else if (c2 != '\r')
  					{
  						if (!cstate->opts.csv_mode)
  							ereport(ERROR,
  									(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  									 errmsg("end-of-copy marker corrupt")));
  						else
  							NO_END_OF_COPY_GOTO;
  					}
  				}
  
  				/* Get the next character */
  				IF_NEED_REFILL_AND_NOT_EOF_CONTINUE(0);
  				/* if hit_eof, c2 will become '\0' */
  				c2 = copy_raw_buf[raw_buf_ptr++];
  
  				if (c2 != '\r' && c2 != '\n')
  				{
  					if (!cstate->opts.csv_mode)
  						ereport(ERROR,
  								(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  								 errmsg("end-of-copy marker corrupt")));
  					else
  						NO_END_OF_COPY_GOTO;
  				}
  
  				if ((cstate->eol_type == EOL_NL && c2 != '\n') ||
  					(cstate->eol_type == EOL_CRNL && c2 != '\n') ||
  					(cstate->eol_type == EOL_CR && c2 != '\r'))
  				{
  					ereport(ERROR,
  							(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  							 errmsg("end-of-copy marker does not match previous newline style")));
  				}
  
  				/*
  				 * Transfer only the data before the \. into line_buf, then
  				 * discard the data and the \. sequence.
  				 */
  				if (prev_raw_ptr > cstate->raw_buf_index)
  					appendBinaryStringInfo(&cstate->line_buf,
  										   cstate->raw_buf + cstate->raw_buf_index,
  										   prev_raw_ptr - cstate->raw_buf_index);
  				cstate->raw_buf_index = raw_buf_ptr;
  				result = true;	/* report EOF */
  				break;
  			}
  			else if (!cstate->opts.csv_mode)
  
  				/*
  				 * If we are here, it means we found a backslash followed by
  				 * something other than a period.  In non-CSV mode, anything
  				 * after a backslash is special, so we skip over that second
  				 * character too.  If we didn't do that \\. would be
  				 * considered an eof-of copy, while in non-CSV mode it is a
  				 * literal backslash followed by a period.  In CSV mode,
  				 * backslashes are not special, so we want to process the
  				 * character after the backslash just like a normal character,
  				 * so we don't increment in those cases.
  				 */
  				raw_buf_ptr++;
  		}
  
  		/*
  		 * This label is for CSV cases where \. appears at the start of a
  		 * line, but there is more text after it, meaning it was a data value.
  		 * We are more strict for \. in CSV mode because \. could be a data
  		 * value, while in non-CSV mode, \. cannot be a data value.
  		 */
  not_end_of_copy:
  
  		/*
  		 * Process all bytes of a multi-byte character as a group.
  		 *
  		 * We only support multi-byte sequences where the first byte has the
  		 * high-bit set, so as an optimization we can avoid this block
  		 * entirely if it is not set.
  		 */
  		if (cstate->encoding_embeds_ascii && IS_HIGHBIT_SET(c))
  		{
  			int			mblen;
  
  			/*
  			 * It is enough to look at the first byte in all our encodings, to
  			 * get the length.  (GB18030 is a bit special, but still works for
  			 * our purposes; see comment in pg_gb18030_mblen())
  			 */
  			mblen_str[0] = c;
  			mblen = pg_encoding_mblen(cstate->file_encoding, mblen_str);
  
  			IF_NEED_REFILL_AND_NOT_EOF_CONTINUE(mblen - 1);
  			IF_NEED_REFILL_AND_EOF_BREAK(mblen - 1);
  			raw_buf_ptr += mblen - 1;
  		}
  		first_char_in_line = false;
  	}							/* end of outer loop */
  
  	/*
  	 * Transfer any still-uncopied data to line_buf.
  	 */
  	REFILL_LINEBUF;
  
  	return result;
  }
  
  /*
   *	Return decimal value for a hexadecimal digit
   */
  static int
  GetDecimalFromHex(char hex)
  {
  	if (isdigit((unsigned char) hex))
  		return hex - '0';
  	else
  		return tolower((unsigned char) hex) - 'a' + 10;
  }
  
  /*
   * Parse the current line into separate attributes (fields),
   * performing de-escaping as needed.
   *
   * The input is in line_buf.  We use attribute_buf to hold the result
   * strings.  cstate->raw_fields[k] is set to point to the k'th attribute
   * string, or NULL when the input matches the null marker string.
   * This array is expanded as necessary.
   *
   * (Note that the caller cannot check for nulls since the returned
   * string would be the post-de-escaping equivalent, which may look
   * the same as some valid data string.)
   *
   * delim is the column delimiter string (must be just one byte for now).
   * null_print is the null marker string.  Note that this is compared to
   * the pre-de-escaped input string.
   *
   * The return value is the number of fields actually read.
   */
  static int
  CopyReadAttributesText(CopyFromState cstate)
  {
  	char		delimc = cstate->opts.delim[0];
  	int			fieldno;
  	char	   *output_ptr;
  	char	   *cur_ptr;
  	char	   *line_end_ptr;
  
  	/*
  	 * We need a special case for zero-column tables: check that the input
  	 * line is empty, and return.
  	 */
  	if (cstate->max_fields <= 0)
  	{
  		if (cstate->line_buf.len != 0)
  			ereport(ERROR,
  					(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  					 errmsg("extra data after last expected column")));
  		return 0;
  	}
  
  	resetStringInfo(&cstate->attribute_buf);
  
  	/*
  	 * The de-escaped attributes will certainly not be longer than the input
  	 * data line, so we can just force attribute_buf to be large enough and
  	 * then transfer data without any checks for enough space.  We need to do
  	 * it this way because enlarging attribute_buf mid-stream would invalidate
  	 * pointers already stored into cstate->raw_fields[].
  	 */
  	if (cstate->attribute_buf.maxlen <= cstate->line_buf.len)
  		enlargeStringInfo(&cstate->attribute_buf, cstate->line_buf.len);
  	output_ptr = cstate->attribute_buf.data;
  
  	/* set pointer variables for loop */
  	cur_ptr = cstate->line_buf.data;
  	line_end_ptr = cstate->line_buf.data + cstate->line_buf.len;
  
  	/* Outer loop iterates over fields */
  	fieldno = 0;
  	for (;;)
  	{
  		bool		found_delim = false;
  		char	   *start_ptr;
  		char	   *end_ptr;
  		int			input_len;
  		bool		saw_non_ascii = false;
  
  		/* Make sure there is enough space for the next value */
  		if (fieldno >= cstate->max_fields)
  		{
  			cstate->max_fields *= 2;
  			cstate->raw_fields =
  				repalloc(cstate->raw_fields, cstate->max_fields * sizeof(char *));
  		}
  
  		/* Remember start of field on both input and output sides */
  		start_ptr = cur_ptr;
  		cstate->raw_fields[fieldno] = output_ptr;
  
  		/*
  		 * Scan data for field.
  		 *
  		 * Note that in this loop, we are scanning to locate the end of field
  		 * and also speculatively performing de-escaping.  Once we find the
  		 * end-of-field, we can match the raw field contents against the null
  		 * marker string.  Only after that comparison fails do we know that
  		 * de-escaping is actually the right thing to do; therefore we *must
  		 * not* throw any syntax errors before we've done the null-marker
  		 * check.
  		 */
  		for (;;)
  		{
  			char		c;
  
  			end_ptr = cur_ptr;
  			if (cur_ptr >= line_end_ptr)
  				break;
  			c = *cur_ptr++;
  			if (c == delimc)
  			{
  				found_delim = true;
  				break;
  			}
  			if (c == '\\')
  			{
  				if (cur_ptr >= line_end_ptr)
  					break;
  				c = *cur_ptr++;
  				switch (c)
  				{
  					case '0':
  					case '1':
  					case '2':
  					case '3':
  					case '4':
  					case '5':
  					case '6':
  					case '7':
  						{
  							/* handle \013 */
  							int			val;
  
  							val = OCTVALUE(c);
  							if (cur_ptr < line_end_ptr)
  							{
  								c = *cur_ptr;
  								if (ISOCTAL(c))
  								{
  									cur_ptr++;
  									val = (val << 3) + OCTVALUE(c);
  									if (cur_ptr < line_end_ptr)
  									{
  										c = *cur_ptr;
  										if (ISOCTAL(c))
  										{
  											cur_ptr++;
  											val = (val << 3) + OCTVALUE(c);
  										}
  									}
  								}
  							}
  							c = val & 0377;
  							if (c == '\0' || IS_HIGHBIT_SET(c))
  								saw_non_ascii = true;
  						}
  						break;
  					case 'x':
  						/* Handle \x3F */
  						if (cur_ptr < line_end_ptr)
  						{
  							char		hexchar = *cur_ptr;
  
  							if (isxdigit((unsigned char) hexchar))
  							{
  								int			val = GetDecimalFromHex(hexchar);
  
  								cur_ptr++;
  								if (cur_ptr < line_end_ptr)
  								{
  									hexchar = *cur_ptr;
  									if (isxdigit((unsigned char) hexchar))
  									{
  										cur_ptr++;
  										val = (val << 4) + GetDecimalFromHex(hexchar);
  									}
  								}
  								c = val & 0xff;
  								if (c == '\0' || IS_HIGHBIT_SET(c))
  									saw_non_ascii = true;
  							}
  						}
  						break;
  					case 'b':
  						c = '\b';
  						break;
  					case 'f':
  						c = '\f';
  						break;
  					case 'n':
  						c = '\n';
  						break;
  					case 'r':
  						c = '\r';
  						break;
  					case 't':
  						c = '\t';
  						break;
  					case 'v':
  						c = '\v';
  						break;
  
  						/*
  						 * in all other cases, take the char after '\'
  						 * literally
  						 */
  				}
  			}
  
  			/* Add c to output string */
  			*output_ptr++ = c;
  		}
  
  		/* Check whether raw input matched null marker */
  		input_len = end_ptr - start_ptr;
  		if (input_len == cstate->opts.null_print_len &&
  			strncmp(start_ptr, cstate->opts.null_print, input_len) == 0)
  			cstate->raw_fields[fieldno] = NULL;
  		else
  		{
  			/*
  			 * At this point we know the field is supposed to contain data.
  			 *
  			 * If we de-escaped any non-7-bit-ASCII chars, make sure the
  			 * resulting string is valid data for the db encoding.
  			 */
  			if (saw_non_ascii)
  			{
  				char	   *fld = cstate->raw_fields[fieldno];
  
  				pg_verifymbstr(fld, output_ptr - fld, false);
  			}
  		}
  
  		/* Terminate attribute value in output area */
  		*output_ptr++ = '\0';
  
  		fieldno++;
  		/* Done if we hit EOL instead of a delim */
  		if (!found_delim)
  			break;
  	}
  
  	/* Clean up state of attribute_buf */
  	output_ptr--;
  	Assert(*output_ptr == '\0');
  	cstate->attribute_buf.len = (output_ptr - cstate->attribute_buf.data);
  
  	return fieldno;
  }
  
  /*
   * Parse the current line into separate attributes (fields),
   * performing de-escaping as needed.  This has exactly the same API as
   * CopyReadAttributesText, except we parse the fields according to
   * "standard" (i.e. common) CSV usage.
   */
  static int
  CopyReadAttributesCSV(CopyFromState cstate)
  {
  	char		delimc = cstate->opts.delim[0];
  	char		quotec = cstate->opts.quote[0];
  	char		escapec = cstate->opts.escape[0];
  	int			fieldno;
  	char	   *output_ptr;
  	char	   *cur_ptr;
  	char	   *line_end_ptr;
  
  	/*
  	 * We need a special case for zero-column tables: check that the input
  	 * line is empty, and return.
  	 */
  	if (cstate->max_fields <= 0)
  	{
  		if (cstate->line_buf.len != 0)
  			ereport(ERROR,
  					(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  					 errmsg("extra data after last expected column")));
  		return 0;
  	}
  
  	resetStringInfo(&cstate->attribute_buf);
  
  	/*
  	 * The de-escaped attributes will certainly not be longer than the input
  	 * data line, so we can just force attribute_buf to be large enough and
  	 * then transfer data without any checks for enough space.  We need to do
  	 * it this way because enlarging attribute_buf mid-stream would invalidate
  	 * pointers already stored into cstate->raw_fields[].
  	 */
  	if (cstate->attribute_buf.maxlen <= cstate->line_buf.len)
  		enlargeStringInfo(&cstate->attribute_buf, cstate->line_buf.len);
  	output_ptr = cstate->attribute_buf.data;
  
  	/* set pointer variables for loop */
  	cur_ptr = cstate->line_buf.data;
  	line_end_ptr = cstate->line_buf.data + cstate->line_buf.len;
  
  	/* Outer loop iterates over fields */
  	fieldno = 0;
  	for (;;)
  	{
  		bool		found_delim = false;
  		bool		saw_quote = false;
  		char	   *start_ptr;
  		char	   *end_ptr;
  		int			input_len;
  
  		/* Make sure there is enough space for the next value */
  		if (fieldno >= cstate->max_fields)
  		{
  			cstate->max_fields *= 2;
  			cstate->raw_fields =
  				repalloc(cstate->raw_fields, cstate->max_fields * sizeof(char *));
  		}
  
  		/* Remember start of field on both input and output sides */
  		start_ptr = cur_ptr;
  		cstate->raw_fields[fieldno] = output_ptr;
  
  		/*
  		 * Scan data for field,
  		 *
  		 * The loop starts in "not quote" mode and then toggles between that
  		 * and "in quote" mode. The loop exits normally if it is in "not
  		 * quote" mode and a delimiter or line end is seen.
  		 */
  		for (;;)
  		{
  			char		c;
  
  			/* Not in quote */
  			for (;;)
  			{
  				end_ptr = cur_ptr;
  				if (cur_ptr >= line_end_ptr)
  					goto endfield;
  				c = *cur_ptr++;
  				/* unquoted field delimiter */
  				if (c == delimc)
  				{
  					found_delim = true;
  					goto endfield;
  				}
  				/* start of quoted field (or part of field) */
  				if (c == quotec)
  				{
  					saw_quote = true;
  					break;
  				}
  				/* Add c to output string */
  				*output_ptr++ = c;
  			}
  
  			/* In quote */
  			for (;;)
  			{
  				end_ptr = cur_ptr;
  				if (cur_ptr >= line_end_ptr)
  					ereport(ERROR,
  							(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  							 errmsg("unterminated CSV quoted field")));
  
  				c = *cur_ptr++;
  
  				/* escape within a quoted field */
  				if (c == escapec)
  				{
  					/*
  					 * peek at the next char if available, and escape it if it
  					 * is an escape char or a quote char
  					 */
  					if (cur_ptr < line_end_ptr)
  					{
  						char		nextc = *cur_ptr;
  
  						if (nextc == escapec || nextc == quotec)
  						{
  							*output_ptr++ = nextc;
  							cur_ptr++;
  							continue;
  						}
  					}
  				}
  
  				/*
  				 * end of quoted field. Must do this test after testing for
  				 * escape in case quote char and escape char are the same
  				 * (which is the common case).
  				 */
  				if (c == quotec)
  					break;
  
  				/* Add c to output string */
  				*output_ptr++ = c;
  			}
  		}
  endfield:
  
  		/* Terminate attribute value in output area */
  		*output_ptr++ = '\0';
  
  		/* Check whether raw input matched null marker */
  		input_len = end_ptr - start_ptr;
  		if (!saw_quote && input_len == cstate->opts.null_print_len &&
  			strncmp(start_ptr, cstate->opts.null_print, input_len) == 0)
  			cstate->raw_fields[fieldno] = NULL;
  
  		fieldno++;
  		/* Done if we hit EOL instead of a delim */
  		if (!found_delim)
  			break;
  	}
  
  	/* Clean up state of attribute_buf */
  	output_ptr--;
  	Assert(*output_ptr == '\0');
  	cstate->attribute_buf.len = (output_ptr - cstate->attribute_buf.data);
  
  	return fieldno;
  }
  
  
  /*
   * Read a binary attribute
   */
  static Datum
  CopyReadBinaryAttribute(CopyFromState cstate, FmgrInfo *flinfo,
  						Oid typioparam, int32 typmod,
  						bool *isnull)
  {
  	int32		fld_size;
  	Datum		result;
  
  	if (!CopyGetInt32(cstate, &fld_size))
  		ereport(ERROR,
  				(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  				 errmsg("unexpected EOF in COPY data")));
  	if (fld_size == -1)
  	{
  		*isnull = true;
  		return ReceiveFunctionCall(flinfo, NULL, typioparam, typmod);
  	}
  	if (fld_size < 0)
  		ereport(ERROR,
  				(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  				 errmsg("invalid field size")));
  
  	/* reset attribute_buf to empty, and load raw data in it */
  	resetStringInfo(&cstate->attribute_buf);
  
  	enlargeStringInfo(&cstate->attribute_buf, fld_size);
  	if (CopyReadBinaryData(cstate, cstate->attribute_buf.data,
  						   fld_size) != fld_size)
  		ereport(ERROR,
  				(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
  				 errmsg("unexpected EOF in COPY data")));
  
  	cstate->attribute_buf.len = fld_size;
  	cstate->attribute_buf.data[fld_size] = '\0';
  
  	/* Call the column type's binary input converter */
  	result = ReceiveFunctionCall(flinfo, &cstate->attribute_buf,
  								 typioparam, typmod);
  
  	/* Trouble if it didn't eat the whole buffer */
  	if (cstate->attribute_buf.cursor != cstate->attribute_buf.len)
  		ereport(ERROR,
  				(errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
  				 errmsg("incorrect binary data format")));
  
  	*isnull = false;
  	return result;
  }
  