copy.c

关系型数据库 Postgresql 6.5.2

		pfree(elements);
		pfree(typmod);
	}

	/* comments in execUtils.c */
	if (has_index)
	{
		for (i = 0; i < n_indices; i++)
		{
			if (index_rels[i] == NULL)
				continue;
			if ((index_rels[i])->rd_rel->relam != BTREE_AM_OID &&
				(index_rels[i])->rd_rel->relam != HASH_AM_OID)
				UnlockRelation(index_rels[i], AccessExclusiveLock);
			index_close(index_rels[i]);
		}
	}
	heap_close(rel);
}



static Oid
GetOutputFunction(Oid type)
{
	HeapTuple	typeTuple;

	typeTuple = SearchSysCacheTuple(TYPOID,
									ObjectIdGetDatum(type),
									0, 0, 0);

	if (HeapTupleIsValid(typeTuple))
		return (int) ((Form_pg_type) GETSTRUCT(typeTuple))->typoutput;

	elog(ERROR, "GetOutputFunction: Cache lookup of type %u failed", type);
	return InvalidOid;
}

static Oid
GetTypeElement(Oid type)
{
	HeapTuple	typeTuple;

	typeTuple = SearchSysCacheTuple(TYPOID,
									ObjectIdGetDatum(type),
									0, 0, 0);

	if (HeapTupleIsValid(typeTuple))
		return (int) ((Form_pg_type) GETSTRUCT(typeTuple))->typelem;

	elog(ERROR, "GetOutputFunction: Cache lookup of type %d failed", type);
	return InvalidOid;
}

static Oid
GetInputFunction(Oid type)
{
	HeapTuple	typeTuple;

	typeTuple = SearchSysCacheTuple(TYPOID,
									ObjectIdGetDatum(type),
									0, 0, 0);

	if (HeapTupleIsValid(typeTuple))
		return (int) ((Form_pg_type) GETSTRUCT(typeTuple))->typinput;

	elog(ERROR, "GetInputFunction: Cache lookup of type %u failed", type);
	return InvalidOid;
}

static Oid
IsTypeByVal(Oid type)
{
	HeapTuple	typeTuple;

	typeTuple = SearchSysCacheTuple(TYPOID,
									ObjectIdGetDatum(type),
									0, 0, 0);

	if (HeapTupleIsValid(typeTuple))
		return (int) ((Form_pg_type) GETSTRUCT(typeTuple))->typbyval;

	elog(ERROR, "GetInputFunction: Cache lookup of type %u failed", type);

	return InvalidOid;
}

/*
 * Given the OID of a relation, return an array of index relation descriptors
 * and the number of index relations.  These relation descriptors are open
 * using heap_open().
 *
 * Space for the array itself is palloc'ed.
 */

typedef struct rel_list
{
	Oid			index_rel_oid;
	struct rel_list *next;
} RelationList;

static void
GetIndexRelations(Oid main_relation_oid,
				  int *n_indices,
				  Relation **index_rels)
{
	RelationList *head,
			   *scan;
	Relation	pg_index_rel;
	HeapScanDesc scandesc;
	Oid			index_relation_oid;
	HeapTuple	tuple;
	TupleDesc	tupDesc;
	int			i;
	bool		isnull;

	pg_index_rel = heap_openr(IndexRelationName);
	scandesc = heap_beginscan(pg_index_rel, 0, SnapshotNow, 0, NULL);
	tupDesc = RelationGetDescr(pg_index_rel);

	*n_indices = 0;

	head = (RelationList *) palloc(sizeof(RelationList));
	scan = head;
	head->next = NULL;

	while (HeapTupleIsValid(tuple = heap_getnext(scandesc, 0)))
	{

		index_relation_oid = (Oid) DatumGetInt32(heap_getattr(tuple, 2,
													  tupDesc, &isnull));
		if (index_relation_oid == main_relation_oid)
		{
			scan->index_rel_oid = (Oid) DatumGetInt32(heap_getattr(tuple,
												Anum_pg_index_indexrelid,
													  tupDesc, &isnull));
			(*n_indices)++;
			scan->next = (RelationList *) palloc(sizeof(RelationList));
			scan = scan->next;
		}
	}

	heap_endscan(scandesc);
	heap_close(pg_index_rel);

	/* We cannot trust to relhasindex of the main_relation now, so... */
	if (*n_indices == 0)
		return;

	*index_rels = (Relation *) palloc(*n_indices * sizeof(Relation));

	for (i = 0, scan = head; i < *n_indices; i++, scan = scan->next)
	{
		(*index_rels)[i] = index_open(scan->index_rel_oid);
		/* comments in execUtils.c */
		if ((*index_rels)[i] != NULL &&
			((*index_rels)[i])->rd_rel->relam != BTREE_AM_OID &&
			((*index_rels)[i])->rd_rel->relam != HASH_AM_OID)
			LockRelation((*index_rels)[i], AccessExclusiveLock);
	}

	for (i = 0, scan = head; i < *n_indices + 1; i++)
	{
		scan = head->next;
		pfree(head);
		head = scan;
	}
}

#define EXT_ATTLEN	(5 * BLCKSZ)

/*
   returns 1 is c is in s
*/
static bool
inString(char c, char *s)
{
	int			i;

	if (s)
	{
		i = 0;
		while (s[i] != '\0')
		{
			if (s[i] == c)
				return 1;
			i++;
		}
	}
	return 0;
}

#ifdef COPY_PATCH
/*
 * Reads input from fp until an end of line is seen.
 */

static void
CopyReadNewline(FILE *fp, int *newline)
{
	if (!*newline)
	{
		elog(NOTICE, "CopyReadNewline: line %d - extra fields ignored", lineno);
		while (!CopyGetEof(fp) && (CopyGetChar(fp) != '\n'));
	}
	*newline = 0;
}

#endif

/*
 * Reads input from fp until eof is seen.  If we are reading from standard
 * input, AND we see a dot on a line by itself (a dot followed immediately
 * by a newline), we exit as if we saw eof.  This is so that copy pipelines
 * can be used as standard input.
 */

static char *
#ifdef COPY_PATCH
CopyReadAttribute(FILE *fp, bool *isnull, char *delim, int *newline)
#else
CopyReadAttribute(FILE *fp, bool *isnull, char *delim)
#endif
{
	static char attribute[EXT_ATTLEN];
	char		c;
	int			done = 0;
	int			i = 0;

#ifdef MULTIBYTE
	int			mblen;
	int			encoding;
	unsigned char s[2];
	int			j;

#endif

#ifdef MULTIBYTE
	encoding = pg_get_client_encoding();
	s[1] = 0;
#endif

#ifdef COPY_PATCH
	/* if last delimiter was a newline return a NULL attribute */
	if (*newline)
	{
		*isnull = (bool) true;
		return NULL;
	}
#endif

	*isnull = (bool) false;		/* set default */
	if (CopyGetEof(fp))
		return NULL;

	while (!done)
	{
		c = CopyGetChar(fp);

		if (CopyGetEof(fp))
			return NULL;
		else if (c == '\\')
		{
			c = CopyGetChar(fp);
			if (CopyGetEof(fp))
				return NULL;
			switch (c)
			{
				case '0':
				case '1':
				case '2':
				case '3':
				case '4':
				case '5':
				case '6':
				case '7':
					{
						int			val;

						val = VALUE(c);
						c = CopyPeekChar(fp);
						if (ISOCTAL(c))
						{
							val = (val << 3) + VALUE(c);
							CopyDonePeek(fp, c, 1);		/* Pick up the
														 * character! */
							c = CopyPeekChar(fp);
							if (ISOCTAL(c))
							{
								CopyDonePeek(fp, c, 1); /* pick up! */
								val = (val << 3) + VALUE(c);
							}
							else
							{
								if (CopyGetEof(fp))
								{
									CopyDonePeek(fp, c, 1);		/* pick up */
									return NULL;
								}
								CopyDonePeek(fp, c, 0); /* Return to stream! */
							}
						}
						else
						{
							if (CopyGetEof(fp))
								return NULL;
							CopyDonePeek(fp, c, 0);		/* Return to stream! */
						}
						c = val & 0377;
					}
					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;
				case 'N':
					attribute[0] = '\0';		/* just to be safe */
					*isnull = (bool) true;
					break;
				case '.':
					c = CopyGetChar(fp);
					if (c != '\n')
						elog(ERROR, "CopyReadAttribute - end of record marker corrupted. line: %d", lineno);
					return NULL;
					break;
			}
		}
		else if (inString(c, delim) || c == '\n')
		{
#ifdef COPY_PATCH
			if (c == '\n')
				*newline = 1;
#endif
			done = 1;
		}
		if (!done)
			attribute[i++] = c;
#ifdef MULTIBYTE
		s[0] = c;
		mblen = pg_encoding_mblen(encoding, s);
		mblen--;
		for (j = 0; j < mblen; j++)
		{
			c = CopyGetChar(fp);
			if (CopyGetEof(fp))
				return NULL;
			attribute[i++] = c;
		}
#endif
		if (i == EXT_ATTLEN - 1)
			elog(ERROR, "CopyReadAttribute - attribute length too long. line: %d", lineno);
	}
	attribute[i] = '\0';
#ifdef MULTIBYTE
	return (pg_client_to_server((unsigned char *) attribute, strlen(attribute)));
#else
	return &attribute[0];
#endif
}

static void
CopyAttributeOut(FILE *fp, char *server_string, char *delim, int is_array)
{
	char	   *string;
	char		c;

#ifdef MULTIBYTE
	int			mblen;
	int			encoding;
	int			i;

#endif

#ifdef MULTIBYTE
	string = pg_server_to_client(server_string, strlen(server_string));
	encoding = pg_get_client_encoding();
#else
	string = server_string;
#endif

#ifdef MULTIBYTE
	for (; (mblen = pg_encoding_mblen(encoding, string)) &&
		 ((c = *string) != '\0'); string += mblen)
#else
	for (; (c = *string) != '\0'; string++)
#endif
	{
		if (c == delim[0] || c == '\n' ||
			(c == '\\' && !is_array))
			CopySendChar('\\', fp);
		else if (c == '\\' && is_array)
		{
			if (*(string + 1) == '\\')
			{
				/* translate \\ to \\\\ */
				CopySendChar('\\', fp);
				CopySendChar('\\', fp);
				CopySendChar('\\', fp);
				string++;
			}
			else if (*(string + 1) == '"')
			{
				/* translate \" to \\\" */
				CopySendChar('\\', fp);
				CopySendChar('\\', fp);
			}
		}
#ifdef MULTIBYTE
		for (i = 0; i < mblen; i++)
			CopySendChar(*(string + i), fp);
#else
		CopySendChar(*string, fp);
#endif
	}
}

/*
 * Returns the number of tuples in a relation.	Unfortunately, currently
 * must do a scan of the entire relation to determine this.
 *
 * relation is expected to be an open relation descriptor.
 */
static int
CountTuples(Relation relation)
{
	HeapScanDesc scandesc;
	HeapTuple	tuple;

	int			i;

	scandesc = heap_beginscan(relation, 0, QuerySnapshot, 0, NULL);

	i = 0;
	while (HeapTupleIsValid(tuple = heap_getnext(scandesc, 0)))
		i++;
	heap_endscan(scandesc);
	return i;
}