Add libpqtypes static library so we don't have to reverse engineer Postgres' binary formats.

2 files changed, 635 insertions, 0 deletions

diff --git a/Frameworks/PostgresKit/Libs/libpq/include/libpq-fe.h b/Frameworks/PostgresKit/Libs/libpq/include/libpq-fe.h
new file mode 100644
index 00000000..d7802753
--- /dev/null
+++ b/Frameworks/PostgresKit/Libs/libpq/include/libpq-fe.h
@@ -0,0 +1,576 @@
+/*-------------------------------------------------------------------------
+ *
+ * libpq-fe.h
+ *	  This file contains definitions for structures and
+ *	  externs for functions used by frontend postgres applications.
+ *
+ * Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/interfaces/libpq/libpq-fe.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef LIBPQ_FE_H
+#define LIBPQ_FE_H
+
+#ifdef __cplusplus
+extern		"C"
+{
+#endif
+
+#include <stdio.h>
+
+/*
+ * postgres_ext.h defines the backend's externally visible types,
+ * such as Oid.
+ */
+#include "postgres_ext.h"
+
+/*
+ * Option flags for PQcopyResult
+ */
+#define PG_COPYRES_ATTRS		  0x01
+#define PG_COPYRES_TUPLES		  0x02	/* Implies PG_COPYRES_ATTRS */
+#define PG_COPYRES_EVENTS		  0x04
+#define PG_COPYRES_NOTICEHOOKS	  0x08
+
+/* Application-visible enum types */
+
+typedef enum
+{
+	/*
+	 * Although it is okay to add to this list, values which become unused
+	 * should never be removed, nor should constants be redefined - that would
+	 * break compatibility with existing code.
+	 */
+	CONNECTION_OK,
+	CONNECTION_BAD,
+	/* Non-blocking mode only below here */
+
+	/*
+	 * The existence of these should never be relied upon - they should only
+	 * be used for user feedback or similar purposes.
+	 */
+	CONNECTION_STARTED,			/* Waiting for connection to be made.  */
+	CONNECTION_MADE,			/* Connection OK; waiting to send.	   */
+	CONNECTION_AWAITING_RESPONSE,		/* Waiting for a response from the
+										 * postmaster.		  */
+	CONNECTION_AUTH_OK,			/* Received authentication; waiting for
+								 * backend startup. */
+	CONNECTION_SETENV,			/* Negotiating environment. */
+	CONNECTION_SSL_STARTUP,		/* Negotiating SSL. */
+	CONNECTION_NEEDED			/* Internal state: connect() needed */
+} ConnStatusType;
+
+typedef enum
+{
+	PGRES_POLLING_FAILED = 0,
+	PGRES_POLLING_READING,		/* These two indicate that one may	  */
+	PGRES_POLLING_WRITING,		/* use select before polling again.   */
+	PGRES_POLLING_OK,
+	PGRES_POLLING_ACTIVE		/* unused; keep for awhile for backwards
+								 * compatibility */
+} PostgresPollingStatusType;
+
+typedef enum
+{
+	PGRES_EMPTY_QUERY = 0,		/* empty query string was executed */
+	PGRES_COMMAND_OK,			/* a query command that doesn't return
+								 * anything was executed properly by the
+								 * backend */
+	PGRES_TUPLES_OK,			/* a query command that returns tuples was
+								 * executed properly by the backend, PGresult
+								 * contains the result tuples */
+	PGRES_COPY_OUT,				/* Copy Out data transfer in progress */
+	PGRES_COPY_IN,				/* Copy In data transfer in progress */
+	PGRES_BAD_RESPONSE,			/* an unexpected response was recv'd from the
+								 * backend */
+	PGRES_NONFATAL_ERROR,		/* notice or warning message */
+	PGRES_FATAL_ERROR,			/* query failed */
+	PGRES_COPY_BOTH				/* Copy In/Out data transfer in progress */
+} ExecStatusType;
+
+typedef enum
+{
+	PQTRANS_IDLE,				/* connection idle */
+	PQTRANS_ACTIVE,				/* command in progress */
+	PQTRANS_INTRANS,			/* idle, within transaction block */
+	PQTRANS_INERROR,			/* idle, within failed transaction */
+	PQTRANS_UNKNOWN				/* cannot determine status */
+} PGTransactionStatusType;
+
+typedef enum
+{
+	PQERRORS_TERSE,				/* single-line error messages */
+	PQERRORS_DEFAULT,			/* recommended style */
+	PQERRORS_VERBOSE			/* all the facts, ma'am */
+} PGVerbosity;
+
+typedef enum
+{
+	PQPING_OK,					/* server is accepting connections */
+	PQPING_REJECT,				/* server is alive but rejecting connections */
+	PQPING_NO_RESPONSE,			/* could not establish connection */
+	PQPING_NO_ATTEMPT			/* connection not attempted (bad params) */
+} PGPing;
+
+/* PGconn encapsulates a connection to the backend.
+ * The contents of this struct are not supposed to be known to applications.
+ */
+typedef struct pg_conn PGconn;
+
+/* PGresult encapsulates the result of a query (or more precisely, of a single
+ * SQL command --- a query string given to PQsendQuery can contain multiple
+ * commands and thus return multiple PGresult objects).
+ * The contents of this struct are not supposed to be known to applications.
+ */
+typedef struct pg_result PGresult;
+
+/* PGcancel encapsulates the information needed to cancel a running
+ * query on an existing connection.
+ * The contents of this struct are not supposed to be known to applications.
+ */
+typedef struct pg_cancel PGcancel;
+
+/* PGnotify represents the occurrence of a NOTIFY message.
+ * Ideally this would be an opaque typedef, but it's so simple that it's
+ * unlikely to change.
+ * NOTE: in Postgres 6.4 and later, the be_pid is the notifying backend's,
+ * whereas in earlier versions it was always your own backend's PID.
+ */
+typedef struct pgNotify
+{
+	char	   *relname;		/* notification condition name */
+	int			be_pid;			/* process ID of notifying server process */
+	char	   *extra;			/* notification parameter */
+	/* Fields below here are private to libpq; apps should not use 'em */
+	struct pgNotify *next;		/* list link */
+} PGnotify;
+
+/* Function types for notice-handling callbacks */
+typedef void (*PQnoticeReceiver) (void *arg, const PGresult *res);
+typedef void (*PQnoticeProcessor) (void *arg, const char *message);
+
+/* Print options for PQprint() */
+typedef char pqbool;
+
+typedef struct _PQprintOpt
+{
+	pqbool		header;			/* print output field headings and row count */
+	pqbool		align;			/* fill align the fields */
+	pqbool		standard;		/* old brain dead format */
+	pqbool		html3;			/* output html tables */
+	pqbool		expanded;		/* expand tables */
+	pqbool		pager;			/* use pager for output if needed */
+	char	   *fieldSep;		/* field separator */
+	char	   *tableOpt;		/* insert to HTML <table ...> */
+	char	   *caption;		/* HTML <caption> */
+	char	  **fieldName;		/* null terminated array of replacement field
+								 * names */
+} PQprintOpt;
+
+/* ----------------
+ * Structure for the conninfo parameter definitions returned by PQconndefaults
+ * or PQconninfoParse.
+ *
+ * All fields except "val" point at static strings which must not be altered.
+ * "val" is either NULL or a malloc'd current-value string.  PQconninfoFree()
+ * will release both the val strings and the PQconninfoOption array itself.
+ * ----------------
+ */
+typedef struct _PQconninfoOption
+{
+	char	   *keyword;		/* The keyword of the option			*/
+	char	   *envvar;			/* Fallback environment variable name	*/
+	char	   *compiled;		/* Fallback compiled in default value	*/
+	char	   *val;			/* Option's current value, or NULL		 */
+	char	   *label;			/* Label for field in connect dialog	*/
+	char	   *dispchar;		/* Indicates how to display this field in a
+								 * connect dialog. Values are: "" Display
+								 * entered value as is "*" Password field -
+								 * hide value "D"  Debug option - don't show
+								 * by default */
+	int			dispsize;		/* Field size in characters for dialog	*/
+} PQconninfoOption;
+
+/* ----------------
+ * PQArgBlock -- structure for PQfn() arguments
+ * ----------------
+ */
+typedef struct
+{
+	int			len;
+	int			isint;
+	union
+	{
+		int		   *ptr;		/* can't use void (dec compiler barfs)	 */
+		int			integer;
+	}			u;
+} PQArgBlock;
+
+/* ----------------
+ * PGresAttDesc -- Data about a single attribute (column) of a query result
+ * ----------------
+ */
+typedef struct pgresAttDesc
+{
+	char	   *name;			/* column name */
+	Oid			tableid;		/* source table, if known */
+	int			columnid;		/* source column, if known */
+	int			format;			/* format code for value (text/binary) */
+	Oid			typid;			/* type id */
+	int			typlen;			/* type size */
+	int			atttypmod;		/* type-specific modifier info */
+} PGresAttDesc;
+
+/* ----------------
+ * Exported functions of libpq
+ * ----------------
+ */
+
+/* ===	in fe-connect.c === */
+
+/* make a new client connection to the backend */
+/* Asynchronous (non-blocking) */
+extern PGconn *PQconnectStart(const char *conninfo);
+extern PGconn *PQconnectStartParams(const char **keywords,
+					 const char **values, int expand_dbname);
+extern PostgresPollingStatusType PQconnectPoll(PGconn *conn);
+
+/* Synchronous (blocking) */
+extern PGconn *PQconnectdb(const char *conninfo);
+extern PGconn *PQconnectdbParams(const char **keywords,
+				  const char **values, int expand_dbname);
+extern PGconn *PQsetdbLogin(const char *pghost, const char *pgport,
+			 const char *pgoptions, const char *pgtty,
+			 const char *dbName,
+			 const char *login, const char *pwd);
+
+#define PQsetdb(M_PGHOST,M_PGPORT,M_PGOPT,M_PGTTY,M_DBNAME)  \
+	PQsetdbLogin(M_PGHOST, M_PGPORT, M_PGOPT, M_PGTTY, M_DBNAME, NULL, NULL)
+
+/* close the current connection and free the PGconn data structure */
+extern void PQfinish(PGconn *conn);
+
+/* get info about connection options known to PQconnectdb */
+extern PQconninfoOption *PQconndefaults(void);
+
+/* parse connection options in same way as PQconnectdb */
+extern PQconninfoOption *PQconninfoParse(const char *conninfo, char **errmsg);
+
+/* free the data structure returned by PQconndefaults() or PQconninfoParse() */
+extern void PQconninfoFree(PQconninfoOption *connOptions);
+
+/*
+ * close the current connection and restablish a new one with the same
+ * parameters
+ */
+/* Asynchronous (non-blocking) */
+extern int	PQresetStart(PGconn *conn);
+extern PostgresPollingStatusType PQresetPoll(PGconn *conn);
+
+/* Synchronous (blocking) */
+extern void PQreset(PGconn *conn);
+
+/* request a cancel structure */
+extern PGcancel *PQgetCancel(PGconn *conn);
+
+/* free a cancel structure */
+extern void PQfreeCancel(PGcancel *cancel);
+
+/* issue a cancel request */
+extern int	PQcancel(PGcancel *cancel, char *errbuf, int errbufsize);
+
+/* backwards compatible version of PQcancel; not thread-safe */
+extern int	PQrequestCancel(PGconn *conn);
+
+/* Accessor functions for PGconn objects */
+extern char *PQdb(const PGconn *conn);
+extern char *PQuser(const PGconn *conn);
+extern char *PQpass(const PGconn *conn);
+extern char *PQhost(const PGconn *conn);
+extern char *PQport(const PGconn *conn);
+extern char *PQtty(const PGconn *conn);
+extern char *PQoptions(const PGconn *conn);
+extern ConnStatusType PQstatus(const PGconn *conn);
+extern PGTransactionStatusType PQtransactionStatus(const PGconn *conn);
+extern const char *PQparameterStatus(const PGconn *conn,
+				  const char *paramName);
+extern int	PQprotocolVersion(const PGconn *conn);
+extern int	PQserverVersion(const PGconn *conn);
+extern char *PQerrorMessage(const PGconn *conn);
+extern int	PQsocket(const PGconn *conn);
+extern int	PQbackendPID(const PGconn *conn);
+extern int	PQconnectionNeedsPassword(const PGconn *conn);
+extern int	PQconnectionUsedPassword(const PGconn *conn);
+extern int	PQclientEncoding(const PGconn *conn);
+extern int	PQsetClientEncoding(PGconn *conn, const char *encoding);
+
+/* Get the OpenSSL structure associated with a connection. Returns NULL for
+ * unencrypted connections or if any other TLS library is in use. */
+extern void *PQgetssl(PGconn *conn);
+
+/* Tell libpq whether it needs to initialize OpenSSL */
+extern void PQinitSSL(int do_init);
+
+/* More detailed way to tell libpq whether it needs to initialize OpenSSL */
+extern void PQinitOpenSSL(int do_ssl, int do_crypto);
+
+/* Set verbosity for PQerrorMessage and PQresultErrorMessage */
+extern PGVerbosity PQsetErrorVerbosity(PGconn *conn, PGVerbosity verbosity);
+
+/* Enable/disable tracing */
+extern void PQtrace(PGconn *conn, FILE *debug_port);
+extern void PQuntrace(PGconn *conn);
+
+/* Override default notice handling routines */
+extern PQnoticeReceiver PQsetNoticeReceiver(PGconn *conn,
+					PQnoticeReceiver proc,
+					void *arg);
+extern PQnoticeProcessor PQsetNoticeProcessor(PGconn *conn,
+					 PQnoticeProcessor proc,
+					 void *arg);
+
+/*
+ *	   Used to set callback that prevents concurrent access to
+ *	   non-thread safe functions that libpq needs.
+ *	   The default implementation uses a libpq internal mutex.
+ *	   Only required for multithreaded apps that use kerberos
+ *	   both within their app and for postgresql connections.
+ */
+typedef void (*pgthreadlock_t) (int acquire);
+
+extern pgthreadlock_t PQregisterThreadLock(pgthreadlock_t newhandler);
+
+/* === in fe-exec.c === */
+
+/* Simple synchronous query */
+extern PGresult *PQexec(PGconn *conn, const char *query);
+extern PGresult *PQexecParams(PGconn *conn,
+			 const char *command,
+			 int nParams,
+			 const Oid *paramTypes,
+			 const char *const * paramValues,
+			 const int *paramLengths,
+			 const int *paramFormats,
+			 int resultFormat);
+extern PGresult *PQprepare(PGconn *conn, const char *stmtName,
+		  const char *query, int nParams,
+		  const Oid *paramTypes);
+extern PGresult *PQexecPrepared(PGconn *conn,
+			   const char *stmtName,
+			   int nParams,
+			   const char *const * paramValues,
+			   const int *paramLengths,
+			   const int *paramFormats,
+			   int resultFormat);
+
+/* Interface for multiple-result or asynchronous queries */
+extern int	PQsendQuery(PGconn *conn, const char *query);
+extern int PQsendQueryParams(PGconn *conn,
+				  const char *command,
+				  int nParams,
+				  const Oid *paramTypes,
+				  const char *const * paramValues,
+				  const int *paramLengths,
+				  const int *paramFormats,
+				  int resultFormat);
+extern int PQsendPrepare(PGconn *conn, const char *stmtName,
+			  const char *query, int nParams,
+			  const Oid *paramTypes);
+extern int PQsendQueryPrepared(PGconn *conn,
+					const char *stmtName,
+					int nParams,
+					const char *const * paramValues,
+					const int *paramLengths,
+					const int *paramFormats,
+					int resultFormat);
+extern PGresult *PQgetResult(PGconn *conn);
+
+/* Routines for managing an asynchronous query */
+extern int	PQisBusy(PGconn *conn);
+extern int	PQconsumeInput(PGconn *conn);
+
+/* LISTEN/NOTIFY support */
+extern PGnotify *PQnotifies(PGconn *conn);
+
+/* Routines for copy in/out */
+extern int	PQputCopyData(PGconn *conn, const char *buffer, int nbytes);
+extern int	PQputCopyEnd(PGconn *conn, const char *errormsg);
+extern int	PQgetCopyData(PGconn *conn, char **buffer, int async);
+
+/* Deprecated routines for copy in/out */
+extern int	PQgetline(PGconn *conn, char *string, int length);
+extern int	PQputline(PGconn *conn, const char *string);
+extern int	PQgetlineAsync(PGconn *conn, char *buffer, int bufsize);
+extern int	PQputnbytes(PGconn *conn, const char *buffer, int nbytes);
+extern int	PQendcopy(PGconn *conn);
+
+/* Set blocking/nonblocking connection to the backend */
+extern int	PQsetnonblocking(PGconn *conn, int arg);
+extern int	PQisnonblocking(const PGconn *conn);
+extern int	PQisthreadsafe(void);
+extern PGPing PQping(const char *conninfo);
+extern PGPing PQpingParams(const char **keywords,
+			 const char **values, int expand_dbname);
+
+/* Force the write buffer to be written (or at least try) */
+extern int	PQflush(PGconn *conn);
+
+/*
+ * "Fast path" interface --- not really recommended for application
+ * use
+ */
+extern PGresult *PQfn(PGconn *conn,
+	 int fnid,
+	 int *result_buf,
+	 int *result_len,
+	 int result_is_int,
+	 const PQArgBlock *args,
+	 int nargs);
+
+/* Accessor functions for PGresult objects */
+extern ExecStatusType PQresultStatus(const PGresult *res);
+extern char *PQresStatus(ExecStatusType status);
+extern char *PQresultErrorMessage(const PGresult *res);
+extern char *PQresultErrorField(const PGresult *res, int fieldcode);
+extern int	PQntuples(const PGresult *res);
+extern int	PQnfields(const PGresult *res);
+extern int	PQbinaryTuples(const PGresult *res);
+extern char *PQfname(const PGresult *res, int field_num);
+extern int	PQfnumber(const PGresult *res, const char *field_name);
+extern Oid	PQftable(const PGresult *res, int field_num);
+extern int	PQftablecol(const PGresult *res, int field_num);
+extern int	PQfformat(const PGresult *res, int field_num);
+extern Oid	PQftype(const PGresult *res, int field_num);
+extern int	PQfsize(const PGresult *res, int field_num);
+extern int	PQfmod(const PGresult *res, int field_num);
+extern char *PQcmdStatus(PGresult *res);
+extern char *PQoidStatus(const PGresult *res);	/* old and ugly */
+extern Oid	PQoidValue(const PGresult *res);	/* new and improved */
+extern char *PQcmdTuples(PGresult *res);
+extern char *PQgetvalue(const PGresult *res, int tup_num, int field_num);
+extern int	PQgetlength(const PGresult *res, int tup_num, int field_num);
+extern int	PQgetisnull(const PGresult *res, int tup_num, int field_num);
+extern int	PQnparams(const PGresult *res);
+extern Oid	PQparamtype(const PGresult *res, int param_num);
+
+/* Describe prepared statements and portals */
+extern PGresult *PQdescribePrepared(PGconn *conn, const char *stmt);
+extern PGresult *PQdescribePortal(PGconn *conn, const char *portal);
+extern int	PQsendDescribePrepared(PGconn *conn, const char *stmt);
+extern int	PQsendDescribePortal(PGconn *conn, const char *portal);
+
+/* Delete a PGresult */
+extern void PQclear(PGresult *res);
+
+/* For freeing other alloc'd results, such as PGnotify structs */
+extern void PQfreemem(void *ptr);
+
+/* Exists for backward compatibility.  bjm 2003-03-24 */
+#define PQfreeNotify(ptr) PQfreemem(ptr)
+
+/* Error when no password was given. */
+/* Note: depending on this is deprecated; use PQconnectionNeedsPassword(). */
+#define PQnoPasswordSupplied	"fe_sendauth: no password supplied\n"
+
+/* Create and manipulate PGresults */
+extern PGresult *PQmakeEmptyPGresult(PGconn *conn, ExecStatusType status);
+extern PGresult *PQcopyResult(const PGresult *src, int flags);
+extern int	PQsetResultAttrs(PGresult *res, int numAttributes, PGresAttDesc *attDescs);
+extern void *PQresultAlloc(PGresult *res, size_t nBytes);
+extern int	PQsetvalue(PGresult *res, int tup_num, int field_num, char *value, int len);
+
+/* Quoting strings before inclusion in queries. */
+extern size_t PQescapeStringConn(PGconn *conn,
+				   char *to, const char *from, size_t length,
+				   int *error);
+extern char *PQescapeLiteral(PGconn *conn, const char *str, size_t len);
+extern char *PQescapeIdentifier(PGconn *conn, const char *str, size_t len);
+extern unsigned char *PQescapeByteaConn(PGconn *conn,
+				  const unsigned char *from, size_t from_length,
+				  size_t *to_length);
+extern unsigned char *PQunescapeBytea(const unsigned char *strtext,
+				size_t *retbuflen);
+
+/* These forms are deprecated! */
+extern size_t PQescapeString(char *to, const char *from, size_t length);
+extern unsigned char *PQescapeBytea(const unsigned char *from, size_t from_length,
+			  size_t *to_length);
+
+
+
+/* === in fe-print.c === */
+
+extern void
+PQprint(FILE *fout,				/* output stream */
+		const PGresult *res,
+		const PQprintOpt *ps);	/* option structure */
+
+/*
+ * really old printing routines
+ */
+extern void
+PQdisplayTuples(const PGresult *res,
+				FILE *fp,		/* where to send the output */
+				int fillAlign,	/* pad the fields with spaces */
+				const char *fieldSep,	/* field separator */
+				int printHeader,	/* display headers? */
+				int quiet);
+
+extern void
+PQprintTuples(const PGresult *res,
+			  FILE *fout,		/* output stream */
+			  int printAttName, /* print attribute names */
+			  int terseOutput,	/* delimiter bars */
+			  int width);		/* width of column, if 0, use variable width */
+
+
+/* === in fe-lobj.c === */
+
+/* Large-object access routines */
+extern int	lo_open(PGconn *conn, Oid lobjId, int mode);
+extern int	lo_close(PGconn *conn, int fd);
+extern int	lo_read(PGconn *conn, int fd, char *buf, size_t len);
+extern int	lo_write(PGconn *conn, int fd, const char *buf, size_t len);
+extern int	lo_lseek(PGconn *conn, int fd, int offset, int whence);
+extern Oid	lo_creat(PGconn *conn, int mode);
+extern Oid	lo_create(PGconn *conn, Oid lobjId);
+extern int	lo_tell(PGconn *conn, int fd);
+extern int	lo_truncate(PGconn *conn, int fd, size_t len);
+extern int	lo_unlink(PGconn *conn, Oid lobjId);
+extern Oid	lo_import(PGconn *conn, const char *filename);
+extern Oid	lo_import_with_oid(PGconn *conn, const char *filename, Oid lobjId);
+extern int	lo_export(PGconn *conn, Oid lobjId, const char *filename);
+
+/* === in fe-misc.c === */
+
+/* Get the version of the libpq library in use */
+extern int	PQlibVersion(void);
+
+/* Determine length of multibyte encoded char at *s */
+extern int	PQmblen(const char *s, int encoding);
+
+/* Determine display length of multibyte encoded char at *s */
+extern int	PQdsplen(const char *s, int encoding);
+
+/* Get encoding id from environment variable PGCLIENTENCODING */
+extern int	PQenv2encoding(void);
+
+/* === in fe-auth.c === */
+
+extern char *PQencryptPassword(const char *passwd, const char *user);
+
+/* === in encnames.c === */
+
+extern int	pg_char_to_encoding(const char *name);
+extern const char *pg_encoding_to_char(int encoding);
+extern int	pg_valid_server_encoding_id(int encoding);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif   /* LIBPQ_FE_H */
diff --git a/Frameworks/PostgresKit/Libs/libpq/include/postgres_ext.h b/Frameworks/PostgresKit/Libs/libpq/include/postgres_ext.h
new file mode 100644
index 00000000..b6ebb7aa
--- /dev/null
+++ b/Frameworks/PostgresKit/Libs/libpq/include/postgres_ext.h
@@ -0,0 +1,59 @@
+/*-------------------------------------------------------------------------
+ *
+ * postgres_ext.h
+ *
+ *	   This file contains declarations of things that are visible everywhere
+ *	in PostgreSQL *and* are visible to clients of frontend interface libraries.
+ *	For example, the Oid type is part of the API of libpq and other libraries.
+ *
+ *	   Declarations which are specific to a particular interface should
+ *	go in the header file for that interface (such as libpq-fe.h).	This
+ *	file is only for fundamental Postgres declarations.
+ *
+ *	   User-written C functions don't count as "external to Postgres."
+ *	Those function much as local modifications to the backend itself, and
+ *	use header files that are otherwise internal to Postgres to interface
+ *	with the backend.
+ *
+ * src/include/postgres_ext.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef POSTGRES_EXT_H
+#define POSTGRES_EXT_H
+
+/*
+ * Object ID is a fundamental type in Postgres.
+ */
+typedef unsigned int Oid;
+
+#ifdef __cplusplus
+#define InvalidOid		(Oid(0))
+#else
+#define InvalidOid		((Oid) 0)
+#endif
+
+#define OID_MAX  UINT_MAX
+/* you will need to include <limits.h> to use the above #define */
+
+
+/*
+ * Identifiers of error message fields.  Kept here to keep common
+ * between frontend and backend, and also to export them to libpq
+ * applications.
+ */
+#define PG_DIAG_SEVERITY		'S'
+#define PG_DIAG_SQLSTATE		'C'
+#define PG_DIAG_MESSAGE_PRIMARY 'M'
+#define PG_DIAG_MESSAGE_DETAIL	'D'
+#define PG_DIAG_MESSAGE_HINT	'H'
+#define PG_DIAG_STATEMENT_POSITION 'P'
+#define PG_DIAG_INTERNAL_POSITION 'p'
+#define PG_DIAG_INTERNAL_QUERY	'q'
+#define PG_DIAG_CONTEXT			'W'
+#define PG_DIAG_SOURCE_FILE		'F'
+#define PG_DIAG_SOURCE_LINE		'L'
+#define PG_DIAG_SOURCE_FUNCTION 'R'
+
+#endif