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/*-------------------------------------------------------------------------
*
* libpq-fe.h
* This file contains definitions for structures and
* externs for functions used by frontend postgres applications.
*
* Portions Copyright (c) 1996-2020, 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 */
/*
* Although it is okay to add to these lists, values which become unused
* should never be removed, nor should constants be redefined - that would
* break compatibility with existing code.
*/
typedef enum
{
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 */
CONNECTION_CHECK_WRITABLE, /* Check if we could make a writable
* connection. */
CONNECTION_CONSUME, /* Wait for any pending message and consume
* them. */
CONNECTION_GSS_STARTUP, /* Negotiating GSSAPI. */
CONNECTION_CHECK_TARGET /* Check if we have a proper target connection */
} 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 */
PGRES_SINGLE_TUPLE /* single tuple from larger resultset */
} 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 */
PQERRORS_SQLSTATE /* only error severity and SQLSTATE code */
} PGVerbosity;
typedef enum
{
PQSHOW_CONTEXT_NEVER, /* never show CONTEXT field */
PQSHOW_CONTEXT_ERRORS, /* show CONTEXT for errors only (default) */
PQSHOW_CONTEXT_ALWAYS /* always show CONTEXT field */
} PGContextVisibility;
/*
* PGPing - The ordering of this enum should not be altered because the
* values are exposed externally via pg_isready.
*/
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 *const *keywords,
const char *const *values, int expand_dbname);
extern PostgresPollingStatusType PQconnectPoll(PGconn *conn);
/* Synchronous (blocking) */
extern PGconn *PQconnectdb(const char *conninfo);
extern PGconn *PQconnectdbParams(const char *const *keywords,
const char *const *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);
/* return the connection options used by a live connection */
extern PQconninfoOption *PQconninfo(PGconn *conn);
/* free the data structure returned by PQconndefaults() or PQconninfoParse() */
extern void PQconninfoFree(PQconninfoOption *connOptions);
/*
* close the current connection and reestablish 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 *PQhostaddr(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);
/* SSL information functions */
extern int PQsslInUse(PGconn *conn);
extern void *PQsslStruct(PGconn *conn, const char *struct_name);
extern const char *PQsslAttribute(PGconn *conn, const char *attribute_name);
extern const char *const *PQsslAttributeNames(PGconn *conn);
/* 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);
/* Return true if GSSAPI encryption is in use */
extern int PQgssEncInUse(PGconn *conn);
/* Returns GSSAPI context if GSSAPI is in use */
extern void *PQgetgssctx(PGconn *conn);
/* Set verbosity for PQerrorMessage and PQresultErrorMessage */
extern PGVerbosity PQsetErrorVerbosity(PGconn *conn, PGVerbosity verbosity);
/* Set CONTEXT visibility for PQerrorMessage and PQresultErrorMessage */
extern PGContextVisibility PQsetErrorContextVisibility(PGconn *conn,
PGContextVisibility show_context);
/* 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 int PQsetSingleRowMode(PGconn *conn);
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 *const *keywords,
const char *const *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 *PQresultVerboseErrorMessage(const PGresult *res,
PGVerbosity verbosity,
PGContextVisibility show_context);
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 size_t PQresultMemorySize(const PGresult *res);
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 PrintAttNames, /* print attribute names */
int TerseOutput, /* delimiter bars */
int colWidth); /* 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 pg_int64 lo_lseek64(PGconn *conn, int fd, pg_int64 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 pg_int64 lo_tell64(PGconn *conn, int fd);
extern int lo_truncate(PGconn *conn, int fd, size_t len);
extern int lo_truncate64(PGconn *conn, int fd, pg_int64 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);
extern char *PQencryptPasswordConn(PGconn *conn, const char *passwd, const char *user, const char *algorithm);
/* === 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);
/* === in fe-secure-openssl.c === */
/* Support for overriding sslpassword handling with a callback. */
typedef int (*PQsslKeyPassHook_OpenSSL_type) (char *buf, int size, PGconn *conn);
extern PQsslKeyPassHook_OpenSSL_type PQgetSSLKeyPassHook_OpenSSL(void);
extern void PQsetSSLKeyPassHook_OpenSSL(PQsslKeyPassHook_OpenSSL_type hook);
extern int PQdefaultSSLKeyPassHook_OpenSSL(char *buf, int size, PGconn *conn);
#ifdef __cplusplus
}
#endif
#endif /* LIBPQ_FE_H */