misc.c

Go to the documentation of this file.

/* src/interfaces/ecpg/ecpglib/misc.c */
 
#define POSTGRES_ECPG_INTERNAL
#include "postgres_fe.h"
 
#include <limits.h>
#include <unistd.h>
 
#include "ecpg-pthread-win32.h"
#include "ecpgerrno.h"
#include "ecpglib.h"
#include "ecpglib_extern.h"
#include "ecpgtype.h"
#include "pg_config_paths.h"
#include "pgtypes_date.h"
#include "pgtypes_interval.h"
#include "pgtypes_numeric.h"
#include "pgtypes_timestamp.h"
#include "sqlca.h"
 
#ifndef LONG_LONG_MIN
#ifdef LLONG_MIN
#define LONG_LONG_MIN LLONG_MIN
#else
#define LONG_LONG_MIN LONGLONG_MIN
#endif                          /* LLONG_MIN */
#endif                          /* LONG_LONG_MIN */
 
bool        ecpg_internal_regression_mode = false;
 
static struct sqlca_t sqlca_init =
{
    {
        'S', 'Q', 'L', 'C', 'A', ' ', ' ', ' '
    },
    sizeof(struct sqlca_t),
    0,
    {
        0,
        {
            0
        }
    },
    {
        'N', 'O', 'T', ' ', 'S', 'E', 'T', ' '
    },
    {
        0, 0, 0, 0, 0, 0
    },
    {
        0, 0, 0, 0, 0, 0, 0, 0
    },
    {
        '0', '0', '0', '0', '0'
    }
};
 
static pthread_key_t sqlca_key;
static pthread_once_t sqlca_key_once = PTHREAD_ONCE_INIT;
 
static pthread_mutex_t debug_mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t debug_init_mutex = PTHREAD_MUTEX_INITIALIZER;
static volatile int simple_debug = 0;
static FILE *debugstream = NULL;
 
void
ecpg_init_sqlca(struct sqlca_t *sqlca)
{
    memcpy(sqlca, &sqlca_init, sizeof(struct sqlca_t));
}
 
bool
ecpg_init(const struct connection *con, const char *connection_name, const int lineno)
{
    struct sqlca_t *sqlca = ECPGget_sqlca();
 
    if (sqlca == NULL)
    {
        ecpg_raise(lineno, ECPG_OUT_OF_MEMORY, ECPG_SQLSTATE_ECPG_OUT_OF_MEMORY,
                   NULL);
        return false;
    }
 
    ecpg_init_sqlca(sqlca);
    if (con == NULL)
    {
        ecpg_raise(lineno, ECPG_NO_CONN, ECPG_SQLSTATE_CONNECTION_DOES_NOT_EXIST,
                   connection_name ? connection_name : ecpg_gettext("NULL"));
        return false;
    }
 
    return true;
}
 
static void
ecpg_sqlca_key_destructor(void *arg)
{
    free(arg);                  /* sqlca structure allocated in ECPGget_sqlca */
}
 
static void
ecpg_sqlca_key_init(void)
{
    pthread_key_create(&sqlca_key, ecpg_sqlca_key_destructor);
}
 
struct sqlca_t *
ECPGget_sqlca(void)
{
    struct sqlca_t *sqlca;
 
    pthread_once(&sqlca_key_once, ecpg_sqlca_key_init);
 
    sqlca = pthread_getspecific(sqlca_key);
    if (sqlca == NULL)
    {
        sqlca = malloc(sizeof(struct sqlca_t));
        if (sqlca == NULL)
            return NULL;
        ecpg_init_sqlca(sqlca);
        pthread_setspecific(sqlca_key, sqlca);
    }
    return sqlca;
}
 
bool
ECPGstatus(int lineno, const char *connection_name)
{
    struct connection *con = ecpg_get_connection(connection_name);
 
    if (!ecpg_init(con, connection_name, lineno))
        return false;
 
    /* are we connected? */
    if (con->connection == NULL)
    {
        ecpg_raise(lineno, ECPG_NOT_CONN, ECPG_SQLSTATE_ECPG_INTERNAL_ERROR, con->name);
        return false;
    }
 
    return true;
}
 
PGTransactionStatusType
ECPGtransactionStatus(const char *connection_name)
{
    const struct connection *con;
 
    con = ecpg_get_connection(connection_name);
    if (con == NULL)
    {
        /* transaction status is unknown */
        return PQTRANS_UNKNOWN;
    }
 
    return PQtransactionStatus(con->connection);
}
 
bool
ECPGtrans(int lineno, const char *connection_name, const char *transaction)
{
    PGresult   *res;
    struct connection *con = ecpg_get_connection(connection_name);
 
    if (!ecpg_init(con, connection_name, lineno))
        return false;
 
    ecpg_log("ECPGtrans on line %d: action \"%s\"; connection \"%s\"\n", lineno, transaction, con ? con->name : "null");
 
    /* if we have no connection we just simulate the command */
    if (con && con->connection)
    {
        /*
         * If we got a transaction command but have no open transaction, we
         * have to start one, unless we are in autocommit, where the
         * developers have to take care themselves. However, if the command is
         * a begin statement, we just execute it once. And if the command is
         * commit or rollback prepared, we don't execute it.
         */
        if (PQtransactionStatus(con->connection) == PQTRANS_IDLE &&
            !con->autocommit &&
            strncmp(transaction, "begin", 5) != 0 &&
            strncmp(transaction, "start", 5) != 0 &&
            strncmp(transaction, "commit prepared", 15) != 0 &&
            strncmp(transaction, "rollback prepared", 17) != 0)
        {
            res = PQexec(con->connection, "begin transaction");
            if (!ecpg_check_PQresult(res, lineno, con->connection, ECPG_COMPAT_PGSQL))
                return false;
            PQclear(res);
        }
 
        res = PQexec(con->connection, transaction);
        if (!ecpg_check_PQresult(res, lineno, con->connection, ECPG_COMPAT_PGSQL))
            return false;
        PQclear(res);
    }
 
    return true;
}
 
 
void
ECPGdebug(int n, FILE *dbgs)
{
    /* Interlock against concurrent executions of ECPGdebug() */
    pthread_mutex_lock(&debug_init_mutex);
 
    /* Prevent ecpg_log() from printing while we change settings */
    pthread_mutex_lock(&debug_mutex);
 
    if (n > 100)
    {
        ecpg_internal_regression_mode = true;
        simple_debug = n - 100;
    }
    else
        simple_debug = n;
 
    debugstream = dbgs;
 
    /* We must release debug_mutex before invoking ecpg_log() ... */
    pthread_mutex_unlock(&debug_mutex);
 
    /* ... but keep holding debug_init_mutex to avoid racy printout */
    ecpg_log("ECPGdebug: set to %d\n", simple_debug);
 
    pthread_mutex_unlock(&debug_init_mutex);
}
 
void
ecpg_log(const char *format,...)
{
    va_list     ap;
    const char *intl_format;
    int         bufsize;
    char       *fmt;
    struct sqlca_t *sqlca;
 
    /*
     * For performance reasons, inspect simple_debug without taking the mutex.
     * This could be problematic if fetching an int isn't atomic, but we
     * assume that it is in many other places too.
     */
    if (!simple_debug)
        return;
 
    /* localize the error message string */
    intl_format = ecpg_gettext(format);
 
    /*
     * Insert PID into the format, unless ecpg_internal_regression_mode is set
     * (regression tests want unchanging output).
     */
    bufsize = strlen(intl_format) + 100;
    fmt = (char *) malloc(bufsize);
    if (fmt == NULL)
        return;
 
    if (ecpg_internal_regression_mode)
        snprintf(fmt, bufsize, "[NO_PID]: %s", intl_format);
    else
        snprintf(fmt, bufsize, "[%d]: %s", (int) getpid(), intl_format);
 
    sqlca = ECPGget_sqlca();
 
    pthread_mutex_lock(&debug_mutex);
 
    /* Now that we hold the mutex, recheck simple_debug */
    if (simple_debug)
    {
        va_start(ap, format);
        vfprintf(debugstream, fmt, ap);
        va_end(ap);
 
        /* dump out internal sqlca variables */
        if (ecpg_internal_regression_mode && sqlca != NULL)
        {
            fprintf(debugstream, "[NO_PID]: sqlca: code: %ld, state: %s\n",
                    sqlca->sqlcode, sqlca->sqlstate);
        }
 
        fflush(debugstream);
    }
 
    pthread_mutex_unlock(&debug_mutex);
 
    free(fmt);
}
 
void
ECPGset_noind_null(enum ECPGttype type, void *ptr)
{
    switch (type)
    {
        case ECPGt_char:
        case ECPGt_unsigned_char:
        case ECPGt_string:
            *((char *) ptr) = '\0';
            break;
        case ECPGt_short:
        case ECPGt_unsigned_short:
            *((short int *) ptr) = SHRT_MIN;
            break;
        case ECPGt_int:
        case ECPGt_unsigned_int:
            *((int *) ptr) = INT_MIN;
            break;
        case ECPGt_long:
        case ECPGt_unsigned_long:
        case ECPGt_date:
            *((long *) ptr) = LONG_MIN;
            break;
        case ECPGt_long_long:
        case ECPGt_unsigned_long_long:
            *((long long *) ptr) = LONG_LONG_MIN;
            break;
        case ECPGt_float:
            memset(ptr, 0xff, sizeof(float));
            break;
        case ECPGt_double:
            memset(ptr, 0xff, sizeof(double));
            break;
        case ECPGt_varchar:
            *(((struct ECPGgeneric_varchar *) ptr)->arr) = 0x00;
            ((struct ECPGgeneric_varchar *) ptr)->len = 0;
            break;
        case ECPGt_bytea:
            ((struct ECPGgeneric_bytea *) ptr)->len = 0;
            break;
        case ECPGt_decimal:
            memset(ptr, 0, sizeof(decimal));
            ((decimal *) ptr)->sign = NUMERIC_NULL;
            break;
        case ECPGt_numeric:
            memset(ptr, 0, sizeof(numeric));
            ((numeric *) ptr)->sign = NUMERIC_NULL;
            break;
        case ECPGt_interval:
            memset(ptr, 0xff, sizeof(interval));
            break;
        case ECPGt_timestamp:
            memset(ptr, 0xff, sizeof(timestamp));
            break;
        default:
            break;
    }
}
 
static bool
_check(const unsigned char *ptr, int length)
{
    for (length--; length >= 0; length--)
        if (ptr[length] != 0xff)
            return false;
 
    return true;
}
 
bool
ECPGis_noind_null(enum ECPGttype type, const void *ptr)
{
    switch (type)
    {
        case ECPGt_char:
        case ECPGt_unsigned_char:
        case ECPGt_string:
            if (*((const char *) ptr) == '\0')
                return true;
            break;
        case ECPGt_short:
        case ECPGt_unsigned_short:
            if (*((const short int *) ptr) == SHRT_MIN)
                return true;
            break;
        case ECPGt_int:
        case ECPGt_unsigned_int:
            if (*((const int *) ptr) == INT_MIN)
                return true;
            break;
        case ECPGt_long:
        case ECPGt_unsigned_long:
        case ECPGt_date:
            if (*((const long *) ptr) == LONG_MIN)
                return true;
            break;
        case ECPGt_long_long:
        case ECPGt_unsigned_long_long:
            if (*((const long long *) ptr) == LONG_LONG_MIN)
                return true;
            break;
        case ECPGt_float:
            return _check(ptr, sizeof(float));
            break;
        case ECPGt_double:
            return _check(ptr, sizeof(double));
            break;
        case ECPGt_varchar:
            if (*(((const struct ECPGgeneric_varchar *) ptr)->arr) == 0x00)
                return true;
            break;
        case ECPGt_bytea:
            if (((const struct ECPGgeneric_bytea *) ptr)->len == 0)
                return true;
            break;
        case ECPGt_decimal:
            if (((const decimal *) ptr)->sign == NUMERIC_NULL)
                return true;
            break;
        case ECPGt_numeric:
            if (((const numeric *) ptr)->sign == NUMERIC_NULL)
                return true;
            break;
        case ECPGt_interval:
            return _check(ptr, sizeof(interval));
            break;
        case ECPGt_timestamp:
            return _check(ptr, sizeof(timestamp));
            break;
        default:
            break;
    }
 
    return false;
}
 
#ifdef WIN32
 
int
pthread_mutex_init(pthread_mutex_t *mp, void *attr)
{
    mp->initstate = 0;
    return 0;
}
 
int
pthread_mutex_lock(pthread_mutex_t *mp)
{
    /* Initialize the csection if not already done */
    if (mp->initstate != 1)
    {
        LONG        istate;
 
        while ((istate = InterlockedExchange(&mp->initstate, 2)) == 2)
            Sleep(0);           /* wait, another thread is doing this */
        if (istate != 1)
            InitializeCriticalSection(&mp->csection);
        InterlockedExchange(&mp->initstate, 1);
    }
    EnterCriticalSection(&mp->csection);
    return 0;
}
 
int
pthread_mutex_unlock(pthread_mutex_t *mp)
{
    if (mp->initstate != 1)
        return EINVAL;
    LeaveCriticalSection(&mp->csection);
    return 0;
}
 
static pthread_mutex_t win32_pthread_once_lock = PTHREAD_MUTEX_INITIALIZER;
 
void
win32_pthread_once(volatile pthread_once_t *once, void (*fn) (void))
{
    if (!*once)
    {
        pthread_mutex_lock(&win32_pthread_once_lock);
        if (!*once)
        {
            fn();
            *once = true;
        }
        pthread_mutex_unlock(&win32_pthread_once_lock);
    }
}
#endif                          /* WIN32 */
 
#ifdef ENABLE_NLS
 
char *
ecpg_gettext(const char *msgid)
{
    /*
     * At least on Windows, there are gettext implementations that fail if
     * multiple threads call bindtextdomain() concurrently.  Use a mutex and
     * flag variable to ensure that we call it just once per process.  It is
     * not known that similar bugs exist on non-Windows platforms, but we
     * might as well do it the same way everywhere.
     */
    static volatile bool already_bound = false;
    static pthread_mutex_t binddomain_mutex = PTHREAD_MUTEX_INITIALIZER;
 
    if (!already_bound)
    {
        /* dgettext() preserves errno, but bindtextdomain() doesn't */
#ifdef WIN32
        int         save_errno = GetLastError();
#else
        int         save_errno = errno;
#endif
 
        (void) pthread_mutex_lock(&binddomain_mutex);
 
        if (!already_bound)
        {
            const char *ldir;
 
            /*
             * No relocatable lookup here because the calling executable could
             * be anywhere
             */
            ldir = getenv("PGLOCALEDIR");
            if (!ldir)
                ldir = LOCALEDIR;
            bindtextdomain(PG_TEXTDOMAIN("ecpglib"), ldir);
            already_bound = true;
        }
 
        (void) pthread_mutex_unlock(&binddomain_mutex);
 
#ifdef WIN32
        SetLastError(save_errno);
#else
        errno = save_errno;
#endif
    }
 
    return dgettext(PG_TEXTDOMAIN("ecpglib"), msgid);
}
#endif                          /* ENABLE_NLS */
 
struct var_list *ivlist = NULL;
 
void
ECPGset_var(int number, void *pointer, int lineno)
{
    struct var_list *ptr;
 
    struct sqlca_t *sqlca = ECPGget_sqlca();
 
    if (sqlca == NULL)
    {
        ecpg_raise(lineno, ECPG_OUT_OF_MEMORY,
                   ECPG_SQLSTATE_ECPG_OUT_OF_MEMORY, NULL);
        return;
    }
 
    ecpg_init_sqlca(sqlca);
 
    for (ptr = ivlist; ptr != NULL; ptr = ptr->next)
    {
        if (ptr->number == number)
        {
            /* already known => just change pointer value */
            ptr->pointer = pointer;
            return;
        }
    }
 
    /* a new one has to be added */
    ptr = (struct var_list *) calloc(1L, sizeof(struct var_list));
    if (!ptr)
    {
        sqlca = ECPGget_sqlca();
 
        if (sqlca == NULL)
        {
            ecpg_raise(lineno, ECPG_OUT_OF_MEMORY,
                       ECPG_SQLSTATE_ECPG_OUT_OF_MEMORY, NULL);
            return;
        }
 
        sqlca->sqlcode = ECPG_OUT_OF_MEMORY;
        strncpy(sqlca->sqlstate, "YE001", sizeof(sqlca->sqlstate));
        snprintf(sqlca->sqlerrm.sqlerrmc, sizeof(sqlca->sqlerrm.sqlerrmc), "out of memory on line %d", lineno);
        sqlca->sqlerrm.sqlerrml = strlen(sqlca->sqlerrm.sqlerrmc);
        /* free all memory we have allocated for the user */
        ECPGfree_auto_mem();
    }
    else
    {
        ptr->number = number;
        ptr->pointer = pointer;
        ptr->next = ivlist;
        ivlist = ptr;
    }
}
 
void *
ECPGget_var(int number)
{
    struct var_list *ptr;
 
    for (ptr = ivlist; ptr != NULL && ptr->number != number; ptr = ptr->next);
    return (ptr) ? ptr->pointer : NULL;
}