os_rw.c

Go to the documentation of this file.

/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1997, 1998, 1999, 2000
 *      Sleepycat Software.  All rights reserved.
 */

#include "config.h"

#ifndef lint
static const char revid[] = "$Id: os__rw_8c-source.html,v 1.1 2008/06/08 10:21:29 sebdiaz Exp $";
#endif /* not lint */

#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>

#include <string.h>
#include <unistd.h>
#endif

#include "db_int.h"
#include "os_jump.h"

/*
 * CDB___os_io --
 *      Do an I/O.
 *
 * PUBLIC: int CDB___os_io __P((DB_ENV *, DB_IO *, int, size_t *));
 */
int
CDB___os_io(dbenv, db_iop, op, niop)
        DB_ENV *dbenv;
        DB_IO *db_iop;
        int op;
        size_t *niop;
{
        int ret;

#if defined(HAVE_PREAD) && defined(HAVE_PWRITE)
        switch (op) {
        case DB_IO_READ:
                if (CDB___db_jump.j_read != NULL)
                        goto slow;
                *niop = pread(db_iop->fhp->fd, db_iop->buf,
                    db_iop->bytes, (off_t)db_iop->pgno * db_iop->pagesize);
                break;
        case DB_IO_WRITE:
                if (CDB___db_jump.j_write != NULL)
                        goto slow;
                *niop = pwrite(db_iop->fhp->fd, db_iop->buf,
                    db_iop->bytes, (off_t)db_iop->pgno * db_iop->pagesize);
                break;
        }
        if (*niop == (size_t)db_iop->bytes)
                return (0);
slow:
#endif
        MUTEX_THREAD_LOCK(db_iop->mutexp);

        if ((ret = CDB___os_seek(dbenv, db_iop->fhp,
            db_iop->pagesize, db_iop->pgno, 0, 0, DB_OS_SEEK_SET)) != 0)
                goto err;
        switch (op) {
        case DB_IO_READ:
                ret = CDB___os_read(dbenv,
                    db_iop->fhp, db_iop->buf, db_iop->bytes, niop);
                break;
        case DB_IO_WRITE:
                ret = CDB___os_write(dbenv,
                    db_iop->fhp, db_iop->buf, db_iop->bytes, niop);
                break;
        }

err:    MUTEX_THREAD_UNLOCK(db_iop->mutexp);

        return (ret);

}

/*
 * CDB___os_read --
 *      Read from a file handle.
 *
 * PUBLIC: int CDB___os_read __P((DB_ENV *, DB_FH *, void *, size_t, size_t *));
 */
int
CDB___os_read(dbenv, fhp, addr, len, nrp)
        DB_ENV *dbenv;
        DB_FH *fhp;
        void *addr;
        size_t len;
        size_t *nrp;
{
        size_t offset;
        ssize_t nr;
        int ret;
        u_int8_t *taddr;

        for (taddr = addr,
            offset = 0; offset < len; taddr += nr, offset += nr) {
                if ((nr = CDB___db_jump.j_read != NULL ?
                    CDB___db_jump.j_read(fhp->fd, taddr, len - offset) :
                    read(fhp->fd, taddr, len - offset)) < 0) {
                        ret = CDB___os_get_errno();
                        CDB___db_err(dbenv, "read: 0x%x, %lu: %s", taddr,
                            (u_long)len-offset, strerror(ret));
                        return (ret);
                }
                if (nr == 0)
                        break;
        }
        *nrp = taddr - (u_int8_t *)addr;
        return (0);
}

/*
 * CDB___os_write --
 *      Write to a file handle.
 *
 * PUBLIC: int CDB___os_write __P((DB_ENV *, DB_FH *, void *, size_t, size_t *));
 */
int
CDB___os_write(dbenv, fhp, addr, len, nwp)
        DB_ENV *dbenv;
        DB_FH *fhp;
        void *addr;
        size_t len;
        size_t *nwp;
{
        size_t offset;
        ssize_t nw;
        int ret;
        u_int8_t *taddr;

        for (taddr = addr,
            offset = 0; offset < len; taddr += nw, offset += nw)
                if ((nw = CDB___db_jump.j_write != NULL ?
                    CDB___db_jump.j_write(fhp->fd, taddr, len - offset) :
                    write(fhp->fd, taddr, len - offset)) < 0){
                        ret = CDB___os_get_errno();
                        CDB___db_err(dbenv, "write: 0x%x, %lu: %s", taddr,
                            (u_long)len-offset, strerror(ret));
                        return (ret);
                }
        *nwp = len;
        return (0);
}

---