rec_open.c File Reference

#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stddef.h>
#include <stdio.h>
#include <unistd.h>
#include "../include/db.h"
#include "recno.h"

Include dependency graph for rec_open.c:

Go to the source code of this file.

Functions
int	__rec_fd (DB *dbp) const
DB *	__rec_open (char *fname, int flags, int mode, const RECNOINFO *openinfo, int dflags) const

Function Documentation

__rec_fd()

int __rec_fd

(

DB *

dbp

)

const

Definition at line 222 of file rec_open.c.

{
    BTREE *t;
 
    t = dbp->internal;
 
    /* Toss any page pinned across calls. */
    if (t->bt_pinned != NULL) {
        mpool_put(t->bt_mp, t->bt_pinned, 0);
        t->bt_pinned = NULL;
    }
 
    /* In-memory database can't have a file descriptor. */
    if (F_ISSET(t, R_INMEM)) {
        errno = ENOENT;
        return (-1);
    }
    return (t->bt_rfd);
}

References _btree::bt_mp, _btree::bt_pinned, _btree::bt_rfd, dbp, errno, F_ISSET, __db::internal, mpool_put(), NULL, and R_INMEM.

Referenced by __rec_open().

__rec_open()

DB * __rec_open	(	char *	fname,
		int	flags,
		int	mode,
		const RECNOINFO *	openinfo,
		int	dflags
	)		const

Definition at line 56 of file rec_open.c.

{
    BTREE *t;
    BTREEINFO btopeninfo;
    DB *dbp;
    PAGE *h;
    struct stat sb;
    int rfd = 0, sverrno;
 
    /* Open the user's file -- if this fails, we're done. */
    if (fname != NULL && (rfd = open(fname, flags, mode)) < 0)
        return (NULL);
 
    /* Create a btree in memory (backed by disk). */
    dbp = NULL;
    if (openinfo) {
        if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT))
            goto einval;
        btopeninfo.flags = 0;
        btopeninfo.cachesize = openinfo->cachesize;
        btopeninfo.maxkeypage = 0;
        btopeninfo.minkeypage = 0;
        btopeninfo.psize = openinfo->psize;
        btopeninfo.compare = NULL;
        btopeninfo.prefix = NULL;
        btopeninfo.lorder = openinfo->lorder;
        dbp = __bt_open(openinfo->bfname,
            O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo, dflags);
    } else
        dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL, dflags);
    if (dbp == NULL)
        goto err;
 
    /*
     * Some fields in the tree structure are recno specific.  Fill them
     * in and make the btree structure look like a recno structure.  We
     * don't change the bt_ovflsize value, it's close enough and slightly
     * bigger.
     */
    t = dbp->internal;
    if (openinfo) {
        if (openinfo->flags & R_FIXEDLEN) {
            F_SET(t, R_FIXLEN);
            t->bt_reclen = openinfo->reclen;
            if (t->bt_reclen == 0)
                goto einval;
        }
        t->bt_bval = openinfo->bval;
    } else
        t->bt_bval = '\n';
 
    F_SET(t, R_RECNO);
    if (fname == NULL)
        F_SET(t, R_EOF | R_INMEM);
    else
        t->bt_rfd = rfd;
 
    if (fname != NULL) {
        /*
         * In 4.4BSD, stat(2) returns true for ISSOCK on pipes.
         * Unfortunately, that's not portable, so we use lseek
         * and check the errno values.
         */
        errno = 0;
        if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) {
            switch (flags & O_ACCMODE) {
            case O_RDONLY:
                F_SET(t, R_RDONLY);
                break;
            default:
                goto einval;
            }
slow:           if ((t->bt_rfp = fdopen(rfd, "r")) == NULL)
                goto err;
            F_SET(t, R_CLOSEFP);
            t->bt_irec =
                F_ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe;
        } else {
            switch (flags & O_ACCMODE) {
            case O_RDONLY:
                F_SET(t, R_RDONLY);
                break;
            case O_RDWR:
                break;
            default:
                goto einval;
            }
 
            if (fstat(rfd, &sb))
                goto err;
            /*
             * Kluge -- we'd like to test to see if the file is too
             * big to mmap.  Since, we don't know what size or type
             * off_t's or size_t's are, what the largest unsigned
             * integral type is, or what random insanity the local
             * C compiler will perpetrate, doing the comparison in
             * a portable way is flatly impossible.  Hope that mmap
             * fails if the file is too large.
             */
            if (sb.st_size == 0)
                F_SET(t, R_EOF);
            else {
#ifdef MMAP_NOT_AVAILABLE
                /*
                 * XXX
                 * Mmap doesn't work correctly on many current
                 * systems.  In particular, it can fail subtly,
                 * with cache coherency problems.  Don't use it
                 * for now.
                 */
                t->bt_msize = sb.st_size;
                if ((t->bt_smap = mmap(NULL, t->bt_msize,
                    PROT_READ, MAP_PRIVATE, rfd,
                    (off_t)0)) == MAP_FAILED
                    goto slow;
                t->bt_cmap = t->bt_smap;
                t->bt_emap = t->bt_smap + sb.st_size;
                t->bt_irec = F_ISSET(t, R_FIXLEN) ?
                    __rec_fmap : __rec_vmap;
                F_SET(t, R_MEMMAPPED);
#else
                goto slow;
#endif
            }
        }
    }
 
    /* Use the recno routines. */
    dbp->close = __rec_close;
    dbp->del = __rec_delete;
    dbp->fd = __rec_fd;
    dbp->get = __rec_get;
    dbp->put = __rec_put;
    dbp->seq = __rec_seq;
    dbp->sync = __rec_sync;
 
    /* If the root page was created, reset the flags. */
    if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL)
        goto err;
    if ((h->flags & P_TYPE) == P_BLEAF) {
        F_CLR(h, P_TYPE);
        F_SET(h, P_RLEAF);
        mpool_put(t->bt_mp, h, MPOOL_DIRTY);
    } else
        mpool_put(t->bt_mp, h, 0);
 
    if (openinfo && openinfo->flags & R_SNAPSHOT &&
        !F_ISSET(t, R_EOF | R_INMEM) &&
        t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR)
                goto err;
    return (dbp);
 
einval: errno = EINVAL;
err:    sverrno = errno;
    if (dbp != NULL)
        (void)__bt_close(dbp);
    if (fname != NULL)
        (void)close(rfd);
    errno = sverrno;
    return (NULL);
}

References __bt_close(), __bt_open(), __rec_close(), __rec_delete(), __rec_fd(), __rec_fmap(), __rec_fpipe(), __rec_get(), __rec_put(), __rec_seq(), __rec_sync(), __rec_vmap(), __rec_vpipe(), RECNOINFO::bfname, _btree::bt_bval, _btree::bt_cmap, _btree::bt_emap, _btree::bt_mp, _btree::bt_msize, _btree::bt_reclen, _btree::bt_rfd, _btree::bt_rfp, _btree::bt_smap, RECNOINFO::bval, BTREEINFO::cachesize, RECNOINFO::cachesize, dbp, errno, F_CLR, F_ISSET, F_SET, _page::flags, BTREEINFO::flags, RECNOINFO::flags, __db::internal, BTREEINFO::lorder, RECNOINFO::lorder, MAX_REC_NUMBER, BTREEINFO::maxkeypage, BTREEINFO::minkeypage, MPOOL_DIRTY, mpool_get(), mpool_put(), NULL, P_BLEAF, P_RLEAF, P_ROOT, P_TYPE, BTREEINFO::psize, RECNOINFO::psize, R_CLOSEFP, R_EOF, R_FIXEDLEN, R_FIXLEN, R_INMEM, R_MEMMAPPED, R_NOKEY, R_RDONLY, R_RECNO, R_SNAPSHOT, RECNOINFO::reclen, and RET_ERROR.

Referenced by dbopen().