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

#include "config.h"

#ifndef lint
static const char sccsid[] = "@(#)log_archive.c 10.44 (Sleepycat) 10/9/98";
#endif /* not lint */

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

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

#include "db_int.h"
#include "db_dispatch.h"
#include "shqueue.h"
#include "log.h"
#include "common_ext.h"
#include "clib_ext.h"                   /* XXX: needed for getcwd. */

static int __absname __P((char *, char *, char **));
static int __build_data __P((DB_LOG *, char *, char ***, void *(*)(size_t)));
static int __cmpfunc __P((const void *, const void *));
static int __usermem __P((char ***, void *(*)(size_t)));

/*
 * log_archive --
 *      Supporting function for db_archive(1).
 */
int
log_archive(dblp, listp, flags, db_malloc)
        DB_LOG *dblp;
        char ***listp;
        u_int32_t flags;
        void *(*db_malloc) __P((size_t));
{
        DBT rec;
        DB_LSN stable_lsn;
        u_int32_t fnum;
        int array_size, n, ret;
        char **array, **arrayp, *name, *p, *pref, buf[MAXPATHLEN];

        name = NULL;
        COMPQUIET(fnum, 0);

        LOG_PANIC_CHECK(dblp);

#define OKFLAGS (DB_ARCH_ABS | DB_ARCH_DATA | DB_ARCH_LOG)
        if (flags != 0) {
                if ((ret =
                    __db_fchk(dblp->dbenv, "log_archive", flags, OKFLAGS)) != 0)
                        return (ret);
                if ((ret =
                    __db_fcchk(dblp->dbenv,
                        "log_archive", flags, DB_ARCH_DATA, DB_ARCH_LOG)) != 0)
                        return (ret);
        }

        /*
         * Get the absolute pathname of the current directory.  It would
         * be nice to get the shortest pathname of the database directory,
         * but that's just not possible.
         */
        if (LF_ISSET(DB_ARCH_ABS)) {
                errno = 0;
                if ((pref = getcwd(buf, sizeof(buf))) == NULL)
                        return (errno == 0 ? ENOMEM : errno);
        } else
                pref = NULL;

        switch (LF_ISSET(~DB_ARCH_ABS)) {
        case DB_ARCH_DATA:
                return (__build_data(dblp, pref, listp, db_malloc));
        case DB_ARCH_LOG:
                memset(&rec, 0, sizeof(rec));
                if (F_ISSET(dblp, DB_AM_THREAD))
                        F_SET(&rec, DB_DBT_MALLOC);
                if ((ret = log_get(dblp, &stable_lsn, &rec, DB_LAST)) != 0)
                        return (ret);
                if (F_ISSET(dblp, DB_AM_THREAD))
                        __os_free(rec.data, rec.size);
                fnum = stable_lsn.file;
                break;
        case 0:
                if ((ret = __log_findckp(dblp, &stable_lsn)) != 0) {
                        /*
                         * A return of DB_NOTFOUND means that we didn't find
                         * any records in the log (so we are not going to be
                         * deleting any log files).
                         */
                        if (ret != DB_NOTFOUND)
                                return (ret);
                        *listp = NULL;
                        return (0);
                }
                /* Remove any log files before the last stable LSN. */
                fnum = stable_lsn.file - 1;
                break;
        }

#define LIST_INCREMENT  64
        /* Get some initial space. */
        array_size = 10;
        if ((ret = __os_malloc(sizeof(char *) * array_size, NULL, &array)) != 0)
                return (ret);
        array[0] = NULL;

        /* Build an array of the file names. */
        for (n = 0; fnum > 0; --fnum) {
                if ((ret = __log_name(dblp, fnum, &name, NULL, 0)) != 0)
                        goto err;
                if (__os_exists(name, NULL) != 0) {
                        __os_freestr(name);
                        name = NULL;
                        break;
                }

                if (n >= array_size - 1) {
                        array_size += LIST_INCREMENT;
                        if ((ret = __os_realloc(&array,
                            sizeof(char *) * array_size)) != 0)
                                goto err;
                }

                if (LF_ISSET(DB_ARCH_ABS)) {
                        if ((ret = __absname(pref, name, &array[n])) != 0)
                                goto err;
                        __os_freestr(name);
                } else if ((p = __db_rpath(name)) != NULL) {
                        if ((ret = __os_strdup(p + 1, &array[n])) != 0)
                                goto err;
                        __os_freestr(name);
                } else
                        array[n] = name;

                name = NULL;
                array[++n] = NULL;
        }

        /* If there's nothing to return, we're done. */
        if (n == 0) {
                *listp = NULL;
                ret = 0;
                goto err;
        }

        /* Sort the list. */
        qsort(array, (size_t)n, sizeof(char *), __cmpfunc);

        /* Rework the memory. */
        if ((ret = __usermem(&array, db_malloc)) != 0)
                goto err;

        *listp = array;
        return (0);

err:    if (array != NULL) {
                for (arrayp = array; *arrayp != NULL; ++arrayp)
                        __os_freestr(*arrayp);
                __os_free(array, sizeof(char *) * array_size);
        }
        if (name != NULL)
                __os_freestr(name);
        return (ret);
}

/*
 * __build_data --
 *      Build a list of datafiles for return.
 */
static int
__build_data(dblp, pref, listp, db_malloc)
        DB_LOG *dblp;
        char *pref, ***listp;
        void *(*db_malloc) __P((size_t));
{
        DBT rec;
        DB_LSN lsn;
        __log_register_args *argp;
        u_int32_t rectype;
        int array_size, last, n, nxt, ret;
        char **array, **arrayp, *p, *real_name;

        /* Get some initial space. */
        array_size = 10;
        if ((ret = __os_malloc(sizeof(char *) * array_size, NULL, &array)) != 0)
                return (ret);
        array[0] = NULL;

        memset(&rec, 0, sizeof(rec));
        if (F_ISSET(dblp, DB_AM_THREAD))
                F_SET(&rec, DB_DBT_MALLOC);
        for (n = 0, ret = log_get(dblp, &lsn, &rec, DB_FIRST);
            ret == 0; ret = log_get(dblp, &lsn, &rec, DB_NEXT)) {
                if (rec.size < sizeof(rectype)) {
                        ret = EINVAL;
                        __db_err(dblp->dbenv, "log_archive: bad log record");
                        goto lg_free;
                }

                memcpy(&rectype, rec.data, sizeof(rectype));
                if (rectype != DB_log_register) {
                        if (F_ISSET(dblp, DB_AM_THREAD)) {
                                __os_free(rec.data, rec.size);
                                rec.data = NULL;
                        }
                        continue;
                }
                if ((ret = __log_register_read(rec.data, &argp)) != 0) {
                        ret = EINVAL;
                        __db_err(dblp->dbenv,
                            "log_archive: unable to read log record");
                        goto lg_free;
                }

                if (n >= array_size - 1) {
                        array_size += LIST_INCREMENT;
                        if ((ret = __os_realloc(&array,
                            sizeof(char *) * array_size)) != 0)
                                goto lg_free;
                }

                if ((ret = __os_strdup(argp->name.data, &array[n])) != 0) {
lg_free:                if (F_ISSET(&rec, DB_DBT_MALLOC) && rec.data != NULL)
                                __os_free(rec.data, rec.size);
                        goto err1;
                }

                array[++n] = NULL;
                __os_free(argp, 0);

                if (F_ISSET(dblp, DB_AM_THREAD)) {
                        __os_free(rec.data, rec.size);
                        rec.data = NULL;
                }
        }

        /* If there's nothing to return, we're done. */
        if (n == 0) {
                ret = 0;
                *listp = NULL;
                goto err1;
        }

        /* Sort the list. */
        qsort(array, (size_t)n, sizeof(char *), __cmpfunc);

        /*
         * Build the real pathnames, discarding nonexistent files and
         * duplicates.
         */
        for (last = nxt = 0; nxt < n;) {
                /*
                 * Discard duplicates.  Last is the next slot we're going
                 * to return to the user, nxt is the next slot that we're
                 * going to consider.
                 */
                if (last != nxt) {
                        array[last] = array[nxt];
                        array[nxt] = NULL;
                }
                for (++nxt; nxt < n &&
                    strcmp(array[last], array[nxt]) == 0; ++nxt) {
                        __os_freestr(array[nxt]);
                        array[nxt] = NULL;
                }

                /* Get the real name. */
                if ((ret = __db_appname(dblp->dbenv,
                    DB_APP_DATA, NULL, array[last], 0, NULL, &real_name)) != 0)
                        goto err2;

                /* If the file doesn't exist, ignore it. */
                if (__os_exists(real_name, NULL) != 0) {
                        __os_freestr(real_name);
                        __os_freestr(array[last]);
                        array[last] = NULL;
                        continue;
                }

                /* Rework the name as requested by the user. */
                __os_freestr(array[last]);
                array[last] = NULL;
                if (pref != NULL) {
                        ret = __absname(pref, real_name, &array[last]);
                        __os_freestr(real_name);
                        if (ret != 0)
                                goto err2;
                } else if ((p = __db_rpath(real_name)) != NULL) {
                        ret = __os_strdup(p + 1, &array[last]);
                        __os_freestr(real_name);
                        if (ret != 0)
                                goto err2;
                } else
                        array[last] = real_name;
                ++last;
        }

        /* NULL-terminate the list. */
        array[last] = NULL;

        /* Rework the memory. */
        if ((ret = __usermem(&array, db_malloc)) != 0)
                goto err1;

        *listp = array;
        return (0);

err2:   /*
         * XXX
         * We've possibly inserted NULLs into the array list, so clean up a
         * bit so that the other error processing works.
         */
        if (array != NULL)
                for (; nxt < n; ++nxt)
                        __os_freestr(array[nxt]);
        /* FALLTHROUGH */

err1:   if (array != NULL) {
                for (arrayp = array; *arrayp != NULL; ++arrayp)
                        __os_freestr(*arrayp);
                __os_free(array, array_size * sizeof(char *));
        }
        return (ret);
}

/*
 * __absname --
 *      Return an absolute path name for the file.
 */
static int
__absname(pref, name, newnamep)
        char *pref, *name, **newnamep;
{
        size_t l_pref, l_name;
        int isabspath, ret;
        char *newname;

        l_name = strlen(name);
        isabspath = __os_abspath(name);
        l_pref = isabspath ? 0 : strlen(pref);

        /* Malloc space for concatenating the two. */
        if ((ret = __os_malloc(l_pref + l_name + 2, NULL, &newname)) != 0)
                return (ret);
        *newnamep = newname;

        /* Build the name.  If `name' is an absolute path, ignore any prefix. */
        if (!isabspath) {
                memcpy(newname, pref, l_pref);
                if (strchr(PATH_SEPARATOR, newname[l_pref - 1]) == NULL)
                        newname[l_pref++] = PATH_SEPARATOR[0];
        }
        memcpy(newname + l_pref, name, l_name + 1);

        return (0);
}

/*
 * __usermem --
 *      Create a single chunk of memory that holds the returned information.
 *      If the user has their own malloc routine, use it.
 */
static int
__usermem(listp, db_malloc)
        char ***listp;
        void *(*db_malloc) __P((size_t));
{
        size_t len;
        int ret;
        char **array, **arrayp, **orig, *strp;

        /* Find out how much space we need. */
        for (len = 0, orig = *listp; *orig != NULL; ++orig)
                len += sizeof(char *) + strlen(*orig) + 1;
        len += sizeof(char *);

        /* Allocate it and set up the pointers. */
        if ((ret = __os_malloc(len, db_malloc, &array)) != 0)
                return (ret);

        strp = (char *)(array + (orig - *listp) + 1);

        /* Copy the original information into the new memory. */
        for (orig = *listp, arrayp = array; *orig != NULL; ++orig, ++arrayp) {
                len = strlen(*orig);
                memcpy(strp, *orig, len + 1);
                *arrayp = strp;
                strp += len + 1;

                __os_freestr(*orig);
        }

        /* NULL-terminate the list. */
        *arrayp = NULL;

        __os_free(*listp, 0);
        *listp = array;

        return (0);
}

static int
__cmpfunc(p1, p2)
        const void *p1, *p2;
{
        return (strcmp(*((char * const *)p1), *((char * const *)p2)));
}