diff options
Diffstat (limited to 'db2/btree/bt_recno.c')
| -rw-r--r-- | db2/btree/bt_recno.c | 1195 |
1 files changed, 1195 insertions, 0 deletions
diff --git a/db2/btree/bt_recno.c b/db2/btree/bt_recno.c new file mode 100644 index 0000000000..cd8872a064 --- /dev/null +++ b/db2/btree/bt_recno.c @@ -0,0 +1,1195 @@ +/*- + * See the file LICENSE for redistribution information. + * + * Copyright (c) 1997 + * Sleepycat Software. All rights reserved. + */ + +#include "config.h" + +#ifndef lint +static const char sccsid[] = "@(#)bt_recno.c 10.12 (Sleepycat) 8/25/97"; +#endif /* not lint */ + +#ifndef NO_SYSTEM_INCLUDES +#include <sys/types.h> + +#include <errno.h> +#include <limits.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#endif + +#include "db_int.h" +#include "db_page.h" +#include "btree.h" + +static int __ram_add __P((DB *, db_recno_t *, DBT *, int, int)); +static int __ram_c_close __P((DBC *)); +static int __ram_c_del __P((DBC *, int)); +static int __ram_c_get __P((DBC *, DBT *, DBT *, int)); +static int __ram_c_put __P((DBC *, DBT *, DBT *, int)); +static int __ram_fmap __P((DB *, db_recno_t)); +static int __ram_get __P((DB *, DB_TXN *, DBT *, DBT *, int)); +static int __ram_put __P((DB *, DB_TXN *, DBT *, DBT *, int)); +static int __ram_source __P((DB *, RECNO *, const char *)); +static int __ram_sync __P((DB *, int)); +static int __ram_update __P((DB *, db_recno_t, int)); +static int __ram_vmap __P((DB *, db_recno_t)); +static int __ram_writeback __P((DB *)); + +/* + * If we're renumbering records, then we have to detect in the cursor that a + * record was deleted, and adjust the cursor as necessary. If not renumbering + * records, then we can detect this by looking at the actual record, so we + * ignore the cursor delete flag. + */ +#define CD_SET(dbp, cp) { \ + if (F_ISSET(dbp, DB_RE_RENUMBER)) \ + F_SET(cp, CR_DELETED); \ +} +#define CD_CLR(dbp, cp) { \ + if (F_ISSET(dbp, DB_RE_RENUMBER)) \ + F_CLR(cp, CR_DELETED); \ +} +#define CD_ISSET(dbp, cp) \ + (F_ISSET(dbp, DB_RE_RENUMBER) && F_ISSET(cp, CR_DELETED)) + +/* + * __ram_open -- + * Recno open function. + * + * PUBLIC: int __ram_open __P((DB *, DBTYPE, DB_INFO *)); + */ +int +__ram_open(dbp, type, dbinfo) + DB *dbp; + DBTYPE type; + DB_INFO *dbinfo; +{ + BTREE *t; + RECNO *rp; + int ret; + + ret = 0; + + /* Allocate and initialize the private RECNO structure. */ + if ((rp = (RECNO *)calloc(1, sizeof(*rp))) == NULL) + return (errno); + + if (dbinfo != NULL) { + /* + * If the user specified a source tree, open it and map it in. + * + * !!! + * We don't complain if the user specified transactions or + * threads. It's possible to make it work, but you'd better + * know what you're doing! + */ + if (dbinfo->re_source == NULL) { + rp->re_fd = -1; + F_SET(rp, RECNO_EOF); + } else { + if ((ret = + __ram_source(dbp, rp, dbinfo->re_source)) != 0) + goto err; + } + + /* Copy delimiter, length and padding values. */ + rp->re_delim = + F_ISSET(dbp, DB_RE_DELIMITER) ? dbinfo->re_delim : '\n'; + rp->re_pad = F_ISSET(dbp, DB_RE_PAD) ? dbinfo->re_pad : ' '; + + if (F_ISSET(dbp, DB_RE_FIXEDLEN)) { + if ((rp->re_len = dbinfo->re_len) == 0) { + __db_err(dbp->dbenv, + "record length must be greater than 0"); + ret = EINVAL; + goto err; + } + } else + rp->re_len = 0; + } else { + rp->re_delim = '\n'; + rp->re_pad = ' '; + rp->re_fd = -1; + F_SET(rp, RECNO_EOF); + } + + /* Open the underlying btree. */ + if ((ret = __bam_open(dbp, DB_RECNO, dbinfo)) != 0) + goto err; + + /* Set the routines necessary to make it look like a recno tree. */ + dbp->cursor = __ram_cursor; + dbp->del = __ram_delete; + dbp->get = __ram_get; + dbp->put = __ram_put; + dbp->sync = __ram_sync; + + /* Link in the private recno structure. */ + ((BTREE *)dbp->internal)->bt_recno = rp; + + /* If we're snapshotting an underlying source file, do it now. */ + if (dbinfo != NULL && F_ISSET(dbinfo, DB_SNAPSHOT)) + if ((ret = __ram_snapshot(dbp)) != 0 && ret != DB_NOTFOUND) + goto err; + + return (0); + +err: /* If we mmap'd a source file, discard it. */ + if (rp->re_smap != NULL) + (void)__db_munmap(rp->re_smap, rp->re_msize); + + /* If we opened a source file, discard it. */ + if (rp->re_fd != -1) + (void)__db_close(rp->re_fd); + if (rp->re_source != NULL) + FREES(rp->re_source); + + /* If we allocated room for key/data return, discard it. */ + t = dbp->internal; + if (t->bt_rkey.data != NULL) + free(t->bt_rkey.data); + + FREE(rp, sizeof(*rp)); + + return (ret); +} + +/* + * __ram_cursor -- + * Recno db->cursor function. + * + * PUBLIC: int __ram_cursor __P((DB *, DB_TXN *, DBC **)); + */ +int +__ram_cursor(dbp, txn, dbcp) + DB *dbp; + DB_TXN *txn; + DBC **dbcp; +{ + RCURSOR *cp; + DBC *dbc; + + DEBUG_LWRITE(dbp, txn, "ram_cursor", NULL, NULL, 0); + + if ((dbc = (DBC *)calloc(1, sizeof(DBC))) == NULL) + return (ENOMEM); + if ((cp = (RCURSOR *)calloc(1, sizeof(RCURSOR))) == NULL) { + free(dbc); + return (ENOMEM); + } + + cp->dbc = dbc; + cp->recno = RECNO_OOB; + + dbc->dbp = dbp; + dbc->txn = txn; + dbc->internal = cp; + dbc->c_close = __ram_c_close; + dbc->c_del = __ram_c_del; + dbc->c_get = __ram_c_get; + dbc->c_put = __ram_c_put; + + /* All cursor structures hang off the main DB structure. */ + DB_THREAD_LOCK(dbp); + TAILQ_INSERT_HEAD(&dbp->curs_queue, dbc, links); + DB_THREAD_UNLOCK(dbp); + + *dbcp = dbc; + return (0); +} + +/* + * __ram_get -- + * Recno db->get function. + */ +static int +__ram_get(argdbp, txn, key, data, flags) + DB *argdbp; + DB_TXN *txn; + DBT *key, *data; + int flags; +{ + BTREE *t; + DB *dbp; + PAGE *h; + db_indx_t indx; + db_recno_t recno; + int exact, ret, stack; + + stack = 0; + + DEBUG_LWRITE(argdbp, txn, "ram_get", key, NULL, flags); + + /* Check for invalid flags. */ + if ((ret = __db_getchk(argdbp, key, data, flags)) != 0) + return (ret); + + GETHANDLE(argdbp, txn, &dbp, ret); + t = dbp->internal; + + /* Check the user's record number and fill in as necessary. */ + if ((ret = __ram_getno(dbp, key, &recno, 0)) != 0) + goto done; + + /* Search the tree for the record. */ + if ((ret = __bam_rsearch(dbp, &recno, S_FIND, 1, &exact)) != 0) + goto done; + if (!exact) + return (DB_NOTFOUND); + stack = 1; + + h = t->bt_csp->page; + indx = t->bt_csp->indx; + + /* If the record has already been deleted, we couldn't have found it. */ + if (GET_BKEYDATA(h, indx)->deleted) { + ret = DB_KEYEMPTY; + goto done; + } + + /* Return the data item. */ + ret = __db_ret(dbp, + h, indx, data, &t->bt_rdata.data, &t->bt_rdata.ulen); + ++t->lstat.bt_get; + +done: /* Discard the stack. */ + if (stack) + __bam_stkrel(dbp); + + PUTHANDLE(dbp); + return (ret); +} + +/* + * __ram_put -- + * Recno db->put function. + */ +static int +__ram_put(argdbp, txn, key, data, flags) + DB *argdbp; + DB_TXN *txn; + DBT *key, *data; + int flags; +{ + BTREE *t; + DB *dbp; + db_recno_t recno; + int ret; + + DEBUG_LWRITE(argdbp, txn, "ram_put", key, data, flags); + + /* Check for invalid flags. */ + if ((ret = __db_putchk(argdbp, + key, data, flags, F_ISSET(argdbp, DB_AM_RDONLY), 0)) != 0) + return (ret); + + GETHANDLE(argdbp, txn, &dbp, ret); + + /* + * If we're appending to the tree, make sure we've read in all of + * the backing source file. Otherwise, check the user's record + * number and fill in as necessary. + */ + ret = LF_ISSET(DB_APPEND) ? + __ram_snapshot(dbp) : __ram_getno(dbp, key, &recno, 1); + + /* Add the record. */ + if (ret == 0) + ret = __ram_add(dbp, &recno, data, flags, 0); + + /* If we're appending to the tree, we have to return the record. */ + if (ret == 0 && LF_ISSET(DB_APPEND)) { + t = dbp->internal; + ret = __db_retcopy(key, &recno, sizeof(recno), + &t->bt_rkey.data, &t->bt_rkey.ulen, dbp->db_malloc); + } + + PUTHANDLE(dbp); + return (ret); +} + +/* + * __ram_sync -- + * Recno db->sync function. + */ +static int +__ram_sync(argdbp, flags) + DB *argdbp; + int flags; +{ + DB *dbp; + int ret; + + DEBUG_LWRITE(argdbp, NULL, "ram_sync", NULL, NULL, flags); + + /* Sync the underlying btree. */ + if ((ret = __bam_sync(argdbp, flags)) != 0) + return (ret); + + /* Copy back the backing source file. */ + GETHANDLE(argdbp, NULL, &dbp, ret); + ret = __ram_writeback(dbp); + PUTHANDLE(dbp); + + return (ret); +} + +/* + * __ram_close -- + * Recno db->close function. + * + * PUBLIC: int __ram_close __P((DB *)); + */ +int +__ram_close(argdbp) + DB *argdbp; +{ + RECNO *rp; + + DEBUG_LWRITE(argdbp, NULL, "ram_close", NULL, NULL, 0); + + rp = ((BTREE *)argdbp->internal)->bt_recno; + + /* Close any underlying mmap region. */ + if (rp->re_smap != NULL) + (void)__db_munmap(rp->re_smap, rp->re_msize); + + /* Close any backing source file descriptor. */ + if (rp->re_fd != -1) + (void)__db_close(rp->re_fd); + + /* Free any backing source file name. */ + if (rp->re_source != NULL) + FREES(rp->re_source); + + /* Free allocated memory. */ + FREE(rp, sizeof(RECNO)); + ((BTREE *)argdbp->internal)->bt_recno = NULL; + + /* Close the underlying btree. */ + return (__bam_close(argdbp)); +} + +/* + * __ram_c_close -- + * Recno cursor->close function. + */ +static int +__ram_c_close(dbc) + DBC *dbc; +{ + DB *dbp; + + DEBUG_LWRITE(dbc->dbp, dbc->txn, "ram_c_close", NULL, NULL, 0); + + dbp = dbc->dbp; + + /* Remove the cursor from the queue. */ + DB_THREAD_LOCK(dbp); + TAILQ_REMOVE(&dbp->curs_queue, dbc, links); + DB_THREAD_UNLOCK(dbp); + + /* Discard the structures. */ + FREE(dbc->internal, sizeof(RCURSOR)); + FREE(dbc, sizeof(DBC)); + + return (0); +} + +/* + * __ram_c_del -- + * Recno cursor->c_del function. + */ +static int +__ram_c_del(dbc, flags) + DBC *dbc; + int flags; +{ + DBT key; + RCURSOR *cp; + int ret; + + DEBUG_LWRITE(dbc->dbp, dbc->txn, "ram_c_del", NULL, NULL, flags); + + cp = dbc->internal; + + /* Check for invalid flags. */ + if ((ret = __db_cdelchk(dbc->dbp, flags, + F_ISSET(dbc->dbp, DB_AM_RDONLY), cp->recno != RECNO_OOB)) != 0) + return (ret); + + /* If already deleted, return failure. */ + if (CD_ISSET(dbc->dbp, cp)) + return (DB_KEYEMPTY); + + /* Build a normal delete request. */ + memset(&key, 0, sizeof(key)); + key.data = &cp->recno; + key.size = sizeof(db_recno_t); + if ((ret = __ram_delete(dbc->dbp, dbc->txn, &key, 0)) == 0) + CD_SET(dbc->dbp, cp); + + return (ret); +} + +/* + * __ram_c_get -- + * Recno cursor->c_get function. + */ +static int +__ram_c_get(dbc, key, data, flags) + DBC *dbc; + DBT *key, *data; + int flags; +{ + BTREE *t; + DB *dbp; + RCURSOR *cp, copy; + int ret; + + DEBUG_LREAD(dbc->dbp, dbc->txn, "ram_c_get", + flags == DB_SET || flags == DB_SET_RANGE ? key : NULL, + NULL, flags); + + cp = dbc->internal; + dbp = dbc->dbp; + + /* Check for invalid flags. */ + if ((ret = __db_cgetchk(dbc->dbp, + key, data, flags, cp->recno != RECNO_OOB)) != 0) + return (ret); + + GETHANDLE(dbc->dbp, dbc->txn, &dbp, ret); + t = dbp->internal; + + /* Initialize the cursor for a new retrieval. */ + copy = *cp; + +retry: /* Update the record number. */ + switch (flags) { + case DB_CURRENT: + if (CD_ISSET(dbp, cp)) { + PUTHANDLE(dbp); + return (DB_KEYEMPTY); + } + break; + case DB_NEXT: + if (CD_ISSET(dbp, cp)) + break; + if (cp->recno != RECNO_OOB) { + ++cp->recno; + break; + } + /* FALLTHROUGH */ + case DB_FIRST: + flags = DB_NEXT; + cp->recno = 1; + break; + case DB_PREV: + if (cp->recno != RECNO_OOB) { + if (cp->recno == 1) + return (DB_NOTFOUND); + --cp->recno; + break; + } + /* FALLTHROUGH */ + case DB_LAST: + flags = DB_PREV; + if (((ret = __ram_snapshot(dbp)) != 0) && ret != DB_NOTFOUND) + goto err; + if ((ret = __bam_nrecs(dbp, &cp->recno)) != 0) + goto err; + if (cp->recno == 0) + return (DB_NOTFOUND); + break; + case DB_SET: + case DB_SET_RANGE: + if ((ret = __ram_getno(dbp, key, &cp->recno, 0)) != 0) + goto err; + break; + } + + /* + * Return the key if the user didn't give us one, and then pass it + * into __ram_get(). + */ + if (flags != DB_SET && flags != DB_SET_RANGE && + (ret = __db_retcopy(key, &cp->recno, sizeof(cp->recno), + &t->bt_rkey.data, &t->bt_rkey.ulen, dbp->db_malloc)) != 0) + return (ret); + + /* + * The cursor was reset, so the delete adjustment is no + * longer necessary. + */ + CD_CLR(dbp, cp); + + /* + * Retrieve the record. + * + * Skip any keys that don't really exist. + */ + if ((ret = __ram_get(dbp, dbc->txn, key, data, 0)) != 0) + if (ret == DB_KEYEMPTY && + (flags == DB_NEXT || flags == DB_PREV)) + goto retry; + +err: if (ret != 0) + *cp = copy; + + PUTHANDLE(dbp); + return (ret); +} + +/* + * __ram_c_put -- + * Recno cursor->c_put function. + */ +static int +__ram_c_put(dbc, key, data, flags) + DBC *dbc; + DBT *key, *data; + int flags; +{ + BTREE *t; + RCURSOR *cp, copy; + DB *dbp; + int exact, ret; + void *arg; + + DEBUG_LWRITE(dbc->dbp, dbc->txn, "ram_c_put", NULL, data, flags); + + cp = dbc->internal; + + if ((ret = __db_cputchk(dbc->dbp, key, data, flags, + F_ISSET(dbc->dbp, DB_AM_RDONLY), cp->recno != RECNO_OOB)) != 0) + return (ret); + + GETHANDLE(dbc->dbp, dbc->txn, &dbp, ret); + t = dbp->internal; + + /* Initialize the cursor for a new retrieval. */ + copy = *cp; + + /* + * To split, we need a valid key for the page. Since it's a cursor, + * we have to build one. + * + * The split code discards all short-term locks and stack pages. + */ + if (0) { +split: arg = &cp->recno; + if ((ret = __bam_split(dbp, arg)) != 0) + goto err; + } + + if ((ret = __bam_rsearch(dbp, &cp->recno, S_INSERT, 1, &exact)) != 0) + goto err; + if (!exact) { + ret = DB_NOTFOUND; + goto err; + } + if ((ret = __bam_iitem(dbp, &t->bt_csp->page, + &t->bt_csp->indx, key, data, flags, 0)) == DB_NEEDSPLIT) { + if ((ret = __bam_stkrel(dbp)) != 0) + goto err; + goto split; + } + if ((ret = __bam_stkrel(dbp)) != 0) + goto err; + + if (flags != DB_CURRENT) { + /* Adjust the counts. */ + if ((ret = __bam_adjust(dbp, t, 1)) != 0) + goto err; + + switch (flags) { + case DB_AFTER: + /* Adjust the cursors. */ + __ram_ca(dbp, cp->recno, CA_IAFTER); + + /* Set this cursor to reference the new record. */ + cp->recno = copy.recno + 1; + break; + case DB_BEFORE: + /* Adjust the cursors. */ + __ram_ca(dbp, cp->recno, CA_IBEFORE); + + /* Set this cursor to reference the new record. */ + cp->recno = copy.recno; + break; + } + + } + + /* + * The cursor was reset, so the delete adjustment is no + * longer necessary. + */ + CD_CLR(dbp, cp); + +err: if (ret != 0) + *cp = copy; + + PUTHANDLE(dbp); + return (ret); +} + +/* + * __ram_ca -- + * Adjust cursors. + * + * PUBLIC: void __ram_ca __P((DB *, db_recno_t, ca_recno_arg)); + */ +void +__ram_ca(dbp, recno, op) + DB *dbp; + db_recno_t recno; + ca_recno_arg op; +{ + DBC *dbc; + RCURSOR *cp; + + /* + * Adjust the cursors. See the comment in __bam_ca_delete(). + */ + DB_THREAD_LOCK(dbp); + for (dbc = TAILQ_FIRST(&dbp->curs_queue); + dbc != NULL; dbc = TAILQ_NEXT(dbc, links)) { + cp = (RCURSOR *)dbc->internal; + switch (op) { + case CA_DELETE: + if (recno > cp->recno) + --cp->recno; + break; + case CA_IAFTER: + if (recno > cp->recno) + ++cp->recno; + break; + case CA_IBEFORE: + if (recno >= cp->recno) + ++cp->recno; + break; + } + } + DB_THREAD_UNLOCK(dbp); +} + +#ifdef DEBUG +/* + * __ram_cprint -- + * Display the current recno cursor list. + */ +int +__ram_cprint(dbp) + DB *dbp; +{ + DBC *dbc; + RCURSOR *cp; + + DB_THREAD_LOCK(dbp); + for (dbc = TAILQ_FIRST(&dbp->curs_queue); + dbc != NULL; dbc = TAILQ_NEXT(dbc, links)) { + cp = (RCURSOR *)dbc->internal; + fprintf(stderr, + "%#0x: recno: %lu\n", (u_int)cp, (u_long)cp->recno); + } + DB_THREAD_UNLOCK(dbp); + return (0); +} +#endif /* DEBUG */ + +/* + * __ram_getno -- + * Check the user's record number, and make sure we've seen it. + * + * PUBLIC: int __ram_getno __P((DB *, const DBT *, db_recno_t *, int)); + */ +int +__ram_getno(dbp, key, rep, can_create) + DB *dbp; + const DBT *key; + db_recno_t *rep; + int can_create; +{ + db_recno_t recno; + + /* Check the user's record number. */ + if ((recno = *(db_recno_t *)key->data) == 0) { + __db_err(dbp->dbenv, "illegal record number of 0"); + return (EINVAL); + } + if (rep != NULL) + *rep = recno; + + /* + * Btree can neither create records or read them in. Recno can + * do both, see if we can find the record. + */ + return (dbp->type == DB_RECNO ? + __ram_update(dbp, recno, can_create) : 0); +} + +/* + * __ram_snapshot -- + * Read in any remaining records from the backing input file. + * + * PUBLIC: int __ram_snapshot __P((DB *)); + */ +int +__ram_snapshot(dbp) + DB *dbp; +{ + return (__ram_update(dbp, DB_MAX_RECORDS, 0)); +} + +/* + * __ram_update -- + * Ensure the tree has records up to and including the specified one. + */ +static int +__ram_update(dbp, recno, can_create) + DB *dbp; + db_recno_t recno; + int can_create; +{ + BTREE *t; + RECNO *rp; + db_recno_t nrecs; + int ret; + + t = dbp->internal; + rp = t->bt_recno; + + /* + * If we can't create records and we've read the entire backing input + * file, we're done. + */ + if (!can_create && F_ISSET(rp, RECNO_EOF)) + return (0); + + /* + * If we haven't seen this record yet, try to get it from the original + * file. + */ + if ((ret = __bam_nrecs(dbp, &nrecs)) != 0) + return (ret); + if (!F_ISSET(rp, RECNO_EOF) && recno > nrecs) { + if ((ret = rp->re_irec(dbp, recno)) != 0) + return (ret); + if ((ret = __bam_nrecs(dbp, &nrecs)) != 0) + return (ret); + } + + /* + * If we can create records, create empty ones up to the requested + * record. + */ + if (!can_create || recno <= nrecs + 1) + return (0); + + t->bt_rdata.dlen = 0; + t->bt_rdata.doff = 0; + t->bt_rdata.flags = 0; + if (F_ISSET(dbp, DB_RE_FIXEDLEN)) { + if (t->bt_rdata.ulen < rp->re_len) { + t->bt_rdata.data = t->bt_rdata.data == NULL ? + (void *)malloc(rp->re_len) : + (void *)realloc(t->bt_rdata.data, rp->re_len); + if (t->bt_rdata.data == NULL) { + t->bt_rdata.ulen = 0; + return (ENOMEM); + } + t->bt_rdata.ulen = rp->re_len; + } + t->bt_rdata.size = rp->re_len; + memset(t->bt_rdata.data, rp->re_pad, rp->re_len); + } else + t->bt_rdata.size = 0; + + while (recno > ++nrecs) + if ((ret = __ram_add(dbp, + &nrecs, &t->bt_rdata, 0, BI_DELETED)) != 0) + return (ret); + return (0); +} + +/* + * __ram_source -- + * Load information about the backing file. + */ +static int +__ram_source(dbp, rp, fname) + DB *dbp; + RECNO *rp; + const char *fname; +{ + off_t size; + int oflags, ret; + + if ((ret = __db_appname(dbp->dbenv, + DB_APP_DATA, NULL, fname, NULL, &rp->re_source)) != 0) + return (ret); + + oflags = F_ISSET(dbp, DB_AM_RDONLY) ? DB_RDONLY : 0; + if ((ret = + __db_fdopen(rp->re_source, oflags, oflags, 0, &rp->re_fd)) != 0) { + __db_err(dbp->dbenv, "%s: %s", rp->re_source, strerror(ret)); + goto err; + } + + /* + * XXX + * 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, or 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 ((ret = + __db_stat(dbp->dbenv, rp->re_source, rp->re_fd, &size, NULL)) != 0) + goto err; + if (size == 0) { + F_SET(rp, RECNO_EOF); + return (0); + } + + if ((ret = __db_mmap(rp->re_fd, (size_t)size, 1, 1, &rp->re_smap)) != 0) + goto err; + rp->re_cmap = rp->re_smap; + rp->re_emap = (u_int8_t *)rp->re_smap + (rp->re_msize = size); + rp->re_irec = F_ISSET(dbp, DB_RE_FIXEDLEN) ? __ram_fmap : __ram_vmap; + return (0); + +err: FREES(rp->re_source) + return (ret); +} + +/* + * __ram_writeback -- + * Rewrite the backing file. + */ +static int +__ram_writeback(dbp) + DB *dbp; +{ + RECNO *rp; + DBT key, data; + db_recno_t keyno; + ssize_t nw; + int fd, ret, t_ret; + u_int8_t delim, *pad; + + rp = ((BTREE *)dbp->internal)->bt_recno; + + /* If the file wasn't modified, we're done. */ + if (!F_ISSET(rp, RECNO_MODIFIED)) + return (0); + + /* If there's no backing source file, we're done. */ + if (rp->re_source == NULL) { + F_CLR(rp, RECNO_MODIFIED); + return (0); + } + + /* + * Read any remaining records into the tree. + * + * XXX + * This is why we can't support transactions when applications specify + * backing (re_source) files. At this point we have to read in the + * rest of the records from the file so that we can write all of the + * records back out again, which could modify a page for which we'd + * have to log changes and which we don't have locked. This could be + * partially fixed by taking a snapshot of the entire file during the + * db_open(), or, since db_open() isn't transaction protected, as part + * of the first DB operation. But, if a checkpoint occurs then, the + * part of the log holding the copy of the file could be discarded, and + * that would make it impossible to recover in the face of disaster. + * This could all probably be fixed, but it would require transaction + * protecting the backing source file, i.e. mpool would have to know + * about it, and we don't want to go there. + */ + if ((ret = __ram_snapshot(dbp)) != 0 && ret != DB_NOTFOUND) + return (ret); + + /* + * !!! + * Close any underlying mmap region. This is required for Windows NT + * (4.0, Service Pack 2) -- if the file is still mapped, the following + * open will fail. + */ + if (rp->re_smap != NULL) { + (void)__db_munmap(rp->re_smap, rp->re_msize); + rp->re_smap = NULL; + } + + /* Get rid of any backing file descriptor, just on GP's. */ + if (rp->re_fd != -1) { + (void)__db_close(rp->re_fd); + rp->re_fd = -1; + } + + /* Open the file, truncating it. */ + if ((ret = __db_fdopen(rp->re_source, + DB_SEQUENTIAL | DB_TRUNCATE, + DB_SEQUENTIAL | DB_TRUNCATE, 0, &fd)) != 0) { + __db_err(dbp->dbenv, "%s: %s", rp->re_source, strerror(ret)); + return (ret); + } + + /* + * We step through the records, writing each one out. Use the record + * number and the dbp->get() function, instead of a cursor, so we find + * and write out "deleted" or non-existent records. + */ + memset(&key, 0, sizeof(key)); + memset(&data, 0, sizeof(data)); + key.size = sizeof(db_recno_t); + key.data = &keyno; + + /* + * We'll need the delimiter if we're doing variable-length records, + * and the pad character if we're doing fixed-length records. + */ + delim = rp->re_delim; + if (F_ISSET(dbp, DB_RE_FIXEDLEN)) { + if ((pad = malloc(rp->re_len)) == NULL) { + ret = ENOMEM; + goto err; + } + memset(pad, rp->re_pad, rp->re_len); + } else + pad = NULL; /* XXX: Shut the compiler up. */ + for (keyno = 1;; ++keyno) { + switch (ret = dbp->get(dbp, NULL, &key, &data, 0)) { + case 0: + if ((ret = + __db_write(fd, data.data, data.size, &nw)) != 0) + goto err; + if (nw != (ssize_t)data.size) { + ret = EIO; + goto err; + } + break; + case DB_KEYEMPTY: + if (F_ISSET(dbp, DB_RE_FIXEDLEN)) { + if ((ret = + __db_write(fd, pad, rp->re_len, &nw)) != 0) + goto err; + if (nw != (ssize_t) rp->re_len) { + ret = EIO; + goto err; + } + } + break; + case DB_NOTFOUND: + ret = 0; + goto done; + } + if (!F_ISSET(dbp, DB_RE_FIXEDLEN)) { + if ((ret = __db_write(fd, &delim, 1, &nw)) != 0) + goto err; + if (nw != 1) { + ret = EIO; + goto err; + } + } + } + +err: +done: /* Close the file descriptor. */ + if ((t_ret = __db_close(fd)) != 0 || ret == 0) + ret = t_ret; + + if (ret == 0) + F_CLR(rp, RECNO_MODIFIED); + return (ret); +} + +/* + * __ram_fmap -- + * Get fixed length records from a file. + */ +static int +__ram_fmap(dbp, top) + DB *dbp; + db_recno_t top; +{ + BTREE *t; + DBT data; + RECNO *rp; + db_recno_t recno; + u_int32_t len; + u_int8_t *sp, *ep, *p; + int ret; + + if ((ret = __bam_nrecs(dbp, &recno)) != 0) + return (ret); + + t = dbp->internal; + rp = t->bt_recno; + if (t->bt_rdata.ulen < rp->re_len) { + t->bt_rdata.data = t->bt_rdata.data == NULL ? + (void *)malloc(rp->re_len) : + (void *)realloc(t->bt_rdata.data, rp->re_len); + if (t->bt_rdata.data == NULL) { + t->bt_rdata.ulen = 0; + return (ENOMEM); + } + t->bt_rdata.ulen = rp->re_len; + } + + memset(&data, 0, sizeof(data)); + data.data = t->bt_rdata.data; + data.size = rp->re_len; + + sp = (u_int8_t *)rp->re_cmap; + ep = (u_int8_t *)rp->re_emap; + while (recno <= top) { + if (sp >= ep) { + F_SET(rp, RECNO_EOF); + return (DB_NOTFOUND); + } + len = rp->re_len; + for (p = t->bt_rdata.data; + sp < ep && len > 0; *p++ = *sp++, --len); + + /* + * Another process may have read some portion of the input + * file already, in which case we just want to discard the + * new record. + * + * XXX + * We should just do a seek, since the records are fixed + * length. + */ + if (rp->re_last >= recno) { + if (len != 0) + memset(p, rp->re_pad, len); + + ++recno; + if ((ret = __ram_add(dbp, &recno, &data, 0, 0)) != 0) + return (ret); + } + ++rp->re_last; + } + rp->re_cmap = sp; + return (0); +} + +/* + * __ram_vmap -- + * Get variable length records from a file. + */ +static int +__ram_vmap(dbp, top) + DB *dbp; + db_recno_t top; +{ + BTREE *t; + DBT data; + RECNO *rp; + db_recno_t recno; + u_int8_t *sp, *ep; + int delim, ret; + + t = dbp->internal; + rp = t->bt_recno; + + if ((ret = __bam_nrecs(dbp, &recno)) != 0) + return (ret); + + memset(&data, 0, sizeof(data)); + + delim = rp->re_delim; + + sp = (u_int8_t *)rp->re_cmap; + ep = (u_int8_t *)rp->re_emap; + while (recno <= top) { + if (sp >= ep) { + F_SET(rp, RECNO_EOF); + return (DB_NOTFOUND); + } + for (data.data = sp; sp < ep && *sp != delim; ++sp); + + /* + * Another process may have read some portion of the input + * file already, in which case we just want to discard the + * new record. + */ + if (rp->re_last >= recno) { + data.size = sp - (u_int8_t *)data.data; + ++recno; + if ((ret = __ram_add(dbp, &recno, &data, 0, 0)) != 0) + return (ret); + } + ++rp->re_last; + ++sp; + } + rp->re_cmap = sp; + return (0); +} + +/* + * __ram_add -- + * Add records into the tree. + */ +static int +__ram_add(dbp, recnop, data, flags, bi_flags) + DB *dbp; + db_recno_t *recnop; + DBT *data; + int flags, bi_flags; +{ + BTREE *t; + PAGE *h; + db_indx_t indx; + int exact, ret, stack; + + t = dbp->internal; + +retry: /* Find the slot for insertion. */ + if ((ret = __bam_rsearch(dbp, recnop, + S_INSERT | (LF_ISSET(DB_APPEND) ? S_APPEND : 0), 1, &exact)) != 0) + return (ret); + h = t->bt_csp->page; + indx = t->bt_csp->indx; + stack = 1; + + /* + * The recno access method doesn't currently support duplicates, so + * if an identical key is already in the tree we're either overwriting + * it or an error is returned. + */ + if (exact && LF_ISSET(DB_NOOVERWRITE)) { + ret = DB_KEYEXIST; + goto err; + } + + /* + * Select the arguments for __bam_iitem() and do the insert. If the + * key is an exact match, or we're replacing the data item with a + * new data item. If the key isn't an exact match, we're inserting + * a new key/data pair, before the search location. + */ + if ((ret = __bam_iitem(dbp, &h, &indx, NULL, + data, exact ? DB_CURRENT : DB_BEFORE, bi_flags)) == DB_NEEDSPLIT) { + (void)__bam_stkrel(dbp); + stack = 0; + if ((ret = __bam_split(dbp, recnop)) != 0) + goto err; + goto retry; + } + + if (!exact && ret == 0) + __bam_adjust(dbp, t, 1); + +err: if (stack) + __bam_stkrel(dbp); + return (ret); +} |