]> git.ozlabs.org Git - ccan/blobdiff - junkcode/rusty@rustcorp.com.au-ntdb/ntdb.c
ccan/ntdb: demote to junkcode.
[ccan] / junkcode / rusty@rustcorp.com.au-ntdb / ntdb.c
diff --git a/junkcode/rusty@rustcorp.com.au-ntdb/ntdb.c b/junkcode/rusty@rustcorp.com.au-ntdb/ntdb.c
new file mode 100644 (file)
index 0000000..51fbbca
--- /dev/null
@@ -0,0 +1,601 @@
+ /*
+   Trivial Database 2: fetch, store and misc routines.
+   Copyright (C) Rusty Russell 2010
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+#include "private.h"
+#ifndef HAVE_LIBREPLACE
+#include <stdarg.h>
+#endif
+
+static enum NTDB_ERROR update_rec_hdr(struct ntdb_context *ntdb,
+                                    ntdb_off_t off,
+                                    ntdb_len_t keylen,
+                                    ntdb_len_t datalen,
+                                    struct ntdb_used_record *rec)
+{
+       uint64_t dataroom = rec_data_length(rec) + rec_extra_padding(rec);
+       enum NTDB_ERROR ecode;
+
+       ecode = set_header(ntdb, rec, NTDB_USED_MAGIC, keylen, datalen,
+                          keylen + dataroom);
+       if (ecode == NTDB_SUCCESS) {
+               ecode = ntdb_write_convert(ntdb, off, rec, sizeof(*rec));
+       }
+       return ecode;
+}
+
+static enum NTDB_ERROR replace_data(struct ntdb_context *ntdb,
+                                  struct hash_info *h,
+                                  NTDB_DATA key, NTDB_DATA dbuf,
+                                  ntdb_off_t old_off, ntdb_len_t old_room,
+                                  bool growing)
+{
+       ntdb_off_t new_off;
+       enum NTDB_ERROR ecode;
+
+       /* Allocate a new record. */
+       new_off = alloc(ntdb, key.dsize, dbuf.dsize, NTDB_USED_MAGIC, growing);
+       if (NTDB_OFF_IS_ERR(new_off)) {
+               return NTDB_OFF_TO_ERR(new_off);
+       }
+
+       /* We didn't like the existing one: remove it. */
+       if (old_off) {
+               ntdb->stats.frees++;
+               ecode = add_free_record(ntdb, old_off,
+                                       sizeof(struct ntdb_used_record)
+                                       + key.dsize + old_room,
+                                       NTDB_LOCK_WAIT, true);
+               if (ecode == NTDB_SUCCESS)
+                       ecode = replace_in_hash(ntdb, h, new_off);
+       } else {
+               ecode = add_to_hash(ntdb, h, new_off);
+       }
+       if (ecode != NTDB_SUCCESS) {
+               return ecode;
+       }
+
+       new_off += sizeof(struct ntdb_used_record);
+       ecode = ntdb->io->twrite(ntdb, new_off, key.dptr, key.dsize);
+       if (ecode != NTDB_SUCCESS) {
+               return ecode;
+       }
+
+       new_off += key.dsize;
+       ecode = ntdb->io->twrite(ntdb, new_off, dbuf.dptr, dbuf.dsize);
+       if (ecode != NTDB_SUCCESS) {
+               return ecode;
+       }
+
+       if (ntdb->flags & NTDB_SEQNUM)
+               ntdb_inc_seqnum(ntdb);
+
+       return NTDB_SUCCESS;
+}
+
+static enum NTDB_ERROR update_data(struct ntdb_context *ntdb,
+                                 ntdb_off_t off,
+                                 NTDB_DATA dbuf,
+                                 ntdb_len_t extra)
+{
+       enum NTDB_ERROR ecode;
+
+       ecode = ntdb->io->twrite(ntdb, off, dbuf.dptr, dbuf.dsize);
+       if (ecode == NTDB_SUCCESS && extra) {
+               /* Put a zero in; future versions may append other data. */
+               ecode = ntdb->io->twrite(ntdb, off + dbuf.dsize, "", 1);
+       }
+       if (ntdb->flags & NTDB_SEQNUM)
+               ntdb_inc_seqnum(ntdb);
+
+       return ecode;
+}
+
+_PUBLIC_ enum NTDB_ERROR ntdb_store(struct ntdb_context *ntdb,
+                        NTDB_DATA key, NTDB_DATA dbuf, int flag)
+{
+       struct hash_info h;
+       ntdb_off_t off;
+       ntdb_len_t old_room = 0;
+       struct ntdb_used_record rec;
+       enum NTDB_ERROR ecode;
+
+       off = find_and_lock(ntdb, key, F_WRLCK, &h, &rec, NULL);
+       if (NTDB_OFF_IS_ERR(off)) {
+               return NTDB_OFF_TO_ERR(off);
+       }
+
+       /* Now we have lock on this hash bucket. */
+       if (flag == NTDB_INSERT) {
+               if (off) {
+                       ecode = NTDB_ERR_EXISTS;
+                       goto out;
+               }
+       } else {
+               if (off) {
+                       old_room = rec_data_length(&rec)
+                               + rec_extra_padding(&rec);
+                       if (old_room >= dbuf.dsize) {
+                               /* Can modify in-place.  Easy! */
+                               ecode = update_rec_hdr(ntdb, off,
+                                                      key.dsize, dbuf.dsize,
+                                                      &rec);
+                               if (ecode != NTDB_SUCCESS) {
+                                       goto out;
+                               }
+                               ecode = update_data(ntdb,
+                                                   off + sizeof(rec)
+                                                   + key.dsize, dbuf,
+                                                   old_room - dbuf.dsize);
+                               if (ecode != NTDB_SUCCESS) {
+                                       goto out;
+                               }
+                               ntdb_unlock_hash(ntdb, h.h, F_WRLCK);
+                               return NTDB_SUCCESS;
+                       }
+               } else {
+                       if (flag == NTDB_MODIFY) {
+                               /* if the record doesn't exist and we
+                                  are in NTDB_MODIFY mode then we should fail
+                                  the store */
+                               ecode = NTDB_ERR_NOEXIST;
+                               goto out;
+                       }
+               }
+       }
+
+       /* If we didn't use the old record, this implies we're growing. */
+       ecode = replace_data(ntdb, &h, key, dbuf, off, old_room, off);
+out:
+       ntdb_unlock_hash(ntdb, h.h, F_WRLCK);
+       return ecode;
+}
+
+_PUBLIC_ enum NTDB_ERROR ntdb_append(struct ntdb_context *ntdb,
+                         NTDB_DATA key, NTDB_DATA dbuf)
+{
+       struct hash_info h;
+       ntdb_off_t off;
+       struct ntdb_used_record rec;
+       ntdb_len_t old_room = 0, old_dlen;
+       unsigned char *newdata;
+       NTDB_DATA new_dbuf;
+       enum NTDB_ERROR ecode;
+
+       off = find_and_lock(ntdb, key, F_WRLCK, &h, &rec, NULL);
+       if (NTDB_OFF_IS_ERR(off)) {
+               return NTDB_OFF_TO_ERR(off);
+       }
+
+       if (off) {
+               old_dlen = rec_data_length(&rec);
+               old_room = old_dlen + rec_extra_padding(&rec);
+
+               /* Fast path: can append in place. */
+               if (rec_extra_padding(&rec) >= dbuf.dsize) {
+                       ecode = update_rec_hdr(ntdb, off, key.dsize,
+                                              old_dlen + dbuf.dsize, &rec);
+                       if (ecode != NTDB_SUCCESS) {
+                               goto out;
+                       }
+
+                       off += sizeof(rec) + key.dsize + old_dlen;
+                       ecode = update_data(ntdb, off, dbuf,
+                                           rec_extra_padding(&rec));
+                       goto out;
+               }
+
+               /* Slow path. */
+               newdata = ntdb->alloc_fn(ntdb, key.dsize + old_dlen + dbuf.dsize,
+                                    ntdb->alloc_data);
+               if (!newdata) {
+                       ecode = ntdb_logerr(ntdb, NTDB_ERR_OOM, NTDB_LOG_ERROR,
+                                          "ntdb_append:"
+                                          " failed to allocate %zu bytes",
+                                          (size_t)(key.dsize + old_dlen
+                                                   + dbuf.dsize));
+                       goto out;
+               }
+               ecode = ntdb->io->tread(ntdb, off + sizeof(rec) + key.dsize,
+                                      newdata, old_dlen);
+               if (ecode != NTDB_SUCCESS) {
+                       goto out_free_newdata;
+               }
+               memcpy(newdata + old_dlen, dbuf.dptr, dbuf.dsize);
+               new_dbuf.dptr = newdata;
+               new_dbuf.dsize = old_dlen + dbuf.dsize;
+       } else {
+               newdata = NULL;
+               new_dbuf = dbuf;
+       }
+
+       /* If they're using ntdb_append(), it implies they're growing record. */
+       ecode = replace_data(ntdb, &h, key, new_dbuf, off, old_room, true);
+
+out_free_newdata:
+       ntdb->free_fn(newdata, ntdb->alloc_data);
+out:
+       ntdb_unlock_hash(ntdb, h.h, F_WRLCK);
+       return ecode;
+}
+
+_PUBLIC_ enum NTDB_ERROR ntdb_fetch(struct ntdb_context *ntdb, NTDB_DATA key,
+                                   NTDB_DATA *data)
+{
+       ntdb_off_t off;
+       struct ntdb_used_record rec;
+       struct hash_info h;
+       enum NTDB_ERROR ecode;
+       const char *keyp;
+
+       off = find_and_lock(ntdb, key, F_RDLCK, &h, &rec, &keyp);
+       if (NTDB_OFF_IS_ERR(off)) {
+               return NTDB_OFF_TO_ERR(off);
+       }
+
+       if (!off) {
+               ecode = NTDB_ERR_NOEXIST;
+       } else {
+               data->dsize = rec_data_length(&rec);
+               data->dptr = ntdb->alloc_fn(ntdb, data->dsize, ntdb->alloc_data);
+               if (unlikely(!data->dptr)) {
+                       ecode = NTDB_ERR_OOM;
+               } else {
+                       memcpy(data->dptr, keyp + key.dsize, data->dsize);
+                       ecode = NTDB_SUCCESS;
+               }
+               ntdb_access_release(ntdb, keyp);
+       }
+
+       ntdb_unlock_hash(ntdb, h.h, F_RDLCK);
+       return ecode;
+}
+
+_PUBLIC_ bool ntdb_exists(struct ntdb_context *ntdb, NTDB_DATA key)
+{
+       ntdb_off_t off;
+       struct ntdb_used_record rec;
+       struct hash_info h;
+
+       off = find_and_lock(ntdb, key, F_RDLCK, &h, &rec, NULL);
+       if (NTDB_OFF_IS_ERR(off)) {
+               return false;
+       }
+       ntdb_unlock_hash(ntdb, h.h, F_RDLCK);
+
+       return off ? true : false;
+}
+
+_PUBLIC_ enum NTDB_ERROR ntdb_delete(struct ntdb_context *ntdb, NTDB_DATA key)
+{
+       ntdb_off_t off;
+       struct ntdb_used_record rec;
+       struct hash_info h;
+       enum NTDB_ERROR ecode;
+
+       off = find_and_lock(ntdb, key, F_WRLCK, &h, &rec, NULL);
+       if (NTDB_OFF_IS_ERR(off)) {
+               return NTDB_OFF_TO_ERR(off);
+       }
+
+       if (!off) {
+               ecode = NTDB_ERR_NOEXIST;
+               goto unlock;
+       }
+
+       ecode = delete_from_hash(ntdb, &h);
+       if (ecode != NTDB_SUCCESS) {
+               goto unlock;
+       }
+
+       /* Free the deleted entry. */
+       ntdb->stats.frees++;
+       ecode = add_free_record(ntdb, off,
+                               sizeof(struct ntdb_used_record)
+                               + rec_key_length(&rec)
+                               + rec_data_length(&rec)
+                               + rec_extra_padding(&rec),
+                               NTDB_LOCK_WAIT, true);
+
+       if (ntdb->flags & NTDB_SEQNUM)
+               ntdb_inc_seqnum(ntdb);
+
+unlock:
+       ntdb_unlock_hash(ntdb, h.h, F_WRLCK);
+       return ecode;
+}
+
+_PUBLIC_ unsigned int ntdb_get_flags(struct ntdb_context *ntdb)
+{
+       return ntdb->flags;
+}
+
+static bool inside_transaction(const struct ntdb_context *ntdb)
+{
+       return ntdb->transaction != NULL;
+}
+
+static bool readonly_changable(struct ntdb_context *ntdb, const char *caller)
+{
+       if (inside_transaction(ntdb)) {
+               ntdb_logerr(ntdb, NTDB_ERR_EINVAL, NTDB_LOG_USE_ERROR,
+                           "%s: can't change"
+                           " NTDB_RDONLY inside transaction",
+                           caller);
+               return false;
+       }
+       return true;
+}
+
+_PUBLIC_ void ntdb_add_flag(struct ntdb_context *ntdb, unsigned flag)
+{
+       if (ntdb->flags & NTDB_INTERNAL) {
+               ntdb_logerr(ntdb, NTDB_ERR_EINVAL, NTDB_LOG_USE_ERROR,
+                           "ntdb_add_flag: internal db");
+               return;
+       }
+       switch (flag) {
+       case NTDB_NOLOCK:
+               ntdb->flags |= NTDB_NOLOCK;
+               break;
+       case NTDB_NOMMAP:
+               if (ntdb->file->direct_count) {
+                       ntdb_logerr(ntdb, NTDB_ERR_EINVAL, NTDB_LOG_USE_ERROR,
+                                   "ntdb_add_flag: Can't get NTDB_NOMMAP from"
+                                   " ntdb_parse_record!");
+                       return;
+               }
+               ntdb->flags |= NTDB_NOMMAP;
+#ifndef HAVE_INCOHERENT_MMAP
+               ntdb_munmap(ntdb);
+#endif
+               break;
+       case NTDB_NOSYNC:
+               ntdb->flags |= NTDB_NOSYNC;
+               break;
+       case NTDB_SEQNUM:
+               ntdb->flags |= NTDB_SEQNUM;
+               break;
+       case NTDB_ALLOW_NESTING:
+               ntdb->flags |= NTDB_ALLOW_NESTING;
+               break;
+       case NTDB_RDONLY:
+               if (readonly_changable(ntdb, "ntdb_add_flag"))
+                       ntdb->flags |= NTDB_RDONLY;
+               break;
+       default:
+               ntdb_logerr(ntdb, NTDB_ERR_EINVAL, NTDB_LOG_USE_ERROR,
+                           "ntdb_add_flag: Unknown flag %u", flag);
+       }
+}
+
+_PUBLIC_ void ntdb_remove_flag(struct ntdb_context *ntdb, unsigned flag)
+{
+       if (ntdb->flags & NTDB_INTERNAL) {
+               ntdb_logerr(ntdb, NTDB_ERR_EINVAL, NTDB_LOG_USE_ERROR,
+                           "ntdb_remove_flag: internal db");
+               return;
+       }
+       switch (flag) {
+       case NTDB_NOLOCK:
+               ntdb->flags &= ~NTDB_NOLOCK;
+               break;
+       case NTDB_NOMMAP:
+               ntdb->flags &= ~NTDB_NOMMAP;
+#ifndef HAVE_INCOHERENT_MMAP
+               /* If mmap incoherent, we were mmaping anyway. */
+               ntdb_mmap(ntdb);
+#endif
+               break;
+       case NTDB_NOSYNC:
+               ntdb->flags &= ~NTDB_NOSYNC;
+               break;
+       case NTDB_SEQNUM:
+               ntdb->flags &= ~NTDB_SEQNUM;
+               break;
+       case NTDB_ALLOW_NESTING:
+               ntdb->flags &= ~NTDB_ALLOW_NESTING;
+               break;
+       case NTDB_RDONLY:
+               if ((ntdb->open_flags & O_ACCMODE) == O_RDONLY) {
+                       ntdb_logerr(ntdb, NTDB_ERR_EINVAL, NTDB_LOG_USE_ERROR,
+                                   "ntdb_remove_flag: can't"
+                                   " remove NTDB_RDONLY on ntdb"
+                                   " opened with O_RDONLY");
+                       break;
+               }
+               if (readonly_changable(ntdb, "ntdb_remove_flag"))
+                       ntdb->flags &= ~NTDB_RDONLY;
+               break;
+       default:
+               ntdb_logerr(ntdb, NTDB_ERR_EINVAL, NTDB_LOG_USE_ERROR,
+                           "ntdb_remove_flag: Unknown flag %u",
+                           flag);
+       }
+}
+
+_PUBLIC_ const char *ntdb_errorstr(enum NTDB_ERROR ecode)
+{
+       /* Gcc warns if you miss a case in the switch, so use that. */
+       switch (NTDB_ERR_TO_OFF(ecode)) {
+       case NTDB_ERR_TO_OFF(NTDB_SUCCESS): return "Success";
+       case NTDB_ERR_TO_OFF(NTDB_ERR_CORRUPT): return "Corrupt database";
+       case NTDB_ERR_TO_OFF(NTDB_ERR_IO): return "IO Error";
+       case NTDB_ERR_TO_OFF(NTDB_ERR_LOCK): return "Locking error";
+       case NTDB_ERR_TO_OFF(NTDB_ERR_OOM): return "Out of memory";
+       case NTDB_ERR_TO_OFF(NTDB_ERR_EXISTS): return "Record exists";
+       case NTDB_ERR_TO_OFF(NTDB_ERR_EINVAL): return "Invalid parameter";
+       case NTDB_ERR_TO_OFF(NTDB_ERR_NOEXIST): return "Record does not exist";
+       case NTDB_ERR_TO_OFF(NTDB_ERR_RDONLY): return "write not permitted";
+       }
+       return "Invalid error code";
+}
+
+enum NTDB_ERROR COLD ntdb_logerr(struct ntdb_context *ntdb,
+                              enum NTDB_ERROR ecode,
+                              enum ntdb_log_level level,
+                              const char *fmt, ...)
+{
+       char *message;
+       va_list ap;
+       size_t len;
+       /* ntdb_open paths care about errno, so save it. */
+       int saved_errno = errno;
+
+       if (!ntdb->log_fn)
+               return ecode;
+
+       va_start(ap, fmt);
+       len = vsnprintf(NULL, 0, fmt, ap);
+       va_end(ap);
+
+       message = ntdb->alloc_fn(ntdb, len + 1, ntdb->alloc_data);
+       if (!message) {
+               ntdb->log_fn(ntdb, NTDB_LOG_ERROR, NTDB_ERR_OOM,
+                           "out of memory formatting message:", ntdb->log_data);
+               ntdb->log_fn(ntdb, level, ecode, fmt, ntdb->log_data);
+       } else {
+               va_start(ap, fmt);
+               vsnprintf(message, len+1, fmt, ap);
+               va_end(ap);
+               ntdb->log_fn(ntdb, level, ecode, message, ntdb->log_data);
+               ntdb->free_fn(message, ntdb->alloc_data);
+       }
+       errno = saved_errno;
+       return ecode;
+}
+
+_PUBLIC_ enum NTDB_ERROR ntdb_parse_record_(struct ntdb_context *ntdb,
+                                NTDB_DATA key,
+                                enum NTDB_ERROR (*parse)(NTDB_DATA k,
+                                                        NTDB_DATA d,
+                                                        void *data),
+                                void *data)
+{
+       ntdb_off_t off;
+       struct ntdb_used_record rec;
+       struct hash_info h;
+       enum NTDB_ERROR ecode;
+       const char *keyp;
+
+       off = find_and_lock(ntdb, key, F_RDLCK, &h, &rec, &keyp);
+       if (NTDB_OFF_IS_ERR(off)) {
+               return NTDB_OFF_TO_ERR(off);
+       }
+
+       if (!off) {
+               ecode = NTDB_ERR_NOEXIST;
+       } else {
+               unsigned int old_flags;
+               NTDB_DATA d = ntdb_mkdata(keyp + key.dsize,
+                                         rec_data_length(&rec));
+
+               /*
+                * Make sure they don't try to write db, since they
+                * have read lock!  They can if they've done
+                * ntdb_lockall(): if it was ntdb_lockall_read, that'll
+                * stop them doing a write operation anyway.
+                */
+               old_flags = ntdb->flags;
+               if (!ntdb->file->allrecord_lock.count &&
+                   !(ntdb->flags & NTDB_NOLOCK)) {
+                       ntdb->flags |= NTDB_RDONLY;
+               }
+               ecode = parse(key, d, data);
+               ntdb->flags = old_flags;
+               ntdb_access_release(ntdb, keyp);
+       }
+
+       ntdb_unlock_hash(ntdb, h.h, F_RDLCK);
+       return ecode;
+}
+
+_PUBLIC_ const char *ntdb_name(const struct ntdb_context *ntdb)
+{
+       return ntdb->name;
+}
+
+_PUBLIC_ int64_t ntdb_get_seqnum(struct ntdb_context *ntdb)
+{
+       return ntdb_read_off(ntdb, offsetof(struct ntdb_header, seqnum));
+}
+
+
+_PUBLIC_ int ntdb_fd(const struct ntdb_context *ntdb)
+{
+       return ntdb->file->fd;
+}
+
+struct traverse_state {
+       enum NTDB_ERROR error;
+       struct ntdb_context *dest_db;
+};
+
+/*
+  traverse function for repacking
+ */
+static int repack_traverse(struct ntdb_context *ntdb, NTDB_DATA key, NTDB_DATA data,
+                          struct traverse_state *state)
+{
+       state->error = ntdb_store(state->dest_db, key, data, NTDB_INSERT);
+       if (state->error != NTDB_SUCCESS) {
+               return -1;
+       }
+       return 0;
+}
+
+_PUBLIC_ enum NTDB_ERROR ntdb_repack(struct ntdb_context *ntdb)
+{
+       struct ntdb_context *tmp_db;
+       struct traverse_state state;
+
+       state.error = ntdb_transaction_start(ntdb);
+       if (state.error != NTDB_SUCCESS) {
+               return state.error;
+       }
+
+       tmp_db = ntdb_open("tmpdb", NTDB_INTERNAL, O_RDWR|O_CREAT, 0, NULL);
+       if (tmp_db == NULL) {
+               state.error = ntdb_logerr(ntdb, NTDB_ERR_OOM, NTDB_LOG_ERROR,
+                                        __location__
+                                        " Failed to create tmp_db");
+               ntdb_transaction_cancel(ntdb);
+               return state.error;
+       }
+
+       state.dest_db = tmp_db;
+       if (ntdb_traverse(ntdb, repack_traverse, &state) < 0) {
+               goto fail;
+       }
+
+       state.error = ntdb_wipe_all(ntdb);
+       if (state.error != NTDB_SUCCESS) {
+               goto fail;
+       }
+
+       state.dest_db = ntdb;
+       if (ntdb_traverse(tmp_db, repack_traverse, &state) < 0) {
+               goto fail;
+       }
+
+       ntdb_close(tmp_db);
+       return ntdb_transaction_commit(ntdb);
+
+fail:
+       ntdb_transaction_cancel(ntdb);
+       ntdb_close(tmp_db);
+       return state.error;
+}