tdb2: remove looping for read on normal files.

[ccan] / ccan / tdb2 / tdb.c

diff --git a/ccan/tdb2/tdb.c b/ccan/tdb2/tdb.c
index a4dbc53d6f237050fc8e9ae5310138a3e8e87913..e3b579d0f259ad94498fe740f84bef7dc52d9d2b 100644 (file)
--- a/ccan/tdb2/tdb.c
+++ b/ccan/tdb2/tdb.c
@@ -22,6 +22,24 @@ static bool tdb_already_open(dev_t device, ino_t ino)
        return false;
 }
 
+static bool read_all(int fd, void *buf, size_t len)
+{
+       while (len) {
+               ssize_t ret;
+               ret = read(fd, buf, len);
+               if (ret < 0)
+                       return false;
+               if (ret == 0) {
+                       /* ETOOSHORT? */
+                       errno = EWOULDBLOCK;
+                       return false;
+               }
+               buf = (char *)buf + ret;
+               len -= ret;
+       }
+       return true;
+}
+
 static uint64_t random_number(struct tdb_context *tdb)
 {
        int fd;
@@ -30,7 +48,7 @@ static uint64_t random_number(struct tdb_context *tdb)
 
        fd = open("/dev/urandom", O_RDONLY);
        if (fd >= 0) {
-               if (tdb_read_all(fd, &ret, sizeof(ret))) {
+               if (read_all(fd, &ret, sizeof(ret))) {
                        tdb_logerr(tdb, TDB_SUCCESS, TDB_DEBUG_TRACE,
                                 "tdb_open: random from /dev/urandom");
                        close(fd);
@@ -72,7 +90,7 @@ static uint64_t random_number(struct tdb_context *tdb)
 
 struct new_database {
        struct tdb_header hdr;
-       struct tdb_freelist flist;
+       struct tdb_freetable ftable;
 };
 
 /* initialise a new database */
@@ -101,11 +119,11 @@ static int tdb_new_database(struct tdb_context *tdb,
        memset(newdb.hdr.hashtable, 0, sizeof(newdb.hdr.hashtable));
 
        /* Free is empty. */
-       newdb.hdr.free_list = offsetof(struct new_database, flist);
-       memset(&newdb.flist, 0, sizeof(newdb.flist));
-       set_used_header(NULL, &newdb.flist.hdr, 0,
-                       sizeof(newdb.flist) - sizeof(newdb.flist.hdr),
-                       sizeof(newdb.flist) - sizeof(newdb.flist.hdr), 1);
+       newdb.hdr.free_table = offsetof(struct new_database, ftable);
+       memset(&newdb.ftable, 0, sizeof(newdb.ftable));
+       set_header(NULL, &newdb.ftable.hdr, TDB_FTABLE_MAGIC, 0,
+                  sizeof(newdb.ftable) - sizeof(newdb.ftable.hdr),
+                  sizeof(newdb.ftable) - sizeof(newdb.ftable.hdr), 0);
 
        /* Magic food */
        memset(newdb.hdr.magic_food, 0, sizeof(newdb.hdr.magic_food));
@@ -153,6 +171,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
        int saved_errno = 0;
        uint64_t hash_test;
        unsigned v;
+       ssize_t rlen;
        struct tdb_header hdr;
        struct tdb_attribute_seed *seed = NULL;
 
@@ -172,6 +191,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
        tdb->logfn = NULL;
        tdb->transaction = NULL;
        tdb->stats = NULL;
+       tdb->access = NULL;
        tdb_hash_init(tdb);
        tdb_io_init(tdb);
        tdb_lock_init(tdb);
@@ -228,7 +248,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
                }
                tdb_convert(tdb, &hdr.hash_seed, sizeof(hdr.hash_seed));
                tdb->hash_seed = hdr.hash_seed;
-               tdb_flist_init(tdb);
+               tdb_ftable_init(tdb);
                return tdb;
        }
 
@@ -252,17 +272,25 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
                goto fail;
        }
 
-       if (!tdb_pread_all(tdb->fd, &hdr, sizeof(hdr), 0)
-           || strcmp(hdr.magic_food, TDB_MAGIC_FOOD) != 0) {
-               if (!(open_flags & O_CREAT)) {
-                       tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_ERROR,
-                                  "tdb_open: %s is not a tdb file", name);
-                       goto fail;
-               }
+       /* If they used O_TRUNC, read will return 0. */
+       rlen = read(tdb->fd, &hdr, sizeof(hdr));
+       if (rlen == 0 && (open_flags & O_CREAT)) {
                if (tdb_new_database(tdb, seed, &hdr) == -1) {
                        goto fail;
                }
-       } else if (hdr.version != TDB_VERSION) {
+       } else if (rlen < 0) {
+               tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_ERROR,
+                          "tdb_open: error %s reading %s",
+                          strerror(errno), name);
+               goto fail;
+       } else if (rlen < sizeof(hdr)
+                  || strcmp(hdr.magic_food, TDB_MAGIC_FOOD) != 0) {
+               tdb_logerr(tdb, TDB_ERR_IO, TDB_DEBUG_ERROR,
+                          "tdb_open: %s is not a tdb file", name);
+               goto fail;
+       }
+
+       if (hdr.version != TDB_VERSION) {
                if (hdr.version == bswap_64(TDB_VERSION))
                        tdb->flags |= TDB_CONVERT;
                else {
@@ -323,7 +351,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
                goto fail;
        }
 
-       if (tdb_flist_init(tdb) == -1)
+       if (tdb_ftable_init(tdb) == -1)
                goto fail;
 
        tdb->next = tdbs;
@@ -376,7 +404,6 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
        return NULL;
 }
 
-/* FIXME: modify, don't rewrite! */
 static int update_rec_hdr(struct tdb_context *tdb,
                          tdb_off_t off,
                          tdb_len_t keylen,
@@ -386,7 +413,8 @@ static int update_rec_hdr(struct tdb_context *tdb,
 {
        uint64_t dataroom = rec_data_length(rec) + rec_extra_padding(rec);
 
-       if (set_used_header(tdb, rec, keylen, datalen, keylen + dataroom, h))
+       if (set_header(tdb, rec, TDB_USED_MAGIC, keylen, datalen,
+                      keylen + dataroom, h))
                return -1;
 
        return tdb_write_convert(tdb, off, rec, sizeof(*rec));
@@ -402,7 +430,8 @@ static int replace_data(struct tdb_context *tdb,
        tdb_off_t new_off;
 
        /* Allocate a new record. */
-       new_off = alloc(tdb, key.dsize, dbuf.dsize, h->h, growing);
+       new_off = alloc(tdb, key.dsize, dbuf.dsize, h->h, TDB_USED_MAGIC,
+                       growing);
        if (unlikely(new_off == TDB_OFF_ERR))
                return -1;
 
@@ -468,7 +497,6 @@ int tdb_store(struct tdb_context *tdb,
                                                  h.hlock_range, F_WRLCK);
                                return 0;
                        }
-                       /* FIXME: See if right record is free? */
                } else {
                        if (flag == TDB_MODIFY) {
                                /* if the record doesn't exist and we
@@ -525,7 +553,6 @@ int tdb_append(struct tdb_context *tdb,
                                          F_WRLCK);
                        return 0;
                }
-               /* FIXME: Check right record free? */
 
                /* Slow path. */
                newdata = malloc(key.dsize + old_dlen + dbuf.dsize);