tdb2: copy tdb1's changed expansion logic.

[ccan] / ccan / tdb / io.c

diff --git a/ccan/tdb/io.c b/ccan/tdb/io.c
index 929290c1407b092ab2b4eb38ca704efbf450cd75..77f26adfe7df3eace208dee00f3f57aeaa1d28f0 100644 (file)
--- a/ccan/tdb/io.c
+++ b/ccan/tdb/io.c
@@ -125,9 +125,17 @@ static int tdb_write(struct tdb_context *tdb, tdb_off_t off,
 /* Endian conversion: we only ever deal with 4 byte quantities */
 void *tdb_convert(void *buf, uint32_t size)
 {
-       uint32_t i, *p = (uint32_t *)buf;
-       for (i = 0; i < size / 4; i++)
-               p[i] = TDB_BYTEREV(p[i]);
+       uint32_t i;
+       unsigned char *p = buf, tmp;
+
+       for (i = 0; i < size; i += 4) {
+               tmp = p[i];
+               p[i] = p[i+3];
+               p[i+3] = tmp;
+               tmp = p[i+1];
+               p[i+1] = p[i+2];
+               p[i+2] = tmp;
+       }
        return buf;
 }
 
@@ -194,7 +202,9 @@ int tdb_munmap(struct tdb_context *tdb)
 
 #if HAVE_MMAP
        if (tdb->map_ptr) {
-               int ret = munmap(tdb->map_ptr, tdb->map_size);
+               int ret;
+
+               ret = munmap(tdb->map_ptr, tdb->map_size);
                if (ret != 0)
                        return ret;
        }
@@ -293,13 +303,39 @@ static int tdb_expand_file(struct tdb_context *tdb, tdb_off_t size, tdb_off_t ad
        return 0;
 }
 
+/* You need 'size', this tells you how much you should expand by. */
+tdb_off_t tdb_expand_adjust(tdb_off_t map_size, tdb_off_t size, int page_size)
+{
+       tdb_off_t new_size, top_size;
+
+       /* limit size in order to avoid using up huge amounts of memory for
+        * in memory tdbs if an oddball huge record creeps in */
+       if (size > 100 * 1024) {
+               top_size = map_size + size * 2;
+       } else {
+               top_size = map_size + size * 100;
+       }
+
+       /* always make room for at least top_size more records, and at
+          least 25% more space. if the DB is smaller than 100MiB,
+          otherwise grow it by 10% only. */
+       if (map_size > 100 * 1024 * 1024) {
+               new_size = map_size * 1.10;
+       } else {
+               new_size = map_size * 1.25;
+       }
+
+       /* Round the database up to a multiple of the page size */
+       new_size = MAX(top_size, new_size);
+       return TDB_ALIGN(new_size, page_size) - map_size;
+}
 
 /* expand the database at least size bytes by expanding the underlying
    file and doing the mmap again if necessary */
 int tdb_expand(struct tdb_context *tdb, tdb_off_t size)
 {
        struct tdb_record rec;
-       tdb_off_t offset, new_size;     
+       tdb_off_t offset;
 
        if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
                TDB_LOG((tdb, TDB_DEBUG_ERROR, "lock failed in tdb_expand\n"));
@@ -309,11 +345,7 @@ int tdb_expand(struct tdb_context *tdb, tdb_off_t size)
        /* must know about any previous expansions by another process */
        tdb->methods->tdb_oob(tdb, tdb->map_size + 1, 1);
 
-       /* always make room for at least 100 more records, and at
-           least 25% more space. Round the database up to a multiple
-           of the page size */
-       new_size = MAX(tdb->map_size + size*100, tdb->map_size * 1.25);
-       size = TDB_ALIGN(new_size, tdb->page_size) - tdb->map_size;
+       size = tdb_expand_adjust(tdb->map_size, size, tdb->page_size);
 
        if (!(tdb->flags & TDB_INTERNAL))
                tdb_munmap(tdb);
@@ -386,6 +418,7 @@ unsigned char *tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_len
        unsigned char *buf;
 
        /* some systems don't like zero length malloc */
+
        if (!(buf = (unsigned char *)malloc(len ? len : 1))) {
                /* Ensure ecode is set for log fn. */
                tdb->ecode = TDB_ERR_OOM;
@@ -460,8 +493,6 @@ static const struct tdb_methods io_methods = {
        tdb_next_hash_chain,
        tdb_oob,
        tdb_expand_file,
-       tdb_brlock,
-       tdb_brunlock
 };
 
 /*