* 10485760 bytes. The size of the memory map is also the maximum size
* of the database. The value should be chosen as large as possible,
* to accommodate future growth of the database.
- * This function may only be called after #mdb_env_create() and before #mdb_env_open().
- * The size may be changed by closing and reopening the environment.
+ * This function should be called after #mdb_env_create() and before #mdb_env_open().
+ * It may be called at later times if no transactions are active in
+ * this process. Note that the library does not check for this condition,
+ * the caller must ensure it explicitly.
+ *
+ * If the mapsize is changed by another process, #mdb_txn_begin() will
+ * return #MDB_MAP_RESIZED. This function may be called with a size
+ * of zero to adopt the new size.
+ *
* Any attempt to set a size smaller than the space already consumed
* by the environment will be silently changed to the current size of the used space.
* @param[in] env An environment handle returned by #mdb_env_create()
* @return A non-zero error value on failure and 0 on success. Some possible
* errors are:
* <ul>
- * <li>EINVAL - an invalid parameter was specified, or the environment is already open.
+ * <li>EINVAL - an invalid parameter was specified, or the environment has
+ * an active write transaction.
* </ul>
*/
int mdb_env_set_mapsize(MDB_env *env, size_t size);
* <li>#MDB_PANIC - a fatal error occurred earlier and the environment
* must be shut down.
* <li>#MDB_MAP_RESIZED - another process wrote data beyond this MDB_env's
- * mapsize and the environment must be shut down.
+ * mapsize and this environment's map must be resized as well.
+ * See #mdb_env_set_mapsize().
* <li>#MDB_READERS_FULL - a read-only transaction was requested and
* the reader lock table is full. See #mdb_env_set_maxreaders().
* <li>ENOMEM - out of memory.
DPUTS("writing new meta page");
- GET_PAGESIZE(psize);
+ psize = env->me_psize;
meta->mm_magic = MDB_MAGIC;
meta->mm_version = MDB_DATA_VERSION;
return MDB_SUCCESS;
}
+static int
+mdb_env_map(MDB_env *env, void *addr, int newsize)
+{
+ MDB_page *p;
+ unsigned int flags = env->me_flags;
+#ifdef _WIN32
+ int rc;
+ HANDLE mh;
+ LONG sizelo, sizehi;
+ sizelo = env->me_mapsize & 0xffffffff;
+ sizehi = env->me_mapsize >> 16 >> 16; /* only needed on Win64 */
+
+ /* Windows won't create mappings for zero length files.
+ * Just allocate the maxsize right now.
+ */
+ if (newsize) {
+ if (SetFilePointer(env->me_fd, sizelo, &sizehi, 0) != (DWORD)sizelo
+ || !SetEndOfFile(env->me_fd)
+ || SetFilePointer(env->me_fd, 0, NULL, 0) != 0)
+ return ErrCode();
+ }
+ mh = CreateFileMapping(env->me_fd, NULL, flags & MDB_WRITEMAP ?
+ PAGE_READWRITE : PAGE_READONLY,
+ sizehi, sizelo, NULL);
+ if (!mh)
+ return ErrCode();
+ env->me_map = MapViewOfFileEx(mh, flags & MDB_WRITEMAP ?
+ FILE_MAP_WRITE : FILE_MAP_READ,
+ 0, 0, env->me_mapsize, addr);
+ rc = env->me_map ? 0 : ErrCode();
+ CloseHandle(mh);
+ if (rc)
+ return rc;
+#else
+ int prot = PROT_READ;
+ if (flags & MDB_WRITEMAP) {
+ prot |= PROT_WRITE;
+ if (newsize && ftruncate(env->me_fd, env->me_mapsize) < 0)
+ return ErrCode();
+ }
+ env->me_map = mmap(addr, env->me_mapsize, prot, MAP_SHARED,
+ env->me_fd, 0);
+ if (env->me_map == MAP_FAILED) {
+ env->me_map = NULL;
+ return ErrCode();
+ }
+ /* Turn off readahead. It's harmful when the DB is larger than RAM. */
+#ifdef MADV_RANDOM
+ madvise(env->me_map, env->me_mapsize, MADV_RANDOM);
+#else
+#ifdef POSIX_MADV_RANDOM
+ posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM);
+#endif /* POSIX_MADV_RANDOM */
+#endif /* MADV_RANDOM */
+#endif /* _WIN32 */
+
+ /* Can happen because the address argument to mmap() is just a
+ * hint. mmap() can pick another, e.g. if the range is in use.
+ * The MAP_FIXED flag would prevent that, but then mmap could
+ * instead unmap existing pages to make room for the new map.
+ */
+ if (addr && env->me_map != addr)
+ return EBUSY; /* TODO: Make a new MDB_* error code? */
+
+ p = (MDB_page *)env->me_map;
+ env->me_metas[0] = METADATA(p);
+ env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + env->me_psize);
+
+ return MDB_SUCCESS;
+}
+
int
mdb_env_set_mapsize(MDB_env *env, size_t size)
{
- if (env->me_map)
- return EINVAL;
+ /* If env is already open, caller is responsible for making
+ * sure there are no active txns.
+ */
+ if (env->me_map) {
+ int rc;
+ void *old;
+ if (env->me_txn)
+ return EINVAL;
+ if (!size)
+ size = env->me_metas[mdb_env_pick_meta(env)]->mm_mapsize;
+ munmap(env->me_map, env->me_mapsize);
+ env->me_mapsize = size;
+ old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL;
+ rc = mdb_env_map(env, old, 1);
+ if (rc)
+ return rc;
+ }
env->me_mapsize = size;
if (env->me_psize)
env->me_maxpg = env->me_mapsize / env->me_psize;
mdb_env_open2(MDB_env *env)
{
unsigned int flags = env->me_flags;
- int i, newenv = 0;
+ int i, newenv = 0, rc;
MDB_meta meta;
- MDB_page *p;
-#ifndef _WIN32
- int prot;
-#endif
+
+#ifdef _WIN32
+ /* See if we should use QueryLimited */
+ rc = GetVersion();
+ if ((rc & 0xff) > 5)
+ env->me_pidquery = MDB_PROCESS_QUERY_LIMITED_INFORMATION;
+ else
+ env->me_pidquery = PROCESS_QUERY_INFORMATION;
+#endif /* _WIN32 */
memset(&meta, 0, sizeof(meta));
return i;
DPUTS("new mdbenv");
newenv = 1;
+ GET_PAGESIZE(env->me_psize);
+ } else {
+ env->me_psize = meta.mm_psize;
}
/* Was a mapsize configured? */
env->me_mapsize = minsize;
}
-#ifdef _WIN32
- {
- int rc;
- HANDLE mh;
- LONG sizelo, sizehi;
- sizelo = env->me_mapsize & 0xffffffff;
- sizehi = env->me_mapsize >> 16 >> 16; /* only needed on Win64 */
-
- /* See if we should use QueryLimited */
- rc = GetVersion();
- if ((rc & 0xff) > 5)
- env->me_pidquery = MDB_PROCESS_QUERY_LIMITED_INFORMATION;
- else
- env->me_pidquery = PROCESS_QUERY_INFORMATION;
-
- /* Windows won't create mappings for zero length files.
- * Just allocate the maxsize right now.
- */
- if (newenv) {
- if (SetFilePointer(env->me_fd, sizelo, &sizehi, 0) != (DWORD)sizelo
- || !SetEndOfFile(env->me_fd)
- || SetFilePointer(env->me_fd, 0, NULL, 0) != 0)
- return ErrCode();
- }
- mh = CreateFileMapping(env->me_fd, NULL, flags & MDB_WRITEMAP ?
- PAGE_READWRITE : PAGE_READONLY,
- sizehi, sizelo, NULL);
- if (!mh)
- return ErrCode();
- env->me_map = MapViewOfFileEx(mh, flags & MDB_WRITEMAP ?
- FILE_MAP_WRITE : FILE_MAP_READ,
- 0, 0, env->me_mapsize, meta.mm_address);
- rc = env->me_map ? 0 : ErrCode();
- CloseHandle(mh);
- if (rc)
- return rc;
- }
-#else
- i = MAP_SHARED;
- prot = PROT_READ;
- if (flags & MDB_WRITEMAP) {
- prot |= PROT_WRITE;
- if (ftruncate(env->me_fd, env->me_mapsize) < 0)
- return ErrCode();
- }
- env->me_map = mmap(meta.mm_address, env->me_mapsize, prot, i,
- env->me_fd, 0);
- if (env->me_map == MAP_FAILED) {
- env->me_map = NULL;
- return ErrCode();
- }
- /* Turn off readahead. It's harmful when the DB is larger than RAM. */
-#ifdef MADV_RANDOM
- madvise(env->me_map, env->me_mapsize, MADV_RANDOM);
-#else
-#ifdef POSIX_MADV_RANDOM
- posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM);
-#endif /* POSIX_MADV_RANDOM */
-#endif /* MADV_RANDOM */
-#endif /* _WIN32 */
+ rc = mdb_env_map(env, meta.mm_address, newenv);
+ if (rc)
+ return rc;
if (newenv) {
if (flags & MDB_FIXEDMAP)
if (i != MDB_SUCCESS) {
return i;
}
- } else if (meta.mm_address && env->me_map != meta.mm_address) {
- /* Can happen because the address argument to mmap() is just a
- * hint. mmap() can pick another, e.g. if the range is in use.
- * The MAP_FIXED flag would prevent that, but then mmap could
- * instead unmap existing pages to make room for the new map.
- */
- return EBUSY; /* TODO: Make a new MDB_* error code? */
}
- env->me_psize = meta.mm_psize;
env->me_maxfree_1pg = (env->me_psize - PAGEHDRSZ) / sizeof(pgno_t) - 1;
env->me_nodemax = (env->me_psize - PAGEHDRSZ) / MDB_MINKEYS;
env->me_maxpg = env->me_mapsize / env->me_psize;
-
- p = (MDB_page *)env->me_map;
- env->me_metas[0] = METADATA(p);
- env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + meta.mm_psize);
-
#if MDB_DEBUG
{
int toggle = mdb_env_pick_meta(env);
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