Feature lmdb as caching backend (#309)

* * first version of lmdb support
* TODOs: remove LMDB=1 from source and set it in configure.ac

* ~ max db size 512MB

* lmdb: move to seperate source file and fix configure

configure.ac

@@ -355,9 +355,23 @@ DBLINKED=0
 DBLIB=""
 
 AC_ARG_ENABLE(db, [AC_HELP_STRING([--disable-db], [disable Berkeley DB (default=try to detect DB)])],[enable_db=$enableval],[enable_db=yes])
+AC_ARG_ENABLE(lmdb, [AC_HELP_STRING([--enable-lmdb], [enable lmdb as cache DB instead of BerkeleyDB (default=disable)])],[enable_lmdb=$enableval],[enable_lmdb=no])
 
+if test "x$enable_lmdb" = "xyes"; then
+   AC_CHECK_HEADER(lmdb.h, [LMDB="yes"])
+   if test "x$LMDB" = "x"; then
+     AC_MSG_WARN(lmdb.h not found cache support disabled)
+   else
+     AC_CHECK_LIB(lmdb, mdb_env_create, [DBLIB="-llmdb"; DBLINKED=1], [])
+     if test "$DBLINKED" = 1; then
+       AC_DEFINE([LMDB], [1], [Enable support for lmdb cache])
+       enable_db="no"
+     else
+       AC_MSG_WARN(liblmdb not found cache support disabled)
+     fi
+   fi
 dnl Check for a presence of Berkeley DB header
-if test "x$enable_db" != "xyes"; then
+elif test "x$enable_db" != "xyes"; then
    AC_MSG_WARN(cache support disabled)
 else
    AC_CHECK_HEADER(db.h, [DB_HEADER=1], [DB_HEADER=0])

src/data-types/Makefile.am

@@ -47,7 +47,7 @@ libdata_types_la_SOURCES = connect.h connect.c base64.h hmac-md5.h	\
 	mailstream_low.c mailstream.c mailstream_socket.c		\
 	mailstream_ssl.c carray.c clist.c chash.c		        \
 	charconv.c maillock.c base64.c mail_cache_db_types.h		\
-	mail_cache_db.h mail_cache_db.c mailsem.c mailsasl.h		\
+	mail_cache_db.h mail_cache_db.c mail_cache_lmdb.c mailsem.c mailsasl.h		\
 	mailsasl.c mailstream_cancel_types.h mailstream_cancel.h	\
 	mailstream_cancel.c timeutils.h timeutils.c			\
 	mmapstring_private.h mailstream_ssl_private.h			\

src/data-types/mail_cache_db.c

@@ -37,6 +37,8 @@
 #	include <config.h>
 #endif
 
+#ifndef LMDB
+
 #include "mail_cache_db.h"
 
 #include <sys/types.h>
@@ -498,3 +500,5 @@ int mail_cache_db_get_keys(struct mail_cache_db * cache_db,
   return -1;
 }
 #endif
+
+#endif