tier/libgfdb: Replacing ASCII query file with binary

Earlier, when the database was queried we used to save
all the queried records in an ASCII format in the query file.
This caused issues like filename having ASCII delimiter and used
to take a lot of space. The tier.c file also had a lot of parsing code.

Here we changed the format of the query file to binary.
All the logic of serialization and formating of query record is done
by libgfdb. Libgfdb provides API,
gfdb_write_query_record() and gfdb_read_query_record(),
which the user i.e tier migrator and CTR xlator can use to
write to and read from query file.
With this binary format we save on disk space i.e reduce to 50% atleast
as we are saving GFID's in binary format 16 bytes and not the string format
which takes 36 bytes + We are not saving path of the file + we are also saving on
ASCII delimiters.

The on disk format of query record is as follows,

+---------------------------------------------------------------------------+
| Length of serialized query record |       Serialized Query Record         |
+---------------------------------------------------------------------------+
             4 bytes                     Length of serialized query record
                                                      |
                                                      |
     -------------------------------------------------|
     |
     |
     V
   Serialized Query Record Format:
   +---------------------------------------------------------------------------+
   | GFID |  Link count   |  <LINK INFO>  |.....                      | FOOTER |
   +---------------------------------------------------------------------------+
     16 B        4 B         Link Length                                  4 B
                                |                                          |
                                |                                          |
   -----------------------------|                                          |
   |                                                                       |
   |                                                                       |
   V                                                                       |
   Each <Link Info> will be serialized as                                  |
   +-----------------------------------------------+                       |
   | PGID | BASE_NAME_LENGTH |      BASE_NAME      |                       |
   +-----------------------------------------------+                       |
     16 B       4 B             BASE_NAME_LENGTH                           |
                                                                           |
                                                                           |
   ------------------------------------------------------------------------|
   |
   |
   V
   FOOTER is a magic number 0xBAADF00D indicating the end of the record.
   This also serves as a serialized schema validator.

Backport of http://review.gluster.org/#/c/12354/

> Change-Id: I9db7416fd421e118dd44eafab8b535caafe50d5a
> BUG: 1272207
> Signed-off-by: Joseph Fernandes <josferna@redhat.com>
> Reviewed-on: http://review.gluster.org/12354
> Reviewed-by: N Balachandran <nbalacha@redhat.com>
> Tested-by: Gluster Build System <jenkins@build.gluster.com>
> Reviewed-by: Dan Lambright <dlambrig@redhat.com>
> Tested-by: Dan Lambright <dlambrig@redhat.com>

Change-Id: I170c579027f2594a58706f826e3ddf89e34022f4
BUG: 1263619
Signed-off-by: Joseph Fernandes <josferna@redhat.com>
Reviewed-on: http://review.gluster.org/12535
Tested-by: NetBSD Build System <jenkins@build.gluster.org>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Dan Lambright <dlambrig@redhat.com>
Tested-by: Dan Lambright <dlambrig@redhat.com>

2 files changed, 16 insertions, 11 deletions

diff --git a/xlators/features/changetimerecorder/src/changetimerecorder.c b/xlators/features/changetimerecorder/src/changetimerecorder.c
index fb337674937..c4634c16ee3 100644
--- a/xlators/features/changetimerecorder/src/changetimerecorder.c
+++ b/xlators/features/changetimerecorder/src/changetimerecorder.c
@@ -1386,15 +1386,18 @@ static int
 ctr_db_query_callback (gfdb_query_record_t *gfdb_query_record,
                         void *args) {
         int ret = -1;
-        char gfid_str[UUID_CANONICAL_FORM_LEN+1] = "";
         ctr_query_cbk_args_t *query_cbk_args = args;
 
         GF_VALIDATE_OR_GOTO ("ctr", query_cbk_args, out);
 
-        gf_uuid_unparse (gfdb_query_record->gfid, gfid_str);
-        fprintf (query_cbk_args->queryFILE, "%s|%s|%ld\n", gfid_str,
-                 gfdb_query_record->_link_info_str,
-                 gfdb_query_record->link_info_size);
+        ret = gfdb_write_query_record (query_cbk_args->query_fd,
+                                       gfdb_query_record);
+        if (ret) {
+                gf_msg ("ctr", GF_LOG_ERROR, 0,
+                        CTR_MSG_FATAL_ERROR,
+                        "Failed to write to query file");
+                goto out;
+        }
 
         query_cbk_args->count++;
 
@@ -1429,8 +1432,10 @@ ctr_db_query (xlator_t *this,
         GF_VALIDATE_OR_GOTO (this->name, ipc_ctr_params, out);
 
         /*Query for eligible files from db*/
-        query_cbk_args.queryFILE = fopen(query_file, "a+");
-        if (!query_cbk_args.queryFILE) {
+        query_cbk_args.query_fd = open (query_file,
+                        O_WRONLY | O_CREAT | O_APPEND,
+                        S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
+        if (query_cbk_args.query_fd < 0) {
                 gf_msg (this->name, GF_LOG_ERROR, errno,
                         CTR_MSG_FATAL_ERROR,
                         "Failed to open query file %s", query_file);
@@ -1494,9 +1499,9 @@ out:
         if (!ret)
                 ret = query_cbk_args.count;
 
-        if (query_cbk_args.queryFILE) {
-                fclose (query_cbk_args.queryFILE);
-                query_cbk_args.queryFILE = NULL;
+        if (query_cbk_args.query_fd >= 0) {
+                close (query_cbk_args.query_fd);
+                query_cbk_args.query_fd = -1;
         }
 
         return ret;
diff --git a/xlators/features/changetimerecorder/src/ctr-helper.h b/xlators/features/changetimerecorder/src/ctr-helper.h
index 654607fb852..e833c872881 100644
--- a/xlators/features/changetimerecorder/src/ctr-helper.h
+++ b/xlators/features/changetimerecorder/src/ctr-helper.h
@@ -37,7 +37,7 @@
 
 
 typedef struct ctr_query_cbk_args {
-        FILE *queryFILE;
+        int query_fd;
         int count;
 } ctr_query_cbk_args_t;