database: Add function to align to page boundaries

[people/ms/libloc.git] / src / database.c

diff --git a/src/database.c b/src/database.c
index 928ed8569f4c65634baf2b7de326a0a3f060eec7..a263d0270dba16d422ea28e85d52fa49f800847f 100644 (file)
--- a/src/database.c
+++ b/src/database.c
@@ -346,6 +346,12 @@ static void loc_database_make_magic(struct loc_database* db, struct loc_database
        magic->version = htons(LOC_DATABASE_VERSION);
 }
 
+static void loc_database_align_page_boundary(off_t* offset, FILE* f) {
+       // Move to next page boundary
+       while (*offset % LOC_DATABASE_PAGE_SIZE > 0)
+               *offset += fwrite("", 1, 1, f);
+}
+
 static int loc_database_write_pool(struct loc_database* db, struct loc_database_header_v0* header, off_t* offset, FILE* f) {
        // Save the offset of the pool section
        DEBUG(db->ctx, "Pool starts at %jd bytes\n", *offset);
@@ -361,6 +367,29 @@ static int loc_database_write_pool(struct loc_database* db, struct loc_database_
        return 0;
 }
 
+static int loc_database_write_as_section(struct loc_database* db,
+               struct loc_database_header_v0* header, off_t* offset, FILE* f) {
+       DEBUG(db->ctx, "AS section starts at %jd bytes\n", *offset);
+       header->as_offset = htonl(*offset);
+
+       size_t as_length = 0;
+
+       struct loc_database_as_v0 dbas;
+       for (unsigned int i = 0; i < db->as_count; i++) {
+               // Convert AS into database format
+               loc_as_to_database_v0(db->as[i], &dbas);
+
+               // Write to disk
+               offset += fwrite(&dbas, 1, sizeof(dbas), f);
+               as_length += sizeof(dbas);
+       }
+
+       DEBUG(db->ctx, "AS section has a length of %zu bytes\n", as_length);
+       header->as_length = htonl(as_length);
+
+       return 0;
+}
+
 LOC_EXPORT int loc_database_write(struct loc_database* db, FILE* f) {
        struct loc_database_magic magic;
        loc_database_make_magic(db, &magic);
@@ -389,27 +418,19 @@ LOC_EXPORT int loc_database_write(struct loc_database* db, FILE* f) {
        }
        offset += sizeof(header);
 
-       // Move to next page boundary
-       while (offset % LOC_DATABASE_PAGE_SIZE > 0)
-               offset += fwrite("", 1, 1, f);
+       loc_database_align_page_boundary(&offset, f);
 
        // Write pool
        r = loc_database_write_pool(db, &header, &offset, f);
        if (r)
                return r;
 
-       // Write all ASes
-       header.as_offset = htonl(offset);
+       loc_database_align_page_boundary(&offset, f);
 
-       struct loc_database_as_v0 dbas;
-       for (unsigned int i = 0; i < db->as_count; i++) {
-               // Convert AS into database format
-               loc_as_to_database_v0(db->as[i], &dbas);
-
-               // Write to disk
-               offset += fwrite(&dbas, 1, sizeof(dbas), f);
-       }
-       header.as_length = htonl(db->as_count * sizeof(dbas));
+       // Write all ASes
+       r = loc_database_write_as_section(db, &header, &offset, f);
+       if (r)
+               return r;
 
        // Write the header
        r = fseek(f, sizeof(magic), SEEK_SET);