database: Implement the match functions as callbacks

This way, we can change the easier if there is a newer version of the
database format.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

diff --git a/src/database.c b/src/database.c
index a22feda882a2a64f662a1576d5450f73d391a871..35555ac247d1fa5a99c032426fe310d31e5adce6 100644 (file)
--- a/src/database.c
+++ b/src/database.c
@@ -50,6 +50,11 @@
 #include <libloc/private.h>
 #include <libloc/stringpool.h>
 
+typedef int (*loc_database_match_as)
+       (struct loc_database* db, uint32_t number, off_t i);
+typedef int (*loc_database_match_country)
+       (struct loc_database* db, const char* code, off_t i);
+
 struct loc_database_objects {
        char* data;
        size_t length;
@@ -97,6 +102,11 @@ struct loc_database {
 
        // Countries
        struct loc_database_objects country_objects;
+
+       struct loc_database_callbacks {
+               loc_database_match_as match_as;
+               loc_database_match_country match_country;
+       } callbacks;
 };
 
 #define MAX_STACK_DEPTH 256
@@ -424,6 +434,20 @@ static int loc_database_clone_handle(struct loc_database* db, FILE* f) {
        return 0;
 }
 
+static int loc_database_match_as_v1(struct loc_database* db, uint32_t number, off_t i) {
+       struct loc_database_as_v1* as_v1 = (struct loc_database_as_v1*)loc_database_object(db,
+               &db->as_objects, sizeof(*as_v1), i);
+
+       return htobe32(as_v1->number) - number;
+}
+
+static int loc_database_match_country_v1(struct loc_database* db, const char* code, off_t i) {
+       struct loc_database_country_v1* country_v1 = \
+               (struct loc_database_country_v1*)loc_database_object(db, &db->country_objects, sizeof(*country_v1), i);
+
+       return loc_country_code_cmp(country_v1->code, code);
+}
+
 static int loc_database_open(struct loc_database* db, FILE* f) {
        int r;
 
@@ -439,6 +463,17 @@ static int loc_database_open(struct loc_database* db, FILE* f) {
        if (r)
                return r;
 
+       // Set the callbacks
+       switch (db->version) {
+               case LOC_DATABASE_VERSION_1:
+                       db->callbacks.match_as      = loc_database_match_as_v1;
+                       db->callbacks.match_country = loc_database_match_country_v1;
+                       break;
+
+               default:
+                       return -ENOTSUP;
+       }
+
        // Map the database into memory
        r = loc_database_mmap(db);
        if (r)
@@ -759,17 +794,14 @@ static int loc_database_fetch_as(struct loc_database* db, struct loc_as** as, of
        return r;
 }
 
-static int loc_database_match_as_v1(struct loc_database* db, uint32_t number, off_t i) {
-       struct loc_database_as_v1* as_v1 = (struct loc_database_as_v1*)loc_database_object(db,
-               &db->as_objects, sizeof(*as_v1), i);
-
-       return htobe32(as_v1->number) - number;
-}
-
 // Performs a binary search to find the AS in the list
 LOC_EXPORT int loc_database_get_as(struct loc_database* db, struct loc_as** as, uint32_t number) {
        int r;
 
+       // Fail if the callback has not been set
+       if (!db->callbacks.match_as)
+               return -ENOTSUP;
+
        off_t lo = 0;
        off_t hi = db->as_objects.count - 1;
 
@@ -782,7 +814,7 @@ LOC_EXPORT int loc_database_get_as(struct loc_database* db, struct loc_as** as,
                off_t i = (lo + hi) / 2;
 
                // Match the AS number
-               r = loc_database_match_as_v1(db, number, i);
+               r = db->callbacks.match_as(db, number, i);
                if (r < 0) {
                        lo = i + 1;
 
@@ -1037,13 +1069,6 @@ static int loc_database_fetch_country(struct loc_database* db,
        return r;
 }
 
-static int loc_database_match_country_v1(struct loc_database* db, const char* code, int i) {
-       struct loc_database_country_v1* country_v1 = \
-               (struct loc_database_country_v1*)loc_database_object(db, &db->country_objects, sizeof(*country_v1), i);
-
-       return loc_country_code_cmp(country_v1->code, code);
-}
-
 // Performs a binary search to find the country in the list
 LOC_EXPORT int loc_database_get_country(struct loc_database* db,
                struct loc_country** country, const char* code) {
@@ -1055,6 +1080,10 @@ LOC_EXPORT int loc_database_get_country(struct loc_database* db,
                return 1;
        }
 
+       // Fail if the callback has not been set
+       if (!db->callbacks.match_country)
+               return -ENOTSUP;
+
 #ifdef ENABLE_DEBUG
        // Save start time
        clock_t start = clock();
@@ -1067,7 +1096,7 @@ LOC_EXPORT int loc_database_get_country(struct loc_database* db,
                off_t i = (lo + hi) / 2;
 
                // Match the country code
-               r = loc_database_match_country_v1(db, code, i);
+               r = db->callbacks.match_country(db, code, i);
                if (r < 0) {
                        lo = i + 1;