database: Map the entire database into memory as a whole

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

diff --git a/src/database.c b/src/database.c
index ea058b6dcc3c8c8f313e716018743e0a1c11f827..d82e7243595c34a6747a95bbcf0afcc3a01b597a 100644 (file)
--- a/src/database.c
+++ b/src/database.c
@@ -75,6 +75,10 @@ struct loc_database {
        char* signature2;
        size_t signature2_length;
 
+       // Data mapped into memory
+       char* data;
+       off_t length;
+
        struct loc_stringpool* pool;
 
        // ASes in the database
@@ -214,6 +218,34 @@ ERROR:
        return 1;
 }
 
+/*
+       Maps the entire database into memory
+*/
+static int loc_database_mmap(struct loc_database* db) {
+       int fd = fileno(db->f);
+
+       // Determine the length of the database
+       db->length = lseek(fd, 0, SEEK_END);
+       if (db->length < 0) {
+               ERROR(db->ctx, "Could not determine the length of the database: %m\n");
+               return 1;
+       }
+
+       rewind(db->f);
+
+       // Map all data
+       db->data = mmap(NULL, db->length, PROT_READ, MAP_SHARED, fd, 0);
+       if (db->data == MAP_FAILED) {
+               ERROR(db->ctx, "Could not map the database: %m\n");
+               db->data = NULL;
+               return 1;
+       }
+
+       DEBUG(db->ctx, "Mapped database of %zu byte(s) at %p\n", db->length, db->data);
+
+       return 0;
+}
+
 /*
        Maps arbitrary objects from the database into memory.
 */
@@ -300,7 +332,7 @@ static int loc_database_read_header_v1(struct loc_database* db) {
        int r;
 
        // Read from file
-       size_t size = fread(&header, 1, sizeof(header), db->f);
+       size_t size = pread(fileno(db->f), &header, sizeof(header), sizeof(struct loc_database_magic));
 
        if (size < sizeof(header)) {
                ERROR(db->ctx, "Could not read enough data for header\n");
@@ -425,6 +457,11 @@ static int loc_database_open(struct loc_database* db, FILE* f) {
        if (r)
                return r;
 
+       // Map the database into memory
+       r = loc_database_mmap(db);
+       if (r)
+               return r;
+
        // Read the header
        r = loc_database_read_header(db);
        if (r)
@@ -439,8 +476,17 @@ static int loc_database_open(struct loc_database* db, FILE* f) {
 }
 
 static void loc_database_free(struct loc_database* db) {
+       int r;
+
        DEBUG(db->ctx, "Releasing database %p\n", db);
 
+       // Unmap the entire database
+       if (db->data) {
+               r = munmap(db->data, db->length);
+               if (r)
+                       ERROR(db->ctx, "Could not unmap the database: %m\n");
+       }
+
        // Removing all ASes
        loc_database_unmap_objects(db, &db->as_objects);