1 files changed, 20 insertions, 0 deletions
diff --git a/src/os.c b/src/os.c
index b5e918a..be2ea4c 100644
--- a/src/os.c
+++ b/src/os.c
@@ -141,6 +141,26 @@ int sqlite3OsShmMap(
   return id->pMethods->xShmMap(id, iPage, pgsz, bExtend, pp);
 }
 
+#if SQLITE_MAX_MMAP_SIZE>0
+/* The real implementation of xFetch and xUnfetch */
+int sqlite3OsFetch(sqlite3_file *id, i64 iOff, int iAmt, void **pp){
+  DO_OS_MALLOC_TEST(id);
+  return id->pMethods->xFetch(id, iOff, iAmt, pp);
+}
+int sqlite3OsUnfetch(sqlite3_file *id, i64 iOff, void *p){
+  return id->pMethods->xUnfetch(id, iOff, p);
+}
+#else
+/* No-op stubs to use when memory-mapped I/O is disabled */
+int sqlite3OsFetch(sqlite3_file *id, i64 iOff, int iAmt, void **pp){
+  *pp = 0;
+  return SQLITE_OK;
+}
+int sqlite3OsUnfetch(sqlite3_file *id, i64 iOff, void *p){
+  return SQLITE_OK;
+}
+#endif
+
 /*
 ** The next group of routines are convenience wrappers around the
 ** VFS methods.