diff create.cpp @ 392:78fed0d4c108 api-inversion

Include some necessary information in struct adb.

Now the struct adb contains a database fd, the flags used to open that
fd (so that we can later tell if it was for write or not) and a database
header pointer.

audiodb_open() is now responsible for filling in all of that
information.  To do that, it needs to take an open(2) flag; that's good,
because it means that the call to open(2) is no longer invoking
undefined behaviour.  (Also, the previous version of audiodb_open()
leaked an fd).  Unfortunately, that means we have broken ABI and API
compatibility.  (Fortunately, we have fewer than 12 users).

Use audiodb_open() in audioDB::initDBHeader().

We've temporarily(?) put acquire_lock(int, bool) in the API header; that
means we need to include <stdbool.h> and compile C files with -std=c99.
Do so.

Make audiodb_close() free resources allocated by audiodb_open().

Include a struct adb * field in the audioDB C++ object...
... which lets us actually implement memory-correctness, by
audiodb_close()ing the database in audioDB::cleanup().

[ The lock is, I think, correctly disposed of; man fcntl(2) on Linux
  says that the locks are released once any file descriptor relating to
  the file is closed, and we close the fd in audiodb_close(). ]

--- a/create.cpp	Mon Nov 24 12:50:38 2008 +0000
+++ b/create.cpp	Mon Nov 24 15:42:15 2008 +0000
@@ -27,8 +27,6 @@
 
 */
 
-int acquire_lock(int, bool);
-
 extern "C" {
   adb_t *audiodb_create(const char *path, unsigned datasize, unsigned ntracks, unsigned datadim) {
     int fd;
@@ -120,7 +118,7 @@
     }
 
     free(header);
-    return audiodb_open(path);
+    return audiodb_open(path, O_RDWR);
 
   error:
     if(header) {