view close.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(). ]

#include "audioDB.h"
extern "C" {
#include "audioDB_API.h"
}

void audiodb_close(adb_t *adb) {
  free(adb->path);
  free(adb->header);
  close(adb->fd);
  free(adb);
}