bool
LFLock_Request_IMP(LockFileLock *self) {
LockFileLockIVARS *const ivars = LFLock_IVARS(self);
bool success = false;
if (Folder_Exists(ivars->folder, ivars->lock_path)) {
Err_set_error((Err*)LockErr_new(Str_newf("Can't obtain lock: '%o' exists",
ivars->lock_path)));
return false;
}
// Create the "locks" subdirectory if necessary.
String *lock_dir_name = SSTR_WRAP_C("locks");
if (!Folder_Exists(ivars->folder, lock_dir_name)) {
if (!Folder_MkDir(ivars->folder, lock_dir_name)) {
Err *mkdir_err = (Err*)CERTIFY(Err_get_error(), ERR);
LockErr *err = LockErr_new(Str_newf("Can't create 'locks' directory: %o",
Err_Get_Mess(mkdir_err)));
// Maybe our attempt failed because another process succeeded.
if (Folder_Find_Folder(ivars->folder, lock_dir_name)) {
DECREF(err);
}
else {
// Nope, everything failed, so bail out.
Err_set_error((Err*)err);
return false;
}
}
}
// Prepare to write pid, lock name, and host to the lock file as JSON.
Hash *file_data = Hash_new(3);
Hash_Store_Utf8(file_data, "pid", 3,
(Obj*)Str_newf("%i32", (int32_t)PID_getpid()));
Hash_Store_Utf8(file_data, "host", 4, INCREF(ivars->host));
Hash_Store_Utf8(file_data, "name", 4, INCREF(ivars->name));
String *json = Json_to_json((Obj*)file_data);
DECREF(file_data);
// Write to a temporary file, then use the creation of a hard link to
// ensure atomic but non-destructive creation of the lockfile with its
// complete contents.
OutStream *outstream = Folder_Open_Out(ivars->folder, ivars->link_path);
if (!outstream) {
ERR_ADD_FRAME(Err_get_error());
DECREF(json);
return false;
}
struct lockfile_context context;
context.outstream = outstream;
context.json = json;
Err *json_error = Err_trap(S_write_lockfile_json, &context);
bool wrote_json = !json_error;
DECREF(outstream);
DECREF(json);
if (wrote_json) {
success = Folder_Hard_Link(ivars->folder, ivars->link_path,
ivars->lock_path);
if (!success) {
Err *hard_link_err = (Err*)CERTIFY(Err_get_error(), ERR);
Err_set_error((Err*)LockErr_new(Str_newf("Failed to obtain lock at '%o': %o",
ivars->lock_path,
Err_Get_Mess(hard_link_err))));
}
}
else {
Err_set_error((Err*)LockErr_new(Str_newf("Failed to obtain lock at '%o': %o",
ivars->lock_path,
Err_Get_Mess(json_error))));
DECREF(json_error);
}
// Verify that our temporary file got zapped.
bool deletion_failed = !Folder_Delete(ivars->folder, ivars->link_path);
if (deletion_failed) {
String *mess = MAKE_MESS("Failed to delete '%o'", ivars->link_path);
Err_throw_mess(ERR, mess);
}
return success;
}
bool
IxManager_Remove_Merge_Data_IMP(IndexManager *self) {
IndexManagerIVARS *const ivars = IxManager_IVARS(self);
String *merge_json = SSTR_WRAP_C("merge.json");
return Folder_Delete(ivars->folder, merge_json) != 0;
}
