SoW-2019-0002: Dynamic Snapshot

[lttng-tools.git] / src / common / snapshot.c

diff --git a/src/common/snapshot.c b/src/common/snapshot.c
new file mode 100644 (file)
index 0000000..2879f0f
--- /dev/null
+++ b/src/common/snapshot.c
@@ -0,0 +1,184 @@
+/*
+ * Copyright (C) 2020 - EfficiOS, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "buffer-view.h"
+#include "dynamic-buffer.h"
+#include "lttng/snapshot.h"
+#include "lttng/snapshot-internal.h"
+#include "snapshot.h"
+
+#include <assert.h>
+#include <stdlib.h>
+
+LTTNG_HIDDEN
+bool lttng_snapshot_output_validate(const struct lttng_snapshot_output *output)
+{
+       bool valid = false;
+       size_t len;
+
+       /*
+        * It is mandatory to have a ctrl_url.  If there is only one output
+        * URL (in the net://, net6:// or file:// form), it will be in this
+        * field.
+        */
+       len = lttng_strnlen(output->ctrl_url, sizeof(output->ctrl_url));
+       if (len == 0 || len >= sizeof(output->ctrl_url)) {
+               goto end;
+       }
+
+       len = lttng_strnlen(output->data_url, sizeof(output->data_url));
+       if (len >= sizeof(output->data_url)) {
+               goto end;
+       }
+
+       len = lttng_strnlen(output->name, sizeof(output->name));
+       if (len >= sizeof(output->name)) {
+               goto end;
+       }
+
+       valid = true;
+
+end:
+       return valid;
+}
+
+LTTNG_HIDDEN
+bool lttng_snapshot_output_is_equal(
+               const struct lttng_snapshot_output *a,
+               const struct lttng_snapshot_output *b)
+{
+       bool equal = false;
+
+       assert(a);
+       assert(b);
+
+       if (a->max_size != b->max_size) {
+               goto end;
+       }
+
+       if (strcmp(a->name, b->name) != 0) {
+               goto end;
+       }
+
+       if (strcmp(a->ctrl_url, b->ctrl_url) != 0) {
+               goto end;
+       }
+
+       if (strcmp(a->data_url, b->data_url) != 0) {
+               goto end;
+       }
+
+       equal = true;
+
+end:
+       return equal;
+}
+
+/*
+ * This is essentially the same as `struct lttng_snapshot_output`, but packed.
+ */
+struct LTTNG_PACKED lttng_snapshot_output_comm {
+       uint32_t id;
+       uint64_t max_size;
+       char name[LTTNG_NAME_MAX];
+       char ctrl_url[PATH_MAX];
+       char data_url[PATH_MAX];
+};
+
+LTTNG_HIDDEN
+int lttng_snapshot_output_serialize(
+               const struct lttng_snapshot_output *output,
+               struct lttng_dynamic_buffer *buf)
+{
+       struct lttng_snapshot_output_comm comm;
+       int ret;
+
+       comm.id = output->id;
+       comm.max_size = output->max_size;
+
+       ret = lttng_strncpy(comm.name, output->name, sizeof(comm.name));
+       if (ret) {
+               goto end;
+       }
+
+       ret = lttng_strncpy(comm.ctrl_url, output->ctrl_url, sizeof(comm.ctrl_url));
+       if (ret) {
+               goto end;
+       }
+
+       ret = lttng_strncpy(comm.data_url, output->data_url, sizeof(comm.data_url));
+       if (ret) {
+               goto end;
+       }
+
+       ret = lttng_dynamic_buffer_append(buf, &comm, sizeof(comm));
+       if (ret) {
+               goto end;
+       }
+
+end:
+       return ret;
+}
+
+LTTNG_HIDDEN
+ssize_t lttng_snapshot_output_create_from_buffer(
+               const struct lttng_buffer_view *view,
+               struct lttng_snapshot_output **output_p)
+{
+       const struct lttng_snapshot_output_comm *comm;
+       struct lttng_snapshot_output *output = NULL;
+       int ret;
+
+       if (view->size != sizeof(*comm)) {
+               ret = -1;
+               goto end;
+       }
+
+       output = lttng_snapshot_output_create();
+       if (!output) {
+               ret = -1;
+               goto end;
+       }
+
+       comm = (struct lttng_snapshot_output_comm *) view->data;
+
+       output->id = comm->id;
+       output->max_size = comm->max_size;
+
+       ret = lttng_strncpy(output->name, comm->name, sizeof(output->name));
+       if (ret) {
+               goto end;
+       }
+
+       ret = lttng_strncpy(output->ctrl_url, comm->ctrl_url, sizeof(output->ctrl_url));
+       if (ret) {
+               goto end;
+       }
+
+       ret = lttng_strncpy(output->data_url, comm->data_url, sizeof(output->data_url));
+       if (ret) {
+               goto end;
+       }
+
+       *output_p = output;
+       output = NULL;
+       ret = sizeof(*comm);
+
+end:
+       lttng_snapshot_output_destroy(output);
+       return ret;
+}