On-disk multiple tracefiles circular buffer

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

diff --git a/src/common/consumer.c b/src/common/consumer.c
index 5f87f4b5018fbec1a2de542797f46b4f6d17475f..b6e440a486fc5995f9a7caca0eac39631bf3340c 100644 (file)
--- a/src/common/consumer.c
+++ b/src/common/consumer.c
@@ -828,7 +828,9 @@ struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key,
                uid_t uid,
                gid_t gid,
                int relayd_id,
-               enum lttng_event_output output)
+               enum lttng_event_output output,
+               uint64_t tracefile_size,
+               uint64_t tracefile_count)
 {
        struct lttng_consumer_channel *channel;
 
@@ -845,6 +847,8 @@ struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key,
        channel->gid = gid;
        channel->relayd_id = relayd_id;
        channel->output = output;
+       channel->tracefile_size = tracefile_size;
+       channel->tracefile_count = tracefile_count;
 
        strncpy(channel->pathname, pathname, sizeof(channel->pathname));
        channel->pathname[sizeof(channel->pathname) - 1] = '\0';
@@ -1283,6 +1287,93 @@ end:
        return ret;
 }
 
+/*
+ * Create the tracefile on disk.
+ *
+ * Return 0 on success or else a negative value.
+ */
+int lttng_create_output_file(struct lttng_consumer_stream *stream)
+{
+       int ret;
+       char full_path[PATH_MAX];
+       char *path_name_id = NULL;
+       char *path;
+
+       assert(stream);
+       assert(stream->net_seq_idx == (uint64_t) -1ULL);
+
+       ret = snprintf(full_path, sizeof(full_path), "%s/%s",
+                       stream->chan->pathname, stream->name);
+       if (ret < 0) {
+               PERROR("snprintf create output file");
+               goto error;
+       }
+
+       /*
+        * If we split the trace in multiple files, we have to add the tracefile
+        * current count at the end of the tracefile name
+        */
+       if (stream->chan->tracefile_size > 0) {
+               ret = asprintf(&path_name_id, "%s_%" PRIu64, full_path,
+                               stream->tracefile_count_current);
+               if (ret < 0) {
+                       PERROR("Allocating path name ID");
+                       goto error;
+               }
+               path = path_name_id;
+       } else {
+               path = full_path;
+       }
+
+       ret = run_as_open(path, O_WRONLY | O_CREAT | O_TRUNC,
+                       S_IRWXU | S_IRWXG | S_IRWXO, stream->uid, stream->gid);
+       if (ret < 0) {
+               PERROR("open stream path %s", path);
+               goto error_open;
+       }
+       stream->out_fd = ret;
+       stream->tracefile_size_current = 0;
+
+error_open:
+       free(path_name_id);
+error:
+       return ret;
+}
+
+/*
+ * Change the output tracefile according to the tracefile_size and
+ * tracefile_count parameters. The stream lock MUST be held before calling this
+ * function because we are modifying the stream status.
+ *
+ * Return 0 on success or else a negative value.
+ */
+static int rotate_output_file(struct lttng_consumer_stream *stream)
+{
+       int ret;
+
+       assert(stream);
+       assert(stream->tracefile_size_current);
+
+       ret = close(stream->out_fd);
+       if (ret < 0) {
+               PERROR("Closing tracefile");
+               goto end;
+       }
+
+       if (stream->chan->tracefile_count > 0) {
+               stream->tracefile_count_current =
+                       (stream->tracefile_count_current + 1) %
+                       stream->chan->tracefile_count;
+       } else {
+               stream->tracefile_count_current++;
+       }
+
+       return lttng_create_output_file(stream);
+
+end:
+       return ret;
+}
+
 /*
  * Mmap the ring buffer, read it and write the data to the tracefile. This is a
  * core function for writing trace buffers to either the local filesystem or
@@ -1390,6 +1481,21 @@ ssize_t lttng_consumer_on_read_subbuffer_mmap(
        } else {
                /* No streaming, we have to set the len with the full padding */
                len += padding;
+
+               /*
+                * Check if we need to change the tracefile before writing the packet.
+                */
+               if (stream->chan->tracefile_size > 0 &&
+                               (stream->tracefile_size_current + len) >
+                               stream->chan->tracefile_size) {
+                       ret = rotate_output_file(stream);
+                       if (ret < 0) {
+                               ERR("Rotating output file");
+                               goto end;
+                       }
+                       outfd = stream->out_fd;
+               }
+               stream->tracefile_size_current += len;
        }
 
        while (len > 0) {
@@ -1552,6 +1658,21 @@ ssize_t lttng_consumer_on_read_subbuffer_splice(
        } else {
                /* No streaming, we have to set the len with the full padding */
                len += padding;
+
+               /*
+                * Check if we need to change the tracefile before writing the packet.
+                */
+               if (stream->chan->tracefile_size > 0 &&
+                               (stream->tracefile_size_current + len) >
+                               stream->chan->tracefile_size) {
+                       ret = rotate_output_file(stream);
+                       if (ret < 0) {
+                               ERR("Rotating output file");
+                               goto end;
+                       }
+                       outfd = stream->out_fd;
+               }
+               stream->tracefile_size_current += len;
        }
 
        while (len > 0) {