Create stream files relative to a stream's current trace chunk

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

diff --git a/src/common/index/index.c b/src/common/index/index.c
index 0935d702dccea0b2fd60ea4de2baa3babd9848f3..694e3d18698dd3dfe142bc9e199026a9a8f6c9b4 100644 (file)
--- a/src/common/index/index.c
+++ b/src/common/index/index.c
@@ -23,6 +23,7 @@
 #include <sys/types.h>
 #include <fcntl.h>
 
+#include <lttng/constant.h>
 #include <common/common.h>
 #include <common/defaults.h>
 #include <common/compat/endian.h>
@@ -115,6 +116,93 @@ error:
        return NULL;
 }
 
+struct lttng_index_file *lttng_index_file_create_from_trace_chunk(
+               struct lttng_trace_chunk *chunk,
+               const char *channel_path, char *stream_name,
+               uint64_t stream_file_size, uint64_t stream_count,
+               uint32_t index_major, uint32_t index_minor,
+               bool unlink_existing_file)
+{
+       struct lttng_index_file *index_file;
+       enum lttng_trace_chunk_status chunk_status;
+       int ret, fd = -1;
+       ssize_t size_ret;
+       struct ctf_packet_index_file_hdr hdr;
+       char index_directory_path[LTTNG_PATH_MAX];
+       char index_file_path[LTTNG_PATH_MAX];
+       const uint32_t element_len = ctf_packet_index_len(index_major,
+                       index_minor);
+       const int flags = O_WRONLY | O_CREAT | O_TRUNC;
+       const mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
+
+       index_file = zmalloc(sizeof(*index_file));
+       if (!index_file) {
+               PERROR("Failed to allocate lttng_index_file");
+               goto error;
+       }
+
+       ret = snprintf(index_directory_path, sizeof(index_directory_path),
+                       "%s/" DEFAULT_INDEX_DIR, channel_path);
+       if (ret < 0 || ret >= sizeof(index_directory_path)) {
+               ERR("Failed to format index directory path");
+               goto error;
+       }
+
+       ret = utils_stream_file_path(index_directory_path, stream_name,
+                       stream_file_size, stream_count,
+                       DEFAULT_INDEX_FILE_SUFFIX,
+                       index_file_path, sizeof(index_file_path));
+       if (ret) {
+               goto error;
+       }
+
+       if (unlink_existing_file) {
+               /*
+                * For tracefile rotation. We need to unlink the old
+                * file if present to synchronize with the tail of the
+                * live viewer which could be working on this same file.
+                * By doing so, any reference to the old index file
+                * stays valid even if we re-create a new file with the
+                * same name afterwards.
+                */
+               chunk_status = lttng_trace_chunk_unlink_file(chunk,
+                               index_file_path);
+               if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
+                       goto error;
+               }
+        }
+
+       chunk_status = lttng_trace_chunk_open_file(chunk, index_file_path,
+                       flags, mode, &fd);
+       if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
+               goto error;
+       }
+
+       ctf_packet_index_file_hdr_init(&hdr, index_major, index_minor);
+       size_ret = lttng_write(fd, &hdr, sizeof(hdr));
+       if (size_ret < sizeof(hdr)) {
+               PERROR("Failed to write index header");
+               goto error;
+       }
+       index_file->fd = fd;
+       index_file->major = index_major;
+       index_file->minor = index_minor;
+       index_file->element_len = element_len;
+       urcu_ref_init(&index_file->ref);
+
+       return index_file;
+
+error:
+       if (fd >= 0) {
+               ret = close(fd);
+               if (ret < 0) {
+                       PERROR("Failed to close file descriptor of index file");
+               }
+       }
+       free(index_file);
+       return NULL;
+}
+
 /*
  * Write index values to the given index file.
  *