Fix: code refactoring of viewer streams in relayd

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

diff --git a/src/common/index/index.c b/src/common/index/index.c
index 2946f7bab3335e5456d9628d9e0a3c6707e0eca6..54689677ee4a2f3dd3c56a6f06236115f659ead6 100644 (file)
--- a/src/common/index/index.c
+++ b/src/common/index/index.c
@@ -19,6 +19,8 @@
 #define _GNU_SOURCE
 #include <assert.h>
 #include <sys/stat.h>
+#include <sys/types.h>
+#include <fcntl.h>
 
 #include <common/common.h>
 #include <common/defaults.h>
@@ -108,3 +110,76 @@ ssize_t index_write(int fd, struct ctf_packet_index *index, size_t len)
 
        return ret;
 }
+
+/*
+ * Open index file using a given path, channel name and tracefile count.
+ *
+ * Return read only FD on success or else a negative value.
+ */
+int index_open(const char *path_name, const char *channel_name,
+               uint64_t tracefile_count, uint64_t tracefile_count_current)
+{
+       int ret, read_fd;
+       ssize_t read_len;
+       char fullpath[PATH_MAX];
+       struct ctf_packet_index_file_hdr hdr;
+
+       assert(path_name);
+       assert(channel_name);
+
+       if (tracefile_count > 0) {
+               ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR "/%s_%"
+                               PRIu64 DEFAULT_INDEX_FILE_SUFFIX, path_name,
+                               channel_name, tracefile_count_current);
+       } else {
+               ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR "/%s"
+                               DEFAULT_INDEX_FILE_SUFFIX, path_name, channel_name);
+       }
+       if (ret < 0) {
+               PERROR("snprintf index path");
+               goto error;
+       }
+
+       DBG("Index opening file %s in read only", fullpath);
+       read_fd = open(fullpath, O_RDONLY);
+       if (read_fd < 0) {
+               if (errno == ENOENT) {
+                       ret = -ENOENT;
+               } else {
+                       PERROR("opening index in read-only");
+               }
+               goto error;
+       }
+
+       read_len = lttng_read(read_fd, &hdr, sizeof(hdr));
+       if (read_len < 0) {
+               PERROR("Reading index header");
+               goto error_close;
+       }
+
+       if (be32toh(hdr.magic) != CTF_INDEX_MAGIC) {
+               ERR("Invalid header magic");
+               goto error_close;
+       }
+       if (be32toh(hdr.index_major) != CTF_INDEX_MAJOR ||
+                       be32toh(hdr.index_minor) != CTF_INDEX_MINOR) {
+               ERR("Invalid header version");
+               goto error_close;
+       }
+
+       return read_fd;
+
+error_close:
+       if (read_fd >= 0) {
+               int close_ret;
+
+               close_ret = close(read_fd);
+               if (close_ret < 0) {
+                       PERROR("close read fd %d", read_fd);
+               }
+       }
+       ret = -1;
+
+error:
+       return ret;
+}