X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Findex%2Findex.c;h=066618e8bd1a70ea3a7bb7ebe9e2b4b76ece1cc1;hp=3d22ca61cc1ad720e7e50270137053c6d5f5a787;hb=de7e372efecc2cf51921f2ac5a657337e04a39d3;hpb=309167d2a6f59d0c8cbf64eb23ba912cdea76a34

diff --git a/src/common/index/index.c b/src/common/index/index.c
index 3d22ca61c..066618e8b 100644
--- a/src/common/index/index.c
+++ b/src/common/index/index.c
@@ -16,11 +16,15 @@
  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <assert.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <fcntl.h>
 
 #include <common/common.h>
 #include <common/defaults.h>
+#include <common/compat/endian.h>
 #include <common/utils.h>
 
 #include "index.h"
@@ -34,24 +38,55 @@ int index_create_file(char *path_name, char *stream_name, int uid, int gid,
 		uint64_t size, uint64_t count)
 {
 	int ret, fd = -1;
-	struct lttng_packet_index_file_hdr hdr;
+	ssize_t size_ret;
+	struct ctf_packet_index_file_hdr hdr;
+	char fullpath[PATH_MAX];
 
-	ret = utils_create_stream_file(path_name, stream_name, size, count, uid,
+	ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR,
+			path_name);
+	if (ret < 0) {
+		PERROR("snprintf index path");
+		goto error;
+	}
+
+	/* Create index directory if necessary. */
+	ret = utils_mkdir(fullpath, S_IRWXU | S_IRWXG, uid, gid);
+	if (ret < 0) {
+		if (errno != EEXIST) {
+			PERROR("Index trace directory creation error");
+			goto error;
+		}
+	}
+
+	/*
+	 * 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.
+	 */
+	ret = utils_unlink_stream_file(fullpath, stream_name, size, count, uid,
+			gid, DEFAULT_INDEX_FILE_SUFFIX);
+	if (ret < 0 && errno != ENOENT) {
+		goto error;
+	}
+	ret = utils_create_stream_file(fullpath, stream_name, size, count, uid,
 			gid, DEFAULT_INDEX_FILE_SUFFIX);
 	if (ret < 0) {
 		goto error;
 	}
 	fd = ret;
 
-	memcpy(hdr.magic, INDEX_MAGIC, sizeof(hdr.magic));
-	hdr.index_major = htobe32(INDEX_MAJOR);
-	hdr.index_minor = htobe32(INDEX_MINOR);
+	hdr.magic = htobe32(CTF_INDEX_MAGIC);
+	hdr.index_major = htobe32(CTF_INDEX_MAJOR);
+	hdr.index_minor = htobe32(CTF_INDEX_MINOR);
+	hdr.packet_index_len = htobe32(sizeof(struct ctf_packet_index));
 
-	do {
-		ret = write(fd, &hdr, sizeof(hdr));
-	} while (ret < 0 && errno == EINTR);
-	if (ret < 0) {
+	size_ret = lttng_write(fd, &hdr, sizeof(hdr));
+	if (size_ret < sizeof(hdr)) {
 		PERROR("write index header");
+		ret = -1;
 		goto error;
 	}
 
@@ -72,21 +107,98 @@ error:
 /*
  * Write index values to the given fd of size len.
  *
- * Return 0 on success or else a negative value on error.
+ * Return "len" on success or else < len on error. errno contains error
+ * details.
  */
-int index_write(int fd, struct lttng_packet_index *index, size_t len)
+ssize_t index_write(int fd, struct ctf_packet_index *index, size_t len)
 {
-	int ret;
+	ssize_t ret;
 
-	assert(fd >= 0);
 	assert(index);
 
-	do {
-		ret = write(fd, index, len);
-	} while (ret < 0 && errno == EINTR);
-	if (ret < 0) {
+	if (fd < 0) {
+		ret = -EINVAL;
+		goto error;
+	}
+
+	ret = lttng_write(fd, index, len);
+	if (ret < len) {
 		PERROR("writing index file");
 	}
 
+error:
+	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;
 }