[lttng-dev] [BABELTRACE PATCH] Parse LTTng indexes

Julien Desfossez jdesfossez at efficios.com
Thu Nov 21 11:05:20 EST 2013


If a trace file has an associated index (same filename and .idx suffix in the
"index" folder), we open it and use it instead of generating the index at open.

Signed-off-by: Julien Desfossez <jdesfossez at efficios.com>
---
 formats/ctf/ctf.c                  | 216 ++++++++++++++++++++++++++++++++++++-
 include/Makefile.am                |   1 +
 include/babeltrace/ctf/ctf-index.h |  58 ++++++++++
 include/babeltrace/ctf/types.h     |   1 +
 4 files changed, 271 insertions(+), 5 deletions(-)
 create mode 100644 include/babeltrace/ctf/ctf-index.h

diff --git a/formats/ctf/ctf.c b/formats/ctf/ctf.c
index 60d9c9f..7a0a383 100644
--- a/formats/ctf/ctf.c
+++ b/formats/ctf/ctf.c
@@ -35,6 +35,7 @@
 #include <babeltrace/context-internal.h>
 #include <babeltrace/compat/uuid.h>
 #include <babeltrace/endian.h>
+#include <babeltrace/ctf/ctf-index.h>
 #include <inttypes.h>
 #include <stdio.h>
 #include <sys/mman.h>
@@ -71,6 +72,8 @@
 
 #define NSEC_PER_SEC 1000000000ULL
 
+#define INDEX_PATH "./index/%s.idx"
+
 int opt_clock_cycles,
 	opt_clock_seconds,
 	opt_clock_date,
@@ -1666,6 +1669,153 @@ error:
 	return ret;
 }
 
+static
+int import_stream_packet_index(struct ctf_trace *td,
+		struct ctf_file_stream *file_stream)
+{
+	struct ctf_stream_declaration *stream;
+	struct ctf_stream_pos *pos;
+	struct ctf_packet_index ctf_index;
+	struct ctf_packet_index_file_hdr index_hdr;
+	uint64_t packet_map_len = DEFAULT_HEADER_LEN;
+	struct packet_index index;
+	int index_read;
+	int ret = 0;
+	int first_packet = 1;
+	size_t filesize;
+	struct stat filestats;
+	size_t len;
+
+	pos = &file_stream->pos;
+
+	len = fread(&index_hdr, sizeof(index_hdr), 1, pos->index_fp);
+	if (len != 1) {
+		perror("read index file header");
+		goto error;
+	}
+
+	/* Check the index header */
+	if (be32toh(index_hdr.magic) != CTF_INDEX_MAGIC) {
+		fprintf(stderr, "[error] wrong index magic\n");
+		ret = -1;
+		goto error;
+	}
+	if (be32toh(index_hdr.index_major) != CTF_INDEX_MAJOR ||
+			be32toh(index_hdr.index_minor) != CTF_INDEX_MINOR) {
+		fprintf(stderr, "[error] Incompatible index file %" PRIu64
+				".%" PRIu64 ", supported %d.%d\n",
+				be64toh(index_hdr.index_major),
+				be64toh(index_hdr.index_minor), CTF_INDEX_MAJOR,
+				CTF_INDEX_MINOR);
+		ret = -1;
+		goto error;
+	}
+
+	while((index_read = fread(&ctf_index, sizeof(ctf_index), 1, pos->index_fp)) == 1) {
+		uint64_t stream_id;
+		int len_index;
+
+		index.offset = be64toh(ctf_index.offset);
+		index.packet_size = be64toh(ctf_index.packet_size);
+		index.content_size = be64toh(ctf_index.content_size);
+		index.timestamp_begin = be64toh(ctf_index.timestamp_begin);
+		index.timestamp_end = be64toh(ctf_index.timestamp_end);
+		index.events_discarded = be64toh(ctf_index.events_discarded);
+		stream_id = be64toh(ctf_index.stream_id);
+
+		if (!first_packet) {
+			/* add index to packet array */
+			g_array_append_val(file_stream->pos.packet_cycles_index, index);
+			continue;
+		}
+
+		file_stream->parent.stream_id = stream_id;
+		stream = g_ptr_array_index(td->streams, stream_id);
+		if (!stream) {
+			fprintf(stderr, "[error] Stream %" PRIu64
+					" is not declared in metadata.\n",
+					stream_id);
+			ret = -EINVAL;
+			goto error;
+		}
+		file_stream->parent.stream_class = stream;
+		ret = create_stream_definitions(td, &file_stream->parent);
+		if (ret)
+			goto error;
+
+		ret = fstat(pos->fd, &filestats);
+		if (ret < 0)
+			goto error;
+
+		if (!filestats.st_size) {
+			fprintf(stderr, "[error] Empty trace file\n");
+			ret = -1;
+			goto error;
+		}
+		filesize = filestats.st_size;
+
+		if (filesize - pos->mmap_offset < (packet_map_len >> LOG2_CHAR_BIT)) {
+			packet_map_len = (filesize - pos->mmap_offset) << LOG2_CHAR_BIT;
+		}
+
+		if (pos->base_mma) {
+			/* unmap old base */
+			ret = munmap_align(pos->base_mma);
+			if (ret) {
+				fprintf(stderr, "[error] Unable to unmap old base: %s.\n",
+						strerror(errno));
+				return ret;
+			}
+			pos->base_mma = NULL;
+		}
+		/* map new base. Need mapping length from header. */
+		pos->base_mma = mmap_align(packet_map_len >> LOG2_CHAR_BIT, PROT_READ,
+				MAP_PRIVATE, pos->fd, pos->mmap_offset);
+		assert(pos->base_mma != MAP_FAILED);
+		/*
+		 * Use current mapping size as temporary content and packet
+		 * size.
+		 */
+		pos->content_size = packet_map_len;
+		pos->packet_size = packet_map_len;
+		pos->offset = 0;	/* Position of the packet header */
+
+		/* update trace_packet_header and stream_packet_context */
+		if (pos->prot != PROT_WRITE && file_stream->parent.trace_packet_header) {
+			/* Read packet header */
+			ret = generic_rw(&pos->parent, &file_stream->parent.trace_packet_header->p);
+			assert(!ret);
+		}
+		if (pos->prot != PROT_WRITE && file_stream->parent.stream_packet_context) {
+			/* Read packet context */
+			ret = generic_rw(&pos->parent, &file_stream->parent.stream_packet_context->p);
+			assert(!ret);
+		}
+		index.data_offset = pos->offset;
+
+		/* read events discarded len from header */
+		len_index = bt_struct_declaration_lookup_field_index(
+				file_stream->parent.stream_packet_context->declaration,
+				g_quark_from_static_string("events_discarded"));
+		if (len_index >= 0) {
+			struct bt_definition *field;
+
+			field = bt_struct_definition_get_field_from_index(
+					file_stream->parent.stream_packet_context,
+					len_index);
+			index.events_discarded_len = bt_get_int_len(field);
+		}
+		first_packet = 0;
+		/* add index to packet array */
+		g_array_append_val(file_stream->pos.packet_cycles_index, index);
+	}
+
+	ret = 0;
+
+error:
+	return ret;
+}
+
 /*
  * Note: many file streams can inherit from the same stream class
  * description (metadata).
@@ -1678,6 +1828,7 @@ int ctf_open_file_stream_read(struct ctf_trace *td, const char *path, int flags,
 	int ret, fd, closeret;
 	struct ctf_file_stream *file_stream;
 	struct stat statbuf;
+	char *index_name;
 
 	fd = openat(td->dirfd, path, flags);
 	if (fd < 0) {
@@ -1693,13 +1844,18 @@ int ctf_open_file_stream_read(struct ctf_trace *td, const char *path, int flags,
 		goto fstat_error;
 	}
 	if (S_ISDIR(statbuf.st_mode)) {
-		fprintf(stderr, "[warning] Skipping directory '%s' found in trace\n", path);
+		if (strncmp(path, "index", 5) != 0) {
+			fprintf(stderr, "[warning] Skipping directory '%s' "
+					"found in trace\n", path);
+		}
 		ret = 0;
 		goto fd_is_dir_ok;
 	}
 
 	file_stream = g_new0(struct ctf_file_stream, 1);
 	file_stream->pos.last_offset = LAST_OFFSET_POISON;
+	file_stream->pos.fd = -1;
+	file_stream->pos.index_fp = NULL;
 
 	strncpy(file_stream->parent.path, path, PATH_MAX);
 	file_stream->parent.path[PATH_MAX - 1] = '\0';
@@ -1722,19 +1878,61 @@ int ctf_open_file_stream_read(struct ctf_trace *td, const char *path, int flags,
 	 * For now, only a single clock per trace is supported.
 	 */
 	file_stream->parent.current_clock = td->parent.single_clock;
-	ret = create_stream_packet_index(td, file_stream);
-	if (ret) {
-		fprintf(stderr, "[error] Stream index creation error.\n");
-		goto error_index;
+
+	/*
+	 * Allocate the index name for this stream and try to open it.
+	 */
+	index_name = malloc((strlen(path) + sizeof(INDEX_PATH)) * sizeof(char));
+	if (!index_name) {
+		fprintf(stderr, "[error] Cannot allocate index filename\n");
+		goto error_def;
+	}
+	snprintf(index_name, strlen(path) + sizeof(INDEX_PATH),
+			INDEX_PATH, path);
+
+	if (faccessat(td->dirfd, index_name, O_RDONLY, flags) == 0) {
+		ret = openat(td->dirfd, index_name, flags);
+		if (ret < 0) {
+			perror("Index file openat()");
+			ret = -1;
+			goto error_free;
+		}
+		file_stream->pos.index_fp = fdopen(ret, "r");
+		ret = import_stream_packet_index(td, file_stream);
+		if (ret) {
+			ret = -1;
+			goto error_index;
+		}
+		ret = fclose(file_stream->pos.index_fp);
+		if (ret < 0) {
+			perror("close index");
+			goto error_free;
+		}
+	} else {
+		ret = create_stream_packet_index(td, file_stream);
+		if (ret) {
+			fprintf(stderr, "[error] Stream index creation error.\n");
+			goto error_index;
+		}
 	}
+	free(index_name);
+
 	/* Add stream file to stream class */
 	g_ptr_array_add(file_stream->parent.stream_class->streams,
 			&file_stream->parent);
 	return 0;
 
 error_index:
+	if (file_stream->pos.index_fp) {
+		ret = fclose(file_stream->pos.index_fp);
+		if (ret < 0) {
+			perror("close index");
+		}
+	}
 	if (file_stream->parent.trace_packet_header)
 		bt_definition_unref(&file_stream->parent.trace_packet_header->p);
+error_free:
+	free(index_name);
 error_def:
 	closeret = ctf_fini_pos(&file_stream->pos);
 	if (closeret) {
@@ -1761,6 +1959,7 @@ int ctf_open_trace_read(struct ctf_trace *td,
 	struct dirent *dirent;
 	struct dirent *diriter;
 	size_t dirent_len;
+	char *ext;
 
 	td->flags = flags;
 
@@ -1816,6 +2015,13 @@ int ctf_open_trace_read(struct ctf_trace *td,
 				|| !strcmp(diriter->d_name, "..")
 				|| !strcmp(diriter->d_name, "metadata"))
 			continue;
+
+		/* Ignore index files : *.idx */
+		ext = strrchr(diriter->d_name, '.');
+		if (ext && (!strcmp(ext, ".idx"))) {
+			continue;
+		}
+
 		ret = ctf_open_file_stream_read(td, diriter->d_name,
 					flags, packet_seek);
 		if (ret) {
diff --git a/include/Makefile.am b/include/Makefile.am
index ec927b9..d9996a7 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -38,6 +38,7 @@ noinst_HEADERS = \
 	babeltrace/ctf-text/types.h \
 	babeltrace/ctf/types.h \
 	babeltrace/ctf/callbacks-internal.h \
+	babeltrace/ctf/ctf-index.h \
 	babeltrace/ctf-writer/ref-internal.h \
 	babeltrace/ctf-writer/writer-internal.h \
 	babeltrace/ctf-writer/event-types-internal.h \
diff --git a/include/babeltrace/ctf/ctf-index.h b/include/babeltrace/ctf/ctf-index.h
new file mode 100644
index 0000000..ee7ea26
--- /dev/null
+++ b/include/babeltrace/ctf/ctf-index.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2013 - Julien Desfossez <jdesfossez at efficios.com>
+ *                      Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
+ *                      David Goulet <dgoulet at efficios.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef LTTNG_INDEX_H
+#define LTTNG_INDEX_H
+
+#include <limits.h>
+
+#define CTF_INDEX_MAGIC 0xC11D81C1
+#define CTF_INDEX_MAJOR 1
+#define CTF_INDEX_MINOR 0
+
+/*
+ * Header at the beginning of each index file.
+ * All integer fields are stored in big endian.
+ */
+struct ctf_packet_index_file_hdr {
+	uint32_t magic;
+	uint32_t index_major;
+	uint32_t index_minor;
+} __attribute__((__packed__));
+
+/*
+ * Packet index generated for each trace packet store in a trace file.
+ * All integer fields are stored in big endian.
+ */
+struct ctf_packet_index {
+	uint64_t offset;		/* offset of the packet in the file, in bytes */
+	uint64_t packet_size;		/* packet size, in bits */
+	uint64_t content_size;		/* content size, in bits */
+	uint64_t timestamp_begin;
+	uint64_t timestamp_end;
+	uint64_t events_discarded;
+	uint64_t stream_id;
+} __attribute__((__packed__));
+
+#endif /* LTTNG_INDEX_H */
diff --git a/include/babeltrace/ctf/types.h b/include/babeltrace/ctf/types.h
index 96c5083..eeb0c57 100644
--- a/include/babeltrace/ctf/types.h
+++ b/include/babeltrace/ctf/types.h
@@ -61,6 +61,7 @@ struct packet_index {
 struct ctf_stream_pos {
 	struct bt_stream_pos parent;
 	int fd;			/* backing file fd. -1 if unset. */
+	FILE *index_fp;		/* backing index file fp. NULL if unset. */
 	GArray *packet_cycles_index;	/* contains struct packet_index in cycles */
 	GArray *packet_real_index;	/* contains struct packet_index in ns */
 	int prot;		/* mmap protection */
-- 
1.8.3.2




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