----- Original Message ----- > From: "Julien Desfossez" <[email protected]> > To: "mathieu desnoyers" <[email protected]> > Cc: [email protected], "Julien Desfossez" <[email protected]> > Sent: Friday, November 29, 2013 11:43:39 PM > Subject: [BABELTRACE PATCH] Fix data_offset when importing the indexes > > When importing an index, we don't have the data_offset and we want to > mmap the tracefile only when needed, so we introduce a new function to > only compute this information when we are going to use a new packet.
Merged with tiny cleanup. Thanks! Mathieu > > Signed-off-by: Julien Desfossez <[email protected]> > --- > formats/ctf/ctf.c | 106 > +++++++++++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 105 insertions(+), 1 deletion(-) > > diff --git a/formats/ctf/ctf.c b/formats/ctf/ctf.c > index 5cf8097..b8103c5 100644 > --- a/formats/ctf/ctf.c > +++ b/formats/ctf/ctf.c > @@ -627,6 +627,103 @@ error: > return ret; > } > > +static > +int find_data_offset(struct ctf_stream_pos *pos, > + struct ctf_file_stream *file_stream, > + struct packet_index *packet_index) > +{ > + uint64_t packet_map_len = DEFAULT_HEADER_LEN, tmp_map_len; > + struct stat filestats; > + int ret; > + size_t filesize; > + > + pos = &file_stream->pos; > + > + ret = fstat(pos->fd, &filestats); > + if (ret < 0) > + return ret; > + filesize = filestats.st_size; > + > + /* Deal with empty files */ > + if (!filesize) { > + return 0; > + } > + > +begin: > + 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); > + > + 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); > + if (ret) { > + if (ret == -EFAULT) > + goto retry; > + } > + } > + 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); > + if (ret) { > + if (ret == -EFAULT) > + goto retry; > + } > + } > + packet_index->data_offset = pos->offset; > + > + /* 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; > + > + return 0; > + > + /* Retry with larger mapping */ > +retry: > + if (packet_map_len == ((filesize - pos->mmap_offset) << LOG2_CHAR_BIT)) > { > + /* > + * Reached EOF, but still expecting header/context data. > + */ > + fprintf(stderr, "[error] Reached end of file, but still > expecting header > or context fields.\n"); > + return -EFAULT; > + } > + /* Double the mapping len, and retry */ > + tmp_map_len = packet_map_len << 1; > + if (tmp_map_len >> 1 != packet_map_len) { > + /* Overflow */ > + fprintf(stderr, "[error] Packet mapping length overflow\n"); > + return -EFAULT; > + } > + packet_map_len = tmp_map_len; > + goto begin; > +} > + > + > int ctf_init_pos(struct ctf_stream_pos *pos, struct bt_trace_descriptor > *trace, > int fd, int open_flags) > { > @@ -845,11 +942,17 @@ void ctf_packet_seek(struct bt_stream_pos *stream_pos, > size_t index, int whence) > struct packet_index, > pos->cur_index); > file_stream->parent.real_timestamp = > packet_index->timestamp_begin; > - pos->mmap_offset = packet_index->offset; > > /* Lookup context/packet size in index */ > + if (packet_index->data_offset == -1) { > + ret = find_data_offset(pos, file_stream, packet_index); > + if (ret < 0) { > + return; > + } > + } > pos->content_size = packet_index->content_size; > pos->packet_size = packet_index->packet_size; > + pos->mmap_offset = packet_index->offset; > if (packet_index->data_offset < packet_index->content_size) { > pos->offset = 0; /* will read headers */ > } else if (packet_index->data_offset == > packet_index->content_size) { > @@ -1748,6 +1851,7 @@ int import_stream_packet_index(struct ctf_trace *td, > index.timestamp_end = be64toh(ctf_index.timestamp_end); > index.events_discarded = be64toh(ctf_index.events_discarded); > index.events_discarded_len = 64; > + index.data_offset = -1; > stream_id = be64toh(ctf_index.stream_id); > > if (!first_packet) { > -- > 1.8.3.2 > > -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com _______________________________________________ lttng-dev mailing list [email protected] http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
