From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx> The hist trigger for trace events will create a histogram that can be read in the trace event's hist file. The file is human readable ASCII format, but that makes it difficult to process in programs. The tracefs_hist_data*() functions convert the histogram ASCII format into structures that can be processed and converted into tables. This patch series creates an API to read and parse this data into machine code readable structures that can then be processed. There's a working program in the man page. I found the parsing of the hist file to be somewhat trivial where I only needed to implement flex to do most of the work and was able to avoid using bison. That said, there are still some histograms that can fail to parse. Namely, if any key has a comma (,) or a colon (:) in it. This includes exec names if there's a program name with a comma or colon. This can be fixed with a bit more clever tricks with the lexer, but I'll add those if this becomes an issue. This series is also in my personal github account here: https://github.com/rostedt/libtracefs/tree/read-hist Steven Rostedt (VMware) (9): tracefs: Add API tracefs_hist_data_parse() libtracefs: Parse comment for hist data information libtracefs: Change hist_data_key type to flags libtracefs: Add API tracefs_hist_data_read() libtracefs: Add API tracefs_list_dup() libtracefs: Add APIs tracefs_hist_data_keys/value_names() libtracefs: Add API tracefs_hist_data_keys/values() and next_bucket() libtracefs: Have tracefs_hist_bucket_key flags save the type libtracefs: Add man pages for tracefs_hist_data functions Documentation/libtracefs-hist-data-2.txt | 346 +++++++ Documentation/libtracefs-hist-data.txt | 294 ++++++ include/tracefs.h | 54 + src/Makefile | 7 + src/tracefs-hist-data.c | 1175 ++++++++++++++++++++++ src/tracefs-utils.c | 26 + 6 files changed, 1902 insertions(+) create mode 100644 Documentation/libtracefs-hist-data-2.txt create mode 100644 Documentation/libtracefs-hist-data.txt create mode 100644 src/tracefs-hist-data.c -- 2.30.2
