perf hists: Do column alignment on the format iterator

We were doing column alignment in the format function for each cell,
returning a string padded with spaces so that when the next column is
printed the cursor is at its column alignment.

This ends up needlessly printing trailing spaces, do it at the format
iterator, that is where we know if it is needed, i.e. if there is more
columns to be printed.

This eliminates the need for triming lines when doing a dump using 'P'
in the TUI browser and also produces far saner results with things like
piping 'perf report' to 'less'.

Right now only the formatters for sym->name and the 'locked' column
(perf mem report), that are the ones that end up at the end of lines
in the default 'perf report', 'perf top' and 'perf mem report' tools,
the others will be done in a subsequent patch.

In the end the 'width' parameter for the formatters now mean, in
'printf' terms, the 'precision', where before it was the field 'width'.

Reported-by: Dave Jones <davej@codemonkey.org.uk>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/n/tip-s7iwl2gj23w92l6tibnrcqzr@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index 1c7544a8fe1a..840b6d6aa44f 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -122,11 +122,16 @@ struct hist_entry *__hists__add_entry(struct hists *hists,
 int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al,
 			 int max_stack_depth, void *arg);
 
+struct perf_hpp;
+struct perf_hpp_fmt;
+
 int64_t hist_entry__cmp(struct hist_entry *left, struct hist_entry *right);
 int64_t hist_entry__collapse(struct hist_entry *left, struct hist_entry *right);
 int hist_entry__transaction_len(void);
 int hist_entry__sort_snprintf(struct hist_entry *he, char *bf, size_t size,
 			      struct hists *hists);
+int hist_entry__snprintf_alignment(struct hist_entry *he, struct perf_hpp *hpp,
+				   struct perf_hpp_fmt *fmt, int printed);
 void hist_entry__delete(struct hist_entry *he);
 
 void perf_evsel__output_resort(struct perf_evsel *evsel, struct ui_progress *prog);