/*
   * builtin-diff.c
   *
   * Builtin diff command: Analyze two perf.data input files, look up and read
   * DSOs and symbol information, sort them and produce a diff.
   */
  #include "builtin.h"
  
  #include "util/debug.h"
  #include "util/event.h"
  #include "util/hist.h"

  #include "util/evsel.h"

  #include "util/session.h"

  #include "util/tool.h"

  #include "util/sort.h"
  #include "util/symbol.h"
  #include "util/util.h"
  
  #include <stdlib.h>

  static char const *input_old = "perf.data.old",
  		  *input_new = "perf.data";

  static char	  diff__default_sort_order[] = "dso,symbol";

  static bool  force;

  static bool show_displacement;

  static int hists__add_entry(struct hists *self,

  			    struct addr_location *al, u64 period)

  {

  	if (__hists__add_entry(self, al, NULL, period) != NULL)

  		return 0;
  	return -ENOMEM;

  }

  static int diff__process_sample_event(struct perf_tool *tool __used,

  				      union perf_event *event,

  				      struct perf_sample *sample,

  				      struct perf_evsel *evsel __used,

  				      struct machine *machine)

  {
  	struct addr_location al;

  	if (perf_event__preprocess_sample(event, machine, &al, sample, NULL) < 0) {

  		pr_warning("problem processing %d event, skipping it.
  ",
  			   event->header.type);
  		return -1;
  	}

  	if (al.filtered || al.sym == NULL)

  		return 0;

  	if (hists__add_entry(&evsel->hists, &al, sample->period)) {

  		pr_warning("problem incrementing symbol period, skipping event
  ");

  		return -1;
  	}

  	evsel->hists.stats.total_period += sample->period;

  	return 0;
  }

  static struct perf_tool perf_diff = {

  	.sample	= diff__process_sample_event,

  	.mmap	= perf_event__process_mmap,
  	.comm	= perf_event__process_comm,
  	.exit	= perf_event__process_task,
  	.fork	= perf_event__process_task,
  	.lost	= perf_event__process_lost,

  	.ordered_samples = true,
  	.ordering_requires_timestamps = true,

  };
  
  static void perf_session__insert_hist_entry_by_name(struct rb_root *root,
  						    struct hist_entry *he)
  {
  	struct rb_node **p = &root->rb_node;
  	struct rb_node *parent = NULL;
  	struct hist_entry *iter;
  
  	while (*p != NULL) {

  		parent = *p;
  		iter = rb_entry(parent, struct hist_entry, rb_node);

  		if (hist_entry__cmp(he, iter) < 0)

  			p = &(*p)->rb_left;

  		else

  			p = &(*p)->rb_right;

  	}
  
  	rb_link_node(&he->rb_node, parent, p);
  	rb_insert_color(&he->rb_node, root);
  }

  static void hists__resort_entries(struct hists *self)

  {
  	unsigned long position = 1;
  	struct rb_root tmp = RB_ROOT;

  	struct rb_node *next = rb_first(&self->entries);

  
  	while (next != NULL) {
  		struct hist_entry *n = rb_entry(next, struct hist_entry, rb_node);
  
  		next = rb_next(&n->rb_node);

  		rb_erase(&n->rb_node, &self->entries);

  		n->position = position++;
  		perf_session__insert_hist_entry_by_name(&tmp, n);
  	}

  	self->entries = tmp;

  }

  static void hists__set_positions(struct hists *self)

  {

  	hists__output_resort(self);
  	hists__resort_entries(self);

  }

  static struct hist_entry *hists__find_entry(struct hists *self,
  					    struct hist_entry *he)

  {

  	struct rb_node *n = self->entries.rb_node;

  
  	while (n) {
  		struct hist_entry *iter = rb_entry(n, struct hist_entry, rb_node);

  		int64_t cmp = hist_entry__cmp(he, iter);

  		if (cmp < 0)

  			n = n->rb_left;

  		else if (cmp > 0)

  			n = n->rb_right;

  		else 
  			return iter;

  	}
  
  	return NULL;
  }

  static void hists__match(struct hists *older, struct hists *newer)

  {
  	struct rb_node *nd;

  	for (nd = rb_first(&newer->entries); nd; nd = rb_next(nd)) {

  		struct hist_entry *pos = rb_entry(nd, struct hist_entry, rb_node);

  		pos->pair = hists__find_entry(older, pos);

  	}
  }

  static int __cmd_diff(void)
  {
  	int ret, i;
  	struct perf_session *session[2];

  	session[0] = perf_session__new(input_old, O_RDONLY, force, false, &perf_diff);
  	session[1] = perf_session__new(input_new, O_RDONLY, force, false, &perf_diff);

  	if (session[0] == NULL || session[1] == NULL)
  		return -ENOMEM;
  
  	for (i = 0; i < 2; ++i) {

  		ret = perf_session__process_events(session[i], &perf_diff);

  		if (ret)
  			goto out_delete;

  	}

  	hists__output_resort(&session[1]->hists);

  	if (show_displacement)

  		hists__set_positions(&session[0]->hists);

  	hists__match(&session[0]->hists, &session[1]->hists);
  	hists__fprintf(&session[1]->hists, &session[0]->hists,

  		       show_displacement, true, 0, 0, stdout);

  out_delete:
  	for (i = 0; i < 2; ++i)
  		perf_session__delete(session[i]);
  	return ret;
  }

  static const char * const diff_usage[] = {

  	"perf diff [<options>] [old_file] [new_file]",

  	NULL,

  };
  
  static const struct option options[] = {

  	OPT_INCR('v', "verbose", &verbose,

  		    "be more verbose (show symbol address, etc)"),

  	OPT_BOOLEAN('M', "displacement", &show_displacement,

  		    "Show position displacement relative to baseline"),

  	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
  		    "dump raw trace in ASCII"),
  	OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
  	OPT_BOOLEAN('m', "modules", &symbol_conf.use_modules,
  		    "load module symbols - WARNING: use only with -k and LIVE kernel"),

  	OPT_STRING('d', "dsos", &symbol_conf.dso_list_str, "dso[,dso...]",
  		   "only consider symbols in these dsos"),
  	OPT_STRING('C', "comms", &symbol_conf.comm_list_str, "comm[,comm...]",
  		   "only consider symbols in these comms"),
  	OPT_STRING('S', "symbols", &symbol_conf.sym_list_str, "symbol[,symbol...]",
  		   "only consider these symbols"),

  	OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
  		   "sort by key(s): pid, comm, dso, symbol, parent"),
  	OPT_STRING('t', "field-separator", &symbol_conf.field_sep, "separator",
  		   "separator for columns, no spaces will be added between "
  		   "columns '.' is reserved."),

  	OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
  		    "Look for files with symbols relative to this directory"),

  	OPT_END()
  };
  
  int cmd_diff(int argc, const char **argv, const char *prefix __used)
  {

  	sort_order = diff__default_sort_order;

  	argc = parse_options(argc, argv, options, diff_usage, 0);
  	if (argc) {
  		if (argc > 2)
  			usage_with_options(diff_usage, options);
  		if (argc == 2) {
  			input_old = argv[0];
  			input_new = argv[1];
  		} else
  			input_new = argv[0];

  	} else if (symbol_conf.default_guest_vmlinux_name ||
  		   symbol_conf.default_guest_kallsyms) {
  		input_old = "perf.data.host";
  		input_new = "perf.data.guest";

  	}

  	symbol_conf.exclude_other = false;

  	if (symbol__init() < 0)
  		return -1;
  
  	setup_sorting(diff_usage, options);

  	setup_pager();

  
  	sort_entry__setup_elide(&sort_dso, symbol_conf.dso_list, "dso", NULL);
  	sort_entry__setup_elide(&sort_comm, symbol_conf.comm_list, "comm", NULL);
  	sort_entry__setup_elide(&sort_sym, symbol_conf.sym_list, "symbol", NULL);

  	return __cmd_diff();
  }