stacktrace: Implement ignore

If user want to ignore certain report, it could be filtered out.
The filtering list can be given with the file, each line is used
on filtering.

Usage with samples/factorial.c compiled samples/factorial.out:
$ ./heaptrace --ignore=ignore.txt samples/factorial.out
[heaptrace] initialized for /proc/227960/maps (factorial.out)
[heaptrace]   finalized for /proc/227960/maps (factorial.out)
=================================================================
[heaptrace] dump allocation sorted by 'size' for /proc/227960/maps (factorial.out)
[heaptrace] heap traced num of backtrace : 9
[heaptrace] heap traced allocation size  : 48 bytes
[heaptrace] allocator info (virtual)     : 135.168 KB
[heaptrace] allocator info (resident)    : 89.904 KB
[heaptrace] statm info (VSS/RSS/shared)  : 6.270 MB / 3.932 MB / 3.801 MB
=================================================================

$ cat ignore.txt
libfoo
bar
fac
baz

The original execution of samples/factorial.out is like followings
$ ./heaptrace samples/factorial.out
[heaptrace] initialized for /proc/227946/maps (factorial.out)
[heaptrace]   finalized for /proc/227946/maps (factorial.out)
=================================================================
[heaptrace] dump allocation sorted by 'size' for /proc/227946/maps (factorial.out)
=== backtrace #1 === [count/peak: 1/1] [size/peak: 10 bytes/10 bytes] [age: 325.674 us]
0 [0x7f71089b8b6f] malloc +0x1f (./libheaptrace.so +0x4b6f)
1 [0x557ebd3191c4] fac +0xe (samples/factorial.out +0x11c4)
2 [0x557ebd3191d8] fac +0x13 (samples/factorial.out +0x11d8)
3 [0x557ebd3191d8] fac +0x13 (samples/factorial.out +0x11d8)
4 [0x557ebd3191d8] fac +0x13 (samples/factorial.out +0x11d8)
5 [0x557ebd3191d8] fac +0x13 (samples/factorial.out +0x11d8)
6 [0x557ebd3191d8] fac +0x13 (samples/factorial.out +0x11d8)
7 [0x557ebd3191d8] fac +0x13 (samples/factorial.out +0x11d8)

--- snip ---

=== backtrace #9 === [count/peak: 2/2] [size/peak: 1 bytes/1 bytes] [age: 330.780 us]
0 [0x7f71089b8b6f] malloc +0x1f (./libheaptrace.so +0x4b6f)
1 [0x557ebd3191a5] fac +0x7 (samples/factorial.out +0x11a5)
2 [0x557ebd3191d8] fac +0x13 (samples/factorial.out +0x11d8)
3 [0x557ebd3191d8] fac +0x13 (samples/factorial.out +0x11d8)
4 [0x557ebd3191d8] fac +0x13 (samples/factorial.out +0x11d8)
5 [0x557ebd3191d8] fac +0x13 (samples/factorial.out +0x11d8)
6 [0x557ebd3191d8] fac +0x13 (samples/factorial.out +0x11d8)
7 [0x557ebd3191d8] fac +0x13 (samples/factorial.out +0x11d8)

[heaptrace] heap traced num of backtrace : 9
[heaptrace] heap traced allocation size  : 48 bytes
[heaptrace] allocator info (virtual)     : 135.168 KB
[heaptrace] allocator info (resident)    : 89.776 KB
[heaptrace] statm info (VSS/RSS/shared)  : 6.270 MB / 3.932 MB / 3.801 MB
=================================================================

Signed-off-by: Bojun Seo <bojun.seo.0@gmail.com>

src/stacktrace.cc

@@ -314,21 +314,18 @@ print_dump_stackmap_footer(const std::vector<std::pair<stack_trace_t, stack_info
 static void print_dump_stackmap(std::vector<std::pair<stack_trace_t, stack_info_t>> &sorted_stack)
 {
 	const time_point_t current = std::chrono::steady_clock::now();
-	int cnt = 0;
+	int cnt = 1;
+	int top = opts.top;
+	int i = 0;
 
 	size_t stack_size = sorted_stack.size();
-	for (int i = 0; i < stack_size; i++) {
+	while (i < stack_size && i < top) {
 		const stack_info_t &info = sorted_stack[i].second;
-
-		if (i >= opts.top)
-			break;
-
 		const stack_trace_t &stack_trace = sorted_stack[i].first;
 		std::string age = get_delta_time_unit(current - info.birth_time);
 		std::stringstream ss_intro;
 		std::stringstream ss_bt;
 
-		++cnt;
 		ss_intro << "=== backtrace #" << cnt << " === [count/peak: " << info.count << "/"
 			 << info.peak_count << "] "
 			 << "[size/peak: " << get_byte_unit(info.total_size) << "/"
@@ -337,22 +334,28 @@ static void print_dump_stackmap(std::vector<std::pair<stack_trace_t, stack_info_
 		for (int j = 0; j < info.stack_depth; j++)
 			get_backtrace_string(j, stack_trace[j], ss_bt);
 
-		pr_out("%s%s\n", ss_intro.str().c_str(), ss_bt.str().c_str());
+		if (is_ignored(ss_bt.str())) {
+			++top;
+		}
+		else {
+			pr_out("%s%s\n", ss_intro.str().c_str(), ss_bt.str().c_str());
+			++cnt;
+		}
+		++i;
 	}
 }
 
 static void
 print_dump_stackmap_flamegraph(std::vector<std::pair<stack_trace_t, stack_info_t>> &sorted_stack)
 {
 	size_t stack_size = sorted_stack.size();
-	for (int i = 0; i < stack_size; i++) {
+	int i = 0;
+	int top = opts.top;
+
+	while (i < stack_size && i < top) {
 		const stack_info_t &info = sorted_stack[i].second;
 		uint64_t size = info.total_size;
 		const char *semicolon = "";
-
-		if (i >= opts.top)
-			break;
-
 		const stack_trace_t &stack_trace = sorted_stack[i].first;
 		std::stringstream ss_bt;
 
@@ -361,8 +364,14 @@ print_dump_stackmap_flamegraph(std::vector<std::pair<stack_trace_t, stack_info_t
 			get_backtrace_string_flamegraph(stack_trace[j], semicolon, ss_bt);
 			semicolon = ";";
 		}
-		pr_out("%s", ss_bt.str().c_str());
-		pr_out(" %" PRIu64 "\n", size);
+		if (is_ignored(ss_bt.str())) {
+			++top;
+		}
+		else {
+			pr_out("%s", ss_bt.str().c_str());
+			pr_out(" %" PRIu64 "\n", size);
+		}
+		++i;
 	}
 
 	fflush(outfp);