Add support for SystemTap profile script output, add process name prefix

cmd/stackcollapse-stap

@@ -0,0 +1,20 @@
+#!/usr/bin/env node
+
+/*
+ * cmd/stackcollapse: emit collapsed stack traces from stap output
+ */
+
+var mod_bunyan = require('bunyan');
+var mod_stackvis = require('../lib/stackvis');
+
+var log = new mod_bunyan({
+    'name': 'stackcollapse',
+    'stream': process.stderr
+});
+
+var reader = mod_stackvis.readerLookup('stap');
+var writer = mod_stackvis.writerLookup('collapsed');
+
+mod_stackvis.pipeStacks(log, process.stdin, reader, writer, process.stdout,
+    function () {});
+process.stdin.resume();

lib/input-perf.js

@@ -25,6 +25,7 @@ function PerfStreamReader(input, log)
 {
 	this.dsr_log = log;
 	this.dsr_linenum = 0;
+	this.dsr_prefix = '';
 	this.dsr_stack = [];
 	this.dsr_carrier = mod_carrier.carry(input);
 	this.dsr_carrier.on('line', this.onLine.bind(this));
@@ -43,9 +44,12 @@ PerfStreamReader.prototype.onLine = function (line)
 	if (/^#/.exec(line))
 		return;
 
-	/* Skip summary lines */
-	if (/^\S+/.exec(line))
+	/* Get process name from summary line, to use as prefix */
+	var match = /(^\w+)\s+/.exec(line);
+	if (match) {
+		this.dsr_prefix = match[1];
 		return;
+	}
 
 	/*
 	 * In general, lines may have leading or trailing whitespace and the
@@ -68,6 +72,7 @@ PerfStreamReader.prototype.onLine = function (line)
 		}
 
 		this.emit('stack', this.dsr_stack, 1);
+		this.dsr_prefix = '';
 		this.dsr_stack = [];
 		return;
 	}
@@ -90,6 +95,11 @@ PerfStreamReader.prototype.onLine = function (line)
 		return;
 	}
 
+	/* Add prefix */
+	if (this.dsr_prefix.length > 0) {
+		frame = this.dsr_prefix + '`' + frame;
+	}
+
 	this.dsr_stack.unshift(frame);
 };
 

lib/input-stap.js

@@ -0,0 +1,145 @@
+/*
+ * lib/input-stap.js: reads output from a stap profiling script, which emits
+ * stanzas that look like this:
+ *
+ * ubt["bar+0x32 [foo]
+ * foo+0x57 [foo]
+ * main+0x48 [foo]
+ * __libc_start_main+0xed [libc-2.15.so]
+ * _start+0x29 [foo]"]=0x77
+ *
+ * You can generate such output with:
+ *
+ *   # stap \
+ *       -e "global ubt; \
+ *           probe timer.profile { ubt[sprint_ubacktrace()] += 1 }; \
+ *           probe timer.s(30) { exit() }" \
+ *       -o stap.out
+ *
+ * If stap warns about missing unwind data for a module, and stap
+ * suggests adding '-d /lib/libquux.so', which you know to be a shared
+ * library used by the 'foo' binary, add the following to the above
+ * command:
+ *
+ *       -d /path/to/foo $(ldd /path/to/foo | awk 'NF==4 { print "-d", $3 }')
+ *
+ * to deal with all warnings related to shared libraries used by 'foo',
+ * all at once.
+ */
+
+var mod_util = require('util');
+var mod_events = require('events');
+
+var mod_carrier = require('carrier');
+
+exports.reader = PerfStreamReader;
+
+function PerfStreamReader(input, log)
+{
+	this.dsr_log = log;
+	this.dsr_linenum = 0;
+	this.dsr_addingframes = false;
+	this.dsr_prefixes = [];
+	this.dsr_stack = [];
+	this.dsr_carrier = mod_carrier.carry(input);
+	this.dsr_carrier.on('line', this.onLine.bind(this));
+	this.dsr_carrier.on('end', this.onEnd.bind(this));
+
+	mod_events.EventEmitter.call(this);
+}
+
+mod_util.inherits(PerfStreamReader, mod_events.EventEmitter);
+
+PerfStreamReader.prototype.onLine = function (line)
+{
+	++this.dsr_linenum;
+
+	var match;
+	if (!this.dsr_addingframes) {
+		/* Skip array name */
+		line.replace(/^\w+\[/, '');
+
+		/* Find and add prefixes */
+		while (true) {
+			/* JSSTYLED */
+			match = /(?:"([^"]*)",)(.*$)/.exec(line);
+			if (!match)
+				break;
+			this.dsr_prefixes.push(match[1]);
+			line = match[2];
+		}
+
+		/* Find first frame */
+		/* JSSTYLED */
+		match = /(?:"(.*$))/.exec(line);
+		if (!match) {
+			this.dsr_log.warn('line ' + this.dsr_linenum +
+			    ': no first frame found');
+			return;
+		}
+		line = match[1];
+		this.dsr_addingframes = true;
+	}
+
+	/* Look for count */
+	var count;
+	/* JSSTYLED */
+	match = /(^.*)"\]=(\w+$)/.exec(line);
+	if (match) {
+		line = match[1];
+		count = parseInt(match[2], 16);
+		this.dsr_addingframes = false;
+	}
+
+	/*
+	 * In general, frames have one of the following sets of components:
+	 *
+	 *	address
+	 *	address [module+offset]
+	 *	function+offset [module]
+	 *
+	 * We try to avoid assuming too much about the form in order to support
+	 * various annotations provided by ustack helpers.
+	 */
+	var frame = line;
+	frame = frame.replace(/ \[(\S+)\]$/, '');
+	/* JSSTYLED */
+	frame = frame.replace(/\+.*/, '');
+
+	/*
+	 * Remove both function and template parameters from demangled C++
+	 * frames, but skip the first two characters because they're used by the
+	 * Node.js ustack helper as separators.
+	 */
+	/* JSSTYLED */
+	frame = frame.replace(/(..)[(<].*/, '$1');
+
+	if (line.length === 0) {
+		if (this.dsr_stack.length !== 0)
+			this.dsr_log.warn('line ' + this.dsr_linenum +
+			    ': unexpected blank line');
+		return;
+	}
+
+	/* Add prefixes */
+	if (this.dsr_prefixes.length > 0) {
+		frame = this.dsr_prefixes.join('`') + '`' + frame;
+	}
+
+	this.dsr_stack.unshift(frame);
+
+	if (!this.dsr_addingframes) {
+		this.emit('stack', this.dsr_stack, count);
+		this.dsr_prefixes = [];
+		this.dsr_stack = [];
+	}
+};
+
+PerfStreamReader.prototype.onEnd = function ()
+{
+	if (this.dsr_stack.length !== 0)
+		this.dsr_log.warn('line ' + this.dsr_linenum +
+		    ': unexpected end of stream');
+
+	this.emit('end');
+};

package.json

@@ -6,6 +6,8 @@
 	"bin": {
 		"flamegraph": "./cmd/flamegraph",
 		"stackcollapse": "./cmd/stackcollapse",
+		"stackcollapse-perf": "./cmd/stackcollapse-perf",
+		"stackcollapse-stap": "./cmd/stackcollapse-stap",
 		"stackvis": "./cmd/stackvis"
 	},