ptrace utility
Purpose
DMD's builtin profiler is a very useful tool to determine the performance of individual functions and their interactions (by means of a call graph). The output it generates however - in the form of a trace.log file - can be hard to read, mainly because it writes mangled symbols. ptrace can parse and demangle this output, and convert it to a friendlier html format. The conversion to html is done via the ddoc system.
Usage
ptrace can be used in two ways:
1. Generate html 'directly' from a trace.log file. The ddoc macro's are hardcoded in ptrace.
2. Generate a .d file, and then 'compile' this with the trace.ddoc macro definition file.
ad 1) Executing ptrace without arguments will result in ptrace looking for a trace.log file in the current directly to generate html from it. If you want to specify a different file as source, or a different filename as the target, use the '-x' option to let ptrace call dmd and skip the intermediate step of compiling a D file.
ad 2) The '-t=<file>' option can be used to name the target D file. trace.ddoc contains the macros definitions used for the ddoc system, via this route it's possible to customize the output a bit. The html generated currently doesn't look that pretty in some browsers.
Example
Some entries in a trace.log file:
193 43885 32456 168 _D6ptrace5Words7opApplyMFDFKAaZiZi 2536 11271 8590 3 _D5tango4text4Util11__T4trimTaZ4trimFAaZAa
Generated html:
| Num calls | Tree Time | Func Time | Per Call | identifier | type |
|---|---|---|---|---|---|
| 193 | 43885 | 32456 | 168 | ptrace.Words.opApply | int function(int delegate(inout char[], void*), void*) |
| 2536 | 11271 | 8590 | 3 | tango.text.Util.trim!(char).trim | char[] function(char[]) |
Call graph example. Here, lodepng.Encode._encode calls lodepng.Encode.writeChunk which calls lodepng.Encode.concatUint:
| Functions that call measured function (fan in) | Num calls | |||
| Measured function symbol | Tree Time | Func Time | Num Calls | |
| Functions called by measured function (fan out) | Num calls | |||
| ubyte[] lodepng.Encode._encode(ubyte[], struct lodepng.Encode.Settings, inout ubyte[], inout struct lodepng.Common.Chunk[]) | 4 | |||
| void lodepng.Encode.writeChunk(inout ubyte[], inout struct lodepng.Common.Chunk) | 3.47e+06 | 3.46e+06 | 4 | |
| void lodepng.Encode.concatUint(inout ubyte[], uint) | 8 | |||
sourcefiles
ptrace needs tango