Applications like firefox have a very conservative approach and mark
surfaces dirty before every render. As we record the image data every
time, firefox traces can grow very large with redundant data - so allow
the user to disable mark dirty tracing.
In order to have locale-independent output of decimal values, we need to
manually transform such numbers into strings. As this is a solved problem
for cairo, we adopt _cairo_output_stream_printf() and in particular the
_cairo_dtostr() routine for our own printf processing.
This interferes with the application being traced. It is not clear from
printf(3) whether "%.f" is locale dependent or not - but until we have a
failure do not break applications unnecessarily!
Handle the case of tracing an application that spawns it own graphical
children but using the autonaming facility within cairo-trace. Currently
the traced process tree would all attempt to write to the same file,
creating a broken trace. This means sacrificing the display of the output
name, but allows use for a wider range of applications.
Reparsing the dwarf info for every lookup is very slow, so cache the
symbol lookups. This initial implementation is unbounded in the simple
belief that the actual number of unique lookups during a program's
lifetime should be fairly small. (Extending to a bounded MRU list is left
as an exercise for the reader.)
A limitation of the current API was that the destroy notifier was called
on the mime-data block. This prevents the user from passing in a pointer
to a managed block, for example a mime-data block belonging to a
ref-counted object. We can overcome this by allowing the user to specify
the closure to be used with the destroy notifier.
set_font_face was not consuming it's operand but blithely placing an
undefined font_face onto the operand stack, whereas set_source was
performing invalid exchanges on the stack.
Install the auxiliary library into the cairo subdirectory within the
lib path, so that it doesn't clutter $(libdir) and sets a precedent for
future auxiliary libraries.
Use the surface user-data array allow to store an arbitrary set of
alternate image representations keyed by an interned string (which
ensures that it has a unique key in the user-visible namespace).
Update the API to mirror that of cairo_surface_set_user_data() [i.e.
return a status indicator] and switch internal users of the mime-data to
the public functions.
Include a COPYING inside perf/, test/, util/ to clarify the licensing
conditions beneath the respective directories. This is because cairo
itself (libcairo.so) is LGPL-2.1/MPL-1.1 but that only relates to src/.
The auxiliary source files are under a mix of free licenses and we wish to
be clear just what license applies to each file.
In particular, cairo-trace needs to include the GPL terms and conditions.
This tool can be used to trace all the cairo function calls made by an
applications. This is useful for either extracting a test case triggering
a bug from an application, or simply to get a general idea of how an
application is using cairo.
After make install, cairo-trace program arguments, will print out all the
cairo calls to the terminal and also capture theme in ./program.$pid.trace
The format of the output is CairoScript, watch this space for more
cairo-script tools!