The use of `auto` hid that TraceableString<T>::begin(value) was a signed
char, and therefore `*iter` was -1, and -1/16 is 0.
Thus, a 0xFF byte was printed as \x0f. Forcing it to an unsigned type
makes it correctly become \xff.
This will "do the right thing" as long as no one expects something like
char a[] = {'a'};
TraceEvent("Event").detail("a", a);
to trace `{..., "a": "a"}`.
It will trace `{..., "a": ""}`
This is the first part of making `TraceEvent` cheaper. The main idea is
to defer calls to any code that formats string. These are the main
changes:
- TraceEvent::detail now takes a c-string instead of std::string for
literals. This prevents unnecessary allocations if the trace is not
going to be printed in the first place (for example for SevDebug).
Before that `detail` expected a `std::string` as key, which mean that
any string literal would be copied on each call.
- Templates Traceable and SpecialTraceMetricType. These templates can be
specialized for any type that needs to be printed. The actual
formatting will be deferred to after the `enabled` check. This
provides two benefits: (1) if a TraceEvent is disabled, we don't pay
for the formatting and (2) TraceEvent can trace types that it doesn't
know about.
- TraceEvent::enabled will be set in the constructor if the Severity is
passed. This will make sure that `TraceEvent::init` is not called.
- `TraceEvent::detail` will be inlined. So for disabled TraceEvent
calls, a call to detail will only introduce a if-branch which is much
cheaper than a function call.
Remove the use of relative paths. A header at foo/bar.h could be included by
files under foo/ with "bar.h", but would be included everywhere else as
"foo/bar.h". Adjust so that every include references such a header with the
latter form.
Signed-off-by: Robert Escriva <rescriva@dropbox.com>
This means that loops like `seed=1; while ./fdbserver -r simulation -s $seed;
do seed=$(($seed+1)); done` to find an example of an often failing test. This
also means joshua will report ExitCode errors on anything that has a SevError
in the log.
As a part of this, we also implicitly downgrade any injected errors to SevWarnAlways.
Meng Xu