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#include "propagation.h"
#include <algorithm>
#include <cctype>
#include <functional>
#include <iostream>
#include <sstream>
#include "base64.h"
#include "utility.h"
namespace opentracing {
BEGIN_OPENTRACING_ABI_NAMESPACE
namespace mocktracer {
static void WriteString(std::ostream& ostream, const std::string& s) {
const uint32_t size = static_cast<uint32_t>(s.size());
ostream.write(reinterpret_cast<const char*>(&size), sizeof(size));
ostream.write(s.data(), size);
}
static void ReadString(std::istream& istream, std::string& s) {
uint32_t size = 0;
istream.read(reinterpret_cast<char*>(&size), sizeof(size));
s.resize(size);
istream.read(&s[0], size);
}
expected<void> InjectSpanContext(
const PropagationOptions& /*propagation_options*/, std::ostream& carrier,
const SpanContextData& span_context_data) {
auto trace_id = SwapEndianIfBig(span_context_data.trace_id);
carrier.write(reinterpret_cast<const char*>(&trace_id), sizeof(trace_id));
auto span_id = SwapEndianIfBig(span_context_data.span_id);
carrier.write(reinterpret_cast<const char*>(&span_id), sizeof(span_id));
const uint32_t num_baggage =
SwapEndianIfBig(static_cast<uint32_t>(span_context_data.baggage.size()));
carrier.write(reinterpret_cast<const char*>(&num_baggage),
sizeof(num_baggage));
for (auto& baggage_item : span_context_data.baggage) {
WriteString(carrier, baggage_item.first);
WriteString(carrier, baggage_item.second);
}
// Flush so that when we call carrier.good(), we'll get an accurate view of
// the error state.
carrier.flush();
if (!carrier.good()) {
return opentracing::make_unexpected(
std::make_error_code(std::errc::io_error));
}
return {};
}
expected<bool> ExtractSpanContext(
const PropagationOptions& /*propagation_options*/, std::istream& carrier,
SpanContextData& span_context_data) try {
// istream::peek returns EOF if it's in an error state, so check for an error
// state first before checking for an empty stream.
if (!carrier.good()) {
return opentracing::make_unexpected(
std::make_error_code(std::errc::io_error));
}
// Check for the case when no span is encoded.
if (carrier.peek() == EOF) {
return false;
}
carrier.read(reinterpret_cast<char*>(&span_context_data.trace_id),
sizeof(span_context_data.trace_id));
span_context_data.trace_id = SwapEndianIfBig(span_context_data.trace_id);
carrier.read(reinterpret_cast<char*>(&span_context_data.span_id),
sizeof(span_context_data.span_id));
span_context_data.span_id = SwapEndianIfBig(span_context_data.span_id);
uint32_t num_baggage = 0;
carrier.read(reinterpret_cast<char*>(&num_baggage), sizeof(num_baggage));
num_baggage = SwapEndianIfBig(num_baggage);
std::string baggage_key, baggage_value;
for (int i = 0; i < static_cast<int>(num_baggage); ++i) {
ReadString(carrier, baggage_key);
ReadString(carrier, baggage_value);
span_context_data.baggage[baggage_key] = baggage_value;
if (!carrier.good()) {
return opentracing::make_unexpected(
std::make_error_code(std::errc::io_error));
}
}
return true;
} catch (const std::bad_alloc&) {
return opentracing::make_unexpected(
std::make_error_code(std::errc::not_enough_memory));
}
expected<void> InjectSpanContext(const PropagationOptions& propagation_options,
const TextMapWriter& carrier,
const SpanContextData& span_context_data) {
std::ostringstream ostream;
auto result =
InjectSpanContext(propagation_options, ostream, span_context_data);
if (!result) {
return result;
}
std::string context_value;
try {
auto binary_encoding = ostream.str();
context_value =
Base64::encode(binary_encoding.data(), binary_encoding.size());
} catch (const std::bad_alloc&) {
return opentracing::make_unexpected(
std::make_error_code(std::errc::not_enough_memory));
}
result = carrier.Set(propagation_options.propagation_key, context_value);
if (!result) {
return result;
}
return {};
}
template <class KeyCompare>
static opentracing::expected<opentracing::string_view> LookupKey(
const opentracing::TextMapReader& carrier, opentracing::string_view key,
KeyCompare key_compare) {
// First try carrier.LookupKey since that can potentially be the fastest
// approach.
auto result = carrier.LookupKey(key);
if (result ||
!are_errors_equal(result.error(),
opentracing::lookup_key_not_supported_error)) {
return result;
}
// Fall back to iterating through all of the keys.
result = opentracing::make_unexpected(opentracing::key_not_found_error);
auto was_successful = carrier.ForeachKey(
[&](opentracing::string_view carrier_key,
opentracing::string_view value) -> opentracing::expected<void> {
if (!key_compare(carrier_key, key)) {
return {};
}
result = value;
// Found key, so bail out of the loop with a success error code.
return opentracing::make_unexpected(std::error_code{});
});
if (!was_successful && was_successful.error() != std::error_code{}) {
return opentracing::make_unexpected(was_successful.error());
}
return result;
}
template <class KeyCompare>
static opentracing::expected<bool> ExtractSpanContext(
const PropagationOptions& propagation_options,
const opentracing::TextMapReader& carrier,
SpanContextData& span_context_data, KeyCompare key_compare) {
auto value_maybe =
LookupKey(carrier, propagation_options.propagation_key, key_compare);
if (!value_maybe) {
if (are_errors_equal(value_maybe.error(),
opentracing::key_not_found_error)) {
return false;
} else {
return opentracing::make_unexpected(value_maybe.error());
}
}
auto value = *value_maybe;
std::string base64_decoding;
try {
base64_decoding = Base64::decode(value.data(), value.size());
} catch (const std::bad_alloc&) {
return opentracing::make_unexpected(
std::make_error_code(std::errc::not_enough_memory));
}
if (base64_decoding.empty()) {
return opentracing::make_unexpected(
opentracing::span_context_corrupted_error);
}
std::istringstream istream{base64_decoding};
return ExtractSpanContext(propagation_options, istream, span_context_data);
}
expected<bool> ExtractSpanContext(const PropagationOptions& propagation_options,
const TextMapReader& carrier,
SpanContextData& span_context_data) {
return ExtractSpanContext(propagation_options, carrier, span_context_data,
std::equal_to<string_view>{});
}
expected<void> InjectSpanContext(const PropagationOptions& propagation_options,
const HTTPHeadersWriter& carrier,
const SpanContextData& span_context_data) {
return InjectSpanContext(propagation_options,
static_cast<const TextMapWriter&>(carrier),
span_context_data);
}
expected<bool> ExtractSpanContext(const PropagationOptions& propagation_options,
const HTTPHeadersReader& carrier,
SpanContextData& span_context_data) {
auto iequals = [](opentracing::string_view lhs,
opentracing::string_view rhs) {
return lhs.length() == rhs.length() &&
std::equal(std::begin(lhs), std::end(lhs), std::begin(rhs),
[](char a, char b) {
return std::tolower(a) == std::tolower(b);
});
};
return ExtractSpanContext(propagation_options, carrier, span_context_data,
iequals);
}
} // namespace mocktracer
END_OPENTRACING_ABI_NAMESPACE
} // namespace opentracing
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