Use rtc::StringBuilder in stats/
This removes the dependency on sstream which will reduce binary size.
Bug: webrtc:8982
Change-Id: I153390f2d8baf3e15875c39d1f5027b3575bca31
Reviewed-on: https://webrtc-review.googlesource.com/c/115748
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Commit-Queue: Steve Anton <steveanton@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26127}diff --git a/stats/rtcstats.cc b/stats/rtcstats.cc
index a274660..d5ea319 100644
--- a/stats/rtcstats.cc
+++ b/stats/rtcstats.cc
@@ -10,10 +10,11 @@
#include "api/stats/rtcstats.h"
-#include <iomanip>
-#include <sstream>
+#include <cstdio>
+#include "rtc_base/arraysize.h"
#include "rtc_base/stringencode.h"
+#include "rtc_base/strings/string_builder.h"
namespace webrtc {
@@ -23,53 +24,54 @@
// types.
template <typename T>
std::string VectorToString(const std::vector<T>& vector) {
- if (vector.empty())
- return "[]";
- std::ostringstream oss;
- oss << "[" << rtc::ToString(vector[0]);
- for (size_t i = 1; i < vector.size(); ++i) {
- oss << "," << rtc::ToString(vector[i]);
+ rtc::StringBuilder sb;
+ sb << "[";
+ const char* separator = "";
+ for (const T& element : vector) {
+ sb << separator << rtc::ToString(element);
+ separator = ",";
}
- oss << "]";
- return oss.str();
+ sb << "]";
+ return sb.Release();
}
// Produces "[\"a\",\"b\",\"c\"]". Works for vectors of both const char* and
// std::string element types.
template <typename T>
std::string VectorOfStringsToString(const std::vector<T>& strings) {
- if (strings.empty())
- return "[]";
- std::ostringstream oss;
- oss << "[\"" << rtc::ToString(strings[0]) << '\"';
- for (size_t i = 1; i < strings.size(); ++i) {
- oss << ",\"" << rtc::ToString(strings[i]) << '\"';
+ rtc::StringBuilder sb;
+ sb << "[";
+ const char* separator = "";
+ for (const T& element : strings) {
+ sb << separator << "\"" << rtc::ToString(element) << "\"";
+ separator = ",";
}
- oss << "]";
- return oss.str();
+ sb << "]";
+ return sb.Release();
}
template <typename T>
std::string ToStringAsDouble(const T value) {
// JSON represents numbers as floating point numbers with about 15 decimal
// digits of precision.
- const int JSON_PRECISION = 16;
- std::ostringstream oss;
- oss << std::setprecision(JSON_PRECISION) << static_cast<double>(value);
- return oss.str();
+ char buf[32];
+ const int len = std::snprintf(&buf[0], arraysize(buf), "%.16g",
+ static_cast<double>(value));
+ RTC_DCHECK_LE(len, arraysize(buf));
+ return std::string(&buf[0], len);
}
template <typename T>
std::string VectorToStringAsDouble(const std::vector<T>& vector) {
- if (vector.empty())
- return "[]";
- std::ostringstream oss;
- oss << "[" << ToStringAsDouble<T>(vector[0]);
- for (size_t i = 1; i < vector.size(); ++i) {
- oss << "," << ToStringAsDouble<T>(vector[i]);
+ rtc::StringBuilder sb;
+ sb << "[";
+ const char* separator = "";
+ for (const T& element : vector) {
+ sb << separator << ToStringAsDouble<T>(element);
+ separator = ",";
}
- oss << "]";
- return oss.str();
+ sb << "]";
+ return sb.Release();
}
} // namespace
@@ -96,21 +98,21 @@
}
std::string RTCStats::ToJson() const {
- std::ostringstream oss;
- oss << "{\"type\":\"" << type() << "\","
- << "\"id\":\"" << id_ << "\","
- << "\"timestamp\":" << timestamp_us_;
+ rtc::StringBuilder sb;
+ sb << "{\"type\":\"" << type() << "\","
+ << "\"id\":\"" << id_ << "\","
+ << "\"timestamp\":" << timestamp_us_;
for (const RTCStatsMemberInterface* member : Members()) {
if (member->is_defined()) {
- oss << ",\"" << member->name() << "\":";
+ sb << ",\"" << member->name() << "\":";
if (member->is_string())
- oss << '"' << member->ValueToJson() << '"';
+ sb << "\"" << member->ValueToJson() << "\"";
else
- oss << member->ValueToJson();
+ sb << member->ValueToJson();
}
}
- oss << "}";
- return oss.str();
+ sb << "}";
+ return sb.Release();
}
std::vector<const RTCStatsMemberInterface*> RTCStats::Members() const {
diff --git a/stats/rtcstatsreport.cc b/stats/rtcstatsreport.cc
index df27909..a62a97a 100644
--- a/stats/rtcstatsreport.cc
+++ b/stats/rtcstatsreport.cc
@@ -10,11 +10,11 @@
#include "api/stats/rtcstatsreport.h"
-#include <sstream>
#include <type_traits>
#include <utility>
#include "rtc_base/checks.h"
+#include "rtc_base/strings/string_builder.h"
namespace webrtc {
@@ -119,16 +119,17 @@
}
std::string RTCStatsReport::ToJson() const {
- std::ostringstream oss;
- ConstIterator it = begin();
- if (it != end()) {
- oss << '[' << it->ToJson();
- for (++it; it != end(); ++it) {
- oss << "," << it->ToJson();
- }
- oss << ']';
+ if (begin() == end()) {
+ return "";
}
- return oss.str();
+ rtc::StringBuilder sb;
+ sb << "[";
+ const char* separator = "";
+ for (ConstIterator it = begin(); it != end(); ++it) {
+ sb << separator << it->ToJson();
+ }
+ sb << "]";
+ return sb.Release();
}
} // namespace webrtc
