Add HTTP utilities. (#7)

Imported from cscore.

src/main/native/include/support/HttpUtil.inl

@@ -0,0 +1,48 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2015. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#ifndef WPIUTIL_SUPPORT_HTTPUTIL_INL_
+#define WPIUTIL_SUPPORT_HTTPUTIL_INL_
+
+namespace wpi {
+
+template <typename T>
+HttpRequest::HttpRequest(const HttpLocation& loc, const T& extraParams)
+    : host{loc.host}, port{loc.port} {
+  llvm::StringMap<llvm::StringRef> params;
+  for (const auto& p : loc.params)
+    params.insert(std::make_pair(GetFirst(p), GetSecond(p)));
+  for (const auto& p : extraParams)
+    params.insert(std::make_pair(GetFirst(p), GetSecond(p)));
+  SetPath(loc.path, params);
+  SetAuth(loc);
+}
+
+template <typename T>
+void HttpRequest::SetPath(llvm::StringRef path_, const T& params) {
+  // Build location including query string
+  llvm::raw_svector_ostream pathOs{path};
+  pathOs << path_;
+  bool first = true;
+  for (const auto& param : params) {
+    if (first) {
+      pathOs << '?';
+      first = false;
+    } else {
+      pathOs << '&';
+    }
+    llvm::SmallString<64> escapeBuf;
+    pathOs << EscapeURI(GetFirst(param), escapeBuf);
+    if (!GetSecond(param).empty()) {
+      pathOs << '=' << EscapeURI(GetSecond(param), escapeBuf);
+    }
+  }
+}
+
+}  // namespace wpi
+
+#endif  // WPIUTIL_SUPPORT_HTTPUTIL_INL_