[wpiutil] Add MIME type utility (#2608)

Co-authored-by: Zhiquan Yeo <zyeo8@bloomberg.net>

wpiutil/src/main/native/cpp/MimeTypes.cpp

@@ -0,0 +1,71 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2020 FIRST. 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "wpi/MimeTypes.h"
+
+#include "wpi/StringMap.h"
+
+namespace wpi {
+
+// derived partially from
+// https://github.com/DEGoodmanWilson/libmime/blob/stable/0.1.2/mime/mime.cpp
+StringRef MimeTypeFromPath(StringRef path) {
+  // https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types
+  static StringMap<const char*> mimeTypes{
+      // text
+      {"css", "text/css"},
+      {"csv", "text/csv"},
+      {"htm", "text/html"},
+      {"html", "text/html"},
+      {"js", "text/javascript"},
+      {"json", "application/json"},
+      {"map", "application/json"},
+      {"md", "text/markdown"},
+      {"txt", "text/plain"},
+      {"xml", "text/xml"},
+
+      // images
+      {"apng", "image/apng"},
+      {"bmp", "image/bmp"},
+      {"gif", "image/gif"},
+      {"cur", "image/x-icon"},
+      {"ico", "image/x-icon"},
+      {"jpg", "image/jpeg"},
+      {"jpeg", "image/jpeg"},
+      {"png", "image/png"},
+      {"svg", "image/svg+xml"},
+      {"tif", "image/tiff"},
+      {"tiff", "image/tiff"},
+      {"webp", "image/webp"},
+
+      // fonts
+      {"otf", "font/otf"},
+      {"ttf", "font/ttf"},
+      {"woff", "font/woff"},
+
+      // misc
+      {"pdf", "application/pdf"},
+      {"zip", "application/zip"},
+  };
+
+  static const char* defaultType = "application/octet-stream";
+
+  auto pos = path.find_last_of("/");
+  if (pos != StringRef::npos) {
+    path = path.substr(pos + 1);
+  }
+  auto dot_pos = path.find_last_of(".");
+  if (dot_pos > 0 && dot_pos != StringRef::npos) {
+    auto type = mimeTypes.find(path.substr(dot_pos + 1));
+    if (type != mimeTypes.end()) {
+      return type->getValue();
+    }
+  }
+  return defaultType;
+}
+
+}  // namespace wpi