Add HTTP utilities. (#7)

Imported from cscore.

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

@@ -0,0 +1,150 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2016. 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_H_
+#define WPIUTIL_SUPPORT_HTTPUTIL_H_
+
+#include <memory>
+#include <string>
+
+#include "llvm/ArrayRef.h"
+#include "llvm/SmallString.h"
+#include "llvm/SmallVector.h"
+#include "llvm/StringMap.h"
+#include "llvm/StringRef.h"
+#include "support/raw_istream.h"
+#include "support/raw_socket_istream.h"
+#include "support/raw_socket_ostream.h"
+#include "tcpsockets/NetworkStream.h"
+
+namespace wpi {
+
+// Read a line from an input stream (up to a maximum length).
+// The returned buffer will contain the trailing \n (unless the maximum length
+// was reached).  \r's are stripped from the buffer.
+// @param buf Buffer for output
+// @param error Set to true if an error occurred
+// @return Line
+llvm::StringRef ReadLine(wpi::raw_istream& is, llvm::SmallVectorImpl<char>& buf,
+                         int maxLen, bool* error);
+
+// Unescape a %xx-encoded URI.
+// @param buf Buffer for output
+// @param error Set to true if an error occurred
+// @return Escaped string
+llvm::StringRef UnescapeURI(llvm::StringRef str,
+                            llvm::SmallVectorImpl<char>& buf, bool* error);
+
+// Escape a string with %xx-encoding.
+// @param buf Buffer for output
+// @param spacePlus If true, encodes spaces to '+' rather than "%20"
+// @return Escaped string
+llvm::StringRef EscapeURI(llvm::StringRef str, llvm::SmallVectorImpl<char>& buf,
+                          bool spacePlus = true);
+
+// Parse a set of HTTP headers.  Saves just the Content-Type and Content-Length
+// fields.
+// @param is Input stream
+// @param contentType If not null, Content-Type contents are saved here.
+// @param contentLength If not null, Content-Length contents are saved here.
+// @return False if error occurred in input stream
+bool ParseHttpHeaders(wpi::raw_istream& is,
+                      llvm::SmallVectorImpl<char>* contentType,
+                      llvm::SmallVectorImpl<char>* contentLength);
+
+// Look for a MIME multi-part boundary.  On return, the input stream will
+// be located at the character following the boundary (usually "\r\n").
+// @param is Input stream
+// @param boundary Boundary string to scan for (not including "--" prefix)
+// @param saveBuf If not null, all scanned characters up to but not including
+//     the boundary are saved to this string
+// @return False if error occurred on input stream, true if boundary found.
+bool FindMultipartBoundary(wpi::raw_istream& is, llvm::StringRef boundary,
+                           std::string* saveBuf);
+
+class HttpLocation {
+ public:
+  HttpLocation() = default;
+  HttpLocation(llvm::StringRef url_, bool* error, std::string* errorMsg);
+
+  std::string url;  // retain copy
+  std::string user;  // unescaped
+  std::string password;  // unescaped
+  std::string host;
+  int port;
+  std::string path;  // escaped, not including leading '/'
+  std::vector<std::pair<std::string, std::string>> params;  // unescaped
+  std::string fragment;
+};
+
+class HttpRequest {
+ public:
+  HttpRequest() = default;
+
+  HttpRequest(const HttpLocation& loc) : host{loc.host}, port{loc.port} {
+    SetPath(loc.path, loc.params);
+    SetAuth(loc);
+  }
+
+  template <typename T>
+  HttpRequest(const HttpLocation& loc, const T& extraParams);
+
+  HttpRequest(const HttpLocation& loc, llvm::StringRef path_)
+      : host{loc.host}, port{loc.port}, path{path_} {
+    SetAuth(loc);
+  }
+
+  template <typename T>
+  HttpRequest(const HttpLocation& loc, llvm::StringRef path_, const T& params)
+      : host{loc.host}, port{loc.port} {
+    SetPath(path_, params);
+    SetAuth(loc);
+  }
+
+  llvm::SmallString<128> host;
+  int port;
+  std::string auth;
+  llvm::SmallString<128> path;
+
+ private:
+  void SetAuth(const HttpLocation& loc);
+  template <typename T>
+  void SetPath(llvm::StringRef path_, const T& params);
+
+  template <typename T>
+  static llvm::StringRef GetFirst(const T& elem) { return elem.first; }
+  template <typename T>
+  static llvm::StringRef GetFirst(const llvm::StringMapEntry<T>& elem) {
+    return elem.getKey();
+  }
+  template <typename T>
+  static llvm::StringRef GetSecond(const T& elem) { return elem.second; }
+};
+
+class HttpConnection {
+ public:
+  HttpConnection(std::unique_ptr<wpi::NetworkStream> stream_, int timeout)
+      : stream{std::move(stream_)}, is{*stream, timeout}, os{*stream, true} {}
+
+  bool Handshake(const HttpRequest& request, std::string* warnMsg);
+
+  std::unique_ptr<wpi::NetworkStream> stream;
+  wpi::raw_socket_istream is;
+  wpi::raw_socket_ostream os;
+
+  // Valid after Handshake() is successful
+  llvm::SmallString<64> contentType;
+  llvm::SmallString<64> contentLength;
+
+  explicit operator bool() const { return stream && !is.has_error(); }
+};
+
+}  // namespace wpi 
+
+#include "HttpUtil.inl"
+
+#endif  // WPIUTIL_SUPPORT_HTTPUTIL_H_

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_