Start implementing HttpCamera.

This is a work in progress that does not yet support camera settings.

src/HttpUtil.h

@@ -8,12 +8,18 @@
 #ifndef CS_HTTPUTIL_H_
 #define CS_HTTPUTIL_H_
 
-#include "llvm/SmallVector.h"
-#include "llvm/StringRef.h"
+#include <memory>
+#include <string>
 
-namespace wpi {
-class raw_istream;
-}
+#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 cs {
 
@@ -40,6 +46,105 @@ llvm::StringRef UnescapeURI(llvm::StringRef str,
 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, llvm::StringRef cameraName);
+
+  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, llvm::StringRef cameraName);
+
+  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 cs
 
+#include "HttpUtil.inl"
+
 #endif  // CS_HTTPUTIL_H_