Added diff.cpp

13 files changed, 283 insertions, 32 deletions

diff --git a/Makefile b/Makefile
index 658e764..449e915 100755
--- a/Makefile
+++ b/Makefile
@@ -9,11 +9,10 @@ include common.mk
 PROJECTNAME=whiteboard
 
 DISTROS=base debian11 ubuntu2210
-VERSION=$(shell dpkg-parsechangelog --show-field Version)
 TGZNAME=$(PROJECTNAME)-$(VERSION).tar.xz
 
 INCLUDES=-I.
-HEADERS=config.h qrcode.h storage.h whiteboard.h compiledsql.h connectionregistry.h
+HEADERS=config.h qrcode.h storage.h whiteboard.h compiledsql.h connectionregistry.h diff.h
 SOURCES=$(HEADERS:.h=.cpp)
 OBJECTS=$(HEADERS:.h=.o)
 TARGETS=whiteboard
diff --git a/common.mk b/common.mk
index 1f4c2df..5f4c77c 100644
--- a/common.mk
+++ b/common.mk
@@ -61,3 +61,11 @@ LIBS+=-lboost_filesystem -lpthread
 LIBS+=-lSQLiteCpp $(shell pkg-config --libs qrcodegencpp GraphicsMagick++ fmt sqlite3)
 LIBS+=-lreichwein
 
+SRC_ROOT=$(shell echo $(MAKEFILE_LIST) | tr " " "\n" | grep common.mk | sed -e 's/\([^ ]*\)common.mk/\1/g')
+ifeq ($(SRC_ROOT),)
+SRC_ROOT=.
+endif
+
+VERSION=$(shell dpkg-parsechangelog --show-field Version --file $(SRC_ROOT)/debian/changelog)
+CXXFLAGS+=-DWHITEBOARD_VERSION=\"$(VERSION)\"
+
diff --git a/connectionregistry.cpp b/connectionregistry.cpp
index 1e48a96..11a538b 100644
--- a/connectionregistry.cpp
+++ b/connectionregistry.cpp
@@ -61,7 +61,7 @@ std::unordered_set<ConnectionRegistry::connection>::iterator ConnectionRegistry:
  return m_ids.at(id).end();
 }
 
-void ConnectionRegistry::dump()
+void ConnectionRegistry::dump() const
 {
  std::cout << "Connection Registry:" << std::endl;
  
diff --git a/connectionregistry.h b/connectionregistry.h
index 2b14553..cdd30d9 100644
--- a/connectionregistry.h
+++ b/connectionregistry.h
@@ -30,7 +30,7 @@ public:
  std::unordered_set<connection>::iterator begin(const std::string& id);
  std::unordered_set<connection>::iterator end(const std::string& id);
 
- void dump();
+ void dump() const;
 
  class RegistryGuard
  {
diff --git a/debian/changelog b/debian/changelog
index 8373568..2c990d1 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,6 +1,10 @@
 whiteboard (1.5) UNRELEASED; urgency=medium
 
   * Move from FCGI to websocket interface
+  * Position changes w/o file transmit
+  * Print version on main page
+  * Add reconnect button
+  * Add diff handling
 
  -- Roland Reichwein <mail@reichwein.it>  Sat, 21 Jan 2023 18:18:37 +0100
 
diff --git a/diff.cpp b/diff.cpp
new file mode 100644
index 0000000..b3ed5ce
--- /dev/null
+++ b/diff.cpp
@@ -0,0 +1,125 @@
+#include "diff.h"
+
+#include <algorithm>
+#include <sstream>
+
+#include <boost/property_tree/xml_parser.hpp>
+
+namespace pt = boost::property_tree;
+
+Diff::Diff()
+{
+}
+
+Diff::Diff(const std::string& old_version, const std::string& new_version)
+{
+ create(old_version, new_version);
+}
+
+std::string Diff::apply(const std::string& old_version) const
+{
+ std::string result{old_version};
+
+ result.erase(m_pos0, m_pos1 - m_pos0);
+
+ result.insert(m_pos0, m_data);
+ 
+ return result;
+}
+
+void Diff::create(const std::string& old_version, const std::string& new_version)
+{
+ auto front_mismatch{std::mismatch(old_version.cbegin(), old_version.cend(), new_version.cbegin(), new_version.cend())};
+ std::string::difference_type old_pos0 {front_mismatch.first - old_version.cbegin()};
+ auto& new_pos0 {old_pos0};
+
+ // equal
+ if (old_pos0 == old_version.size() && new_pos0 == new_version.size()) {
+  m_pos0 = 0;
+  m_pos1 = 0;
+  m_data.clear();
+  return;
+ }
+
+ // append at end
+ if (old_pos0 == old_version.size()) {
+  m_pos0 = old_pos0;
+  m_pos1 = old_pos0;
+  m_data = new_version.substr(new_pos0);
+  return;
+ }
+
+ // remove from end
+ if (new_pos0 == new_version.size()) {
+  m_pos0 = old_pos0;
+  m_pos1 = old_version.size();
+  m_data.clear();
+  return;
+ }
+
+ auto back_mismatch{std::mismatch(old_version.crbegin(), old_version.crend(), new_version.crbegin(), new_version.crend())};
+ // i.e. the indices starting from which we can assume equality
+ size_t old_pos1 {old_version.size() - (back_mismatch.first - old_version.crbegin())};
+ size_t new_pos1 {new_version.size() - (back_mismatch.second - new_version.crbegin())};
+
+ // complete equality is already handled above
+ 
+ // insert at start
+ if (old_pos1 == 0) {
+  m_pos0 = 0;
+  m_pos1 = 0;
+  m_data = new_version.substr(0, new_pos1);
+  return;
+ }
+
+ // remove from start
+ if (new_pos1 == 0) {
+  m_pos0 = 0;
+  m_pos1 = old_pos1;
+  m_data.clear();
+  return;
+ }
+
+ // insert in the middle
+ if (old_pos0 == old_pos1) {
+  m_pos0 = old_pos0;
+  m_pos1 = old_pos0;
+  m_data = new_version.substr(new_pos0, new_pos1 - new_pos0);
+  return;
+ }
+ 
+ // remove from the middle
+ if (new_pos0 == new_pos1) {
+  m_pos0 = old_pos0;
+  m_pos1 = old_pos1;
+  m_data.clear();
+  return;
+ }
+
+ // last resort: remove and add in the middle
+ m_pos0 = old_pos0;
+ m_pos1 = old_pos1;
+ m_data = new_version.substr(old_pos0, new_pos1 - new_pos0);
+}
+
+boost::property_tree::ptree Diff::get_structure() const
+{
+ pt::ptree ptree;
+ ptree.put("diff.chunk.start", std::to_string(m_pos0));
+ ptree.put("diff.chunk.end", std::to_string(m_pos1));
+ ptree.put("diff.chunk.data", m_data);
+
+ return ptree;
+}
+
+std::string Diff::get_xml() const
+{
+ pt::ptree ptree{get_structure()};
+
+ std::ostringstream oss;
+ // write_xml_element instead of write_xml to omit <!xml...> header
+ //pt::xml_parser::write_xml(oss, xml);
+ pt::xml_parser::write_xml_element(oss, {}, ptree, -1, boost::property_tree::xml_writer_settings<pt::ptree::key_type>{});
+ return oss.str();
+}
+
diff --git a/diff.h b/diff.h
new file mode 100644
index 0000000..0193238
--- /dev/null
+++ b/diff.h
@@ -0,0 +1,24 @@
+#pragma once
+
+#include <string>
+
+#include <boost/property_tree/ptree.hpp>
+
+class Diff
+{
+public:
+ Diff();
+ Diff(const std::string& old_version, const std::string& new_version);
+
+ std::string apply(const std::string& old_version) const;
+ void create(const std::string& old_version, const std::string& new_version);
+
+ boost::property_tree::ptree get_structure() const;
+ std::string get_xml() const;
+
+private:
+ // diff replaces space from m_pos0 (inclusive) to m_pos1 (exclusive) with m_data
+ size_t m_pos0{};
+ size_t m_pos1{};
+ std::string m_data;
+};
diff --git a/html/index.html b/html/index.html
index f06ea01..4d1fb2a 100644
--- a/html/index.html
+++ b/html/index.html
@@ -19,10 +19,12 @@
 			<br/>
 			<br/>
 			<button class="button" onclick="on_new_page();">New page</button>
-			<button class="button" onclick="on_qrcode();">QR code</button>
+			<button class="button" onclick="on_qrcode_click();">QR code</button>
+			<span id="connecting">Connecting...</span>
+			<button class="buttonred" id="reconnect" onclick="on_reconnect_click();" hidden>Reconnect</button>
 			<br/>
 			<br/>
-			Reichwein.IT Whiteboard by <a href="https://www.reichwein.it">https://www.reichwein.it</a><br/>
+                        Reichwein.IT Whiteboard <span id="version"></span> by <a href="https://www.reichwein.it">https://www.reichwein.it</a><br/>
 		</div>
 
 		<a id="download-a" hidden></a>
diff --git a/html/whiteboard.css b/html/whiteboard.css
index 55e68cf..4de9b46 100644
--- a/html/whiteboard.css
+++ b/html/whiteboard.css
@@ -1,5 +1,5 @@
 body {
-	font-family: "sans-serif";
+	font-family: sans-serif;
 }
 
 figcaption {
@@ -100,6 +100,17 @@ img.banner {
 	cursor: pointer;
 }
 
+.buttonred {
+        color:#FFFFFF;
+        background-color:#B05050;
+        text-decoration: none;
+        padding: 15px 20px;
+        font-size: 16px;
+        border: none;
+        border-radius: 6px;
+	cursor: pointer;
+}
+
 @media only screen and (min-width: 1px) and (max-width: 630px) {
 
 .qrwindow {
diff --git a/html/whiteboard.js b/html/whiteboard.js
index 9610468..83601b8 100644
--- a/html/whiteboard.js
+++ b/html/whiteboard.js
@@ -30,8 +30,13 @@ function on_getfile(data, rev, pos)
 	if (board.value != data) {
 		board.value = data;
 	}
-	textAreaSetPos("board", pos);
 	revision = rev;
+	textAreaSetPos("board", pos);
+}
+
+function on_getpos(pos)
+{
+	textAreaSetPos("board", pos);
 }
 
 function on_newid(id)
@@ -42,13 +47,17 @@ function on_newid(id)
 
 function on_qrcode(png)
 {
-	var blob = new Blob([png], {type: 'image/png'});
-	var url = URL.createObjectURL(blob);
+	var url = "data:image/png;base64," + png;
 	var img = document.getElementById("qrcode");
 	img.src = url;
 	showQRWindow();
 }
 
+function on_version(version)
+{
+	document.getElementById("version").textContent = version;
+}
+
 function on_modify_ack(rev)
 {
 	revision = rev;
@@ -63,13 +72,17 @@ function on_message(e) {
 	if (type == "getfile") {
 		on_getfile(xmlDocument.getElementsByTagName("data")[0].textContent,
 			   parseInt(xmlDocument.getElementsByTagName("revision")[0].textContent),
-			   parseInt(xmlDocument.getElementsByTagName("cursorpos")[0].textContent));
+		           parseInt(xmlDocument.getElementsByTagName("pos")[0].textContent));
+	} else if (type == "getpos") {
+		on_getpos(parseInt(xmlDocument.getElementsByTagName("pos")[0].textContent));
 	} else if (type == "modify") {
 		on_modify_ack(parseInt(xmlDocument.getElementsByTagName("revision")[0].textContent));
 	} else if (type == "newid") {
 		on_newid(xmlDocument.getElementsByTagName("id")[0].textContent);
 	} else if (type == "qrcode") {
 		on_qrcode(xmlDocument.getElementsByTagName("png")[0].textContent);
+	} else if (type == "version") {
+		on_version(xmlDocument.getElementsByTagName("version")[0].textContent);
 	} else if (type == "error") {
 		alert(xmlDocument.getElementsByTagName("message")[0].textContent);
 	} else {
@@ -88,12 +101,15 @@ function handleSelection() {
   }
 }
 
-function init_board() {
+function connect_websocket() {
+	document.getElementById("reconnect").style.display = 'none';
+	document.getElementById("connecting").style.display = 'block';
 	var newlocation = location.origin + location.pathname;
 	newlocation = newlocation.replace(/^http/, 'ws');
 	if (newlocation.slice(-1) != "/")
 		newlocation += "/";
 	newlocation += "websocket";
+
 	websocket = new WebSocket(newlocation);
 
 	websocket.onmessage = function(e) { on_message(e); };
@@ -105,24 +121,37 @@ function init_board() {
 			return;
 		}
 
-		var board = document.getElementById("board");
-		board.addEventListener("input", function() {on_input(); });
-                // Need this workaround (different from direct on_selectionchange) for Chrome.
-		// Otherwise, callback will not be called on Chrome.
-		document.addEventListener("selectionchange", handleSelection);
-		//board.addEventListener("selectionchange", function() {on_selectionchange(); });
-
+		websocket.send("<request><command>getversion</command></request>");
 		websocket.send("<request><command>getfile</command><id>" + get_id() + "</id></request>");
+		document.getElementById("connecting").style.display = 'none';
 	};
 	
 	websocket.onclose = function(e) {
 		alert("Server connection closed.");
+		document.getElementById("reconnect").style.display = 'inline';
 	};
 
 	websocket.onerror = function(e) {
 		alert("Error: Server connection closed.");
+		document.getElementById("reconnect").style.display = 'inline';
 	};
 
+}
+
+function on_reconnect_click() {
+	connect_websocket();
+}
+
+function init_board() {
+	connect_websocket();
+	
+	var board = document.getElementById("board");
+	board.addEventListener("input", function() {on_input(); });
+	// Need this workaround (different from direct on_selectionchange) for Chrome.
+	// Otherwise, callback will not be called on Chrome.
+	document.addEventListener("selectionchange", handleSelection);
+	//board.addEventListener("selectionchange", function() {on_selectionchange(); });
+
         document.getElementById("qrwindow").onclick = function() {
          hideQRWindow();
         }
@@ -173,6 +202,10 @@ function on_input()
 	dataElement.appendChild(document.createTextNode(document.getElementById("board").value));
 	requestElement.appendChild(dataElement);
 
+	var posElement = xmlDocument.createElement("pos");
+	posElement.appendChild(document.createTextNode(document.getElementById("board").selectionStart));
+	requestElement.appendChild(posElement);
+
 	websocket.send(new XMLSerializer().serializeToString(xmlDocument));
 }
 
@@ -192,9 +225,9 @@ function on_selectionchange(pos)
 	idElement.appendChild(document.createTextNode(get_id()));
 	requestElement.appendChild(idElement);
 
-	var dataElement = xmlDocument.createElement("pos");
-	dataElement.appendChild(document.createTextNode(pos));
-	requestElement.appendChild(dataElement);
+	var posElement = xmlDocument.createElement("pos");
+	posElement.appendChild(document.createTextNode(pos));
+	requestElement.appendChild(posElement);
 
 	websocket.send(new XMLSerializer().serializeToString(xmlDocument));
 }
@@ -209,7 +242,7 @@ function textAreaSetPos(id, pos)
 }
 
 // HTML button
-function on_qrcode()
+function on_qrcode_click()
 {
 	var parser = new DOMParser();
 	var xmlDocument = parser.parseFromString("<request></request>", "text/xml");
diff --git a/tests/Makefile b/tests/Makefile
index 15e4106..c4109d5 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -11,7 +11,7 @@ CXXFLAGS+=--coverage
 LDFLAGS+=--coverage
 endif
 
-UNITS=storage.cpp config.cpp compiledsql.cpp qrcode.cpp whiteboard.cpp connectionregistry.cpp
+UNITS=storage.cpp config.cpp compiledsql.cpp qrcode.cpp whiteboard.cpp connectionregistry.cpp diff.cpp
 
 UNITTESTS=test-config.cpp \
 	  test-storage.cpp \
@@ -52,6 +52,9 @@ config.o: ../config.cpp
 connectionregistry.o: ../connectionregistry.cpp
 	$(CXX) $(CXXFLAGS) -o $@ -c $<
 
+diff.o: ../diff.cpp
+	$(CXX) $(CXXFLAGS) -o $@ -c $<
+
 storage.o: ../storage.cpp
 	$(CXX) $(CXXFLAGS) -o $@ -c $<
 
diff --git a/whiteboard.cpp b/whiteboard.cpp
index b15ebbe..df18242 100644
--- a/whiteboard.cpp
+++ b/whiteboard.cpp
@@ -34,6 +34,7 @@
 
 #include <fmt/core.h>
 
+#include "libreichwein/base64.h"
 #include "libreichwein/file.h"
 
 #include "config.h"
@@ -89,11 +90,12 @@ std::string make_xml(const std::initializer_list<std::pair<std::string, std::str
 
  std::ostringstream oss;
  // write_xml_element instead of write_xml to omit <!xml...> header
+ //pt::xml_parser::write_xml(oss, xml);
  pt::xml_parser::write_xml_element(oss, {}, xml, -1, boost::property_tree::xml_writer_settings<pt::ptree::key_type>{});
  return oss.str();
 }
 
-void Whiteboard::notify_other_connections(Whiteboard::connection& c, const std::string& id)
+void Whiteboard::notify_other_connections_file(Whiteboard::connection& c, const std::string& id)
 {
  std::for_each(m_registry.begin(id), m_registry.end(id), [&](const Whiteboard::connection& ci)
                {
@@ -103,13 +105,34 @@ void Whiteboard::notify_other_connections(Whiteboard::connection& c, const std::
                    {"type", "getfile"},
                    {"data", m_storage->getDocument(id)},
                    {"revision", std::to_string(m_storage->getRevision(id)) },
-                   {"cursorpos", std::to_string(m_storage->getCursorPos(id)) }
+                   {"pos", std::to_string(m_storage->getCursorPos(id)) }
                    });
                  std::lock_guard<std::mutex> lock(m_websocket_mutex);
                  try {
                   ci->write(buffer.data());
                  } catch (const std::exception& ex) {
-                  std::cerr << "Warning: Notify write for " << ci << " not possible, id " << id << std::endl;
+                  std::cerr << "Warning: Notify getfile write for " << ci << " not possible, id " << id << std::endl;
+                  m_registry.dump();
+                 }
+                }
+               });
+}
+
+void Whiteboard::notify_other_connections_pos(Whiteboard::connection& c, const std::string& id)
+{
+ std::for_each(m_registry.begin(id), m_registry.end(id), [&](const Whiteboard::connection& ci)
+               {
+                if (c != ci) {
+                 boost::beast::flat_buffer buffer;
+                 boost::beast::ostream(buffer) << make_xml({
+                   {"type", "getpos"},
+                   {"pos", std::to_string(m_storage->getCursorPos(id)) }
+                   });
+                 std::lock_guard<std::mutex> lock(m_websocket_mutex);
+                 try {
+                  ci->write(buffer.data());
+                 } catch (const std::exception& ex) {
+                  std::cerr << "Warning: Notify getpos write for " << ci << " not possible, id " << id << std::endl;
                   m_registry.dump();
                  }
                 }
@@ -135,7 +158,13 @@ std::string Whiteboard::handle_request(Whiteboard::connection& c, const std::str
    if (m_storage->getDocument(id) != data) {
     m_storage->setDocument(id, data);
     m_registry.setId(c, id);
-    notify_other_connections(c, id);
+    notify_other_connections_file(c, id);
+    
+    int pos {xml.get<int>("request.pos")};
+    if (m_storage->getCursorPos(id) != pos) {
+     m_storage->setCursorPos(id, pos);
+     notify_other_connections_pos(c, id);
+    }
     return make_xml({{"type", "modify"}, {"revision", std::to_string(m_storage->getRevision(id)) }});
    }
    return {};
@@ -144,7 +173,7 @@ std::string Whiteboard::handle_request(Whiteboard::connection& c, const std::str
    int pos {xml.get<int>("request.pos")};
    if (m_storage->getCursorPos(id) != pos) {
     m_storage->setCursorPos(id, pos);
-    notify_other_connections(c, id);
+    notify_other_connections_pos(c, id);
    }
    return {};
   } else if (command == "getfile") {
@@ -165,7 +194,14 @@ std::string Whiteboard::handle_request(Whiteboard::connection& c, const std::str
                    {"type", "getfile"},
                    {"data", filedata},
                    {"revision", std::to_string(m_storage->getRevision(id)) },
-                   {"cursorpos", std::to_string(m_storage->getCursorPos(id)) }
+                   {"pos", std::to_string(m_storage->getCursorPos(id)) }
+                   }); 
+  } else if (command == "getpos") {
+   std::string id {xml.get<std::string>("request.id")};
+
+   return make_xml({
+                   {"type", "getpos"},
+                   {"pos", std::to_string(m_storage->getCursorPos(id)) }
                    }); 
   } else if (command == "newid") {
    return make_xml({{"type", "newid"}, {"id", m_storage->generate_id()}}); 
@@ -177,7 +213,12 @@ std::string Whiteboard::handle_request(Whiteboard::connection& c, const std::str
 
    std::string pngdata {QRCode::getQRCode(url)};
 
-   return make_xml({{"type", "qrcode"}, {"png", pngdata}}); 
+   return make_xml({{"type", "qrcode"}, {"png", Reichwein::Base64::encode64(pngdata)}});
+  } else if (command == "getversion") {
+   return make_xml({
+                   {"type", "version"},
+                   {"version", WHITEBOARD_VERSION }
+                   }); 
   } else {
    throw std::runtime_error("Bad command: "s + command);
   }
diff --git a/whiteboard.h b/whiteboard.h
index e39b94e..818fcfe 100644
--- a/whiteboard.h
+++ b/whiteboard.h
@@ -27,7 +27,8 @@ private:
  
  using connection = std::shared_ptr<boost::beast::websocket::stream<boost::asio::ip::tcp::socket>>;
  std::string handle_request(connection& c, const std::string& request);
- void notify_other_connections(connection& c, const std::string& id); // notify all other id-related connections about changes
+ void notify_other_connections_file(connection& c, const std::string& id); // notify all other id-related connections about changes
+ void notify_other_connections_pos(connection& c, const std::string& id); // notify all other id-related connections about changes
  void do_session(boost::asio::ip::tcp::socket socket);
  void storage_cleanup();
 };