Client to Server: send diffs instead of whole file

5 files changed, 76 insertions, 27 deletions

diff --git a/diff.cpp b/diff.cpp
index 99a2f14..b56fd51 100644
--- a/diff.cpp
+++ b/diff.cpp
@@ -1,6 +1,7 @@
 #include "diff.h"
 
 #include <algorithm>
+#include <iostream>
 #include <sstream>
 
 #include <boost/property_tree/xml_parser.hpp>
@@ -102,6 +103,22 @@ void Diff::create(const std::string& old_version, const std::string& new_version
  m_data = new_version.substr(old_pos0, new_pos1 - new_pos0);
 }
 
+Diff::Diff(const boost::property_tree::ptree& ptree)
+{
+ create(ptree);
+}
+
+void Diff::create(const boost::property_tree::ptree& ptree)
+{
+ m_pos0 = ptree.get<int>("diff.start");
+ m_pos1 = ptree.get<int>("diff.end");
+
+ if (m_pos0 > m_pos1)
+  throw std::runtime_error("Bad range in diff");
+
+ m_data = ptree.get<std::string>("diff.data");
+}
+
 Diff::Diff(const std::string& xml)
 {
  create(xml);
@@ -109,17 +126,11 @@ Diff::Diff(const std::string& xml)
 
 void Diff::create(const std::string& xml)
 {
- pt::ptree tree;
+ pt::ptree ptree;
  std::istringstream ss{xml};
- pt::read_xml(ss, tree, pt::xml_parser::no_comments | pt::xml_parser::trim_whitespace);
-
- m_pos0 = tree.get<int>("diff.start");
- m_pos1 = tree.get<int>("diff.end");
-
- if (m_pos0 > m_pos1)
-  throw std::runtime_error("Bad range in diff");
+ pt::read_xml(ss, ptree, pt::xml_parser::no_comments | pt::xml_parser::trim_whitespace);
 
- m_data = tree.get<std::string>("diff.data");
+ create(ptree);
 }
 
 boost::property_tree::ptree Diff::get_structure() const
diff --git a/diff.h b/diff.h
index fbf09b1..09d0936 100644
--- a/diff.h
+++ b/diff.h
@@ -11,6 +11,9 @@ public:
  Diff(const std::string& old_version, const std::string& new_version);
  void create(const std::string& old_version, const std::string& new_version);
 
+ Diff(const boost::property_tree::ptree& ptree);
+ void create(const boost::property_tree::ptree& ptree);
+
  Diff(const std::string& xml);
  void create(const std::string& xml);
 
diff --git a/html/whiteboard.js b/html/whiteboard.js
index aef4391..58023fe 100644
--- a/html/whiteboard.js
+++ b/html/whiteboard.js
@@ -4,6 +4,8 @@ function init() {
 }
 
 var revision;
+var baseline = ""; // data contents relating to revision, acknowledged by server
+var baseline_candidate = ""; // will become baseline, after ack by server
 
 // helper for breaking feedback loop
 var caretpos = 0;
@@ -42,6 +44,7 @@ function on_getfile(data, rev, pos)
 		board.value = data;
 	}
 	revision = rev;
+        baseline = data;
 	textAreaSetPos("board", pos);
 }
 
@@ -72,6 +75,7 @@ function on_version(version)
 function on_modify_ack(rev)
 {
 	revision = rev;
+        baseline = baseline_candidate;
 }
 
 function on_message(e) {
@@ -158,9 +162,6 @@ function init_board() {
 	Module.onRuntimeInitialized = () => {
          connect_websocket();
         };
-	//Module.onRuntimeInitialized = () => { alert("DEBUG: " + Module._getnum(1) + " " + UTF8ToString(Module._getstring(allocateUTF8("abc"))));
-		//_free(allocateUTF8("abc"));
-	//};
 	
 	var board = document.getElementById("board");
 	board.addEventListener("input", function() {on_input(); });
@@ -219,7 +220,25 @@ function on_input()
 	dataElement.appendChild(document.createTextNode(document.getElementById("board").value));
 	requestElement.appendChild(dataElement);
 
-	var posElement = xmlDocument.createElement("pos");
+        baseline_candidate = document.getElementById("board").value;
+
+	var revisionElement = xmlDocument.createElement("baserev");
+	revisionElement.appendChild(document.createTextNode(revision));
+	requestElement.appendChild(revisionElement);
+	
+	//Module.onRuntimeInitialized = () => { alert("DEBUG: " + Module._getnum(1) + " " + UTF8ToString(Module._getstring(allocateUTF8("abc"))));
+		//_free(allocateUTF8("abc"));
+	//};
+        var old_version = allocateUTF8(baseline);
+        var new_version = allocateUTF8(baseline_candidate);
+        var diff = Module._diff_create(old_version, new_version);
+        var diffDocument = parser.parseFromString(UTF8ToString(diff), "text/xml");
+        _free(old_version);
+        _free(new_version);
+        _free(diff);
+	requestElement.appendChild(xmlDocument.importNode(diffDocument.getElementsByTagName("diff")[0], true));
+	
+        var posElement = xmlDocument.createElement("pos");
 	posElement.appendChild(document.createTextNode(document.getElementById("board").selectionStart));
 	requestElement.appendChild(posElement);
 
diff --git a/webassembly/Makefile b/webassembly/Makefile
index e2898e4..df81e19 100644
--- a/webassembly/Makefile
+++ b/webassembly/Makefile
@@ -5,10 +5,17 @@ OBJS=diff.o
 
 CXX=em++
 
-CXXFLAGS=-I/usr/include -std=c++20
+CXXFLAGS=-I./include -O2 -std=c++20
 LDFLAGS=-s WASM=1 -s LINKABLE=1 -s EXPORT_ALL=1
+
 default: $(TARGET)
 
+$(OBJS): include
+
+include:
+	mkdir include
+	cp -r /usr/include/boost include/boost
+
 $(TARGET): $(OBJS)
 	$(CXX) $(LDFLAGS) $(OBJS) -o $(TARGETJS)
 	cp $(TARGETJS) $(TARGET) ../html/
@@ -18,3 +25,4 @@ diff.o: ../diff.cpp
 
 clean:
 	-rm -f *.o *.js *.wasm *.html
+	-rm -rf include
diff --git a/whiteboard.cpp b/whiteboard.cpp
index b84f7cc..059571d 100644
--- a/whiteboard.cpp
+++ b/whiteboard.cpp
@@ -39,6 +39,7 @@
 #include "libreichwein/xml.h"
 
 #include "config.h"
+#include "diff.h"
 #include "qrcode.h"
 #include "storage.h"
 
@@ -151,20 +152,27 @@ std::string Whiteboard::handle_request(Whiteboard::connection& c, const std::str
 
   if (command == "modify") {
    std::string id {xml.get<std::string>("request.id")};
-   std::string data {xml.get<std::string>("request.data")};
-   if (m_storage->getDocument(id) != data) {
-    m_storage->setDocument(id, data);
-    m_registry.setId(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)) }});
+   
+   int baserev {xml.get<int>("request.baserev")};
+   if (baserev != m_storage->getRevision(id))
+    return make_xml({{"type", "error"}, {"message", "Bad base revision ("s + std::to_string(baserev) + "). Current: "s + std::to_string(m_storage->getRevision(id)) }});
+
+   pt::ptree ptree;
+   ptree.put_child("diff", xml.get_child("request.diff"));
+   Diff d{ptree};
+   std::string data {m_storage->getDocument(id)};
+   data = d.apply(data);
+
+   m_storage->setDocument(id, data);
+   m_registry.setId(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 {};
+   return make_xml({{"type", "modify"}, {"revision", std::to_string(m_storage->getRevision(id)) }});
   } else if (command == "cursorpos") {
    std::string id {xml.get<std::string>("request.id")};
    int pos {xml.get<int>("request.pos")};