From 321ad64a27517083859433f3b1f06116f1cded2a Mon Sep 17 00:00:00 2001
From: Scott Alfter <scott@alfter.us>
Date: Tue, 30 Mar 2021 22:52:47 -0700
Subject: [PATCH] range transfers for GET and PUT work...they seem more
 reliable on iffy power now, too

---
 ESPWebDAV.cpp | 63 ++++++++++++++++++++++++++++++++++++++++++---------
 WebSrv.cpp    | 16 ++++++-------
 2 files changed, 60 insertions(+), 19 deletions(-)

diff --git a/ESPWebDAV.cpp b/ESPWebDAV.cpp
index 1eb2916..ba81e85 100644
--- a/ESPWebDAV.cpp
+++ b/ESPWebDAV.cpp
@@ -110,6 +110,11 @@ void ESPWebDAV::handleRequest(String blank)	{
 	// add header that gets sent everytime
 	sendHeader("DAV", "1, 2");
 
+  // these headers are for webdavfs (https://github.com/miquels/webdavfs)
+  // pretend to be enough like Apache that we get read/write support
+  sendHeader("Server", "ESPWebDAV (use Apache put range)");
+  sendHeader("DAV", "<http://apache.org/dav/propset/fs/1>");
+
 	// handle properties
 	if(method.equals("PROPFIND"))
 		return handleProp(resource);
@@ -349,24 +354,56 @@ void ESPWebDAV::handleGet(ResourceType resource, bool isGet)	{
 	rFile.open(uri.c_str(), O_READ);
 
 	sendHeader("Allow", "PROPFIND,OPTIONS,DELETE,COPY,MOVE,HEAD,POST,PUT,GET");
-	size_t fileSize = rFile.fileSize();
-	setContentLength(fileSize);
+ 	size_t fileSize;
+ 	if (_contentRangeStart==CONTENT_RANGE_NOT_SET && _contentRangeEnd==CONTENT_RANGE_NOT_SET)
+ 	{
+ 	  fileSize=rFile.fileSize();
+ 	}
+ 	else
+ 	{
+ 	  fileSize=_contentRangeEnd-_contentRangeStart+1;
+    sendHeader("Accept-Ranges", "bytes");
+    sendHeader("Content-Range", "bytes "+String(_contentRangeStart)+"-"+String(_contentRangeEnd)+"/"+String(rFile.fileSize()));
+ 	}
+  setContentLength(fileSize);
+  
 	String contentType = getMimeType(uri);
 	if(uri.endsWith(".gz") && contentType != "application/x-gzip" && contentType != "application/octet-stream")
 		sendHeader("Content-Encoding", "gzip");
 
-	send("200 OK", contentType.c_str(), "");
+  if (!isGet)
+  	send("200 OK", contentType.c_str(), "");
+
+	if(isGet)	
+	{
 
-	if(isGet)	{
 		// disable Nagle if buffer size > TCP MTU of 1460
 		// client.setNoDelay(1);
 
-		// send the file
-		while(rFile.available())	{
-			// SD read speed ~ 17sec for 4.5MB file
-			int numRead = rFile.read(buf, sizeof(buf));
-			client.write(buf, numRead);
-		}
+    if (_contentRangeStart==CONTENT_RANGE_NOT_SET && _contentRangeEnd==CONTENT_RANGE_NOT_SET)
+    {
+      send("200 OK", contentType.c_str(), "");
+  		// send the whole file
+  		while(rFile.available())	
+  		{
+  			// SD read speed ~ 17sec for 4.5MB file
+  			int numRead = rFile.read(buf, sizeof(buf));
+  			client.write(buf, numRead);
+  		}
+    }
+    else
+    {
+      send("206 Partial Content", contentType.c_str(), "");
+      // send the selected range
+      rFile.seekSet(_contentRangeStart);
+      size_t remaining=fileSize;
+      while (remaining>0)
+      {
+        int numRead=rFile.read(buf, (sizeof(buf)<remaining)?sizeof(buf):remaining);
+        client.write(buf, numRead);
+        remaining-=numRead;
+      }
+    }
 	}
 
 	rFile.close();
@@ -458,6 +495,10 @@ void ESPWebDAV::handlePut(ResourceType resource)	{
 	}
 	else
 	{
+    // reopen file so we can seek within it
+    nFile.close();
+    nFile.open(uri.c_str(), O_RDWR);
+
 		// set up buffer
 		const size_t WRITE_BLOCK_CONST = 512;
 		uint8_t buf[WRITE_BLOCK_CONST];
@@ -465,7 +506,7 @@ void ESPWebDAV::handlePut(ResourceType resource)	{
 		size_t numRemaining = contentLen;
 
 		// seek to beginning of range
-		nFile.seekSet(_contentRangeStart);
+    nFile.seekSet(_contentRangeStart);
 
 		// update file
 		while (numRemaining>0)
diff --git a/WebSrv.cpp b/WebSrv.cpp
index 42c72e1..578048c 100644
--- a/WebSrv.cpp
+++ b/WebSrv.cpp
@@ -192,7 +192,7 @@ bool ESPWebDAV::parseRequest() {
 			contentLengthHeader = headerValue;
 		else if(headerName.equalsIgnoreCase("Destination"))
 			destinationHeader = headerValue;
-		else if (headerName.equalsIgnoreCase("Content-Range"))
+		else if (headerName.equalsIgnoreCase("Content-Range") || headerName.equalsIgnoreCase("Range"))
 		{
 			contentRangeHeader = headerValue;
 			_contentRangeStart = _contentRangeEnd = 0;
@@ -201,15 +201,15 @@ bool ESPWebDAV::parseRequest() {
 			{
 				if (headerValue.c_str()[i]=='-')
 				{
-				bDashReached=true;
-				break;
+  				bDashReached=true;
+				  continue;
 				}
 				if (headerValue.c_str()[i]>='0' && headerValue.c_str()[i]<='9')
 				{
-				if (!bDashReached)
-					_contentRangeStart=_contentRangeStart*10+(headerValue[i]-'0');
-				else
-					_contentRangeEnd=_contentRangeEnd*10+(headerValue[i]-'0');
+  				if (!bDashReached)
+  					_contentRangeStart=_contentRangeStart*10+(headerValue[i]-'0');
+  				else
+  					_contentRangeEnd=_contentRangeEnd*10+(headerValue[i]-'0');
 				}
 			}   
 		}
@@ -261,7 +261,7 @@ void ESPWebDAV::_prepareHeader(String& response, String code, const char* conten
 		sendHeader("Content-Length", String(_contentLength));
 	else if(_contentLength == CONTENT_LENGTH_UNKNOWN) {
 		_chunked = true;
-		sendHeader("Accept-Ranges","none");
+		sendHeader("Accept-Ranges","bytes");
 		sendHeader("Transfer-Encoding","chunked");
 	}
 	sendHeader("Connection", "close");