Initial community commit

Src/filereader/ProgressiveHTTPReader.cpp

@@ -0,0 +1,88 @@
+/** (c) Nullsoft, Inc.         C O N F I D E N T I A L
+ ** Filename: 
+ ** Project:
+ ** Description:
+ ** Author: Ben Allison benski@nullsoft.com
+ ** Created:
+ **/
+/* implementation ideas, notes and todos
+
+Memory mapped file to use as temporary storage
+mark downloaded pages with bitfield vector
+use content length header
+use content-disposition for filename, if available (instead of temp filename)
+
+*/
+#include "ProgressiveHTTPReader.h"
+#include <windows.h>
+
+int ProgressiveHTTPReader::isMine(const wchar_t *filename, int mode)
+{
+	return 0; // only want to use the progressive downloader/reader on demand.
+}
+
+int ProgressiveHTTPReader::open(const wchar_t *filename, int mode)
+{
+	pagePosition.QuadPart=0;
+
+	SYSTEM_INFO info;
+	GetSystemInfo(&info);
+	pageSize = info.dwPageSize;
+	
+  char tempPath[MAX_PATH];
+	GetTempPathA(MAX_PATH, tempPath);
+	GetTempFileNameA(tempPath, "phr", 0, tempPath);
+	
+	hFile=CreateFile((LPCWSTR)tempPath, GENERIC_WRITE|GENERIC_READ, 0, 0, CREATE_ALWAYS, 0, 0);
+
+	
+	LARGE_INTEGER contentLength;
+	contentLength.QuadPart = 100*1024*1024; // TODO: use content length header for filesize
+	
+	hMap=CreateFileMapping(hFile, 0, PAGE_READWRITE, contentLength.HighPart, contentLength.LowPart, 0);
+	// TODO: spawn a thread and start downloading data..
+	// thread should get a duplicate file handle
+
+	return 1;
+}
+
+void ProgressiveHTTPReader::IncrementPosition(uint64_t inc)
+{
+	pagePosition.QuadPart += offset;
+	pagePosition.QuadPart += inc;
+	offset = (uint32_t)(pagePosition.QuadPart & (uint64_t)pageSize);
+	pagePosition.QuadPart-=offset;
+}
+
+size_t ProgressiveHTTPReader::GetPageNumber() const
+{
+	return (size_t)(pagePosition.QuadPart / (uint64_t)pageSize);
+}
+
+size_t ProgressiveHTTPReader::read(__int8 *buffer, size_t length)
+{
+	/* TODO:
+	   is this area of the file downloaded yet?  If so, just return it as is
+		 otherwise, what should we do?  return what we can?  or sit and wait until we get the data?
+		 */
+	while (length)
+	{
+		// if page is available
+		{
+			// TODO: calculate maximum length we can map
+			MapViewOfFile(hMap, FILE_MAP_READ, pagePosition.HighPart, pagePosition.LowPart, pageSize);
+			// map page
+			// copy to buffer
+			// increment buffer
+			// decrement length
+			// increment position
+		}
+		//else
+		{
+			// queue up read request to background thread
+			// wait for signal
+			continue;
+		}
+	}
+	return 0;
+}