added heapdir directive to allow for configuration of where QFork memory mapped file lives

msvs/setups/documentation/redis.windows.conf

@@ -289,7 +289,9 @@ slave-priority 100
 # be shared with a child process. 
 #
 # *** There must be disk space available for this file in order for Redis 
-# to launch. ***
+# to launch. *** The default configuration places this file in the local 
+# appdata directory. If you wish to move this file to another local disk,
+# use the heapdir flag as described below.
 #
 # The maxheap flag controls the maximum size of this memory mapped file,
 # as well as the total usable space for the Redis heap. Running Redis
@@ -314,6 +316,17 @@ slave-priority 100
 #  
 # maxheap <bytes>
 
+# The heap memory mapped file must reside on a local path for heap sharing 
+# between processes to work. A UNC path will not suffice here. For maximum 
+# performance this should be located on the fastest local drive available.
+# This value defaults to the local application data folder(e.g.,
+# "%USERPROFILE%\AppData\Local"). Since this file can be very large, you
+# may wish to place this on a drive other than the one the operating system  
+# is installed on.
+#
+# Note that you must specify a directory here, not a file name.
+# heapdir <directory path(absolute or relative)>
+
 # Don't use more memory than the specified amount of bytes.
 # When the memory limit is reached Redis will try to remove keys
 # accordingly to the eviction policy selected (see maxmemmory-policy).

src/Win32_Interop/Win32_CommandLine.cpp

@@ -353,6 +353,7 @@ static RedisParamterMapper g_redisArgMap =
     // QFork flags
     { cQFork,                           &fp2 },    // qfork [QForkConrolMemoryMap handle] [parent process id]
     { cMaxHeap,                         &fp1 },    // maxheap [number]
+    { cHeapDir,                         &fp1 },    // heapdir [path]
 
     // service commands
     { cServiceName,                     &fp1 },    // service-name [name]

src/Win32_Interop/Win32_CommandLine.h

@@ -51,6 +51,7 @@ const string cSyslogIdent= "syslog-ident";
 const string cLogfile = "logfile";
 const string cInclude = "include";
 const string cDir = "dir";
+const string cHeapDir = "heapdir";
 
 const string cMaxHeap = "maxheap";
 const string cMaxMemory = "maxmemory";

src/Win32_Interop/Win32_QFork.cpp

@@ -25,6 +25,8 @@
 #include <stdio.h>
 #include <wchar.h>
 #include <Psapi.h>
+#include <ShlObj.h>
+#include <Shlwapi.h>
 
 #define QFORK_MAIN_IMPL
 #include "Win32_QFork.h"
@@ -332,16 +334,41 @@ BOOL QForkSlaveInit(HANDLE QForkConrolMemoryMapHandle, DWORD ParentProcessID) {
     return FALSE;
 }
 
+string g_MMFDir;
 string GetWorkingDirectory() {
-    string workingDir = ".\\";
-    if (g_argMap.find(cDir) != g_argMap.end()) {
-        workingDir = g_argMap[cDir][0][0];
-    }
-    std::replace(workingDir.begin(), workingDir.end(), '/', '\\');
-    if (workingDir.at(workingDir.length() - 1) != '\\') {
-        workingDir = workingDir.append("\\");
+    if (g_MMFDir.length() == 0) {
+        char defaultDir[_MAX_PATH];
+        HRESULT hr;
+        if (S_OK != (hr = SHGetFolderPathA(NULL, CSIDL_LOCAL_APPDATA, NULL, SHGFP_TYPE_CURRENT, defaultDir))) {
+            throw std::system_error(hr,system_category(),"SHGetFolderPathA failed");
+        }
+
+        string workingDir = defaultDir;
+        if (g_argMap.find(cHeapDir) != g_argMap.end()) {
+            workingDir = g_argMap[cHeapDir][0][0];
+            std::replace(workingDir.begin(), workingDir.end(), '/', '\\');
+
+            if (PathIsRelativeA(workingDir.c_str())) {
+                char cwd[MAX_PATH];
+                if (0 == ::GetCurrentDirectoryA(MAX_PATH, cwd)) {
+                    throw std::system_error(GetLastError(), system_category(), "GetCurrentDirectoryA failed");
+                }
+                char fullPath[_MAX_PATH];
+                if (NULL == PathCombineA(fullPath, cwd, workingDir.c_str())) {
+                    throw std::system_error(GetLastError(), system_category(), "PathCombineA failed");
+                }
+                workingDir = fullPath;
+            }
+        }
+
+        if (workingDir.at(workingDir.length() - 1) != '\\') {
+            workingDir = workingDir.append("\\");
+        }
+
+        g_MMFDir = workingDir;
     }
-    return workingDir;
+
+    return g_MMFDir;
 }
 
 BOOL QForkMasterInit( __int64 maxheapBytes ) {

src/config.c

@@ -522,7 +522,9 @@ void loadServerConfigFromString(char *config) {
 #ifdef _WIN32
 		} else if (!strcasecmp(argv[0],"maxheap")) {
 			// ignore. This is taken care of in the qfork code.
-		} else if (!strcasecmp(argv[0],"service-name")) {
+        } else if (!strcasecmp(argv[0], "heapdir")) {
+            // ignore. This is taken care of in the qfork code.
+        } else if (!strcasecmp(argv[0], "service-name")) {
 			// ignore. This is taken care of in the win32_service code.
 #endif
 		} else {