From 815db0727c6374a2fcfb6e2fb6795b1e4ed953a3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=B6nke=20Ludwig?= <sludwig@rejectedsoftware.com>
Date: Mon, 20 Nov 2017 22:23:30 +0100
Subject: [PATCH] Change all invalid handle values to ~0 and improve
 FileChange.

FileChange now has the full path of a file split into the base path (as specified when creating the watcher), the sub directory, and the file name. This allows to work with less dynamic memory allocations internally.
---
 source/eventcore/driver.d                  | 25 ++++++++++++++--------
 source/eventcore/drivers/winapi/watchers.d |  8 ++++---
 2 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/source/eventcore/driver.d b/source/eventcore/driver.d
index 8b4f07c..a411bd1 100644
--- a/source/eventcore/driver.d
+++ b/source/eventcore/driver.d
@@ -652,14 +652,21 @@ struct FileChange {
 	/// The type of change
 	FileChangeKind kind;
 
-	/// Directory containing the changed file
-	string directory;
+	/// The root directory of the watcher
+	string baseDirectory;
 
-	/// Determines if the changed entity is a file or a directory.
-	bool isDirectory;
+	/// Subdirectory containing the changed file
+	string directory;
 
 	/// Name of the changed file
 	const(char)[] name;
+
+	/** Determines if the changed entity is a file or a directory.
+
+		Note that depending on the platform this may not be accurate for
+		`FileChangeKind.removed`.
+	*/
+	bool isDirectory;
 }
 
 struct Handle(string NAME, T, T invalid_value = T.init) {
@@ -695,8 +702,8 @@ alias StreamListenSocketFD = Handle!("streamListen", SocketFD);
 alias DatagramSocketFD = Handle!("datagramSocket", SocketFD);
 alias FileFD = Handle!("file", FD);
 alias EventID = Handle!("event", FD);
-alias TimerID = Handle!("timer", size_t);
-alias WatcherID = Handle!("watcher", size_t);
-alias EventWaitID = Handle!("eventWait", size_t);
-alias SignalListenID = Handle!("signal", size_t);
-alias DNSLookupID = Handle!("dns", size_t);
+alias TimerID = Handle!("timer", size_t, size_t.max);
+alias WatcherID = Handle!("watcher", size_t, size_t.max);
+alias EventWaitID = Handle!("eventWait", size_t, size_t.max);
+alias SignalListenID = Handle!("signal", size_t, size_t.max);
+alias DNSLookupID = Handle!("dns", size_t, size_t.max);
diff --git a/source/eventcore/drivers/winapi/watchers.d b/source/eventcore/drivers/winapi/watchers.d
index 1911cd7..f7fc0a4 100644
--- a/source/eventcore/drivers/winapi/watchers.d
+++ b/source/eventcore/drivers/winapi/watchers.d
@@ -78,6 +78,7 @@ final class WinAPIEventDriverWatchers : EventDriverWatchers {
 	void onIOCompleted(DWORD dwError, DWORD cbTransferred, OVERLAPPED* overlapped)
 	{
 		import std.conv : to;
+		import std.path : dirName, baseName;
 
 		if (dwError != 0) {
 			// FIXME: this must be propagated to the caller
@@ -114,9 +115,10 @@ final class WinAPIEventDriverWatchers : EventDriverWatchers {
 				case 0x4: ch.kind = FileChangeKind.removed; break;
 				case 0x5: ch.kind = FileChangeKind.added; break;
 			}
-			ch.directory = slot.directory;
-			ch.isDirectory = false; // FIXME: is this right?
-			ch.name = () @trusted { scope (failure) assert(false); return to!string(fni.FileName[0 .. fni.FileNameLength/2]); } ();
+			ch.baseDirectory = slot.directory;
+			auto path = () @trusted { scope (failure) assert(false); return to!string(fni.FileName[0 .. fni.FileNameLength/2]); } ();
+			ch.directory = dirName(path);
+			ch.name = baseName(path);
 			slot.callback(id, ch);
 			if (fni.NextEntryOffset == 0) break;
 			result = result[fni.NextEntryOffset .. $];