file share support (#328)

this change adds a serve command to the zen CLI. This can be used to establish links to a set of files which may be served to clients via the project store interface:

```cmd> zen serve Lyra/WindowsClient d:\temp_share\StagedBuilds\WindowsClient```

with the appropriate changes in UE you may then start an instance of the runtime and have it load all files via the remote file connection:

```
Lyra\Binaries\LyraClient.exe ../../../Lyra/Lyra.uproject -pak -basedir=D:\temp_share\StagedBuilds\WindowsClient/Lyra/Binaries/Win64 -Mount=Lyra/WindowsClient
```

1 files changed, 36 insertions, 4 deletions

diff --git a/src/zen/zen.cpp b/src/zen/zen.cpp
index 464b2817c..a2ab31254 100644
--- a/src/zen/zen.cpp
+++ b/src/zen/zen.cpp
@@ -14,6 +14,7 @@
 #include "cmds/projectstore.h"
 #include "cmds/rpcreplay.h"
 #include "cmds/scrub.h"
+#include "cmds/serve.h"
 #include "cmds/status.h"
 #include "cmds/top.h"
 #include "cmds/up.h"
@@ -207,6 +208,7 @@ main(int argc, char** argv)
 	RpcStartRecordingCommand RpcStartRecordingCmd;
 	RpcStopRecordingCommand	 RpcStopRecordingCmd;
 	ScrubCommand			 ScrubCmd;
+	ServeCommand			 ServeCmd;
 	SnapshotOplogCommand	 SnapshotOplogCmd;
 	StatusCommand			 StatusCmd;
 	TopCommand				 TopCmd;
@@ -238,6 +240,7 @@ main(int argc, char** argv)
 		{"oplog-create",		&CreateOplogCmd,		"Create a project oplog"},
 		{"oplog-export",		&ExportOplogCmd,		"Export project store oplog"},
 		{"oplog-import",		&ImportOplogCmd,		"Import project store oplog"},
+		{"oplog-snapshot",		&SnapshotOplogCmd,		"Snapshot project store oplog"},
 		{"print",				&PrintCmd,				"Print compact binary object"},
 		{"printpackage",		&PrintPkgCmd,			"Print compact binary package"},
 		{"project-create",		&CreateProjectCmd,		"Create a project"},
@@ -250,7 +253,7 @@ main(int argc, char** argv)
 		{"rpc-record-start",	&RpcStartRecordingCmd,	"Replays a previously recorded session of rpc requests"},
 		{"rpc-record-stop",		&RpcStopRecordingCmd,	"Starts recording of cache rpc requests on a host"},
 		{"scrub",				&ScrubCmd,				"Scrub zen storage (verify data integrity)"},
-		{"oplog-snapshot",		&SnapshotOplogCmd,		"Snapshot project store oplog"},
+		{"serve",				&ServeCmd,				"Serve files from a directory"},
 		{"status",				&StatusCmd,				"Show zen status"},
 		{"top",					&TopCmd,				"Monitor zen server activity"},
 		{"up",					&UpCmd,					"Bring zen server up"},
@@ -437,20 +440,24 @@ main(int argc, char** argv)
 }
 
 std::string
-ZenCmdBase::ResolveTargetHostSpec(const std::string& InHostSpec)
+ZenCmdBase::ResolveTargetHostSpec(const std::string& InHostSpec, uint16_t& OutEffectivePort)
 {
 	if (InHostSpec.empty())
 	{
+		// If no host is specified then look to see if we have an instance
+		// running on this host and use that as the default to interact with
+
 		zen::ZenServerState Servers;
 
 		if (Servers.InitializeReadOnly())
 		{
-			std::string ResolvedSpec = InHostSpec;
+			std::string ResolvedSpec;
 
 			Servers.Snapshot([&](const zen::ZenServerState::ZenServerEntry& Entry) {
 				if (ResolvedSpec.empty())
 				{
-					ResolvedSpec = fmt::format("http://localhost:{}", Entry.EffectiveListenPort);
+					ResolvedSpec	 = fmt::format("http://localhost:{}", Entry.EffectiveListenPort);
+					OutEffectivePort = Entry.EffectiveListenPort;
 				}
 			});
 
@@ -458,5 +465,30 @@ ZenCmdBase::ResolveTargetHostSpec(const std::string& InHostSpec)
 		}
 	}
 
+	// Parse out port from the specification provided, to be consistent with
+	// the auto-discovery logic above.
+
+	std::string_view PortSpec(InHostSpec);
+	if (size_t PrefixIndex = PortSpec.find_last_of(":"); PrefixIndex != std::string_view::npos)
+	{
+		PortSpec.remove_prefix(PrefixIndex + 1);
+
+		std::optional<uint16_t> EffectivePort = zen::ParseInt<uint16_t>(PortSpec);
+
+		if (EffectivePort)
+		{
+			OutEffectivePort = EffectivePort.value();
+		}
+	}
+
+	// note: We should consider adding validation/normalization of the provided spec here
+
 	return InHostSpec;
 }
+
+std::string
+ZenCmdBase::ResolveTargetHostSpec(const std::string& InHostSpec)
+{
+	uint16_t Dummy = 0;
+	return ResolveTargetHostSpec(InHostSpec, /* out */ Dummy);
+}