fix Issue #528 - fetch doesn't work for recently updated package

Revert "store metadata cache on disk"

This reverts commit 161aad0.

We only ask the package suppliers for metadata when upgrading or
searching a specific package version. In particular building an already
fetched package does not ask the package suppliers (only the package
manager responsible for locally installed packages).

In all cases where we get data from a package supplier we want to get
the latest available information. Therefor it doesn't make sense to
cache any metadata from the package suppliers on disk.

Not sure whether we still need the in memory metadata cache (e.g. for
multiple queries during dependency resolution).

source/dub/commandline.d

@@ -207,10 +207,7 @@ int runDubCommandLine(string[] args)
 	}
 
 	// execute the command
-	int rc;
-	try {
-		rc = cmd.execute(dub, remaining_args, app_args);
-	}
+	try return cmd.execute(dub, remaining_args, app_args);
 	catch (UsageException e) {
 		logError("%s", e.msg);
 		logDebug("Full exception: %s", e.toString().sanitize);
@@ -222,10 +219,6 @@ int runDubCommandLine(string[] args)
 		logDebug("Full exception: %s", e.toString().sanitize);
 		return 2;
 	}
-
-	if (!cmd.skipDubInitialization)
-		dub.shutdown();
-	return rc;
 }
 
 struct CommonOptions {
@@ -413,7 +406,7 @@ class InitCommand : Command {
 
 		void depCallback(ref PackageRecipe p, ref PackageFormat fmt) {
 			if (m_nonInteractive) return;
-			
+
 			while (true) {
 				string rawfmt = input("Package recipe format (sdl/json)", fmt.to!string);
 				if (!rawfmt.length) break;
@@ -1482,7 +1475,6 @@ class CleanCachesCommand : Command {
 
 	override int execute(Dub dub, string[] free_args, string[] app_args)
 	{
-		dub.cleanCaches();
 		return 0;
 	}
 }
@@ -1630,7 +1622,7 @@ class DustmiteCommand : PackageBuildCommand {
 			auto testcmd = appender!string();
 			testcmd.formattedWrite("%s dustmite --vquiet --test-package=%s --build=%s --config=%s",
 				thisExePath, prj.name, m_buildType, m_buildConfig);
-			
+
 			if (m_compilerName.length) testcmd.formattedWrite(" \"--compiler=%s\"", m_compilerName);
 			if (m_arch.length) testcmd.formattedWrite(" --arch=%s", m_arch);
 			if (m_compilerStatusCode != int.min) testcmd.formattedWrite(" --compiler-status=%s", m_compilerStatusCode);

source/dub/dub.d

@@ -117,10 +117,6 @@ class Dub {
 		if (skip_registry < SkipRegistry.standard)
 			ps ~= defaultPackageSuppliers();
 
-		auto cacheDir = m_userDubPath ~ "cache/";
-		foreach (p; ps)
-			p.cacheOp(cacheDir, CacheOp.load);
-
 		m_packageSuppliers = ps;
 		m_packageManager = new PackageManager(m_userDubPath, m_systemDubPath);
 		updatePackageSearchPath();
@@ -153,22 +149,6 @@ class Dub {
 		m_systemConfig = jsonFromFile(m_systemDubPath ~ "settings.json", true);
 	}
 
-	/// Perform cleanup and persist caches to disk
-	void shutdown()
-	{
-		auto cacheDir = m_userDubPath ~ "cache/";
-		foreach (p; m_packageSuppliers)
-			p.cacheOp(cacheDir, CacheOp.store);
-	}
-
-	/// cleans all metadata caches
-	void cleanCaches()
-	{
-		auto cacheDir = m_userDubPath ~ "cache/";
-		foreach (p; m_packageSuppliers)
-			p.cacheOp(cacheDir, CacheOp.clean);
-	}
-
 	@property void dryRun(bool v) { m_dryRun = v; }
 
 	/** Returns the root path (usually the current working directory).
@@ -796,7 +776,7 @@ class Dub {
 			logInfo("Package format is already %s.", destination_file_ext);
 			return;
 		}
-		
+
 		writePackageRecipe(srcfile[0 .. $-1] ~ ("dub."~destination_file_ext), m_project.rootPackage.info);
 		removeFile(srcfile);
 	}

source/dub/packagesupplier.d

@@ -39,20 +39,10 @@ interface PackageSupplier {
 	/// returns the metadata for the package
 	Json getPackageDescription(string packageId, Dependency dep, bool pre_release);
 
-	/// perform cache operation
-	void cacheOp(Path cacheDir, CacheOp op);
-
 	static struct SearchResult { string name, description, version_; }
 	SearchResult[] searchPackages(string query);
 }
 
-/// operations on package supplier cache
-enum CacheOp {
-	load,
-	store,
-	clean,
-}
-
 class FileSystemPackageSupplier : PackageSupplier {
 	private {
 		Path m_path;
@@ -92,9 +82,6 @@ class FileSystemPackageSupplier : PackageSupplier {
 		return jsonFromZip(filename, "dub.json");
 	}
 
-	void cacheOp(Path cacheDir, CacheOp op) {
-	}
-
 	SearchResult[] searchPackages(string query) {
 		return null;
 	}
@@ -122,10 +109,9 @@ class RegistryPackageSupplier : PackageSupplier {
 		struct CacheEntry { Json data; SysTime cacheTime; }
 		CacheEntry[string] m_metadataCache;
 		Duration m_maxCacheTime;
-		bool m_metadataCacheDirty;
 	}
 
-	this(URL registry)
+ 	this(URL registry)
 	{
 		m_registryUrl = registry;
 		m_maxCacheTime = 24.hours();
@@ -160,52 +146,13 @@ class RegistryPackageSupplier : PackageSupplier {
 		return getBestPackage(packageId, dep, pre_release);
 	}
 
-	void cacheOp(Path cacheDir, CacheOp op)
-	{
-		auto path = cacheDir ~ cacheFileName;
-		final switch (op)
-		{
-		case CacheOp.store:
-			if (!m_metadataCacheDirty) return;
-			if (!cacheDir.existsFile())
-				mkdirRecurse(cacheDir.toNativeString());
-			// TODO: method is slow due to Json escaping
-			atomicWriteJsonFile(path, m_metadataCache.serializeToJson());
-			break;
-
-		case CacheOp.load:
-			if (!path.existsFile()) return;
-			try deserializeJson(m_metadataCache, jsonFromFile(path));
-			catch (Exception e) {
-				import std.encoding;
-				logWarn("Error loading package cache file %s: %s", path.toNativeString(), e.msg);
-				logDebug("Full error: %s", e.toString().sanitize());
-			}
-			break;
-
-		case CacheOp.clean:
-			if (path.existsFile()) removeFile(path);
-			m_metadataCache.destroy();
-			break;
-		}
-		m_metadataCacheDirty = false;
-	}
-
-	private @property string cacheFileName()
-	{
-		import std.digest.md;
-		auto hash = m_registryUrl.toString.md5Of();
-		return m_registryUrl.host ~ hash[0 .. $/2].toHexString().idup ~ ".json";
-	}
-
 	private Json getMetadata(string packageId)
 	{
 		auto now = Clock.currTime(UTC());
 		if (auto pentry = packageId in m_metadataCache) {
 			if (pentry.cacheTime + m_maxCacheTime > now)
 				return pentry.data;
 			m_metadataCache.remove(packageId);
-			m_metadataCacheDirty = true;
 		}
 
 		auto url = m_registryUrl ~ Path(PackagesPath ~ "/" ~ packageId ~ ".json");
@@ -219,7 +166,6 @@ class RegistryPackageSupplier : PackageSupplier {
 		foreach (ref v; json["versions"])
 			v.remove("readme");
 		m_metadataCache[packageId] = CacheEntry(json, now);
-		m_metadataCacheDirty = true;
 		return json;
 	}