pkgman: C++-ify the command handling

There's now a Command class that must be derived and registered with
a CommandManager, all simplified by a REGISTER_COMMAND macro. That gets
rid of the print_command_usage_and_exit() function copy for every
command, moves the short usage texts to the command implementations,
and avoids any repetition of the command name. When implementing a new
command only a new source file needs to be created, nothing else needs
to be touched.

src/bin/pkgman/Command.cpp

@@ -0,0 +1,107 @@
+/*
+ * Copyright 2013, Haiku, Inc. All Rights Reserved.
+ * Distributed under the terms of the MIT License.
+ *
+ * Authors:
+ *		Ingo Weinhold <[email protected]>
+ */
+
+
+#include "Command.h"
+
+#include <stdio.h>
+
+
+static int
+compare_commands_by_name(const Command* a, const Command* b)
+{
+	return a->Name().Compare(b->Name());
+}
+
+
+// #pragma mark - Command
+
+
+Command::Command(const BString& name, const BString& shortUsage,
+	const BString& longUsage)
+	:
+	fName(name),
+	fShortUsage(shortUsage),
+	fLongUsage(longUsage)
+{
+	fShortUsage.ReplaceAll("%command%", fName);
+	fLongUsage.ReplaceAll("%command%", fName);
+}
+
+
+Command::~Command()
+{
+}
+
+
+void
+Command::Init(const char* programName)
+{
+	fShortUsage.ReplaceAll("%program%", programName);
+	fLongUsage.ReplaceAll("%program%", programName);
+}
+
+
+void
+Command::PrintUsage(bool error) const
+{
+	fprintf(error ? stderr : stdout, "%s", fLongUsage.String());
+}
+
+
+void
+Command::PrintUsageAndExit(bool error) const
+{
+	PrintUsage(error);
+	exit(error ? 1 : 0);
+}
+
+
+// #pragma mark - CommandManager
+
+
+/*static*/ CommandManager*
+CommandManager::Default()
+{
+	static CommandManager* manager = new CommandManager;
+	return manager;
+}
+
+
+void
+CommandManager::RegisterCommand(Command* command)
+{
+	fCommands.AddItem(command);
+}
+
+
+void
+CommandManager::InitCommands(const char* programName)
+{
+	for (int32 i = 0; Command* command = fCommands.ItemAt(i); i++)
+		command->Init(programName);
+
+	fCommands.SortItems(&compare_commands_by_name);
+}
+
+
+void
+CommandManager::GetCommands(const char* prefix, CommandList& _commands)
+{
+	for (int32 i = 0; Command* command = fCommands.ItemAt(i); i++) {
+		if (command->Name().StartsWith(prefix))
+			_commands.AddItem(command);
+	}
+}
+
+
+CommandManager::CommandManager()
+	:
+	fCommands(20, true)
+{
+}

src/bin/pkgman/Command.h

@@ -0,0 +1,86 @@
+/*
+ * Copyright 2013, Haiku, Inc. All Rights Reserved.
+ * Distributed under the terms of the MIT License.
+ *
+ * Authors:
+ *		Ingo Weinhold <[email protected]>
+ */
+#ifndef COMMAND_H
+#define COMMAND_H
+
+
+#include <ObjectList.h>
+#include <String.h>
+
+
+class Command {
+public:
+								Command(const BString& name,
+									const BString& shortUsage,
+									const BString& longUsage);
+	virtual						~Command();
+
+			void				Init(const char* programName);
+
+			const BString&		Name() const		{ return fName; }
+			const BString&		ShortUsage() const	{ return fShortUsage; }
+			const BString&		LongUsage() const	{ return fName; }
+
+			void				PrintUsage(bool error) const;
+			void				PrintUsageAndExit(bool error) const;
+
+	virtual	int					Execute(int argc, const char* const* argv) = 0;
+
+private:
+			BString				fName;
+			BString				fShortUsage;
+			BString				fLongUsage;
+};
+
+
+typedef BObjectList<Command> CommandList;
+
+
+class CommandManager {
+public:
+	static	CommandManager*		Default();
+
+			void				RegisterCommand(Command* command);
+			void				InitCommands(const char* programName);
+
+			const CommandList&	Commands() const
+									{ return fCommands; }
+			void				GetCommands(const char* prefix,
+									CommandList& _commands);
+
+private:
+								CommandManager();
+
+private:
+			CommandList			fCommands;
+};
+
+
+template<typename CommandType>
+struct CommandRegistrar {
+	CommandRegistrar()
+	{
+		CommandManager::Default()->RegisterCommand(new CommandType);
+	}
+};
+
+
+#define DEFINE_COMMAND(className, name, shortUsage, longUsage)	\
+	struct className : Command {								\
+		className()												\
+			:													\
+			Command(name, shortUsage, longUsage)				\
+		{														\
+		}														\
+																\
+		virtual int Execute(int argc, const char* const* argv);	\
+	};															\
+	static CommandRegistrar<className> sRegister##className;
+
+
+#endif	// COMMAND_H

src/bin/pkgman/Jamfile

@@ -3,6 +3,7 @@ SubDir HAIKU_TOP src bin pkgman ;
 UsePrivateHeaders shared support ;
 
 BinCommand pkgman :
+	Command.cpp
 	command_add_repo.cpp
 	command_drop_repo.cpp
 	command_list_repos.cpp

src/bin/pkgman/command_add_repo.cpp

@@ -16,6 +16,7 @@
 #include <package/RefreshRepositoryRequest.h>
 #include <package/PackageRoster.h>
 
+#include "Command.h"
 #include "DecisionProvider.h"
 #include "JobStateListener.h"
 #include "pkgman.h"
@@ -27,23 +28,21 @@ using namespace BPackageKit;
 // TODO: internationalization!
 
 
-static const char* kCommandUsage =
+static const char* const kShortUsage =
-	"Usage: %s add-repo <repo-URL> [<repo-URL> ...]\n"
+	"  %command% <repo-base-url>\n"
+	"    Adds the repository with the given <repo-base-URL>.\n";
+
+static const char* const kLongUsage =
+	"Usage: %program% %command% <repo-URL> [<repo-URL> ...]\n"
 	"Adds one or more repositories by downloading them from the given URL(s).\n"
-	"\n"
+	"\n";
-;
 
 
-static void
+DEFINE_COMMAND(AddRepoCommand, "add-repo", kShortUsage, kLongUsage)
-print_command_usage_and_exit(bool error)
-{
-    fprintf(error ? stderr : stdout, kCommandUsage, kProgramName);
-    exit(error ? 1 : 0);
-}
 
 
 int
-command_add_repo(int argc, const char* const* argv)
+AddRepoCommand::Execute(int argc, const char* const* argv)
 {
 	bool asUserRepository = false;
 
@@ -61,7 +60,7 @@ command_add_repo(int argc, const char* const* argv)
 
 		switch (c) {
 			case 'h':
-				print_command_usage_and_exit(false);
+				PrintUsageAndExit(false);
 				break;
 
 			case 'u':
@@ -69,14 +68,14 @@ command_add_repo(int argc, const char* const* argv)
 				break;
 
 			default:
-				print_command_usage_and_exit(true);
+				PrintUsageAndExit(true);
 				break;
 		}
 	}
 
 	// The remaining arguments are repo URLs, i. e. at least one more argument.
 	if (argc < optind + 1)
-		print_command_usage_and_exit(true);
+		PrintUsageAndExit(true);
 
 	const char* const* repoURLs = argv + optind;
 	int urlCount = argc - optind;

src/bin/pkgman/command_drop_repo.cpp

@@ -14,6 +14,7 @@
 #include <package/DropRepositoryRequest.h>
 #include <package/Context.h>
 
+#include "Command.h"
 #include "DecisionProvider.h"
 #include "JobStateListener.h"
 #include "pkgman.h"
@@ -25,23 +26,21 @@ using namespace BPackageKit;
 // TODO: internationalization!
 
 
-static const char* kCommandUsage =
+static const char* const kShortUsage =
-	"Usage: %s drop-repo <repo-name>\n"
+	"  %command% <repo-name>\n"
+	"    Drops the repository with the given <repo-name>.\n";
+
+static const char* const kLongUsage =
+	"Usage: %program% %command% <repo-name>\n"
 	"Drops (i.e. removes) the repository with the given name.\n"
-	"\n"
+	"\n";
-;
 
 
-static void
+DEFINE_COMMAND(DropRepoCommand, "drop-repo", kShortUsage, kLongUsage)
-print_command_usage_and_exit(bool error)
-{
-    fprintf(error ? stderr : stdout, kCommandUsage, kProgramName);
-    exit(error ? 1 : 0);
-}
 
 
 int
-command_drop_repo(int argc, const char* const* argv)
+DropRepoCommand::Execute(int argc, const char* const* argv)
 {
 	bool yesMode = false;
 
@@ -59,7 +58,7 @@ command_drop_repo(int argc, const char* const* argv)
 
 		switch (c) {
 			case 'h':
-				print_command_usage_and_exit(false);
+				PrintUsageAndExit(false);
 				break;
 
 			case 'y':
@@ -67,14 +66,14 @@ command_drop_repo(int argc, const char* const* argv)
 				break;
 
 			default:
-				print_command_usage_and_exit(true);
+				PrintUsageAndExit(true);
 				break;
 		}
 	}
 
 	// The remaining argument is a repo name, i. e. one more argument.
 	if (argc != optind + 1)
-		print_command_usage_and_exit(true);
+		PrintUsageAndExit(true);
 
 	const char* repoName = argv[optind];
 

src/bin/pkgman/command_list_repos.cpp

@@ -21,6 +21,7 @@
 #include <package/PackageRoster.h>
 #include <package/RepositoryInfo.h>
 
+#include "Command.h"
 #include "pkgman.h"
 
 
@@ -30,24 +31,22 @@
 using namespace BPackageKit;
 
 
-static const char* kCommandUsage =
+static const char* const kShortUsage =
+	"  %command%\n"
+	"    Lists all repositories.\n";
+
+static const char* const kLongUsage =
 	"Usage:\n"
-	"    %s list-repos [options]\n"
+	"    %program% %command% [options]\n"
 	"Lists all configured package repositories.\n"
-	"\n"
+	"\n";
-;
 
 
-static void
+DEFINE_COMMAND(ListReposCommand, "list-repos", kShortUsage, kLongUsage)
-print_command_usage_and_exit(bool error)
-{
-    fprintf(error ? stderr : stdout, kCommandUsage, kProgramName);
-    exit(error ? 1 : 0);
-}
 
 
 int
-command_list_repos(int argc, const char* const* argv)
+ListReposCommand::Execute(int argc, const char* const* argv)
 {
 	bool verbose = false;
 
@@ -65,7 +64,7 @@ command_list_repos(int argc, const char* const* argv)
 
 		switch (c) {
 			case 'h':
-				print_command_usage_and_exit(false);
+				PrintUsageAndExit(false);
 				break;
 
 			case 'v':
@@ -73,14 +72,14 @@ command_list_repos(int argc, const char* const* argv)
 				break;
 
 			default:
-				print_command_usage_and_exit(true);
+				PrintUsageAndExit(true);
 				break;
 		}
 	}
 
 	// No remaining arguments.
 	if (argc != optind)
-		print_command_usage_and_exit(true);
+		PrintUsageAndExit(true);
 
 	BStringList repositoryNames(20);
 	BPackageRoster roster;

src/bin/pkgman/command_refresh.cpp

@@ -15,6 +15,7 @@
 #include <package/RefreshRepositoryRequest.h>
 #include <package/PackageRoster.h>
 
+#include "Command.h"
 #include "DecisionProvider.h"
 #include "JobStateListener.h"
 #include "pkgman.h"
@@ -26,23 +27,22 @@ using namespace BPackageKit;
 // TODO: internationalization!
 
 
-static const char* kCommandUsage =
+static const char* const kShortUsage =
-	"Usage: %s refresh [<repo-name> ...]\n"
+	"  %command% [<repo-name> ...]\n"
+	"    Refreshes all or just the given repositories.\n";
+
+static const char* const kLongUsage =
+	"Usage: %program% %command% [<repo-name> ...]\n"
 	"Refreshes all or just the given repositories.\n"
-	"\n"
+	"\n";
-;
 
 
-static void
+DEFINE_COMMAND(RefreshCommand, "refresh", kShortUsage, kLongUsage)
-print_command_usage_and_exit(bool error)
+
-{
-    fprintf(error ? stderr : stdout, kCommandUsage, kProgramName);
-    exit(error ? 1 : 0);
-}
 
 
 int
-command_refresh(int argc, const char* const* argv)
+RefreshCommand::Execute(int argc, const char* const* argv)
 {
 	while (true) {
 		static struct option sLongOptions[] = {
@@ -57,11 +57,11 @@ command_refresh(int argc, const char* const* argv)
 
 		switch (c) {
 			case 'h':
-				print_command_usage_and_exit(false);
+				PrintUsageAndExit(false);
 				break;
 
 			default:
-				print_command_usage_and_exit(true);
+				PrintUsageAndExit(true);
 				break;
 		}
 	}

src/bin/pkgman/command_resolve_dependencies.cpp

@@ -20,6 +20,7 @@
 
 #include <AutoDeleter.h>
 
+#include "Command.h"
 #include "pkgman.h"
 #include "RepositoryBuilder.h"
 
@@ -30,8 +31,12 @@
 using namespace BPackageKit;
 
 
-static const char* kCommandUsage =
+static const char* const kShortUsage =
-	"Usage: %s resolve-dependencies <package> <repository> [ <priority> ] ...\n"
+	"  %command% <package> <repository> [ <priority> ] ...\n"
+	"    Resolves all packages a given package depends on.\n";
+
+static const char* const kLongUsage =
+	"Usage: %program% %command% <package> <repository> [ <priority> ] ...\n"
 	"Resolves and lists all packages a given package depends on. Fails, if\n"
 	"not all dependencies could be resolved.\n"
 	"\n"
@@ -46,16 +51,11 @@ static const char* kCommandUsage =
 	"  <priority>\n"
 	"    Can follow a <repository> to specify the priority of that\n"
 	"    repository. The default priority is 0.\n"
-	"\n"
+	"\n";
-;
 
 
-static void
+DEFINE_COMMAND(ResolveDependenciesCommand, "resolve-dependencies", kShortUsage,
-print_command_usage_and_exit(bool error)
+	kLongUsage)
-{
-    fprintf(error ? stderr : stdout, kCommandUsage, kProgramName);
-    exit(error ? 1 : 0);
-}
 
 
 static void
@@ -107,7 +107,7 @@ verify_result(const BSolverResult& result, BSolverPackage* specifiedPackage)
 
 
 int
-command_resolve_dependencies(int argc, const char* const* argv)
+ResolveDependenciesCommand::Execute(int argc, const char* const* argv)
 {
 	while (true) {
 		static struct option sLongOptions[] = {
@@ -122,11 +122,11 @@ command_resolve_dependencies(int argc, const char* const* argv)
 
 		switch (c) {
 			case 'h':
-				print_command_usage_and_exit(false);
+				PrintUsageAndExit(false);
 				break;
 
 			default:
-				print_command_usage_and_exit(true);
+				PrintUsageAndExit(true);
 				break;
 		}
 	}
@@ -134,7 +134,7 @@ command_resolve_dependencies(int argc, const char* const* argv)
 	// The remaining arguments are the package (info) file and the repository
 	// directories (at least one), optionally with priorities.
 	if (argc < optind + 2)
-		print_command_usage_and_exit(true);
+		PrintUsageAndExit(true);
 
 	const char* packagePath = argv[optind++];
 	int repositoryDirectoryCount = argc - optind;

src/bin/pkgman/command_search.cpp

@@ -19,6 +19,7 @@
 
 #include <AutoDeleter.h>
 
+#include "Command.h"
 #include "pkgman.h"
 #include "RepositoryBuilder.h"
 
@@ -34,8 +35,12 @@ using namespace BPackageKit;
 typedef std::map<BSolverPackage*, BString> PackagePathMap;
 
 
-static const char* kCommandUsage =
+static const char* const kShortUsage =
-	"Usage: %s search <search-string>\n"
+	"  %command% <search-string>\n"
+	"    Searches for packages matching <search-string>.\n";
+
+static const char* const kLongUsage =
+	"Usage: %program% %command% <search-string>\n"
 	"Searches for packages matching <search-string>.\n"
 	"\n"
 	"Options:\n"
@@ -43,16 +48,10 @@ static const char* kCommandUsage =
 	"    Only find installed packages.\n"
 	"  -u, --uninstalled-only\n"
 	"    Only find not installed packages.\n"
-	"\n"
+	"\n";
-;
 
 
-static void
+DEFINE_COMMAND(SearchCommand, "search", kShortUsage, kLongUsage)
-print_command_usage_and_exit(bool error)
-{
-    fprintf(error ? stderr : stdout, kCommandUsage, kProgramName);
-    exit(error ? 1 : 0);
-}
 
 
 static int
@@ -68,7 +67,7 @@ get_terminal_width()
 
 
 int
-command_search(int argc, const char* const* argv)
+SearchCommand::Execute(int argc, const char* const* argv)
 {
 	bool installedOnly = false;
 	bool uninstalledOnly = false;
@@ -88,7 +87,7 @@ command_search(int argc, const char* const* argv)
 
 		switch (c) {
 			case 'h':
-				print_command_usage_and_exit(false);
+				PrintUsageAndExit(false);
 				break;
 
 			case 'i':
@@ -102,14 +101,14 @@ command_search(int argc, const char* const* argv)
 				break;
 
 			default:
-				print_command_usage_and_exit(true);
+				PrintUsageAndExit(true);
 				break;
 		}
 	}
 
 	// The remaining argument is the search string.
 	if (argc != optind + 1)
-		print_command_usage_and_exit(true);
+		PrintUsageAndExit(true);
 
 	const char* searchString = argv[optind++];
 

src/bin/pkgman/pkgman.cpp

@@ -11,34 +11,19 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "Command.h"
+
 
 extern const char* __progname;
 const char* kProgramName = __progname;
 
 
-static const char* kUsage =
+static const char* const kUsage =
 	"Usage: %s <command> <command args>\n"
-	"Creates, inspects, or extracts a Haiku package.\n"
+	"Manages packages and package repository.\n"
 	"\n"
 	"Commands:\n"
-	"  add-repo <repo-base-url>\n"
+	"%s"
-	"    Adds the repository with the given <repo-base-URL>.\n"
-	"\n"
-	"  drop-repo <repo-name>\n"
-	"    Drops the repository with the given <repo-name>.\n"
-	"\n"
-	"  list-repos\n"
-	"    Lists all repositories.\n"
-	"\n"
-	"  refresh [<repo-name> ...]\n"
-	"    Refreshes all or just the given repositories.\n"
-	"\n"
-	"  resolve-dependencies <package> <repository> [ <priority> ] ...\n"
-	"    Resolves all packages a given package depends on.\n"
-	"\n"
-	"  search <search-string>\n"
-	"    Searches for packages matching <search-string>.\n"
-	"\n"
 	"Common Options:\n"
 	"  -h, --help   - Print this usage info.\n"
 ;
@@ -47,7 +32,14 @@ static const char* kUsage =
 void
 print_usage_and_exit(bool error)
 {
-    fprintf(error ? stderr : stdout, kUsage, kProgramName);
+	BString commandsUsage;
+	const CommandList& commands = CommandManager::Default()->Commands();
+	for (int32 i = 0; Command* command = commands.ItemAt(i); i++)
+		commandsUsage << command->ShortUsage() << '\n';
+
+    fprintf(error ? stderr : stdout, kUsage, kProgramName,
+    	commandsUsage.String());
+
     exit(error ? 1 : 0);
 }
 
@@ -55,33 +47,19 @@ print_usage_and_exit(bool error)
 int
 main(int argc, const char* const* argv)
 {
+	CommandManager::Default()->InitCommands(kProgramName);
+
 	if (argc < 2)
 		print_usage_and_exit(true);
 
 	const char* command = argv[1];
-	if (strncmp(command, "add-r", 5) == 0)
-		return command_add_repo(argc - 1, argv + 1);
-
-	if (strncmp(command, "drop-r", 6) == 0)
-		return command_drop_repo(argc - 1, argv + 1);
-
-	if (strncmp(command, "list-r", 6) == 0)
-		return command_list_repos(argc - 1, argv + 1);
-
-	if (strncmp(command, "refr", 4) == 0)
-		return command_refresh(argc - 1, argv + 1);
-
-	if (strcmp(command, "resolve-dependencies") == 0)
-		return command_resolve_dependencies(argc - 1, argv + 1);
-
-	if (strcmp(command, "search") == 0)
-		return command_search(argc - 1, argv + 1);
-
 	if (strcmp(command, "help") == 0)
 		print_usage_and_exit(false);
-	else
+
+	CommandList commands;
+	CommandManager::Default()->GetCommands(command, commands);
+	if (commands.CountItems() != 1)
 		print_usage_and_exit(true);
 
-	// never gets here
+	return commands.ItemAt(0)->Execute(argc - 1, argv + 1);
-	return 0;
 }

src/bin/pkgman/pkgman.h

@@ -34,12 +34,6 @@ do {																\
 
 
 void	print_usage_and_exit(bool error);
-int		command_add_repo(int argc, const char* const* argv);
-int		command_drop_repo(int argc, const char* const* argv);
-int		command_list_repos(int argc, const char* const* argv);
-int		command_refresh(int argc, const char* const* argv);
-int		command_resolve_dependencies(int argc, const char* const* argv);  
-int		command_search(int argc, const char* const* argv);  
 
 
 #endif	// PKGMAN_H