[cache_restore] --debug-override-metadata-version

A flag that deliberately causes the wrong metadata version to be
written.  Useful for testing the kernel module.

caching/cache_restore.cc

@@ -5,12 +5,14 @@
 #include "caching/xml_format.h"
 #include "persistent-data/file_utils.h"
 
+#include <boost/lexical_cast.hpp>
 #include <fstream>
 #include <getopt.h>
 #include <iostream>
 #include <libgen.h>
 #include <string>
 
+using namespace boost;
 using namespace caching;
 using namespace persistent_data;
 using namespace std;
@@ -18,14 +20,31 @@ using namespace std;
 //----------------------------------------------------------------
 
 namespace {
-	int restore(string const &xml_file, string const &dev) {
+	struct flags {
+		flags()
+			: metadata_version(1),
+			  override_metadata_version(false) {
+		}
+
+		optional<string> input;
+		optional<string> output;
+		uint32_t metadata_version;
+		bool override_metadata_version;
+	};
+
+	int restore(flags const &fs) {
 		try {
-			block_manager<>::ptr bm = open_bm(dev, block_io<>::READ_WRITE);
+			block_manager<>::ptr bm = open_bm(*fs.output, block_io<>::READ_WRITE);
 			metadata::ptr md(new metadata(bm, metadata::CREATE));
 			emitter::ptr restorer = create_restore_emitter(md);
 
-			check_file_exists(xml_file);
-			ifstream in(xml_file.c_str(), ifstream::in);
+			if (fs.override_metadata_version) {
+				cerr << "overriding" << endl;
+				md->sb_.version = fs.metadata_version;
+			}
+
+			check_file_exists(*fs.input);
+			ifstream in(fs.input->c_str(), ifstream::in);
 			parse_xml(in, restorer);
 
 		} catch (std::exception &e) {
@@ -42,17 +61,21 @@ namespace {
 		    << "  {-h|--help}" << endl
 		    << "  {-i|--input} <input xml file>" << endl
 		    << "  {-o|--output} <output device or file>" << endl
-		    << "  {-V|--version}" << endl;
+		    << "  {-V|--version}" << endl
+		    << endl
+		    << "  {--debug-override-metadata-version} <integer>" << endl;
+
 	}
 }
 
 int main(int argc, char **argv)
 {
 	int c;
-	string input, output;
+	flags fs;
 	char const *prog_name = basename(argv[0]);
 	char const *short_opts = "hi:o:V";
 	option const long_opts[] = {
+		{ "debug-override-metadata-version", required_argument, NULL, 0 },
 		{ "help", no_argument, NULL, 'h'},
 		{ "input", required_argument, NULL, 'i' },
 		{ "output", required_argument, NULL, 'o'},
@@ -62,16 +85,21 @@ int main(int argc, char **argv)
 
 	while ((c = getopt_long(argc, argv, short_opts, long_opts, NULL)) != -1) {
 		switch(c) {
+		case 0:
+			fs.metadata_version = lexical_cast<uint32_t>(optarg);
+			fs.override_metadata_version = true;
+			break;
+
 		case 'h':
 			usage(cout, prog_name);
 			return 0;
 
 		case 'i':
-			input = optarg;
+			fs.input = optional<string>(string(optarg));
 			break;
 
 		case 'o':
-			output = optarg;
+			fs.output = optional<string>(string(optarg));
 			break;
 
 		case 'V':
@@ -89,20 +117,19 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
-        if (input.empty()) {
+        if (!fs.input) {
 		cerr << "No input file provided." << endl << endl;
 		usage(cerr, prog_name);
 		return 1;
 	}
 
-	if (output.empty()) {
+	if (!fs.output) {
 		cerr << "No output file provided." << endl << endl;
 		usage(cerr, prog_name);
 		return 1;
 	}
 
-	return restore(input, output);
+	return restore(fs);
 }
 
 //----------------------------------------------------------------
-

caching/superblock.cc

@@ -55,7 +55,7 @@ namespace {
 
 	uint32_t const SUPERBLOCK_MAGIC = 06142003;
 	uint32_t const VERSION_BEGIN = 1;
-	uint32_t const VERSION_END = 3;
+	uint32_t const VERSION_END = 2;
 }
 
 //----------------------------------------------------------------

features/cache_check.feature

@@ -86,3 +86,9 @@ Feature: cache_check
     When I run `cache_check metadata.bin`
     Then it should pass
 
+  Scenario: Invalid metadata version causes a fail
+    Given a small xml file
+    And input file
+    And I run cache_restore with -i metadata.xml -o input --debug-override-metadata-version 12345
+    When I run `cache_check input`
+    Then it should fail

features/cache_restore.feature

@@ -9,7 +9,8 @@ Feature: thin_restore
 
   Scenario: print help (-h)
     When I run cache_restore with -h
-    Then it should pass with:
+    Then it should pass
+    And the output should contain exactly:
 
     """
     Usage: cache_restore [options]
@@ -18,11 +19,15 @@ Feature: thin_restore
       {-i|--input} <input xml file>
       {-o|--output} <output device or file>
       {-V|--version}
+
+      {--debug-override-metadata-version} <integer>
+
     """
 
   Scenario: print help (--help)
     When I run cache_restore with -h
-    Then it should pass with:
+    Then it should pass
+    And the output should contain exactly:
 
     """
     Usage: cache_restore [options]
@@ -31,6 +36,9 @@ Feature: thin_restore
       {-i|--input} <input xml file>
       {-o|--output} <output device or file>
       {-V|--version}
+
+      {--debug-override-metadata-version} <integer>
+
     """
 
   Scenario: missing input file
@@ -53,9 +61,14 @@ Feature: thin_restore
     No output file provided.
     """
 
-  @announce
   Scenario: successfully restores a valid xml file
     Given a small xml file
     And an empty dev file
     When I run cache_restore with -i metadata.xml -o metadata.bin
     Then it should pass
+
+  Scenario: accepts --debug-override-metadata-version
+    Given a small xml file
+    And an empty dev file
+    When I run cache_restore with -i metadata.xml -o metadata.bin --debug-override-metadata-version 10298
+    Then it should pass