Implement migrate-long-name

sources/commands.cpp

@@ -818,7 +818,7 @@ class MountCommand : public CommandBase
                 ERROR_LOG(
                     "Config file %s does not exist. Perhaps you forget to run `create` command "
                     "first?",
-                    single_pass_holder_.get_real_config_path_for_reading().c_str());
+                    single_pass_holder_.get_real_config_path_for_reading());
                 return 19;
             }
             throw;
@@ -1034,13 +1034,10 @@ class InfoCommand : public CommandBase
     int execute() override
     {
         auto real_config_path = single_pass_holder_.get_real_config_path_for_reading();
-        auto params
-            = decrypt(OSService::get_default()
-                          .open_file_stream(
-                              single_pass_holder_.get_real_config_path_for_reading(), O_RDONLY, 0)
-                          ->as_string(),
-                      {single_pass_holder_.password.data(), single_pass_holder_.password.size()},
-                      maybe_open_key_stream(single_pass_holder_.keyfile.getValue()).get());
+        auto params = decrypt(
+            OSService::get_default().open_file_stream(real_config_path, O_RDONLY, 0)->as_string(),
+            {single_pass_holder_.password.data(), single_pass_holder_.password.size()},
+            maybe_open_key_stream(single_pass_holder_.keyfile.getValue()).get());
         if (!unmask.getValue())
         {
             if (params.has_lite_format_params())
@@ -1070,6 +1067,83 @@ class InfoCommand : public CommandBase
     }
 };
 
+class MigrateLongNameCommand : public CommandBase
+{
+private:
+    SinglePasswordHolder single_pass_holder_{cmdline()};
+    Argon2idArgsHolder argon2{cmdline()};
+
+    static constexpr size_t kDefaultLongNameThreshold = 128;
+
+public:
+    const char* long_name() const noexcept override { return "migrate-long-name"; }
+    char short_name() const noexcept override { return 0; }
+    const char* help_message() const noexcept override
+    {
+        return "Migrate a lite format repository without long name support.";
+    }
+    void parse_cmdline(int argc, const char* const* argv) override
+    {
+        CommandBase::parse_cmdline(argc, argv);
+        single_pass_holder_.get_password(false);
+    }
+
+    int execute() override
+    {
+        auto real_config_path = single_pass_holder_.get_real_config_path_for_reading();
+        auto params = decrypt(
+            OSService::get_default().open_file_stream(real_config_path, O_RDONLY, 0)->as_string(),
+            {single_pass_holder_.password.data(), single_pass_holder_.password.size()},
+            maybe_open_key_stream(single_pass_holder_.keyfile.getValue()).get());
+        if (!params.has_lite_format_params())
+        {
+            throw_runtime_error("This command is only available for lite format repositories.");
+        }
+        if (params.lite_format_params().long_name_threshold() > 0)
+        {
+            WARN_LOG("Already supports long name.");
+            return 0;
+        }
+        size_t max_filename_length = 0;
+        OSService::get_default().recursive_traverse(
+            single_pass_holder_.data_dir.getValue(),
+            [&](const std::string& dir, const std::string& name, int type)
+            {
+                if (type == S_IFLNK)
+                {
+                    throw_runtime_error("Cannot migrate when symbolic links are present.");
+                }
+                max_filename_length = std::max(max_filename_length, name.size());
+            });
+        size_t threshold;
+        if (max_filename_length < (kDefaultLongNameThreshold + 16) * 8 / 5)
+        {
+            threshold = kDefaultLongNameThreshold;
+        }
+        else
+        {
+            threshold = max_filename_length * 5 / 8 - 16;
+        }
+        params.mutable_lite_format_params()->set_long_name_threshold(threshold);
+        auto encrypted_data
+            = encrypt(params,
+                      argon2.to_params(),
+                      {single_pass_holder_.password.data(), single_pass_holder_.password.size()},
+                      maybe_open_key_stream(single_pass_holder_.keyfile.getValue()).get())
+                  .SerializeAsString();
+        auto tmp_path = absl::StrCat(real_config_path, ".tmp");
+        auto stream = OSService::get_default().open_file_stream(
+            tmp_path, O_WRONLY | O_CREAT | O_EXCL, 0644);
+        DEFER(if (has_uncaught_exceptions()) {
+            OSService::get_default().remove_file_nothrow(tmp_path);
+        });
+        stream->write(encrypted_data.data(), 0, encrypted_data.size());
+        stream.reset();
+        OSService::get_default().rename(tmp_path, real_config_path);
+        return 0;
+    }
+};
+
 class DocCommand : public CommandBase
 {
 private:
@@ -1212,6 +1286,7 @@ int commands_main(int argc, const char* const* argv)
                                                make_unique<ChangePasswordCommand>(),
                                                make_unique<VersionCommand>(),
                                                make_unique<InfoCommand>(),
+                                               make_unique<MigrateLongNameCommand>(),
                                                make_unique<DocCommand>()};
 
         const char* const program_name = argv[0];

sources/common_platform.cpp

@@ -76,14 +76,11 @@ void OSService::recursive_traverse(const std::string& dir,
     {
         if (name == "." || name == "..")
             continue;
+        callback(dir, name, S_IFMT & st.st_mode);
         if ((S_IFMT & st.st_mode) == S_IFDIR)
         {
             recursive_traverse(StrCat(dir, "/", name), callback);
         }
-        else
-        {
-            callback(dir, name);
-        }
     }
 }
 

sources/myutils.cpp

@@ -19,38 +19,40 @@ static void find_ids_helper(const std::string& current_dir,
 {
     id_type id;
     std::string hex(id_type::size() * 2, 0);
-    OSService::recursive_traverse_callback callback
-        = [&id, &result, &hex](std::string_view dir, std::string_view name) -> bool
+    auto callback = [&id, &result, &hex](std::string_view dir, std::string_view name, int type)
     {
-        if (name == "." || name == "..")
-            return true;
-        if (absl::EndsWithIgnoreCase(name, ".meta"))
+        if (type != S_IFREG)
         {
-            std::string total_name
-                = absl::StrCat(dir, "/", name.substr(0, name.size() - strlen(".meta")));
-            hex.assign(hex.size(), 0);
-            ptrdiff_t i = hex.size() - 1, j = total_name.size() - 1;
-            while (i >= 0 && j >= 0)
+            return;
+        }
+        if (!absl::EndsWithIgnoreCase(name, ".meta"))
+        {
+            return;
+        }
+
+        std::string total_name
+            = absl::StrCat(dir, "/", name.substr(0, name.size() - strlen(".meta")));
+        hex.assign(hex.size(), 0);
+        ptrdiff_t i = hex.size() - 1, j = total_name.size() - 1;
+        while (i >= 0 && j >= 0)
+        {
+            char namechar = total_name[j];
+            if ((namechar >= '0' && namechar <= '9') || (namechar >= 'a' && namechar <= 'f'))
+            {
+                hex[i] = namechar;
+                --i;
+            }
+            else if (namechar != '/' && namechar != '\\')
             {
-                char namechar = total_name[j];
-                if ((namechar >= '0' && namechar <= '9') || (namechar >= 'a' && namechar <= 'f'))
-                {
-                    hex[i] = namechar;
-                    --i;
-                }
-                else if (namechar != '/' && namechar != '\\')
-                {
-                    throw_runtime_error(absl::StrFormat(
-                        "File \"%s\" has extension .meta, but not a valid securefs "
-                        "meta filename. Please cleanup the underlying storage first.",
-                        total_name));
-                }
-                --j;
+                throw_runtime_error(
+                    absl::StrFormat("File \"%s\" has extension .meta, but not a valid securefs "
+                                    "meta filename. Please cleanup the underlying storage first.",
+                                    total_name));
             }
-            parse_hex(hex, id.data(), id.size());
-            result.insert(id);
+            --j;
         }
-        return true;
+        parse_hex(hex, id.data(), id.size());
+        result.insert(id);
     };
 
     OSService::get_default().recursive_traverse(current_dir, callback);

sources/platform.h

@@ -5,6 +5,7 @@
 #include "streams.h"
 
 #include <absl/base/thread_annotations.h>
+#include <absl/functional/function_ref.h>
 #include <absl/synchronization/mutex.h>
 #include <uni_algo/conv.h>
 
@@ -205,7 +206,8 @@ class OSService
     ssize_t readlink(const std::string& path, char* output, size_t size) const;
     void symlink(const std::string& source, const std::string& dest) const;
 
-    typedef std::function<void(const std::string&, const std::string&)> recursive_traverse_callback;
+    using recursive_traverse_callback
+        = absl::FunctionRef<void(const std::string&, const std::string&, int)>;
     void recursive_traverse(const std::string& dir,
                             const recursive_traverse_callback& callback) const;