vendor/kyua/0.13-a685f91vendor/kyua

1 files changed, 223 insertions, 0 deletions

diff --git a/cli/config.cpp b/cli/config.cpp
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+// Copyright 2011 The Kyua Authors.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+//   notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above copyright
+//   notice, this list of conditions and the following disclaimer in the
+//   documentation and/or other materials provided with the distribution.
+// * Neither the name of Google Inc. nor the names of its contributors
+//   may be used to endorse or promote products derived from this software
+//   without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "cli/config.hpp"
+
+#include "cli/common.hpp"
+#include "engine/config.hpp"
+#include "engine/exceptions.hpp"
+#include "utils/cmdline/options.hpp"
+#include "utils/cmdline/parser.ipp"
+#include "utils/config/tree.ipp"
+#include "utils/format/macros.hpp"
+#include "utils/fs/exceptions.hpp"
+#include "utils/fs/operations.hpp"
+#include "utils/fs/path.hpp"
+#include "utils/env.hpp"
+#include "utils/logging/macros.hpp"
+#include "utils/optional.ipp"
+
+namespace cmdline = utils::cmdline;
+namespace config = utils::config;
+namespace fs = utils::fs;
+
+using utils::optional;
+
+
+namespace {
+
+
+/// Basename of the configuration file.
+static const char* config_basename = "kyua.conf";
+
+
+/// Magic string to disable loading of configuration files.
+static const char* none_config = "none";
+
+
+/// Textual description of the default configuration files.
+///
+/// This is just an auxiliary string required to define the option below, which
+/// requires a pointer to a static C string.
+///
+/// \todo If the user overrides the KYUA_CONFDIR environment variable, we don't
+/// reflect this fact here.  We don't want to query the variable during program
+/// initialization due to the side-effects it may have.  Therefore, fixing this
+/// is tricky as it may require a whole rethink of this module.
+static const std::string config_lookup_names =
+    (fs::path("~/.kyua") / config_basename).str() + " or " +
+    (fs::path(KYUA_CONFDIR) / config_basename).str();
+
+
+/// Loads the configuration file for this session, if any.
+///
+/// This is a helper function that does not apply user-specified overrides.  See
+/// the documentation for cli::load_config() for more details.
+///
+/// \param cmdline The parsed command line.
+///
+/// \return The loaded configuration file, or the configuration defaults if the
+/// loading is disabled.
+///
+/// \throw engine::error If the parsing of the configuration file fails.
+///     TODO(jmmv): I'm not sure if this is the raised exception.  And even if
+///     it is, we should make it more accurate.
+config::tree
+load_config_file(const cmdline::parsed_cmdline& cmdline)
+{
+    // TODO(jmmv): We should really be able to use cmdline.has_option here to
+    // detect whether the option was provided or not instead of checking against
+    // the default value.
+    const fs::path filename = cmdline.get_option< cmdline::path_option >(
+        cli::config_option.long_name());
+    if (filename.str() == none_config) {
+        LD("Configuration loading disabled; using defaults");
+        return engine::default_config();
+    } else if (filename.str() != cli::config_option.default_value())
+        return engine::load_config(filename);
+
+    const optional< fs::path > home = utils::get_home();
+    if (home) {
+        const fs::path path = home.get() / ".kyua" / config_basename;
+        try {
+            if (fs::exists(path))
+                return engine::load_config(path);
+        } catch (const fs::error& e) {
+            // Fall through.  If we fail to load the user-specific configuration
+            // file because it cannot be openend, we try to load the system-wide
+            // one.
+            LW(F("Failed to load user-specific configuration file '%s': %s") %
+               path % e.what());
+        }
+    }
+
+    const fs::path confdir(utils::getenv_with_default(
+        "KYUA_CONFDIR", KYUA_CONFDIR));
+
+    const fs::path path = confdir / config_basename;
+    if (fs::exists(path)) {
+        return engine::load_config(path);
+    } else {
+        return engine::default_config();
+    }
+}
+
+
+/// Loads the configuration file for this session, if any.
+///
+/// This is a helper function for cli::load_config() that attempts to load the
+/// configuration unconditionally.
+///
+/// \param cmdline The parsed command line.
+///
+/// \return The loaded configuration file data.
+///
+/// \throw engine::error If the parsing of the configuration file fails.
+static config::tree
+load_required_config(const cmdline::parsed_cmdline& cmdline)
+{
+    config::tree user_config = load_config_file(cmdline);
+
+    if (cmdline.has_option(cli::variable_option.long_name())) {
+        typedef std::pair< std::string, std::string > override_pair;
+
+        const std::vector< override_pair >& overrides =
+            cmdline.get_multi_option< cmdline::property_option >(
+                cli::variable_option.long_name());
+
+        for (std::vector< override_pair >::const_iterator
+                 iter = overrides.begin(); iter != overrides.end(); iter++) {
+            try {
+                user_config.set_string((*iter).first, (*iter).second);
+            } catch (const config::error& e) {
+                // TODO(jmmv): Raising this type from here is obviously the
+                // wrong thing to do.
+                throw engine::error(e.what());
+            }
+        }
+    }
+
+    return user_config;
+}
+
+
+}  // anonymous namespace
+
+
+/// Standard definition of the option to specify a configuration file.
+///
+/// You must use load_config() to load a configuration file while honoring the
+/// value of this flag.
+const cmdline::path_option cli::config_option(
+    'c', "config",
+    (std::string("Path to the configuration file; '") + none_config +
+     "' to disable loading").c_str(),
+    "file", config_lookup_names.c_str());
+
+
+/// Standard definition of the option to specify a configuration variable.
+const cmdline::property_option cli::variable_option(
+    'v', "variable",
+    "Overrides a particular configuration variable",
+    "K=V");
+
+
+/// Loads the configuration file for this session, if any.
+///
+/// The algorithm implemented here is as follows:
+/// 1) If ~/.kyua/kyua.conf exists, load it.
+/// 2) Otherwise, if sysconfdir/kyua.conf exists, load it.
+/// 3) Otherwise, use the built-in settings.
+/// 4) Lastly, apply any user-provided overrides.
+///
+/// \param cmdline The parsed command line.
+/// \param required Whether the loading of the configuration file must succeed.
+///     Some commands should run regardless, and therefore we need to set this
+///     to false for those commands.
+///
+/// \return The loaded configuration file data.  If required was set to false,
+/// this might be the default configuration data if the requested file could not
+/// be properly loaded.
+///
+/// \throw engine::error If the parsing of the configuration file fails.
+config::tree
+cli::load_config(const cmdline::parsed_cmdline& cmdline,
+                 const bool required)
+{
+    try {
+        return load_required_config(cmdline);
+    } catch (const engine::error& e) {
+        if (required) {
+            throw;
+        } else {
+            LW(F("Ignoring failure to load configuration because the requested "
+                 "command should not fail: %s") % e.what());
+            return engine::default_config();
+        }
+    }
+}