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kdb.c
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kdb.c
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/**
* @file
*
* @brief Low level functions for access the Key Database.
*
* @copyright BSD License (see LICENSE.md or https://www.libelektra.org)
*/
#ifdef HAVE_KDBCONFIG_H
#include "kdbconfig.h"
#endif
#if DEBUG && defined(HAVE_STDIO_H)
#include <stdio.h>
#endif
#include <kdbassert.h>
#ifdef HAVE_LOCALE_H
#include <locale.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STDARG_H
#include <stdarg.h>
#endif
#ifdef HAVE_CTYPE_H
#include <ctype.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_STDIO_H
#include <stdio.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#include <kdbinternal.h>
#define KDB_GET_PHASE_POST_STORAGE_SPEC (KDB_GET_PHASE_POST_STORAGE "/spec")
#define KDB_GET_PHASE_POST_STORAGE_NONSPEC (KDB_GET_PHASE_POST_STORAGE "/nonspec")
/**
* @defgroup kdb KDB
* @brief General methods to access the Key database.
*
* To use them:
* @code
* #include <kdb.h>
* @endcode
*
* The kdb*() methods are used to access the storage, to get and set
* @link keyset KeySets@endlink.
*
* Parameters common for all these functions are:
*
* - *handle*, as returned by kdbOpen(), need to be passed to every call
* - *parentKey* is used for every call to add warnings and set an
* error. For kdbGet() / kdbSet() it is used to specify which keys
* should be retrieved/stored.
*
* @note The parentKey is an obligation for you, but only an hint for KDB.
* KDB does not remember anything
* about the configuration. You need to pass the same configuration
* back to kdbSet(), otherwise parts of the configuration get
* lost. Only keys below the parentKey are subject for change, the rest
* must be left untouched.
*
* KDB uses different backend implementations that know the details
* about how to access the storage.
* One backend consists of multiple plugins.
* See @link plugin writing a new plugin @endlink for information
* about how to write a plugin.
* Backends are state-less regarding the configuration (because of that
* you must pass back the whole configuration for every backend), but
* have a state for:
*
* - a two phase-commit
* - a conflict detection (error C02000) and
* - optimizations that avoid redoing already done operations.
*
* @image html state.png "State"
* @image latex state.png "State"
*
* As we see in the figure, kdbOpen() can be called arbitrarily often in any
* number of threads.
*
* For every handle you got from kdbOpen(), for every parentKey with a
* different name, *only* the shown state transitions
* are valid. From a freshly opened KDB, only kdbGet() and kdbClose()
* are allowed, because otherwise conflicts (error C02000) would not be detected.
*
* Once kdbGet() was called (for a specific handle+parentKey),
* any number of kdbGet() and kdbSet() can be
* used with this handle respective parentKey, unless kdbSet() had
* a conflict (error C02000) with another application.
* Every affair with KDB needs to be finished with kdbClose().
*
* The name of the parentKey in kdbOpen() and kdbClose() does not matter.
*
* In the usual case we just have one parentKey and one handle. In
* these cases we just have to remember to use kdbGet() before
* kdbSet():
*
* @include kdbintro.c
*
* To output warnings, you can use following code:
*
* @snippet tests.c warnings
*
* To output the error, you can use following code:
*
* @snippet tests.c error
*
* @{
*/
static bool closeBackends (KeySet * backends, Key * errorKey)
{
for (elektraCursor i = 0; i < ksGetSize (backends); i++)
{
Key * backendKey = ksAtCursor (backends, i);
const BackendData * backendData = keyValue (backendKey);
for (elektraCursor p = 0; p < ksGetSize (backendData->plugins); p++)
{
Plugin * plugin = *(Plugin **) keyValue (ksAtCursor (backendData->plugins, p));
if (elektraPluginClose (plugin, errorKey) == ELEKTRA_PLUGIN_STATUS_ERROR)
{
return false;
}
}
ksDel (backendData->plugins);
ksDel (backendData->keys);
ksDel (backendData->definition);
}
ksDel (backends);
return true;
}
/**
* @brief Takes the first key and cuts off this common part
* for all other keys, instead name will be prepended
*
* @return a new allocated keyset with keys in user namespace.
*
* The first key is removed in the resulting keyset.
*/
KeySet * ksRenameKeys (KeySet * config, const char * name)
{
Key * root;
Key * cur;
ssize_t rootSize = 0;
ksRewind (config);
root = ksNext (config);
rootSize = keyGetNameSize (root);
keyDel (ksLookup (config, root, KDB_O_POP));
KeySet * newConfig = ksNew (ksGetSize (config), KS_END);
if (rootSize == -1) return newConfig;
while ((cur = ksPop (config)) != 0)
{
Key * dupKey = keyDup (cur, KEY_CP_ALL);
keySetName (dupKey, name);
keyAddName (dupKey, keyName (cur) + rootSize - 1);
ksAppendKey (newConfig, dupKey);
keyDel (cur);
}
return newConfig;
}
static void clearErrorAndWarnings (Key * key)
{
Key * cutRoot = keyNew ("meta:/error", KEY_END);
ksDel (ksCut (keyMeta (key), cutRoot));
keySetName (cutRoot, "meta:/warnings");
ksDel (ksCut (keyMeta (key), cutRoot));
keyDel (cutRoot);
}
/**
* Checks whether the same instance of the list plugin is mounted in the global (maxonce) positions:
*
* pregetstorage, procgetstorage, postgetstorage, postgetcleanup,
* presetstorage, presetcleanup, precommit, postcommit,
* prerollback and postrollback
*
* @param handle the KDB handle to check
* @param errorKey used for error reporting
*
* @retval 1 if list is mounted everywhere
* @retval 0 otherwise
*/
static int ensureListPluginMountedEverywhere (KDB * handle, Key * errorKey)
{
GlobalpluginPositions expectedPositions[] = { PREGETSTORAGE,
PROCGETSTORAGE,
POSTGETSTORAGE,
POSTGETCLEANUP,
PRESETSTORAGE,
PRESETCLEANUP,
PRECOMMIT,
POSTCOMMIT,
PREROLLBACK,
POSTROLLBACK,
-1 };
Plugin * list = handle->globalPlugins[expectedPositions[0]][MAXONCE];
if (list == NULL || elektraStrCmp (list->name, "list") != 0)
{
ELEKTRA_SET_INSTALLATION_ERRORF (errorKey, "list plugin not mounted at position %s/maxonce",
GlobalpluginPositionsStr[expectedPositions[0]]);
return 0;
}
for (int i = 1; expectedPositions[i] > 0; ++i)
{
Plugin * plugin = handle->globalPlugins[expectedPositions[i]][MAXONCE];
if (plugin != list)
{
// must always be the same instance
ELEKTRA_SET_INSTALLATION_ERRORF (errorKey, "list plugin not mounted at position %s/maxonce",
GlobalpluginPositionsStr[expectedPositions[i]]);
return 0;
}
}
return 1;
}
/**
* Handles the system:/elektra/contract/globalkeyset part of kdbOpen() contracts
*
* NOTE: @p contract will be modified
*
* @see kdbOpen()
*/
static void ensureContractGlobalKs (KDB * handle, KeySet * contract)
{
Key * globalKsContractRoot = keyNew ("system:/elektra/contract/globalkeyset", KEY_END);
Key * globalKsRoot = keyNew ("system:/elektra", KEY_END);
KeySet * globalKs = ksCut (contract, globalKsContractRoot);
ksRename (globalKs, globalKsContractRoot, globalKsRoot);
ksAppend (handle->global, globalKs);
ksDel (globalKs);
keyDel (globalKsContractRoot);
keyDel (globalKsRoot);
}
/**
* Handles the system:/elektra/contract/mountglobal part of kdbOpen() contracts
*
* NOTE: @p contract will be modified
*
* @see kdbOpen()
*/
static int ensureContractMountGlobal (KDB * handle, KeySet * contract, Key * parentKey)
{
if (!ensureListPluginMountedEverywhere (handle, parentKey))
{
return -1;
}
Plugin * listPlugin = handle->globalPlugins[PREGETSTORAGE][MAXONCE];
typedef int (*mountPluginFun) (Plugin *, const char *, KeySet *, Key *);
mountPluginFun listAddPlugin = (mountPluginFun) elektraPluginGetFunction (listPlugin, "mountplugin");
typedef int (*unmountPluginFun) (Plugin *, const char *, Key *);
unmountPluginFun listRemovePlugin = (unmountPluginFun) elektraPluginGetFunction (listPlugin, "unmountplugin");
Key * mountContractRoot = keyNew ("system:/elektra/contract/mountglobal", KEY_END);
Key * pluginConfigRoot = keyNew ("user:/", KEY_END);
for (elektraCursor it = ksFindHierarchy (contract, mountContractRoot, NULL); it < ksGetSize (contract); it++)
{
Key * cur = ksAtCursor (contract, it);
if (keyIsDirectlyBelow (mountContractRoot, cur) == 1)
{
const char * pluginName = keyBaseName (cur);
KeySet * pluginConfig = ksCut (contract, cur);
// increment ref count, because cur is part of pluginConfig and
// we hold a reference to cur that is still needed (via pluginName)
keyIncRef (cur);
ksRename (pluginConfig, cur, pluginConfigRoot);
int ret = listRemovePlugin (listPlugin, pluginName, parentKey);
if (ret != ELEKTRA_PLUGIN_STATUS_ERROR)
{
ret = listAddPlugin (listPlugin, pluginName, pluginConfig, parentKey);
}
// we ned to delete cur separately, because it was ksCut() from contract
// we also need to decrement the ref count, because it was incremented above
keyDecRef (cur);
keyDel (cur);
if (ret == ELEKTRA_PLUGIN_STATUS_ERROR)
{
ELEKTRA_SET_INSTALLATION_ERRORF (
parentKey, "The plugin '%s' couldn't be mounted globally (via the 'list' plugin).", pluginName);
return -1;
}
// adjust cursor, because we removed the current key
--it;
}
}
keyDel (mountContractRoot);
keyDel (pluginConfigRoot);
return 0;
}
/**
* Handles the @p contract argument of kdbOpen().
*
* @see kdbOpen()
*/
static bool ensureContract (KDB * handle, const KeySet * contract, Key * parentKey)
{
// TODO (kodebach): tests
// deep dup, so modifications to the keys in contract after kdbOpen() cannot modify the contract
KeySet * dup = ksDeepDup (contract);
ensureContractGlobalKs (handle, dup);
int ret = ensureContractMountGlobal (handle, dup, parentKey);
ksDel (dup);
return ret == 0;
}
/**
* @internal
*
* Helper for kdbOpen(). Creates empty KDB instance.
*
* @see kdbOpen()
*/
static KDB * kdbNew (Key * errorKey)
{
KDB * handle = elektraCalloc (sizeof (struct _KDB));
handle->modules = ksNew (0, KS_END);
if (elektraModulesInit (handle->modules, errorKey) == -1)
{
// TODO (kodebach) [Q]: shouldn't we let elektraModulesInit set this error?
ELEKTRA_SET_INSTALLATION_ERROR (
errorKey, "Method 'elektraModulesInit' returned with -1. See other warning or error messages for concrete details");
ksDel (handle->modules);
elektraFree (handle);
return NULL;
}
handle->global =
ksNew (1, keyNew ("system:/elektra/kdb", KEY_BINARY, KEY_SIZE, sizeof (handle), KEY_VALUE, &handle, KEY_END), KS_END);
handle->backends = ksNew (0, KS_END);
return handle;
}
static void addMountpoint (KeySet * backends, Key * mountpoint, Plugin * backend, KeySet * plugins, KeySet * definition)
{
BackendData backendData = {
.backend = backend,
.keys = ksNew (0, KS_END),
.plugins = plugins,
.definition = definition,
.getSize = 0,
.initialized = false,
.keyNeedsSync = false,
};
keySetBinary (mountpoint, &backendData, sizeof (backendData));
ksAppendKey (backends, mountpoint);
}
static bool addElektraMountpoint (KeySet * backends, KeySet * modules, KeySet * global, Key * errorKey)
{
// TODO (kodebach): implement user:/elektra and dir:/elektra
// FIXME (kodebach): replace KDB_DEFAULT_STORAGE with separate KDB_BOOTSTRAP_STORAGE
Plugin * storage = elektraPluginOpen (KDB_DEFAULT_STORAGE, modules, ksNew (0, KS_END), errorKey);
if (storage == NULL)
{
ELEKTRA_SET_INSTALLATION_ERRORF (errorKey, "Could not open boostrap storage plugin ('%s'). See warnings for details.",
KDB_DEFAULT_STORAGE);
return false;
}
storage->global = global;
// TODO (kodebach) [Q]: support direct read-write to absolute path in backend plugin to avoid resolver in bootstrap?
Plugin * resolver = elektraPluginOpen (KDB_DEFAULT_RESOLVER, modules, ksNew (0, KS_END), errorKey);
if (resolver == NULL)
{
ELEKTRA_SET_INSTALLATION_ERRORF (errorKey, "Could not open boostrap resolver plugin ('%s'). See warnings for details.",
KDB_DEFAULT_RESOLVER);
elektraPluginClose (resolver, errorKey);
return false;
}
resolver->global = global;
Plugin * backend = elektraPluginOpen ("backend", modules, ksNew (0, KS_END), errorKey);
if (backend == NULL)
{
ELEKTRA_SET_INSTALLATION_ERROR (errorKey,
"Could not open system:/elektra backend during bootstrap. See other warnings for details");
elektraPluginClose (resolver, errorKey);
elektraPluginClose (storage, errorKey);
return false;
}
backend->global = global;
// clang-format off
KeySet * plugins =
ksNew (1,
keyNew ("system:/#0", KEY_BINARY, KEY_SIZE, sizeof (resolver), KEY_VALUE, &resolver, KEY_END),
keyNew ("system:/#1", KEY_BINARY, KEY_SIZE, sizeof (storage), KEY_VALUE, &storage, KEY_END),
KS_END);
KeySet * definition =
ksNew (3,
keyNew ("system:/path", KEY_VALUE, KDB_DB_INIT, KEY_END),
keyNew ("system:/positions/get/resolver", KEY_VALUE, "#0", KEY_END),
keyNew ("system:/positions/get/storage", KEY_VALUE, "#1", KEY_END),
keyNew ("system:/positions/set/resolver", KEY_VALUE, "#0", KEY_END),
keyNew ("system:/positions/set/storage", KEY_VALUE, "#1", KEY_END),
keyNew ("system:/positions/set/commit", KEY_VALUE, "#0", KEY_END),
keyNew ("system:/positions/set/rollback", KEY_VALUE, "#0", KEY_END),
KS_END);
// clang-format on
addMountpoint (backends, keyNew (KDB_SYSTEM_ELEKTRA, KEY_END), backend, plugins, definition);
return true;
}
static KeySet * elektraBoostrap (KDB * handle, Key * errorKey)
{
KeySet * elektraKs = ksNew (0, KS_END);
Key * bootstrapParent = keyNew (KDB_SYSTEM_ELEKTRA, KEY_END);
if (kdbGet (handle, elektraKs, bootstrapParent) == -1)
{
ELEKTRA_SET_INSTALLATION_ERROR (errorKey,
"Bootstrapping failed, please fix '" KDB_DB_SYSTEM "/" KDB_DB_INIT
"'. If the error persists, please report this bug at https://issues.libelektra.org.");
Key * warningsRoot = keyNew ("meta:/warnings", KEY_END);
ksAppend (keyMeta (errorKey), ksBelow (keyMeta (bootstrapParent), warningsRoot));
keyDel (warningsRoot);
elektraTriggerWarnings (keyString (keyGetMeta (bootstrapParent, "meta:/error/number")), errorKey,
keyString (keyGetMeta (bootstrapParent, "meta:/error/reason")));
ksDel (elektraKs);
keyDel (bootstrapParent);
return NULL;
}
keyDel (bootstrapParent);
return elektraKs;
}
static bool openPlugins (KeySet * plugins, const Key * pluginsRoot, KeySet * modules, KeySet * global, const KeySet * systemConfig,
Key * errorKey)
{
bool success = true;
for (elektraCursor i = 0; i < ksGetSize (plugins); i++)
{
Key * cur = ksAtCursor (plugins, i);
if (keyIsDirectlyBelow (pluginsRoot, cur) == 1)
{
Key * lookupHelper = keyDup (cur, KEY_CP_NAME);
keyAddBaseName (lookupHelper, "name");
Key * nameKey = ksLookup (plugins, lookupHelper, 0);
const char * pluginName = nameKey == NULL ? NULL : keyString (nameKey);
if (nameKey == NULL || strlen (pluginName) == 0)
{
ELEKTRA_ADD_INSTALLATION_WARNINGF (errorKey,
"The plugin definition at '%s' doesn't contain a plugin name. Please "
"set '%s/name' to a non-empty string value.",
keyName (cur), keyName (cur));
success = false;
keyDel (lookupHelper);
continue;
}
keySetBaseName (lookupHelper, "config");
KeySet * config = ksBelow (plugins, lookupHelper);
Key * configRoot = keyNew ("user:/", KEY_END);
ksRename (config, lookupHelper, configRoot);
keyDel (configRoot);
ksAppend (config, systemConfig);
keyDel (lookupHelper);
Plugin * plugin = elektraPluginOpen (pluginName, modules, config, errorKey);
if (plugin == NULL)
{
ELEKTRA_ADD_INSTALLATION_WARNINGF (
errorKey, "Could not open the plugin '%s' defined at '%s'. See other warnings for details.",
pluginName, keyName (cur));
success = false;
continue;
}
plugin->global = global;
// create Plugin * key ...
Key * pluginKey = keyDup (cur, KEY_CP_NAME);
keySetBinary (pluginKey, &plugin, sizeof (plugin));
// ... remove definition (includes cur) ...
ksDel (ksCut (plugins, cur));
// ... and replace Plugin * key
ksAppendKey (plugins, pluginKey);
}
else
{
ELEKTRA_ADD_INSTALLATION_WARNINGF (
errorKey,
"The key '%s' doesn't belong to a plugin definition. Keys below '%s' must be part of a plugin definition.",
keyName (cur), keyName (pluginsRoot));
success = false;
continue;
}
}
return success;
}
static KeySet * dupPluginSet (KeySet * plugins, Key * errorKey)
{
KeySet * dupPlugins = ksNew (ksGetSize (plugins), KS_END);
bool success = true;
for (elektraCursor i = 0; i < ksGetSize (plugins); i++)
{
Key * cur = ksAtCursor (plugins, i);
const Plugin * plugin = *(const Plugin **) keyValue (cur);
Plugin * dup = elektraPluginOpen (plugin->name, plugin->modules, ksDup (plugin->config), errorKey);
if (dup == NULL)
{
ELEKTRA_ADD_INSTALLATION_WARNINGF (
errorKey, "Could not open the plugin '%s' defined at '%s'. See other warnings for details.", plugin->name,
keyName (cur));
success = false;
continue;
}
dup->global = plugin->global;
Key * dupKey = keyDup (cur, KEY_CP_NAME);
keySetBinary (dupKey, &dup, sizeof (dup));
ksAppendKey (dupPlugins, dupKey);
}
if (!success)
{
ksDel (dupPlugins);
return NULL;
}
else
{
return dupPlugins;
}
}
static bool addDupMountpoint (KeySet * mountpoints, Key * mountpoint, Key * backendPluginKey, KeySet * plugins, KeySet * definition,
Key * errorKey)
{
KeySet * dupPlugins = dupPluginSet (plugins, errorKey);
if (dupPlugins == NULL)
{
keyDel (mountpoint);
return false;
}
Plugin * backendPlugin = *(Plugin **) keyValue (backendPluginKey);
addMountpoint (mountpoints, keyDup (mountpoint, KEY_CP_NAME), backendPlugin, dupPlugins, ksDup (definition));
return true;
}
static bool parseAndAddMountpoint (KeySet * mountpoints, KeySet * modules, KeySet * elektraKs, KeySet * global, Key * root, Key * errorKey)
{
// check that the base name is a key name
Key * mountpoint = keyNew (keyBaseName (root), KEY_END);
if (mountpoint == NULL)
{
ELEKTRA_ADD_INSTALLATION_WARNINGF (errorKey, "'%s' is not a valid key name, but is used for the mountpoint '%s'",
keyBaseName (root), keyName (root));
return false;
}
// FIXME (kodebach): reserve /elektra/... in every namespace
Key * elektraRoot = keyNew (KDB_SYSTEM_ELEKTRA, KEY_END);
if (keyIsBelowOrSame (elektraRoot, mountpoint) != 0)
{
ELEKTRA_ADD_INSTALLATION_WARNINGF (
errorKey,
"The mountpoint '%s' (defined at '%s') is not allowed. Everything below '" KDB_SYSTEM_ELEKTRA
"' is reserved for use by Elektra.",
keyBaseName (root), keyName (root));
return false;
}
// load mountpoint level config
Key * lookupHelper = keyDup (root, KEY_CP_NAME);
keyAddBaseName (lookupHelper, "config");
KeySet * systemConfig = ksBelow (elektraKs, lookupHelper);
Key * configRoot = keyNew ("system:/", KEY_END);
ksRename (systemConfig, lookupHelper, configRoot);
keyDel (configRoot);
// get the plugin list and remove the common prefix
keySetBaseName (lookupHelper, "plugins");
KeySet * plugins = ksBelow (elektraKs, lookupHelper);
// open all plugins (replaces key values with Plugin *)
if (!openPlugins (plugins, lookupHelper, modules, global, systemConfig, errorKey))
{
keyDel (mountpoint);
keyDel (lookupHelper);
ksDel (plugins);
ksDel (systemConfig);
return false;
}
// TODO (kodebach): read and process config/needs from contract
ksDel (systemConfig);
Key * pluginsRoot = keyNew ("system:/", KEY_END);
ksRename (plugins, lookupHelper, pluginsRoot);
keyDel (pluginsRoot);
// find backend plugin
Key * backendPluginKey = ksLookupByName (plugins, "system:/backend", 0);
if (backendPluginKey == NULL)
{
ELEKTRA_ADD_INSTALLATION_WARNINGF (errorKey, "The mountpoint '%s' defined in '%s' does not specify a backend plugin.",
keyName (mountpoint), keyName (root));
keyDel (mountpoint);
keyDel (lookupHelper);
ksDel (plugins);
return false;
}
// get definition section
keySetBaseName (lookupHelper, "definition");
KeySet * definition = ksBelow (elektraKs, lookupHelper);
Key * definitionRoot = keyNew ("system:/", KEY_END);
ksRename (definition, lookupHelper, definitionRoot);
keyDel (definitionRoot);
keyDel (lookupHelper);
// create mountpoint
if (keyGetNamespace (mountpoint) == KEY_NS_CASCADING)
{
keySetNamespace (mountpoint, KEY_NS_SYSTEM);
if (!addDupMountpoint (mountpoints, mountpoint, backendPluginKey, plugins, definition, errorKey))
{
return false;
}
keySetNamespace (mountpoint, KEY_NS_USER);
if (!addDupMountpoint (mountpoints, mountpoint, backendPluginKey, plugins, definition, errorKey))
{
return false;
}
keySetNamespace (mountpoint, KEY_NS_DIR);
if (!addDupMountpoint (mountpoints, mountpoint, backendPluginKey, plugins, definition, errorKey))
{
return false;
}
keySetNamespace (mountpoint, KEY_NS_PROC);
if (!addDupMountpoint (mountpoints, mountpoint, backendPluginKey, plugins, definition, errorKey))
{
return false;
}
keyDel (mountpoint);
}
else
{
Plugin * backendPlugin = *(Plugin **) keyValue (backendPluginKey);
addMountpoint (mountpoints, mountpoint, backendPlugin, plugins, definition);
}
return true;
}
// FIXME (kodebach): write tests
KeySet * elektraMountpointsParse (KeySet * elektraKs, KeySet * modules, KeySet * global, Key * errorKey)
{
KeySet * mountpoints = ksNew (0, KS_END);
Key * mountpointsRoot = keyNew (KDB_SYSTEM_ELEKTRA "/mountpoints", KEY_END);
bool error = false;
for (elektraCursor end, i = ksFindHierarchy (elektraKs, mountpointsRoot, &end); i < end;)
{
Key * cur = ksAtCursor (elektraKs, i);
if (keyIsDirectlyBelow (mountpointsRoot, cur) == 1)
{
if (!parseAndAddMountpoint (mountpoints, modules, elektraKs, global, cur, errorKey))
{
error = true;
}
// skip over the keys we just parsed
Key * lookup = keyDup (cur, KEY_CP_NAME);
ksFindHierarchy (elektraKs, lookup, &i);
keyDel (lookup);
}
else
{
ELEKTRA_ADD_INSTALLATION_WARNINGF (
errorKey,
"The key '%s' is below 'system:/elektra/mountpoints', but doesn't belong to a mountpoint configuration. To "
"define a mountpoint for the parent e.g. 'user:/mymountpoint' the key "
"'system:/elektra/user:\\/mymountpoint' must exist and be set to an arbitrary (possibly empty) value.",
keyName (cur));
++i;
}
}
if (error)
{
closeBackends (mountpoints, errorKey);
ELEKTRA_SET_INSTALLATION_ERROR (errorKey, "Some mountpoints couldn't be parsed. See warnings for details.");
return NULL;
}
return mountpoints;
}
static bool addRootMountpoint (KeySet * backends, elektraNamespace ns, KeySet * modules, KeySet * global, Key * errorKey)
{
Key * rootKey = keyNew ("/", KEY_END);
keySetNamespace (rootKey, ns);
if (ksLookup (backends, rootKey, 0) != NULL)
{
// already present
keyDel (rootKey);
return true;
}
Plugin * defaultResolver = elektraPluginOpen (KDB_RESOLVER, modules, ksNew (0, KS_END), errorKey);
if (defaultResolver == NULL)
{
ELEKTRA_SET_INSTALLATION_ERROR (errorKey, "Could not open default resolver plugin. See warnings for details.");
return false;
}
defaultResolver->global = global;
Plugin * defaultStorage = elektraPluginOpen (KDB_STORAGE, modules, ksNew (0, KS_END), errorKey);
if (defaultStorage == NULL)
{
ELEKTRA_SET_INSTALLATION_ERROR (errorKey, "Could not open default storage plugin. See warnings for details.");
elektraPluginClose (defaultResolver, errorKey);
return false;
}
defaultStorage->global = global;
// clang-format off
KeySet * rootPlugins =
ksNew (2,
keyNew ("system:/resolver", KEY_BINARY, KEY_SIZE, sizeof (defaultResolver), KEY_VALUE, &defaultResolver, KEY_END),
keyNew ("system:/storage", KEY_BINARY, KEY_SIZE, sizeof (defaultStorage), KEY_VALUE, &defaultStorage, KEY_END),
KS_END);
KeySet * rootDefinition =
ksNew (7,
keyNew ("system:/path", KEY_VALUE, KDB_DB_FILE, KEY_END),
keyNew ("system:/positions/get/resolver", KEY_VALUE, "resolver", KEY_END),
keyNew ("system:/positions/get/storage", KEY_VALUE, "storage", KEY_END),
keyNew ("system:/positions/set/resolver", KEY_VALUE, "resolver", KEY_END),
keyNew ("system:/positions/set/storage", KEY_VALUE, "storage", KEY_END),
keyNew ("system:/positions/set/commit", KEY_VALUE, "resolver", KEY_END),
keyNew ("system:/positions/set/rollback", KEY_VALUE, "resolver", KEY_END),
KS_END);
// clang-format on
Plugin * root = elektraPluginOpen ("backend", modules, ksNew (0, KS_END), errorKey);
if (root == NULL)
{
ELEKTRA_SET_INSTALLATION_ERROR (errorKey, "Could not open default backend. See warnings for details.");
ksDel (rootPlugins);
ksDel (rootDefinition);
elektraPluginClose (defaultResolver, errorKey);
elektraPluginClose (defaultStorage, errorKey);
return false;
}
root->global = global;
addMountpoint (backends, rootKey, root, rootPlugins, rootDefinition);
return true;
}
static bool addModulesMountpoint (KDB * handle, Key * mountpoint, Key * errorKey)
{
Plugin * modules = elektraPluginOpen ("modules", handle->modules, ksNew (0, KS_END), errorKey);
if (modules == NULL)
{
ELEKTRA_SET_INSTALLATION_ERRORF (
errorKey, "Could not open 'modules' plugin for mountpoint 'system:/elektra/modules/%s'. See warnings for details.",
keyBaseName (mountpoint));
return false;
}
Plugin * plugin = elektraPluginOpen (keyBaseName (mountpoint), handle->modules,
ksNew (1, keyNew ("system:/module", KEY_END), KS_END), errorKey);
if (plugin == NULL)
{
ELEKTRA_SET_INSTALLATION_ERRORF (
errorKey, "Could not open '%s' plugin for mountpoint 'system:/elektra/modules/%s'. See warnings for details.",
keyBaseName (mountpoint), keyBaseName (mountpoint));
return false;
}
modules->global = handle->global;
addMountpoint (handle->backends, mountpoint, modules, ksNew (0, KS_END),
ksNew (1, keyNew ("system:/plugin", KEY_BINARY, KEY_SIZE, sizeof (plugin), KEY_VALUE, &plugin, KEY_END), KS_END));
return true;
}
static bool addHardcodedMountpoints (KDB * handle, Key * errorKey)
{
if (!addElektraMountpoint (handle->backends, handle->modules, handle->global, errorKey))
{
return false;
}
if (!addRootMountpoint (handle->backends, KEY_NS_SPEC, handle->modules, handle->global, errorKey))
{
return false;
}
if (!addRootMountpoint (handle->backends, KEY_NS_SYSTEM, handle->modules, handle->global, errorKey))
{
return false;
}
if (!addRootMountpoint (handle->backends, KEY_NS_USER, handle->modules, handle->global, errorKey))
{
return false;
}
if (!addRootMountpoint (handle->backends, KEY_NS_DIR, handle->modules, handle->global, errorKey))
{
return false;
}
if (!addRootMountpoint (handle->backends, KEY_NS_PROC, handle->modules, handle->global, errorKey))
{
return false;
}
Key * modulesRoot = keyNew (KDB_SYSTEM_ELEKTRA "/modules", KEY_END);
Plugin * modules = elektraPluginOpen ("modules", handle->modules, ksNew (0, KS_END), errorKey);
if (modules == NULL)
{
ELEKTRA_SET_INSTALLATION_ERROR (errorKey, "Could not open system:/elektra/modules backend. See warnings for details.");
return false;
}
modules->global = handle->global;
addMountpoint (handle->backends, modulesRoot, modules, ksNew (0, KS_END), ksNew (0, KS_END));
for (elektraCursor i = 0; i < ksGetSize (handle->modules); i++)
{
Key * cur = ksAtCursor (handle->modules, i);
if (keyIsDirectlyBelow (modulesRoot, cur) != 1)
{
continue;
}
if (!addModulesMountpoint (handle, keyDup (cur, KEY_CP_NAME), errorKey))
{
return false;
}
}
Plugin * version = elektraPluginOpen ("version", handle->modules, ksNew (0, KS_END), errorKey);
if (version == NULL)
{
ELEKTRA_SET_INSTALLATION_ERROR (errorKey, "Could not open system:/elektra/version backend. See warnings for details.");
return false;
}
version->global = handle->global;
addMountpoint (handle->backends, keyNew (KDB_SYSTEM_ELEKTRA "/version", KEY_END), version, ksNew (0, KS_END), ksNew (0, KS_END));
return true;
}
/**
* Opens the session with the Key database.
*
* @pre errorKey must be a valid key, e.g. created with keyNew()
*
* You must always call this method before retrieving or committing any
* keys to the database. At the end of a program, after using the Key database (KDB),
* you must not forget to call kdbClose() to free resources.
*
* The method will bootstrap itself in the following way.
* The first step is to open the default backend. With it
* `system:/elektra/mountpoints` will be loaded and all needed
* libraries and mountpoints will be determined.
* Then the global plugins and global keyset data from the @p contract
* is processed.
* Finally, the libraries for backends will be loaded and with it the
* @p KDB data structure will be initialized.
*
* The pointer to the @p KDB structure returned will be initialized
* like described above, and it must be passed along on any kdb*()
* method your application calls.
*
* Get a @p KDB handle for every thread using elektra. Don't share the
* handle across threads, and also not the pointer accessing it:
*
* @snippet kdbopen.c open
*
* You don't need kdbOpen() if you only want to
* manipulate plain in-memory Key or KeySet objects.
*
* @pre errorKey must be a valid key, e.g. created with keyNew()
*
* @param contract the contract that should be ensured before opening the KDB
* all data is copied and the KeySet can safely be used for
* e.g. kdbGet() later
* @param errorKey the key which holds errors and warnings which were issued
*
* @return handle to the newly created KDB on success
* @retval NULL on failure
*
* @since 1.0.0
* @ingroup kdb
* @see kdbClose() to close the session of a Key database opened by kdbOpen()
*/
KDB * kdbOpen (const KeySet * contract, Key * errorKey)
{
if (!errorKey)
{
ELEKTRA_LOG ("no error key passed");
return 0;
}
ELEKTRA_LOG ("called with %s", keyName (errorKey));
Key * initialParent = keyDup (errorKey, KEY_CP_ALL);
int errnosave = errno; // TODO (kodebach) [Q]: really needed?
// Step 1: create empty KDB instance
KDB * handle = kdbNew (errorKey);
if (handle == NULL)
{
goto error;
}
// Step 2: configure for bootstrap
if (!addElektraMountpoint (handle->backends, handle->modules, handle->global, errorKey))
{
goto error;
}
// Step 3: execute bootstrap
KeySet * elektraKs = elektraBoostrap (handle, errorKey);
if (elektraKs == NULL)
{
goto error;
}
// Step 4: setup default global plugins
// TODO (kodebach): remove/replace step in global plugins rewrite
if (mountGlobals (handle, ksDup (elektraKs), handle->modules, errorKey) == -1)
{
// mountGlobals also sets a warning containing the name of the plugin that failed to load
ELEKTRA_SET_INSTALLATION_ERROR (errorKey, "Mounting global plugins failed. Please see warning of concrete plugin");
ksDel (elektraKs);
goto error;
}