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| -rw-r--r-- | doc/transition_1_2.dox | 406 | ||||
| -rw-r--r-- | doc/transition_2_3.dox | 74 |
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diff --git a/doc/build.dox b/doc/build.dox new file mode 100644 index 0000000..d5f69b4 --- /dev/null +++ b/doc/build.dox @@ -0,0 +1,139 @@ +/** + * @page build Building libyang + * + * [TOC] + * + * libyang utilizes CMake build system to detect necessary dependencies, checkout the build environment and prepare Makefiles + * for the compilation of the library and acompanied tools. + * + * @section buildRequirements Requirements + * + * @subsection buildRequirementsCompile Building Requirements + * + * - C compiler (gcc, clang, ...) + * - CMake >= 2.8.12 + * - libpcre2 (including headers - devel package) >= 10.30 + * + * @subsubsection buildRequirementsCompileOptional Optional Requirements + * + * - doxygen (for generating documentation) + * - cmocka >= 1.0.0 (for tests) + * - valgrind (for enhanced testing) + * - gcov (for code coverage) + * - lcov (for code coverage) + * - genhtml (for code coverage) + * + * @subsection buildRequirementsRun Runtime Requirements + * + * - libpcre2 (runtime package) >= 10.30 + * + * @section buildCommands Building + * + * To simply build libyang library and the accompanied tools with the default settings, follow these steps (the `#` character + * indicates command(s) to run with `root` privileges): + * + * $ mkdir build; cd build + * $ cmake .. + * $ make + * # make install + * + * The default settings can be changed with various CMake variables set via command line or using e.g. `ccmake(1)` tool. + * The following sections introduces those variables and explain their meaning. + * + * @section buildTypes Build Types + * + * There are several build types according to the primary goal of using the built binaries. + * + * @subsection buildTypesRelese Release + * + * Build type to produce final binaries for production use without any debug option. The compiler flags are set as follows: + * + * -Wall -Wextra -Wno-missing-field-initializers -std=c99 -O3 -DNDEBUG + * + * Here is the list of the selected additional options available in the *Release* build type. + * + * Option | Description | Default + * ----------------------|------------------------------------------------------------------------------------|-------- + * ENABLE_BUILD_TESTS | Build tests. | OFF + * ENABLE_VALGRIND_TESTS | Build tests with valgrind. | OFF + * ENABLE_COVERAGE | Build code coverage report from tests. | OFF + * ENABLE_FUZZ_TARGETS | Build target programs suitable for fuzzing with AFL. | OFF + * BUILD_SHARED_LIBS | Build shared (.so) instead of static (.a) library | ON + * INTERNAL_DOCS | Include developers notes and internal API description into generated Documentation | OFF + * + * Here is the list of available important targets for the `make(1)` tool: + * + * Target | Description + * -------|------------------------------------------------------------------------------------------------------------ + * all | Default target, builds libyang library (.so), `yanglint(1)` and `yangre(1)`. + * clean | Removes files generated by the make process. + * cclean | Extends the `clean` target by removing all the cmake generated files. + * doc | Generate HTML documentation. Requires `doxygen(1)`. + * + * @subsection buildTypesDebug Debug + * + * `Debug` is the default build type, the produced binaries include additional debug information and the prepared tests are + * also built. The compiler flags are set as follows: + * + * -Wall -Wextra -Wno-missing-field-initializers -std=c99 -g3 -O0 + * + * Here is the list of the selected additional options available in the *Debug* build type. + * + * Option | Description | Default + * ----------------------|------------------------------------------------------------------------------------|-------- + * ENABLE_BUILD_TESTS | Build tests. | ON + * ENABLE_VALGRIND_TESTS | Build tests with valgrind. | ON + * ENABLE_COVERAGE | Build code coverage report from tests. | OFF + * ENABLE_FUZZ_TARGETS | Build target programs suitable for fuzzing with AFL. | OFF + * BUILD_SHARED_LIBS | Build shared (.so) instead of static (.a) library | ON + * INTERNAL_DOCS | Include developers notes and internal API description into generated Documentation | OFF + * + * Here is the list of available important targets for the `make(1)` tool: + * + * Target | Description + * -------------|------------------------------------------------------------------------------------------------------ + * all | Default target, builds libyang library (.so), `yanglint(1)` and `yangre(1)`. + * clean | Removes files generated by the make process. + * cclean | Extends the `clean` target by removing all the cmake generated files. + * doc | Generate HTML documentation. Requires `doxygen(1)`. + * test | Run implementation tests. Requires `cmocka` (and `valgrind(1)` for part of the tests). + * format | Reformat source codes using `uncrustify(1)`. + * format-check | Dry-run of the `format` target. + * + * @subsection buildTypesABICheck ABICheck + * + * Special build type to perform check of the ABI/API compatibility and generate reports. In addition to the basic + * requirements, the build type requires some of the <a href="https://abi-laboratory.pro/">ABI Laboratory tools</a>: + * `abi-dumper(1)` and `abi-compliance-checker(1)`. + * + * The compiler flags are set as follows: + * + * -Wall -Wextra -Wno-missing-field-initializers -std=c99 -g -Og + * + * All the additional options are switched OFF and the settings should not be changed. + * + * Here is the list of available important targets for the `make(1)` tool: + * + * Target | Description + * -------------|------------------------------------------------------------------------------------------------------ + * all | Default target, builds libyang library (.so), `yanglint(1)` and `yangre(1)`. + * clean | Removes files generated by the make process. + * cclean | Extends the `clean` target by removing all the cmake generated files. + * doc | Generate HTML documentation. Requires `doxygen(1)`. + * abi-check | Check the backward compatibility of the API/ABI changes. Requires `abi-compliance-checker(1)` and `abi-dump(1)`. + * abi-dump | Helper target for `abi-check` generating API/ABI reports. Requires `abi-dump(1)`. + + * @subsection buildTypesDocOnly DocOnly + * + * Special build type to avoid any requirements except those for building documentation. There are no compiler flags set + * since the build type does not allow building any binary output. The settings of the additional options should not be + * changed. + * + * Here is the list of available important targets for the `make(1)` tool: + * + * Target | Description + * -------------|------------------------------------------------------------------------------------------------------ + * all | Default target, does nothing. + * doc | Generate HTML documentation. Requires `doxygen(1)`. + * + */ diff --git a/doc/cesnet-style.css b/doc/cesnet-style.css new file mode 100644 index 0000000..296c260 --- /dev/null +++ b/doc/cesnet-style.css @@ -0,0 +1,106 @@ +/* CESNET blue: #0068a2 */
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diff --git a/doc/transition_1_2.dox b/doc/transition_1_2.dox new file mode 100644 index 0000000..d116a16 --- /dev/null +++ b/doc/transition_1_2.dox @@ -0,0 +1,406 @@ +/** + * @page transition1_2 Transition Manual (1.x -> 2.0) + * + * [TOC] + * + * Rewriting libyang codebase and creating libyang version 2.0 was motivated mainly by improving long term maintainability. + * Especially some of the features and design decisions become killers for further development and maintaining the libyang + * codebase. On the other hand, most of the principles introduced in libyang 1.x to handle YANG schemas and manipulate + * instantiated data have proved successful. Therefore, we have decided to keep the basic mechanisms from version 1.x and + * remove the problematic features and modify the improper design decisions. Despite the vision to keep with the mechanisms + * also the API, the new version became a great opportunity to clean up the API and improve its usability mainly by unifying + * how the libyang functions are used. So, in the end, this manual is not just a description of the removed features listing + * removed, modified or added functions. The API should be even better prepared for adding new features and functions. + * Shortly, almost everything has changed at least a little, so you cannot move from version 1.x to 2.0 just by replacing + * code snippets. However, we believe that the change is good and libyang 2.0 is simply better. + * + * In this Manual, we want to introduce the differences between libyang 1.x and 2.0. It is intended for the transition + * from 1.x to 2.0, so if you are new to libyang, simply go to the @ref howto section, this Manual is not for you. + * + * The complete generated list of changes (without any additional notes) can be found in + * <a href="../compat_report_1_2.html">the compatibility report</a>. + * + * @section transition1_2General General Changes + * + * + * @subsection transition1_2GeneralErros Errors Handling + * + * The most visible change is probably the changed approach to handling errors. While libyang 1.x was using variable + * *ly_errno* to provide error information in case the called function failed, there is no such variable in libyang 2.0. + * On the other hand, most API functions now return ::LY_ERR values directly stating the result. In addition, in case + * the error is somehow connected with the [context](@ref howtoContext), more detailed error information can be obtained + * from the context handler itself. Mainly this change is responsible for the backward incompatibility of almost all + * functions between versions 1.x and 2.0. + * + * Here is the overview of the changed / removed / added functions connected with errors and logging. + * + * libyang 1.x | libyang 2.0 | Notes + * :-------------------------|:-------------------------------------|:------------------------------------------------------- + * - | ::ly_err_last() | New API for handling errors. + * ly_verb_dbg() | ::ly_log_dbg_groups() | Rename to align with the names of the accepted values. + * ly_verb() | ::ly_log_level() | ^ + * + * More information about error handling in libyang 2.0 can be found at @ref howtoErrors page. + * + * @subsection transition1_2GeneralInOut Input / Output Processing + * + * libyang 2.0 introduces input (::ly_in) and output (::ly_out) handlers covering the specific input sources for parsers and + * output targets for printers. They are supposed mainly to simplify parser's and printer's API to avoid the need for + * separate functions for each source/target. The handlers can be used repeatedly to split the inputs or join the outputs. + * + * More information can be found at @ref howtoInput and @ref howtoOutput pages. + * + * + * @subsection transition1_2GeneralOutputFormatting Output Formatting + * + * In libyang 1.x, there was an inconsistency in printing schemas and data. While the schemas were always printed formatted, + * the data were printed by default without additional indentation. It is clearly visible in the YIN format of the schema, + * which is XML, and the XML encoding of the data. While there was a possibility to format data output with the LYP_FORMAT + * flag, it wasn't possible to change schema output formatting. + * + * libyang 2.0 unifies the behavior of all printers. By default, all the output formats are formatted now. Both, the data as + * well as the schema printers, accept the option to remove additional formatting (different for the specific format, usually + * indentations and blank lines): ::LYD_PRINT_SHRINK for the data printer and ::LYS_PRINT_SHRINK for the schema printer. + * + * + * @subsection transition1_2GeneralXPath Addressing + * + * If you compare the @ref howtoXPath page from libyang 1.x and 2.0 documentation, you will be probably confused since they + * seem very different. In fact, we have tried to simplify the API by removing the original Schema path format from the + * public API. Since this format is used in YANG format, libyang still supports it internally, but it is not possible to use + * it anywhere in the API. The new formats XPath and Path, mentioned at the @ref howtoXPath page, are both the Data paths + * used in libyang 1.x. The Path format is a subset of XPath format limited to refer to a single node. + * + * This change was reflected in functions serving to get a node based on the specified path. Unfortunately, when comparing + * old and new API, the transition can be confusing since the names are sometimes overloaded (be careful mainly of + * ::lys_find_path()). The following table depicts the changes, but probably a better approach is to handle the functions as + * a completely new API. + * + * libyang 1.x | libyang 2.0 | Notes + * :-------------------------|:-------------------------------------|:------------------------------------------------------- + * ly_ctx_find_path() | - | To simplify the different [types of paths](@ref howtoXPath), the Schema path format is not supported for now. If there will be use cases for it, it can be re-added later, but for now try using ::lys_find_xpath(). + * %lys_find_path() | - | To simplify the different [types of paths](@ref howtoXPath), the Schema path format is not supported for now. If there will be use cases for it, it can be re-added later, but for now try using ::lys_find_xpath(). + * ly_ctx_get_node() | ::lys_find_path() | Renamed to unify API functions, note that there was lys_find_path in libyang 1.x with different functionality in comparison to the function of the same name from libyang 2.0. + * - | ::lys_find_path_atoms() | Extension of ::lys_find_path(). + * - | ::lys_find_lypath_atoms() | ^ + * - | ::lys_find_xpath() | New function reflecting updated @ref howtoXPath\. + * lys_xpath_atomize() | ::lys_find_xpath_atoms() | Rename to unify with the new API, extends ::lys_find_xpath(). + * - | ::lys_find_expr_atoms() | Extension of ::lys_find_xpath(). + * %lyd_path() | ::lyd_path() | Same purpose, just extended functionality. + * lyd_find_path() | ::lyd_find_xpath() | Rename to unify with the new API. + * - | ::lyd_find_path() | Simplified version of ::lyd_find_path(). + * - | ::lyxp_get_expr() | Added functionality due to the changed representation of XPath expressions. + * ly_path_data2schema() | - | Removed since the schema path is not available in API. + * ly_path_xml2json() | - | Removed since done internally, note that even the generic XML parser is not available now. + * lys_node_xpath_atomize() | - | Removed as useless/redundant, use ::lys_find_xpath_atoms(). + * + * @section transition1_2Context Context + * + * Context, as a concept of a storage interconnecting YANG modules into a YANG schema and YANG schema with the instantiated + * data, was preserved. However, it is now more supposed to be prepared just once before connecting it with any instantiated + * data. The possibility of removing YANG modules from the context was completely dropped. Furthermore, we would like to + * introduce some kind of context lock to completely abandon any change of the YANG modules after starting work with the + * instantiated data. + * + * Another change to note is the removed destructor of private data (::lysc_node.priv) in ::ly_ctx_destroy(). The mechanism + * was not reliable with the context recompilation and the splitted parsed and compiled schema trees or the complexity of + * YANG extensions. It is better to let the caller maintain the allocated data directly via some memory pool or using + * ::lysc_tree_dfs_full() since he is the best to know where the additional data were added. + * + * The meaining of the ::lysc_node.priv pointer can be now also changed by ::LY_CTX_SET_PRIV_PARSED context option, which + * makes libyang to connect the original parsed schema node structure (::lysp_node) into the compiled nodes via their 'priv' + * pointer. + * + * Other significant changes connected with the context are depicted in the following table. + * + * libyang 1.x | libyang 2.0 | Notes + * :-------------------------|:-------------------------------------|:------------------------------------------------------- + * ly_ctx_clean() | - | Removed functionality of manipulating with the context and the modules already placed in the context. + * ly_ctx_remove_module() | - | ^ + * ly_ctx_set_module_data_clb() and the associated ly_module_data_clb type. | - | ^ + * ly_ctx_get_disabled_module() and the associated ly_ctx_get_disabled_module_iter() | - | ^ + * ly_ctx_info() | ::ly_ctx_get_yanglib_data() | Clarification of what to expect as the output of the function and possibility to specify custom content ID. + * ly_ctx_get_module_set_id() | ::ly_ctx_get_change_count() | The functionality is the same but the exact meaning of the value was clarified. + * - | ::ly_ctx_unset_searchdir_last() | Extend the functionality of the ::ly_ctx_unset_searchdir() to make its use easier. + * ly_ctx_get_module_older() | - | Removed functionality. + * - | ::ly_ctx_get_module_implemented() | Supplement for ::ly_ctx_get_module() + * - | ::ly_ctx_get_module_latest() | ^ + * - | ::ly_ctx_get_module_implemented_ns() | Supplement for ::ly_ctx_get_module_ns() + * - | ::ly_ctx_get_module_latest_ns() | ^ + * - | ::ly_ctx_get_submodule_latest() | Supplement for ::ly_ctx_get_submodule() + * - | ::ly_ctx_get_submodule2_latest() | Supplement for ::ly_ctx_get_submodule2() + * ly_ctx_get_module_by_ns() | ::ly_ctx_get_module_ns () | Redesign the API - replace some of the parameters with standalone supplement functions. + * ly_ctx_unset_searchdirs() | ::ly_ctx_unset_searchdir() | Simplify API and instead of index numbers, work with the values themselves. + * ly_ctx_set*() | ::ly_ctx_set_options() | API simplification. + * ly_ctx_unset*() | ::ly_ctx_unset_options() | ^ + * ly_ctx_destroy() | ::ly_ctx_destroy() | The destructor callback parameter was removed, see the notes above. + * + * + * @section transition1_2Schemas YANG Modules (Schema) + * + * The most significant change between libyang 1.x and 2.0 can be found in schema structures. The schema tree now has two + * different forms - parsed and compiled trees. While the parsed tree reflects the source of the YANG module, the compiled + * tree represents the final tree used to validate the instantiated data. Both formats can be found inside the covering + * ::lys_module structure. More about the new structures can be found at @ref howtoSchema page. + * + * This is an essential change allowing speed up and simplification of data validation, but requiring carefully determine + * which format is more suitable for the specific use case. As mentioned, the compiled trees are better for data validation + * and getting information about the intentioned structure of the schema with all the applied groupings, type modifications, + * augments, deviations, and any defined if-features. On the other hand, the parsed trees are useful for the schema format conversions since they + * provide the original structure of the modules. There is a number of new functions intended to work only with the + * parsed or the compiled tree. These functions are prefixed with `lysp_` and `lysp_` prefixes. + * + * Schema parser, as well as printer functions, are now extended to accept new + * [input / output handlers](@ref transition1_2GeneralInOut). The previous API working directly with inputs and outputs is + * preserved (or slightly changed), but the functions can be limited in the functionality of the new API. More information + * can be found at @ref howtoSchemaParsers and @ref howtoSchemaPrinters pages. + * + * libyang 1.x | libyang 2.0 | Notes + * :----------------------------|:--------------------------------|:--------------------------------------------------------- + * - | ::lys_parse() | New generic schema parser API using [generic input handler](@ref howtoInput). + * - | ::lys_print_module() | New generic schema printer API using [generic output handler](@ref howtoOutput). + * - | ::lys_print_node() | ^ + * - | ::lys_print_submodule() | ^ + * + * + * The following table introduces other significant changes in the API functions connected with the schema. + * + * libyang 1.x | libyang 2.0 | Notes + * :----------------------------|:--------------------------------|:--------------------------------------------------------- + * lys_set_private() | - | Not needed, all ::lysc_node compatible structures have this pointer so it can be accessed directly. + * lys_is_disabled() | - | Make no sense since the nodes disabled by if-feature are not present in the compiled tree. + * lys_features_list() | - | Not needed, the list of features is available in the parsed tree of the module and submodule. + * lys_features_enable(), lys_features_enable_force() | ::lys_set_implemented() | Set of enabled features can be changed but it causes the whole context (all the modules) to recompile. + * lys_features_disable(), lys_features_disable_force() | - | ^ + * lys_features_state() | - | Redesign of the features handling in the schema tree, the feature's status is newly directly visible as ::LYS_FENABLED flag (in parsed feature structure). + * - | ::lys_feature_value() | Simplified API to get feature's state only based on a feature name string. + * - | ::lysp_feature_next() | After redesigning features handling, this function helps to iterate over all features connected with the module. + * lys_iffeature_value() | ::lysc_iffeature_value() | Renamed, but note that after features handling redesign, the compiled if-feature structure to evaluate is only in ::lysp_feature.iffeatures_c. + * lys_iffeature_value() | - | Not needed since the if-feature statements are directly applied onto the compiled tree. + * lys_is_disabled() | - | ^ + * lys_parent() | - | The compiled tree is more straightforward without the need to take care of nodes added via augments. + * lys_main_module() | - | The compiled tree does not include submodules, so there is always only the main module. + * lys_node_module() | - | ^ + * lys_set_enabled() | - | It is not possible to change context this way (remove or disable modules). + * lys_set_disabled() | - | ^ + * - | ::lys_find_child() | Helpers wrapper around ::lys_getnext(). + * - | ::lys_getnext_ext() | Alternative to ::lys_getnext() allowing processing schema trees inside extension instances. + * - | ::lys_nodetype2str() | New functionality. + * lys_is_key() | ::lysc_is_key() | Renamed to connect with the compiled schema tree. + * - | ::lysc_is_userordered() | Added functionality to simplify the examination of generic compiled schema nodes. + * - | ::lysc_is_np_cont() | ^ + * - | ::lysc_node_child() | ^ + * - | ::lysc_node_actions() | ^ + * - | ::lysc_node_notifs() | ^ + * - | ::lysp_node_child() | Added functionality to simplify the examination of generic parsed schema nodes. + * - | ::lysp_node_actions() | ^ + * - | ::lysp_node_notifs() | ^ + * - | ::lysp_node_groupings() | ^ + * - | ::lysp_node_typedefs() | ^ + * - | ::lysc_tree_dfs_full() | Alternative DFS passing implementation to ::LYSC_TREE_DFS_BEGIN macro. + * - | ::lysc_module_dfs_full() | Supplement functionality to ::lysc_tree_dfs_full(). + * lys_path(), lys_data_path() | ::lysc_path() | Redesigned functionality. + * lys_data_path_pattern() | - | Removed as useless + * lys_implemented_module() | ::ly_ctx_get_module_implemented() | Removed, the same result can be simply achieved using ::ly_ctx_get_module_implemented(). + * + * There is a set of functions available to implement data type plugins for storing and manipulating data values in a more + * natural way to the specific data type. For example, IPv4 address type is defined as a string with a pattern, but it is + * more effective and usual to store and handle IPv4 as a 32-bit number. + * + * libyang 1.x | libyang 2.0 | Notes + * :----------------------------|:---------------------------------|:-------------------------------------------------------- + * lys_getnext_union_type() | - | Removed after the type representation redesign. + * - | ::lyplg_type_identity_isderived()| Helper functions for base types. + * - | ::lyplg_type_parse_dec64() | ^ + * - | ::lyplg_type_parse_int() | ^ + * - | ::lyplg_type_parse_uint() | ^ + * - | ::lyplg_type_validate_patterns() | ^ + * - | ::lyplg_type_validate_range() | ^ + * - | ::lyplg_type_get_prefix() | Helper functions for processing prefixes in data values. + * - | ::lyplg_type_prefix_data_new() | ^ + * - | ::lyplg_type_prefix_data_dup() | ^ + * - | ::lyplg_type_prefix_data_free() | ^ + * + * + * YANG extensions are supported via [extension plugins API](@ref pluginsExtensions) allowing to implement specific extension + * and load its support into libyang as a shared module. libyang implements several extensions on its own (see + * @ref howtoPluginsExtensions), but even these internal implementations use the same API. The API and [mechanism of loading + * external plugins](@ref howtoPlugins) changed a lot in contrast to libyang 1.x. The plugins are now loaded automatically + * with creating the first libyang context. The only public function to handle external plugins is ::lyplg_add(). + * + * + * libyang 1.x | libyang 2.0 | Notes + * :----------------------------|:--------------------------------|:--------------------------------------------------------- + * lys_ext_complex_get_substmt()| lysc_ext_substmt() | Changed design of the extensions and the way how it's substatements are accessed. + * lys_ext_instance_presence() | lysc_ext_substmt() | ^ + * lys_ext_instance_substmt() | lysc_ext_substmt() | ^ + * ly_clean_plugins() | - | Manipulating external plugins (from plugins directories) is now automatically connected with creating (first) and destroying (last) libyang contexts. + * ly_get_loaded_plugins() | - | ^ + * ly_load_plugins() | - | ^ + * ly_register_exts() | ::lyplg_add() | Redesigned to a common function for any plugin type. + * ly_register_types() | ::lyplg_add() | ^ + * + * + * @section transition1_2Data Data Instances + * + * Conceptually, the data tree did not change as much as the schema tree. There is still a generic ::lyd_node structure that + * maps according to the schema node's nodetype to some of the other lyd_node_* structures. All the data nodes were extended + * by hashes to improve performance when searching and processing data trees. The hashes are used for example in the + * lyd_find_* functions. + * + * All the data nodes are also implicitly ordered following the order of the schema nodes. This is the + * reason to change the insertion function. Only the user-ordered lists and leaf-lists can be now placed relative to other + * instances of the same list/leaf-list. Otherwise, the data instance is always inserted/created at the correct place beside + * the right sibling nodes. + * + * For any functions that are available on inputs of different scale (node, subtree, all siblings, whole data tree), + * there are several variants of the specific function with suffix specifying what exactly the processed input will be + * (_single, _tree, _siblings, _all). This way the behavior is always clear in the code. + * + * libyang 1.x | libyang 2.0 | Notes + * :----------------------------|:--------------------------------|:--------------------------------------------------------- + * %lyd_insert_after() | ::lyd_insert_after() | Changed meaning by limiting applicability only to user-ordered list and leaf-list instances. + * %lyd_insert_before() | ::lyd_insert_before() | ^ + * lyd_schema_sort() | - | Not necessary since the nodes are sorted implicitly. + * + * + * Parsing data instances in XML format is newly done directly, without any interstep. Therefore, complete XML API + * (lyxml_*() functions) from libyang 1.x was removed. + * + * Parser's API was simplified to avoid variadic parameters. The functions are newly split to parsed data, notifications, + * RPCs and replies to the RPCs. Similarly to the schema parsers, also the new data parser API works with + * [input handlers](@ref transition1_2GeneralInOut). The data printer's API was also extended to use new + * [output handlers](@ref transition1_2GeneralInOut). However, part of the previous API working directly with inputs + * and outputs was preserved. More information about the data parser and printer can be found at + * @ref howtoDataParsers and @ref howtoDataPrinters pages. + * + * libyang 1.x | libyang 2.0 | Notes + * :----------------------------|:--------------------------------|:--------------------------------------------------------- + * - | ::lyd_parse_data() | Redesigned data tree parser. + * lyd_parse_xml() | - | XML tree format was removed. + * lyd_parse_fd() | ::lyd_parse_data_fd() | Renamed and limited to data trees only. + * lyd_parse_mem() | ::lyd_parse_data_mem() | ^ + * lyd_parse_path() | ::lyd_parse_data_path() | ^ + * - | ::lyd_parse_ext_data() | Separated function for parsing data trees matching a schema tree of the given extension instance. + * - | ::lyd_parse_op() | Separated function for parsing RPCs, actions, replies, and notifications. + * - | ::lyd_parse_ext_op() | Separated function for parsing RPCs, actions, replies, and notifications of the given extension instance. + * - | ::lyd_print_all() | New API accepting ::ly_out. + * - | ::lyd_print_tree() | ^ + * + * + * Data validation is still done as part of the parser's process. The standalone functionality is available to check the + * result of data manipulation with the values of the terminal nodes or with the structure of the data tree. In contrast to + * libyang 1.x, adding the default nodes was made available as a standalone function to simplify the data manipulation + * process before the final validation. + * + * Many validation flags were removed because they became obsolete (LYD_OPT_DESTRUCT, LYD_OPT_WHENAUTODEL, + * LYD_OPT_NOEXTDEPS, LYD_OPT_DATA_NO_YANGLIB, LYD_OPT_VAL_DIFF) or we consider them redundant (LYD_OPT_OBSOLETE, + * LYD_OPT_NOSIBLINGS, LYD_OPT_DATA_ADD_YANGLIB). As for LYD_OPT_TRUSTED, this option was mostly replaced with + * ::LYD_PARSE_ONLY because both skip validation but with the significant difference that LYD_OPT_TRUSTED also sets + * the data node flags to be considered validated. The current option ::LYD_PARSE_ONLY does not do this because + * there is now much better support for working with non-validated data trees. Also, in case an invalid tree was marked + * as validated, it could lead to some undesired behavior, which is now avoided. + * + * Worth mentioning is a difference in the LYB format, which now also stores its validation flags. So, in case + * a validated data tree is stored, it is also loaded as validated. + * + * libyang 1.x | libyang 2.0 | Notes + * :----------------------------|:--------------------------------|:--------------------------------------------------------- + * lyd_validate() | ::lyd_validate_all(), ::lyd_validate_op() | Redesigned functionality. + * lyd_validate_modules() | ::lyd_validate_module() | ^ + * lyd_validate_value(), lyd_value_type() | ::lyd_value_validate() | Redesigned functionality. + * - | ::lyd_new_implicit_all() | New in API to explicitly add default nodes, previously done only as part of the validation process. + * - | ::lyd_new_implicit_module() | Supplement functionality to ::lyd_new_implicit_all(). + * - | ::lyd_new_implicit_tree() | ^ + * + * + * The `diff` functionality was completely redesigned. Instead of the array of operations to transform one tree into another, + * the difference between two data trees has newly a form of the annotated data tree describing the differences. A number of + * functions to use the diff tree was added into API. To simply compare just nodes, there are the `compare` functions. + * + * libyang 1.x | libyang 2.0 | Notes + * :----------------------------|:--------------------------------|:--------------------------------------------------------- + * lyd_diff() | ::lyd_diff_tree() | Redesigned functionality. + * - | ::lyd_diff_siblings() | Supplement functionality to ::lyd_diff_tree(). + * - | ::lyd_diff_apply_all() | ^ + * - | ::lyd_diff_apply_module() | ^ + * - | ::lyd_diff_merge_all() | ^ + * - | ::lyd_diff_merge_module() | ^ + * - | ::lyd_diff_merge_tree() | ^ + * - | ::lyd_diff_reverse_all() | ^ + * lyd_free_diff() | - | Removed. + * lyd_free_val_diff() | - | Removed. + * - | ::lyd_compare_single() | Added functionality. + * - | ::lyd_compare_meta() | Supplement functionality to ::lyd_compare_single() + * - | ::lyd_compare_siblings() | ^ + * + * + * For now, the functionality of moving data between two different contexts is not implemented. If you have a real use case + * for this functionality, let us know. + * + * libyang 1.x | libyang 2.0 | Notes + * :----------------------------|:--------------------------------|:--------------------------------------------------------- + * lyd_dup() | ::lyd_dup_single() | Redesigned functionality. + * lyd_dup_withsiblings() | ::lyd_dup_siblings() | ^ + * - | ::lyd_dup_meta_single() | Supplement functionality to ::lyd_dup_single(). + * lyd_dup_to_ctx() | - | Transferring data from one context to another is not supported. + * lyd_merge() | ::lyd_merge_tree() | Renamed. + * - | ::lyd_merge_siblings() | Supplement functionality to ::lyd_merge_tree() + * lyd_merge_to_ctx() | - | Transferring data from one context to another is not supported. + * + * + * There is a significant change in the value structure in terminal nodes. Thanks to the changes in the schema tree, + * it is now much more straightforward to get the type of the value and work with the alternative representation of the value + * fitting better to its type. There is also a new API for the type plugins (see @ref howtoPluginsTypes). Even the base YANG + * data types are now implemented using this API and can be taken as examples for implementing derived data types. + * + * libyang 1.x | libyang 2.0 | Notes + * :----------------------------|:--------------------------------|:--------------------------------------------------------- + * lyd_new(), lyd_new_output() | ::lyd_new_inner(), ::lyd_new_list(), ::lyd_new_list2() | Redesigned functionality to better fit new lyd_node structures, creating RPC's output data is now done via a flag parameter of the functions. + * lyd_new_leaf(), lyd_new_output_leaf() | ::lyd_new_term() | ^ + * lyd_new_anydata(), lyd_new_output_anydata() | ::lyd_new_any() | ^ + * lyd_new_yangdata() | ::lyd_new_ext_inner(), ::lyd_new_ext_list(), ::lyd_new_ext_term(), ::lyd_new_ext_any() | Additional functionality to lyd_new_* functions to cover top-level nodes in extension instances. + * lyd_insert_attr() | ::lyd_new_meta() | Unify naming used in other functions with the similar functionality. + * - | ::lyd_new_attr() | Added functionality to store the data (temporarily) not connected with schema definitions. + * - | ::lyd_new_attr2() | ^ + * - | ::lyd_new_opaq() | ^ + * - | ::lyd_new_opaq2() | ^ + * - | ::lyd_new_path2() | Supplement functionality to ::lyd_new_path(). + * LYD_PATH_OPT_NOPARENTRET | ::lyd_new_path2() | ::lyd_new_path2() returns both the first parent and the wanted node. + * LYD_PATH_OPT_EDIT | ::LYD_NEW_PATH_OPAQ | This functionality was replaced by opaq nodes. + * - | ::lyd_new_ext_path() | Supplement functionality to ::lyd_new_path() covering data defined in extension instances. + * lyd_insert() | ::lyd_insert_child() | Renamed to better distinguish from ::lyd_insert_sibling(). + * lyd_change_leaf() | ::lyd_change_term() | Align naming with changed names of data structures. + * - | ::lyd_change_meta() | Transferred functionality of ::lyd_change_term() to metadata. + * - | ::lyd_any_copy_value() | Added functionality. + * lyd_free() | ::lyd_free_tree() | Renamed. + * lyd_free_withsiblings() | ::lyd_free_all() | ^ + * - | ::lyd_free_siblings() | Supplement functionality to ::lyd_free_siblings(). + * lyd_free_attr() | ::lyd_free_attr_single() | Renamed. + * - | ::lyd_free_attr_siblings() | Supplement functionality to ::lyd_free_attr_single(). + * - | ::lyd_free_meta_single() | Added functionality. + * - | ::lyd_free_meta_siblings() | ^ + * lyd_unlink() | ::lyd_unlink_tree() | Renamed. + * + * + * Here is the table of other changes in data API. + * + * libyang 1.x | libyang 2.0 | Notes + * :----------------------------|:--------------------------------|:--------------------------------------------------------- + * lyd_find_instance() | - | Removed. + * lyd_find_sibling() | - | Removed, functionality can be replaced by ::lyd_find_sibling_val(). + * lyd_find_sibling_set() | - | ^ + * - | ::lyd_find_sibling_first() | Alternative function to ::lyd_find_sibling_val(). + * - | ::lyd_find_meta() | New functionality. + * lyd_wd_default() | ::lyd_is_default() | Renamed to unlink from with-default capability. + * - | ::lyd_parent() | New wrapper to get generic ::lyd_node pointer of the parent. + * - | ::lyd_child(), ::lyd_child_no_keys() | New wrapper to cover all children possibilities hidden behind a generic ::lyd_node structure. + * - | ::lyd_owner_module() | Added functionality. + * - | ::lyd_value_compare() | Added Functionality. + * - | ::lyd_find_target() | Added functionality for the instance-identifier representation. + * lyd_node_module() | - | Not necessary since the connection with the compiled modules is much more straightforward. + * lyd_leaf_type() | - | Not necessary since the real type information is much more clear from the new ::lyd_value. + * lyd_dec64_to_double() | - | Removed as useless. + * lyd_node_should_print() | - | ^ + + */ diff --git a/doc/transition_2_3.dox b/doc/transition_2_3.dox new file mode 100644 index 0000000..87e3dcf --- /dev/null +++ b/doc/transition_2_3.dox @@ -0,0 +1,74 @@ +/** + * @page transition2_3 Transition Manual (2.x -> 3.0) + * + * [TOC] + * + * Non-backwards-compatible changes between libyang version 2 and 3 are rather minor and can be summarized as providing + * structured error information (instead of a single message), unifying **lyd_new_*()** function options, and some + * minor changes such as removing deprecated functions or making a few functions inlined. However, there is another + * large change that has not affected the API, specifically configuration system-ordered lists and leaf-lists are now + * ordered based on their keys/values, respectively. Except for moderately slower performance and negligible increased + * memory requirements, it should not affect existing applications (assuming they do not rely on the previous order of + * these instances). + * + * The complete generated list of changes (without any additional notes) can be found in + * <a href="../compat_report_2_3.html">the compatibility report</a>. + * + * @section transition2_3Logging Logging + * + * Except for some function adjustments, ::ly_err_item has been changed to provide every piece of error information in a + * separate member to allow for easier processing. + * + * Here is the overview of the changed / removed / added functions connected to logging. + * + * libyang 2.x | libyang 3.0 | Notes + * :-------------------------|:-------------------------------------|:------------------------------------------------------- + * ly_last_errmsg() | ::ly_last_logmsg() | Function renamed with the same functionality. + * ly_strerrcode() | ::ly_strerr() | Function renamed with the same functionality. + * ly_errcode() | - | Now requires ::ly_err_last() call. + * ly_errmsg() | - | ^ + * ly_errpath() | - | ^ + * ly_vecode() | - | ^ + * + * + * + * @section transition2_3New Data Creation + * + * libyang 2.x | libyang 3.0 | Notes + * :-------------------------|:-------------------------------------|:------------------------------------------------------- + * lyd_find_xpath3() | ::lyd_find_xpath3() | Optional prefix data parameter added. + * LYD_NEW_PATH_OUTPUT | ::LYD_NEW_VAL_OUTPUT | Some LYD_NEW_PATH_* options now also used for other lyd_new_* functions. + * LYD_NEW_PATH_BIN_VALUE | ::LYD_NEW_VAL_BIN | ^ + * LYD_NEW_PATH_CANON_VALUE | ::LYD_NEW_VAL_CANON | ^ + * lyd_new_path() | ::lyd_new_path() | All options now in a single bitmap parameter of @ref newvaloptions. + * lyd_new_any() | ::lyd_new_any() | ^ + * lyd_new_list() | ::lyd_new_list() | ^ + * lyd_new_list2() | ::lyd_new_list2() | ^ + * lyd_new_list3() | ::lyd_new_list3() | ^ + * lyd_new_meta() | ::lyd_new_meta() | ^ + * lyd_new_meta2() | ::lyd_new_meta2() | ^ + * lyd_new_term() | ::lyd_new_term() | ^ + * lyd_new_list3_bin() | ::lyd_new_list3() | Functionality now merged into the single function. + * lyd_new_list3_canon() | ^ | ^ + * lyd_new_list_bin() | ::lyd_new_list() | Functionality now merged into the single function. + * lyd_new_list_canon() | ^ | ^ + * lyd_new_term_canon() | ::lyd_new_term() | Functionality now merged into the single function. + * + * + * + * @section transition2_3Minor Other Minor Changes + * + * Except for the function changes below, ::lysc_type now has a copy of the typedef name, if applicable. There + * are use-cases when this information is needed even in the compiled schema tree such as checking the real type of + * a union value. + * + * libyang 2.x | libyang 3.0 | Notes + * :-------------------------|:-------------------------------------|:------------------------------------------------------- + * lyd_child() | ::lyd_child() | Now an inlined function for better performance. + * lyd_get_value() | ::lyd_get_value() | ^ + * lyd_parent() | ::lyd_parent() | ^ + * lyd_find_xpath4() | ::lyd_find_xpath3() | Previous lyd_find_xpath3 was removed to reduce symbols. + * lyd_target() | - | Deprecated. + * ly_ctx_reset_latests() | - | ^ + * + */ |