so4

[Roytak]

libyang SO4 Notable Changes - serialization, context management, and API refinements

API Changes

Context Options upgraded from u16 to u32

Extension Data Callback (ly_ext_data_clb) parent parameter added

lyplg_type_lypath_free context parameter removed

lyplg_type_validate_patterns context parameter added

Plugin Pointers Replaced by Handles: Pointers to plugins within public lysc_* structs have been replaced by opaque handles plugin_ref

New APIs

Printed Context Support:

• ly_ctx_compiled_size: Returns the size of a compiled context.

• ly_ctx_compiled_print: Serializes (prints) a compiled context.

• ly_ctx_new_printed: Deserializes (creates) a new context from a printed representation.

• ly_ctx_is_printed: Checks if a context was created from a printed representation.

Context Management:

• ly_ctx_free_parsed: Allows explicit freeing of parsed modules within a context.

Plugin Information Retrieval:

• lysc_get_type_plugin: Retrieves a type plugin using its handle from public lysc_* structs.

• lysc_get_ext_plugin: Retrieves an extension plugin using its handle from public lysc_* structs.

• (Internal alternatives: LYSC_GET_TYPE_PLG and LYSC_GET_EXT_PLG)

Schema Mount Contexts Serialization Helpers:

• lyplg_ext_schema_mount_create_shared_context: Creates a shared context before serialization of schema mount contexts.

• lyplg_ext_schema_mount_destroy_shared_contexts: Destroys shared contexts after deserialization.

• lyplg_ext_schema_mount_destroy_inline_contexts: Destroys inline contexts.

Type Plugin Value Printing:

• lyplg_type_print_val: Converts a canonical value to a specific format using a type plugin.

Data Parsing:

• lyd_parse_op: New parse options parameter added.

• lyd_parse_ext_op: New parse options parameter added.

Other Changes:

• Printed (Serializable/Deserializable) Context Support

• New Context Options:

  • LY_CTX_LYB_HASHES: Generates hashes for all schema nodes

  • LY_CTX_STATIC_PLUGINS_ONLY: Restricts context to only use static/global plugins, disallowing user-defined type/extension plugins.

• Context Modules Set Renamed from list to modules

• Distinct Dictionaries for Schema and Data: Schema and data dictionaries are now separate per context => string pointers from data and schema dictionaries can no longer be directly compared.

  • lysdict_* functions are now internal and operate on the schema dictionary.

  • lydict_* functions are public API and operate on the data dictionary.

• Private and Shared Runtime Data of Each context:

  • Private Data: Context-specific and thread-specific. Currently, only errors are stored here.

  • Shared Data: Context-specific but reference-counted, allowing sharing between printed contexts created from the same memory address. Data dictionary, patterns, etc., requires synchronization when accessed.

• Lazy Pattern Compilation: Patterns are now stored in a context's hashtable instead of lysc_pattern and can be compiled lazily only when needed

• Canonical Default Values: Default values are now stored in their canonical form.

Testing Improvements:

• Added new tests for freeing parsed and printed contexts