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diff --git a/src/log.h b/src/log.h new file mode 100644 index 0000000..85f2ac6 --- /dev/null +++ b/src/log.h @@ -0,0 +1,361 @@ +/** + * @file log.h + * @author Radek Krejci <rkrejci@cesnet.cz> + * @author Michal Vasko <mvasko@cesnet.cz> + * @brief Logger manipulation routines and error definitions. + * + * Copyright (c) 2015 - 2022 CESNET, z.s.p.o. + * + * This source code is licensed under BSD 3-Clause License (the "License"). + * You may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * https://opensource.org/licenses/BSD-3-Clause + */ + +#ifndef LY_LOG_H_ +#define LY_LOG_H_ + +#include <stdint.h> + +#include "ly_config.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* dummy context structure */ +struct ly_ctx; + +/** + * @brief Type to indicate boolean value. + * + * Do not test for actual value. Instead, handle it as true/false value in condition. + */ +typedef uint8_t ly_bool; + +/** + * @page howtoLogger Information Logging + * + * The libyang logger is supposed to process all the messages (and some other accompanied information) generated by the performed + * functions. According to the logger settings, the information can be printed, stored or further processed by a callback + * functions. + * + * The logger is tightly connected with [errors handling](@ref howtoErrors), because when an error appears, the logger (according + * to [logger options](@ref logopts)) generates error records available via libyang context. + * + * There are 4 verbosity levels defined as ::LY_LOG_LEVEL. The level can be changed by the ::ly_log_level() function. + * By default, the verbosity level is set to #LY_LLERR value, so only the errors are processed. + * + * By default, all libyang messages are printed to `stderr`. However, the callers are able to set their own logging callback + * function (::ly_log_clb). In that case, instead of printing messages, libyang passes error level, message and path (if any) to + * the caller's callback function set via ::ly_set_log_clb(). In case of error level, the error information is still + * automatically stored and available via the [error handling functions](@ref howtoErrors). + * + * With [logging options](@ref logopts) set via ::ly_log_options(), the caller can modify what is done with all the messages. + * Default flags are ::LY_LOLOG and ::LY_LOSTORE_LAST so that messages are logged and the last one is stored. If you set the flag + * ::LY_LOSTORE, all the messages will be stored. Be careful because unless you regularly clean them, the error list in context + * will grow indefinitely. + * + * As a separate group, there are @ref dbggroup to select group of debugging messages to print. The options can be set via + * ::ly_log_dbg_groups() function, but note that the options take effect only in case the libyang is compiled in + * [Debug build mode](@ref build). + * + * \note API for this group of functions is described in the [logger module](@ref log). + * + * Functions List + * -------------- + * - ::ly_log_level() + * - ::ly_log_dbg_groups() + * - ::ly_log_options() + * - ::ly_set_log_clb() + * - ::ly_get_log_clb() + * + */ + +/** + * @defgroup log Logger + * @{ + * + * Publicly visible functions and values of the libyang logger. For more + * information, see @ref howtoLogger. + */ + +/** + * @typedef LY_LOG_LEVEL + * @brief Verbosity levels of the libyang logger. + */ +typedef enum { + LY_LLERR = 0, /**< Print only error messages. */ + LY_LLWRN = 1, /**< Print error and warning messages, default value. */ + LY_LLVRB = 2, /**< Besides errors and warnings, print some other verbose messages. */ + LY_LLDBG = 3 /**< Print all messages including some development debug messages (be careful, + without subsequently calling ::ly_log_dbg_groups() no debug messages will be printed!). */ +} LY_LOG_LEVEL; + +/** + * @brief Set logger verbosity level. + * + * To get the current value, the function must be called twice resetting the level by the received value. + * + * @param[in] level Verbosity level. + * @return Previous verbosity level. + */ +LIBYANG_API_DECL LY_LOG_LEVEL ly_log_level(LY_LOG_LEVEL level); + +/** + * @ingroup log + * @defgroup logopts Logging options + * + * Logging option bits of libyang. + * + * Can be set via ::ly_log_options(). + * + * @{ + */ +#define LY_LOLOG 0x01 /**< Log messages normally, using callback if set. If not set, messages will + not be printed by libyang. */ +#define LY_LOSTORE 0x02 /**< Store any generated errors or warnings, never verbose or debug messages. + Note that if #LY_LOLOG is not set then verbose and debug messages are always lost. */ +#define LY_LOSTORE_LAST 0x06 /**< Store any generated errors or warnings but only the last message, always overwrite + the previous one. */ + +/** + * @} + */ + +/** + * @brief Set logger options. Default is #LY_LOLOG | #LY_LOSTORE_LAST. + * + * To get the current value, the function must be called twice resetting the level by the received value. + * + * @param[in] opts Bitfield of @ref logopts. + * @return Previous logger options. + */ +LIBYANG_API_DECL uint32_t ly_log_options(uint32_t opts); + +/** + * @brief Set temporary thread-safe logger options overwriting those set by ::ly_log_options(). + * + * @param[in] opts Pointer to the temporary @ref logopts. If NULL, restores the effect of global logger options. + * @return Previous temporary options. + */ +LIBYANG_API_DECL uint32_t *ly_temp_log_options(uint32_t *opts); + +/** + * @ingroup log + * @defgroup dbggroup Debug messages groups + * + * Categories of the debug messages. + * + * Allows to show only the selected group(s) of the debug messages. + * + * @{ + */ + +#define LY_LDGDICT 0x01 /**< Dictionary additions and deletions. */ +#define LY_LDGXPATH 0x02 /**< XPath parsing end evaluation. */ +#define LY_LDGDEPSETS 0x04 /**< Dependency module sets for schema compilation. */ + +/** + * @} + */ + +/** + * @brief Enable specific debugging messages (independent of log level). + * + * To get the current value, the function must be called twice resetting the level by the received value. + * Note: does not have any effect on non-debug (Release) builds + * + * @param[in] dbg_groups Bitfield of enabled debug message groups (see @ref dbggroup). + * @return Previous options bitfield. + */ +LIBYANG_API_DECL uint32_t ly_log_dbg_groups(uint32_t dbg_groups); + +/** + * @brief Logger callback. + * + * @param[in] level Log level of the message. + * @param[in] msg Message. + * @param[in] data_path Optional data path of the related node. + * @param[in] schema_path Optional schema path of the related node. + * @param[in] line Optional related input line. + */ +typedef void (*ly_log_clb)(LY_LOG_LEVEL level, const char *msg, const char *data_path, const char *schema_path, + uint64_t line); + +/** + * @brief Set logger callback. + * + * @param[in] clb Logging callback. + */ +LIBYANG_API_DECL void ly_set_log_clb(ly_log_clb clb); + +/** + * @brief Get logger callback. + * + * @return Logger callback (can be NULL). + */ +LIBYANG_API_DECL ly_log_clb ly_get_log_clb(void); + +/** @} log */ + +/** + * @page howtoErrors Errors Handling + * + * The most of the API functions directly returns error code in the form of ::LY_ERR value. In addition, if the ::LY_EVALID error + * arises, additional [validation error code](@ref ::LY_VECODE) is provided to categorize validation failures into several groups. + * + * All the errors arisen in connection with manipulation with the [context](@ref howtoContext), [YANG modules](@ref howtoSchema) + * or [YANG data](@ref howtoData), are recorded into the context and can be examined for the more detailed information. These + * records are stored as ::ly_err_item structures and they are not only context-specific, but also thread-specific. + * + * Storing error information is tightly connected with + * [logging](@ref howtoLogger). So the @ref logopts control if and which errors are stored in the context. By default, only the + * last error is recorded, so a new error replaces the previous one. This can be changed with ::LY_LOSTORE option set via + * ::ly_log_options(). Then, the errors are stored as a list preserving the previous error records. The stored records can be + * accessed using ::ly_err_last() or ::ly_err_first() functions. The ::ly_err_clean() is used to remove error records from the + * context. + * + * To print a specific error information via libyang logger, there is ::ly_err_print(). + * + * \note API for this group of functions is described in the [error information module](@ref errors). + */ + +/** + * @defgroup errors Error information + * + * Structures and functions to allow error information processing. + * + * @{ + */ + +/** + * @typedef LY_ERR + * @brief libyang's error codes returned by the libyang functions. + */ +typedef enum { + LY_SUCCESS = 0, /**< no error, not set by functions, included just to complete #LY_ERR enumeration */ + LY_EMEM, /**< Memory allocation failure */ + LY_ESYS, /**< System call failure */ + LY_EINVAL, /**< Invalid value */ + LY_EEXIST, /**< Item already exists */ + LY_ENOTFOUND, /**< Item does not exists */ + LY_EINT, /**< Internal error */ + LY_EVALID, /**< Validation failure */ + LY_EDENIED, /**< Operation is not allowed */ + LY_EINCOMPLETE, /**< The operation did not fail, but for some reason it was not possible to finish it completely. + According to the specific use case, the caller is usually supposed to perform the operation again. */ + LY_ERECOMPILE, /**< The operation did not fail, but requires context recompilation before it can be completed. + According to the specific use case, the caller should react appropriately. */ + LY_ENOT, /**< Negative result */ + LY_EOTHER, /**< Unknown error */ + + LY_EPLUGIN = 128/**< Error reported by a plugin - the highest bit in the first byte is set. + This value is used ORed with one of the other LY_ERR value and can be simply masked. */ +} LY_ERR; + +/** + * @ingroup log + * @typedef LY_VECODE + * @brief libyang's codes of validation error. Whenever ly_errno is set to LY_EVALID, the ly_vecode is also set + * to the appropriate LY_VECODE value. + */ +typedef enum { + LYVE_SUCCESS = 0, /**< no error */ + LYVE_SYNTAX, /**< generic syntax error */ + LYVE_SYNTAX_YANG, /**< YANG-related syntax error */ + LYVE_SYNTAX_YIN, /**< YIN-related syntax error */ + LYVE_REFERENCE, /**< invalid referencing or using an item */ + LYVE_XPATH, /**< invalid XPath expression */ + LYVE_SEMANTICS, /**< generic semantic error */ + LYVE_SYNTAX_XML, /**< XML-related syntax error */ + LYVE_SYNTAX_JSON, /**< JSON-related syntax error */ + LYVE_DATA, /**< YANG data does not reflect some of the module restrictions */ + + LYVE_OTHER /**< Unknown error */ +} LY_VECODE; + +/** + * @brief Libyang full error structure. + */ +struct ly_err_item { + LY_LOG_LEVEL level; /**< error (message) log level */ + LY_ERR err; /**< error code number */ + LY_VECODE vecode; /**< validation error code, if any */ + char *msg; /**< error message */ + char *data_path; /**< error data path related to the error, if any */ + char *schema_path; /**< error schema path related to the error, if any */ + uint64_t line; /**< input line the error occured on, if available */ + char *apptag; /**< error-app-tag, if any */ + struct ly_err_item *next; /**< next error item */ + struct ly_err_item *prev; /**< previous error item, points to the last item for the ifrst item */ +}; + +/** + * @brief Get human-readable error message for an error code. + * + * @param[in] err Error code. + * @return String error message. + */ +LIBYANG_API_DECL const char *ly_strerr(LY_ERR err); + +/** + * @brief Get human-readable error message for a validation error code. + * + * @param[in] vecode Validation error code. + * @return String error message. + */ +LIBYANG_API_DECL const char *ly_strvecode(LY_VECODE vecode); + +/** + * @brief Get the last (thread-specific) full logged error message. + * + * This function is useful for getting errors from functions that do not have any context accessible and includes + * any additional information such as the path or line where the error occurred. + * + * @return Last generated error message. + */ +LIBYANG_API_DECL const char *ly_last_logmsg(void); + +/** + * @brief Get the first (thread, context-specific) generated error structure. + * + * @param[in] ctx Relative context. + * @return First error structure, NULL if none available. + */ +LIBYANG_API_DECL const struct ly_err_item *ly_err_first(const struct ly_ctx *ctx); + +/** + * @brief Get the latest (thread, context-specific) generated error structure. + * + * @param[in] ctx Relative context. + * @return Last error structure, NULL if none available. + */ +LIBYANG_API_DECL const struct ly_err_item *ly_err_last(const struct ly_ctx *ctx); + +/** + * @brief Print the error structure as if just generated. + * + * @param[in] ctx Optional context to store the message in. + * @param[in] eitem Error item structure to print. + */ +LIBYANG_API_DECL void ly_err_print(const struct ly_ctx *ctx, const struct ly_err_item *eitem); + +/** + * @brief Free error structures from a context. + * + * If @p eitem is not set, free all the error structures. + * + * @param[in] ctx Relative context. + * @param[in] eitem Oldest error structure to remove, optional. + */ +LIBYANG_API_DECL void ly_err_clean(struct ly_ctx *ctx, struct ly_err_item *eitem); + +/** @} errors */ + +#ifdef __cplusplus +} +#endif + +#endif /* LY_LOG_H_ */ |