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author | John Turner <jturner.usa@gmail.com> | 2025-09-14 00:16:10 -0400 |
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committer | John Turner <jturner.usa@gmail.com> | 2025-09-14 00:16:10 -0400 |
commit | efcea3a80da7c4479d5fe168435ecc9fd06bdc72 (patch) | |
tree | 5cb0177e17b1b00a177f2e830e809f606334571b /doc/reference/error.adoc | |
download | sqlite-kv-bench-efcea3a80da7c4479d5fe168435ecc9fd06bdc72.tar.gz |
Squashed 'subprojects/boost-sqlite/' content from commit 3378e35
git-subtree-dir: subprojects/boost-sqlite
git-subtree-split: 3378e353705271e569cf4ba15c467b840a39798c
Diffstat (limited to 'doc/reference/error.adoc')
-rw-r--r-- | doc/reference/error.adoc | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/doc/reference/error.adoc b/doc/reference/error.adoc new file mode 100644 index 0000000..424c7dd --- /dev/null +++ b/doc/reference/error.adoc @@ -0,0 +1,91 @@ +== `sqlite/error.hpp` + +=== `sqlite_category` + +The sqlite_category is a `boost::system::error_category` to be used with sqlite errors. + +=== `error_info` + +The `error_info` class hold additional information about error conditions stored in an sqlite-allocate string. + +Contains an error message describing what happened. Not all error conditions are able to generate this extended information - those that +can't will have an empty error message. + +The `error_info` allocates memory from the sqlite pool and holds it. + +[source,cpp] +---- +struct error_info +{ + // Default constructor. + error_info() = default; + + // Initialization constructor. Copies the message into a newly create buffer. + error_info(core::string_view msg) noexcept; + // set the message by copy + void set_message(core::string_view msg); + + // Reset the buffer. If `c` is not null, its ownership is transferred into the error_info object. + void reset(char * c = nullptr); + + // Format a message into a newly allocated buffer. + cstring_ref format(cstring_ref fmt, ...); + // Format a message into the existing buffer. + cstring_ref snformat(cstring_ref fmt, ...); + /// reserve data in the buffer i.e. allocate + void reserve(std::size_t sz); + + // Get the allocated memory + std::size_t capacity() const; + + // Gets the error message. + cstring_ref message() const noexcept; + + // Release the underlying memory. It must be freed using `sqlite_free` later. + char * release(); + // Restores the message to its initial state. Does not release memory. + void clear() noexcept; + +}; +---- + +=== `error` + +The `error` class holds `error_info` and a `code` and can be used with https://www.boost.org/doc/libs/master/libs/system/doc/html/system.html#ref_boostsystemresult_hpp[`boost::system::result`]. + +[source,cpp] +---- +/** + * \brief An error containing both a code & optional message. + * \ingroup reference + * \details Contains an error . + */ +struct error +{ + // The code of the error. + int code; + // The additional information of the error + error_info info; + + // Create an error with code & message + error(int code, error_info info) ; + error(int code, core::string_view info); + error(system::error_code code, error_info info) // <1> + // Create an error with only a code. + explicit error(int code); + + error(system::error_code code); + // Create an empty error; + error() = default; + error(error && ) noexcept = default; +}; + +// For compatability with system::result; +void throw_exception_from_error( error const & e, boost::source_location const & loc ); + +template<typename T = void> +using result = system::result<T, error>; +---- +<1> If code.category() is not `sqlite_category`, the code will be set to `SQLITE_FAIL`. + + |