mysql-handler 0.1.1

Rust bindings for the MySQL handler
Documentation
// Copyright (C) 2026 ren-yamanashi
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License, version 2.0,
// as published by the Free Software Foundation.
//
// This program is designed to work with certain software (including
// but not limited to OpenSSL) that is licensed under separate terms,
// as designated in a particular file or component or in included license
// documentation. The authors of this program hereby grant you an additional
// permission to link the program and your derivative works with the
// separately licensed software that they have either included with
// the program or referenced in the documentation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, see <https://www.gnu.org/licenses/>.

//! Raw FFI bindings: MySQL handler constants and opaque C++ types

#[allow(non_upper_case_globals, non_camel_case_types, non_snake_case)]
#[allow(missing_docs, unreachable_pub, missing_debug_implementations)]
#[allow(clippy::all, clippy::pedantic)]
mod generated {
    include!("sys_bindings.rs");
}

pub use generated::*;

// Hand-written as `u64` because `Table_flags` is `unsigned long long` upstream
// but bindgen's default macro type would render these as `i64`.

/// `HA_BINLOG_ROW_CAPABLE` from `sql/handler.h`
pub const HA_BINLOG_ROW_CAPABLE: u64 = 1 << 34;

/// `HA_BINLOG_STMT_CAPABLE` from `sql/handler.h`
pub const HA_BINLOG_STMT_CAPABLE: u64 = 1 << 35;

/// `HTON_CAN_RECREATE` from `sql/handler.h`: the engine implements `TRUNCATE`
/// by recreating the table. This is the flag the zero-config handlerton sets,
/// so it backs [`HtonFlags::CAN_RECREATE`]. Hand-written as `u32` because
/// `sql/handler.h` is not a bindgen input; `shim/binding.cc` static-asserts
/// the value to catch upstream drift.
///
/// [`HtonFlags::CAN_RECREATE`]: crate::hton::HtonFlags::CAN_RECREATE
pub const HTON_CAN_RECREATE: u32 = 1 << 2;

/// `HA_READ_NEXT` from `sql/handler.h`: index supports forward
/// `index_next`.
pub const HA_READ_NEXT: u32 = 1;

/// `HA_READ_PREV` from `sql/handler.h`: index supports backward
/// `index_prev`.
pub const HA_READ_PREV: u32 = 2;

/// `HA_READ_ORDER` from `sql/handler.h`: index reads return rows in key
/// order (the optimizer skips a server-side sort).
pub const HA_READ_ORDER: u32 = 4;

/// `HA_READ_RANGE` from `sql/handler.h`: index supports `read_range_first`
/// / `read_range_next`.
pub const HA_READ_RANGE: u32 = 8;

/// Opaque C++ `RustHandlerBase` from `shim/binding.hpp`
#[repr(C)]
#[derive(Debug)]
pub struct RustHandlerBase([u8; 0]);

/// Opaque MySQL `TABLE`
#[repr(C)]
#[derive(Debug)]
pub struct TABLE([u8; 0]);

/// Opaque MySQL `TABLE_SHARE`
#[repr(C)]
#[derive(Debug)]
pub struct TABLE_SHARE([u8; 0]);

/// Opaque MySQL `THD` (thread handle)
#[repr(C)]
#[derive(Debug)]
pub struct THD([u8; 0]);

/// Opaque MySQL `XID` (X/Open distributed-transaction identifier)
#[repr(C)]
#[derive(Debug)]
pub struct XID([u8; 0]);

/// Opaque MySQL data-dictionary `dd::Table`
#[repr(C)]
#[derive(Debug)]
pub struct DdTable([u8; 0]);

/// Opaque MySQL data-dictionary `dd::Column`
#[repr(C)]
#[derive(Debug)]
pub struct DdColumn([u8; 0]);

/// Opaque MySQL data-dictionary `dd::Index`
#[repr(C)]
#[derive(Debug)]
pub struct DdIndex([u8; 0]);

/// Opaque MySQL data-dictionary `dd::Index_element` (key part)
#[repr(C)]
#[derive(Debug)]
pub struct DdIndexElement([u8; 0]);

/// Opaque MySQL `HA_CREATE_INFO`
#[allow(non_camel_case_types)]
#[repr(C)]
#[derive(Debug)]
pub struct HA_CREATE_INFO([u8; 0]);

/// Opaque MySQL `KEY` (index descriptor)
#[allow(non_camel_case_types)]
#[repr(C)]
#[derive(Debug)]
pub struct KEY([u8; 0]);

/// Opaque MySQL `List<Create_field>` (C++ template instantiation)
#[repr(C)]
#[derive(Debug)]
pub struct ListCreateField([u8; 0]);

/// Opaque MySQL `Rows_mysql` (bulk-load row batch)
#[repr(C)]
#[derive(Debug)]
pub struct RowsMysql([u8; 0]);

/// Opaque MySQL `Bulk_load::Stat_callbacks` (bulk-load progress callbacks)
#[repr(C)]
#[derive(Debug)]
pub struct BulkLoadStatCallbacks([u8; 0]);

/// Opaque MySQL `String` (a full-text query string, among other uses)
#[repr(C)]
#[derive(Debug)]
pub struct MysqlString([u8; 0]);

/// Opaque MySQL `Ft_hints` (full-text search hints)
#[repr(C)]
#[derive(Debug)]
pub struct FtHints([u8; 0]);

/// Opaque MySQL `RANGE_SEQ_IF` (multi-range read range-sequence interface)
#[repr(C)]
#[derive(Debug)]
pub struct RangeSeqIf([u8; 0]);

/// Opaque MySQL `Cost_estimate` (optimizer cost accumulator)
#[repr(C)]
#[derive(Debug)]
pub struct CostEstimate([u8; 0]);

/// Opaque MySQL `HANDLER_BUFFER` (caller-owned multi-range read scratch buffer)
#[repr(C)]
#[derive(Debug)]
pub struct HandlerBuffer([u8; 0]);

/// Opaque MySQL `Field` (one table column's metadata and value accessors)
#[repr(C)]
#[derive(Debug)]
pub struct Field([u8; 0]);

/// Opaque MySQL `Alter_inplace_info` (in-place `ALTER TABLE` change descriptor)
#[repr(C)]
#[derive(Debug)]
pub struct AlterInplaceInfo([u8; 0]);

/// Opaque MySQL `HA_CHECK_OPT` (options for `CHECK` / `REPAIR` / `ANALYZE` etc.)
#[repr(C)]
#[derive(Debug)]
pub struct HaCheckOpt([u8; 0]);

/// Opaque MySQL `MDL_key` (metadata-lock key identifying a database object)
#[repr(C)]
#[derive(Debug)]
pub struct MdlKey([u8; 0]);

/// Opaque MySQL `dd::Tablespace` (data-dictionary tablespace object)
#[repr(C)]
#[derive(Debug)]
pub struct DdTablespace([u8; 0]);

/// Opaque MySQL `st_alter_tablespace` (legacy ALTER TABLESPACE descriptor)
#[repr(C)]
#[derive(Debug)]
pub struct StAlterTablespace([u8; 0]);

/// Opaque MySQL `sdi_key_t` (SDI key identifying a dictionary object)
#[repr(C)]
#[derive(Debug)]
pub struct SdiKey([u8; 0]);

/// Opaque MySQL `sdi_vector_t` (collection of SDI keys filled by `sdi_get_keys`)
#[repr(C)]
#[derive(Debug)]
pub struct SdiVector([u8; 0]);

/// Opaque MySQL `Json_dom` (JSON DOM node for log-info collection)
#[repr(C)]
#[derive(Debug)]
pub struct JsonDom([u8; 0]);

/// Opaque MySQL `Ha_fk_column_type` (foreign-key column type descriptor)
#[repr(C)]
#[derive(Debug)]
pub struct HaFkColumnType([u8; 0]);

/// Opaque MySQL `LEX` (parsed-statement descriptor used by the optimizer)
#[repr(C)]
#[derive(Debug)]
pub struct Lex([u8; 0]);

/// Opaque MySQL `JOIN` (join-plan descriptor handed to cost-comparison hooks)
#[repr(C)]
#[derive(Debug)]
pub struct Join([u8; 0]);

/// Opaque MySQL `JoinHypergraph` (hypergraph used by the new join optimizer)
#[repr(C)]
#[derive(Debug)]
pub struct JoinHypergraph([u8; 0]);

/// Opaque MySQL `AccessPath` (an execution-plan node from the join optimizer)
#[repr(C)]
#[derive(Debug)]
pub struct AccessPath([u8; 0]);

/// Opaque MySQL `Ha_clone_cbk` (data-transfer callback object used by clone)
#[repr(C)]
#[derive(Debug)]
pub struct HaCloneCbk([u8; 0]);

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn ha_err_end_of_file_is_137() {
        assert_eq!(HA_ERR_END_OF_FILE, 137);
    }

    #[test]
    fn ha_binlog_stmt_capable_bit() {
        assert_eq!(HA_BINLOG_STMT_CAPABLE, 1u64 << 35);
    }

    #[test]
    fn hton_can_recreate_bit() {
        assert_eq!(HTON_CAN_RECREATE, 1u32 << 2);
    }
}