use libc::c_uint; use ffi::*; bitflags! { #[doc="Environment Options"] flags EnvironmentFlags: c_uint { #[doc="Use a fixed address for the mmap region. This flag must be specified"] #[doc="when creating the environment, and is stored persistently in the environment."] #[doc="If successful, the memory map will always reside at the same virtual address"] #[doc="and pointers used to reference data items in the database will be constant"] #[doc="across multiple invocations. This option may not always work, depending on"] #[doc="how the operating system has allocated memory to shared libraries and other uses."] #[doc="The feature is highly experimental."] const FIXED_MAP = MDB_FIXEDMAP, #[doc="By default, LMDB creates its environment in a directory whose pathname is given in"] #[doc="`path`, and creates its data and lock files under that directory. With this option,"] #[doc="`path` is used as-is for the database main data file. The database lock file is the"] #[doc="`path` with `-lock` appended."] const NO_SUB_DIR = MDB_NOSUBDIR, #[doc="Use a writeable memory map unless `READ_ONLY` is set. This is faster and uses"] #[doc="fewer mallocs, but loses protection from application bugs like wild pointer writes"] #[doc="and other bad updates into the database. Incompatible with nested transactions."] #[doc="Processes with and without `WRITE_MAP` on the same environment do not cooperate"] #[doc="well."] const WRITE_MAP = MDB_WRITEMAP, #[doc="Open the environment in read-only mode. No write operations will be allowed."] #[doc="When opening an environment, LMDB will still modify the lock file - except on"] #[doc="read-only filesystems, where LMDB does not use locks."] const READ_ONLY = MDB_RDONLY, #[doc="Flush system buffers to disk only once per transaction, omit the metadata flush."] #[doc="Defer that until the system flushes files to disk, or next non-`READ_ONLY` commit"] #[doc="or `Environment::sync`. This optimization maintains database integrity, but a"] #[doc="system crash may undo the last committed transaction. I.e. it preserves the ACI"] #[doc="(atomicity, consistency, isolation) but not D (durability) database property."] #[doc="\n\nThis flag may be changed at any time using `Environment::set_flags`."] const NO_META_SYNC = MDB_NOMETASYNC, #[doc="Don't flush system buffers to disk when committing a transaction. This optimization"] #[doc="means a system crash can corrupt the database or lose the last transactions if"] #[doc="buffers are not yet flushed to disk. The risk is governed by how often the system"] #[doc="flushes dirty buffers to disk and how often `Environment::sync` is called. However,"] #[doc="if the filesystem preserves write order and the `WRITE_MAP` flag is not used,"] #[doc="transactions exhibit ACI (atomicity, consistency, isolation) properties and only"] #[doc="lose D (durability). I.e. database integrity is maintained, but a system"] #[doc="crash may undo the final transactions. Note that (`NO_SYNC | WRITE_MAP`) leaves the"] #[doc="system with no hint for when to write transactions to disk, unless"] #[doc="`Environment::sync` is called. (`MAP_ASYNC | WRITE_MAP`) may be preferable."] #[doc="\n\nThis flag may be changed at any time using `Environment::set_flags`."] const NO_SYNC = MDB_NOSYNC, #[doc="When using `WRITE_MAP`, use asynchronous flushes to disk. As with `NO_SYNC`, a"] #[doc="system crash can then corrupt the database or lose the last transactions. Calling"] #[doc="`Environment::sync` ensures on-disk database integrity until next commit."] #[doc="\n\nThis flag may be changed at any time using `Environment::set_flags`."] const MAP_ASYNC = MDB_MAPASYNC, #[doc="Don't use thread-local storage. Tie reader locktable slots to transaction objects"] #[doc="instead of to threads. I.e. `RoTransaction::reset` keeps the slot reseved for the"] #[doc="transaction object. A thread may use parallel read-only transactions. A read-only"] #[doc="transaction may span threads if the user synchronizes its use. Applications that"] #[doc="multiplex many the user synchronizes its use. Applications that multiplex many user"] #[doc="threads over individual OS threads need this option. Such an application must also"] #[doc="serialize the write transactions in an OS thread, since LMDB's write locking is"] #[doc="unaware of the user threads."] const NO_TLS = MDB_NOTLS, #[doc="Do not do any locking. If concurrent access is anticipated, the caller must manage"] #[doc="all concurrency themself. For proper operation the caller must enforce"] #[doc="single-writer semantics, and must ensure that no readers are using old"] #[doc="transactions while a writer is active. The simplest approach is to use an exclusive"] #[doc="lock so that no readers may be active at all when a writer begins."] const NO_LOCK = MDB_NOLOCK, #[doc="Turn off readahead. Most operating systems perform readahead on read requests by"] #[doc="default. This option turns it off if the OS supports it. Turning it off may help"] #[doc="random read performance when the DB is larger than RAM and system RAM is full."] #[doc="The option is not implemented on Windows."] const NO_READAHEAD = MDB_NORDAHEAD, #[doc="Do not initialize malloc'd memory before writing to unused spaces in the data file."] #[doc="By default, memory for pages written to the data file is obtained using malloc."] #[doc="While these pages may be reused in subsequent transactions, freshly malloc'd pages"] #[doc="will be initialized to zeroes before use. This avoids persisting leftover data from"] #[doc="other code (that used the heap and subsequently freed the memory) into the data"] #[doc="file. Note that many other system libraries may allocate and free memory from the"] #[doc="heap for arbitrary uses. E.g., stdio may use the heap for file I/O buffers. This"] #[doc="initialization step has a modest performance cost so some applications may want to"] #[doc="disable it using this flag. This option can be a problem for applications which"] #[doc="handle sensitive data like passwords, and it makes memory checkers like Valgrind"] #[doc="noisy. This flag is not needed with `WRITE_MAP`, which writes directly to the mmap"] #[doc="instead of using malloc for pages. The initialization is also skipped if writing"] #[doc="with reserve; the caller is expected to overwrite all of the memory that was"] #[doc="reserved in that case."] #[doc="\n\nThis flag may be changed at any time using `Environment::set_flags`."] const NO_MEM_INIT = MDB_NOMEMINIT, } } bitflags! { #[doc="Database Options"] flags DatabaseFlags: c_uint { #[doc="Keys are strings to be compared in reverse order, from the end of the strings"] #[doc="to the beginning. By default, Keys are treated as strings and compared from"] #[doc="beginning to end."] const REVERSE_KEY = MDB_REVERSEKEY, #[doc="Duplicate keys may be used in the database. (Or, from another perspective,"] #[doc="keys may have multiple data items, stored in sorted order.) By default"] #[doc="keys must be unique and may have only a single data item."] const DUP_SORT = MDB_DUPSORT, #[doc="Keys are binary integers in native byte order. Setting this option requires all"] #[doc="keys to be the same size, typically 32 or 64 bits."] const INTEGER_KEY = MDB_INTEGERKEY, #[doc="This flag may only be used in combination with `DUP_SORT`. This option tells"] #[doc="the library that the data items for this database are all the same size, which"] #[doc="allows further optimizations in storage and retrieval. When all data items are"] #[doc="the same size, the `GET_MULTIPLE` and `NEXT_MULTIPLE` cursor operations may be"] #[doc="used to retrieve multiple items at once."] const DUP_FIXED = MDB_DUPFIXED, #[doc="This option specifies that duplicate data items are also integers, and"] #[doc="should be sorted as such."] const INTEGER_DUP = MDB_INTEGERDUP, #[doc="This option specifies that duplicate data items should be compared as strings"] #[doc="in reverse order."] const REVERSE_DUP = MDB_REVERSEDUP, } } bitflags! { #[doc="Write Options"] flags WriteFlags: c_uint { #[doc="Insert the new item only if the key does not already appear in the database."] #[doc="The function will return `LmdbError::KeyExist` if the key already appears in the"] #[doc="database, even if the database supports duplicates (`DUP_SORT`)."] const NO_OVERWRITE = MDB_NOOVERWRITE, #[doc="Insert the new item only if it does not already appear in the database."] #[doc="This flag may only be specified if the database was opened with `DUP_SORT`."] #[doc="The function will return `LmdbError::KeyExist` if the item already appears in the"] #[doc="database."] const NO_DUP_DATA = MDB_NODUPDATA, #[doc="For `Cursor::put`. Replace the item at the current cursor position. The key"] #[doc="parameter must match the current position. If using sorted duplicates (`DUP_SORT`)"] #[doc="the data item must still sort into the same position. This is intended to be used"] #[doc="when the new data is the same size as the old. Otherwise it will simply perform a"] #[doc="delete of the old record followed by an insert."] const CURRENT = MDB_CURRENT, #[doc="Append the given item to the end of the database. No key comparisons are performed."] #[doc="This option allows fast bulk loading when keys are already known to be in the"] #[doc="correct order. Loading unsorted keys with this flag will cause data corruption."] const APPEND = MDB_APPEND, #[doc="Same as `APPEND`, but for sorted dup data."] const APPEND_DUP = MDB_APPENDDUP, } }