use libc::c_uint; bitflags! { #[doc="Environment Options"] #[deriving(Show)] 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 MDB_FIXEDMAP = 0x01, #[doc="By default, LMDB creates its environment in a directory whose"] #[doc="pathname is given in `path`, and creates its data and lock files"] #[doc="under that directory. With this option, `path` is used as-is for"] #[doc="the database main data file. The database lock file is the `path`"] #[doc="with `-lock` appended."] const MDB_NOSUBDIR = 0x4000, #[doc="Use a writeable memory map unless `MDB_RDONLY` 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 `MDB_WRITEMAP` on the same environment do not cooperate"] #[doc="well."] const MDB_WRITEMAP = 0x80000, #[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 MDB_RDONLY = 0x20000, #[doc="Flush system buffers to disk only once per transaction, omit the"] #[doc="metadata flush. Defer that until the system flushes files to disk,"] #[doc="or next non-`MDB_RDONLY` commit or #mdb_env_sync(). This optimization"] #[doc="maintains database integrity, but a system crash may undo the last"] #[doc="committed transaction. I.e. it preserves the ACI (atomicity,"] #[doc="consistency, isolation) but not D (durability) database property."] #[doc="\n\nThis flag may be changed at any time using `Environment::set_flags`."] const MDB_NOMETASYNC = 0x40000, #[doc="Don't flush system buffers to disk when committing a transaction."] #[doc="This optimization means a system crash can corrupt the database or"] #[doc="lose the last transactions if buffers are not yet flushed to disk."] #[doc="The risk is governed by how often the system flushes dirty buffers"] #[doc="to disk and how often `Environment::sync` is called. However, if the"] #[doc="filesystem preserves write order and the `MDB_WRITEMAP` flag is not"] #[doc="used, transactions exhibit ACI (atomicity, consistency, isolation)"] #[doc="properties and only lose D (durability). I.e. database integrity"] #[doc="is maintained, but a system crash may undo the final transactions."] #[doc="Note that (`MDB_NOSYNC | MDB_WRITEMAP`) leaves the system with no"] #[doc="hint for when to write transactions to disk, unless `Environment::sync`"] #[doc="is called. (`MDB_MAPASYNC | MDB_WRITEMAP`) may be preferable."] #[doc="\n\nThis flag may be changed at any time using `Environment::set_flags`."] const MDB_NOSYNC = 0x10000, #[doc="When using `MDB_WRITEMAP`, use asynchronous flushes to disk."] #[doc="As with `MDB_NOSYNC`, a system crash can then corrupt the"] #[doc="database or lose the last transactions. Calling `Environment::sync`"] #[doc="ensures on-disk database integrity until next commit."] #[doc="\n\nThis flag may be changed at any time using `Environment::set_flags`."] const MDB_MAPASYNC = 0x100000, #[doc="Don't use Thread-Local Storage. Tie reader locktable slots to"] #[doc="transaction objects instead of to threads. I.e. `RoTransaction::reset` keeps"] #[doc="the slot reseved for the transaction object. A thread may use parallel"] #[doc="read-only transactions. A read-only transaction may span threads if"] #[doc="the user synchronizes its use. Applications that multiplex many"] #[doc="user threads over individual OS threads need this option. Such an"] #[doc="application must also serialize the write transactions in an OS"] #[doc="thread, since LMDB's write locking is unaware of the user threads."] const MDB_NOTLS = 0x200000, #[doc="Don't do any locking. If concurrent access is anticipated, the"] #[doc="caller must manage all concurrency themself. For proper operation"] #[doc="the caller must enforce single-writer semantics, and must ensure"] #[doc="that no readers are using old transactions while a writer is"] #[doc="active. The simplest approach is to use an exclusive lock so that"] #[doc="no readers may be active at all when a writer begins."] const MDB_NOLOCK = 0x400000, #[doc="Turn off readahead. Most operating systems perform readahead on"] #[doc="read requests by default. This option turns it off if the OS"] #[doc="supports it. Turning it off may help random read performance"] #[doc="when the DB is larger than RAM and system RAM is full."] #[doc="The option is not implemented on Windows."] const MDB_NORDAHEAD = 0x800000, #[doc="Don't initialize malloc'd memory before writing to unused spaces"] #[doc="in the data file. By default, memory for pages written to the data"] #[doc="file is obtained using malloc. While these pages may be reused in"] #[doc="subsequent transactions, freshly malloc'd pages will be initialized"] #[doc="to zeroes before use. This avoids persisting leftover data from other"] #[doc="code (that used the heap and subsequently freed the memory) into the"] #[doc="data file. Note that many other system libraries may allocate"] #[doc="and free memory from the heap for arbitrary uses. E.g., stdio may"] #[doc="use the heap for file I/O buffers. This initialization step has a"] #[doc="modest performance cost so some applications may want to disable"] #[doc="it using this flag. This option can be a problem for applications"] #[doc="which handle sensitive data like passwords, and it makes memory"] #[doc="checkers like Valgrind noisy. This flag is not needed with `MDB_WRITEMAP`,"] #[doc="which writes directly to the mmap instead of using malloc for pages. The"] #[doc="initialization is also skipped if `MDB_RESERVE` is used; the"] #[doc="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 MDB_NOMEMINIT = 0x1000000, } } bitflags! { #[doc="Database Options"] #[deriving(Show)] flags DatabaseFlags: c_uint { #[doc="Keys are strings to be compared in reverse order, from the end"] #[doc="of the strings to the beginning. By default, Keys are treated as strings and"] #[doc="compared from beginning to end."] const MDB_REVERSEKEY = 0x02, #[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 MDB_DUPSORT = 0x04, #[doc="Keys are binary integers in native byte order. Setting this option"] #[doc="requires all keys to be the same size, typically sizeof(int)"] #[doc="or sizeof(size_t)."] const MDB_INTEGERKEY = 0x08, #[doc="This flag may only be used in combination with `MDB_DUPSORT`. This option"] #[doc="tells the library that the data items for this database are all the same"] #[doc="size, which allows further optimizations in storage and retrieval. When"] #[doc="all data items are the same size, the `MDB_GET_MULTIPLE` and `MDB_NEXT_MULTIPLE`"] #[doc="cursor operations may be used to retrieve multiple items at once."] const MDB_DUPFIXED = 0x10, #[doc="This option specifies that duplicate data items are also integers, and"] #[doc="should be sorted as such."] const MDB_INTEGERDUP = 0x20, #[doc="This option specifies that duplicate data items should be compared as"] #[doc="strings in reverse order."] const MDB_REVERSEDUP = 0x40, } } bitflags! { #[doc="Write Options"] #[deriving(Show)] 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 (`MDB_DUPSORT`)."] const MDB_NOOVERWRITE = 0x10, #[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 `MDB_DUPSORT`."] #[doc="The function will return `LmdbError::KeyExist` if the item already appears in the"] #[doc="database."] const MDB_NODUPDATA = 0x20, #[doc="For `Cursor::put`. Replace the item at the current cursor position."] #[doc="The key parameter must match the current position. If using"] #[doc="sorted duplicates (`MDB_DUPSORT`) the data item must still sort into the"] #[doc="same position. This is intended to be used when the new data is the same"] #[doc="size as the old. Otherwise it will simply perform a delete of the old"] #[doc="record followed by an insert."] const MDB_CURRENT = 0x40, #[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 MDB_APPEND = 0x20000, #[doc="Same as `MDB_APPEND`, but for sorted dup data."] const MDB_APPENDDUP = 0x40000, } }