1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173

use libc::c_uint;

use ffi::*;

bitflags! {
    #[doc="Environment options."]
    #[derive(Default)]
    pub struct 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 reserved 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."]
    #[derive(Default)]
    pub struct 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."]
    #[derive(Default)]
    pub struct 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;
    }
}