Cargo Features
lmdb-master3-sys has no features set by default.
[dependencies]
lmdb-master3-sys = { version = "0.2.4", features = ["posix-sem", "mdb_idl_logn_8", "mdb_idl_logn_11", "mdb_idl_logn_14", "mdb_idl_logn_16", "longer-keys", "bindgen"] }- asan fuzzer fuzzer-no-link posix-sem
- mdb_idl_logn_8
-
These features configure the MDB_IDL_LOGN macro, which determines the size of the free and dirty page lists (and thus the amount of memory allocated when opening an LMDB environment in read-write mode).
Each feature defines MDB_IDL_LOGN as the value in the name of the feature. That means these features are mutually exclusive, and you must not specify more than one at the same time (or the crate will fail to compile).
For more information on the motivation for these features (and their effect), see https://github.com/mozilla/lmdb/pull/2.
- mdb_idl_logn_9 mdb_idl_logn_10 mdb_idl_logn_11
- mdb_idl_logn_12 mdb_idl_logn_13 mdb_idl_logn_14
- mdb_idl_logn_15 mdb_idl_logn_16
- longer-keys
-
Setting this enables you to use keys longer than 511 bytes. The exact limit is computed by LMDB at compile time. You can find the exact value by calling Env::max_key_size(). This value varies by architecture.
Example max key sizes:
- Apple M1 (ARM64): 8126 bytes
- Apple Intel (AMD64): 1982 bytes
- Linux Intel (AMD64): 1982 bytes
Setting this also enables you to use values larger than 511 bytes when using a Database with the DatabaseFlags::DUP_SORT flag.
This builds LMDB with the -DMDB_MAXKEYSIZE=0 option.
Note: If you are moving database files between architectures then your longest stored key must fit within the smallest limit of all architectures used. For example, if you are moving databases between Apple M1 and Apple Intel computers then you need to keep your keys within the smaller 1982 byte limit.
Features from optional dependencies
- bindgen build implicit feature
-
Enables bindgen ^0.70.1
bindgen:
Automatically generates Rust FFI bindings to C and C++ libraries