Options class abstract
Options to control the behavior of a database (passed to LevelDB.open)
Constructors
- Options.byDefault({Comparator? comparator, FilterPolicy? filterPolicy, bool createIfMissing = false, bool errorIfExists = false, bool paranoidChecks = false, Env? env, int writeBufferSize = 4 * 1024 * 1024, int maxOpenFiles = 1000, Cache? blockCache, int blockSize = 4 * 1024, int blockRestartInterval = 16, int maxFileSize = 2 * 1024 * 1024, CompressionType compressionType = CompressionType.snappy})
-
Create an Options object with default values for all fields.
factory
Properties
- blockCache → Cache?
-
Control over blocks (user data is stored in a set of blocks, and
a block is the unit of reading from disk).
no setter
- blockRestartInterval ↔ int
-
Number of keys between restart points for delta encoding of keys.
This parameter can be changed dynamically. Most clients should
leave this parameter alone.
getter/setter pair
- blockSize ↔ int
-
Approximate size of user data packed per block. Note that the
block size specified here corresponds to uncompressed data. The
actual size of the unit read from disk may be smaller if
compression is enabled. This parameter can be changed dynamically.
getter/setter pair
- comparator → Comparator?
-
Comparator used to define the order of keys in the table.
Default: a comparator that uses lexicographic byte-wise ordering
no setter
- compressionType → CompressionType
-
Compress blocks using the specified compression algorithm. This
parameter can be changed dynamically.
no setter
- createIfMissing → bool
-
If true, the database will be created if it is missing.
no setter
- env → Env?
-
Use the specified object to interact with the environment,
e.g. to read/write files, schedule background work, etc.
Default:
Env.byDefaultno setter - errorIfExists → bool
-
If true, an error is raised if the database already exists.
no setter
- filterPolicy → FilterPolicy?
-
If non-null, use the specified filter policy to reduce disk reads.
Many applications will benefit from passing the result of
FilterPolicy.bloom()here.no setter - hashCode → int
-
The hash code for this object.
no setteroverride
- maxFileSize → int
-
Leveldb will write up to this amount of bytes to a file before
switching to a new one.
Most clients should leave this parameter alone. However if your
filesystem is more efficient with larger files, you could
consider increasing the value. The downside will be longer
compactions and hence longer latency/performance hiccups.
Another reason to increase this parameter might be when you are
initially populating a large database.
no setter
- maxOpenFiles → int
-
Number of open files that can be used by the DB. You may need to
increase this if your database has a large working set (budget
one open file per 2MB of working set).
no setter
- paranoidChecks → bool
-
If true, the implementation will do aggressive checking of the
data it is processing and will stop early if it detects any
errors. This may have unforeseen ramifications: for example, a
corruption of one DB entry may cause a large number of entries to
become unreadable or for the entire DB to become unopenable.
no setter
-
ptr
→ Pointer<
NativeType> -
no setterinherited
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
- writeBufferSize → int
-
Amount of data to build up in memory (backed by an unsorted log
on disk) before converting to a sorted on-disk file.
no setter
Methods
-
dispose(
) → void -
inherited
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
toString(
) → String -
A string representation of this object.
override
Operators
-
operator ==(
Object o) → bool -
The equality operator.
override