1use crate::block::Block;
2use crate::cache::Cache;
3use crate::cmp::{Cmp, DefaultCmp};
4use crate::filter;
5use crate::types::{share, Shared};
6
7use std::default::Default;
8use std::sync::Arc;
9
10const KB: usize = 1 << 10;
11const MB: usize = KB * KB;
12
13const BLOCK_MAX_SIZE: usize = 4 * KB;
14const BLOCK_CACHE_CAPACITY: usize = 8 * MB;
15const WRITE_BUFFER_SIZE: usize = 4 * MB;
16const DEFAULT_BITS_PER_KEY: u32 = 10; #[derive(Clone, Copy, PartialEq, Debug)]
19pub enum CompressionType {
20 CompressionNone = 0,
21 CompressionSnappy = 1,
22}
23
24pub fn int_to_compressiontype(i: u32) -> Option<CompressionType> {
25 match i {
26 0 => Some(CompressionType::CompressionNone),
27 1 => Some(CompressionType::CompressionSnappy),
28 _ => None,
29 }
30}
31
32#[derive(Clone)]
35pub struct Options {
36 pub cmp: Arc<Box<dyn Cmp>>,
37 pub write_buffer_size: usize,
38 pub block_cache: Shared<Cache<Block>>,
39 pub block_size: usize,
40 pub block_restart_interval: usize,
41 pub compression_type: CompressionType,
42 pub filter_policy: filter::BoxedFilterPolicy,
43}
44
45impl Options {
46 pub fn with_cache_capacity(mut self, capacity: usize) -> Options {
50 self.block_cache = share(Cache::new(capacity));
51 self
52 }
53}
54
55impl Default for Options {
56 fn default() -> Options {
57 Options {
58 cmp: Arc::new(Box::new(DefaultCmp)),
59 write_buffer_size: WRITE_BUFFER_SIZE,
60 block_cache: share(Cache::new(BLOCK_CACHE_CAPACITY / BLOCK_MAX_SIZE)),
62 block_size: BLOCK_MAX_SIZE,
63 block_restart_interval: 16,
64 compression_type: CompressionType::CompressionNone,
65 filter_policy: Arc::new(Box::new(filter::BloomPolicy::new(DEFAULT_BITS_PER_KEY))),
66 }
67 }
68}
69