Struct amadeus_streaming::Top [−][src]
pub struct Top<A, C: New> { /* fields omitted */ }
Expand description
This probabilistic data structure tracks the n
top keys given a stream of (key,value)
tuples, ordered by the sum of the values for each key (the “aggregated value”). It uses only O(n)
space.
Its implementation is two parts:
- a doubly linked hashmap, mapping the top
n
keys to their aggregated values, and ordered by their aggregated values. This is used to keep a more precise track of the aggregated value of the topn
keys, and reduce collisions in the count-min sketch. - a count-min sketch to track all of the keys outside the top
n
. This data structure is also known as a counting Bloom filter. It uses conservative updating for increased accuracy.
The algorithm is as follows:
while a key and value from the input stream arrive:
if H[key] exists
increment aggregated value associated with H[key]
elsif number of items in H < k
put H[key] into map with its associated value
else
add C[key] into the count-min sketch with its associated value
if aggregated value associated with C[key] is > the lowest aggregated value in H
move the lowest key and value from H into C
move C[key] and value from C into H
endwhile
See An Improved Data Stream Summary: The Count-Min Sketch and its Applications and New Directions in Traffic Measurement and Accounting for background on the count-min sketch with conservative updating.
Implementations
impl<A: Hash + Eq + Clone, C: Ord + New + for<'a> UnionAssign<&'a C> + Intersect> Top<A, C>
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impl<A: Hash + Eq + Clone, C: Ord + New + for<'a> UnionAssign<&'a C> + Intersect> Top<A, C>
[src]pub fn new(
n: usize,
probability: f64,
tolerance: f64,
config: <C as New>::Config
) -> Self
[src]
pub fn new(
n: usize,
probability: f64,
tolerance: f64,
config: <C as New>::Config
) -> Self
[src]Create an empty Top
data structure with the specified n
capacity.
pub fn push<V: ?Sized>(&mut self, item: A, value: &V) where
C: for<'a> AddAssign<&'a V> + IntersectPlusUnionIsPlus,
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pub fn push<V: ?Sized>(&mut self, item: A, value: &V) where
C: for<'a> AddAssign<&'a V> + IntersectPlusUnionIsPlus,
[src]“Visit” an element.
Trait Implementations
impl<A: Hash + Eq + Clone, C: Ord + New + Clone + for<'a> AddAssign<&'a C> + for<'a> UnionAssign<&'a C> + Intersect + IntersectPlusUnionIsPlus> Add<Top<A, C>> for Top<A, C>
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impl<A: Hash + Eq + Clone, C: Ord + New + Clone + for<'a> AddAssign<&'a C> + for<'a> UnionAssign<&'a C> + Intersect + IntersectPlusUnionIsPlus> Add<Top<A, C>> for Top<A, C>
[src]impl<A: Hash + Eq + Clone, C: Ord + New + Clone + for<'a> AddAssign<&'a C> + for<'a> UnionAssign<&'a C> + Intersect + IntersectPlusUnionIsPlus> AddAssign<Top<A, C>> for Top<A, C>
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impl<A: Hash + Eq + Clone, C: Ord + New + Clone + for<'a> AddAssign<&'a C> + for<'a> UnionAssign<&'a C> + Intersect + IntersectPlusUnionIsPlus> AddAssign<Top<A, C>> for Top<A, C>
[src]fn add_assign(&mut self, other: Self)
[src]
fn add_assign(&mut self, other: Self)
[src]Performs the +=
operation. Read more
impl<A: Hash + Eq + Clone + Debug, C: Ord + New + Clone + for<'a> UnionAssign<&'a C> + Intersect + Debug> Debug for Top<A, C>
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impl<A: Hash + Eq + Clone + Debug, C: Ord + New + Clone + for<'a> UnionAssign<&'a C> + Intersect + Debug> Debug for Top<A, C>
[src]impl<'de, A, C: New> Deserialize<'de> for Top<A, C> where
A: Hash + Eq + Deserialize<'de>,
C: Deserialize<'de>,
<C as New>::Config: Deserialize<'de>,
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impl<'de, A, C: New> Deserialize<'de> for Top<A, C> where
A: Hash + Eq + Deserialize<'de>,
C: Deserialize<'de>,
<C as New>::Config: Deserialize<'de>,
[src]fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where
__D: Deserializer<'de>,
[src]
fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where
__D: Deserializer<'de>,
[src]Deserialize this value from the given Serde deserializer. Read more
Auto Trait Implementations
impl<A, C> RefUnwindSafe for Top<A, C> where
A: RefUnwindSafe,
C: RefUnwindSafe,
<C as New>::Config: RefUnwindSafe,
A: RefUnwindSafe,
C: RefUnwindSafe,
<C as New>::Config: RefUnwindSafe,
impl<A, C> Send for Top<A, C> where
A: Send,
C: Send,
<C as New>::Config: Send,
A: Send,
C: Send,
<C as New>::Config: Send,
impl<A, C> Sync for Top<A, C> where
A: Sync,
C: Sync,
<C as New>::Config: Sync,
A: Sync,
C: Sync,
<C as New>::Config: Sync,
impl<A, C> Unpin for Top<A, C> where
A: Unpin,
C: Unpin,
<C as New>::Config: Unpin,
A: Unpin,
C: Unpin,
<C as New>::Config: Unpin,
impl<A, C> UnwindSafe for Top<A, C> where
A: UnwindSafe,
C: UnwindSafe,
<C as New>::Config: UnwindSafe,
A: UnwindSafe,
C: UnwindSafe,
<C as New>::Config: UnwindSafe,
Blanket Implementations
impl<T> BorrowMut<T> for T where
T: ?Sized,
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impl<T> BorrowMut<T> for T where
T: ?Sized,
[src]pub fn borrow_mut(&mut self) -> &mut T
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pub fn borrow_mut(&mut self) -> &mut T
[src]Mutably borrows from an owned value. Read more
impl<T> ToOwned for T where
T: Clone,
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impl<T> ToOwned for T where
T: Clone,
[src]type Owned = T
type Owned = T
The resulting type after obtaining ownership.
pub fn to_owned(&self) -> T
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pub fn to_owned(&self) -> T
[src]Creates owned data from borrowed data, usually by cloning. Read more
pub fn clone_into(&self, target: &mut T)
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pub fn clone_into(&self, target: &mut T)
[src]🔬 This is a nightly-only experimental API. (toowned_clone_into
)
recently added
Uses borrowed data to replace owned data, usually by cloning. Read more
impl<V, T> VZip<V> for T where
V: MultiLane<T>,
impl<V, T> VZip<V> for T where
V: MultiLane<T>,
pub fn vzip(self) -> V
impl<T> DeserializeOwned for T where
T: for<'de> Deserialize<'de>,
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T: for<'de> Deserialize<'de>,