52 lines
2.3 KiB
Markdown
52 lines
2.3 KiB
Markdown
|
treap
|
||
|
|
=====
|
||
|
|
|
||
|
|
[]
|
||
|
|
(https://travis-ci.org/btcsuite/btcd)
|
||
|
|
|
||
|
|
Package treap implements a treap data structure that is used to hold ordered
|
||
|
|
key/value pairs using a combination of binary search tree and heap semantics.
|
||
|
|
It is a self-organizing and randomized data structure that doesn't require
|
||
|
|
complex operations to to maintain balance. Search, insert, and delete
|
||
|
|
operations are all O(log n). Both mutable and immutable variants are provided.
|
||
|
|
|
||
|
|
The mutable variant is typically faster since it is able to simply update the
|
||
|
|
treap when modifications are made. However, a mutable treap is not safe for
|
||
|
|
concurrent access without careful use of locking by the caller and care must be
|
||
|
|
taken when iterating since it can change out from under the iterator.
|
||
|
|
|
||
|
|
The immutable variant works by creating a new version of the treap for all
|
||
|
|
mutations by replacing modified nodes with new nodes that have updated values
|
||
|
|
while sharing all unmodified nodes with the previous version. This is extremely
|
||
|
|
useful in concurrent applications since the caller only has to atomically
|
||
|
|
replace the treap pointer with the newly returned version after performing any
|
||
|
|
mutations. All readers can simply use their existing pointer as a snapshot
|
||
|
|
since the treap it points to is immutable. This effectively provides O(1)
|
||
|
|
snapshot capability with efficient memory usage characteristics since the old
|
||
|
|
nodes only remain allocated until there are no longer any references to them.
|
||
|
|
|
||
|
|
Package treap is licensed under the copyfree ISC license.
|
||
|
|
|
||
|
|
## Usage
|
||
|
|
|
||
|
|
This package is only used internally in the database code and as such is not
|
||
|
|
available for use outside of it.
|
||
|
|
|
||
|
|
## Documentation
|
||
|
|
|
||
|
|
[]
|
||
|
|
(http://godoc.org/github.com/btcsuite/btcd/database/internal/treap)
|
||
|
|
|
||
|
|
Full `go doc` style documentation for the project can be viewed online without
|
||
|
|
installing this package by using the GoDoc site here:
|
||
|
|
http://godoc.org/github.com/btcsuite/btcd/database/internal/treap
|
||
|
|
|
||
|
|
You can also view the documentation locally once the package is installed with
|
||
|
|
the `godoc` tool by running `godoc -http=":6060"` and pointing your browser to
|
||
|
|
http://localhost:6060/pkg/github.com/btcsuite/btcd/database/internal/treap
|
||
|
|
|
||
|
|
## License
|
||
|
|
|
||
|
|
Package treap is licensed under the [copyfree](http://copyfree.org) ISC
|
||
|
|
License.
|