github.com/lbryio/lbcd@v0.22.119/database/internal/treap/README.md (about) 1 treap 2 ===== 3 4 [](https://github.com/lbryio/lbcd/actions) 5 [](http://copyfree.org) 6 [](https://pkg.go.dev/github.com/lbryio/lbcd/database/internal/treap) 7 8 Package treap implements a treap data structure that is used to hold ordered 9 key/value pairs using a combination of binary search tree and heap semantics. 10 It is a self-organizing and randomized data structure that doesn't require 11 complex operations to maintain balance. Search, insert, and delete 12 operations are all O(log n). Both mutable and immutable variants are provided. 13 14 The mutable variant is typically faster since it is able to simply update the 15 treap when modifications are made. However, a mutable treap is not safe for 16 concurrent access without careful use of locking by the caller and care must be 17 taken when iterating since it can change out from under the iterator. 18 19 The immutable variant works by creating a new version of the treap for all 20 mutations by replacing modified nodes with new nodes that have updated values 21 while sharing all unmodified nodes with the previous version. This is extremely 22 useful in concurrent applications since the caller only has to atomically 23 replace the treap pointer with the newly returned version after performing any 24 mutations. All readers can simply use their existing pointer as a snapshot 25 since the treap it points to is immutable. This effectively provides O(1) 26 snapshot capability with efficient memory usage characteristics since the old 27 nodes only remain allocated until there are no longer any references to them. 28 29 Package treap is licensed under the copyfree ISC license. 30 31 ## Usage 32 33 This package is only used internally in the database code and as such is not 34 available for use outside of it. 35 36 ## License 37 38 Package treap is licensed under the [copyfree](http://copyfree.org) ISC 39 License.