by Tim Henderson (tim.tadh@gmail.com)
Copyright 2013, Licensed under the GPL version 2. Please reach out to me directly if you require another licensing option. I am willing to work with you.
To collect many important data structures for usage in go programs. Golang's standard library lacks many useful and important structures. This library attempts to fill the gap. I have implemented data-structure's as I have needed them. If there is a missing structure or even just a missing (or incorrect) method open an issue, send a pull request, or send an email patch.
The library also provides generic types to allow the user to swap out various data structures transparently. The interfaces provide operation for adding, removing, retrieving objects from collections as well as iterating over the collection using functional iterators.
Finally, the tree sub-package provides a variety of generic tree traversals. The tree traversals and other iterators in the package use a functional iteration technique detailed on my blog.
I hope you find my library useful. If you are using it drop me a line I would love to hear about it.
Similar to a Java ArrayList or a Python or Ruby "list". There is a version
(called Sortable) which integrates with the "sort"
package from the standard
library.
Keeps the ArrayList in sorted order for you.
Built on top of *list.Sorted
, it provides basic set operations. With
set.SortedSet
you don't have to write code re-implementing sets with the
map[type]
datatype. Supports: intersection, union, set difference and overlap
tests.
An AVL tree is a height balanced binary search tree. It is commonly taught in algorithms courses.
This version of the classic is immutable and should be thread safe due to immutability. However, there is a performance hit:
BenchmarkAvlTree 10000 166657 ns/op
BenchmarkImmutableAvlTree 5000 333709 ns/op
A ternary search trie is a symbol table specialized to byte strings. It can be used to build a suffix tree for full text string indexing. However, even without a suffix tree it is still a great structure for flexible prefix searches.
A B+Tree is a general symbol table usually used for database indices. This implementation is not currently thread safe. It uses the structure detailed in the link and was ported from my file-structures repository.
See hashtable/hashtable.go
. An implementation of the classic hash table with
separate chaining to handle collisions.
See hashtables/linhash.go
. An implementation of Linear
Hashing, a technique usually used
for secondary storage hash tables. Often employed by databases and file systems
for hash indices. This version is mostly instructional see the
accompanying blog post.
If you want the "real" disk backed version you want to check my
file-structures repository. See
the linhash
directory.
Note: these benchmarsk are fairly old and probably not easy to understand. Look at the relative difference not the absolute numbers as they are misleading. Each benchmark does many operations per "test" which makes it difficult to compare these numbers to numbers found elsewhere.
Benchmarks Put + Remove
$ go test -v -bench '.*' \
> github.com/timtadh/data-structures/hashtable
> github.com/timtadh/data-structures/tree/...
> github.com/timtadh/data-structures/trie
BenchmarkGoMap 50000 30051 ns/op
BenchmarkMLHash 20000 78840 ns/op
BenchmarkHash 20000 81012 ns/op
BenchmarkTST 10000 149985 ns/op
BenchmarkBpTree 10000 185134 ns/op
BenchmarkAvlTree 10000 193069 ns/op
BenchmarkImmutableAvlTree 5000 367602 ns/op
BenchmarkLHash 1000 2743693 ns/op
Benchmarks Put
BenchmarkGoMap 100000 22036 ns/op
BenchmarkMLHash 50000 52104 ns/op
BenchmarkHash 50000 53426 ns/op
BenchmarkTST 50000 69852 ns/op
BenchmarkBpTree 20000 76124 ns/op
BenchmarkAvlTree 10000 142104 ns/op
BenchmarkImmutableAvlTree 10000 302196 ns/op
BenchmarkLHash 1000 1739710 ns/op
The performance of the in memory linear hash (MLHash) is slightly improved since
the blog post do
to the usage of an AVL Tree tree/avltree.go
instead of an unbalanced binary
search tree.
-
fs2 Memory mapped datastructures. A B+Tree, a list, and a platform for implementing more.
-
file-structures The previous version of fs2 of disk based file-structures. Also includes a linear virtual hashing implementation.