Trie

Package httprouter is a trie based high performance HTTP request router. A trivial example is: The router matches incoming requests by the request method and the path. If a handle is registered for this path and method, the router delegates the request to that function. For the methods GET, POST, PUT, PATCH and DELETE shortcut functions exist to register handles, for all other methods router.Handle can be used. The registered path, against which the router matches incoming requests, can contain two types of parameters: Named parameters are dynamic path segments. They match anything until the next '/' or the path end: Catch-all parameters match anything until the path end, including the directory index (the '/' before the catch-all). Since they match anything until the end, catch-all paramerters must always be the final path element. The value of parameters is saved as a slice of the Param struct, consisting each of a key and a value. The slice is passed to the Handle func as a third parameter. There are two ways to retrieve the value of a parameter:

Package httprouter is a trie based high performance HTTP request router. A trivial example is: The router matches incoming requests by the request method and the path. If a handle is registered for this path and method, the router delegates the request to that function. For the methods GET, POST, PUT, PATCH and DELETE shortcut functions exist to register handles, for all other methods router.Handle can be used. The registered path, against which the router matches incoming requests, can contain two types of parameters: Named parameters are dynamic path segments. They match anything until the next '/' or the path end: Catch-all parameters match anything until the path end, including the directory index (the '/' before the catch-all). Since they match anything until the end, catch-all parameters must always be the final path element. The value of parameters is saved as a slice of the Param struct, consisting each of a key and a value. The slice is passed to the Handle func as a third parameter. There are two ways to retrieve the value of a parameter:

Package httprouter is a trie based high performance HTTP request router. A trivial example is: The router matches incoming requests by the request method and the path. If a handle is registered for this path and method, the router delegates the request to that function. For the methods GET, POST, PUT, PATCH and DELETE shortcut functions exist to register handles, for all other methods router.Handle can be used. The registered path, against which the router matches incoming requests, can contain two types of parameters: Named parameters are dynamic path segments. They match anything until the next '/' or the path end: Catch-all parameters match anything until the path end, including the directory index (the '/' before the catch-all). Since they match anything until the end, catch-all parameters must always be the final path element. The value of parameters is saved as a slice of the Param struct, consisting each of a key and a value. The slice is passed to the Handle func as a third parameter. There are two ways to retrieve the value of a parameter:

Package httprouter is a trie based high performance HTTP request router. A trivial example is: The router matches incoming requests by the request method and the path. If a handle is registered for this path and method, the router delegates the request to that function. For the methods GET, POST, PUT, PATCH and DELETE shortcut functions exist to register handles, for all other methods router.Handle can be used. The registered path, against which the router matches incoming requests, can contain two types of parameters: Named parameters are dynamic path segments. They match anything until the next '/' or the path end: Catch-all parameters match anything until the path end, including the directory index (the '/' before the catch-all). Since they match anything until the end, catch-all parameters must always be the final path element. The value of parameters is saved as a slice of the Param struct, consisting each of a key and a value. The slice is passed to the Handle func as a third parameter. There are two ways to retrieve the value of a parameter:

package route provides http package-compatible routing library. It can route http requests by hostname, method, path and headers. Route defines simple language for matching requests based on Go syntax. Route provides series of matchers that follow the syntax: Host matcher: Path matcher: Method matcher: Header matcher: Matchers can be combined using && operator: Route library will join the trie-based matchers into one trie matcher when possible, for example: Will be combined into one trie for performance. If you add a third route: It wont be joined ito the trie, and would be matched separatedly instead.

Package hamt provides a reference implementation of the IPLD HAMT used in the Filecoin blockchain. It includes some optional flexibility such that it may be used for other purposes outside of Filecoin. HAMT is a "hash array mapped trie" https://en.wikipedia.org/wiki/Hash_array_mapped_trie. This implementation extends the standard form by including buckets for the key/value pairs at storage leaves and CHAMP mutation semantics https://michael.steindorfer.name/publications/oopsla15.pdf. The CHAMP invariant and mutation rules provide us with the ability to maintain canonical forms given any set of keys and their values, regardless of insertion order and intermediate data insertion and deletion. Therefore, for any given set of keys and their values, a HAMT using the same parameters and CHAMP semantics, the root node should always produce the same content identifier (CID). The HAMT algorithm hashes incoming keys and uses incrementing subsections of that hash digest at each level of its tree structure to determine the placement of either the entry or a link to a child node of the tree. A `bitWidth` determines the number of bits of the hash to use for index calculation at each level of the tree such that the root node takes the first `bitWidth` bits of the hash to calculate an index and as we move lower in the tree, we move along the hash by `depth x bitWidth` bits. In this way, a sufficiently randomizing hash function will generate a hash that provides a new index at each level of the data structure. An index comprising `bitWidth` bits will generate index values of `[ 0, 2^bitWidth )`. So a `bitWidth` of 8 will generate indexes of 0 to 255 inclusive. Each node in the tree can therefore hold up to `2^bitWidth` elements of data, which we store in an array. In the this HAMT and the IPLD HashMap we store entries in buckets. A `Set(key, value)` mutation where the index generated at the root node for the hash of key denotes an array index that does not yet contain an entry, we create a new bucket and insert the key / value pair entry. In this way, a single node can theoretically hold up to `2^bitWidth x bucketSize` entries, where `bucketSize` is the maximum number of elements a bucket is allowed to contain ("collisions"). In practice, indexes do not distribute with perfect randomness so this maximum is theoretical. Entries stored in the node's buckets are stored in key-sorted order. This HAMT implementation: • Fixes the `bucketSize` to 3. • Defaults the `bitWidth` to 8, however within Filecoin it uses 5 • Defaults the hash algorithm to the 64-bit variant of Murmur3-x64 The algorithm used here is identical to that of the IPLD HashMap algorithm specified at https://github.com/ipld/specs/blob/master/data-structures/hashmap.md. The specific parameters used by Filecoin and the DAG-CBOR block layout differ from the specification and are defined at https://github.com/ipld/specs/blob/master/data-structures/hashmap.md#Appendix-Filecoin-hamt-variant.

A quick and easy way to setup a RESTful JSON API Go-Json-Rest is a thin layer on top of net/http that helps building RESTful JSON APIs easily. It provides fast URL routing using a Trie based implementation, and helpers to deal with JSON requests and responses. It is not a high-level REST framework that transparently maps HTTP requests to procedure calls, on the opposite, you constantly have access to the underlying net/http objects. Example: Note about the URL routing: Instead of using the usual "evaluate all the routes and return the first regexp that matches" strategy, it uses a Trie data structure to perform the routing. This is more efficient, and scales better for a large number of routes. It supports the :param and *splat placeholders in the route strings.

Package runetrie provides an efficient, generic implementation of the trie (prefix tree) data structure for string matching operations. A trie, also known as a prefix tree, is a data structure that allows for efficient string lookups, prefix matching, and related operations with better performance characteristics than linear string comparisons in many scenarios. The implementation uses generic types allowing it to work with any string-like type. The package is designed for performance, with efficient lookups compared to linear string comparison approaches, especially when handling a large set of strings.

Package mux implements a high performance and powerful trie based url path router for Go.

Package trie implements a byte trie with edge compression.

Package trie is a pointer based Trie implementation. Since 0.1.0

Package triegen implements a code generator for a trie for associating unsigned integer values with UTF-8 encoded runes. Many of the go.text packages use tries for storing per-rune information. A trie is especially useful if many of the runes have the same value. If this is the case, many blocks can be expected to be shared allowing for information on many runes to be stored in little space. As most of the lookups are done directly on []byte slices, the tries use the UTF-8 bytes directly for the lookup. This saves a conversion from UTF-8 to runes and contributes a little bit to better performance. It also naturally provides a fast path for ASCII. Space is also an issue. There are many code points defined in Unicode and as a result tables can get quite large. So every byte counts. The triegen package automatically chooses the smallest integer values to represent the tables. Compacters allow further compression of the trie by allowing for alternative representations of individual trie blocks. triegen allows generating multiple tries as a single structure. This is useful when, for example, one wants to generate tries for several languages that have a lot of values in common. Some existing libraries for internationalization store all per-language data as a dynamically loadable chunk. The go.text packages are designed with the assumption that the user typically wants to compile in support for all supported languages, in line with the approach common to Go to create a single standalone binary. The multi-root trie approach can give significant storage savings in this scenario. triegen generates both tables and code. The code is optimized to use the automatically chosen data types. The following code is generated for a Trie or multiple Tries named "foo": type fooTrie The trie type. func newFooTrie(x int) *fooTrie Trie constructor, where x is the index of the trie passed to Gen. func (t *fooTrie) lookup(s []byte) (v uintX, sz int) The lookup method, where uintX is automatically chosen. func lookupString, lookupUnsafe and lookupStringUnsafe Variants of the above. var fooValues and fooIndex and any tables generated by Compacters. The core trie data. var fooTrieHandles Indexes of starter blocks in case of multiple trie roots. It is recommended that users test the generated trie by checking the returned value for every rune. Such exhaustive tests are possible as the the number of runes in Unicode is limited. Example_build shows how to build a simple trie. It assigns the value 1 to 100 random runes generated by randomRunes. Example_lookup demonstrates how to use the trie generated by Example_build.

Package trie implements trie tree (or prefix tree) data structure useful for things like prefix search/autocompletion. For now, it supports Insert, HasWord, HasPrefix and WordsByPrefix methods.