Package trie provides a data structure for autocompletion searching of strings.
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 separately instead.
Package radixtree implements an Adaptive Radix Tree, aka compressed trie or compact prefix tree. It is adaptive in the sense that nodes are not constant size, having as few or many children as needed to branch to all subtrees. This package implements a radix-256 tree where each key symbol (radix) is a byte, allowing up to 256 possible branches to traverse to the next node. The implementation is optimized for Get performance and allocates 0 bytes of heap memory per Get; therefore no garbage to collect. Once the radix tree is built, it can be repeatedly searched quickly. Concurrent searches are safe since these do not modify the radixtree. Access is not synchronized (not concurrent safe with writes), allowing the caller to synchronize, if needed, in whatever manner works best for the application. The API uses string keys, since strings are immutable and therefore it is not necessary make a copy of the key provided to the radix tree.
Ternary Search Tree
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 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 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 mux implements a high performance and powerful trie based url path router for Go.