Crate dyer

dyer is designed for reliable, flexible and fast web-crawling, providing some high-level, comprehensive features without compromising speed.

By means of event-driven, non-blocking I/O tokio and powerful, reliable Rust programming language, inspired by scrapy, dyer provides some high-level features:

• asynchronous, concurrent streamimg and I/O, make the best of thread pool, network, and system resource.
• event-driven, once you set the initials and recursive generator of Task, dyer will handle the rest of it.
• user-friendly, considering the philosophy of rust programming language, more source code, proper architecture may set up yourself in a dilemma when efficiency and learning cost are taken into consideration. dyer offers high-level,flexible wrappers and APIs what does a lot for you.

Get Started by installing dyer-cli and looking over the examples.

Main Functionalities

Dyer is newly developed rust library, and has achieved some basic functionalities for building a crawer, web service and data processing. Nevertheless, it can tackle most common problems you meet.

Real-browser Customization

It is disabled by default, but As you wish you can enable it by specifying ArgProfile. In general, for each feeded Task, dyer will fake a Profile and combines them into a Request to meet the requirement of the target site. By means of ffi interface of and web assemble of rust, combination with javascript or python script may do you a favor hopefully.

Signal Handling

Think about a scenario that errors, bugs and unexpected accidents are found when your app is running, what would you do? Stop the app, the entire program and the data are corupted. Nope, the result is not reliable. dyer will backup your history between certain gap, resumption is at your choice.

Run-time Control

Each Task and each Profile is scheduled with some gap, has a time stamp for validation, only the expired can be feeded to engine of dyer. Nevertheless dyer will limit the Request sent to poll, the Profile to make, Task to load or store and so on see ArgApp.

Quick Start

dyer-cli is a handy tool for your easy and fast use of dyer, and recommanded to intergrate with other dependencies. with rustup and cargo installed, the following code helps you get the tool:

cargo install dyer-cli

Once installed, run dyer-cli in your terminal or cmd prompt, it prints some info like

Handy tool for dyer

then dyer-cli is successfully installed.

Create A Project

Dyer-cli generates a template that contains many useful instances and instructions when using dyer with following code:

dyer-cli new myproject

It will create a project called myproject and the files layout displays:

|___Cargo.toml
|___Readme.md
|___data/
|___data/tasks/
|___src/
    |___src/entity.rs
    |___src/parser.rs
    |___src/spider.rs
    |___src/middleware.rs
    |___src/pipeline.rs
    |___src/lib.rs

Main functionality of each file:

• the entity.rs contains entities/data structure to be used/collected
• the parser.rs contains functions that extract entities from response
• the spider.rs contains initial when opening and final things to do when closing
• the middleware.rs contains Some middlewares that process data at runtime
• the pipeline.rs contains entities manipulation including data-storage, displsying and so on
• the lib.rs exports all modules inside the directory, just do nothing here normally
• Cargo.toml is the basic configuration of the project
• README.md contains some instructions of the project
• data/ place to store/load files of App when load-balancing and backup

Then it is your show time, basically there are simple example items(function, enum, struct) in each file you can follow. After that check your code

dyer-cli check

if you run it the first time, dyer-cli will download the crates and then check the code. if some warning happens such as unused import or dead code the command does a lot for you:

dyer-cli fix

however it won’t help if some errors occur, if so, you have to debug the code manually.

Edit config file in the root directory

the file contains some configurations of ArgApp that will update periodically, for more details see config Configuration

When the program compiles, haha run it:

dyer-cli run

Short as it seems, here represents the normal procedure to write your program. It is believed that learning by example is the best, and some examples are provided to illustrate how to use.

Features to be added

✅ Profile customization

✅ Periodic Configuration Update

✅ Dyer-cli Command-Line Tool Support

✅ Interrupt and Resume Support

⬜️ Proxy Support

⬜️ Debugging Support(not bad though for now)

⬜️ Autothrottling and more customized plugins support

⬜️ More to go

Problem And Feedback

It is, of course, probable that bugs and errors lie in somewhere, and defects may appear in an unexpected way, if you got any one, comments and suggestions are welcome, please new a issue in my github.

Modules

component	Instructions of components including client, profile, request, response, task, utils.
engine	An instruction of App and its configuration ArgApp
plugin	Instructions of plugins including middleware, pipeline and their usage.

Macros

plug	Macro that make a plugin at ease including PipeLine MiddleWare