Spider

crate version

Multithreaded web crawler/indexer using isolates and IPC channels for communication.

Dependencies

On Linux

Example

This is a basic blocking example crawling a web page, add spider to your Cargo.toml:

toml [dependencies] spider = "1.19.4"

And then the code:

```rust,no_run extern crate spider;

use spider::website::Website; use spider::tokio;

[tokio::main]

async fn main() { let url = "https://choosealicense.com"; let mut website: Website = Website::new(&url); website.crawl().await;

for page in website.get_pages() {
    println!("- {}", page.get_url());
}

} ```

You can use Configuration object to configure your crawler:

```rust // .. let mut website: Website = Website::new("https://choosealicense.com"); website.configuration.blacklisturl.push("https://choosealicense.com/licenses/".tostring()); website.configuration.respectrobotstxt = true; website.configuration.subdomains = true; website.configuration.tld = false; website.configuration.delay = 0; // Defaults to 0 ms due to concurrency handling website.configuration.channelbuffer = 100; // Defaults to 50 - tune this depending on onlinkfindcallback website.configuration.useragent = "myapp/version".tostring(); // Defaults to spider/x.y.z, where x.y.z is the library version website.onlinkfind_callback = |s| { println!("link target: {}", s); s }; // Callback to run on each link find

website.crawl().await; ```

Regex Blacklisting

There is an optional "regex" crate that can be enabled:

toml [dependencies] spider = { version = "1.19.4", features = ["regex"] }

```rust,no_run extern crate spider;

use spider::website::Website; use spider::tokio;

[tokio::main]

async fn main() { let mut website: Website = Website::new("https://choosealicense.com"); website.configuration.blacklisturl.push("/licenses/".tostring()); website.crawl().await;

for page in website.get_pages() {
    println!("- {}", page.get_url());
}

} ```

Features

Currently we have three optional feature flags. Regex blacklisting, jemaloc backend, and randomizing User-Agents.

toml [dependencies] spider = { version = "1.19.4", features = ["regex", "ua_generator"] }

Jemalloc performs better for concurrency and allows memory to release easier.

This changes the global allocator of the program so test accordingly to measure impact.

toml [dependencies] spider = { version = "1.19.4", features = ["jemalloc"] }

Blocking

If you need a blocking sync imp use a version prior to v1.12.0.

Pause, Resume, and Shutdown

If you are performing large workloads you may need to control the crawler using the following:

```rust

[tokio::main]

async fn main() { use spider::utils::{pause, resume}; let url = "https://choosealicense.com/"; let mut website: Website = Website::new(&url);

tokio::spawn(async move {
    pause(url).await;
    sleep(Duration::from_millis(5000)).await;
    resume(url).await;
});

website.crawl().await;

} ```

Shutdown crawls

```rust

[tokio::main]

async fn main() { use spider::utils::{shutdown}; let url = "https://choosealicense.com/"; let mut website: Website = Website::new(&url);

tokio::spawn(async move {
    // really long crawl force shutdown ( 30 is a long time for most websites )
    sleep(Duration::from_secs(30)).await;
    shutdown(url).await;
});

website.crawl().await;

} ```