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wip: async

This commit is contained in:
Jan Lukas Gernert 2019-11-10 14:43:59 +01:00
parent 5f82872d1f
commit 4b8af0d709
3 changed files with 74 additions and 60 deletions

View file

@ -60,10 +60,10 @@ impl ArticleScraper {
})
}
pub fn parse(&self, url: url::Url, download_images: bool) -> Result<Article, ScraperError> {
pub async fn parse(&self, url: url::Url, download_images: bool) -> Result<Article, ScraperError> {
info!("Scraping article: {}", url.as_str());
let response = self.client.head(url.clone()).send()
let response = self.client.head(url.clone()).send().await
.map_err(|err| {
error!("Failed head request to: {} - {}", url.as_str(), err.description());
err
@ -105,7 +105,7 @@ impl ArticleScraper {
ArticleScraper::generate_head(&mut root, &document)?;
self.parse_first_page(&mut article, &url, &mut root, config)?;
self.parse_pages(&mut article, &url, &mut root, config).await?;
let context = Context::new(&document).map_err(|()| {
error!("Failed to create xpath context for extracted article");
@ -123,7 +123,7 @@ impl ArticleScraper {
}
if download_images {
if let Err(error) = self.image_downloader.download_images_from_context(&context) {
if let Err(error) = self.image_downloader.download_images_from_context(&context).await {
error!("Downloading images failed: {}", error);
}
}
@ -145,9 +145,9 @@ impl ArticleScraper {
Ok(article)
}
fn parse_first_page(&self, article: &mut Article, url: &url::Url, root: &mut Node, config: &GrabberConfig) -> Result<(), ScraperError> {
async fn parse_pages(&self, article: &mut Article, url: &url::Url, root: &mut Node, config: &GrabberConfig) -> Result<(), ScraperError> {
let mut html = ArticleScraper::download(&url, &self.client)?;
let mut html = ArticleScraper::download(&url, &self.client).await?;
parse_html!(html, config, xpath_ctx);
// check for single page link
@ -158,7 +158,7 @@ impl ArticleScraper {
// parse again with single page url
debug!("Single page link found {}", result);
let single_page_url = url::Url::parse(&result).context(ScraperErrorKind::Url)?;
return self.parse_single_page(article, &single_page_url, root, config);
return self.parse_single_page(article, &single_page_url, root, config).await;
}
}
@ -166,22 +166,27 @@ impl ArticleScraper {
ArticleScraper::strip_junk(&xpath_ctx, config, &url);
ArticleScraper::extract_body(&xpath_ctx, root, config)?;
self.check_for_next_page(&xpath_ctx, config, root)
loop {
println!("loop");
if let Some(url) = self.check_for_next_page(&xpath_ctx, config) {
println!("url {}", url);
let mut html = ArticleScraper::download(&url, &self.client).await?;
parse_html!(html, config, new_xpath_ctx);
ArticleScraper::strip_junk(&new_xpath_ctx, config, &url);
ArticleScraper::extract_body(&new_xpath_ctx, root, config)?;
xpath_ctx = new_xpath_ctx;
} else {
println!("break");
break;
}
}
Ok(())
}
fn parse_next_page(&self, url: &url::Url, root: &mut Node, config: &GrabberConfig) -> Result<(), ScraperError> {
let mut html = ArticleScraper::download(&url, &self.client)?;
parse_html!(html, config, xpath_ctx);
ArticleScraper::strip_junk(&xpath_ctx, config, &url);
ArticleScraper::extract_body(&xpath_ctx, root, config)?;
self.check_for_next_page(&xpath_ctx, config, root)
}
fn parse_single_page(&self, article: &mut Article, url: &url::Url, root: &mut Node, config: &GrabberConfig) -> Result<(), ScraperError> {
async fn parse_single_page(&self, article: &mut Article, url: &url::Url, root: &mut Node, config: &GrabberConfig) -> Result<(), ScraperError> {
let mut html = ArticleScraper::download(&url, &self.client)?;
let mut html = ArticleScraper::download(&url, &self.client).await?;
parse_html!(html, config, xpath_ctx);
ArticleScraper::extract_metadata(&xpath_ctx, config, article);
ArticleScraper::strip_junk(&xpath_ctx, config, &url);
@ -190,9 +195,9 @@ impl ArticleScraper {
Ok(())
}
fn download(url: &url::Url, client: &reqwest::Client) -> Result<String, ScraperError> {
async fn download(url: &url::Url, client: &reqwest::Client) -> Result<String, ScraperError> {
let mut response = client.get(url.as_str()).send()
let response = client.get(url.as_str()).send().await
.map_err(|err| {
error!("Downloading HTML failed: GET {} - {}", url.as_str(), err.description());
err
@ -200,13 +205,14 @@ impl ArticleScraper {
.context(ScraperErrorKind::Http)?;
if response.status().is_success() {
let text = response.text().context(ScraperErrorKind::Http)?;
let headers = response.headers().clone();
let text = response.text().await.context(ScraperErrorKind::Http)?;
{
if let Some(decoded_html) = ArticleScraper::decode_html(&text, ArticleScraper::get_encoding_from_html(&text)) {
return Ok(decoded_html)
}
if let Some(decoded_html) = ArticleScraper::decode_html(&text, ArticleScraper::get_encoding_from_http_header(response.headers())) {
if let Some(decoded_html) = ArticleScraper::decode_html(&text, ArticleScraper::get_encoding_from_http_header(&headers)) {
return Ok(decoded_html)
}
}
@ -357,7 +363,7 @@ impl ArticleScraper {
let xpath = &format!("//*[contains(@class, '{}') or contains(@id, '{}')]", id_or_class, id_or_class);
evaluate_xpath!(context, xpath, node_vec);
for mut node in node_vec {
node.unlink();
//node.unlink();
}
Ok(())
}
@ -441,8 +447,9 @@ impl ArticleScraper {
}
fn get_attribute(context: &Context, xpath: &str, attribute: &str) -> Result<String, ScraperError> {
println!("get attribute {}", attribute);
evaluate_xpath!(context, xpath, node_vec);
println!("found {}", node_vec.len());
xpath_result_empty!(node_vec, xpath);
for node in node_vec {
if let Some(value) = node.get_attribute(attribute) {
@ -619,18 +626,19 @@ impl ArticleScraper {
Ok(found_something)
}
fn check_for_next_page(&self, context: &Context, config: &GrabberConfig, root: &mut Node) -> Result<(), ScraperError> {
fn check_for_next_page(&self, context: &Context, config: &GrabberConfig) -> Option<url::Url> {
if let Some(next_page_xpath) = config.next_page_link.clone() {
if let Ok(next_page_string) = ArticleScraper::get_attribute(&context, &next_page_xpath, "href") {
if let Ok(next_page_url) = url::Url::parse(&next_page_string) {
return self.parse_next_page(&next_page_url, root, config)
println!("next_page_url: {}", next_page_url);
return Some(next_page_url)
}
}
}
// last page reached
Ok(())
None
}
fn generate_head(root: &mut Node, document: &Document) -> Result<(), ScraperError> {
@ -692,28 +700,28 @@ impl ArticleScraper {
mod tests {
use crate::*;
#[test]
pub fn golem() {
#[tokio::test]
async fn golem() {
let config_path = PathBuf::from(r"./resources/tests/golem");
let out_path = PathBuf::from(r"./test_output");
let url = url::Url::parse("https://www.golem.de/news/http-error-418-fehlercode-ich-bin-eine-teekanne-darf-bleiben-1708-129460.html").unwrap();
let grabber = ArticleScraper::new(config_path).unwrap();
let article = grabber.parse(url, true).unwrap();
let article = grabber.parse(url, true).await.unwrap();
article.save_html(&out_path).unwrap();
assert_eq!(article.title, Some(String::from("HTTP Error 418: Fehlercode \"Ich bin eine Teekanne\" darf bleiben")));
assert_eq!(article.author, Some(String::from("Hauke Gierow")));
}
#[test]
pub fn phoronix() {
#[tokio::test]
async fn phoronix() {
let config_path = PathBuf::from(r"./resources/tests/phoronix");
let out_path = PathBuf::from(r"./test_output");
let url = url::Url::parse("http://www.phoronix.com/scan.php?page=article&item=amazon_ec2_bare&num=1").unwrap();
let grabber = ArticleScraper::new(config_path).unwrap();
let article = grabber.parse(url, true).unwrap();
let article = grabber.parse(url, true).await.unwrap();
article.save_html(&out_path).unwrap();
assert_eq!(article.title, Some(String::from("Amazon EC2 Cloud Benchmarks Against Bare Metal Systems")));