Refactor downloading of HTML pages

This change allows for parallel downloads of HTML pages upto a maximum
number of concurrent HTTP requests which is more efficient than
before where all HTTP requests are likely to begin at the same time.
This commit is contained in:
Kenneth Gitere 2021-02-06 17:03:02 +03:00
parent 6b62051942
commit 003953332f
5 changed files with 79 additions and 55 deletions

102
Cargo.lock generated
View file

@ -187,7 +187,7 @@ dependencies = [
"memchr",
"num_cpus",
"once_cell",
"pin-project-lite",
"pin-project-lite 0.1.11",
"pin-utils",
"slab",
"wasm-bindgen-futures",
@ -684,25 +684,52 @@ dependencies = [
]
[[package]]
name = "futures-channel"
version = "0.3.8"
name = "futures"
version = "0.3.12"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "4b7109687aa4e177ef6fe84553af6280ef2778bdb7783ba44c9dc3399110fe64"
checksum = "da9052a1a50244d8d5aa9bf55cbc2fb6f357c86cc52e46c62ed390a7180cf150"
dependencies = [
"futures-channel",
"futures-core",
"futures-executor",
"futures-io",
"futures-sink",
"futures-task",
"futures-util",
]
[[package]]
name = "futures-channel"
version = "0.3.12"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "f2d31b7ec7efab6eefc7c57233bb10b847986139d88cc2f5a02a1ae6871a1846"
dependencies = [
"futures-core",
"futures-sink",
]
[[package]]
name = "futures-core"
version = "0.3.8"
version = "0.3.12"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "847ce131b72ffb13b6109a221da9ad97a64cbe48feb1028356b836b47b8f1748"
checksum = "79e5145dde8da7d1b3892dad07a9c98fc04bc39892b1ecc9692cf53e2b780a65"
[[package]]
name = "futures-executor"
version = "0.3.12"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "e9e59fdc009a4b3096bf94f740a0f2424c082521f20a9b08c5c07c48d90fd9b9"
dependencies = [
"futures-core",
"futures-task",
"futures-util",
]
[[package]]
name = "futures-io"
version = "0.3.8"
version = "0.3.12"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "611834ce18aaa1bd13c4b374f5d653e1027cf99b6b502584ff8c9a64413b30bb"
checksum = "28be053525281ad8259d47e4de5de657b25e7bac113458555bb4b70bc6870500"
[[package]]
name = "futures-lite"
@ -715,15 +742,15 @@ dependencies = [
"futures-io",
"memchr",
"parking",
"pin-project-lite",
"pin-project-lite 0.1.11",
"waker-fn",
]
[[package]]
name = "futures-macro"
version = "0.3.8"
version = "0.3.12"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "77408a692f1f97bcc61dc001d752e00643408fbc922e4d634c655df50d595556"
checksum = "c287d25add322d9f9abdcdc5927ca398917996600182178774032e9f8258fedd"
dependencies = [
"proc-macro-hack",
"proc-macro2",
@ -733,31 +760,33 @@ dependencies = [
[[package]]
name = "futures-sink"
version = "0.3.8"
version = "0.3.12"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "f878195a49cee50e006b02b93cf7e0a95a38ac7b776b4c4d9cc1207cd20fcb3d"
checksum = "caf5c69029bda2e743fddd0582d1083951d65cc9539aebf8812f36c3491342d6"
[[package]]
name = "futures-task"
version = "0.3.8"
version = "0.3.12"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "7c554eb5bf48b2426c4771ab68c6b14468b6e76cc90996f528c3338d761a4d0d"
checksum = "13de07eb8ea81ae445aca7b69f5f7bf15d7bf4912d8ca37d6645c77ae8a58d86"
dependencies = [
"once_cell",
]
[[package]]
name = "futures-util"
version = "0.3.8"
version = "0.3.12"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "d304cff4a7b99cfb7986f7d43fbe93d175e72e704a8860787cc95e9ffd85cbd2"
checksum = "632a8cd0f2a4b3fdea1657f08bde063848c3bd00f9bbf6e256b8be78802e624b"
dependencies = [
"futures-channel",
"futures-core",
"futures-io",
"futures-macro",
"futures-sink",
"futures-task",
"memchr",
"pin-project 1.0.2",
"pin-project-lite 0.2.4",
"pin-utils",
"proc-macro-hack",
"proc-macro-nested",
@ -911,7 +940,7 @@ dependencies = [
"cookie",
"futures-lite",
"infer",
"pin-project-lite",
"pin-project-lite 0.1.11",
"rand 0.7.3",
"serde",
"serde_json",
@ -1247,6 +1276,7 @@ dependencies = [
"async-std",
"clap",
"epub-builder",
"futures",
"html5ever",
"kuchiki",
"lazy_static",
@ -1328,16 +1358,7 @@ version = "0.4.27"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "2ffbc8e94b38ea3d2d8ba92aea2983b503cd75d0888d75b86bb37970b5698e15"
dependencies = [
"pin-project-internal 0.4.27",
]
[[package]]
name = "pin-project"
version = "1.0.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "9ccc2237c2c489783abd8c4c80e5450fc0e98644555b1364da68cc29aa151ca7"
dependencies = [
"pin-project-internal 1.0.2",
"pin-project-internal",
]
[[package]]
@ -1351,23 +1372,18 @@ dependencies = [
"syn",
]
[[package]]
name = "pin-project-internal"
version = "1.0.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "f8e8d2bf0b23038a4424865103a4df472855692821aab4e4f5c3312d461d9e5f"
dependencies = [
"proc-macro2",
"quote",
"syn",
]
[[package]]
name = "pin-project-lite"
version = "0.1.11"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "c917123afa01924fc84bb20c4c03f004d9c38e5127e3c039bbf7f4b9c76a2f6b"
[[package]]
name = "pin-project-lite"
version = "0.2.4"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "439697af366c49a6d0a010c56a0d97685bc140ce0d377b13a2ea2aa42d64a827"
[[package]]
name = "pin-utils"
version = "0.1.0"
@ -1889,7 +1905,7 @@ dependencies = [
"log 0.4.11",
"mime_guess",
"once_cell",
"pin-project-lite",
"pin-project-lite 0.1.11",
"serde",
"serde_json",
"web-sys",
@ -2043,7 +2059,7 @@ checksum = "b0987850db3733619253fe60e17cb59b82d37c7e6c0236bb81e4d6b87c879f27"
dependencies = [
"cfg-if 0.1.10",
"log 0.4.11",
"pin-project-lite",
"pin-project-lite 0.1.11",
"tracing-attributes",
"tracing-core",
]
@ -2074,7 +2090,7 @@ version = "0.2.4"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "ab7bb6f14721aa00656086e9335d363c5c8747bae02ebe32ea2c7dece5689b4c"
dependencies = [
"pin-project 0.4.27",
"pin-project",
"tracing",
]

View file

@ -15,6 +15,7 @@ readme = "README.md"
async-std = "1.7.0"
clap = "2.33.3"
epub-builder = "0.4.8"
futures = "0.3.12"
html5ever = "0.25.1"
kuchiki = "0.8.1"
lazy_static = "1.4.0"

View file

@ -62,11 +62,15 @@ It takes a url and downloads the article content from it and saves it to an epub
pub struct AppConfig {
urls: Vec<String>,
max_conn: usize,
}
impl AppConfig {
fn new() -> Self {
Self { urls: vec![] }
Self {
urls: vec![],
max_conn: 8,
}
}
fn set_urls(&mut self, urls: Vec<String>) {
@ -76,4 +80,7 @@ impl AppConfig {
pub fn urls(&self) -> &Vec<String> {
&self.urls
}
pub fn max_conn(&self) -> usize {
self.max_conn
}
}

View file

@ -57,7 +57,6 @@ pub async fn download_images(
extractor: &mut Extractor,
article_origin: &Url,
) -> async_std::io::Result<()> {
extractor.extract_img_urls();
let mut async_download_tasks = Vec::with_capacity(extractor.img_urls.len());
if extractor.img_urls.len() > 0 {
println!("Downloading images...");

View file

@ -1,7 +1,9 @@
#[macro_use]
extern crate lazy_static;
use async_std::stream;
use async_std::task;
use futures::stream::StreamExt;
use url::Url;
mod cli;
@ -12,33 +14,32 @@ mod extractor;
mod http;
mod moz_readability;
use cli::AppConfig;
use epub::generate_epub;
use extractor::Extractor;
use http::{download_images, fetch_url};
use extractor::Extractor;
fn main() {
let app_config = cli::cli_init();
if !app_config.urls().is_empty() {
download(app_config.urls().clone());
download(app_config);
}
}
fn download(urls: Vec<String>) {
let mut async_url_tasks = Vec::with_capacity(urls.len());
for url in urls {
async_url_tasks.push(task::spawn(async move { fetch_url(&url).await }));
}
fn download(app_config: AppConfig) {
task::block_on(async {
for url_task in async_url_tasks {
match url_task.await {
let urls_iter = app_config.urls().iter().map(|url| fetch_url(url));
let mut responses = stream::from_iter(urls_iter).buffered(app_config.max_conn());
while let Some(fetch_result) = responses.next().await {
match fetch_result {
Ok((url, html)) => {
println!("Extracting");
let mut extractor = Extractor::from_html(&html);
extractor.extract_content(&url);
if extractor.article().is_some() {
extractor.extract_img_urls();
download_images(&mut extractor, &Url::parse(&url).unwrap())
.await
.expect("Unable to download images");