JSON-RPC: return mimetype and encoding for HTTP blobs

src/net/http.rs

@@ -3,20 +3,52 @@
 use std::time::Duration;
 
 use anyhow::{anyhow, Result};
+use mime::Mime;
 
 use crate::context::Context;
 use crate::socks::Socks5Config;
 
 const HTTP_TIMEOUT: Duration = Duration::from_secs(30);
 
+/// HTTP(S) GET response.
+#[derive(Debug)]
+pub struct Response {
+    /// Response body.
+    pub blob: Vec<u8>,
+
+    /// MIME type exntracted from the `Content-Type` header, if any.
+    pub mimetype: Option<String>,
+
+    /// Encoding extracted from the `Content-Type` header, if any.
+    pub encoding: Option<String>,
+}
+
 /// Retrieves the text contents of URL using HTTP GET request.
 pub async fn read_url(context: &Context, url: &str) -> Result<String> {
     Ok(read_url_inner(context, url).await?.text().await?)
 }
 
 /// Retrieves the binary contents of URL using HTTP GET request.
-pub async fn read_url_blob(context: &Context, url: &str) -> Result<Vec<u8>> {
-    Ok(read_url_inner(context, url).await?.bytes().await?.into())
+pub async fn read_url_blob(context: &Context, url: &str) -> Result<Response> {
+    let response = read_url_inner(context, url).await?;
+    let content_type = response
+        .headers()
+        .get(reqwest::header::CONTENT_TYPE)
+        .and_then(|value| value.to_str().ok())
+        .and_then(|value| value.parse::<Mime>().ok());
+    let mimetype = content_type
+        .as_ref()
+        .map(|mime| mime.essence_str().to_string());
+    let encoding = content_type.as_ref().and_then(|mime| {
+        mime.get_param(mime::CHARSET)
+            .map(|charset| charset.as_str().to_string())
+    });
+    let blob: Vec<u8> = response.bytes().await?.into();
+    Ok(Response {
+        blob,
+        mimetype,
+        encoding,
+    })
 }
 
 async fn read_url_inner(context: &Context, url: &str) -> Result<reqwest::Response> {