ok

Cargo.lock

@@ -1451,6 +1451,7 @@ dependencies = [
  "calamine",
  "dialoguer",
  "image",
+ "rayon",
  "reqwest",
  "rfd",
  "rust_xlsxwriter",

Cargo.toml

@@ -7,6 +7,7 @@ edition = "2024"
 calamine = "0.31"
 dialoguer = "0.11"
 image = "0.25"
+rayon = "1.10"
 reqwest = { version = "0.12", default-features = false, features = ["blocking", "rustls-tls"] }
 rfd = "0.15"
 rust_xlsxwriter = "0.83"

README.md

@@ -9,6 +9,7 @@ Then it reads the header row and asks you to map three columns using the same TU
 
 After mapping, it downloads each image from the selected `Url` column, reads image metadata, and writes a new Excel file next to the source workbook as `result_[uuid].xlsx`.
 For testing, it currently processes only the first 100 non-empty URL rows.
+Image processing runs in parallel workers with timeouts and response-size guards to avoid long hangs.
 
 Output columns:
 - `Cikkszám`

src/main.rs

@@ -1,14 +1,30 @@
-use std::{
-    path::{Path, PathBuf},
-    time::Duration
-};
 use calamine::{Data, Range, Reader, open_workbook_auto};
 use dialoguer::{Select, theme::ColorfulTheme};
 use image::GenericImageView;
+use rayon::prelude::*;
+use rayon::{ThreadPool, ThreadPoolBuilder};
 use reqwest::blocking::Client;
+use reqwest::header::CONTENT_TYPE;
 use rust_xlsxwriter::Workbook;
+use std::{
+    io::Read,
+    path::{Path, PathBuf},
+    sync::{
+        Arc,
+        atomic::{AtomicUsize, Ordering},
+    },
+    thread,
+    time::Duration,
+};
 use uuid::Uuid;
 
+const MAX_TEST_ROWS: usize = 100_000_000;
+const MAX_CONCURRENCY: usize = 6;
+const REQUEST_TIMEOUT_SECS: u64 = 20;
+const CONNECT_TIMEOUT_SECS: u64 = 5;
+const MAX_IMAGE_BYTES: usize = 20 * 1024 * 1024;
+const MAX_RETRIES: usize = 1;
+
 fn main() {
     let Some(file) = rfd::FileDialog::new()
         .add_filter("Excel files", &["xls", "xlsx"])
@@ -79,11 +95,16 @@ fn main() {
         eprintln!("No data rows with URL values were found.");
         std::process::exit(1);
     }
-    println!("Processing first {} rows for testing.", input_rows.len());
+    println!(
+        "Processing up to {} rows for testing (found {}).",
+        MAX_TEST_ROWS,
+        input_rows.len()
+    );
 
     let client = match Client::builder()
         .user_agent("o8_pics_size/0.1")
-        .timeout(Duration::from_secs(45))
+        .connect_timeout(Duration::from_secs(CONNECT_TIMEOUT_SECS))
+        .timeout(Duration::from_secs(REQUEST_TIMEOUT_SECS))
         .build()
     {
         Ok(client) => client,
@@ -93,11 +114,14 @@ fn main() {
         }
     };
 
-    let mut output_rows = Vec::new();
+    let thread_pool = build_thread_pool(MAX_CONCURRENCY);
+    let progress = Arc::new(AtomicUsize::new(0));
     let total = input_rows.len();
-    for (index, row) in input_rows.iter().enumerate() {
-        println!("[{}/{}] Fetching {}", index + 1, total, row.url);
-        let metadata = match fetch_image_metadata(&client, &row.url) {
+    let output_rows = thread_pool.install(|| {
+        input_rows
+            .par_iter()
+            .map(|row| {
+                let metadata = match fetch_image_metadata_with_retry(&client, &row.url) {
                     Ok(metadata) => Some(metadata),
                     Err(err) => {
                         eprintln!("Failed to fetch '{}': {}", row.url, err);
@@ -105,13 +129,18 @@ fn main() {
                     }
                 };
 
-        output_rows.push(OutputRow {
+                let completed = progress.fetch_add(1, Ordering::Relaxed) + 1;
+                println!("[{}/{}] Processed {}", completed, total, row.url);
+
+                OutputRow {
                     cikkszam: row.cikkszam.clone(),
                     sequence: row.sequence.clone(),
                     url: row.url.clone(),
                     metadata,
-        });
                 }
+            })
+            .collect::<Vec<_>>()
+    });
 
     let output_path = build_output_path(&file);
     if let Err(err) = write_results_excel(&output_path, &output_rows) {
@@ -262,6 +291,10 @@ fn collect_input_rows(
             sequence: cell_string(row.get(sequence_idx)),
             url,
         });
+
+        if rows.len() >= MAX_TEST_ROWS {
+            break;
+        }
     }
 
     rows
@@ -274,6 +307,24 @@ fn cell_string(cell: Option<&Data>) -> String {
     }
 }
 
+fn fetch_image_metadata_with_retry(client: &Client, url: &str) -> Result<ImageMetadata, String> {
+    let mut last_error: Option<String> = None;
+
+    for attempt in 0..=MAX_RETRIES {
+        match fetch_image_metadata(client, url) {
+            Ok(metadata) => return Ok(metadata),
+            Err(err) => {
+                last_error = Some(err);
+                if attempt < MAX_RETRIES {
+                    thread::sleep(Duration::from_millis(350 * (attempt + 1) as u64));
+                }
+            }
+        }
+    }
+
+    Err(last_error.unwrap_or_else(|| "unknown error".to_string()))
+}
+
 fn fetch_image_metadata(client: &Client, url: &str) -> Result<ImageMetadata, String> {
     let response = client
         .get(url)
@@ -282,9 +333,35 @@ fn fetch_image_metadata(client: &Client, url: &str) -> Result<ImageMetadata, Str
     let response = response
         .error_for_status()
         .map_err(|err| format!("HTTP error: {}", err))?;
-    let bytes = response
-        .bytes()
+    let content_type = response
+        .headers()
+        .get(CONTENT_TYPE)
+        .and_then(|value| value.to_str().ok())
+        .unwrap_or("");
+    if !content_type.is_empty() && !content_type.starts_with("image/") {
+        return Err(format!("content type '{}' is not an image", content_type));
+    }
+
+    if let Some(length) = response.content_length()
+        && length > MAX_IMAGE_BYTES as u64
+    {
+        return Err(format!(
+            "image too large ({} bytes > {} bytes limit)",
+            length, MAX_IMAGE_BYTES
+        ));
+    }
+
+    let mut bytes = Vec::new();
+    let mut limited_reader = response.take((MAX_IMAGE_BYTES + 1) as u64);
+    limited_reader
+        .read_to_end(&mut bytes)
         .map_err(|err| format!("failed to read response body: {}", err))?;
+    if bytes.len() > MAX_IMAGE_BYTES {
+        return Err(format!(
+            "image exceeded {} bytes while downloading",
+            MAX_IMAGE_BYTES
+        ));
+    }
 
     let image = image::load_from_memory(&bytes)
         .map_err(|err| format!("unable to decode image bytes: {}", err))?;
@@ -302,6 +379,16 @@ fn build_output_path(input_path: &Path) -> PathBuf {
     input_path.with_file_name(format!("result_{}.xlsx", Uuid::new_v4()))
 }
 
+fn build_thread_pool(max_threads: usize) -> ThreadPool {
+    match ThreadPoolBuilder::new().num_threads(max_threads).build() {
+        Ok(pool) => pool,
+        Err(err) => {
+            eprintln!("Failed to build worker pool: {}", err);
+            std::process::exit(1);
+        }
+    }
+}
+
 fn write_results_excel(path: &Path, rows: &[OutputRow]) -> Result<(), String> {
     let mut workbook = Workbook::new();
     let worksheet = workbook.add_worksheet();