spider_lib/

stats.rs

//! Collects and stores various statistics about the crawler's operation.

use crate::error::SpiderError;
use std::{
    collections::HashMap,
    sync::{
        Arc, Mutex,
        atomic::{AtomicUsize, Ordering},
    },
    time::Instant,
};

// A snapshot of the current statistics, used for reporting.
// This avoids code duplication in the various export/display methods.
struct StatsSnapshot {
    requests_enqueued: usize,
    requests_sent: usize,
    requests_succeeded: usize,
    requests_failed: usize,
    requests_retried: usize,
    requests_dropped: usize,
    responses_received: usize,
    responses_from_cache: usize,
    total_bytes_downloaded: usize,
    items_scraped: usize,
    items_processed: usize,
    items_dropped_by_pipeline: usize,
    response_status_counts: HashMap<u16, usize>,
    elapsed_duration: std::time::Duration,
}

impl StatsSnapshot {
    fn formatted_duration(&self) -> String {
        format!("{:?}", self.elapsed_duration)
    }

    fn requests_per_second(&self) -> f64 {
        let total_seconds = self.elapsed_duration.as_secs();
        if total_seconds > 0 {
            self.requests_sent as f64 / total_seconds as f64
        } else {
            0.0
        }
    }

    fn responses_per_second(&self) -> f64 {
        let total_seconds = self.elapsed_duration.as_secs();
        if total_seconds > 0 {
            self.responses_received as f64 / total_seconds as f64
        } else {
            0.0
        }
    }

    fn items_per_second(&self) -> f64 {
        let total_seconds = self.elapsed_duration.as_secs();
        if total_seconds > 0 {
            self.items_scraped as f64 / total_seconds as f64
        } else {
            0.0
        }
    }

    fn formatted_bytes(&self) -> String {
        const KB: usize = 1024;
        const MB: usize = 1024 * KB;
        const GB: usize = 1024 * MB;

        if self.total_bytes_downloaded >= GB {
            format!("{:.2} GB", self.total_bytes_downloaded as f64 / GB as f64)
        } else if self.total_bytes_downloaded >= MB {
            format!("{:.2} MB", self.total_bytes_downloaded as f64 / MB as f64)
        } else if self.total_bytes_downloaded >= KB {
            format!("{:.2} KB", self.total_bytes_downloaded as f64 / KB as f64)
        } else {
            format!("{} B", self.total_bytes_downloaded)
        }
    }
}

/// Collects and stores various statistics about the crawler's operation.
#[derive(Debug, Serialize)]
pub struct StatCollector {
    // Crawl-related metrics
    #[serde(skip)]
    pub start_time: Instant,

    // Request-related metrics
    pub requests_enqueued: AtomicUsize,
    pub requests_sent: AtomicUsize,
    pub requests_succeeded: AtomicUsize,
    pub requests_failed: AtomicUsize,
    pub requests_retried: AtomicUsize,
    pub requests_dropped: AtomicUsize,

    // Response-related metrics
    pub responses_received: AtomicUsize,
    pub responses_from_cache: AtomicUsize,
    pub response_status_counts: Arc<Mutex<HashMap<u16, usize>>>, // e.g., 200, 404, 500
    pub total_bytes_downloaded: AtomicUsize,

    // Add more advanced response time metrics if needed (e.g., histograms)

    // Item-related metrics
    pub items_scraped: AtomicUsize,
    pub items_processed: AtomicUsize,
    pub items_dropped_by_pipeline: AtomicUsize,
}

impl StatCollector {
    /// Creates a new `StatCollector` with all counters initialized to zero.
    pub(crate) fn new() -> Self {
        StatCollector {
            start_time: Instant::now(),
            requests_enqueued: AtomicUsize::new(0),
            requests_sent: AtomicUsize::new(0),
            requests_succeeded: AtomicUsize::new(0),
            requests_failed: AtomicUsize::new(0),
            requests_retried: AtomicUsize::new(0),
            requests_dropped: AtomicUsize::new(0),
            responses_received: AtomicUsize::new(0),
            responses_from_cache: AtomicUsize::new(0),
            response_status_counts: Arc::new(Mutex::new(HashMap::new())),
            total_bytes_downloaded: AtomicUsize::new(0),
            items_scraped: AtomicUsize::new(0),
            items_processed: AtomicUsize::new(0),
            items_dropped_by_pipeline: AtomicUsize::new(0),
        }
    }

    /// Creates a snapshot of the current statistics.
    /// This is the single source of truth for all presentation logic.
    fn snapshot(&self) -> StatsSnapshot {
        let status_counts_guard = self.response_status_counts.lock().unwrap();
        let status_counts: HashMap<u16, usize> = status_counts_guard.clone();

        StatsSnapshot {
            requests_enqueued: self.requests_enqueued.load(Ordering::SeqCst),
            requests_sent: self.requests_sent.load(Ordering::SeqCst),
            requests_succeeded: self.requests_succeeded.load(Ordering::SeqCst),
            requests_failed: self.requests_failed.load(Ordering::SeqCst),
            requests_retried: self.requests_retried.load(Ordering::SeqCst),
            requests_dropped: self.requests_dropped.load(Ordering::SeqCst),
            responses_received: self.responses_received.load(Ordering::SeqCst),
            responses_from_cache: self.responses_from_cache.load(Ordering::SeqCst),
            total_bytes_downloaded: self.total_bytes_downloaded.load(Ordering::SeqCst),
            items_scraped: self.items_scraped.load(Ordering::SeqCst),
            items_processed: self.items_processed.load(Ordering::SeqCst),
            items_dropped_by_pipeline: self.items_dropped_by_pipeline.load(Ordering::SeqCst),
            response_status_counts: status_counts,
            elapsed_duration: self.start_time.elapsed(),
        }
    }

    /// Increments the count of enqueued requests.
    pub(crate) fn increment_requests_enqueued(&self) {
        self.requests_enqueued.fetch_add(1, Ordering::SeqCst);
    }

    /// Increments the count of sent requests.
    pub(crate) fn increment_requests_sent(&self) {
        self.requests_sent.fetch_add(1, Ordering::SeqCst);
    }

    /// Increments the count of successful requests.
    pub(crate) fn increment_requests_succeeded(&self) {
        self.requests_succeeded.fetch_add(1, Ordering::SeqCst);
    }

    /// Increments the count of failed requests.
    pub(crate) fn increment_requests_failed(&self) {
        self.requests_failed.fetch_add(1, Ordering::SeqCst);
    }

    /// Increments the count of retried requests.
    pub(crate) fn increment_requests_retried(&self) {
        self.requests_retried.fetch_add(1, Ordering::SeqCst);
    }

    /// Increments the count of dropped requests.
    pub(crate) fn increment_requests_dropped(&self) {
        self.requests_dropped.fetch_add(1, Ordering::SeqCst);
    }

    /// Increments the count of received responses.
    pub(crate) fn increment_responses_received(&self) {
        self.responses_received.fetch_add(1, Ordering::SeqCst);
    }

    /// Increments the count of responses served from cache.
    pub(crate) fn increment_responses_from_cache(&self) {
        self.responses_from_cache.fetch_add(1, Ordering::SeqCst);
    }

    /// Records a response status code.
    pub(crate) fn record_response_status(&self, status_code: u16) {
        let mut counts = self.response_status_counts.lock().unwrap();
        *counts.entry(status_code).or_insert(0) += 1;
    }

    /// Adds to the total bytes downloaded.
    pub(crate) fn add_bytes_downloaded(&self, bytes: usize) {
        self.total_bytes_downloaded
            .fetch_add(bytes, Ordering::SeqCst);
    }

    /// Increments the count of scraped items.
    pub(crate) fn increment_items_scraped(&self) {
        self.items_scraped.fetch_add(1, Ordering::SeqCst);
    }

    /// Increments the count of processed items.
    pub(crate) fn increment_items_processed(&self) {
        self.items_processed.fetch_add(1, Ordering::SeqCst);
    }

    /// Increments the count of items dropped by pipelines.
    pub(crate) fn increment_items_dropped_by_pipeline(&self) {
        self.items_dropped_by_pipeline
            .fetch_add(1, Ordering::SeqCst);
    }

    /// Converts the snapshot into a JSON string.
    pub fn to_json_string(&self) -> Result<String, SpiderError> {
        Ok(serde_json::to_string(self)?)
    }

    /// Converts the snapshot into a pretty-printed JSON string.
    pub fn to_json_string_pretty(&self) -> Result<String, SpiderError> {
        Ok(serde_json::to_string_pretty(self)?)
    }

    /// Exports the current statistics to a Markdown formatted string.
    pub fn to_markdown_string(&self) -> String {
        let snapshot = self.snapshot();

        let status_codes_list: String = snapshot
            .response_status_counts
            .iter()
            .map(|(code, count)| format!("- **{}**: {}", code, count))
            .collect::<Vec<String>>()
            .join("\n");
        let status_codes_output = if status_codes_list.is_empty() {
            "N/A".to_string()
        } else {
            status_codes_list
        };

        format!(
            r#"# Crawl Statistics Report

- **Duration**: {}
- **Average Speed**: {:.2} req/s, {:.2} resp/s, {:.2} item/s

## Requests
| Metric     | Count |
|------------|-------|
| Enqueued   | {}     |
| Sent       | {}     |
| Succeeded  | {}     |
| Failed     | {}     |
| Retried    | {}     |
| Dropped    | {}     |

## Responses
| Metric     | Count |
|------------|-------|
| Received   | {}     |
 From Cache | {}     |
| Downloaded | {}     |

## Items
| Metric     | Count |
|------------|--------|
| Scraped    | {}     |
| Processed  | {}     |
| Dropped    | {}     |

## Status Codes
{}
"#,
            snapshot.formatted_duration(),
            snapshot.requests_per_second(),
            snapshot.responses_per_second(),
            snapshot.items_per_second(),
            snapshot.requests_enqueued,
            snapshot.requests_sent,
            snapshot.requests_succeeded,
            snapshot.requests_failed,
            snapshot.requests_retried,
            snapshot.requests_dropped,
            snapshot.responses_received,
            snapshot.responses_from_cache,
            snapshot.formatted_bytes(),
            snapshot.items_scraped,
            snapshot.items_processed,
            snapshot.items_dropped_by_pipeline,
            status_codes_output
        )
    }
}

impl Default for StatCollector {
    fn default() -> Self {
        Self::new()
    }
}

use serde::Serialize;

impl std::fmt::Display for StatCollector {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        let snapshot = self.snapshot();

        writeln!(f, "\nCrawl Statistics")?;
        writeln!(f, "----------------")?;
        writeln!(f, "  duration : {}", snapshot.formatted_duration())?;
        writeln!(
            f,
            "  speed    : req/s: {:.2}, resp/s: {:.2}, item/s: {:.2}",
            snapshot.requests_per_second(),
            snapshot.responses_per_second(),
            snapshot.items_per_second()
        )?;
        writeln!(
            f,
            "  requests : enqueued: {}, sent: {}, ok: {}, fail: {}, retry: {}, drop: {}",
            snapshot.requests_enqueued,
            snapshot.requests_sent,
            snapshot.requests_succeeded,
            snapshot.requests_failed,
            snapshot.requests_retried,
            snapshot.requests_dropped
        )?;
        writeln!(
            f,
            "  response : received: {}, from_cache: {}, downloaded: {}",
            snapshot.responses_received,
            snapshot.responses_from_cache,
            snapshot.formatted_bytes()
        )?;
        writeln!(
            f,
            "  items    : scraped: {}, processed: {}, dropped: {}",
            snapshot.items_scraped, snapshot.items_processed, snapshot.items_dropped_by_pipeline
        )?;

        let status_string = if snapshot.response_status_counts.is_empty() {
            "none".to_string()
        } else {
            snapshot
                .response_status_counts
                .iter()
                .map(|(code, count)| format!("{}: {}", code, count))
                .collect::<Vec<String>>()
                .join(", ")
        };

        writeln!(f, "  status   : {}\n", status_string)
    }
}