From 5b3dabf090029401859150e80db1531132aa87cf Mon Sep 17 00:00:00 2001
From: elkowar <5300871+elkowar@users.noreply.github.com>
Date: Sat, 17 Feb 2024 18:03:35 +0100
Subject: [PATCH] Fix logfiles growing indefinitely (fixes #750, #689, #1000)

---
 CHANGELOG.md             |  3 ++-
 crates/eww/src/paths.rs  | 24 ++++++++++++++-------
 crates/eww/src/server.rs | 46 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 64 insertions(+), 9 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index de2c30cac..a584870b1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -33,7 +33,8 @@ All notable changes to eww will be listed here, starting at changes since versio
 - Add `eww shell-completions` command, generating completion scripts for different shells
 
 ### Fixes
-- Fixed wrong values in `EWW_NET`
+- Fix wrong values in `EWW_NET`
+- Fix logfiles growing indefinitely
 
 ## [0.4.0] (04.09.2022)
 
diff --git a/crates/eww/src/paths.rs b/crates/eww/src/paths.rs
index 498bd8e52..9ad437d98 100644
--- a/crates/eww/src/paths.rs
+++ b/crates/eww/src/paths.rs
@@ -10,6 +10,7 @@ use anyhow::{bail, Result};
 #[derive(Debug, Clone)]
 pub struct EwwPaths {
     pub log_file: PathBuf,
+    pub log_dir: PathBuf,
     pub ipc_socket_file: PathBuf,
     pub config_dir: PathBuf,
 }
@@ -43,14 +44,17 @@ impl EwwPaths {
             log::warn!("The IPC socket file's absolute path exceeds 100 bytes, the socket may fail to create.");
         }
 
-        Ok(EwwPaths {
-            config_dir,
-            log_file: std::env::var("XDG_CACHE_HOME")
-                .map(PathBuf::from)
-                .unwrap_or_else(|_| PathBuf::from(std::env::var("HOME").unwrap()).join(".cache"))
-                .join(format!("eww_{}.log", daemon_id)),
-            ipc_socket_file,
-        })
+        let log_dir = std::env::var("XDG_CACHE_HOME")
+            .map(PathBuf::from)
+            .unwrap_or_else(|_| PathBuf::from(std::env::var("HOME").unwrap()).join(".cache"))
+            .join("eww");
+
+        if !log_dir.exists() {
+            log::info!("Creating log dir");
+            std::fs::create_dir_all(&log_dir)?;
+        }
+
+        Ok(EwwPaths { config_dir, log_file: log_dir.join(format!("eww_{}.log", daemon_id)), log_dir, ipc_socket_file })
     }
 
     pub fn default() -> Result<Self> {
@@ -66,6 +70,10 @@ impl EwwPaths {
         self.log_file.as_path()
     }
 
+    pub fn get_log_dir(&self) -> &Path {
+        self.log_dir.as_path()
+    }
+
     pub fn get_ipc_socket_file(&self) -> &Path {
         self.ipc_socket_file.as_path()
     }
diff --git a/crates/eww/src/server.rs b/crates/eww/src/server.rs
index 66cb4f640..be00db3af 100644
--- a/crates/eww/src/server.rs
+++ b/crates/eww/src/server.rs
@@ -11,6 +11,7 @@ use anyhow::{Context, Result};
 use std::{
     cell::RefCell,
     collections::{HashMap, HashSet},
+    io::Write,
     os::unix::io::AsRawFd,
     path::Path,
     rc::Rc,
@@ -41,6 +42,8 @@ pub fn initialize_server<B: DisplayBackend>(
         }
     };
 
+    cleanup_log_dir(paths.get_log_dir())?;
+
     if should_daemonize {
         let fork_result = do_detach(paths.get_log_file())?;
 
@@ -263,3 +266,46 @@ fn do_detach(log_file_path: impl AsRef<Path>) -> Result<ForkResult> {
 
     Ok(ForkResult::Child)
 }
+
+/// Ensure the log directory never grows larger than 100MB by deleting files older than 7 days,
+/// and truncating all other logfiles to 100MB.
+fn cleanup_log_dir(log_dir: impl AsRef<Path>) -> Result<()> {
+    // Find all files named "eww_*.log" in the log directory
+    let log_files = std::fs::read_dir(&log_dir)?
+        .filter_map(|entry| {
+            let entry = entry.ok()?;
+            let path = entry.path();
+            if let Some(file_name) = path.file_name() {
+                if file_name.to_string_lossy().starts_with("eww_") && file_name.to_string_lossy().ends_with(".log") {
+                    Some(path)
+                } else {
+                    None
+                }
+            } else {
+                None
+            }
+        })
+        .collect::<Vec<_>>();
+
+    for log_file in log_files {
+        // if the file is older than a week, delete it
+        if let Ok(metadata) = log_file.metadata() {
+            if metadata.modified()?.elapsed()?.as_secs() > 60 * 60 * 24 * 7 {
+                log::info!("Deleting old log file: {}", log_file.display());
+                std::fs::remove_file(&log_file)?;
+            } else {
+                // If the file is larger than 200MB, delete the start of it until it's 100MB or less.
+                let mut file = std::fs::OpenOptions::new().append(true).open(&log_file)?;
+                let file_size = file.metadata()?.len();
+                if file_size > 200_000_000 {
+                    let mut file_content = std::fs::read(&log_file)?;
+                    let bytes_to_remove = file_content.len().saturating_sub(100_000_000);
+                    file_content.drain(0..bytes_to_remove);
+                    file.set_len(0)?;
+                    file.write_all(&file_content)?;
+                }
+            }
+        }
+    }
+    Ok(())
+}