refactor: Remove ps calls

Removes and refactor ps calls that... should have not been there in the first place.

10 files changed, 151 insertions, 137 deletions

diff --git a/.vscode/settings.json b/.vscode/settings.json
index 5074ded4..4ede05b1 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -13,6 +13,7 @@
         "WASD",
         "Wojnarowski",
         "andys",
+        "cmdline",
         "crossterm",
         "curr",
         "czvf",
@@ -29,9 +30,12 @@
         "paren",
         "processthreadsapi",
         "regexes",
+        "rsplitn",
         "rustfmt",
         "shilangyu",
         "softirq",
+        "splitn",
+        "statm",
         "stime",
         "subwidget",
         "sysconf",
@@ -43,6 +47,7 @@
         "use curr usage",
         "utime",
         "virt",
+        "vsize",
         "whitespaces",
         "winapi",
         "winnt",
diff --git a/Cargo.lock b/Cargo.lock
index 4d9be6aa..6b8219ca 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -145,6 +145,7 @@ dependencies = [
  "heim",
  "itertools",
  "lazy_static",
+ "libc",
  "log",
  "predicates",
  "regex",
diff --git a/Cargo.toml b/Cargo.toml
index 7a908c72..4ba087e8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -40,7 +40,7 @@ backtrace = "0.3"
 serde = {version = "1.0", features = ["derive"] }
 unicode-segmentation = "1.6.0"
 unicode-width = "0.1.7"
-# libc = "0.2.74"
+libc = "0.2.74"
 # tui = {version = "0.10.0", features = ["crossterm"], default-features = false, git = "https://github.com/fdehau/tui-rs.git"}
 tui = {version = "0.9.5", features = ["crossterm"], default-features = false }
 
diff --git a/src/app/data_harvester.rs b/src/app/data_harvester.rs
index e04d8354..042638b0 100644
--- a/src/app/data_harvester.rs
+++ b/src/app/data_harvester.rs
@@ -72,7 +72,7 @@ pub struct DataCollector {
     pub data: Data,
     sys: System,
     #[cfg(target_os = "linux")]
-    prev_pid_stats: HashMap<u32, processes::PrevProcDetails>,
+    pid_mapping: HashMap<u32, processes::PrevProcDetails>,
     #[cfg(target_os = "linux")]
     prev_idle: f64,
     #[cfg(target_os = "linux")]
@@ -87,7 +87,7 @@ pub struct DataCollector {
     widgets_to_harvest: UsedWidgets,
     battery_manager: Option<Manager>,
     battery_list: Option<Vec<Battery>>,
-    // page_file_size_kb: u64,
+    page_file_size_kb: u64,
 }
 
 impl Default for DataCollector {
@@ -96,7 +96,7 @@ impl Default for DataCollector {
             data: Data::default(),
             sys: System::new_all(),
             #[cfg(target_os = "linux")]
-            prev_pid_stats: HashMap::new(),
+            pid_mapping: HashMap::new(),
             #[cfg(target_os = "linux")]
             prev_idle: 0_f64,
             #[cfg(target_os = "linux")]
@@ -111,11 +111,15 @@ impl Default for DataCollector {
             widgets_to_harvest: UsedWidgets::default(),
             battery_manager: None,
             battery_list: None,
-            // page_file_size_kb: if cfg!(target_os = "linux") {
-            //     unsafe { libc::sysconf(libc::_SC_PAGESIZE) as u64 / 1024 }
-            // } else {
-            //     0
-            // },
+            page_file_size_kb: {
+                #[cfg(target_os = "linux")]
+                unsafe {
+                    libc::sysconf(libc::_SC_PAGESIZE) as u64 / 1024
+                }
+
+                #[cfg(not(target_os = "linux"))]
+                0
+            },
         }
     }
 }
@@ -201,12 +205,13 @@ impl DataCollector {
                     processes::linux_get_processes_list(
                         &mut self.prev_idle,
                         &mut self.prev_non_idle,
-                        &mut self.prev_pid_stats,
+                        &mut self.pid_mapping,
                         self.use_current_cpu_total,
                         current_instant
                             .duration_since(self.last_collection_time)
                             .as_secs(),
                         self.mem_total_kb,
+                        self.page_file_size_kb,
                     )
                 }
                 #[cfg(not(target_os = "linux"))]
diff --git a/src/app/data_harvester/processes.rs b/src/app/data_harvester/processes.rs
index 3877c35a..8bf23795 100644
--- a/src/app/data_harvester/processes.rs
+++ b/src/app/data_harvester/processes.rs
@@ -2,12 +2,10 @@ use std::path::PathBuf;
 use sysinfo::ProcessStatus;
 
 #[cfg(target_os = "linux")]
-use crate::utils::error;
+use crate::utils::error::{self, BottomError};
+
 #[cfg(target_os = "linux")]
-use std::{
-    collections::{hash_map::RandomState, HashMap},
-    process::Command,
-};
+use std::collections::{hash_map::RandomState, HashMap};
 
 #[cfg(not(target_os = "linux"))]
 use sysinfo::{ProcessExt, ProcessorExt, System, SystemExt};
@@ -66,7 +64,7 @@ pub struct ProcessHarvest {
     // pub rss_kb: u64,
     // pub virt_kb: u64,
     pub name: String,
-    pub path: String,
+    pub command: String,
     pub read_bytes_per_sec: u64,
     pub write_bytes_per_sec: u64,
     pub total_read_bytes: u64,
@@ -81,17 +79,21 @@ pub struct PrevProcDetails {
     pub total_write_bytes: u64,
     pub cpu_time: f64,
     pub proc_stat_path: PathBuf,
+    // pub proc_statm_path: PathBuf,
     pub proc_exe_path: PathBuf,
     pub proc_io_path: PathBuf,
+    pub proc_cmdline_path: PathBuf,
+    pub just_read: bool,
 }
 
 impl PrevProcDetails {
     pub fn new(pid: u32) -> Self {
-        let pid_string = pid.to_string();
         PrevProcDetails {
-            proc_io_path: PathBuf::from(format!("/proc/{}/io", pid_string)),
-            proc_exe_path: PathBuf::from(format!("/proc/{}/exe", pid_string)),
-            proc_stat_path: PathBuf::from(format!("/proc/{}/stat", pid_string)),
+            proc_io_path: PathBuf::from(format!("/proc/{}/io", pid)),
+            proc_exe_path: PathBuf::from(format!("/proc/{}/exe", pid)),
+            proc_stat_path: PathBuf::from(format!("/proc/{}/stat", pid)),
+            // proc_statm_path: PathBuf::from(format!("/proc/{}/statm", pid)),
+            proc_cmdline_path: PathBuf::from(format!("/proc/{}/cmdline", pid)),
             ..PrevProcDetails::default()
         }
     }
@@ -172,23 +174,32 @@ fn get_process_io(path: &PathBuf) -> std::io::Result<String> {
 }
 
 #[cfg(target_os = "linux")]
-fn get_linux_process_io_usage(io_stats: &[&str]) -> (u64, u64) {
+fn get_linux_process_io_usage(stat: &[&str]) -> (u64, u64) {
     // Represents read_bytes and write_bytes
     (
-        io_stats[9].parse::<u64>().unwrap_or(0),
-        io_stats[11].parse::<u64>().unwrap_or(0),
+        stat[9].parse::<u64>().unwrap_or(0),
+        stat[11].parse::<u64>().unwrap_or(0),
+    )
+}
+
+#[cfg(target_os = "linux")]
+fn get_linux_process_vsize_rss(stat: &[&str]) -> (u64, u64) {
+    // Represents vsize and rss (bytes and page numbers respectively)
+    (
+        stat[20].parse::<u64>().unwrap_or(0),
+        stat[21].parse::<u64>().unwrap_or(0),
     )
 }
 
 #[cfg(target_os = "linux")]
-fn get_process_stats(path: &PathBuf) -> std::io::Result<String> {
+fn read_path_contents(path: &PathBuf) -> std::io::Result<String> {
     Ok(std::fs::read_to_string(path)?)
 }
 
 #[cfg(target_os = "linux")]
-fn get_linux_process_state(proc_stats: &[&str]) -> (char, String) {
+fn get_linux_process_state(stat: &[&str]) -> (char, String) {
     // The -2 offset is because of us cutting off name + pid
-    if let Some(first_char) = proc_stats[0].chars().collect::<Vec<char>>().first() {
+    if let Some(first_char) = stat[0].chars().collect::<Vec<char>>().first() {
         (
             *first_char,
             ProcessStatus::from(*first_char).to_string().to_string(),
@@ -201,103 +212,98 @@ fn get_linux_process_state(proc_stats: &[&str]) -> (char, String) {
 /// Note that cpu_fraction should be represented WITHOUT the x100 factor!
 #[cfg(target_os = "linux")]
 fn get_linux_cpu_usage(
-    proc_stats: &[&str], cpu_usage: f64, cpu_fraction: f64, before_proc_val: f64,
+    proc_stats: &[&str], cpu_usage: f64, cpu_fraction: f64, prev_proc_val: &mut f64,
     use_current_cpu_total: bool,
-) -> std::io::Result<(f64, f64)> {
-    fn get_process_cpu_stats(stats: &[&str]) -> f64 {
-        // utime + stime (matches top), the -2 offset is because of us cutting off name + pid
-        stats[11].parse::<f64>().unwrap_or(0_f64) + stats[12].parse::<f64>().unwrap_or(0_f64)
+) -> std::io::Result<f64> {
+    fn get_process_cpu_stats(stat: &[&str]) -> f64 {
+        // utime + stime (matches top), the -2 offset is because of us cutting off name + pid (normally 13, 14)
+        stat[11].parse::<f64>().unwrap_or(0_f64) + stat[12].parse::<f64>().unwrap_or(0_f64)
     }
 
     // Based heavily on https://stackoverflow.com/a/23376195 and https://stackoverflow.com/a/1424556
-    let after_proc_val = get_process_cpu_stats(&proc_stats);
+    let new_proc_val = get_process_cpu_stats(&proc_stats);
 
     if cpu_usage == 0.0 {
-        Ok((0_f64, after_proc_val))
+        Ok(0_f64)
     } else if use_current_cpu_total {
-        Ok((
-            (after_proc_val - before_proc_val) / cpu_usage * 100_f64,
-            after_proc_val,
-        ))
+        let res = Ok((new_proc_val - *prev_proc_val) / cpu_usage * 100_f64);
+        *prev_proc_val = new_proc_val;
+        res
     } else {
-        Ok((
-            (after_proc_val - before_proc_val) / cpu_usage * 100_f64 * cpu_fraction,
-            after_proc_val,
-        ))
+        let res = Ok((new_proc_val - *prev_proc_val) / cpu_usage * 100_f64 * cpu_fraction);
+        *prev_proc_val = new_proc_val;
+        res
     }
 }
 
 #[allow(clippy::too_many_arguments)]
 #[cfg(target_os = "linux")]
-fn convert_ps<S: core::hash::BuildHasher>(
-    process: &str, cpu_usage: f64, cpu_fraction: f64,
-    prev_pid_stats: &mut HashMap<u32, PrevProcDetails, S>,
-    new_pid_stats: &mut HashMap<u32, PrevProcDetails, S>, use_current_cpu_total: bool,
-    time_difference_in_secs: u64, mem_total_kb: u64,
-) -> std::io::Result<ProcessHarvest> {
-    let pid = (&process[..10])
-        .trim()
-        .to_string()
-        .parse::<u32>()
-        .unwrap_or(0);
-    let name = (&process[11..111]).trim().to_string();
-    let mem_usage_percent = (&process[112..116])
-        .trim()
-        .to_string()
-        .parse::<f64>()
-        .unwrap_or(0_f64);
-    let path = (&process[117..]).trim().to_string();
-
-    let mut new_pid_stat = if let Some(prev_proc_stats) = prev_pid_stats.remove(&pid) {
-        prev_proc_stats
-    } else {
-        PrevProcDetails::new(pid)
-    };
-
-    let (cpu_usage_percent, process_state_char, process_state) =
-        if let Ok(stat_results) = get_process_stats(&new_pid_stat.proc_stat_path) {
-            if let Some(tmp_split) = stat_results.split(')').collect::<Vec<_>>().last() {
-                let proc_stats = tmp_split.split_whitespace().collect::<Vec<&str>>();
-                let (process_state_char, process_state) = get_linux_process_state(&proc_stats);
-
-                let (cpu_usage_percent, after_proc_val) = get_linux_cpu_usage(
-                    &proc_stats,
-                    cpu_usage,
-                    cpu_fraction,
-                    new_pid_stat.cpu_time,
-                    use_current_cpu_total,
-                )?;
-                new_pid_stat.cpu_time = after_proc_val;
-
-                (cpu_usage_percent, process_state_char, process_state)
-            } else {
-                (0.0, '?', String::new())
-            }
+fn read_proc<S: core::hash::BuildHasher>(
+    pid: u32, cpu_usage: f64, cpu_fraction: f64,
+    pid_mapping: &mut HashMap<u32, PrevProcDetails, S>, use_current_cpu_total: bool,
+    time_difference_in_secs: u64, mem_total_kb: u64, page_file_kb: u64,
+) -> error::Result<ProcessHarvest> {
+    let pid_stat = pid_mapping
+        .entry(pid)
+        .or_insert_with(|| PrevProcDetails::new(pid));
+    let stat_results = read_path_contents(&pid_stat.proc_stat_path)?;
+    let name = stat_results
+        .splitn(2, '(')
+        .collect::<Vec<_>>()
+        .last()
+        .ok_or(BottomError::MinorError())?
+        .rsplitn(2, ')')
+        .collect::<Vec<_>>()
+        .last()
+        .ok_or(BottomError::MinorError())?
+        .to_string();
+    let command = {
+        let cmd = read_path_contents(&pid_stat.proc_cmdline_path)?;
+        if cmd.trim().is_empty() {
+            format!("[{}]", name)
         } else {
-            (0.0, '?', String::new())
-        };
+            cmd
+        }
+    };
+    let stat = stat_results
+        .split(')')
+        .collect::<Vec<_>>()
+        .last()
+        .ok_or(BottomError::MinorError())?
+        .split_whitespace()
+        .collect::<Vec<&str>>();
+    let (process_state_char, process_state) = get_linux_process_state(&stat);
+    let cpu_usage_percent = get_linux_cpu_usage(
+        &stat,
+        cpu_usage,
+        cpu_fraction,
+        &mut pid_stat.cpu_time,
+        use_current_cpu_total,
+    )?;
+    let (_vsize, rss) = get_linux_process_vsize_rss(&stat);
+    let mem_usage_kb = rss * page_file_kb;
+    let mem_usage_percent = mem_usage_kb as f64 * 100.0 / mem_total_kb as f64;
 
     // This can fail if permission is denied!
     let (total_read_bytes, total_write_bytes, read_bytes_per_sec, write_bytes_per_sec) =
-        if let Ok(io_results) = get_process_io(&new_pid_stat.proc_io_path) {
+        if let Ok(io_results) = get_process_io(&pid_stat.proc_io_path) {
             let io_stats = io_results.split_whitespace().collect::<Vec<&str>>();
 
             let (total_read_bytes, total_write_bytes) = get_linux_process_io_usage(&io_stats);
             let read_bytes_per_sec = if time_difference_in_secs == 0 {
                 0
             } else {
-                total_read_bytes.saturating_sub(new_pid_stat.total_read_bytes)
-                    / time_difference_in_secs
+                total_read_bytes.saturating_sub(pid_stat.total_read_bytes) / time_difference_in_secs
             };
             let write_bytes_per_sec = if time_difference_in_secs == 0 {
                 0
             } else {
-                total_write_bytes.saturating_sub(new_pid_stat.total_write_bytes)
+                total_write_bytes.saturating_sub(pid_stat.total_write_bytes)
                     / time_difference_in_secs
             };
 
-            new_pid_stat.total_read_bytes = total_read_bytes;
-            new_pid_stat.total_write_bytes = total_write_bytes;
+            pid_stat.total_read_bytes = total_read_bytes;
+            pid_stat.total_write_bytes = total_write_bytes;
 
             (
                 total_read_bytes,
@@ -309,15 +315,12 @@ fn convert_ps<S: core::hash::BuildHasher>(
             (0, 0, 0, 0)
         };
 
-    new_pid_stats.insert(pid, new_pid_stat);
-
-    // TODO: Is there a way to re-use these stats so I don't have to do so many syscalls?
     Ok(ProcessHarvest {
         pid,
         name,
-        path,
+        command,
         mem_usage_percent,
-        mem_usage_kb: (mem_usage_percent * mem_total_kb as f64 / 100.0) as u64,
+        mem_usage_kb,
         cpu_usage_percent,
         total_read_bytes,
         total_write_bytes,
@@ -331,45 +334,35 @@ fn convert_ps<S: core::hash::BuildHasher>(
 #[cfg(target_os = "linux")]
 pub fn linux_get_processes_list(
     prev_idle: &mut f64, prev_non_idle: &mut f64,
-    prev_pid_stats: &mut HashMap<u32, PrevProcDetails, RandomState>, use_current_cpu_total: bool,
-    time_difference_in_secs: u64, mem_total_kb: u64,
+    pid_mapping: &mut HashMap<u32, PrevProcDetails, RandomState>, use_current_cpu_total: bool,
+    time_difference_in_secs: u64, mem_total_kb: u64, page_file_kb: u64,
 ) -> crate::utils::error::Result<Vec<ProcessHarvest>> {
-    let ps_result = Command::new("ps")
-        .args(&["-axo", "pid:10,comm:100,%mem:5,args:100", "--noheader"])
-        .output()?;
-    let ps_stdout = String::from_utf8_lossy(&ps_result.stdout);
-    let split_string = ps_stdout.split('\n');
     if let Ok((cpu_usage, cpu_fraction)) = cpu_usage_calculation(prev_idle, prev_non_idle) {
-        let process_list = split_string.collect::<Vec<&str>>();
-        let mut new_pid_stats = HashMap::new();
-
-        let process_vector: Vec<ProcessHarvest> = process_list
-            .iter()
-            .filter_map(|process| {
-                if process.trim().is_empty() {
-                    None
-                } else if let Ok(process_object) = convert_ps(
-                    process,
-                    cpu_usage,
-                    cpu_fraction,
-                    prev_pid_stats,
-                    &mut new_pid_stats,
-                    use_current_cpu_total,
-                    time_difference_in_secs,
-                    mem_total_kb,
-                ) {
-                    if !process_object.name.is_empty() {
-                        Some(process_object)
-                    } else {
-                        None
+        let process_vector: Vec<ProcessHarvest> = std::fs::read_dir("/proc")?
+            .filter_map(|dir| {
+                if let Ok(dir) = dir {
+                    let pid = dir.file_name().to_string_lossy().trim().parse::<u32>();
+                    if let Ok(pid) = pid {
+                        // I skip checking if the path is also a directory, it's not needed I think?
+                        if let Ok(process_object) = read_proc(
+                            pid,
+                            cpu_usage,
+                            cpu_fraction,
+                            pid_mapping,
+                            use_current_cpu_total,
+                            time_difference_in_secs,
+                            mem_total_kb,
+                            page_file_kb,
+                        ) {
+                            return Some(process_object);
+                        }
                     }
-                } else {
-                    None
                 }
+
+                None
             })
             .collect();
 
-        *prev_pid_stats = new_pid_stats;
         Ok(process_vector)
     } else {
         Ok(Vec::new())
@@ -405,12 +398,12 @@ pub fn windows_macos_get_processes_list(
         } else {
             process_val.name().to_string()
         };
-        let path = {
-            let path = process_val.cmd().join(" ");
-            if path.is_empty() {
+        let command = {
+            let command = process_val.cmd().join(" ");
+            if command.is_empty() {
                 name.to_string()
             } else {
-                path
+                command
             }
         };
 
@@ -430,7 +423,7 @@ pub fn windows_macos_get_processes_list(
         process_vector.push(ProcessHarvest {
             pid: process_val.pid() as u32,
             name,
-            path,
+            command,
             mem_usage_percent: if mem_total_kb > 0 {
                 process_val.memory() as f64 * 100.0 / mem_total_kb as f64
             } else {
diff --git a/src/app/process_killer.rs b/src/app/process_killer.rs
index 05faf945..68754c39 100644
--- a/src/app/process_killer.rs
+++ b/src/app/process_killer.rs
@@ -35,6 +35,7 @@ impl Process {
 /// Kills a process, given a PID.
 pub fn kill_process_given_pid(pid: u32) -> crate::utils::error::Result<()> {
     if cfg!(target_os = "linux") || cfg!(target_os = "macos") {
+        // FIXME: Use libc instead of a command...
         let output = Command::new("kill").arg(pid.to_string()).output()?;
         if !(output.status).success() {
             return Err(BottomError::GenericError(
diff --git a/src/app/query.rs b/src/app/query.rs
index 41d18272..2a6d4cb4 100644
--- a/src/app/query.rs
+++ b/src/app/query.rs
@@ -674,6 +674,7 @@ impl Prefix {
                     process.cpu_percent_usage,
                     numerical_query.value,
                 ),
+                // FIXME: This doesn't work with mem values!
                 PrefixType::Mem => matches_condition(
                     &numerical_query.condition,
                     process.mem_percent_usage,
diff --git a/src/data_conversion.rs b/src/data_conversion.rs
index 0bf19d0b..d62b723b 100644
--- a/src/data_conversion.rs
+++ b/src/data_conversion.rs
@@ -398,7 +398,7 @@ pub fn convert_process_data(
                     pid: process.pid,
                     name: match name_type {
                         ProcessNamingType::Name => process.name.to_string(),
-                        ProcessNamingType::Path => process.path.to_string(),
+                        ProcessNamingType::Path => process.command.to_string(),
                     },
                     cpu_percent_usage: process.cpu_usage_percent,
                     mem_percent_usage: process.mem_usage_percent,
@@ -425,7 +425,7 @@ pub fn convert_process_data(
                 let entry = grouped_hashmap
                     .entry(match name_type {
                         ProcessNamingType::Name => process.name.to_string(),
-                        ProcessNamingType::Path => process.path.to_string(),
+                        ProcessNamingType::Path => process.command.to_string(),
                     })
                     .or_insert(SingleProcessData {
                         pid: process.pid,
diff --git a/src/lib.rs b/src/lib.rs
index 53d7430b..6929e095 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,8 @@
+#![warn(rust_2018_idioms)]
+#[allow(unused_imports)]
+#[macro_use]
+extern crate log;
+
 use std::{
     boxed::Box,
     io::{stdout, Write},
diff --git a/src/utils/error.rs b/src/utils/error.rs
index 5069cc78..4c607ebe 100644
--- a/src/utils/error.rs
+++ b/src/utils/error.rs
@@ -24,6 +24,8 @@ pub enum BottomError {
     ConversionError(String),
     /// An error to represent errors with querying.
     QueryError(Cow<'static, str>),
+    /// An error that just signifies something minor went wrong; no message.
+    MinorError(),
 }
 
 impl std::fmt::Display for BottomError {
@@ -50,6 +52,7 @@ impl std::fmt::Display for BottomError {
                 write!(f, "unable to convert: {}", message)
             }
             BottomError::QueryError(ref message) => write!(f, "{}", message),
+            BottomError::MinorError() => write!(f, "Minor error."),
         }
     }
 }