refactor: flatten IoCounter return value (#1253)

* refactor: rewrite io stats collection function result

* refactor: flatten IoCounters vector results

src/app/data_harvester/disks.rs

@@ -64,7 +64,8 @@ cfg_if! {
         pub fn get_io_usage() -> anyhow::Result<IoHarvest> {
             let mut io_hash: HashMap<String, Option<IoData>> = HashMap::new();
 
-            for io in io_stats()?.into_iter().flatten() {
+            // TODO: Maybe rewrite this to not do a result of vec of result...
+            for io in io_stats()?.into_iter() {
                 let mount_point = io.device_name().to_string_lossy();
 
                 io_hash.insert(

src/app/data_harvester/disks/freebsd.rs

@@ -29,6 +29,7 @@ struct FileSystem {
 }
 
 pub fn get_io_usage() -> error::Result<IoHarvest> {
+    // TODO: Should this (and other I/O collectors) fail fast? In general, should collection ever fail fast?
     #[allow(unused_mut)]
     let mut io_harvest: HashMap<String, Option<IoData>> =
         get_disk_info().map(|storage_system_information| {
@@ -43,7 +44,7 @@ pub fn get_io_usage() -> error::Result<IoHarvest> {
     {
         use crate::app::data_harvester::disks::zfs_io_counters;
         if let Ok(zfs_io) = zfs_io_counters::zfs_io_stats() {
-            for io in zfs_io.into_iter().flatten() {
+            for io in zfs_io.into_iter() {
                 let mount_point = io.device_name().to_string_lossy();
                 io_harvest.insert(
                     mount_point.to_string(),

src/app/data_harvester/disks/unix/linux/counters.rs

@@ -64,7 +64,7 @@ impl FromStr for IoCounters {
 }
 
 /// Returns an iterator of disk I/O stats. Pulls data from `/proc/diskstats`.
-pub fn io_stats() -> anyhow::Result<Vec<anyhow::Result<IoCounters>>> {
+pub fn io_stats() -> anyhow::Result<Vec<IoCounters>> {
     const PROC_DISKSTATS: &str = "/proc/diskstats";
 
     let mut results = vec![];
@@ -74,7 +74,9 @@ pub fn io_stats() -> anyhow::Result<Vec<anyhow::Result<IoCounters>>> {
     // This saves us from doing a string allocation on each iteration compared to `lines()`.
     while let Ok(bytes) = reader.read_line(&mut line) {
         if bytes > 0 {
-            results.push(IoCounters::from_str(&line));
+            if let Ok(counters) = IoCounters::from_str(&line) {
+                results.push(counters);
+            }
             line.clear();
         } else {
             break;

src/app/data_harvester/disks/unix/macos/counters.rs

@@ -44,6 +44,6 @@ fn get_device_io(device: io_kit::IoObject) -> anyhow::Result<IoCounters> {
 }
 
 /// Returns an iterator of disk I/O stats. Pulls data through IOKit.
-pub fn io_stats() -> anyhow::Result<Vec<anyhow::Result<IoCounters>>> {
-    Ok(get_disks()?.map(get_device_io).collect())
+pub fn io_stats() -> anyhow::Result<Vec<IoCounters>> {
+    Ok(get_disks()?.filter_map(|d| get_device_io(d).ok()).collect())
 }

src/app/data_harvester/disks/windows.rs

@@ -11,7 +11,7 @@ mod bindings;
 use bindings::*;
 
 /// Returns I/O stats.
-pub(crate) fn io_stats() -> anyhow::Result<Vec<anyhow::Result<IoCounters>>> {
+pub(crate) fn io_stats() -> anyhow::Result<Vec<IoCounters>> {
     let volume_io = all_volume_io()?;
 
     Ok(volume_io
@@ -23,6 +23,7 @@ pub(crate) fn io_stats() -> anyhow::Result<Vec<anyhow::Result<IoCounters>>> {
 
             IoCounters::new(name, read_bytes, write_bytes)
         })
+        .flatten()
         .collect::<Vec<_>>())
 }
 

src/app/data_harvester/disks/zfs_io_counters.rs

@@ -2,7 +2,7 @@ use crate::app::data_harvester::disks::IoCounters;
 
 /// Returns zpool I/O stats. Pulls data from `sysctl kstat.zfs.{POOL}.dataset.{objset-*}`
 #[cfg(target_os = "freebsd")]
-pub fn zfs_io_stats() -> anyhow::Result<Vec<anyhow::Result<IoCounters>>> {
+pub fn zfs_io_stats() -> anyhow::Result<Vec<IoCounters>> {
     use sysctl::Sysctl;
     let zfs_ctls: Vec<_> = sysctl::Ctl::new("kstat.zfs.")?
         .into_iter()
@@ -27,7 +27,7 @@ pub fn zfs_io_stats() -> anyhow::Result<Vec<anyhow::Result<IoCounters>>> {
         .collect();
 
     use itertools::Itertools;
-    let results: Vec<anyhow::Result<IoCounters>> = zfs_ctls
+    let results: Vec<IoCounters> = zfs_ctls
         .iter()
         .chunks(3)
         .into_iter()
@@ -50,7 +50,7 @@ pub fn zfs_io_stats() -> anyhow::Result<Vec<anyhow::Result<IoCounters>>> {
                     }
                 }
             }
-            Some(Ok(IoCounters::new(ds_name, nread, nwrite)))
+            Some(IoCounters::new(ds_name, nread, nwrite))
         })
         .collect();
     Ok(results)
@@ -58,7 +58,7 @@ pub fn zfs_io_stats() -> anyhow::Result<Vec<anyhow::Result<IoCounters>>> {
 
 /// Returns zpool I/O stats. Pulls data from `/proc/spl/kstat/zfs/*/objset-*`.
 #[cfg(target_os = "linux")]
-pub fn zfs_io_stats() -> anyhow::Result<Vec<anyhow::Result<IoCounters>>> {
+pub fn zfs_io_stats() -> anyhow::Result<Vec<IoCounters>> {
     if let Ok(zpools) = std::fs::read_dir("/proc/spl/kstat/zfs") {
         let zpools_vec: Vec<std::path::PathBuf> = zpools
             .filter_map(|e| {
@@ -90,7 +90,7 @@ pub fn zfs_io_stats() -> anyhow::Result<Vec<anyhow::Result<IoCounters>>> {
                                 })
                             })
                             .collect();
-                    let io_counters: Vec<anyhow::Result<IoCounters>> = datasets_vec
+                    let io_counters: Vec<IoCounters> = datasets_vec
                         .iter()
                         .filter_map(|ds| {
                             // get io-counter from each dataset
@@ -130,9 +130,9 @@ pub fn zfs_io_stats() -> anyhow::Result<Vec<anyhow::Result<IoCounters>>> {
                                         }
                                     }
                                 });
+
                                 let counter = IoCounters::new(name.to_owned(), read, write);
-                                //log::debug!("adding io counter for zfs {:?}", counter);
-                                Some(Ok(counter))
+                                Some(counter)
                             } else {
                                 None
                             }