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From: Dietmar Maurer <dietmar@proxmox.com>
To: pbs-devel@lists.proxmox.com
Subject: [pbs-devel] [PATCH proxmox-backup 11/15] proxmox-rrd: avoid % inside loop
Date: Wed, 13 Oct 2021 10:24:48 +0200	[thread overview]
Message-ID: <20211013082452.619406-12-dietmar@proxmox.com> (raw)
In-Reply-To: <20211013082452.619406-1-dietmar@proxmox.com>

Modulo is very slow, so we try to avoid it inside loops.
---
 proxmox-rrd/src/rrd.rs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/proxmox-rrd/src/rrd.rs b/proxmox-rrd/src/rrd.rs
index 7a9ce94a..54cb8b48 100644
--- a/proxmox-rrd/src/rrd.rs
+++ b/proxmox-rrd/src/rrd.rs
@@ -153,8 +153,7 @@ impl RRA {
             if let Some(v) = data[i] {
                 self.data[index] = v;
             }
-            index += 1;
-            if index >= self.data.len() { index = 0; }
+            index += 1; if index >= self.data.len() { index = 0; }
         }
         Ok(())
     }
@@ -171,7 +170,7 @@ impl RRA {
         let mut index = ((t/reso) % num_entries) as usize;
         for _ in 0..num_entries {
             t += reso;
-            index = (index + 1) % (num_entries as usize);
+            index += 1; if index >= self.data.len() { index = 0; }
             if t < min_time {
                 self.data[index] = f64::NAN;
             } else {
@@ -251,7 +250,8 @@ impl RRA {
                     list.push(Some(value));
                 }
             }
-            t += reso; index = (index + 1) % (num_entries as usize);
+            t += reso;
+            index += 1; if index >= self.data.len() { index = 0; }
         }
 
         (start, reso, list)
-- 
2.30.2





  parent reply	other threads:[~2021-10-13  8:25 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-13  8:24 [pbs-devel] [PATCH proxmox-backup 00/15] RRD database improvements Dietmar Maurer
2021-10-13  8:24 ` [pbs-devel] [PATCH proxmox-backup 01/15] proxmox-rrd: use a journal to reduce amount of bytes written Dietmar Maurer
2021-10-13  8:24 ` [pbs-devel] [PATCH proxmox-backup 02/15] RRD_CACHE: use a OnceCell instead of lazy_static Dietmar Maurer
2021-10-13  8:24 ` [pbs-devel] [PATCH proxmox-backup 03/15] proxmox-backup-proxy: use tokio::task::spawn_blocking instead of block_in_place Dietmar Maurer
2021-10-13  8:24 ` [pbs-devel] [PATCH proxmox-backup 04/15] proxmox-rrd: implement new CBOR based format Dietmar Maurer
2021-10-13  8:24 ` [pbs-devel] [PATCH proxmox-backup 05/15] proxmox-rrd: remove dependency to proxmox-rrd-api-types Dietmar Maurer
2021-10-13  8:24 ` [pbs-devel] [PATCH proxmox-backup 06/15] proxmox-rrd: extract_data: include values from current slot Dietmar Maurer
2021-10-13  8:24 ` [pbs-devel] [PATCH proxmox-backup 07/15] remove proxmox-rrd-api-types crate, s/RRDTimeFrameResolution/RRDTimeFrame/ Dietmar Maurer
2021-10-13  8:24 ` [pbs-devel] [PATCH proxmox-backup 08/15] proxmox-rrd: support CF::Last Dietmar Maurer
2021-10-13  8:24 ` [pbs-devel] [PATCH proxmox-backup 09/15] proxmox-rrd: split out load_rrd (cleanup) Dietmar Maurer
2021-10-13  8:24 ` [pbs-devel] [PATCH proxmox-backup 10/15] proxmox-rrd: add binary to create/manage rrd files Dietmar Maurer
2021-10-13  8:24 ` Dietmar Maurer [this message]
2021-10-13  8:24 ` [pbs-devel] [PATCH proxmox-backup 12/15] proxmox-rrd: new helper methods - slot() and slot_end_time() Dietmar Maurer
2021-10-13  8:24 ` [pbs-devel] [PATCH proxmox-backup 13/15] proxmox-rrd: protect against negative update time Dietmar Maurer
2021-10-13  8:24 ` [pbs-devel] [PATCH proxmox-backup 14/15] proxmox-rrd: rename last_counter to last_value Dietmar Maurer
2021-10-13  8:24 ` [pbs-devel] [PATCH proxmox-backup 15/15] proxmox-rrd: add more commands to the rrd cli tool Dietmar Maurer
2021-10-13 11:58 ` [pbs-devel] applied-series: [PATCH proxmox-backup 00/15] RRD database improvements Thomas Lamprecht

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