From: Dominik Csapak <d.csapak@proxmox.com>
Date: Thu, 30 Jul 2020 09:04:10 +0000 (+0200)
Subject: run_command: improve performance for logging and long lines
X-Git-Url: https://git.proxmox.com/?p=pve-common.git;a=commitdiff_plain;h=cb9db10c1a9855cf40ff13e81f9dd97d6a9b2698

run_command: improve performance for logging and long lines

to call out/err/logfunc with each line, we search for a newline and call
outfunc/logfunc with everything before that

since we do a select/read (with 4096 size) in a loop, this means
that if we have very long lines, we search for a newline in an
ever growing buffer (for which we know does not contain a newline)

so instead, only search the new data for newlines

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
---

diff --git a/src/PVE/Tools.pm b/src/PVE/Tools.pm
index 5d53127..d9c69e3 100644
--- a/src/PVE/Tools.pm
+++ b/src/PVE/Tools.pm
@@ -497,12 +497,13 @@ sub run_command {
 		if ($h eq $reader) {
 		    if ($outfunc || $logfunc) {
 			eval {
-			    $outlog .= $buf;
-			    while ($outlog =~ s/^([^\010\r\n]*)(\r|\n|(\010)+|\r\n)//s) {
-				my $line = $1;
+			    while ($buf =~ s/^([^\010\r\n]*)(\r|\n|(\010)+|\r\n)//) {
+				my $line = $outlog . $1;
+				$outlog = '';
 				&$outfunc($line) if $outfunc;
 				&$logfunc($line) if $logfunc;
 			    }
+			    $outlog .= $buf;
 			};
 			my $err = $@;
 			if ($err) {
@@ -517,12 +518,13 @@ sub run_command {
 		} elsif ($h eq $error) {
 		    if ($errfunc || $logfunc) {
 			eval {
-			    $errlog .= $buf;
-			    while ($errlog =~ s/^([^\010\r\n]*)(\r|\n|(\010)+|\r\n)//s) {
-				my $line = $1;
+			    while ($buf =~ s/^([^\010\r\n]*)(\r|\n|(\010)+|\r\n)//s) {
+				my $line = $errlog . $1;
+				$errlog = '';
 				&$errfunc($line) if $errfunc;
 				&$logfunc($line) if $logfunc;
 			    }
+			    $errlog .= $buf;
 			};
 			my $err = $@;
 			if ($err) {