From: Yann Collet <cyan@fb.com>
Date: Fri, 17 Aug 2018 23:20:27 +0000 (-0700)
Subject: fix : no longer slow down on input saturation
X-Git-Tag: v1.3.6^2~19^2~14
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=09e63c58ac38503b2338ac01229681048f0e3648;p=thirdparty%2Fzstd.git

fix : no longer slow down on input saturation

only slows down when all buffers are full
---

diff --git a/programs/fileio.c b/programs/fileio.c
index 02da1df95..fcb43030a 100644
--- a/programs/fileio.c
+++ b/programs/fileio.c
@@ -808,9 +808,12 @@ FIO_compressZstdFrame(const cRess_t* ressPtr,
 
                     cpszfp = zfp;
 
-                    if ( (zfp.ingested == cpszfp.ingested)
-                      && (zfp.consumed == cpszfp.consumed) ) {
-                        DISPLAYLEVEL(2, "no data read nor consumed : buffers are full (?) output is too slow => slow down ; or compression is slow + input has reached its limit => can't tell \n")
+                    if ( (zfp.ingested == cpszfp.ingested)   /* no data read : input buffer full */
+                      && (zfp.consumed == cpszfp.consumed)   /* no data compressed : no more buffer to compress OR compression is really slow */
+                      && (zfp.nbActiveWorkers == 0)          /* confirmed : no compression : either no more buffer to compress OR not enough data to start first worker */
+                      && (zfp.currentJobID > 0)              /* first job started : only remaining reason is no more available buffer to start compression */
+                      ) {
+                        DISPLAYLEVEL(6, "all buffers full : compression stopped => slow down \n")
                         speedChange = slower;
                     }