From 879372eb72d8b8a073f4f73d98caa1cd15971bd5 Mon Sep 17 00:00:00 2001 From: Dave Borowitz Date: Thu, 11 Jan 2018 13:14:02 -0500 Subject: [PATCH] DfsReaderIoStats: Clarify that "blocks" are really cache misses The previous wording was ambiguous as to whether these were blocks requested from the cache (hits + misses) or read from underlying storage (misses only). They are in fact recording only misses: Accumulator#{readBlock,readBlockBytes,readBlockMicros} are only incremented from BlockBasedFile#readOneBlock, which is only called from the cache miss path in DfsBlockCache#getOrLoad (line 391). Change-Id: I0135cd1e76d09c1e28e0f1833b34c312511c66ce --- .../internal/storage/dfs/DfsReaderIoStats.java | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsReaderIoStats.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsReaderIoStats.java index cf925c914..c35801f3b 100644 --- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsReaderIoStats.java +++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsReaderIoStats.java @@ -67,10 +67,16 @@ public class DfsReaderIoStats { /** Total number of block cache hits. */ long blockCacheHit; - /** Total number of discrete blocks read from pack file(s). */ + /** + * Total number of discrete blocks actually read from pack file(s), that is, + * block cache misses. + */ long readBlock; - /** Total number of compressed bytes read as block sized units. */ + /** + * Total number of compressed bytes read during cache misses, as block sized + * units. + */ long readBlockBytes; /** Total microseconds spent reading {@link #readBlock} blocks. */ @@ -144,7 +150,8 @@ public class DfsReaderIoStats { } /** - * Get total number of discrete blocks read from pack file(s). + * Get total number of discrete blocks actually read from pack file(s), that + * is, block cache misses. * * @return total number of discrete blocks read from pack file(s). */ @@ -153,7 +160,8 @@ public class DfsReaderIoStats { } /** - * Get total number of compressed bytes read as block sized units. + * Get total number of compressed bytes read during cache misses, as block + * sized units. * * @return total number of compressed bytes read as block sized units. */ @@ -162,7 +170,7 @@ public class DfsReaderIoStats { } /** - * Get total microseconds spent reading blocks. + * Get total microseconds spent reading blocks during cache misses. * * @return total microseconds spent reading blocks. */