From: Nick Terrell <terrelln@fb.com>
Date: Mon, 12 Oct 2020 19:52:42 +0000 (-0700)
Subject: [minor] Improve docs and add an assert in response to review
X-Git-Tag: v1.4.7~58^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7e6f91ed84e62513c2d12e7e40254704f593000c;p=thirdparty%2Fzstd.git

[minor] Improve docs and add an assert in response to review
---

diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index 69ff6512d..92010fd8a 100644
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -1064,11 +1064,12 @@ U32 ZSTD_cycleLog(U32 hashLog, ZSTD_strategy strat)
 }
 
 /** ZSTD_dictAndWindowLog() :
- *  Returns an adjusted window log that is large enough to fit the source and the dictionary.
- *  The zstd format says that the entire dictionary is valid if one byte of the dictionary
- *  is within the window. So the hashLog and chainLog should be large enough to reference both
- *  the dictionary and the window. So we must use this adjusted dictAndWindowLog when downsizing
- *  the hashLog and windowLog.
+ * Returns an adjusted window log that is large enough to fit the source and the dictionary.
+ * The zstd format says that the entire dictionary is valid if one byte of the dictionary
+ * is within the window. So the hashLog and chainLog should be large enough to reference both
+ * the dictionary and the window. So we must use this adjusted dictAndWindowLog when downsizing
+ * the hashLog and windowLog.
+ * NOTE: srcSize must not be ZSTD_CONTENTSIZE_UNKNOWN.
  */
 static U32 ZSTD_dictAndWindowLog(U32 windowLog, U64 srcSize, U64 dictSize)
 {
@@ -1077,6 +1078,7 @@ static U32 ZSTD_dictAndWindowLog(U32 windowLog, U64 srcSize, U64 dictSize)
     if (dictSize == 0) {
         return windowLog;
     }
+    assert(windowLog <= ZSTD_WINDOWLOG_MAX);
     assert(srcSize != ZSTD_CONTENTSIZE_UNKNOWN); /* Handled in ZSTD_adjustCParams_internal() */
     {
         U64 const windowSize = 1ULL << windowLog;