added bounding to compression level change
diff --git a/contrib/adaptive-compression/adapt.c b/contrib/adaptive-compression/adapt.c
index 758bf55..c542c9a 100644
--- a/contrib/adaptive-compression/adapt.c
+++ b/contrib/adaptive-compression/adapt.c
@@ -323,20 +323,23 @@
if (1 - createCompletion > threshold) {
/* job creation was not finished, compression thread waited */
unsigned const change = MAX_COMPRESSION_LEVEL_CHANGE - createCompletion * MAX_COMPRESSION_LEVEL_CHANGE;
+ unsigned const boundChange = MIN(change, ZSTD_maxCLevel() - ctx->compressionLevel);
DEBUG(2, "increasing compression level %u by %u\n", ctx->compressionLevel, change);
- ctx->compressionLevel += change;
+ ctx->compressionLevel += boundChange;
}
else if (1 - writeCompletion > threshold) {
/* write thread was not finished, compression thread waited */
unsigned const change = MAX_COMPRESSION_LEVEL_CHANGE - writeCompletion * MAX_COMPRESSION_LEVEL_CHANGE;
+ unsigned const boundChange = MIN(change, ZSTD_maxCLevel() - ctx->compressionLevel);
DEBUG(2, "increasing compression level %u by %u\n", ctx->compressionLevel, change);
- ctx->compressionLevel += change;
+ ctx->compressionLevel += boundChange;
}
else if (1 - compressionCompletion > threshold) {
/* compression thread was not finished, one of the other two threads waited */
unsigned const change = MAX_COMPRESSION_LEVEL_CHANGE - compressionCompletion * MAX_COMPRESSION_LEVEL_CHANGE;
+ unsigned const boundChange = MIN(change, ctx->compressionLevel - 1);
DEBUG(2, "decreasing compression level %u by %u\n", ctx->compressionLevel, change);
- ctx->compressionLevel -= change;
+ ctx->compressionLevel -= boundChange;
}
/* reset */
pthread_mutex_lock(&ctx->completion_mutex.pMutex);