[PATCH] Fix to avoid high memory footprint

["Haritha via GitGitGadget" <gitgitgadget@gmail.com>]

From: D Harithamma <harithamma.d@ibm.com>

This fix avoids high memory footprint when
adding files that require conversion.
Git has a trace_encoding routine that prints trace
output when GIT_TRACE_WORKING_TREE_ENCODING=1 is
set. This environment variable is used to debug
the encoding contents.
When a 40MB file is added, it requests close to
1.8GB of storage from xrealloc which can lead
to out of memory errors.
However, the check for
GIT_TRACE_WORKING_TREE_ENCODING is done after
the string is allocated. This resolves high
memory footprints even when
GIT_TRACE_WORKING_TREE_ENCODING is not active.
This fix adds an early exit to avoid the
unnecessary memory allocation.

Signed-off-by: Haritha D <harithamma.d@ibm.com>
---
    Fix to avoid high memory footprint
    
    This fix avoids high memory footprint when adding files that require
    conversion
    
    Git has a trace_encoding routine that prints trace output when
    GIT_TRACE_WORKING_TREE_ENCODING=1 is set. This environment variable is
    used to debug the encoding contents. When a 40MB file is added, it
    requests close to 1.8GB of storage from xrealloc which can lead to out
    of memory errors. However, the check for GIT_TRACE_WORKING_TREE_ENCODING
    is done after the string is allocated. This resolves high memory
    footprints even when GIT_TRACE_WORKING_TREE_ENCODING is not active. This
    fix adds an early exit to avoid the unnecessary memory allocation.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1744%2FHarithaIBM%2FmemFootprintFix-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1744/HarithaIBM/memFootprintFix-v1
Pull-Request: https://github.com/git/git/pull/1744

 convert.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/convert.c b/convert.c
index d8737fe0f2d..e765bcd53d6 100644
--- a/convert.c
+++ b/convert.c
@@ -324,6 +324,11 @@ static void trace_encoding(const char *context, const char *path,
 	struct strbuf trace = STRBUF_INIT;
 	int i;
 
+	// If tracing is not on, exit early to avoid high memory footprint
+	if (!trace_pass_fl(&coe)) {
+		return;
+	}
+
 	strbuf_addf(&trace, "%s (%s, considered %s):\n", context, path, encoding);
 	for (i = 0; i < len && buf; ++i) {
 		strbuf_addf(

base-commit: 557ae147e6cdc9db121269b058c757ac5092f9c9
-- 
gitgitgadget