talons

commit 2edb13e5831d2e8b17274cf628a1ff1399da7bfd
parent cb3f6bfba779f53100a9b21c09cb9489ad7469d0
Author: Colin Leroy <colin@colino.net>
Date:   Wed, 10 Oct 2018 10:09:11 +0200

Comment the my_tmpfile_with_len() function.

Diffstat:
M
src/common/file-utils.c
 | 
13
+++++++++++++

1 file changed, 13 insertions(+), 0 deletions(-)
diff --git a/src/common/file-utils.c b/src/common/file-utils.c
@@ -827,6 +827,19 @@ FILE *my_tmpfile(void)
 	return tmpfile();
 }
 
+/* Returns a memory-backed FILE pointer to avoid file I/O
+ * where unnecessary. The "file" size is passed in the len
+ * parameter and is fixed: it's up to the caller to pass a
+ * large enough length to write to the FILE pointer. If the
+ * precise length isn't known, it is possible to ask for more.
+ * 
+ * In this case, once writing to the pointer is done, the 
+ * caller is responsible to call ftruncate(fileno(fp), ftell(fp))
+ * to make sure re-reading the stream will return EOF at the
+ * end of what we wrote. 
+ * Otherwise, re-reading the stream will return uninitialized
+ * memory at the end of the stream.
+ */
 FILE *my_tmpfile_with_len(size_t len)
 {
 #if HAVE_FMEMOPEN