[PATCH v2 05/10] archive-tar: allow to accumulate writes before writing 512-byte blocks

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

This allows to split single write_blocked(buf, 123) call into multiple
calls

write_blocked(buf, 100, 1);
write_blocked(buf,  23, 1);
write_blocked(buf,   0, 0);

No call sites do this yet though.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 archive-tar.c |   16 +++++++++-------
 1 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/archive-tar.c b/archive-tar.c
index 3be0cdf..9060f9a 100644
--- a/archive-tar.c
+++ b/archive-tar.c
@@ -30,7 +30,7 @@ static void write_if_needed(void)
  * queues up writes, so that all our write(2) calls write exactly one
  * full block; pads writes to RECORDSIZE
  */
-static void write_blocked(const void *data, unsigned long size)
+static void write_blocked(const void *data, unsigned long size, int partial)
 {
 	const char *buf = data;
 	unsigned long tail;
@@ -54,6 +54,8 @@ static void write_blocked(const void *data, unsigned long size)
 		memcpy(block + offset, buf, size);
 		offset += size;
 	}
+	if (partial)
+		return;
 	tail = offset % RECORDSIZE;
 	if (tail)  {
 		memset(block + offset, 0, RECORDSIZE - tail);
@@ -155,8 +157,8 @@ static int write_extended_header(struct archiver_args *args,
 	mode = 0100666;
 	sprintf(header.name, "%s.paxheader", sha1_to_hex(sha1));
 	prepare_header(args, &header, mode, size);
-	write_blocked(&header, sizeof(header));
-	write_blocked(buffer, size);
+	write_blocked(&header, sizeof(header), 0);
+	write_blocked(buffer, size, 0);
 	return 0;
 }
 
@@ -234,9 +236,9 @@ static int write_tar_entry(struct archiver_args *args,
 		}
 	}
 	strbuf_release(&ext_header);
-	write_blocked(&header, sizeof(header));
+	write_blocked(&header, sizeof(header), 0);
 	if (S_ISREG(mode) && buffer && size > 0)
-		write_blocked(buffer, size);
+		write_blocked(buffer, size, 0);
 	free(buffer);
 	return err;
 }
@@ -255,8 +257,8 @@ static int write_global_extended_header(struct archiver_args *args)
 	mode = 0100666;
 	strcpy(header.name, "pax_global_header");
 	prepare_header(args, &header, mode, ext_header.len);
-	write_blocked(&header, sizeof(header));
-	write_blocked(ext_header.buf, ext_header.len);
+	write_blocked(&header, sizeof(header), 0);
+	write_blocked(ext_header.buf, ext_header.len, 0);
 	strbuf_release(&ext_header);
 	return err;
 }
-- 
1.7.8.36.g69ee2