dedup

commit bb81bcb6bd4b4bf7dbe36d2a47087dec0c58f812
parent 8728669764d059ab08e07111ca630f7fa313e51d
Author: sin <sin@2f30.org>
Date:   Wed,  1 May 2019 14:33:42 +0100

Shorten type width to 16 bits and mark rest as reserved

Diffstat:
M
bcompress.c
 | 
11
+++++++----
M
bstorage.c
 | 
9
++++++---

2 files changed, 13 insertions(+), 7 deletions(-)
diff --git a/bcompress.c b/bcompress.c
@@ -45,12 +45,13 @@ static struct bops bops = {
 
 /* Compression layer context */
 struct cctx {
-	uint64_t type;	/* compression algorithm type for new blocks */
+	int type;	/* compression algorithm type for new blocks */
 };
 
 /* Compression descriptor */
 struct cd {
-	uint64_t type;	/* compression algorithm type */
+	uint16_t type;	/* compression algorithm type */
+	uint8_t reserved[6];
 	uint64_t size;
 };
 
@@ -60,8 +61,9 @@ unpackcd(void *buf, struct cd *cd)
 {
 	int n;
 
-	n = unpack(buf, "qq",
+	n = unpack(buf, "s'6q",
 	           &cd->type,
+	           cd->reserved,
 	           &cd->size);
 
 	assert(n == CDSIZE);
@@ -74,8 +76,9 @@ packcd(void *buf, struct cd *cd)
 {
 	int n;
 
-	n = pack(buf, "qq",
+	n = pack(buf, "s'6q",
 	         cd->type,
+	         cd->reserved,
 	         cd->size);
 
 	assert(n == CDSIZE);
diff --git a/bstorage.c b/bstorage.c
@@ -87,7 +87,8 @@ struct bhdr {
 
 /* Block descriptor */
 struct bd {
-	uint64_t type;
+	uint16_t type;
+	uint8_t reserved[6];
 	uint64_t offset;	/* offset of block */
 	uint64_t size;		/* size of block */
 	uint64_t refcnt;
@@ -194,9 +195,10 @@ unpackbd(int fd, struct bd *bd)
 	if (xread(fd, buf, sizeof(buf)) != sizeof(buf))
 		return -1;
 
-	snprintf(fmt, sizeof(fmt), "qqqq'%d", MDSIZE);
+	snprintf(fmt, sizeof(fmt), "s'6qqq'%d", MDSIZE);
 	n = unpack(buf, fmt,
 	           &bd->type,
+	           bd->reserved,
 	           &bd->offset,
 	           &bd->size,
 	           &bd->refcnt,
@@ -214,9 +216,10 @@ packbd(int fd, struct bd *bd)
 	char fmt[BUFSIZ];
 	int n;
 
-	snprintf(fmt, sizeof(fmt), "qqqq'%d", MDSIZE);
+	snprintf(fmt, sizeof(fmt), "s'6qqq'%d", MDSIZE);
 	n = pack(buf, fmt,
 	         bd->type,
+	         bd->reserved,
 	         bd->offset,
 	         bd->size,
 	         bd->refcnt,