dedup

commit 0b71c907f1b957781c5850a7445e3fd6abbdfb43
parent 51940c0f0f8def58517f3ef932b9b657cf556f18
Author: sin <sin@2f30.org>
Date:   Sun, 12 May 2019 20:14:09 +0100

Split some more pack/unpack from write/read

Diffstat:
M
bstorage.c
 | 
63
++++++++++++++++++++++++++++++++++-----------------------------

1 file changed, 34 insertions(+), 29 deletions(-)
diff --git a/bstorage.c b/bstorage.c
@@ -154,18 +154,11 @@ packbhdr(unsigned char *buf, struct bhdr *bhdr)
 
 /* Unpack block descriptor */
 static int
-unpackbd(int fd, struct bd *bd)
+unpackbd(unsigned char *buf, struct bd *bd)
 {
-	unsigned char buf[BDSIZE];
 	char fmt[BUFSIZ];
 	int n;
 
-	if (xread(fd, buf, BDSIZE) != BDSIZE) {
-		seterr("failed to read block descriptor: %s",
-		        strerror(errno));
-		return -1;
-	}
-
 	snprintf(fmt, sizeof(fmt), "s'6qqq'%d", MDSIZE);
 	n = unpack(buf, fmt,
 	           &bd->type,
@@ -181,9 +174,8 @@ unpackbd(int fd, struct bd *bd)
 
 /* Write block descriptor */
 static int
-packbd(int fd, struct bd *bd)
+packbd(unsigned char *buf, struct bd *bd)
 {
-	unsigned char buf[BDSIZE];
 	char fmt[BUFSIZ];
 	int n;
 
@@ -197,11 +189,6 @@ packbd(int fd, struct bd *bd)
 	         bd->md);
 
 	assert(n == BDSIZE);
-	if (xwrite(fd, buf, n) != n) {
-		seterr("failed to write block descriptor: %s",
-		        strerror(errno));
-		return -1;
-	}
 	return n;
 }
 
@@ -209,6 +196,7 @@ packbd(int fd, struct bd *bd)
 static int
 loadbd(struct sctx *sctx)
 {
+	unsigned char bdbuf[BDSIZE];
 	struct bd *bd;
 
 	bd = calloc(1, sizeof(*bd));
@@ -217,10 +205,13 @@ loadbd(struct sctx *sctx)
 		return -1;
 	}
 
-	if (unpackbd(sctx->fd, bd) < 0) {
+	if (xread(sctx->fd, bdbuf, BDSIZE) != BDSIZE) {
 		free(bd);
+		seterr("failed to read block descriptor: %s",
+		        strerror(errno));
 		return -1;
 	}
+	unpackbd(bdbuf, bd);
 
 	if (bd->type != BDTYPE) {
 		free(bd);
@@ -287,7 +278,7 @@ initbdcache(struct sctx *sctx)
 static int
 bscreat(struct bctx *bctx, char *path, int mode)
 {
-	unsigned char buf[BHDRSIZE];
+	unsigned char bhdrbuf[BHDRSIZE];
 	struct sctx *sctx;
 	struct bhdr *bhdr;
 	int fd;
@@ -320,8 +311,8 @@ bscreat(struct bctx *bctx, char *path, int mode)
 	bhdr->flags = (VMAJ << VMAJSHIFT) | VMIN;
 	bhdr->nbd = 0;
 
-	packbhdr(buf, bhdr);
-	if (xwrite(fd, buf, BHDRSIZE) != BHDRSIZE) {
+	packbhdr(bhdrbuf, bhdr);
+	if (xwrite(fd, bhdrbuf, BHDRSIZE) != BHDRSIZE) {
 		free(sctx);
 		close(fd);
 		seterr("failed to write block header: %s", strerror(errno));
@@ -334,7 +325,7 @@ bscreat(struct bctx *bctx, char *path, int mode)
 static int
 bsopen(struct bctx *bctx, char *path, int flags, int mode)
 {
-	unsigned char buf[BHDRSIZE];
+	unsigned char bhdrbuf[BHDRSIZE];
 	struct sctx *sctx;
 	struct bhdr *bhdr;
 	int fd, algo;
@@ -374,13 +365,13 @@ bsopen(struct bctx *bctx, char *path, int flags, int mode)
 	SLIST_INIT(&sctx->gchead);
 	bhdr = &sctx->bhdr;
 
-	if (xread(fd, buf, BHDRSIZE) != BHDRSIZE) {
+	if (xread(fd, bhdrbuf, BHDRSIZE) != BHDRSIZE) {
 		free(sctx);
 		close(fd);
 		seterr("failed to read block header: %s", strerror(errno));
 		return -1;
 	}
-	unpackbhdr(buf, bhdr);
+	unpackbhdr(bhdrbuf, bhdr);
 
 	if (memcmp(bhdr->magic, BHDRMAGIC, NBHDRMAGIC) != 0) {
 		free(sctx);
@@ -412,6 +403,7 @@ bsopen(struct bctx *bctx, char *path, int flags, int mode)
 static int
 bsput(struct bctx *bctx, void *buf, size_t n, unsigned char *md)
 {
+	unsigned char bdbuf[BDSIZE];
 	struct sctx *sctx;
 	struct bhdr *bhdr;
 	struct bd key, *bd;
@@ -439,8 +431,11 @@ bsput(struct bctx *bctx, void *buf, size_t n, unsigned char *md)
 		}
 
 		bd->refcnt++;
-		if (packbd(sctx->fd, bd) < 0) {
+		packbd(bdbuf, bd);
+		if (xwrite(sctx->fd, bdbuf, BDSIZE) != BDSIZE) {
 			bd->refcnt--;
+			seterr("failed to write block descriptor: %s",
+			        strerror(errno));
 			return -1;
 		}
 
@@ -466,8 +461,13 @@ bsput(struct bctx *bctx, void *buf, size_t n, unsigned char *md)
 	bd->refcnt = 1;
 	memcpy(bd->md, key.md, MDSIZE);
 
-	if (packbd(sctx->fd, bd) < 0) {
+	packbd(bdbuf, bd);
+	if (xwrite(sctx->fd, bdbuf, BDSIZE) != BDSIZE) {
+		/* Shouldn't fail but if it does rewind storage file state */
+		ftruncate(sctx->fd, offs);
 		free(bd);
+		seterr("failed to write block descriptor: %s",
+		        strerror(errno));
 		return -1;
 	}
 
@@ -528,6 +528,7 @@ bsget(struct bctx *bctx, unsigned char *md, void *buf, size_t *n)
 static int
 bsrm(struct bctx *bctx, unsigned char *md)
 {
+	unsigned char bdbuf[BDSIZE];
 	struct sctx *sctx;
 	struct bd key, *bd;
 	off_t bdoffs;
@@ -547,8 +548,11 @@ bsrm(struct bctx *bctx, unsigned char *md)
 	}
 
 	bd->refcnt--;
-	if (packbd(sctx->fd, bd) < 0) {
+	packbd(bdbuf, bd);
+	if (xwrite(sctx->fd, bdbuf, BDSIZE) != BDSIZE) {
 		bd->refcnt++;
+		seterr("failed to write block descriptor: %s",
+		        strerror(errno));
 		return -1;
 	}
 
@@ -563,7 +567,8 @@ bsrm(struct bctx *bctx, unsigned char *md)
 		 */
 		lseek(sctx->fd, bdoffs, SEEK_SET);
 		bd->refcnt++;
-		packbd(sctx->fd, bd);
+		packbd(bdbuf, bd);
+		xwrite(sctx->fd, bdbuf, BDSIZE);
 		seterr("operation not supported");
 		return -1;
 	}
@@ -657,7 +662,7 @@ bscheck(struct bctx *bctx, unsigned char *md)
 static int
 bssync(struct bctx *bctx)
 {
-	unsigned char buf[BHDRSIZE];
+	unsigned char bhdrbuf[BHDRSIZE];
 	struct sctx *sctx;
 	struct bhdr *bhdr;
 
@@ -671,8 +676,8 @@ bssync(struct bctx *bctx)
 	}
 
 	bhdr = &sctx->bhdr;
-	packbhdr(buf, bhdr);
-	if (xwrite(sctx->fd, buf, BHDRSIZE) != BHDRSIZE) {
+	packbhdr(bhdrbuf, bhdr);
+	if (xwrite(sctx->fd, bhdrbuf, BHDRSIZE) != BHDRSIZE) {
 		seterr("failed to write block header: %s", strerror(errno));
 		return -1;
 	}