dedup

commit 38a52d085bd43216bf41c277c23c0ac5ebb7f0a4
parent 76740646829a96a6f4e69082141a30886a933ffe
Author: sin <sin@2f30.org>
Date:   Thu, 25 Apr 2019 16:18:02 +0100

Add some comments

Diffstat:
M
bcompress.c
 | 
5
+++--
M
block.c
 | 
1
+
M
block.h
 | 
3
+++
M
bstorage.c
 | 
12
++++++++----

4 files changed, 15 insertions(+), 6 deletions(-)
diff --git a/bcompress.c b/bcompress.c
@@ -37,13 +37,14 @@ static struct bops bops = {
 	.close = bcclose,
 };
 
+/* Compression layer context */
 struct cctx {
-	uint64_t type;
+	uint64_t type;	/* compression algorithm type for new blocks */
 };
 
 /* Compression descriptor */
 struct cd {
-	uint64_t type;
+	uint64_t type;	/* compression algorithm type */
 	uint64_t size;
 };
 
diff --git a/block.c b/block.c
@@ -1,3 +1,4 @@
+/* Top-level block layer implementation */
 #include <sys/types.h>
 #include <sys/stat.h>
 
diff --git a/block.h b/block.h
@@ -9,6 +9,9 @@ struct bparam {
 	char *halgo;
 };
 
+/*
+ * Block operations structure.
+ * This is implemented by each of the block layers. */
 struct bops {
 	int (*creat)(struct bctx *bctx, char *path, int mode, struct bparam *bpar);
 	int (*open)(struct bctx *bctx, char *path, int flags, int mode, struct bparam *bpar);
diff --git a/bstorage.c b/bstorage.c
@@ -80,11 +80,12 @@ struct bd {
 };
 RB_HEAD(bdcache, bd);
 
+/* Storage layer context */
 struct sctx {
 	struct bdcache bdcache;
 	struct bhdr bhdr;
 	int fd;
-	int rdonly;
+	int rdonly;	/* when set to 1, the bssync() operation is a no-op */
 };
 
 #define NCALGOS	2
@@ -303,7 +304,7 @@ initbdcache(struct sctx *sctx)
 	return 0;
 }
 
-/* Create a new store */
+/* Create storage */
 static int
 bscreat(struct bctx *bctx, char *path, int mode, struct bparam *bpar)
 {
@@ -371,7 +372,7 @@ bscreat(struct bctx *bctx, char *path, int mode, struct bparam *bpar)
 	return 0;
 }
 
-/* Open an existing store */
+/* Open storage */
 static int
 bsopen(struct bctx *bctx, char *path, int flags, int mode, struct bparam *bpar)
 {
@@ -405,6 +406,7 @@ bsopen(struct bctx *bctx, char *path, int flags, int mode, struct bparam *bpar)
 		return -1;
 	}
 
+	/* Populate bparam */
 	calgo = (bhdr->flags >> CALGOSHIFT) & CALGOMASK;
 	if (calgo < 0 || calgo >= NCALGOS) {
 		free(sctx);
@@ -432,7 +434,7 @@ bsopen(struct bctx *bctx, char *path, int flags, int mode, struct bparam *bpar)
 	return 0;
 }
 
-/* Write a new block */
+/* Write a block */
 static int
 bsput(struct bctx *bctx, void *buf, size_t n, unsigned char *md)
 {
@@ -508,6 +510,7 @@ bsget(struct bctx *bctx, unsigned char *md, void *buf, size_t *n)
 	return 0;
 }
 
+/* Sync block header to storage */
 static int
 bssync(struct bctx *bctx)
 {
@@ -527,6 +530,7 @@ bssync(struct bctx *bctx)
 	return 0;
 }
 
+/* Close storage handle */
 static int
 bsclose(struct bctx *bctx)
 {