From c4d2c6c6753fd2c41c3db1877c5c46613dc45510 Mon Sep 17 00:00:00 2001
From: sr
Date: Thu, 25 Jul 2013 23:44:18 +0200
Subject: Work in progress: uplink

---
 src/server/image.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

(limited to 'src/server/image.h')

diff --git a/src/server/image.h b/src/server/image.h
index 7a4e72e..6910395 100644
--- a/src/server/image.h
+++ b/src/server/image.h
@@ -10,6 +10,8 @@ extern pthread_spinlock_t _images_lock;
 
 int image_is_complete(dnbd3_image_t *image);
 
+void image_update_cachemap( dnbd3_image_t *image, uint64_t start, uint64_t end, const int set );
+
 int image_save_cache_map(dnbd3_image_t *image);
 
 dnbd3_image_t* image_get(char *name, uint16_t revision);
@@ -23,4 +25,17 @@ int image_load_all(char *path);
 
 int image_generate_crc_file(char *image);
 
+// one byte in the map covers 8 4kib blocks, so 32kib per byte
+// "+ (1 << 15) - 1" is required to account for the last bit of
+// the image that is smaller than 32kib
+// this would be the case whenever the image file size is not a
+// multiple of 32kib (= the number of blocks is not divisible by 8)
+// ie: if the image is 49152 bytes and you do 49152 >> 15 you get 1,
+// but you actually need 2 bytes to have a complete cache map
+#define IMGSIZE_TO_MAPBYTES(bytes) ((int)(((bytes) + (1 << 15) - 1) >> 15))
+
+// calculate number of hash blocks in file. One hash block is 16MiB
+#define HASH_BLOCK_SIZE ((int64_t)(1 << 24))
+#define IMGSIZE_TO_HASHBLOCKS(bytes) ((int)(((bytes) + HASH_BLOCK_SIZE - 1) / HASH_BLOCK_SIZE))
+
 #endif
-- 
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