ref: a566629485f872d51d4d5661d8b4aa32bd45f3e2
dir: /extents.h/
/*
* an ordered linked list sorted by block number (->low, ->high).
* ->big or ->small sorted by size and then block number.
*/
typedef struct Extent Extent;
typedef struct Extents Extents;
/*
When allocating blocks from extents:
1. Of all the extents with the len we need, pick the extent with the lowest blkno.
2. If no extent of the len we need is available, then break up the smallest extent.
*/
struct Extent {
struct Extent *low, *high; /* sorted by blkno */
struct Extent *small, *big; /* sorted by len */
u64 blkno; /* block number */
u64 len; /* in blocks */
};
struct Extents {
Extent *lru; /* least recently used extent */
QLock el;
u32 n; /* number of extents */
};
extern int chatty9p;
void *emalloc(u32 sz);
s8 *estrdup(s8 *s);
void panic(char *fmt, ...);
s8 find(Extents *es, u64 bno);
Extent *add(Extents *es, u64 blkno, u64 len);
void showblocknos(Extents *es);
void showextents(char *msg, Extents *es);
s32 sizeofextents(Extents *es);
s32 saveextents(Extents *es, s8 *buf, u32 nbuf);
s32 loadextents(Extents *es, s8 *buf, u32 nbuf);
u64 balloc(Extents *es, u64 n);
void bfree(Extents *es, u64 blkno, u64 len);
u64 nfrees(Extents *es);
Extent *lowest(Extents *es);