diff options
| -rw-r--r-- | libstore/store.h | 75 |
1 files changed, 62 insertions, 13 deletions
diff --git a/libstore/store.h b/libstore/store.h index f6487cd6..1ffb4c3f 100644 --- a/libstore/store.h +++ b/libstore/store.h @@ -42,11 +42,15 @@ struct store address space. In units of BLOCK_SIZE, below. */ off_t *runs; /* Malloced */ size_t runs_len; /* Length of RUNS. */ - off_t end; /* Maximum valid offset. */ - off_t wrap; /* If 0, no wrap, otherwise RUNS describes a - repeating pattern, of length WRAP -- each - successive iteration having an additional - offset of WRAP. */ + + /* Maximum valid offset. This is the same as SIZE, but in blocks. */ + off_t end; + + /* WRAP_SRC is the sum of the run lengths in RUNS. If this is less than + END, then RUNS describes a repeating pattern, of length WRAP_SRC -- each + successive iteration having an additional offset of WRAP_DST. */ + off_t wrap_src; + off_t wrap_dst; /* Only meaningful if WRAP_SRC < END */ /* Handles for the underlying storage. */ char *name; /* Malloced */ @@ -89,6 +93,7 @@ struct store_meths /* Write up to LEN bytes from BUF to the storage at the underlying address ADDR. INDEX varies from 0 to the number of runs in STORE. */ store_write_meth_t write; + /* Called just before deallocating STORE. */ void (*cleanup) (struct store *store); }; @@ -119,19 +124,18 @@ error_t _store_file_create (file_t file, size_t block_size, struct store **store); /* Return a new store in STORE that interleaves all the stores in STRIPES - (NUM_STRIPES of them) every INTERLEAVE blocks (every store in STRIPES must - have the same block size). If DEALLOC is true, then the striped stores - are freed when this store is (in any case, the array STRIPES is copied, - and so should be freed by the caller). */ + (NUM_STRIPES of them) every INTERLEAVE bytes; INTERLEAVE must be an + integer multiple of each stripe's block size. If DEALLOC is true, then + the striped stores are freed when this store is (in any case, the array + STRIPES is copied, and so should be freed by the caller). */ error_t store_ileave_create (struct store **stripes, size_t num_stripes, int dealloc, off_t interleave, struct store **store); /* Return a new store in STORE that concatenates all the stores in STORES - (NUM_STORES of them) every store in STRIPES must have the same block size. - If DEALLOC is true, then the sub-stores are freed when this store is (in - any case, the array STORES is copied, and so should be freed by the - caller). */ + (NUM_STORES of them). If DEALLOC is true, then the sub-stores are freed + when this store is (in any case, the array STORES is copied, and so should + be freed by the caller). */ error_t store_concat_create (struct store **stores, size_t num_stores, int dealloc, struct store **store); @@ -190,5 +194,50 @@ error_t store_create_pager (struct store *store, vm_prot_t prot, ..., mach_port_t *pager) #endif + +/* Encode/decode table: + + 4 vectors are used: ports, ints, offsets (off_t), and data (char); + each type of store uses the following entries in each vector: + + -type- -ports- -ints- -offsets- -data- -kids- + device DEVICE TY, FL, BS, NR, NL, ML NR * (OFFS, LEN) NL + ML - + file FILE TY, FL, BS, NR, NL, ML NR * (OFFS, LEN) NL + ML - + memory MEMOBJ TY, FL, BS, NR, NL, ML NR * (OFFS, LEN) NL + ML - + task TASK TY, FL, BS, NR, NL, ML NR * (OFFS, LEN) NL + ML - + (the data for the above is a name (incl '\0') and a misc data block) + null - TY, FL LEN - - + (BS is 1) + ileave - TY, FL, IL, NC - - NC + (BS is the LCM of its children; LEN is the minimum of theirs * IL) + concat - TY, FL, NC - - NC + (BS is the LCM of its children; LEN is the sum of theirs) + layer - TY, FL, NC - - NC + (BS is the LCM of its children; LEN is the minimum of theirs) + + For ileave, concat, and layer, the children are encoded following the parent. + + key: TY = type code, FL = flags, BS = block size, NR = num runs, + NL = name len, ML = misc len, NC = num children, + IL = interleave (bytes), + LEN = run length (blocks), OFFS = run offset (blocks), + */ + +/* Encode STORE into the given arrays, suitable for passing back using + file_get_storage_info. */ +error_t store_encode (const struct store *store, + mach_port_t **ports, mach_msg_type_number_t *ports_len, + int **ints, mach_msg_type_number_t *ints_len, + off_t **offsets, mach_msg_type_number_t *offsets_len, + char **data, mach_msg_type_number_t *data_len); + +/* Decode the given arrays, as fetched using file_get_storage_info, and + either create a new store from them, which return in STORE, or return an + error. */ +error_t store_decode (mach_port_t *ports, mach_msg_type_number_t ports_len, + int *ints, mach_msg_type_number_t ints_len, + off_t *offsets, mach_msg_type_number_t offsets_len, + char *data, mach_msg_type_number_t data_len, + struct store **store); #endif /* __STORE_H__ */ |